National Library of Energy BETA

Sample records for fracture zones faults

  1. Modeling of fault activation and seismicity by injection directly into a fault zone associated with hydraulic fracturing of shale-gas reservoirs

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Rutqvist, Jonny; Rinaldi, Antonio P.; Cappa, Frédéric; Moridis, George J.

    2015-03-01

    We conducted three-dimensional coupled fluid-flow and geomechanical modeling of fault activation and seismicity associated with hydraulic fracturing stimulation of a shale-gas reservoir. We simulated a case in which a horizontal injection well intersects a steeply dip- ping fault, with hydraulic fracturing channeled within the fault, during a 3-hour hydraulic fracturing stage. Consistent with field observations, the simulation results show that shale-gas hydraulic fracturing along faults does not likely induce seismic events that could be felt on the ground surface, but rather results in numerous small microseismic events, as well as aseismic deformations along with the fracture propagation. The calculated seismicmore » moment magnitudes ranged from about -2.0 to 0.5, except for one case assuming a very brittle fault with low residual shear strength, for which the magnitude was 2.3, an event that would likely go unnoticed or might be barely felt by humans at its epicenter. The calculated moment magnitudes showed a dependency on injection depth and fault dip. We attribute such dependency to variation in shear stress on the fault plane and associated variation in stress drop upon reactivation. Our simulations showed that at the end of the 3-hour injection, the rupture zone associated with tensile and shear failure extended to a maximum radius of about 200 m from the injection well. The results of this modeling study for steeply dipping faults at 1000 to 2500 m depth is in agreement with earlier studies and field observations showing that it is very unlikely that activation of a fault by shale-gas hydraulic fracturing at great depth (thousands of meters) could cause felt seismicity or create a new flow path (through fault rupture) that could reach shallow groundwater resources.« less

  2. Modeling of fault activation and seismicity by injection directly into a fault zone associated with hydraulic fracturing of shale-gas reservoirs

    SciTech Connect (OSTI)

    Rutqvist, Jonny; Rinaldi, Antonio P.; Cappa, Frédéric; Moridis, George J.

    2015-03-01

    We conducted three-dimensional coupled fluid-flow and geomechanical modeling of fault activation and seismicity associated with hydraulic fracturing stimulation of a shale-gas reservoir. We simulated a case in which a horizontal injection well intersects a steeply dip- ping fault, with hydraulic fracturing channeled within the fault, during a 3-hour hydraulic fracturing stage. Consistent with field observations, the simulation results show that shale-gas hydraulic fracturing along faults does not likely induce seismic events that could be felt on the ground surface, but rather results in numerous small microseismic events, as well as aseismic deformations along with the fracture propagation. The calculated seismic moment magnitudes ranged from about -2.0 to 0.5, except for one case assuming a very brittle fault with low residual shear strength, for which the magnitude was 2.3, an event that would likely go unnoticed or might be barely felt by humans at its epicenter. The calculated moment magnitudes showed a dependency on injection depth and fault dip. We attribute such dependency to variation in shear stress on the fault plane and associated variation in stress drop upon reactivation. Our simulations showed that at the end of the 3-hour injection, the rupture zone associated with tensile and shear failure extended to a maximum radius of about 200 m from the injection well. The results of this modeling study for steeply dipping faults at 1000 to 2500 m depth is in agreement with earlier studies and field observations showing that it is very unlikely that activation of a fault by shale-gas hydraulic fracturing at great depth (thousands of meters) could cause felt seismicity or create a new flow path (through fault rupture) that could reach shallow groundwater resources.

  3. Development of Characterization Technology for Fault Zone Hydrology

    SciTech Connect (OSTI)

    Karasaki, Kenzi; Onishi, Tiemi; Gasperikova, Erika; Goto, Junichi; Tsuchi, Hiroyuki; Miwa, Tadashi; Ueta, Keiichi; Kiho, Kenzo; MIyakawa, Kimio

    2010-08-06

    Several deep trenches were cut, and a number of geophysical surveys were conducted across the Wildcat Fault in the hills east of Berkeley, California. The Wildcat Fault is believed to be a strike-slip fault and a member of the Hayward Fault System, with over 10 km of displacement. So far, three boreholes of ~;; 150m deep have been core-drilled and borehole geophysical logs were conducted. The rocks are extensively sheared and fractured; gouges were observed at several depths and a thick cataclasitic zone was also observed. While confirming some earlier, published conclusions from shallow observations about Wildcat, some unexpected findings were encountered. Preliminary analysis indicates that Wildcat near the field site consists of multiple faults. The hydraulic test data suggest the dual properties of the hydrologic structure of the fault zone. A fourth borehole is planned to penetrate the main fault believed to lie in-between the holes. The main philosophy behind our approach for the hydrologic characterization of such a complex fractured system is to let the system take its own average and monitor a long term behavior instead of collecting a multitude of data at small length and time scales, or at a discrete fracture scale and to ?up-scale,? which is extremely tenuous.

  4. Development of Hydrologic Characterization Technology of Fault Zones

    SciTech Connect (OSTI)

    Karasaki, Kenzi; Onishi, Tiemi; Wu, Yu-Shu

    2008-03-31

    Through an extensive literature survey we find that there is very limited amount of work on fault zone hydrology, particularly in the field using borehole testing. The common elements of a fault include a core, and damage zones. The core usually acts as a barrier to the flow across it, whereas the damage zone controls the flow either parallel to the strike or dip of a fault. In most of cases the damage zone isthe one that is controlling the flow in the fault zone and the surroundings. The permeability of damage zone is in the range of two to three orders of magnitude higher than the protolith. The fault core can have permeability up to seven orders of magnitude lower than the damage zone. The fault types (normal, reverse, and strike-slip) by themselves do not appear to be a clear classifier of the hydrology of fault zones. However, there still remains a possibility that other additional geologic attributes and scaling relationships can be used to predict or bracket the range of hydrologic behavior of fault zones. AMT (Audio frequency Magneto Telluric) and seismic reflection techniques are often used to locate faults. Geochemical signatures and temperature distributions are often used to identify flow domains and/or directions. ALSM (Airborne Laser Swath Mapping) or LIDAR (Light Detection and Ranging) method may prove to be a powerful tool for identifying lineaments in place of the traditional photogrammetry. Nonetheless not much work has been done to characterize the hydrologic properties of faults by directly testing them using pump tests. There are some uncertainties involved in analyzing pressure transients of pump tests: both low permeability and high permeability faults exhibit similar pressure responses. A physically based conceptual and numerical model is presented for simulating fluid and heat flow and solute transport through fractured fault zones using a multiple-continuum medium approach. Data from the Horonobe URL site are analyzed to demonstrate the proposed approach and to examine the flow direction and magnitude on both sides of a suspected fault. We describe a strategy for effective characterization of fault zone hydrology. We recommend conducting a long term pump test followed by a long term buildup test. We do not recommend isolating the borehole into too many intervals. We do recommend ensuring durability and redundancy for long term monitoring.

  5. Stress and fault rock controls on fault zone hydrology, Coso...

    Open Energy Info (EERE)

    fracture networks play only a minor role in fluid flow despite locally high fracture density and some fractures well-oriented for slip. At the surface, hydrothermal activity is...

  6. The Owens Valley Fault Zone Eastern California and Surface Faulting...

    Open Energy Info (EERE)

    it steps 3 km to the left and continues northwest across Crater Mountain and through Big Pine. The fault has an overall strike of 340 and dip of 8015 ENE. Surface...

  7. Stepover or Relay Ramp in Normal Fault Zones | Open Energy Information

    Open Energy Info (EERE)

    intersections between the overlapping fault strands results in increased fracture density that enhances hydrothermal fluid flow. Other definitions:Wikipedia Reegle Controlling...

  8. Uncertainty quantification for evaluating the impacts of fracture zone on

    Office of Scientific and Technical Information (OSTI)

    pressure build-up and ground surface uplift during geological CO₂ sequestration (Journal Article) | SciTech Connect Uncertainty quantification for evaluating the impacts of fracture zone on pressure build-up and ground surface uplift during geological CO₂ sequestration Citation Details In-Document Search Title: Uncertainty quantification for evaluating the impacts of fracture zone on pressure build-up and ground surface uplift during geological CO₂ sequestration A series of numerical

  9. When did movement begin on the Furnace Creek fault zone

    SciTech Connect (OSTI)

    Reheis, M. )

    1993-04-01

    About 50 km of post-Jurassic right-lateral slip has occurred on the northern part of the Furnace Creek fault zone (FCFZ). The sedimentology, stratigraphy, and structure of Tertiary rocks suggest that movement on the fault began no earlier than 12--8 Ma and possibly as late as 5--4 Ma. Large remnants of erosion surfaces occur on both sides of the FCFZ in the southern White Mountains and Fish Lake Valley and are buried by rhyolite and basalt, mostly 12--10 Ma; the ash flows and welded tuffs were likely erupted from sources at least 40 km to the east. Thus, the area probably had gentle topography, suggesting a lengthy period of pre-late Miocene tectonic stability. On the west side of the FCFZ, Cambrian sedimentary rocks are buried by a fanglomerate with an [sup [minus

  10. Area balance and strain in an extensional fault system: Strategies for improved oil recovery in fractured chalk, Gilbertown Field, southwestern Alabama. Final report, March 1996--September 1998

    SciTech Connect (OSTI)

    Pashin, J.C.; Raymond, D.E.; Rindsberg, A.K.; Alabi, G.G.; Carroll, R.E.; Groshong, R.H.; Jin, G.

    1998-12-01

    This project was designed to analyze the structure of Mesozoic and Tertiary strata in Gilbertown Field and adjacent areas to suggest ways in which oil recovery can be improved. The Eutaw Formation comprises 7 major flow units and is dominated by low-resistivity, low-contrast play that is difficult to characterize quantitatively. Selma chalk produces strictly from fault-related fractures that were mineralized as warm fluid migrated from deep sources. Resistivity, dipmeter, and fracture identification logs corroborate that deformation is concentrated in the hanging-wall drag zones. New area balancing techniques were developed to characterize growth strata and confirm that strain is concentrated in hanging-wall drag zones. Curvature analysis indicates that the faults contain numerous fault bends that influence fracture distribution. Eutaw oil is produced strictly from footwall uplifts, whereas Selma oil is produced from fault-related fractures. Clay smear and mineralization may be significant trapping mechanisms in the Eutaw Formation. The critical seal for Selma reservoirs, by contrast, is where Tertiary clay in the hanging wall is juxtaposed with poorly fractured Selma chalk in the footwall. Gilbertown Field can be revitalized by infill drilling and recompletion of existing wells. Directional drilling may be a viable technique for recovering untapped oil from Selma chalk. Revitalization is now underway, and the first new production wells since 1985 are being drilled in the western part of the field.

  11. Coiled tubing isolates zones, fractures wells with single trip service

    SciTech Connect (OSTI)

    Silverman, S.A.

    1999-04-01

    A system has been devised that combines high pressure coiled tubing (CT) and a selective isolation technique to frac multiple zones in a single operation. Multiple zones in one well can be individually isolated, fractured and flowed back simultaneously which results in reduced exposure to kill fluids and therefore higher retained conductivity for newly created fractures. The technique has been named CoilFRAC{trademark} by Dowell. The key benefits to the entire operation are reduced rig and operations time compared to conventional fracturing processes. Time savings, increased production, and environmental benefits are the economic drivers that result in rapid return on investment for production operators. The single trip concept for perforating and stimulation crews also brings additional benefits over multiple mobilizations. Wells which previously had only major zones perforated and stimulated and which are currently depleted can be revived economically using this system, giving the well a second life. The paper describes the equipment and its safety and contingency features, optimized shallow gas production in Alberta, and results from a South Texas oil well fracturing.

  12. Characterization and application of microearthquake clusters to problems of scaling, fault zone dynamics, and seismic monitoring at Parkfield, California

    SciTech Connect (OSTI)

    Nadeau, R.M.

    1995-10-01

    This document contains information about the characterization and application of microearthquake clusters and fault zone dynamics. Topics discussed include: Seismological studies; fault-zone dynamics; periodic recurrence; scaling of microearthquakes to large earthquakes; implications of fault mechanics and seismic hazards; and wave propagation and temporal changes.

  13. Insights From Laboratory Experiments On Simulated Faults With Application To Fracture Evolution In Geothermal Systems

    SciTech Connect (OSTI)

    Stephen L. Karner, Ph.D

    2006-06-01

    Laboratory experiments provide a wealth of information related to mechanics of fracture initiation, fracture propagation processes, factors influencing fault strength, and spatio-temporal evolution of fracture properties. Much of the existing literature reports on laboratory studies involving a coupling of thermal, hydraulic, mechanical, and/or chemical processes. As these processes operate within subsurface environments exploited for their energy resource, laboratory results provide insights into factors influencing the mechanical and hydraulic properties of geothermal systems. I report on laboratory observations of strength and fluid transport properties during deformation of simulated faults. The results show systematic trends that vary with stress state, deformation rate, thermal conditions, fluid content, and rock composition. When related to geophysical and geologic measurements obtained from engineered geothermal systems (e.g. microseismicity, wellbore studies, tracer analysis), laboratory results provide a means by which the evolving thermal reservoir can be interpreted in terms of physico-chemical processes. For example, estimates of energy release and microearthquake locations from seismic moment tensor analysis can be related to strength variations observed from friction experiments. Such correlations between laboratory and field data allow for better interpretations about the evolving mechanical and fluid transport properties in the geothermal reservoir ultimately leading to improvements in managing the resource.

  14. Development of Hydrologic Characterization Technology of Fault Zones -- Phase I, 2nd Report

    SciTech Connect (OSTI)

    Karasaki, Kenzi; Onishi, Tiemi; Black, Bill; Biraud, Sebastien

    2009-03-31

    This is the year-end report of the 2nd year of the NUMO-LBNL collaborative project: Development of Hydrologic Characterization Technology of Fault Zones under NUMO-DOE/LBNL collaboration agreement, the task description of which can be found in the Appendix 3. Literature survey of published information on the relationship between geologic and hydrologic characteristics of faults was conducted. The survey concluded that it may be possible to classify faults by indicators based on various geometric and geologic attributes that may indirectly relate to the hydrologic property of faults. Analysis of existing information on the Wildcat Fault and its surrounding geology was performed. The Wildcat Fault is thought to be a strike-slip fault with a thrust component that runs along the eastern boundary of the Lawrence Berkeley National Laboratory. It is believed to be part of the Hayward Fault system but is considered inactive. Three trenches were excavated at carefully selected locations mainly based on the information from the past investigative work inside the LBNL property. At least one fault was encountered in all three trenches. Detailed trench mapping was conducted by CRIEPI (Central Research Institute for Electric Power Industries) and LBNL scientists. Some intriguing and puzzling discoveries were made that may contradict with the published work in the past. Predictions are made regarding the hydrologic property of the Wildcat Fault based on the analysis of fault structure. Preliminary conceptual models of the Wildcat Fault were proposed. The Wildcat Fault appears to have multiple splays and some low angled faults may be part of the flower structure. In parallel, surface geophysical investigations were conducted using electrical resistivity survey and seismic reflection profiling along three lines on the north and south of the LBNL site. Because of the steep terrain, it was difficult to find optimum locations for survey lines as it is desirable for them to be as straight as possible. One interpretation suggests that the Wildcat Fault is westerly dipping. This could imply that the Wildcat Fault may merge with the Hayward Fault at depth. However, due to the complex geology of the Berkeley Hills, multiple interpretations of the geophysical surveys are possible. iv An effort to construct a 3D GIS model is under way. The model will be used not so much for visualization of the existing data because only surface data are available thus far, but to conduct investigation of possible abutment relations of the buried formations offset by the fault. A 3D model would be useful to conduct 'what if' scenario testing to aid the selection of borehole drilling locations and configurations. Based on the information available thus far, a preliminary plan for borehole drilling is outlined. The basic strategy is to first drill boreholes on both sides of the fault without penetrating it. Borehole tests will be conducted in these boreholes to estimate the property of the fault. Possibly a slanted borehole will be drilled later to intersect the fault to confirm the findings from the boreholes that do not intersect the fault. Finally, the lessons learned from conducting the trenching and geophysical surveys are listed. It is believed that these lessons will be invaluable information for NUMO when it conducts preliminary investigations at yet-to-be selected candidate sites in Japan.

  15. Directly imaging steeply-dipping fault zones in geothermal fields with multicomponent seismic data

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Chen, Ting; Huang, Lianjie

    2015-07-30

    For characterizing geothermal systems, it is important to have clear images of steeply-dipping fault zones because they may confine the boundaries of geothermal reservoirs and influence hydrothermal flow. Elastic reverse-time migration (ERTM) is the most promising tool for subsurface imaging with multicomponent seismic data. However, conventional ERTM usually generates significant artifacts caused by the cross correlation of undesired wavefields and the polarity reversal of shear waves. In addition, it is difficult for conventional ERTM to directly image steeply-dipping fault zones. We develop a new ERTM imaging method in this paper to reduce these artifacts and directly image steeply-dipping fault zones.more » In our new ERTM method, forward-propagated source wavefields and backward-propagated receiver wavefields are decomposed into compressional (P) and shear (S) components. Furthermore, each component of these wavefields is separated into left- and right-going, or downgoing and upgoing waves. The cross correlation imaging condition is applied to the separated wavefields along opposite propagation directions. For converted waves (P-to-S or S-to-P), the polarity correction is applied to the separated wavefields based on the analysis of Poynting vectors. Numerical imaging examples of synthetic seismic data demonstrate that our new ERTM method produces high-resolution images of steeply-dipping fault zones.« less

  16. Alleghanian development of the Goat Rock fault zone, southernmost Appalachians: Temporal compatibility with the master decollement

    SciTech Connect (OSTI)

    Steltenpohl, M.G. (Auburn Univ., AL (United States)); Goldberg, S.A. (Univ. of North Carolina, Chapel Hill (United States)); Hanley, T.B. (Columbus College, GA (United States)); Kunk, M.J. (Geological Survey, Reston, VA (United States))

    1992-09-01

    The Goat Rock and associated Bartletts Ferry fault zones, which mark the eastern margin of the Pine Mountain Grenville basement massif, are controversial due to the suggestion that they are rare exposed segments of the late Paleozoic southern Appalachian master decollement. The controversy in part stems from reported middle Paleozoic (Acadian) radiometric dates postulated as the time of movement along these fault zones. Ultramylonite samples from the type area at Goat Rock Dam yield a 287 [plus minus] 15 Ma Rb-Sr isochron interpreted as the time of Sr isotopic rehomgenization during mylonitization. This date is corroborated by Late Pennsylvanian-Early Permian [sup 40]Ar/[sup 39]Ar mineral ages on hornblende (297-288 Ma) and muscovite (285-278 Ma) from neomineralized and dynamically recrystallized rocks within and straddling the fault zone. These Late Pennsylvanian-Early Permian dates indicate the time of right-slip movement (Alleghenian) along the Goat Rock fault zone, which is compatible with the timing suggested by COCORP for thrusting along the southern Appalachian master decollement.

  17. Directly imaging steeply-dipping fault zones in geothermal fields with multicomponent seismic data

    SciTech Connect (OSTI)

    Chen, Ting; Huang, Lianjie

    2015-07-30

    For characterizing geothermal systems, it is important to have clear images of steeply-dipping fault zones because they may confine the boundaries of geothermal reservoirs and influence hydrothermal flow. Elastic reverse-time migration (ERTM) is the most promising tool for subsurface imaging with multicomponent seismic data. However, conventional ERTM usually generates significant artifacts caused by the cross correlation of undesired wavefields and the polarity reversal of shear waves. In addition, it is difficult for conventional ERTM to directly image steeply-dipping fault zones. We develop a new ERTM imaging method in this paper to reduce these artifacts and directly image steeply-dipping fault zones. In our new ERTM method, forward-propagated source wavefields and backward-propagated receiver wavefields are decomposed into compressional (P) and shear (S) components. Furthermore, each component of these wavefields is separated into left- and right-going, or downgoing and upgoing waves. The cross correlation imaging condition is applied to the separated wavefields along opposite propagation directions. For converted waves (P-to-S or S-to-P), the polarity correction is applied to the separated wavefields based on the analysis of Poynting vectors. Numerical imaging examples of synthetic seismic data demonstrate that our new ERTM method produces high-resolution images of steeply-dipping fault zones.

  18. Prediction of subsurface fracture in mining zone of Papua using passive seismic tomography based on Fresnel zone

    SciTech Connect (OSTI)

    Setiadi, Herlan; Nurhandoko, Bagus Endar B.; Wely, Woen; Riyanto, Erwin

    2015-04-16

    Fracture prediction in a block cave of underground mine is very important to monitor the structure of the fracture that can be harmful to the mining activities. Many methods can be used to obtain such information, such as TDR (Time Domain Relectometry) and open hole. Both of them have limitations in range measurement. Passive seismic tomography is one of the subsurface imaging method. It has advantage in terms of measurements, cost, and rich of rock physical information. This passive seismic tomography studies using Fresnel zone to model the wavepath by using frequency parameter. Fresnel zone was developed by Nurhandoko in 2000. The result of this study is tomography of P and S wave velocity which can predict position of fracture. The study also attempted to use sum of the wavefronts to obtain position and time of seismic event occurence. Fresnel zone tomography and the summation wavefront can predict location of geological structure of mine area as well.

  19. Variation in sericite composition from fracture zones within...

    Open Energy Info (EERE)

    found in drillhole samples within the geothermal system at Coso Hot Springs. Low-permeability zones of the crystalline basement contain coarse-grained relict muscovite, whereas...

  20. Heterogeneous slip and rupture models of the San Andreas fault zone based upon three-dimensional earthquake tomography

    SciTech Connect (OSTI)

    Foxall, W.

    1992-11-01

    Crystal fault zones exhibit spatially heterogeneous slip behavior at all scales, slip being partitioned between stable frictional sliding, or fault creep, and unstable earthquake rupture. An understanding the mechanisms underlying slip segmentation is fundamental to research into fault dynamics and the physics of earthquake generation. This thesis investigates the influence that large-scale along-strike heterogeneity in fault zone lithology has on slip segmentation. Large-scale transitions from the stable block sliding of the Central 4D Creeping Section of the San Andreas, fault to the locked 1906 and 1857 earthquake segments takes place along the Loma Prieta and Parkfield sections of the fault, respectively, the transitions being accomplished in part by the generation of earthquakes in the magnitude range 6 (Parkfield) to 7 (Loma Prieta). Information on sub-surface lithology interpreted from the Loma Prieta and Parkfield three-dimensional crustal velocity models computed by Michelini (1991) is integrated with information on slip behavior provided by the distributions of earthquakes located using, the three-dimensional models and by surface creep data to study the relationships between large-scale lithological heterogeneity and slip segmentation along these two sections of the fault zone.

  1. Parallel, Multigrid Finite Element Simulator for Fractured/Faulted and Other Complex Reservoirs based on Common Component Architecture (CCA)

    SciTech Connect (OSTI)

    Milind Deo; Chung-Kan Huang; Huabing Wang

    2008-08-31

    Black-oil, compositional and thermal simulators have been developed to address different physical processes in reservoir simulation. A number of different types of discretization methods have also been proposed to address issues related to representing the complex reservoir geometry. These methods are more significant for fractured reservoirs where the geometry can be particularly challenging. In this project, a general modular framework for reservoir simulation was developed, wherein the physical models were efficiently decoupled from the discretization methods. This made it possible to couple any discretization method with different physical models. Oil characterization methods are becoming increasingly sophisticated, and it is possible to construct geologically constrained models of faulted/fractured reservoirs. Discrete Fracture Network (DFN) simulation provides the option of performing multiphase calculations on spatially explicit, geologically feasible fracture sets. Multiphase DFN simulations of and sensitivity studies on a wide variety of fracture networks created using fracture creation/simulation programs was undertaken in the first part of this project. This involved creating interfaces to seamlessly convert the fracture characterization information into simulator input, grid the complex geometry, perform the simulations, and analyze and visualize results. Benchmarking and comparison with conventional simulators was also a component of this work. After demonstration of the fact that multiphase simulations can be carried out on complex fracture networks, quantitative effects of the heterogeneity of fracture properties were evaluated. Reservoirs are populated with fractures of several different scales and properties. A multiscale fracture modeling study was undertaken and the effects of heterogeneity and storage on water displacement dynamics in fractured basements were investigated. In gravity-dominated systems, more oil could be recovered at a given pore volume of injection at lower rates. However, if oil production can be continued at high water cuts, the discounted cumulative production usually favors higher production rates. The workflow developed during the project was also used to perform multiphase simulations in heterogeneous, fracture-matrix systems. Compositional and thermal-compositional simulators were developed for fractured reservoirs using the generalized framework. The thermal-compositional simulator was based on a novel 'equation-alignment' approach that helped choose the correct variables to solve depending on the number of phases present and the prescribed component partitioning. The simulators were used in steamflooding and in insitu combustion applications. The framework was constructed to be inherently parallel. The partitioning routines employed in the framework allowed generalized partitioning on highly complex fractured reservoirs and in instances when wells (incorporated in these models as line sources) were divided between two or more processors.

  2. Locating an active fault zone in Coso geothermal field by analyzing...

    Open Energy Info (EERE)

    waves from microearthquake data Abstract Active fault systems usually provide high-permeability channels for hydrothermal outflow in geothermal fields. Locating such fault systems...

  3. Area balance and strain in an extensional fault system: Strategies for improved oil recovery in fractured chalk, Gilbertown Field, southwestern Alabama. Annual report, March 1996--March 1997

    SciTech Connect (OSTI)

    Pashin, J.C.; Raymond, D.E.; Rindsberg, A.K.; Alabi, G.G.; Groshong, R.H.

    1997-08-01

    Gilbertown Field is the oldest oil field in Alabama and produces oil from chalk of the Upper Cretaceous Selma Group and from sandstone of the Eutaw Formation along the southern margin of the Gilbertown fault system. Most of the field has been in primary recovery since establishment, but production has declined to marginally economic levels. This investigation applies advanced geologic concepts designed to aid implementation of improved recovery programs. The Gilbertown fault system is detached at the base of Jurassic salt. The fault system began forming as a half graben and evolved in to a full graben by the Late Cretaceous. Conventional trapping mechanisms are effective in Eutaw sandstone, whereas oil in Selma chalk is trapped in faults and fault-related fractures. Burial modeling establishes that the subsidence history of the Gilbertown area is typical of extensional basins and includes a major component of sediment loading and compaction. Surface mapping and fracture analysis indicate that faults offset strata as young as Miocene and that joints may be related to regional uplift postdating fault movement. Preliminary balanced structural models of the Gilbertown fault system indicate that synsedimentary growth factors need to be incorporated into the basic equations of area balance to model strain and predict fractures in Selma and Eutaw reservoirs.

  4. Joint seismic, hydrogeological, and geomechanical investigations of a fracture zone in the Grimsel Rock Laboratory, Switzerland

    SciTech Connect (OSTI)

    Majer, E.L.; Myer, L.R.; Peterson, J.E. Jr.; Karasaki, K.; Long, J.C.S.; Martel, S.J. ); Bluemling, P.; Vomvoris, S. )

    1990-06-01

    This report is one of a series documenting the results of the Nagra-DOE Cooperative (NDC-I) research program in which the cooperating scientists explore the geological, geophysical, hydrological, geochemical, and structural effects anticipated from the use of a rock mass as a geologic repository for nuclear waste. From 1987 to 1989 the United States Department of Energy (DOE) and the Swiss Cooperative for the Storage of Nuclear Waste (Nagra) participated in an agreement to carryout experiments for understanding the effect of fractures in the storage and disposal of nuclear waste. As part of this joint work field and laboratory experiments were conducted at a controlled site in the Nagra underground Grimsel test site in Switzerland. The primary goal of these experiments in this fractured granite was to determine the fundamental nature of the propagation of seismic waves in fractured media, and to relate the seismological parameters to the hydrological parameters. The work is ultimately aimed at the characterization and monitoring of subsurface sites for the storage of nuclear waste. The seismic experiments utilizes high frequency (1000 to 10,000 Hertz) signals in a cross-hole configuration at scales of several tens of meters. Two-, three-, and four-sided tomographic images of the fractures and geologic structure were produced from over 60,000 raypaths through a 10 by 21 meter region bounded by two nearly horizontal boreholes and two tunnels. Intersecting this region was a dominant fracture zone which was the target of the investigations. In addition to these controlled seismic imaging experiments, laboratory work using core from this region were studied for the relation between fracture content, saturation, and seismic velocity and attenuation. In-situ geomechanical and hydrologic tests were carried out to determine the mechanical stiffness and conductivity of the fractures. 20 refs., 90 figs., 6 tabs.

  5. Geomechanical effects on CO{sub 2} leakage through fault zones during large-scale underground injection

    SciTech Connect (OSTI)

    Rinaldi, A.P.; Rutqvist, J.; Cappa, F.

    2013-09-01

    The importance of geomechanicsincluding the potential for faults to reactivate during large scale geologic carbon sequestration operationshas recently become more widely recognized. However, notwithstanding the potential for triggering notable (felt) seismic events, the potential for buoyancy-driven CO{sub 2} to reach potable groundwater and the ground surface is actually more important from public safety and storage-efficiency perspectives. In this context, this work extends the previous studies on the geomechanical modeling of fault responses during underground carbon dioxide injection, focusing on the short-term integrity of the sealing caprock, and hence on the potential for leakage of either brine or CO{sub 2} to reach the shallow groundwater aquifers during active injection. We consider stress/strain-dependent permeability and study the leakage through the fault zone as its permeability changes during a reactivation, also causing seismicity. We analyze several scenarios related to the volume of CO{sub 2} injected (and hence as a function of the overpressure), involving both minor and major faults, and analyze the profile risks of leakage for different stress/strain-permeability coupling functions. We conclude that whereas it is very difficult to predict how much fault permeability could change upon reactivation, this process can have a significant impact on the leakage rate. Moreover, our analysis shows that induced seismicity associated with fault reactivation may not necessarily open up a new flow path for leakage. Results show a poor correlation between magnitude and amount of fluid leakage, meaning that a single event is generally not enough to substantially change the permeability along the entire fault length. Consequently, even if some changes in permeability occur, this does not mean that the CO{sub 2} will migrate up along the entire fault, breaking through the caprock to enter the overlying aquifer.

  6. Pull-Apart in Strike-Slip Fault Zone | Open Energy Information

    Open Energy Info (EERE)

    of sinistral fault systems, resulting in localized crustal extension and enhanced permeability. Other definitions:Wikipedia Reegle Controlling Structures List of controlling...

  7. Method development and strategy for the characterization of complexly faulted and fractured rhyolitic tuffs, Yucca Mountain, Nevada

    SciTech Connect (OSTI)

    Karasaki, K.; Galloway, D.

    1991-06-01

    The planned high-level nuclear waste repository at Yucca Mountain, Nevada, would exist in unsaturated, fractured welded tuff. One possible contaminant pathway to the accessible environment is transport by groundwater infiltrating to the water table and flowing through the saturated zone. Therefore, an effort to characterize the hydrology of the saturated zone is being undertaken in parallel with that of the unsaturated zone. As a part of the saturated zone investigation, there wells-UE-25c{number_sign}1, UE-25c{number_sign}2, and UE-25c{number_sign}3 (hereafter called the c-holes)-were drilled to study hydraulic and transport properties of rock formations underlying the planned waste repository. The location of the c-holes is such that the formations penetrated in the unsaturated zone occur at similar depths and with similar thicknesses as at the planned repository site. In characterizing a highly heterogeneous flow system, several issues emerge. (1) The characterization strategy should allow for the virtual impossibility to enumerate and characterize all heterogeneities. (2) The methodology to characterize the heterogeneous flow system at the scale of the well tests needs to be established. (3) Tools need to be developed for scaling up the information obtained at the well-test scale to the larger scale of the site. In the present paper, the characterization strategy and the methods under development are discussed with the focus on the design and analysis of the field experiments at the c-holes.

  8. Modeling fault-zone guided waves of microearthquakes in a geothermal...

    Open Energy Info (EERE)

    velocity structure have been estimated. It is suggested here that the identification and modeling of such guided waves is an effective tool to locate fracture-induced,...

  9. Fracture initiation by local brittle zones in weldments of quenched and tempered structural alloy steel plate

    SciTech Connect (OSTI)

    Kenney, K.L.; Reuter, W.G.; Reemsnyder, H.S.; Matlock, D.K.

    1997-12-31

    The heat-affected zone (HAZ) embrittlement of an API 2Y Grade 50T quenched and tempered offshore structural steel plate, welded by the submerged-arc process at a heat input of 4.5 kJ/mm, was investigated from the viewpoint of identifying the local brittle zone (LBZ) microstructure and the metallurgical factors associated with its formation. Microstructural and fractographic analysis showed the LBZ microstructure to be dual phase martensite-austenite (M-A) constituent. The formation of M-A constituent was found to be related to microstructural banding of the hot-rolled base plate. When the banded base plate was welded, M-A constituent formed only within the band microstructure which penetrated the intercritically-reheated coarse-grain HAZ (IRCGHAZ). The chemistry of the band microstructure in conjunction with the thermal cycle of the IRCGHAZ provided the critical conditions for the formation of M-A constituent in the API 2Y Grade 50T steel investigated. The influence of local brittle zones (i.e., M-A constituent) on the HAZ fracture toughness was evaluated by means of Crack-Tip Opening Displacement (CTOD) tests. These tests showed the steel to suffer embrittlement when the fatigue precrack sampled an intercritically-reheated coarse-grain HAZ which contained M-A constituent, confirming that M-A constituent is the major microstructural factor controlling the HAZ toughness of this particular steel.

  10. Significance of recurrent fault movement at Grays Point quarry, southeast Missouri

    SciTech Connect (OSTI)

    Diehl, S.F.; Throckmorton, C.K. ); Clendenin, C.W. )

    1993-03-01

    Geologic relationships indicate recurrent movement on a fault exposed at Grays Point, MO. Faulting offsets Middle-Late Ordovician Plattin Group, Decorah Group, Kimmswick Limestone, and Maquoketa Group strata. In plan, the fault is characterized by a relatively narrow zone (30--70 m) of northeast-striking fault slices associated with a northwest-striking zone of right-stepping en echelon fractures. This systematic fracture-fault array identifies right-lateral strike-slip movement. A vertically offset basal Decorah Group contact shows 22 m of down-to-the-southeast dip slip, which indicates a component of oblique slip. Oldest recognizable movement on the fault is evidenced by Maquoketa Group strata that fill a northeast-striking, wedge-shaped synform. Post-Ordovician movement along an adjacent subvertical fault displaces part of this synform 300 m right laterally. In thin section, the northwest-striking fracture set shows a polyphase history of deformation indicated by cataclastic textures and intrusion of carbonate-rich fluids. Three periods of movement occurred: (1) initial fracturing sealed by authigenic mineral cements; (2) renewed fracturing associated with recrystallization of sub-rounded clasts; and (3) subsequent brecciation marked by angular clasts and filling of fractures and vugs. Each successive fluid intrusion is characterized by an increase in grain size of the authigenic cement. The fault is subparallel to the regional, northeast-striking English Hill fault system. Polyphase oblique-slip deformation suggests that the fault, like others in southeastern Missouri, is a reactivated Late Proterozoic-Cambrian zone of weakness. Initial fault reactivation occurred during Middle-Late Ordovician as opposed to Devonian, as commonly interpreted for southeast Missouri. Multiple authigenic mineral cements imply that fluids may have been an important factor influencing the fault's tendency to be reactivated.

  11. Reservoir-scale fracture permeability in the Dixie Valley, Nevada, geothermal field

    SciTech Connect (OSTI)

    Barton, C.A.; Zoback, M.D.; Hickman, S.; Morin, R.; Benoit, D.

    1998-08-01

    Wellbore image data recorded in six wells penetrating a geothermal reservoir associated with an active normal fault at Dixie Valley, Nevada, were used in conjunction with hydrologic tests and in situ stress measurements to investigate the relationship between reservoir productivity and the contemporary in situ stress field. The analysis of data from wells drilled into productive and non-productive segments of the Stillwater fault zone indicates that fractures must be both optimally oriented and critically stressed to have high measured permeabilities. Fracture permeability in all wells is dominated by a relatively small number of fractures oriented parallel to the local trend of the Stillwater Fault. Fracture geometry may also play a significant role in reservoir productivity. The well-developed populations of low angle fractures present in wells drilled into the producing segment of the fault are not present in the zone where production is not commercially viable.

  12. Analysis of the hydraulic data from the MI fracture zone at the Grimsel Rock Laboratory, Switzerland

    SciTech Connect (OSTI)

    Davey, A.; Karasaki, K.; Long, J.C.S.; Landsfeld, M.; Mensch, A.; Martel, S.J.

    1989-10-01

    One of the major problems in analyzing flow and transport in fractured rock is that the flow may be largely confined to a poorly connected network of fractures. In order to overcome some of this problem, Lawrence Berkeley Laboratory (LBL) has been developing a new type of fracture hydrology model called an equivalent discontinuum model. In this model the authors represent the discontinuous nature of the problem through flow on a partially filled lattice. A key component in constructing an equivalent discontinuum model from this lattice is removing some of the conductive elements such that the system is partially connected in the same manner as the fracture network. This is done through a statistical inverse technique called simulated annealing. The fracture network model is annealed by continually modifying a base model, or template such that the modified systems behave more and more like the observed system. In order to see how the simulated annealing algorithm works, the authors have developed a series of synthetic real cases. In these cases, the real system is completely known so that the results of annealing to steady state data can be evaluated absolutely. The effect of the starting configuration has been studied by varying the percent of conducting elements in the initial configuration. Results have shown that the final configurations converge to about the same percentage of conducting elements. An example using Nagra field data from the Migration Experiment (MI) at Grimsel Rock Laboratory in Switzerland is also analyzed. 24 refs., 33 figs., 3 tabs.

  13. Integrating 3D seismic curvature and curvature gradient attributes for fracture characterization: Methodologies and interpretational implications

    SciTech Connect (OSTI)

    Gao, Dengliang

    2013-03-01

    In 3D seismic interpretation, curvature is a popular attribute that depicts the geometry of seismic reflectors and has been widely used to detect faults in the subsurface; however, it provides only part of the solutions to subsurface structure analysis. This study extends the curvature algorithm to a new curvature gradient algorithm, and integrates both algorithms for fracture detection using a 3D seismic test data set over Teapot Dome (Wyoming). In fractured reservoirs at Teapot Dome known to be formed by tectonic folding and faulting, curvature helps define the crestal portion of the reservoirs that is associated with strong seismic amplitude and high oil productivity. In contrast, curvature gradient helps better define the regional northwest-trending and the cross-regional northeast-trending lineaments that are associated with weak seismic amplitude and low oil productivity. In concert with previous reports from image logs, cores, and outcrops, the current study based on an integrated seismic curvature and curvature gradient analysis suggests that curvature might help define areas of enhanced potential to form tensile fractures, whereas curvature gradient might help define zones of enhanced potential to develop shear fractures. In certain fractured reservoirs such as at Teapot Dome where faulting and fault-related folding contribute dominantly to the formation and evolution of fractures, curvature and curvature gradient attributes can be potentially applied to differentiate fracture mode, to predict fracture intensity and orientation, to detect fracture volume and connectivity, and to model fracture networks.

  14. Structural geology of the French Peak accommodation zone, Nevada Test Site, southwestern Nevada

    SciTech Connect (OSTI)

    Hudson, M.R.

    1997-12-31

    The French Peak accommodation zone (FPAZ) forms an east-trending bedrock structural high in the Nevada Test Site region of southwestern Nevada that formed during Cenozoic Basin and Range extension. The zone separates areas of opposing directions of tilt and downthrow on faults in the Yucca Flat and Frenchman Flat areas. Paleomagnetic data show that rocks within the accommodation zone adjacent to Yucca Flat were not strongly affected by vertical-axis rotation and thus that the transverse strikes of fault and strata formed near their present orientation. Both normal- and oblique strike-slip faulting in the FPAZ largely occurred under a normal-fault stress regime, with least principal stress oriented west-northwest. The normal and sinistral faults in the Puddle Peka segment transfers extension between the Plutonium Valley normal fault zone and the Cane Spring sinistral fault. Recognition of sinistral shear across the Puddle Peak segment allows the Frenchman Flat basin to be interpreted as an asymmetric pull-apart basin developed between the FPAZ and a zone of east-northeast-striking faults to the south that include the Rock Valley fault. The FPAZ has the potential to influence ground-water flow in the region in several ways. Fracture density and thus probably fracture conductivity is high within the FPAZ due to the abundant fault splays present. Moreover,, fractures oriented transversely to the general southward flow of ground water through Yucca Flat area are significant and have potential to laterally divert ground water. Finally, the FPAZ forms a faulted structural high whose northern and southern flanks may permit intermixing of ground waters from different aquifer levels, namely the lower carbonate, welded tuff, and alluvial aquifers. 42 refs.

  15. Fracture Permeability and in Situ Stress in the Dixie Valley, Nevada, Geothermal Reservoir

    SciTech Connect (OSTI)

    M. D. Zoback

    1999-03-08

    We have collected and analyzed fracture and fluid flow data from wells both within and outside the producing geothermal reservoir at Dixie Valley. Data from wellbore imaging and flow tests in wells outside the producing field that are not sufficiently hydraulically connected to the reservoir to be of commercial value provide both the necessary control group of fracture populations and an opportunity to test the concepts proposed in this study on a regional, whole-reservoir scale. Results of our analysis indicate that fracture zones with high measured permeabilities within the producing segment of the fault are parallel to the local trend of the Stillwater fault and are optimally oriented and critically stressed for frictional failure in the overall east-southeast extensional stress regime measured at the site. In contrast, in the non-producing (i.e., relatively impermeable:) well 66-21 the higher ratio of S{sub hmin} to S{sub v} acts to decrease the shear stress available to drive fault slip. Thus, although many of the fractures at this site (like the Stillwater fault itself) are optimally oriented for normal faulting they are not critically stressed for frictional failure. Although some of the fractures observed in the non-producing well 45-14 are critically stressed for frictional failure, the Stillwater fault zone itself is frictionally stable. Thus, the high horizontal differential stress (i.e., S{sub Hmax}-S{sub hmin}) together with the severe misorientation of the Stillwater fault zone for normal faulting at this location appear to dominate the overall potential for fluid flow.

  16. Tectonic controls on fracture permeability in a geothermal reservoir at Dixie Valley, Nevada

    SciTech Connect (OSTI)

    Hickman, S.; Zoback, M.

    1998-08-01

    To help determine the nature and origins of permeability variations within a fault-hosted geothermal reservoir at Dixie Valley, Nevada, the authors conducted borehole televiewer logging and hydraulic fracturing stress measurements in six wells drilled into the Stillwater fault zone at depths of 2--3 km. Televiewer logs from wells penetrating the highly permeable portion of the fault zone revealed extensive drilling-induced tensile fractures. As the Stillwater fault at this location dips S45{degree}E at {approximately} 53{degree} it is nearly at the optimal orientation for normal faulting in the current stress field. Hydraulic fracturing tests from these permeable wells show that the magnitude of S{sub hmin} is very low relative to the vertical stress S{sub v}. Similar measurements conducted in two wells penetrating a relatively impermeable segment of the Stillwater fault zone 8 and 20 km southwest of the producing geothermal reservoir indicate that the orientation of S{sub hmin} is S20{degree}E and S41{degree}E, respectively, with S{sub hmin}/S{sub v} ranging from 0.55--0.64 at depths of 1.9--2.2 km. This stress orientation is near optimal for normal faulting on the Stillwater fault in the northernmost non-producing well, but {approximately} 40{degree} rotated from the optimal orientation for normal faulting in the southernmost well. The observation that borehole breakouts were present in these nonproducing wells, but absent in wells drilled into the permeable main reservoir, indicates a significant increase in the magnitude of maximum horizontal principal stress, S{sub Hmax}, in going from the producing to non-producing segments of the fault. The increase in S{sub Hmaz}, coupled with elevated S{sub hmin}/S{sub v} values and a misorientation of the Stillwater fault zone with respect to the principal stress directions, leads to a decrease in the proximity of the fault zone to Coulomb failure. This suggests that a necessary condition for high reservoir permeability is that the Stillwater fault zone be critically stressed for frictional failure in the current stress field.

  17. Effect of faulting on ground-water movement in the Death Valley region, Nevada and California

    SciTech Connect (OSTI)

    Faunt, C.C.

    1997-12-31

    This study characterizes the hydrogeologic system of the Death Valley region, an area covering approximately 100,000 square kilometers. The study also characterizes the effects of faults on ground-water movement in the Death Valley region by synthesizing crustal stress, fracture mechanics,a nd structural geologic data. The geologic conditions are typical of the Basin and Range Province; a variety of sedimentary and igneous intrusive and extrusive rocks have been subjected to both compressional and extensional deformation. Faulting and associated fracturing is pervasive and greatly affects ground-water flow patterns. Faults may become preferred conduits or barriers to flow depending on whether they are in relative tension, compression, or shear and other factors such as the degree of dislocations of geologic units caused by faulting, the rock types involved, the fault zone materials, and the depth below the surface. The current crustal stress field was combined with fault orientations to predict potential effects of faults on the regional ground-water flow regime. Numerous examples of fault-controlled ground-water flow exist within the study area. Hydrologic data provided an independent method for checking some of the assumptions concerning preferential flow paths. 97 refs., 20 figs., 5 tabs.

  18. Reservoir fracture mapping using microearthquakes: Austin chalk, Giddings field, TX and 76 field, Clinton Co., KY

    SciTech Connect (OSTI)

    Phillips, W.S.; Rutledge, J.T.; Gardner, T.L.; Fairbanks, T.D.; Miller, M.E.; Schuessler, B.K.

    1996-11-01

    Patterns of microearthquakes detected downhole defined fracture orientation and extent in the Austin chalk, Giddings field, TX and the 76 field, Clinton Co., KY. We collected over 480 and 770 microearthquakes during hydraulic stimulation at two sites in the Austin chalk, and over 3200 during primary production in Clinton Co. Data were of high enough quality that 20%, 31% and 53% of the events could be located, respectively. Reflected waves constrained microearthquakes to the stimulated depths at the base of the Austin chalk. In plan view, microearthquakes defined elongate fracture zones extending from the stimulation wells parallel to the regional fracture trend. However, widths of the stimulated zones differed by a factor of five between the two Austin chalk sites, indicating a large difference in the population of ancillary fractures. Post-stimulation production was much higher from the wider zone. At Clinton Co., microearthquakes defined low-angle, reverse-fault fracture zones above and below a producing zone. Associations with depleted production intervals indicated the mapped fractures had been previously drained. Drilling showed that the fractures currently contain brine. The seismic behavior was consistent with poroelastic models that predicted slight increases in compressive stress above and below the drained volume.

  19. Fracture Characteristics in a Disposal Pit on Mesita del Buey, Los Alamos National Laboratory

    SciTech Connect (OSTI)

    David T. Vaniman; Steven L. Reneau

    1998-12-01

    The characteristics of fractures in unit 2 of the Tshirege Member of the Bandelier Tuff were documented in Pit 39, a newly excavated 13.7 m deep disposal pit at Material Disposal Area G on Mesita del Buey. The average spacing between fractures is about 1.0 to 1.3 m, the average fracture aperture is about 3 to 5 mm, and the average fracture dip is about 76o to 77o. Fracture spacing and dip in Pit 39 are generally consistent with that reported from other fracture studies on the Pajarito Plateau, although the fracture apertures in Pit 39 are less than reported elsewhere. Measured fracture orientations are strongly affected by biases imparted by the orientations of the pit walls, which, combined with a small data set, make identification of potential preferred orientations dlfflcult. The most prominent fracture orientations observed in Pit 39, about E-W and N20E, are often not well represented elsewhere on the Pajarito Plateau. Fracture fills contain smectite to about 3 m depth, and calcite and opal may occur at all depths, principally associated with roots or root fossils (rhizoliths). Roots of pifion pine extend in fractures to the bottom of the pit along the north side, perhaps indicating a zone of preferred infiltration of water. Finely powdered tuff with clay-sized particles occurs within a number of fractures and may record abrasive disaggregation associated with small amounts of displacement on minor local faults.

  20. Structural Settings Of Hydrothermal Outflow- Fracture Permeability...

    Open Energy Info (EERE)

    Settings Of Hydrothermal Outflow- Fracture Permeability Maintained By Fault Propagation And Interaction Jump to: navigation, search OpenEI Reference LibraryAdd to library Journal...

  1. Controls on Fault-Hosted Fluid Flow: Preliminary Results from...

    Open Energy Info (EERE)

    Flow: Preliminary Results from the Coso Geothermal Field, CA Abstract cap rock, permeability, fault, fracture, clay, Coso Authors Davatzes, N.C.; Hickman and S.H. Published...

  2. Modeling of fault reactivation and induced seismicity during...

    Office of Scientific and Technical Information (OSTI)

    of shale-gas reservoirs Citation Details In-Document Search Title: Modeling of fault reactivation and induced seismicity during hydraulic fracturing of shale-gas reservoirs ...

  3. Modeling of fault reactivation and induced seismicity during...

    Office of Scientific and Technical Information (OSTI)

    of shale-gas reservoirs Citation Details In-Document Search Title: Modeling of fault reactivation and induced seismicity during hydraulic fracturing of shale-gas reservoirs We ...

  4. Fault finder

    DOE Patents [OSTI]

    Bunch, Richard H. (1614 NW. 106th St., Vancouver, WA 98665)

    1986-01-01

    A fault finder for locating faults along a high voltage electrical transmission line. Real time monitoring of background noise and improved filtering of input signals is used to identify the occurrence of a fault. A fault is detected at both a master and remote unit spaced along the line. A master clock synchronizes operation of a similar clock at the remote unit. Both units include modulator and demodulator circuits for transmission of clock signals and data. All data is received at the master unit for processing to determine an accurate fault distance calculation.

  5. Uncertainty quantification for evaluating the impacts of fracture zone on pressure build-up and ground surface uplift during geological CO? sequestration

    SciTech Connect (OSTI)

    Bao, Jie; Hou, Zhangshuan; Fang, Yilin; Ren, Huiying; Lin, Guang

    2015-06-01

    A series of numerical test cases reflecting broad and realistic ranges of geological formation and preexisting fault properties was developed to systematically evaluate the impacts of preexisting faults on pressure buildup and ground surface uplift during CO? injection. Numerical test cases were conducted using a coupled hydro-geomechanical simulator, eSTOMP (extreme-scale Subsurface Transport over Multiple Phases). For efficient sensitivity analysis and reliable construction of a reduced-order model, a quasi-Monte Carlo sampling method was applied to effectively sample a high-dimensional input parameter space to explore uncertainties associated with hydrologic, geologic, and geomechanical properties. The uncertainty quantification results show that the impacts on geomechanical response from the pre-existing faults mainly depend on reservoir and fault permeability. When the fault permeability is two to three orders of magnitude smaller than the reservoir permeability, the fault can be considered as an impermeable block that resists fluid transport in the reservoir, which causes pressure increase near the fault. When the fault permeability is close to the reservoir permeability, or higher than 10?? m in this study, the fault can be considered as a conduit that penetrates the caprock, connecting the fluid flow between the reservoir and the upper rock.

  6. CHARACTERIZATION OF IN-SITU STRESS AND PERMEABILITY IN FRACTURED RESERVOIRS

    SciTech Connect (OSTI)

    Daniel R. Burns; M. Nafi Toksoz

    2005-08-01

    During the past six months we have adapted our 3-D elastic, anisotropic finite difference code by implementing the rotated staggered grid (RSG) method to more accurately represent large contrasts of elastic moduli between the fractures and surrounding formation, and applying the perfectly matched layer (PML) absorbing boundary condition to minimize boundary reflections. Two approaches for estimating fracture spacing from scattered seismic energy were developed. The first relates notches in the amplitude spectra of the scattered wavefield to the dominant fracture spacing that caused the scattering. The second uses conventional FK filtering to isolate the backscattered signals and then recovers an estimate of the fracture spacing from the dominant wavelength of those signals. Both methods were tested on synthetic data and then applied to the Emilio field data. The spectral notch method estimated the Emilio fracture spacing to be about 30 to 40 m, while the FK method found fracture spacing of about 48 to 53 m. We continue to work on two field data sets from fractured carbonate reservoirs provided by our industry sponsors--the offshore Emilio Field data (provided by ENIAGIP), and an onshore reservoir from the Middle East (provided by Shell). Calibration data in the form of well logs and previous fracture studies are available for both data sets. In previous reports we showed the spatial distribution fractures in the Emilio Field based on our calculated scattering index values. To improve these results we performed a map migration of all the scattering indices. The results of this migration process show a very strong correlation between the spatial distribution and orientation of our estimated fracture distribution and the fault system in the field. We observe that the scattering index clusters tend to congregate around the fault zones, particularly near multiple faults and at fault tips. We have also processed a swath of data from the second data set (the onshore carbonate field). FMI data are available from a number of wells for comparison to our seismic scattering analysis results. The agreement is very good, providing confidence that these methods can be applied to land seismic data that do not have the ideal azimuthal coverage.

  7. Detailed Geophysical Fault Characterization in Yucca Flat, Nevada Test Site, Nevada

    SciTech Connect (OSTI)

    Theodore H. Asch; Donald Sweetkind; Bethany L. Burton; Erin L. Wallin

    2009-02-10

    Yucca Flat is a topographic and structural basin in the northeastern part of the Nevada Test Site (NTS) in Nye County, Nevada. Between the years 1951 and 1992, 659 underground nuclear tests took place in Yucca Flat; most were conducted in large, vertical excavations that penetrated alluvium and the underlying Cenozoic volcanic rocks. Radioactive and other potential chemical contaminants at the NTS are the subject of a long-term program of investigation and remediation by the U.S. Department of Energy (DOE), National Nuclear Security Administration, Nevada Site Office, under its Environmental Restoration Program. As part of the program, the DOE seeks to assess the extent of contamination and to evaluate the potential risks to humans and the environment from byproducts of weapons testing. To accomplish this objective, the DOE Environmental Restoration Program is constructing and calibrating a ground-water flow model to predict hydrologic flow in Yucca Flat as part of an effort to quantify the subsurface hydrology of the Nevada Test Site. A necessary part of calibrating and evaluating a model of the flow system is an understanding of the location and characteristics of faults that may influence ground-water flow. In addition, knowledge of fault-zone architecture and physical properties is a fundamental component of the containment of the contamination from underground nuclear tests, should such testing ever resume at the Nevada Test Site. The goal of the present investigation is to develop a detailed understanding of the geometry and physical properties of fault zones in Yucca Flat. This study was designed to investigate faults in greater detail and to characterize fault geometry, the presence of fault splays, and the fault-zone width. Integrated geological and geophysical studies have been designed and implemented to work toward this goal. This report describes the geophysical surveys conducted near two drill holes in Yucca Flat, the data analyses performed, and the integrated interpretations developed from the suite of geophysical methodologies utilized in this investigation. Data collection for this activity started in the spring of 2005 and continued into 2006. A suite of electrical geophysical surveys were run in combination with ground magnetic surveys; these surveys resulted in high-resolution subsurface data that portray subsurface fault geometry at the two sites and have identified structures not readily apparent from surface geologic mapping, potential field geophysical data, or surface effects fracture maps.

  8. Geomechanical Simulation of Fluid-Driven Fractures

    SciTech Connect (OSTI)

    Makhnenko, R.; Nikolskiy, D.; Mogilevskaya, S.; Labuz, J.

    2012-11-30

    The project supported graduate students working on experimental and numerical modeling of rock fracture, with the following objectives: (a) perform laboratory testing of fluid-saturated rock; (b) develop predictive models for simulation of fracture; and (c) establish educational frameworks for geologic sequestration issues related to rock fracture. These objectives were achieved through (i) using a novel apparatus to produce faulting in a fluid-saturated rock; (ii) modeling fracture with a boundary element method; and (iii) developing curricula for training geoengineers in experimental mechanics, numerical modeling of fracture, and poroelasticity.

  9. Physiochemical Evidence of Faulting Processes and Modeling of Fluid in Evolving Fault Systems in Southern California

    SciTech Connect (OSTI)

    Boles, James

    2013-05-24

    Our study targets recent (Plio-Pleistocene) faults and young (Tertiary) petroleum fields in southern California. Faults include the Refugio Fault in the Transverse Ranges, the Ellwood Fault in the Santa Barbara Channel, and most recently the Newport- Inglewood in the Los Angeles Basin. Subsurface core and tubing scale samples, outcrop samples, well logs, reservoir properties, pore pressures, fluid compositions, and published structural-seismic sections have been used to characterize the tectonic/diagenetic history of the faults. As part of the effort to understand the diagenetic processes within these fault zones, we have studied analogous processes of rapid carbonate precipitation (scaling) in petroleum reservoir tubing and manmade tunnels. From this, we have identified geochemical signatures in carbonate that characterize rapid CO2 degassing. These data provide constraints for finite element models that predict fluid pressures, multiphase flow patterns, rates and patterns of deformation, subsurface temperatures and heat flow, and geochemistry associated with large fault systems.

  10. US Geological Survey Committee for the Advancement of Science in the Yucca Mountain Project symposium on {open_quotes}Fractures, Hydrology, and Yucca Mountain{close_quotes}: Abstracts and summary

    SciTech Connect (OSTI)

    Gomberg, J.

    1991-12-31

    The principal objective of this symposium is to review the available information on fractured/faulted terrains in terms of a coherent hydrogeologic model of ground-water fluid flow and transport, particularly as it pertains to the Yucca Mountain region. This review addresses the influence and significance of fractures on ground-water flow and the transport of conservative-species solutes within the context of the hydrogeologic setting of the Yucca Mountain area. The relations between fluid flow and fractured or faulted host rock are examined integrally from information on geologic, seismologic, hydrologic, and geomechanical properties of the system. The development of new hydrogeologic approaches that incorporate information from this integrated database are contrasted with more standard approaches toward understanding flow in fractured reservoirs. Ground-water flow in both the unsaturated zone and the saturated zone are considered. The application of various models of flow is addressed, examples include porous-media equivalent and discontinuum fracture-network models. Data and interpretations from the Yucca Mountain area are presented to establish a context for information exchange. The symposium includes discussions relevant to technical considerations for characterizing the Yucca Mountain area hydrogeology. On the basis of these discussions, CASY has compiled this document in order to formally summarize the proceedings and communicate recommendations for future directions of research and investigation.

  11. Observations on Faults and Associated Permeability Structures in Hydrogeologic Units at the Nevada Test Site

    SciTech Connect (OSTI)

    Prothro, Lance B.; Drellack, Sigmund L.; Haugstad, Dawn N.; Huckins-Gang, Heather E.; Townsend, Margaret J.

    2009-03-30

    Observational data on Nevada Test Site (NTS) faults were gathered from a variety of sources, including surface and tunnel exposures, core samples, geophysical logs, and down-hole cameras. These data show that NTS fault characteristics and fault zone permeability structures are similar to those of faults studied in other regions. Faults at the NTS form complex and heterogeneous fault zones with flow properties that vary in both space and time. Flow property variability within fault zones can be broken down into four major components that allow for the development of a simplified, first approximation model of NTS fault zones. This conceptual model can be used as a general guide during development and evaluation of groundwater flow and contaminate transport models at the NTS.

  12. Multi-Attribute Seismic/Rock Physics Approach to Characterizing Fractured Reservoirs

    SciTech Connect (OSTI)

    Gary Mavko

    2004-11-30

    Most current seismic methods to seismically characterize fractures in tight reservoirs depend on a few anisotropic wave propagation signatures that can arise from aligned fractures. While seismic anisotropy can be a powerful fracture diagnostic, a number of situations can lessen its usefulness or introduce interpretation ambiguities. Fortunately, laboratory and theoretical work in rock physics indicates that a much broader spectrum of fracture seismic signatures can occur, including a decrease in P- and S-wave velocities, a change in Poisson's ratio, an increase in velocity dispersion and wave attenuation, as well as well as indirect images of structural features that can control fracture occurrence. The goal of this project was to demonstrate a practical interpretation and integration strategy for detecting and characterizing natural fractures in rocks. The approach was to exploit as many sources of information as possible, and to use the principles of rock physics as the link among seismic, geologic, and log data. Since no single seismic attribute is a reliable fracture indicator in all situations, the focus was to develop a quantitative scheme for integrating the diverse sources of information. The integrated study incorporated three key elements: The first element was establishing prior constraints on fracture occurrence, based on laboratory data, previous field observations, and geologic patterns of fracturing. The geologic aspects include analysis of the stratigraphic, structural, and tectonic environments of the field sites. Field observations and geomechanical analysis indicates that fractures tend to occur in the more brittle facies, for example, in tight sands and carbonates. In contrast, strain in shale is more likely to be accommodated by ductile flow. Hence, prior knowledge of bed thickness and facies architecture, calibrated to outcrops, are powerful constraints on the interpreted fracture distribution. Another important constraint is that fracturing is likely to be more intense near faults--sometimes referred to as the damaged zone. Yet another constraint, based on world-wide observations, is that the maximum likely fracture density increases with depth in a well-defined way. Defining these prior constrains has several benefits: they lead to a priori probability distributions of fractures, that are important for objective statistical integration; they limit the number of geologic hypotheses that need to be theoretically modeled; they provide plausible models for fracture distributions below the seismic resolution. The second element was theoretical rock physics modeling of optimal seismic attributes, including offset and azimuth dependence of traveltime, amplitude, and impedance signatures of anisotropic fractured rocks. The suggested workflow is to begin with an elastic earth model, based on well logs, theoretically add fractures to the likely facies as defined by the geologic prior information, and then compute synthetic seismic traces and attributes, including variations in P and S-wave velocities, Poisson's ratio, reflectivity, travel time, attenuation, and anisotropies of these parameters. This workflow is done in a Monte-Carlo fashion, yielding ranges of expected fracture signatures, and allowing realistic assessments of uncertainty to be honored. The third element was statistical integration of the geophysical data and prior constraints to map fracture intensity and orientations, along with uncertainties. A Bayesian framework was developed that allowed systematic integration of the prior constraints, the theoretical relations between fractures and their seismic signatures, and the various observed seismic observations. The integration scheme was successfully applied on an East Texas field site. The primary benefit from the study was the optimization and refinement of practical workflows for improved geophysical characterization of natural fractures and for quantifying the uncertainty of these interpretations. By presenting a methodology for integrating various types of information, the workflow will

  13. Colorado Regional Faults

    SciTech Connect (OSTI)

    Hussein, Khalid

    2012-02-01

    Citation Information: Originator: Earth Science &Observation Center (ESOC), CIRES, University of Colorado at Boulder Originator: Colorado Geological Survey (CGS) Publication Date: 2012 Title: Regional Faults Edition: First Publication Information: Publication Place: Earth Science & Observation Center, Cooperative Institute for Research in Environmental Science, University of Colorado, Boulder Publisher: Earth Science &Observation Center (ESOC), CIRES, University of Colorado at Boulder Description: This layer contains the regional faults of Colorado Spatial Domain: Extent: Top: 4543192.100000 m Left: 144385.020000 m Right: 754585.020000 m Bottom: 4094592.100000 m Contact Information: Contact Organization: Earth Science &Observation Center (ESOC), CIRES, University of Colorado at Boulder Contact Person: Khalid Hussein Address: CIRES, Ekeley Building Earth Science & Observation Center (ESOC) 216 UCB City: Boulder State: CO Postal Code: 80309-0216 Country: USA Contact Telephone: 303-492-6782 Spatial Reference Information: Coordinate System: Universal Transverse Mercator (UTM) WGS’1984 Zone 13N False Easting: 500000.00000000 False Northing: 0.00000000 Central Meridian: -105.00000000 Scale Factor: 0.99960000 Latitude of Origin: 0.00000000 Linear Unit: Meter Datum: World Geodetic System 1984 (WGS ’984) Prime Meridian: Greenwich Angular Unit: Degree Digital Form: Format Name: Shape file

  14. GLORIA mosaic of the U. S. Hawaiian exclusive economic zone

    SciTech Connect (OSTI)

    Torresan, M.E. )

    1990-06-01

    Digital long-range side-scan sonar reconnaissance surveys using GLORIA have imaged about 65% of the nearly 2.4 million km{sup 2} of the Hawaiian EEZ. The images have been processed and compiled into one mosaic that comprises the EEZ area surrounding the principal Hawaiian islands (from Hawaii to Kauai); extending on the south side of the ridge west to Kure Island, and on the north side to St. Rogatien Bank. The GLORIA images depict a variety of features that include enormous slumps and debris avalanches, lava flows, seafloor spreading fabric, fracture zones, seamounts, and unusual sedimentation patterns with more detail than previously had been possible with typical seismic reflection techniques. Some of these features were unknown before the GLORIA surveys. In particular, the GLORIA images show that the major degradational processes that affect the island and ridge areas are massive, likely tsunamogenic, blocky debris avalanches and slumps. These failures mantle the flanks of the ridge; some extending across the trough and up on to the Hawaiian Arch (up to 230 km from their sources). Over 30 failures are identified, ranging in area from 250 to > 6,000 km{sup 2} and having volumes from 500 to > 5,000 km{sup 3}. Such deposits cover > 125,000 km{sup 3} of the Ridge and adjacent seafloor. Also imaged are large Cenozoic submarine volcanic flow fields situated on the Hawaiian Arch. One such field, the North Arch field, is located north of Oahu between the Molokai and Murray fracture zones, and covers about 200,000 km{sup 2}. Prior to the GLORIA imagery only a small portion of this flow field was mapped. In addition, the imagery depicts the finer details of the Molokai and Murray fracture zones, the Cretaceous seafloor spreading fabric, and tensional faults on the Hawaiian Arch.

  15. Area balance and strain in an extensional fault system: Strategies for improved oil recovery in fractured chalk, Gilbertown Field, southwestern Alabama -- Year 2. Annual report, March 1997--March 1998

    SciTech Connect (OSTI)

    Pashin, J.C.; Raymond, D.E.; Rindsberg, A.K.; Alabi, G.G.; Carroll, R.E.

    1998-09-01

    Gilbertown Field is the oldest oil field in Alabama and has produced oil from fractured chalk of the Cretaceous Selma Group and glauconitic sandstone of the Eutaw Formation. Nearly all of Gilbertown Field is still in primary recovery, although waterflooding has been attempted locally. The objective of this project is to analyze the geologic structure and burial history of Mesozoic and Tertiary strata in Gilbertown Field and adjacent areas in order to suggest ways in which oil recovery can be improved. Indeed, the decline of oil production to marginally economic levels in recent years has made this type of analysis timely and practical. Key technical advancements being sought include understanding the relationship of requisite strain to production in Gilbertown reservoirs, incorporation of synsedimentary growth factors into models of area balance, quantification of the relationship between requisite strain and bed curvature, determination of the timing of hydrocarbon generation, and identification of the avenues and mechanisms of fluid transport.

  16. Factors affecting the recognition of faults exposed in exploratory trenches. Bulletin

    SciTech Connect (OSTI)

    Bonilla, M.G.; Lienkaemper, J.J.

    1991-01-01

    During excavation of the reactor shaft at the proposed Bodega Head nuclear reactor in California, a fault was found in the sediments overlying bedrock. This apparent lack of a complete connection with the bedrock fault led to disagreement as to whether the fault in the sediments was of tectonic or landslide origin. The report provides information on some of the conditions under which fault strands in trench walls are either difficult to see or die out, and the frequency of occurrence of these phenomena. Information is also provided on the widths of fault zones, on the deformation of the hanging wall and footwall of dip-slip faults, and on the frequency of occurrence of pebble rotation, open fissures, gouge, slickensides, mixing, fault breccia, fault rubble, crushing, polishing, water barriers, and liquefaction effects. Short summaries of information relating to fault strands that are poorly expressed or that die out have already been published (Bonilla and Lienkaemper, 1988, 1990).

  17. Photovoltaic System Fault Detection

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Photovoltaic System Fault Detection and Diagnostics using Laterally Primed Adaptive Resonance Theory Neural Network C. Birk Jones, Joshua S. Stein, Sigifredo Gonzalez, and Bruce H. King Sandia National Laboratories, Albuquerque, NM, 87185, U.S.A Abstract-Cost effective integration of solar photovoltaic (PV) systems requires increased reliability. This can be achieved with a robust fault detection and diagnostic (FDD) tool that auto- matically discovers faults. This paper introduces the Laterally

  18. Buried pipelines in large fault movements

    SciTech Connect (OSTI)

    Wang, L.J.; Wang, L.R.L.

    1995-12-31

    Responses of buried pipelines in large fault movements are examined based upon a non-linear cantilever beam analogy. This analogy assumes that the pipeline in a large deflection zone behaves like a cantilever beam under a transverse-concentrated shear at the inflection point with a uniformly distributed soil pressure along the entire span. The tangent modulus approach is adopted to analyze the coupled axial force-bending moment interaction on pipeline deformations in the inelastic range. The buckling load of compressive pipeline is computed by the modified Newmark`s numerical integration scheme. Parametric studies of both tensile and compressive pipeline responses to various fault movements, pipeline/fault crossing angles, soil/pipe friction angles, buried depths, pipe diameters and thickness are investigated. It is shown by the comparisons that previous findings were unconservative.

  19. Fault Detection Tool Project: Automatic Discovery of Faults using...

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Fault Detection Tool Project: Automatic Discovery of Faults using Machine Learning - Sandia Energy Energy Search Icon Sandia Home Locations Contact Us Employee Locator Energy & ...

  20. Solar system fault detection

    DOE Patents [OSTI]

    Farrington, R.B.; Pruett, J.C. Jr.

    1984-05-14

    A fault detecting apparatus and method are provided for use with an active solar system. The apparatus provides an indication as to whether one or more predetermined faults have occurred in the solar system. The apparatus includes a plurality of sensors, each sensor being used in determining whether a predetermined condition is present. The outputs of the sensors are combined in a pre-established manner in accordance with the kind of predetermined faults to be detected. Indicators communicate with the outputs generated by combining the sensor outputs to give the user of the solar system and the apparatus an indication as to whether a predetermined fault has occurred. Upon detection and indication of any predetermined fault, the user can take appropriate corrective action so that the overall reliability and efficiency of the active solar system are increased.

  1. Solar system fault detection

    DOE Patents [OSTI]

    Farrington, Robert B.; Pruett, Jr., James C.

    1986-01-01

    A fault detecting apparatus and method are provided for use with an active solar system. The apparatus provides an indication as to whether one or more predetermined faults have occurred in the solar system. The apparatus includes a plurality of sensors, each sensor being used in determining whether a predetermined condition is present. The outputs of the sensors are combined in a pre-established manner in accordance with the kind of predetermined faults to be detected. Indicators communicate with the outputs generated by combining the sensor outputs to give the user of the solar system and the apparatus an indication as to whether a predetermined fault has occurred. Upon detection and indication of any predetermined fault, the user can take appropriate corrective action so that the overall reliability and efficiency of the active solar system are increased.

  2. Characterization of Quaternary and suspected Quaternary faults, regional studies, Nevada and California

    SciTech Connect (OSTI)

    Anderson, R.E.; Bucknam, R.C.; Crone, A.J.; Haller, K.M.; Machette, M.N.; Personius, S.F.; Barnhard, T.P.; Cecil, M.J.; Dart, R.L.

    1995-12-31

    This report presents the results of geologic studies that help define the Quaternary history of selected faults in the region around Yucca Mountain, Nevada. These results are relevant to the seismic-design basis of a potential nuclear waste repository at Yucca Mountain. The relevancy is based, in part, on a need for additional geologic data that became apparent in ongoing studies that resulted in the identification of 51 relevant and potentially relevant individual and compound faults and fault zones in the 100-km-radius region around the Yucca Mountain site. Geologic data used to characterize the regional faults and fault zones as relevant or potentially relevant seismic sources includes age and displacement information, maximum fault lengths, and minimum distances between the fault and the Yucca Mountain site. For many of the regional faults, no paleoseismic field studies have previously been conducted, and age and displacement data are sparse to nonexistent. In November 1994, the Branch of Earthquake and Landslide Hazards entered into two Memoranda of Agreement with the Yucca Mountain Project Branch to conduct field reconnaissance, analysis, and interpretation of six relevant and six potentially relevant regional faults. This report describes the results of study of those faults exclusive of those in the Pahrump-Stewart Valley-Ash Meadows-Amargosa Valley areas. We also include results of a cursory study of faults on the west flank of the Specter Range and in the northern part of the Last Chance Range. A four-phase strategy was implemented for the field study.

  3. A Thermoelastic Hydraulic Fracture Design Tool for Geothermal Reservoir Development

    SciTech Connect (OSTI)

    Ahmad Ghassemi

    2003-06-30

    Geothermal energy is recovered by circulating water through heat exchange areas within a hot rock mass. Geothermal reservoir rock masses generally consist of igneous and metamorphic rocks that have low matrix permeability. Therefore, cracks and fractures play a significant role in extraction of geothermal energy by providing the major pathways for fluid flow and heat exchange. Thus, knowledge of conditions leading to formation of fractures and fracture networks is of paramount importance. Furthermore, in the absence of natural fractures or adequate connectivity, artificial fracture are created in the reservoir using hydraulic fracturing. At times, the practice aims to create a number of parallel fractures connecting a pair of wells. Multiple fractures are preferred because of the large size necessary when using only a single fracture. Although the basic idea is rather simple, hydraulic fracturing is a complex process involving interactions of high pressure fluid injections with a stressed hot rock mass, mechanical interaction of induced fractures with existing natural fractures, and the spatial and temporal variations of in-situ stress. As a result it is necessary to develop tools that can be used to study these interactions as an integral part of a comprehensive approach to geothermal reservoir development, particularly enhanced geothermal systems. In response to this need we have set out to develop advanced thermo-mechanical models for design of artificial fractures and rock fracture research in geothermal reservoirs. These models consider the significant hydraulic and thermo-mechanical processes and their interaction with the in-situ stress state. Wellbore failure and fracture initiation is studied using a model that fully couples poro-mechanical and thermo-mechanical effects. The fracture propagation model is based on a complex variable and regular displacement discontinuity formulations. In the complex variable approach the displacement discontinuities are defined from the numerical solution of a complex hypersingular integral equation written for a given fracture configuration and loading. The fracture propagation studies include modeling interaction of induced fractures with existing discontinuities such as faults and joints. In addition to the fracture propagation studies, two- and three-dimensional heat extraction solution algorithms have been developed and used to estimate heat extraction and the variations of the reservoir stress with cooling. The numerical models have been developed in a user-friendly environment to create a tool for improving fracture design and investigating single or multiple fracture propagation in rock.

  4. A Comprehensive Study Of Fracture Patterns And Densities In The...

    Open Energy Info (EERE)

    specific knowledge of these in the Geysers area. (2)By locating zones of high fracture density it will be possible to reduce the cost of geothermal power development with the...

  5. Computer hardware fault administration

    DOE Patents [OSTI]

    Archer, Charles J.; Megerian, Mark G.; Ratterman, Joseph D.; Smith, Brian E.

    2010-09-14

    Computer hardware fault administration carried out in a parallel computer, where the parallel computer includes a plurality of compute nodes. The compute nodes are coupled for data communications by at least two independent data communications networks, where each data communications network includes data communications links connected to the compute nodes. Typical embodiments carry out hardware fault administration by identifying a location of a defective link in the first data communications network of the parallel computer and routing communications data around the defective link through the second data communications network of the parallel computer.

  6. Fault tolerant linear actuator

    DOE Patents [OSTI]

    Tesar, Delbert

    2004-09-14

    In varying embodiments, the fault tolerant linear actuator of the present invention is a new and improved linear actuator with fault tolerance and positional control that may incorporate velocity summing, force summing, or a combination of the two. In one embodiment, the invention offers a velocity summing arrangement with a differential gear between two prime movers driving a cage, which then drives a linear spindle screw transmission. Other embodiments feature two prime movers driving separate linear spindle screw transmissions, one internal and one external, in a totally concentric and compact integrated module.

  7. DIFFERENTIAL FAULT SENSING CIRCUIT

    DOE Patents [OSTI]

    Roberts, J.H.

    1961-09-01

    A differential fault sensing circuit is designed for detecting arcing in high-voltage vacuum tubes arranged in parallel. A circuit is provided which senses differences in voltages appearing between corresponding elements likely to fault. Sensitivity of the circuit is adjusted to some level above which arcing will cause detectable differences in voltage. For particular corresponding elements, a group of pulse transformers are connected in parallel with diodes connected across the secondaries thereof so that only voltage excursions are transmitted to a thyratron which is biased to the sensitivity level mentioned.

  8. Self-potential observations during hydraulic fracturing

    SciTech Connect (OSTI)

    Moore, Jeffrey R.; Glaser, Steven D.

    2007-09-13

    The self-potential (SP) response during hydraulic fracturing of intact Sierra granite was investigated in the laboratory. Excellent correlation of pressure drop and SP suggests that the SP response is created primarily by electrokinetic coupling. For low pressures, the variation of SP with pressure drop is linear, indicating a constant coupling coefficient (Cc) of -200 mV/MPa. However for pressure drops >2 MPa, the magnitude of the Cc increases by 80% in an exponential trend. This increasing Cc is related to increasing permeability at high pore pressures caused by dilatancy of micro-cracks, and is explained by a decrease in the hydraulic tortuosity. Resistivity measurements reveal a decrease of 2% prior to hydraulic fracturing and a decrease of {approx}35% after fracturing. An asymmetric spatial SP response created by injectate diffusion into dilatant zones is observed prior to hydraulic fracturing, and in most cases this SP variation revealed the impending crack geometry seconds before failure. At rupture, injectate rushes into the new fracture area where the zeta potential is different than in the rock porosity, and an anomalous SP spike is observed. After fracturing, the spatial SP distribution reveals the direction of fracture propagation. Finally, during tensile cracking in a point load device with no water flow, a SP spike is observed that is caused by contact electrification. However, the time constant of this event is much less than that for transients observed during hydraulic fracturing, suggesting that SP created solely from material fracture does not contribute to the SP response during hydraulic fracturing.

  9. Anastomosing grabens, low-angle faults, and Tertiary thrust( ) faults, western Markagunt Plateau, southwestern Utah

    SciTech Connect (OSTI)

    Maldonado, F.; Sable, E.G. )

    1993-04-01

    A structurally complex terrane composed of grabens and horsts, low-angle faults, Tertiary thrust( ) faults, gravity-slide blocks, and debris deposits has been mapped along the western Markagunt Plateau, east of Parowan and Summit, southwestern Utah. This terrane, structurally situated within the transition between the Basin and Range and Colorado Plateau provinces, contains Tertiary volcanic and sedimentary and Cretaceous sedimentary rocks. The structures are mostly Miocene to Oligocene but some are Pleistocene. The oldest structure is the Red Hills low-angle shear zone, interpreted as a shallow structure that decoupled an upper plate composed of a Miocene-Oligocene volcanic ash-flow tuff and volcaniclastic succession from a lower plate of Tertiary sedimentary rocks. The period of deformation on the shear zone is bracketed from field relationships between 22.5 and 20 Ma. The graben-horst system trends northeast and formed after about 20 Ma (and probably much later) based on displacement of dated dikes and a laccolith. The central part of the system contains many grabens that merge toward its southerly end to become a single graben. Within these grabens, (1) older structures are preserved, (2) debris eroded from horst walls forms lobe-shaped deposits, (3) Pleistocene basaltic cinder cones have localized along graben-bounding faults, and (4) rock units are locally folded suggesting some component of lateral translation along graben-bounding faults. Megabreccia deposits and landslide debris are common. Megabreccia deposits are interpreted as gravity-slide blocks of Miocene-Oligocene( ) age resulting from formation of the Red Hills shear zone, although some may be related to volcanism, and still others to later deformation. The debris deposits are landslides of Pleistocene-Pliocene( ) age possibly caused by continued uplift of the Markagunt Plateau.

  10. Row fault detection system

    DOE Patents [OSTI]

    Archer, Charles Jens; Pinnow, Kurt Walter; Ratterman, Joseph D.; Smith, Brian Edward

    2010-02-23

    An apparatus and program product check for nodal faults in a row of nodes by causing each node in the row to concurrently communicate with its adjacent neighbor nodes in the row. The communications are analyzed to determine a presence of a faulty node or connection.

  11. Row fault detection system

    DOE Patents [OSTI]

    Archer, Charles Jens; Pinnow, Kurt Walter; Ratterman, Joseph D.; Smith, Brian Edward

    2008-10-14

    An apparatus, program product and method checks for nodal faults in a row of nodes by causing each node in the row to concurrently communicate with its adjacent neighbor nodes in the row. The communications are analyzed to determine a presence of a faulty node or connection.

  12. Row fault detection system

    DOE Patents [OSTI]

    Archer, Charles Jens; Pinnow, Kurt Walter; Ratterman, Joseph D.; Smith, Brian Edward

    2012-02-07

    An apparatus, program product and method check for nodal faults in a row of nodes by causing each node in the row to concurrently communicate with its adjacent neighbor nodes in the row. The communications are analyzed to determine a presence of a faulty node or connection.

  13. Final Scientific/Technical Report – DE-EE0002960 Recovery Act. Detachment faulting and Geothermal Resources - An Innovative Integrated Geological and Geophysical Investigation of Pearl Hot Spring, Nevada

    SciTech Connect (OSTI)

    Stockli, Daniel F.

    2015-11-30

    The Pearl Host Spring Geothermal Project funded by the DoE Geothermal Program was a joint academic (KU/UT & OU) and industry collaboration (Sierra and Ram Power) to investigate structural controls and the importance of low-angle normal faults on geothermal fluid flow through a multifaceted geological, geophysical, and geochemical investigation in west-central Nevada. The study clearly showed that the geothermal resources in Clayton Valley are controlled by the interplay between low-angle normal faults and active deformation related to the Walker Lane. The study not only identified potentially feasible blind geothermal resource plays in eastern Clayton Valley, but also provide a transportable template for exploration in the area of west-central Nevada and other regional and actively-deforming releasing fault bends. The study showed that deep-seated low-angle normal faults likely act as crustal scale permeability boundaries and could play an important role in geothermal circulation and funneling geothermal fluid into active fault zones. Not unique to this study, active deformation is viewed as an important gradient to rejuvenated fracture permeability aiding the long-term viability of blind geothermal resources. The technical approach for Phase I included the following components, (1) Structural and geological analysis of Pearl Hot Spring Resource, (2) (U-Th)/He thermochronometry and geothermometry, (3) detailed gravity data and modeling (plus some magnetic and resistivity), (4) Reflection and Refraction Seismic (Active Source), (5) Integration with existing and new geological/geophysical data, and (6) 3-D Earth Model, combining all data in an innovative approach combining classic work with new geochemical and geophysical methodology to detect blind geothermal resources in a cost-effective fashion.

  14. Innovative Methodology for Detection of Fracture-Controlled Sweet Spots in the Northern Appalachian Basin

    SciTech Connect (OSTI)

    Robert Jacobi; John Fountain; Stuart Loewenstein; Edward DeRidder; Bruce Hart

    2007-03-31

    For two consecutive years, 2004 and 2005, the largest natural gas well (in terms of gas flow/day) drilled onshore USA targeted the Ordovician Trenton/Black River (T/BR) play in the Appalachian Basin of New York State (NYS). Yet, little data were available concerning the characteristics of the play, or how to recognize and track T/BR prospects across the region. Traditional exploration techniques for entry into a hot play were of limited use here, since existing deep well logs and public domain seismic were almost non-existent. To help mitigate this problem, this research project was conceived with two objectives: (1) to demonstrate that integrative traditional and innovative techniques could be used as a cost-effective reconnaissance exploration methodology in this, and other, areas where existing data in targeted fracture-play horizons are almost non-existent, and (2) determine critical characteristics of the T/BR fields. The research region between Seneca and Cayuga lakes (in the Finger Lakes of NYS) is on strike and east of the discovery fields, and the southern boundary of the field area is about 8 km north of more recently discovered T/BR fields. Phase I, completed in 2004, consisted of integrating detailed outcrop fracture analyses with detailed soil gas analyses, lineaments, stratigraphy, seismic reflection data, well log data, and aeromagnetics. In the Seneca Lake region, Landsat lineaments (EarthSat, 1997) were coincident with fracture intensification domains (FIDs) and minor faults observed in outcrop and inferred from stratigraphy. Soil gas anomalies corresponded to ENE-trending lineaments and FIDs. N- and ENE-trending lineaments were parallel to aeromagnetic anomalies, whereas E-trending lineaments crossed aeromagnetic trends. 2-D seismic reflection data confirmed that the E-trending lineaments and FIDs occur where shallow level Alleghanian salt-cored thrust-faulted anticlines occur. In contrast, the ENE-trending FIDs and lineaments occur where Iapetan rift faults have been episodically reactivated, and a few of these faults extend through the entire stratigraphic section. The ENE-trending faults and N-striking transfer zones controlled the development of the T/BR grabens. In both the Seneca Lake and Cayuga Lake regions, we found more FIDs than Landsat lineaments, both in terms of individual FIDs and trends of FIDs. Our fused Landsat/ASTER image provided more lineaments, but the structural framework inferred from these lineaments is incomplete even for the fused image. Individual lineaments may not predict surface FIDs (within 500m). However, an individual lineament that has been groundtruthed by outcrop FIDs can be used as a proxy for the trend of intense fracturing. Aeromagnetics and seismic reflection data across the discovery fields west of Keuka Lake demonstrate that the fields terminate on the east against northerly-striking faults that extend from Precambrian basement to, in some cases, the surface; the fields terminate in the west at N- and NW-striking faults. Seismic and well log data show that the fields must be compartmentalized, since different parts of the same field show different histories of development. T/BR fields south of the research area also terminate (on the east) against northerly-trending lineaments which we suggest mark faults. Phase II, completed in 2006, consisted of collection and analysis of an oriented, horizontal core retrieved from one of the T/BR fields in a graben south of the field area. The field is located along ENE-trending EarthSat (1997) lineaments, similar to that hypothesized for the study area. The horizontal core shows much evidence for reactivation along the ENE-trending faults, with multiple events of vein development and both horizontal and vertical stylolite growth. Horizontal veins that post- and pre-date other vein sets indicate that at least two orogenic phases (separated by unloading) affected vein development. Many of the veins and releasing bend features (rhombochasms) are consistent with strike-slip motion (oblique) along ENE-striking faults as a result

  15. Saturated Zone Colloid Transport

    SciTech Connect (OSTI)

    H. S. Viswanathan

    2004-10-07

    This scientific analysis provides retardation factors for colloids transporting in the saturated zone (SZ) and the unsaturated zone (UZ). These retardation factors represent the reversible chemical and physical filtration of colloids in the SZ. The value of the colloid retardation factor, R{sub col} is dependent on several factors, such as colloid size, colloid type, and geochemical conditions (e.g., pH, Eh, and ionic strength). These factors are folded into the distributions of R{sub col} that have been developed from field and experimental data collected under varying geochemical conditions with different colloid types and sizes. Attachment rate constants, k{sub att}, and detachment rate constants, k{sub det}, of colloids to the fracture surface have been measured for the fractured volcanics, and separate R{sub col} uncertainty distributions have been developed for attachment and detachment to clastic material and mineral grains in the alluvium. Radionuclides such as plutonium and americium sorb mostly (90 to 99 percent) irreversibly to colloids (BSC 2004 [DIRS 170025], Section 6.3.3.2). The colloid retardation factors developed in this analysis are needed to simulate the transport of radionuclides that are irreversibly sorbed onto colloids; this transport is discussed in the model report ''Site-Scale Saturated Zone Transport'' (BSC 2004 [DIRS 170036]). Although it is not exclusive to any particular radionuclide release scenario, this scientific analysis especially addresses those scenarios pertaining to evidence from waste-degradation experiments, which indicate that plutonium and americium may be irreversibly attached to colloids for the time scales of interest. A section of this report will also discuss the validity of using microspheres as analogs to colloids in some of the lab and field experiments used to obtain the colloid retardation factors. In addition, a small fraction of colloids travels with the groundwater without any significant retardation. Radionuclides irreversibly sorbed onto this fraction of colloids also transport without retardation. The transport times for these radionuclides will be the same as those for nonsorbing radionuclides. The fraction of nonretarding colloids developed in this analysis report is used in the abstraction of SZ and UZ transport models in support of the total system performance assessment (TSPA) for the license application (LA). This analysis report uses input from two Yucca Mountain Project (YMP) analysis reports. This analysis uses the assumption from ''Waste Form and In-Drift Colloids-Associated Radionuclide Concentrations: Abstraction and Summary'' that plutonium and americium are irreversibly sorbed to colloids generated by the waste degradation processes (BSC 2004 [DIRS 170025]). In addition, interpretations from RELAP analyses from ''Saturated Zone In-Situ Testing'' (BSC 2004 [DIRS 170010]) are used to develop the retardation factor distributions in this analysis.

  16. Seismic signatures of the Lodgepole fractured reservoir in Utah-Wyoming overthrust belt

    SciTech Connect (OSTI)

    Parra, J.; Collier, H.; Angstman, B.

    1997-08-01

    In low porosity, low permeability zones, natural fractures are the primary source of permeability which affect both production and injection of fluids. The open fractures do not contribute much to porosity, but they provide an increased drainage network to any porosity. An important approach to characterizing the fracture orientation and fracture permeability of reservoir formations is one based upon the effects of such conditions on the propagation of acoustic and seismic waves in the rock. We present the feasibility of using seismic measurement techniques to map the fracture zones between wells spaced 2400 ft at depths of about 1000 ft. For this purpose we constructed computer models (which include azimuthal anisotropy) using Lodgepole reservoir parameters to predict seismic signatures recorded at the borehole scale, crosswell scale, and 3 D seismic scale. We have integrated well logs with existing 2D surfaces seismic to produce petrophysical and geological cross sections to determine the reservoir parameters and geometry for the computer models. In particular, the model responses are used to evaluate if surface seismic and crosswell seismic measurements can capture the anisotropy due to vertical fractures. Preliminary results suggested that seismic waves transmitted between two wells will propagate in carbonate fracture reservoirs, and the signal can be received above the noise level at the distance of 2400 ft. In addition, the large velocities contrast between the main fracture zone and the underlying unfractured Boundary Ridge Member, suggested that borehole reflection imaging may be appropriate to map and fracture zone thickness variation and fracture distributions in the reservoir.

  17. The Wallula fault and tectonic framework of south-central Washington, as interpreted from magnetic and gravity anomalies

    SciTech Connect (OSTI)

    Blakely, Richard J.; Sherrod, Brian; Weaver, Craig; Wells, Ray E.; Rohay, Alan C.

    2014-06-11

    Magnetic and gravity data, collected in south-central Washington near the Yakima Fold and Thrust Belt (YFTB) are used to model upper crustal structure, the extent of the late Columbia River Basalt flow named the Ice Harbor member, the vertical conduits (dikes) that the Ice Harbor erupted from, and whether the dikes are offset or affected by faulting on the Wallula Fault zone.

  18. Thermal Waters Along The Konocti Bay Fault Zone, Lake County...

    Open Energy Info (EERE)

    in the diluted spring waters suggest that the diluting water is old. Authors J. M. Thompson, R. H. Mariner, L. D. White, T. S. Presser and W. C. Evans Published Journal Journal...

  19. Fault Mapping | Open Energy Information

    Open Energy Info (EERE)

    to help locate and identify geothermal systems that rely on faults as high permeability pathways for fluid circulation. There are many techniques that can be done to...

  20. Fault current limiter

    DOE Patents [OSTI]

    Darmann, Francis Anthony

    2013-10-08

    A fault current limiter (FCL) includes a series of high permeability posts for collectively define a core for the FCL. A DC coil, for the purposes of saturating a portion of the high permeability posts, surrounds the complete structure outside of an enclosure in the form of a vessel. The vessel contains a dielectric insulation medium. AC coils, for transporting AC current, are wound on insulating formers and electrically interconnected to each other in a manner such that the senses of the magnetic field produced by each AC coil in the corresponding high permeability core are opposing. There are insulation barriers between phases to improve dielectric withstand properties of the dielectric medium.

  1. Characterization of EGS Fracture Network Lifecycles

    SciTech Connect (OSTI)

    Gillian R. Foulger

    2008-03-31

    Geothermal energy is relatively clean, and is an important non-hydrocarbon source of energy. It can potentially reduce our dependence on fossil fuels and contribute to reduction in carbon emissions. High-temperature geothermal areas can be used for electricity generation if they contain permeable reservoirs of hot water or steam that can be extracted. The biggest challenge to achieving the full potential of the nations resources of this kind is maintaining and creating the fracture networks required for the circulation, heating, and extraction of hot fluids. The fundamental objective of the present research was to understand how fracture networks are created in hydraulic borehole injection experiments, and how they subsequently evolve. When high-pressure fluids are injected into boreholes in geothermal areas, they flow into hot rock at depth inducing thermal cracking and activating critically stressed pre-existing faults. This causes earthquake activity which, if monitored, can provide information on the locations of the cracks formed, their time-development and the type of cracking underway, e.g., whether shear movement on faults occurred or whether cracks opened up. Ultimately it may be possible to monitor the critical earthquake parameters in near-real-time so the information can be used to guide the hydraulic injection while it is in progress, e.g., how to adjust factors such as injectate pressure, volume and temperature. In order to achieve this, it is necessary to mature analysis techniques and software that were, at the start of this project, in an embryonic developmental state. Task 1 of the present project was to develop state-of-the-art techniques and software for calculating highly accurate earthquake locations, earthquake source mechanisms (moment tensors) and temporal changes in reservoir structure. Task 2 was to apply the new techniques to hydrofracturing (Enhanced Geothermal Systems, or EGS) experiments performed at the Coso geothermal field, in order to enhance productivity there. Task 3 was to interpret the results jointly with other geological information in order to provide a consistent physical model. All of the original goals of the project have been achieved. An existing program for calculating accurate relative earthquake locations has been enhanced by a technique to improve the accuracy of earthquake arrival-time measurements using waveform cross-correlation. Error analysis has been added to pre-existing moment tensor software. New seismic tomography software has been written to calculate changes in structure that could be due, for example, to reservoir depletion. Data processing procedures have been streamlined and web tools developed for rapid dissemination of the results, e.g., to on-site operations staff. Application of the new analysis tools to the Coso geothermal field has demonstrated the effective use of the techniques and provided important case histories to guide the style of future applications. Changes in reservoir structure with time are imaged throughout the upper 3 km, identifying the areas where large volumes of fluid are being extracted. EGS hydrofracturing experiments in two wells stimulated a nearby fault to the south that ruptured from south to north. The position of this fault could be precisely mapped and its existence was confirmed by surface mapping and data from a borehole televiewer log. No earthquakes occurred far north of the injection wells, suggesting that the wells lie near the northern boundary of the region of critically stressed faults. Minor en-echelon faults were also activated. Significant across-strike fluid flow occurred. The faults activated had significant crack-opening components, indicating that the hydraulic fracturing created open cavities at depth. The fluid injection changed the local stress field orientation and thus the mode of failure was different from the normal background. Initial indications are that the injections modulated stress release, seismicity and natural fracture system evolution for periods of up to months. The research demon

  2. Final Technical Report: PV Fault Detection Tool.

    SciTech Connect (OSTI)

    King, Bruce Hardison; Jones, Christian Birk

    2015-12-01

    The PV Fault Detection Tool project plans to demonstrate that the FDT can (a) detect catastrophic and degradation faults and (b) identify the type of fault. This will be accomplished by collecting fault signatures using different instruments and integrating this information to establish a logical controller for detecting, diagnosing and classifying each fault.

  3. Geothermal Ultrasonic Fracture Imager

    Broader source: Energy.gov [DOE]

    Development of a downhole wireline tool to characterize fractures in EGS wells in temperatures up to 300°C and depths up to 10; 000 m.

  4. Fracture detection logging tool

    DOE Patents [OSTI]

    Benzing, William M.

    1992-06-09

    A method and apparatus by which fractured rock formations are identified and their orientation may be determined includes two orthogonal motion sensors which are used in conjunction with a downhole orbital vibrator. The downhole vibrator includes a device for orienting the sensors. The output of the sensors is displayed as a lissajou figure. The shape of the figure changes when a subsurface fracture is encountered in the borehole. The apparatus and method identifies fractures rock formations and enables the azimuthal orientation of the fractures to be determined.

  5. Arc fault detection system

    DOE Patents [OSTI]

    Jha, K.N.

    1999-05-18

    An arc fault detection system for use on ungrounded or high-resistance-grounded power distribution systems is provided which can be retrofitted outside electrical switchboard circuits having limited space constraints. The system includes a differential current relay that senses a current differential between current flowing from secondary windings located in a current transformer coupled to a power supply side of a switchboard, and a total current induced in secondary windings coupled to a load side of the switchboard. When such a current differential is experienced, a current travels through a operating coil of the differential current relay, which in turn opens an upstream circuit breaker located between the switchboard and a power supply to remove the supply of power to the switchboard. 1 fig.

  6. Arc fault detection system

    DOE Patents [OSTI]

    Jha, Kamal N.

    1999-01-01

    An arc fault detection system for use on ungrounded or high-resistance-grounded power distribution systems is provided which can be retrofitted outside electrical switchboard circuits having limited space constraints. The system includes a differential current relay that senses a current differential between current flowing from secondary windings located in a current transformer coupled to a power supply side of a switchboard, and a total current induced in secondary windings coupled to a load side of the switchboard. When such a current differential is experienced, a current travels through a operating coil of the differential current relay, which in turn opens an upstream circuit breaker located between the switchboard and a power supply to remove the supply of power to the switchboard.

  7. Imaging Faults with Reverse-Time Migration for Geothermal Exploration at Jemez Pueblo in New Mexico

    SciTech Connect (OSTI)

    Huang, Lianjie; Albrecht, Michael; Kaufman, Greg; Kelley, Shari; Rehfeldt, Kenneth; Zhang, Zhifu

    2011-01-01

    The fault zones at Jemez Pueblo may dominate the flow paths of hot water, or confine the boundaries of the geothermal reservoir. Therefore, it is crucial to image the geometry of these fault zones for geothermal exploration in the area. We use reverse-time migration with a separation imaging condition to image the faults at Jemez Pueblo. A finite-difference full-wave equation method with a perfectly-matching-layer absorbing boundary condition is used for backward propagation of seismic reflection data from receivers and forward propagation of wavefields from sources. In the imaging region, the wavefields are separated into the upgoing and downgoing waves, and leftgoing and rightgoing waves. The upgoing and downgoing waves are used to obtain the downward-looking image, and the leftgoing and rightgoing waves are used to form the left-looking image and right-looking image from sources. The left-looking and right-looking images are normally weaker than the downward-looking image because the reflections from the fault zones are much weaker than those from sedimentary layers, but these migration results contain the images of the faults. We apply our reverse-time migration with a wavefield separation imaging condition to seismic data acquired at Jemez Pueblo, and our preliminary results reveal many faults in the area.

  8. Induced fractures: well stimulation through fracturing

    SciTech Connect (OSTI)

    Hanold, R.J.

    1982-01-01

    Seven fracture stimulation treatments were planned and executed under the Department of Energy-funded Geothermal Well Stimulation Program. The objective of this program is to demonstrate that geothermal well stimulation offers a technical alternative to additional well drilling and redrilling for productivity enhancement which can substantially reduce development costs. Well stimulation treatments have been performed at Raft River, Idaho; East Mesa, California; The Geysers, California; and the Baca Project Area in New Mexico. Six of the seven stimulation experiments were technically successful in stimulating the wells. The two fracture treatments in East Mesa more than doubled the production rate of the previously marginal producer. The two fracture treatments at Raft River and the two at Baca were all successful in obtaining significant production from previously nonproductive intervals. The acid etching treatment in the well at the Geysers did not have any material effect on production rate.

  9. Design and Implementation of Energized Fracture Treatment in Tight Gas Sands

    SciTech Connect (OSTI)

    Mukul Sharma; Kyle Friehauf

    2009-12-31

    Hydraulic fracturing is essential for producing gas and oil at an economic rate from low permeability sands. Most fracturing treatments use water and polymers with a gelling agent as a fracturing fluid. The water is held in the small pore spaces by capillary pressure and is not recovered when drawdown pressures are low. The un-recovered water leaves a water saturated zone around the fracture face that stops the flow of gas into the fracture. This is a particularly acute problem in low permeability formations where capillary pressures are high. Depletion (lower reservoir pressures) causes a limitation on the drawdown pressure that can be applied. A hydraulic fracturing process can be energized by the addition of a compressible, sometimes soluble, gas phase into the treatment fluid. When the well is produced, the energized fluid expands and gas comes out of solution. Energizing the fluid creates high gas saturation in the invaded zone, thereby facilitating gas flowback. A new compositional hydraulic fracturing model has been created (EFRAC). This is the first model to include changes in composition, temperature, and phase behavior of the fluid inside the fracture. An equation of state is used to evaluate the phase behavior of the fluid. These compositional effects are coupled with the fluid rheology, proppant transport, and mechanics of fracture growth to create a general model for fracture creation when energized fluids are used. In addition to the fracture propagation model, we have also introduced another new model for hydraulically fractured well productivity. This is the first and only model that takes into account both finite fracture conductivity and damage in the invaded zone in a simple analytical way. EFRAC was successfully used to simulate several fracture treatments in a gas field in South Texas. Based on production estimates, energized fluids may be required when drawdown pressures are smaller than the capillary forces in the formation. For this field, the minimum CO{sub 2} gas quality (volume % of gas) recommended is 30% for moderate differences between fracture and reservoir pressures (2900 psi reservoir, 5300 psi fracture). The minimum quality is reduced to 20% when the difference between pressures is larger, resulting in additional gas expansion in the invaded zone. Inlet fluid temperature, flow rate, and base viscosity did not have a large impact on fracture production. Finally, every stage of the fracturing treatment should be energized with a gas component to ensure high gas saturation in the invaded zone. A second, more general, sensitivity study was conducted. Simulations show that CO{sub 2} outperforms N{sub 2} as a fluid component because it has higher solubility in water at fracturing temperatures and pressures. In fact, all gas components with higher solubility in water will increase the fluid's ability to reduce damage in the invaded zone. Adding methanol to the fracturing solution can increase the solubility of CO{sub 2}. N{sub 2} should only be used if the gas leaks-off either during the creation of the fracture or during closure, resulting in gas going into the invaded zone. Experimental data is needed to determine if the gas phase leaks-off during the creation of the fracture. Simulations show that the bubbles in a fluid traveling across the face of a porous medium are not likely to attach to the surface of the rock, the filter cake, or penetrate far into the porous medium. In summary, this research has created the first compositional fracturing simulator, a useful tool to aid in energized fracture design. We have made several important and original conclusions about the best practices when using energized fluids in tight gas sands. The models and tools presented here may be used in the future to predict behavior of any multi-phase or multi-component fracturing fluid system.

  10. Fault Detection Tool Project: Automatic Discovery of Faults using Machine

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Learning Fault Detection Tool Project: Automatic Discovery of Faults using Machine Learning - Sandia Energy Energy Search Icon Sandia Home Locations Contact Us Employee Locator Energy & Climate Secure & Sustainable Energy Future Stationary Power Energy Conversion Efficiency Solar Energy Wind Energy Water Power Supercritical CO2 Geothermal Natural Gas Safety, Security & Resilience of the Energy Infrastructure Energy Storage Nuclear Power & Engineering Grid Modernization

  11. EVALUATION OF ENHANCED VOC REMOVAL WITH SOIL FRACTURING IN THE SRS UPLAND UNIT

    SciTech Connect (OSTI)

    Riha, B

    2005-10-31

    The Environmental Restoration Technology Section (ERTS) of the Savannah River National Laboratory (SRNL) conducted pilot scale testing to evaluate the effectiveness of using hydraulic fracturing as a means to improve soil vapor extraction (SVE) system performance. Laboratory and field research has shown that significant amounts of solvents can be entrapped in low permeability zones by capillary forces and removal by SVE can be severely limited due to low flow rates, mass transfer resistance of the hydrophobic compounds by trapped interparticle water, and diffusion resistance. Introducing sand-filled fractures into these tight zones improves the performance of SVE by (1) increasing the overall permeability of the formation and thereby increasing SVE flow rates, (2) shortening diffusion pathways, and (3) increasing air permeability by improving pore water removal. The synergistic effect of the fracture well completion methods, fracture and flow geometry, and pore water removal appears to increase the rate of solvent mass removal over that of increasing flow rate alone. A field test was conducted where a conventional well in the SRS Upland Unit was tested before and after hydraulic fracturing. ERTS teamed with Clemson University through the South Carolina University and Education Foundation (SCUREF) program utilizing their expertise in fracturing and fracture modeling. The goals of the fracturing pilot testing were to evaluate the following: (1) The effect of hydraulic fractures on the performance of a conventional well. This was the most reliable way to remove the effects of spatial variations in permeability and contaminant distribution on relative well performance. It also provided data on the option of improving the performance of existing wells using hydraulic fractures. (2) The relative performance of a conventional SVE well and isolated hydraulic fractures. This was the most reliable indicator of the performance of hydraulic fractures that could be created in a full-scale implementation. The SVE well, monitoring point arrays and four fracturing wells were installed and the well testing has been completed. Four fractures were successfully created the week of July 25, 2005. The fractures were created in an open area at the bottom of steel well casing by using a water jet to create a notch in the soil and then injecting a guar-sand slurry into the formation. The sand-filled fractures increase the effective air permeability of the subsurface formation diffusion path lengths for contaminant removal. The primary metrics for evaluation were an increase in SVE flow rates in the zone of contamination and an increase in the zone of influence. Sufficient testing has been performed to show that fracturing in the Upland Unit accelerates SVE solvent remediation and fracturing can increase flow rates in the Upland Unit by at least one order of magnitude.

  12. Influence of Transcontinental arch on Cretaceous listric-normal faulting, west flank, Denver basin

    SciTech Connect (OSTI)

    Davis, T.L.

    1983-08-01

    Seismic studies along the west flank of the Denver basin near Boulder and Greeley, Colorado illustrate the interrelationship between shallow listric-normal faulting in the Cretaceous and deeper basement-controlled faulting. Deeper fault systems, primarily associated with the Transcontinental arch, control the styles and causative mechanisms of listric-normal faulting that developed in the Cretaceous. Three major stratigraphic levels of listric-normal faulting occur in the Boulder-Greeley area. These tectonic sensitive intervals are present in the following Cretaceous formations: Laramie-Fox Hills-upper Pierre, middle Pierre Hygiene zone, and the Niobrara-Carlile-Greenhorn. Documentation of the listric-normal fault style reveals a Wattenberg high, a horst block or positive feature of the greater Transcontinental arch, was active in the east Boulder-Greeley area during Cretaceous time. Paleotectonic events associated with the Wattenberg high are traced through analysis of the listric-normal fault systems that occur in the area. These styles are important to recognize because of their stratigraphic and structural influence on Cretaceous petroleum reservoir systems in the Denver basin. Similar styles of listric-normal faulting occur in the Cretaceous in many Rocky Mountain foreland basins.

  13. Hot Pot Detail - Evidence of Quaternary Faulting

    SciTech Connect (OSTI)

    Lane, Michael

    2013-06-27

    Compilation of published data, field observations and photo interpretation relevant to Quaternary faulting at Hot Pot.

  14. Hot Pot Detail - Evidence of Quaternary Faulting

    DOE Data Explorer [Office of Scientific and Technical Information (OSTI)]

    Lane, Michael

    Compilation of published data, field observations and photo interpretation relevant to Quaternary faulting at Hot Pot.

  15. Multi-zone methods to predict gas well performance

    SciTech Connect (OSTI)

    Blanchard, L.A.; Newhouse, J.R.

    1982-01-01

    The contributing elements of a formula developed for accurately predicting the performance of gas wells which include a high permeability zone interbedded with one or more low permeability zones are discussed. The theory assumes the existence of 3 conditions: (1) the well depletes without water encroachment; (2) each zone remains discreet from every other - that is, without cross flow among zones when the well is producing; and (3) each zone has either a hydraulic fracture or some skin effect. As a practical matter in using the model, only one of these reservoir conditions need to be met - freedom from water encroachment. The model developed does not adapt to reservoirs that have limited cross flow between zones. It also adapts to those with a hydraulic fracture in only some of the zones and includes equations which help to calculate matrix permeability whenever a known hydraulic fracture does exist. The functions of the model are illustrated by assuming the existence of a shaley-sand, 6-zone reservoir and by ascribing to it certain characteristics. The use of the model is examined and its results are discussed.

  16. Fault Controlled | Open Energy Information

    Open Energy Info (EERE)

    has been provided for this term. Add a Definition This classification is used if the literature describes the geothermal fluids as being controlled by faults, but not in detail....

  17. Cell boundary fault detection system

    DOE Patents [OSTI]

    Archer, Charles Jens; Pinnow, Kurt Walter; Ratterman, Joseph D.; Smith, Brian Edward

    2009-05-05

    A method determines a nodal fault along the boundary, or face, of a computing cell. Nodes on adjacent cell boundaries communicate with each other, and the communications are analyzed to determine if a node or connection is faulty.

  18. Modifications of Carbonate Fracture Hydrodynamic Properties by CO{sub 2}-Acidified Brine Flow

    SciTech Connect (OSTI)

    Deng, Hang; Ellis, Brian R.; Peters, Catherine A.; Fitts, Jeffrey P.; Crandall, Dustin; Bromhal, Grant S.

    2013-08-01

    Acidic reactive flow in fractures is relevant in subsurface activities such as CO{sub 2} geological storage and hydraulic fracturing. Understanding reaction-induced changes in fracture hydrodynamic properties is essential for predicting subsurface flows such as leakage, injectability, and fluid production. In this study, x-ray computed tomography scans of a fractured carbonate caprock were used to create three dimensional reconstructions of the fracture before and after reaction with CO{sub 2}-acidified brine (Ellis et al., 2011, Greenhouse Gases: Sci. Technol., 1:248-260). As expected, mechanical apertures were found to increase substantially, doubling and even tripling in some places. However, the surface geometry evolved in complex ways including comb-tooth structures created from preferential dissolution of calcite in transverse sedimentary bands, and the creation of degraded zones, i.e. porous calcite-depleted areas on reacted fracture surfaces. These geometric alterations resulted in increased fracture roughness, as measured by surface Z{sub 2} parameters and fractal dimensions D{sub f}. Computational fluid dynamics (CFD) simulations were conducted to quantify the changes in hydraulic aperture, fracture transmissivity and permeability. The results show that the effective hydraulic apertures are smaller than the mechanical apertures, and the changes in hydraulic apertures are nonlinear. Overestimation of flow rate by a factor of two or more would be introduced if fracture hydrodynamic properties were based on mechanical apertures, or if hydraulic aperture is assumed to change proportionally with mechanical aperture. The differences can be attributed, in part, to the increase in roughness after reaction, and is likely affected by contiguous transverse sedimentary features. Hydraulic apertures estimated by the 1D statistical model and 2D local cubic law (LCL) model are consistently larger than those calculated from the CFD simulations. In addition, a novel ternary segmentation method was devised to handle the degraded zones, allowing for a bounding analysis of the effects on hydraulic properties. We found that the degraded zones account for less than 15% of the fracture volume, but cover 70% to 80% of the fracture surface. When the degraded zones are treated as part of the fracture, the fracture transmissivities are two to four times larger because the fracture surfaces after reaction are not as rough as they would be if one considers the degraded zone as part of the rock. Therefore, while degraded zones created during geochemical reactions may not significantly increase mechanical aperture, this type of feature cannot be ignored and should be treated with prudence when predicting fracture hydrodynamic properties.

  19. Passive fault current limiting device

    DOE Patents [OSTI]

    Evans, D.J.; Cha, Y.S.

    1999-04-06

    A passive current limiting device and isolator is particularly adapted for use at high power levels for limiting excessive currents in a circuit in a fault condition such as an electrical short. The current limiting device comprises a magnetic core wound with two magnetically opposed, parallel connected coils of copper, a high temperature superconductor or other electrically conducting material, and a fault element connected in series with one of the coils. Under normal operating conditions, the magnetic flux density produced by the two coils cancel each other. Under a fault condition, the fault element is triggered to cause an imbalance in the magnetic flux density between the two coils which results in an increase in the impedance in the coils. While the fault element may be a separate current limiter, switch, fuse, bimetal strip or the like, it preferably is a superconductor current limiter conducting one-half of the current load compared to the same limiter wired to carry the total current of the circuit. The major voltage during a fault condition is in the coils wound on the common core in a preferred embodiment. 6 figs.

  20. Passive fault current limiting device

    DOE Patents [OSTI]

    Evans, Daniel J.; Cha, Yung S.

    1999-01-01

    A passive current limiting device and isolator is particularly adapted for use at high power levels for limiting excessive currents in a circuit in a fault condition such as an electrical short. The current limiting device comprises a magnetic core wound with two magnetically opposed, parallel connected coils of copper, a high temperature superconductor or other electrically conducting material, and a fault element connected in series with one of the coils. Under normal operating conditions, the magnetic flux density produced by the two coils cancel each other. Under a fault condition, the fault element is triggered to cause an imbalance in the magnetic flux density between the two coils which results in an increase in the impedance in the coils. While the fault element may be a separate current limiter, switch, fuse, bimetal strip or the like, it preferably is a superconductor current limiter conducting one-half of the current load compared to the same limiter wired to carry the total current of the circuit. The major voltage during a fault condition is in the coils wound on the common core in a preferred embodiment.

  1. Fracture mechanics: 26. volume

    SciTech Connect (OSTI)

    Reuter, W.G.; Underwood, J.H.; Newman, J.C. Jr.

    1995-12-31

    The original objective of these symposia was to promote technical interchange between researchers from the US and worldwide in the field of fracture. This objective was recently expanded to promote technical interchange between researchers in the field of fatigue and fracture. The symposium began with the Swedlow Memorial Lecture entitled ``Patterns and Perspectives in Applied Fracture Mechanics.`` The remaining 42 papers are divided into the following topical sections: Constraint crack initiation; Constraint crack growth; Weldments; Engineered materials; Subcritical crack growth; Dynamic loading; and Applications. Papers within the scope of the Energy Data Base have been processed separately.

  2. Seismicity and Reservoir Fracture Characterization

    Broader source: Energy.gov [DOE]

    Below are the project presentations and respective peer review results for Seismicity and Reservoir Fracture Characterization.

  3. INNOVATIVE METHODOLOGY FOR DETECTION OF FRACTURE-CONTROLLED SWEET SPOTS IN THE NORTHERN APPALACHIAN BASIN

    SciTech Connect (OSTI)

    Robert Jacobi; John Fountain

    2001-06-30

    In the structure task, the authors completed reducing the data they had collected from a N-S transect on the east side of Seneca Lake. They have calculated the fracture frequency for all the fracture sets at each site, and constructed modified rose diagrams that summarize the fracture attributes at each site. These data indicate a N-striking fault near the southeastern shore of Seneca Lake, and also indicate NE and ENE-trending FIDs and faults north of Valois. The orientation and existence of the ENE-striking FIDs and faults are thought to be guided by faults in the Precambrian basement. These basement faults apparently were sufficiently reactivated to cause faulting in the Paleozoic section. Other faults are thrust ramps above the Silurian salt section that were controlled by a far-field Alleghanian stress field. Structure contour maps and isopach maps have been revised based on additional well log analyses. Except for the Glodes Corners Field, the well spacing generally is insufficient to definitely identify faults. However, relatively sharp elevational changes east of Keuka Lake support the contention that faults occur along the east side of Keuka Lake. Outcrop stratigraphy along the east side of Seneca Lake indicates that faults and gentle folds can be inferred from some exposures along Seneca Lake, but the lensing nature of the individual sandstones can preclude long-distance definite correlations and structure identification. Soil gas data collected during the 2000 field season was reduced and displayed in the previous semiannual report. The seismic data that Quest licensed has been reprocessed. Several grabens observed in the Trenton reflector are consistent with surface structure, soil gas, and aeromagnetic anomalies. In this report they display an interpreted seismic line that crosses the Glodes Corners and Muck Farms fields. The final report from the subcontractor concerning the completed aeromagnetic survey is included. Prominent magnetic anomalies suggest that faults in the Precambrian basement are located beneath regions where grabens in the Trenton are located. The trend and location of these faults based on aeromagnetics agrees with the location based on FIDs. These data indicate that integration of aeromagnetic and topographic lineaments, surface structure, soil gas with seismic and well logs allows them to extrapolate Trenton-Black River trends away from confirmatory seismic lines.

  4. INNOVATIVE METHODOLOGY FOR DETECTION OF FRACTURE-CONTROLLED SWEET SPOTS IN THE NORTHERN APPALACHIAN BASIN

    SciTech Connect (OSTI)

    Robert Jacobi; John Fountain

    2002-01-30

    In the structure task, we completed reducing the data we had collected from a N-S transect on the east of Seneca Lake. We have calculated the fracture frequency for all the fracture sets at each site, and constructed modified rose diagrams that summarize the fracture attributes at each site. These data indicate a N-striking fault near the southeastern shore of Seneca Lake, and also indicate NE and ENE-trending FIDs and faults north of Valois. The orientation and existence of the ENE-striking FIDs and faults are thought to be guided by faults in the Precambrian basement; these basement faults apparently were sufficiently reactivated to cause faulting in the Paleozoic section. Other faults are thrust ramps above the Silurian salt section that were controlled by a far-field Alleghanian stress field. Structure contour maps and isopach maps have been revised based on additional well log analyses. Except for the Glodes Corners Field, the well spacing generally is insufficient to definitively identify faults. However, relatively sharp elevational changes east of Keuka Lake support the contention that faults occur along the east side of Keuka Lake. Outcrop stratigraphy along the east side of Seneca Lake indicates that faults and gentle folds can be inferred from the some exposures along Seneca Lake, but the lensing nature of the individual sandstones can preclude long-distance definitive correlations and structure identification. Soil gas data collected during the 2000 field season was reduced and displayed in the previous semiannual report. The seismic data that Quest licensed has been reprocessed. Several grabens observed in the Trenton reflector are consistent with surface structure, soil gas, and aeromagnetic anomalies. In this report we display an interpreted seismic line that crosses the Glodes Corners and Muck Farm fields. The final report from the subcontractor concerning the completed aeromagnetic survey is included. Prominent magnetic anomalies suggest that faults in the Precambrian basement are located beneath regions where grabens in the Trenton are located. The trend and location of these faults based on aeromagnetics agrees with the location based on FIDs. These data indicate that integration of aeromagnetic and topographic lineaments, surface structure, soil gas with seismic and well logs allows us to extrapolate Trenton-Black River trends away from confirmatory seismic lines.

  5. Preliminary 3-D site-scale studies of radioactive colloid transortin the unsaturated zone at Yucca Mountain, Nevada

    SciTech Connect (OSTI)

    Moridis, G.J.; Hu, Q.; Wu, Y.-S.; Bodvarsson, G.S.

    2001-09-01

    The U.S: Department of Energy is actively investigating the technical feasibility of permanent disposal of high-level nuclear waste in a repository to be situated in the unsaturated zone at Yucca Mountain, Nevada. In this study we investigate, by means of numerical simulation, the transport of radioactive colloids under ambient conditions from the potential repository horizon to the water table. The site hydrology and the effects of the spatial distribution of hydraulic and transport properties in the Yucca Mountain subsurface are considered. The study of migration and retardation of colloids accounts for the complex processes in the unsaturated zone of Yucca Mountain, and includes advection, diffusion, hydrodynamic dispersion, kinetic colloid filtration, colloid straining, and radioactive decay. The results of the study indicate that the most important factors affecting colloid transport are the subsurface geology and site hydrology, i.e., the presence of faults (they dominate and control transport), fractures (the main migration pathways), and the relative distribution of zeolitic and vitric tuffs. The transport of colloids is strongly influenced by their size (as it affects diffusion into the matrix, straining at hydrogeologic unit interfaces, and transport velocity) and by the parameters of the kinetic-filtration model used for the simulations. Arrival times at the water table decrease with an increasing colloid size because of smaller diffusion, increased straining, and higher transport velocities. The importance of diffusion as a retardation mechanism increases with a decreasing colloid size, but appears to be minimal in large colloids.

  6. Subsurface fracture mapping from geothermal wellbores. Final report

    SciTech Connect (OSTI)

    Hartenbaum, B.A.; Rawson, G.

    1983-08-01

    To advance the state-of-the-art in Hot Dry Rock technology, and evaluation is made of (1) the use of both electromagnetic and acoustic radar to map far-field fractures, (2) the use of more than twenty different conventional well logging tools to map borehole-fracture intercepts, (3) the use of magnetic dipole ranging to determine the relative positions of the injection well and the production well within the fractured zone, (4) the use of passive microseismic methods to determine the orientation and extent of hydraulic fractures, and (5) the application of signal processing techniques to fracture mapping including tomography, holography, synthetic aperture, image reconstruction, and the relative importance of phase and amplitude information. It is found that according to calculations, VHF backscatter radar has the potential for mapping fractures within a distance of 50 +- 20 meters from the wellbore. A new technique for improving fracture identification is presented. The range of acoustic radar is five to seven times greater than that of VHF radar when compared on the basis of equal resolution, i.e., equal wavelengths. Analyses of extant data indicate that when used synergistically the (1) caliper, (2) resistivity dipmeter, (3) televiewer, (4) television, (5) impression packer, and (6) acoustic transmission are useful for mapping borehole-fracture intercepts. A new model of hydraulic fracturing is presented which indicates that a hydraulic fracture is dynamically unstable; consequently, improvements in locating the crack tip may be possible. The importance of phase in signal processing is stressed and those techniques which employ phase data are emphasized for field use.

  7. Zone separator for multiple zone vessels

    DOE Patents [OSTI]

    Jones, John B.

    1983-02-01

    A solids-gas contact vessel, having two vertically disposed distinct reaction zones, includes a dynamic seal passing solids from an upper to a lower zone and maintaining a gas seal against the transfer of the separate treating gases from one zone to the other, and including a stream of sealing fluid at the seal.

  8. Shale Gas Development Challenges: Fracture Fluids | Department...

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    Fracture Fluids Shale Gas Development Challenges: Fracture Fluids PDF icon Shale Gas Development Challenges: Fracture Fluids More Documents & Publications Natural Gas from Shale: ...

  9. Embedded atom calculations of unstable stacking fault energies and surface energies in intermetallics

    SciTech Connect (OSTI)

    Farkas, D.; Zhou, S.J.; Vailhe, C.; Mutasa, B.; Panova, J.

    1997-01-01

    We performed embedded atom method calculations on surface energies and unstable stacking fault energies for a series of intermetallics for which interatomic potentials of the embedded atom type have recently been developed. These results were analyzed and applied to the prediction of relative ductility of these materials using the various current theories. Series of alloys with the B2 ordered structure were studied, and the results were compared to those in pure body-centered cubic (bcc) Fe. Ordered compounds with L1{sub 2} and L1{sub 0} structures based on the face-centered cubic (fcc) lattice were also studied. It was found that there is a correlation between the values of the antiphase boundary (APB) energies in B2 alloys and their unstackable stacking fault energies. Materials with higher APB energies tend to have higher unstable stacking fault energies, leading to an increased tendency to brittle fracture. {copyright} {ital 1997 Materials Research Society.}

  10. Unsaturated Zone and Saturated Zone Transport Properties (U0100)

    SciTech Connect (OSTI)

    J. Conca

    2000-12-20

    This Analysis/Model Report (AMR) summarizes transport properties for the lower unsaturated zone hydrogeologic units and the saturated zone at Yucca Mountain and provides a summary of data from the Busted Butte Unsaturated Zone Transport Test (UZTT). The purpose of this report is to summarize the sorption and transport knowledge relevant to flow and transport in the units below Yucca Mountain and to provide backup documentation for the sorption parameters decided upon for each rock type. Because of the complexity of processes such as sorption, and because of the lack of direct data for many conditions that may be relevant for Yucca Mountain, data from systems outside of Yucca Mountain are also included. The data reported in this AMR will be used in Total System Performance Assessment (TSPA) calculations and as general scientific support for various Process Model Reports (PMRs) requiring knowledge of the transport properties of different materials. This report provides, but is not limited to, sorption coefficients and other relevant thermodynamic and transport properties for the radioisotopes of concern, especially neptunium (Np), plutonium (Pu), Uranium (U), technetium (Tc), iodine (I), and selenium (Se). The unsaturated-zone (UZ) transport properties in the vitric Calico Hills (CHv) are discussed, as are colloidal transport data based on the Busted Butte UZTT, the saturated tuff, and alluvium. These values were determined through expert elicitation, direct measurements, and data analysis. The transport parameters include information on interactions of the fractures and matrix. In addition, core matrix permeability data from the Busted Butte UZTT are summarized by both percent alteration and dispersion.

  11. Thoughts Regarding the Dimensions of Faults at Rainier and Aqueduct Mesas, Nye County, Nevada, Based on Surface and Underground Mapping

    SciTech Connect (OSTI)

    Drellack, S.L.; Prothro, L.B.; Townsend, M.J.; Townsend, D.R.

    2011-02-01

    The geologic setting and history, along with observations through 50 years of detailed geologic field work, show that large-displacement (i.e., greater than 30 meters of displacement) syn- to post-volcanic faults are rare in the Rainier Mesa area. Faults observed in tunnels and drill holes are mostly tight, with small displacements (most less than 1.5 meters) and small associated damage zones. Faults are much more abundant in the zeolitized tuffs than in the overlying vitric tuffs, and there is little evidence that faults extend downward from the tuff section through the argillic paleocolluvium into pre-Tertiary rocks. The differences in geomechanical characteristics of the various tuff lithologies at Rainier Mesa suggest that most faults on Rainer Mesa are limited to the zeolitic units sandwiched between the overlying vitric bedded tuffs and the underlying pre-Tertiary units (lower carbonate aquifer3, lower clastic confining unit1, and Mesozoic granite confining unit).

  12. Fracture-Flow-Enhanced Solute Diffusion into Fractured Rock

    SciTech Connect (OSTI)

    Wu, Yu-Shu; Ye, Ming; Sudicky, E.A.

    2007-12-15

    We propose a new conceptual model of fracture-flow-enhanced matrix diffusion, which correlates with fracture-flow velocity, i.e., matrix diffusion enhancement induced by rapid fluid flow within fractures. According to the boundary-layer or film theory, fracture flow enhanced matrix diffusion may dominate mass-transfer processes at fracture-matrix interfaces, because rapid flow along fractures results in large velocity and concentration gradients at and near fracture-matrix interfaces, enhancing matrix diffusion at matrix surfaces. In this paper, we present a new formulation of the conceptual model for enhanced fracture-matrix diffusion, and its implementation is discussed using existing analytical solutions and numerical models. In addition, we use the enhanced matrix diffusion concept to analyze laboratory experimental results from nonreactive and reactive tracer breakthrough tests, in an effort to validate the new conceptual model.

  13. DEM Particle Fracture Model

    SciTech Connect (OSTI)

    Zhang, Boning; Herbold, Eric B.; Homel, Michael A.; Regueiro, Richard A.

    2015-12-01

    An adaptive particle fracture model in poly-ellipsoidal Discrete Element Method is developed. The poly-ellipsoidal particle will break into several sub-poly-ellipsoids by Hoek-Brown fracture criterion based on continuum stress and the maximum tensile stress in contacts. Also Weibull theory is introduced to consider the statistics and size effects on particle strength. Finally, high strain-rate split Hopkinson pressure bar experiment of silica sand is simulated using this newly developed model. Comparisons with experiments show that our particle fracture model can capture the mechanical behavior of this experiment very well, both in stress-strain response and particle size redistribution. The effects of density and packings o the samples are also studied in numerical examples.

  14. Cell boundary fault detection system

    DOE Patents [OSTI]

    Archer, Charles Jens; Pinnow, Kurt Walter; Ratterman, Joseph D.; Smith, Brian Edward

    2011-04-19

    An apparatus and program product determine a nodal fault along the boundary, or face, of a computing cell. Nodes on adjacent cell boundaries communicate with each other, and the communications are analyzed to determine if a node or connection is faulty.

  15. High temperature superconducting fault current limiter

    DOE Patents [OSTI]

    Hull, J.R.

    1997-02-04

    A fault current limiter for an electrical circuit is disclosed. The fault current limiter includes a high temperature superconductor in the electrical circuit. The high temperature superconductor is cooled below its critical temperature to maintain the superconducting electrical properties during operation as the fault current limiter. 15 figs.

  16. High temperature superconducting fault current limiter

    DOE Patents [OSTI]

    Hull, John R.

    1997-01-01

    A fault current limiter (10) for an electrical circuit (14). The fault current limiter (10) includes a high temperature superconductor (12) in the electrical circuit (14). The high temperature superconductor (12) is cooled below its critical temperature to maintain the superconducting electrical properties during operation as the fault current limiter (10).

  17. CHARACTERIZATION OF IN-SITU STRESS AND PERMEABILITY IN FRACTURED RESERVOIRS

    SciTech Connect (OSTI)

    Daniel R. Burns; M. Nafi Toksoz

    2003-07-10

    A 3-D elastic wave propagation finite difference model, including effects of attenuation, has been implemented and compared with other existing modeling codes for validation. Models of seismic scattering from discrete large-scale fractures as well as equivalent anisotropic medium representations of small-scale fractures have been generated and used to develop data analysis methods for applications to seismic field data. An inversion scheme has been developed to estimate fracture orientation and fracture density from amplitude variations with offset and azimuth (AVOA). The method has been tested on synthetic data and field data from an offshore fractured carbonate reservoir with promising results. Spectral characteristics of the numerical model data of the seismic wavefield scattered from aligned fractures with different spacing between fracture zones have been analyzed. Results indicate that the spacing of these large, open fracture zones can be estimated from the wavenumber spectra of the scattered wave amplitude as a function of offset in pre-stack data. Two approaches for converting seismically derived fracture parameters into fluid-flow parameters for use in reservoir simulators have been identified. The first is the numerical modeling of Stoke's flow in fracture networks, and the second uses a statistical model of a fracture distribution that allows for the calculation of the elastic properties and permeability tensor of the resulting equivalent medium. These approaches will be compared in the coming year. Multiple meetings have been held with our industry partner, Shell Oil, to identify a field test site for the project. We are focusing our efforts on a fractured carbonate field. The field application test site selection and data transfer will be completed in the coming year.

  18. Seismic Fracture Characterization Methods for Enhanced Geothermal...

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    Seismic Fracture Characterization Methods for Enhanced Geothermal Systems; 2010 Geothermal Technology Program Peer Review Report Seismic Fracture Characterization Methods for ...

  19. Microearthquake Technology for EGS Fracture Characterization...

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    Microearthquake Technology for EGS Fracture Characterization; 2010 Geothermal Technology Program Peer Review Report Microearthquake Technology for EGS Fracture Characterization; ...

  20. Fractured rock aquifer tests in the Western Siberian Basin, Ozyorsk, Russia

    SciTech Connect (OSTI)

    Nichols, R.L.; Looney, B.B.; Eddy-Dilek, C.A.

    1997-10-01

    A series of multi-zone pumping tests was conducted in a contaminated fractured rock aquifer in the Western Siberian Basin, Ozyorsk, Russia. The tests were conducted adjacent to the Mishelyak River floodplain in fractured Paleozoic porphyrites, tufts, tuff breccia, and lava typical of the Ural mountain complex. Geophysical logs, borehole photography, core samples, and results from previous borehole contamination studies were used to identify the zones to be tested. A network of three uncased wells was tested using a system of inflatable packers, pressure transducers and data loggers. Seven zones were isolated and monitored in two of the uncased wells. A straddle packer assembly was used to isolate individual zones within the pumping well. Eight constant rate pumping tests were conducted. Results of the testing indicate that shallow groundwater migrates primarily in two intervals that are separated by an interval with low lateral conductivity. The water bearing intervals have moderate to high specific capacities (1.3 and 30 L/min/m). Several processes are responsible for fracturing present in the lower interval. The network of compound fractures produced a complex array of fracture intersections yielding a fractured media with hydraulic behavior similar to porous media. Models used for the analysis of pumping tests in porous media provide a good estimation of the hydraulic response of the lower interval to pumping. Future work will include more complex analysis of the data to determine hydraulic conductivity ellipses.

  1. Infiltration into Fractured Bedrock

    SciTech Connect (OSTI)

    Salve, Rohit; Ghezzehei, Teamrat A.; Jones, Robert

    2007-09-01

    One potential consequence of global climate change and rapid changes in land use is an increased risk of flooding. Proper understanding of floodwater infiltration thus becomes a crucial component of our preparedness to meet the environmental challenges of projected climate change. In this paper, we present the results of a long-term infiltration experiment performed on fractured ash flow tuff. Water was released from a 3 x 4 m{sup 2} infiltration plot (divided into 12 square subplots) with a head of {approx}0.04 m, over a period of {approx}800 days. This experiment revealed peculiar infiltration patterns not amenable to current infiltration models, which were originally developed for infiltration into soils over a short duration. In particular, we observed that in part of the infiltration plot, the infiltration rate abruptly increased a few weeks into the infiltration tests. We suggest that these anomalies result from increases in fracture permeability during infiltration, which may be caused by swelling of clay fillings and/or erosion of infill debris. Interaction of the infiltration water with subsurface natural cavities (lithophysal cavities) could also contribute to such anomalies. This paper provides a conceptual model that partly describes the observed infiltration patterns in fractured rock and highlights some of the pitfalls associated with direct extension of soil infiltration models to fractured rock over a long period.

  2. Injection through fractures

    SciTech Connect (OSTI)

    Johns, R.A.

    1987-05-01

    Tracer tests are conducted in geothermal reservoirs as an aid in forecasting thermal breakthrough of reinjection water. To interpret tracer tests, mathematical models have been developed based on the various transport mechanisms in these highly fractured reservoirs. These tracer flow models have been applied to interpret field tests. The resulting matches between the model and field data were excellent and the model parameters were used to estimate reservoir properties. However, model fitting is an indirect process and the model's ability to estimate reservoir properties cannot be judged solely on the quality of the match between field data and model predictions. The model's accuracy in determining reservoir characteristics must be independently verified in a closely controlled environment. In this study, the closely controlled laboratory environment was chosen to test the validity and accuracy of tracer flow models developed specifically for flow in fractured rocks. The laboratory tracer tests were performed by flowing potassium iodide (KI) through artificially fractured core samples. The tracer test results were then analyzed with several models to determine which best fit the measured data. A Matrix Diffusion model was found to provide the best match of the tracer experiments. The core properties, as estimated by the Matrix Diffusion model parameters generated from the indirect matching process, were then determined. These calculated core parameters were compared to the measured core properties and were found to be in agreement. This verifies the use of the Matrix Diffusion flow model in estimating fracture widths from tracer tests.

  3. Use of integrated geologic and geophysical information for characterizing the structure of fracture systems at the US/BK Site, Grimsel Laboratory, Switzerland

    SciTech Connect (OSTI)

    Martel, S.J.; Peterson, J.E. Jr. )

    1990-05-01

    Fracture systems form the primary fluid flow paths in a number of rock types, including some of those being considered for high level nuclear waste repositories. In some cases, flow along fractures must be modeled explicitly as part of a site characterization effort. Fractures commonly are concentrated in fracture zones, and even where fractures are seemingly ubiquitous, the hydrology of a site can be dominated by a few discrete fracture zones. We have implemented a site characterization methodology that combines information gained from geophysical and geologic investigations. The general philosophy is to identify and locate the major fracture zones, and then to characterize their systematics. Characterizing the systematics means establishing the essential and recurring patterns in which fractures are organized within the zones. We make a concerted effort to use information on the systematics of the fracture systems to link the site-specific geologic, borehole and geophysical information. This report illustrates how geologic and geophysical information on geologic heterogeneities can be integrated to guide the development of hydrologic models. The report focuses on fractures, a particularly common type of geologic heterogeneity. However, many aspects of the methodology we present can be applied to other geologic heterogeneities as well. 57 refs., 40 figs., 1 tab.

  4. Inverter Ground Fault Overvoltage Testing

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Inverter Ground Fault Overvoltage Testing Andy Hoke, Austin Nelson, and Sudipta Chakraborty National Renewable Energy Laboratory Justin Chebahtah, Trudie Wang, and Michael McCarty SolarCity Corporation Technical Report NREL/TP-5D00-64173 August 2015 NREL is a national laboratory of the U.S. Department of Energy Office of Energy Efficiency & Renewable Energy Operated by the Alliance for Sustainable Energy, LLC This report is available at no cost from the National Renewable Energy Laboratory

  5. Inverter Ground Fault Overvoltage Testing

    SciTech Connect (OSTI)

    Hoke, Andy; Nelson, Austin; Chakraborty, Sudipta; Chebahtah, Justin; Wang, Trudie; McCarty, Michael

    2015-08-12

    This report describes testing conducted at NREL to determine the duration and magnitude of transient overvoltages created by several commercial PV inverters during ground fault conditions. For this work, a test plan developed by the Forum on Inverter Grid Integration Issues (FIGII) has been implemented in a custom test setup at NREL. Load rejection overvoltage test results were reported previously in a separate technical report.

  6. CONTROL AND FAULT DETECTOR CIRCUIT

    DOE Patents [OSTI]

    Winningstad, C.N.

    1958-04-01

    A power control and fault detectcr circuit for a radiofrequency system is described. The operation of the circuit controls the power output of a radio- frequency power supply to automatically start the flow of energizing power to the radio-frequency power supply and to gradually increase the power to a predetermined level which is below the point where destruction occurs upon the happening of a fault. If the radio-frequency power supply output fails to increase during such period, the control does not further increase the power. On the other hand, if the output of the radio-frequency power supply properly increases, then the control continues to increase the power to a maximum value. After the maximumn value of radio-frequency output has been achieved. the control is responsive to a ''fault,'' such as a short circuit in the radio-frequency system being driven, so that the flow of power is interrupted for an interval before the cycle is repeated.

  7. CHARACTERIZATION OF IN-SITU STRESS AND PERMEABILITY IN FRACTURED RESERVOIRS

    SciTech Connect (OSTI)

    Daniel R. Burns; M. Nafi Toksoz

    2004-07-19

    Expanded details and additional results are presented on two methods for estimating fracture orientation and density in subsurface reservoirs from scattered seismic wavefield signals. In the first, fracture density is estimated from the wavenumber spectra of the integrated amplitudes of the scattered waves as a function of offset in pre-stack data. Spectral peaks correctly identified the 50m, 35m, and 25m fracture spacings from numerical model data using a 40Hz source wavelet. The second method, referred to as the Transfer Function-Scattering Index Method, is based upon observations from 3D finite difference modeling that regularly spaced, discrete vertical fractures impart a ringing coda-type signature to any seismic energy that is transmitted through or reflected off of them. This coda energy is greatest when the acquisition direction is parallel to the fractures, the seismic wavelengths are tuned to the fracture spacing, and when the fractures have low stiffness. The method uses surface seismic reflection traces to derive a transfer function, which quantifies the change in an apparent source wavelet propagating through a fractured interval. The transfer function for an interval with low scattering will be more spike-like and temporally compact. The transfer function for an interval with high scattering will ring and be less temporally compact. A Scattering Index is developed based on a time lag weighting of the transfer function. When a 3D survey is acquired with a full range of azimuths, the Scattering Index allows the identification of subsurface areas with high fracturing and the orientation (or strike) of those fractures. The method was calibrated with model data and then applied to field data from a fractured reservoir giving results that agree with known field measurements. As an aid to understanding the scattered wavefield seen in finite difference models, a series of simple point scatterers was used to create synthetic seismic shot records collected over regular, discrete, vertical fracture systems. The model contains a series of point scatterers delineating the top tip and bottom tip of each vertical fracture. When the shot record is located in the middle of the fractured zone and oriented normal to the direction of fracturing, a complicated series of beating is observed in the back scattered energy. When the shot record is oriented parallel to the fracturing, ringing wavetrains are observed with moveouts similar to reflections from many horizontal layers. These results are consistent with the full 3D elastic modeling results. An AVOA analysis method was refined and applied to a field data set. An iterative, nonlinear least squares inversion that uses the Gauss-Newton method and analyzes the full range of azimuths simultaneously was employed. Resulting fracture location and strike orientation estimates are consistent with other fracture information from the area. Two modeling approaches for estimating permeability values from seismically derived fracture parameters have been investigated. The first is a statistical method that calculates the permeability tensor for a given distribution of fractures. A possible workflow using this method was tested on fracture distributions obtained from the Transfer Function-Scattering Index analysis method. Fracture aperture and length estimates are needed for this method. The second method is a direct flow model of discrete fractures and fracture networks using a computational fluid dynamics code. This tool provides a means of visualizing flow in fracture networks and comparing expressions for equivalent fracture aperture flow to the actual flow. A series of two dimensional models of fractures and fracture networks, as well as a 3-D model of a single rough fracture, were tested.

  8. Aerial photographic interpretation of lineaments and faults in late cenozoic deposits in the Eastern part of the Benton Range 1:100,000 quadrangle and the Goldfield, Last Chance Range, Beatty, and Death Valley Junction 1:100,000 quadrangles, Nevada and California

    SciTech Connect (OSTI)

    Reheis, M.C.; Noller, J.S.

    1991-09-01

    Lineaments and faults in Quaternary and late Tertiary deposits in the southern part of the Walker Lane are potentially active and form patterns that are anomalous with respect to the typical fault patterns in most of the Great Basin. Little work has been done to identify and characterize these faults, with the exception of those in the Death Valley-Furnace Creek (DVFCFZ) fault system and those in and near the Nevada Test Site. Four maps at a scale of 1:100,000 summarize the existing knowledge about these lineaments and faults based on extensive aerial-photo interpretation, limited field investigations, and published geologic maps. The lineaments and faults in all four maps can be divided geographically into two groups. The first group includes west- to north-trending lineaments and faults associated with the DVFCFZ and with the Pahrump fault zone in the Death Valley Junction quadrangle. The second group consists of north- to east-northeast-trending lineaments and faults in a broad area that lies east of the DVFCFZ and north of the Pahrump fault zone. Preliminary observations of the orientations and sense of slip of the lineaments and faults suggest that the least principle stress direction is west-east in the area of the first group and northwest-southeast in the area of the second group. The DVFCFZ appears to be part of a regional right-lateral strike-slip system. The DVFCFZ steps right, accompanied by normal faulting in an extensional zone, to the northern part of the Walker Lane a the northern end of Fish Lake Valley (Goldfield quadrangle), and appears to step left, accompanied by faulting and folding in a compressional zone, to the Pahrump fault zone in the area of Ash Meadows (Death Valley Junction quadrangle). 25 refs.

  9. Fault Intersection | Open Energy Information

    Open Energy Info (EERE)

    Tectonic Setting Host Rock Age Host Rock Lithology Mean Capacity Mean Reservoir Temp Bac-Man Laguna Geothermal Area Philippine Island Arc Subduction Zone Volcanic 150 MW150,000 kW...

  10. Proceedings of the International Symposium on Dynamics of Fluids in Fractured Rocks: Concepts and Recent Advances

    SciTech Connect (OSTI)

    Faybishenko, B.

    1999-02-01

    This publication contains extended abstracts of papers presented at the International Symposium ''Dynamics of Fluids in Fractured Rocks: Concepts and Recent Advances'' held at Ernest Orlando Lawrence Berkeley National Laboratory on February 10-12, 1999. This Symposium is organized in Honor of the 80th Birthday of Paul A. Witherspoon, who initiated some of the early investigations on flow and transport in fractured rocks at the University of California, Berkeley, and at Lawrence Berkeley National Laboratory. He is a key figure in the development of basic concepts, modeling, and field measurements of fluid flow and contaminant transport in fractured rock systems. The technical problems of assessing fluid flow, radionuclide transport, site characterization, modeling, and performance assessment in fractured rocks remain the most challenging aspects of subsurface flow and transport investigations. An understanding of these important aspects of hydrogeology is needed to assess disposal of nu clear wastes, development of geothermal resources, production of oil and gas resources, and remediation of contaminated sites. These Proceedings of more than 100 papers from 12 countries discuss recent scientific and practical developments and the status of our understanding of fluid flow and radionuclide transport in fractured rocks. The main topics of the papers are: Theoretical studies of fluid flow in fractured rocks; Multi-phase flow and reactive chemical transport in fractured rocks; Fracture/matrix interactions; Hydrogeological and transport testing; Fracture flow models; Vadose zone studies; Isotopic studies of flow in fractured systems; Fractures in geothermal systems; Remediation and colloid transport in fractured systems; and Nuclear waste disposal in fractured rocks.

  11. Phase Field Fracture Mechanics.

    SciTech Connect (OSTI)

    Robertson, Brett Anthony

    2015-11-01

    For this assignment, a newer technique of fracture mechanics using a phase field approach, will be examined and compared with experimental data for a bend test and a tension test. The software being used is Sierra Solid Mechanics, an implicit/explicit finite element code developed at Sandia National Labs in Albuquerque, New Mexico. The bend test experimental data was also obtained at Sandia Labs while the tension test data was found in a report online from Purdue University.

  12. Dependence of dynamic fracture resistance on crack velocity in tungsten: Pt. 1. Single crystals

    SciTech Connect (OSTI)

    Liv, J.M.; Shen, B.W.

    1984-06-01

    The dependence of dynamic fracture resistance on crack propagation velocity on (100) in tungsten has been examined. A correlation is obtained between the measured local crack velocity with the surfac and subsurface deformations. Based on the experimental results on one pass, two passes, and prestrained, electron beam zone refined single crystals, a discussion is given on the slip modes activated at the crack tip, the contributions to the dynamic fracture resistance from dislocations and surface features and from the preexisting deformed microstructure.

  13. Zoning and Permitting Resources

    Broader source: Energy.gov [DOE]

    Zoning and permitting is commonly controlled by local governments and may be applicable to both residential and commercial properties.

  14. Fault-tolerant dynamic task graph scheduling

    SciTech Connect (OSTI)

    Kurt, Mehmet C.; Krishnamoorthy, Sriram; Agrawal, Kunal; Agrawal, Gagan

    2014-11-16

    In this paper, we present an approach to fault tolerant execution of dynamic task graphs scheduled using work stealing. In particular, we focus on selective and localized recovery of tasks in the presence of soft faults. We elicit from the user the basic task graph structure in terms of successor and predecessor relationships. The work stealing-based algorithm to schedule such a task graph is augmented to enable recovery when the data and meta-data associated with a task get corrupted. We use this redundancy, and the knowledge of the task graph structure, to selectively recover from faults with low space and time overheads. We show that the fault tolerant design retains the essential properties of the underlying work stealing-based task scheduling algorithm, and that the fault tolerant execution is asymptotically optimal when task re-execution is taken into account. Experimental evaluation demonstrates the low cost of recovery under various fault scenarios.

  15. Procedure for estimating fracture energy from fracture surface roughness

    DOE Patents [OSTI]

    Williford, Ralph E.

    1989-01-01

    The fracture energy of a material is determined by first measuring the length of a profile of a section through a fractured surface of the material taken on a plane perpendicular to the mean plane of that surface, then determining the fractal dimensionality of the surface. From this, the yield strength of the material, and the Young's Modulus of that material, the fracture energy is calculated.

  16. Geologic Assessment of the Damage Zone from the Second Test at Source Physics Experiment-Nevada (SPE-N)

    SciTech Connect (OSTI)

    Townsend, M. J.; Huckins-Gang, H. E.; Prothro, L. B.; Reed, D. N.

    2012-12-01

    The National Center for Nuclear Security, established by the U.S. Department of Energy, National Nuclear Security Administration (NNSA), is conducting a series of explosive tests at the Nevada National Security Site that are designed to increase the understanding of certain basic physical phenomena associated with underground explosions. These tests will aid in developing technologies that might be used to detect underground nuclear explosions in support of verification activities for the Comprehensive Nuclear-Test-Ban Treaty. The initial project is a series of explosive tests, known collectively as the Source Physics Experiment-Nevada (SPE-N), being conducted in granitic rocks. The SPE-N test series is designed to study the generation and propagation of seismic waves. The results will help advance the seismic monitoring capability of the United States by improving the predictive capability of physics-based modeling of explosive phenomena. The first SPE N (SPE-N-1) test was conducted in May 2011, using 100 kg of explosives at the depth of 54.9 m in the U 15n source hole. SPE-N-2 was conducted in October 2011, using 1,000 kg of explosives at the depth of 45.7 m in the same source hole. The SPE-N-3 test was conducted in the same source hole in July 2012, using the same amount and type of explosive as for SPE-N-2, and at the same depth as SPE-N-2, within the damage zone created by the SPE-N-2 explosion to investigate damage effects on seismic wave propagation. Following the SPE-N-2 shot and prior to the SPE-N-3 shot, the core hole U-15n#10 was drilled at an angle from the surface to intercept the SPE-N-2 shot point location to obtain information necessary to characterize the damage zone. The objective was to determine the position of the damage zone near the shot point, at least on the northeast, where the core hole penetrated it, and obtain information on the properties of the damaged medium. Geologic characterization of the post-SPE-N-2 core hole included geophysical logging, a directional survey, and geologic description of the core to document visual evidence of damage. Selected core samples were provided to Sandia National Laboratories (SNL) for measurement of physical and mechanical properties. A video was also run in the source hole after it was cleaned out. A significant natural fault zone was encountered in the angle core hole between 5.7 and 7.5 m from the shot point. However, several of the fractures observed in the core hole are interpreted as having been caused by the explosion. The fractures are characterized by a fresh, mechanically broken look, with uncoated and very irregular surfaces. They tend to terminate against natural fractures and have orientations that differ from the previously defined natural fracture sets; they are common starting at about 5.4 m from the shot point. Within about 3.3 m of the shot point to the end of the recovered core at 1.6 m from the shot point, some of the core samples are softer and lighter in color, but do not appear to be weathered. It is thought this could be indicative of the presence of distributed microfracturing.

  17. Sandia Energy - PV Arc-Fault and Ground Fault Detection and Mitigation...

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    prescribe maintenance schedules, and warn of arc-fault events. Investigating the proscons of module-level, string-level, and array-level arc-fault detection schemes....

  18. Hydrogen-Assisted Fracture: Materials Testing and Variables Governing...

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    Hydrogen-Assisted Fracture: Materials Testing and Variables Governing Fracture Hydrogen-Assisted Fracture: Materials Testing and Variables Governing Fracture SNL has 40+ years ...

  19. Efficient Synchronization Stability Metrics for Fault Clearing...

    Office of Scientific and Technical Information (OSTI)

    Title: Efficient Synchronization Stability Metrics for Fault Clearing Authors: Backhaus, Scott N. 1 ; Chertkov, Michael 1 ; Bent, Russell Whitford 1 ; Bienstock, Daniel 2...

  20. Reducing the Risk of Arc-Faults

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    arc-fault detection algorithms by: 1. Performing arcing tests at the Distributed Energy Technologies Laboratory (DETL) with AFCI prototypes to verify their functionality on...

  1. INNOVATIVE METHODOLOGY FOR DETECTION OF FRACTURE-CONTROLLED SWEET SPOTS IN THE NORTHERN APPALACHIAN BASIN

    SciTech Connect (OSTI)

    Robert Jacobi; John Fountain

    2001-02-28

    In the structure task, we completed a N-S transect east of Seneca Lake that indicated a N-striking fault near the southeastern shore of Seneca Lake, and also indicated NE and ENE-trending FIDs and faults north of Valois. The orientation and existence of the NE-striking FIDs and faults are thought to be controlled by basement faults, rather than thrust ramps above the Salina salt controlled only by a far-field Alleghanian stress field. Structure contour maps based on well log analyses have been constructed but not interpreted. Soil gas data displayed a number of ethane-charged soil gas ''spikes'' on a N-S transect from Ovid south to near Valois. The soil gas team found a larger number of spikes in the northern half of the survey, suggesting more open fractures (and faults) in the northern half of the survey. Seismic data has been purchased and reprocessed. Several grabens observed in the Trenton reflector are consistent with surface structure, soil gas, and aeromagnetic anomalies. The aeromagnetic survey is completed and the data is processed. Prominent magnetic anomalies suggest that faults in the Precambrian basement are located beneath regions where grabens in the Trenton are located.

  2. Fracture mapping in geothermal fields with long-offset induction logging

    SciTech Connect (OSTI)

    Wilt, M.; Takasugi, Shinji; Uchida, Toshihiro; Kasameyer, P.; Lee, Ki Ha; Lippmann, M.

    1997-01-01

    The mapping of producing fractures in a geothermal field is an important technical objective in field development. Locating, orientating, and assessing producing fractures can guide drilling programs and optimize the placement of production and injection wells. A long-offset multicomponent borehole induction resistivity tool capable of surviving the high temperatures encountered in geothermal wells has recently been developed and tested in a high temperature environment. Several characteristics of this device make it ideal for detecting producing fractures. Whereas commercial induction logging devices have strong source-receiver separations of 1 m, this device has multiple sensors with separation of 8 m, allowing for deeper penetrations and the ability to straddle fracture-induced washout zones in boreholes. The three-component measurements also make it possible to map the strike and inclination of nearby fractures and other three-dimensional structures. This in turn allows for accurate projection of these structures into the space between wells.

  3. Hydrothermally altered and fractured granite as an HDR reservoir in the EPS-1 borehole, Alsace,

    SciTech Connect (OSTI)

    Genter, A.; Traineau, H.

    1992-01-01

    As part of the European Hot Dry Rocks Project, a second exploration borehole, EPS-1, has been cored to a depth of 2227 m at Soultz-sous-Forets (France). The target was a granite beginning at 1417 m depth, overlain by post-Paleozoic sedimentary cover. Structural analysis and petrographic examination of the 800-m porphyritic granite core, have shown that this rock has undergone several periods of hydrothermal alteration and fracturing. More than 3000 natural structures were recorded, whose distribution pattern shows clusters where low-density fracture zones (less than 1 per meter) alternate with zones of high fracture density (more than 20 per meter). Vein alteration, ascribed to paleohydrothermal systems, developed within the hydrothermally altered and highly fractured zones, transforming primary biotite and plagioclase into clay minerals. One of these zones at 2.2 km depth produced a hot-water outflow during coring, indicating the existence of a hydrothermal reservoir. Its permeability is provided by the fracture network and by secondary porosity of the granitic matrix resulting from vein alteration. This dual porosity in the HDR granite reservoir must be taken into account in the design of the heat exchanger, both for modeling the water-rock interactions and for hydraulic testing.

  4. FRACTURE ENHANCED SOIL VAPOR EXTRACTION TECHNOLOGY DEMONSTRATION AT THE A-014 OUTFALL

    SciTech Connect (OSTI)

    Riha, B; Warren Hyde, W; Richard Hall , R

    2008-03-12

    Data collected during this study show that the performance of hydraulically fractured wells (with respect to mass removal rates) may tend to decrease with time following precipitation events. These effects are due to temporary increases in water saturation in the formation within the vicinity of the fractures, therefore, the wells should tend to rebound during subsequent dry periods. The data available for fractured well versus conventional well performance (with respect to flow rate versus vacuum pressure) are limited in this study. However, the data that we have to draw from suggest that, with the possible exception of a few extreme examples, hydraulically fractured wells tend to perform better than conventional wells during soil vapor extraction (SVE) operation at the A-14 Outfall. The pancake like geometry associated with hydraulic fractures also leads to a significant increase in zone of influence (ZOI), as compared to conventional wells. The increase in ZOI is due to the radially extending, horizontal, high-permeability conduit nature of the hydraulic fracture, however, air-flow into the fracture is predominately vertical (occurring at right angles to the fracture plane). Flow rates from above and below the fracture will tend to be equivalent when the formation is homogeneous, however, in the case of directionally fining depositional sequences flow rates will be greater from the direction of increasing permeability. The Upland Unit is a fining upward sequence, therefore flow rates (and contaminant mass flow rates) will tend to be higher below the fracture. This suggests that emplacing the fractures slightly above the source zone is an important strategy for accelerating contaminant removal at the A-014 Outfall site and in the Upland Unit at the SRS. However, due to the multitude of previous borings at the A-014 Outfall site, the shallower fractures failed. More than 2500 lbs of chlorinated volatile organic compounds (cVOCs) were removed during approximately 6 months of fractured well SVE operation at the A-014 field site. Plotting total mass removed over this time period shows a roughly linear relationship Figure 7. This occurs because the mass removal rate remains fairly constant with time. When mass removal comes predominately from cVOCs stored in the vapor phase there is a marked decline in mass removal rate over a short period of time due to the limiting nature of diffusion. Constant mass removal rates suggest that a source zone has been directly targeted and, therefore, is providing a constant supply of cVOC that partitions into the vapor phase and is removed through the well. Directly targeting and removing source zones is the most efficient approach to remediating contaminated sites. Results of this study show that utilization of hydraulic fractures during SVE is an effective approach for increasing remediation efficiency at the A-014 Outfall field site and in the Upland Unit at the SRS. Hydraulically fractured wells tend to produce greater flow rates and create larger ZOI's than do conventional wells. These attributes allow fractured wells to effectively treat larger volumes of formation. The unique sand-emplacement geometry associated with hydraulically fractured wells also allows direct targeting of multiple zones located at similar elevations within a fairly large radius of the well. The ability to directly target source zones significantly decreases diffusion pathways, therefore, significantly decreasing the time required to reach remediation goals.

  5. Method for selectively orienting induced fractures in subterranean earth formations

    DOE Patents [OSTI]

    Shuck, Lowell Z.

    1977-02-01

    The orientation of hydraulically-induced fractures in relatively deep subterranean earth formations is normally confined to vertical projections along a plane parallel to the maximum naturally occurring (tectonic) compressive stress field. It was found that this plane of maximum compressive stress may be negated and, in effect, re-oriented in a plane projecting generally orthogonal to the original tectonic stress plane by injecting liquid at a sufficiently high pressure into a wellbore fracture oriented in a plane parallel to the plane of tectonic stress for the purpose of stressing the surrounding earth formation in a plane generally orthogonal to the plane of tectonic stress. With the plane of maximum compressive stress re-oriented due to the presence of the induced compressive stress, liquid under pressure is injected into a second wellbore disposed within the zone influenced by the induced compressive stress but at a location in the earth formation laterally spaced from the fracture in the first wellbore for effecting a fracture in the second wellbore along a plane generally orthogonal to the fracture in the first wellbore.

  6. Modeling the Fracture of Ice Sheets on Parallel Computers

    SciTech Connect (OSTI)

    Waisman, Haim; Tuminaro, Ray

    2013-10-10

    The objective of this project was to investigate the complex fracture of ice and understand its role within larger ice sheet simulations and global climate change. This objective was achieved by developing novel physics based models for ice, novel numerical tools to enable the modeling of the physics and by collaboration with the ice community experts. At the present time, ice fracture is not explicitly considered within ice sheet models due in part to large computational costs associated with the accurate modeling of this complex phenomena. However, fracture not only plays an extremely important role in regional behavior but also influences ice dynamics over much larger zones in ways that are currently not well understood. To this end, our research findings through this project offers significant advancement to the field and closes a large gap of knowledge in understanding and modeling the fracture of ice sheets in the polar regions. Thus, we believe that our objective has been achieved and our research accomplishments are significant. This is corroborated through a set of published papers, posters and presentations at technical conferences in the field. In particular significant progress has been made in the mechanics of ice, fracture of ice sheets and ice shelves in polar regions and sophisticated numerical methods that enable the solution of the physics in an efficient way.

  7. NETL Releases Hydraulic Fracturing Study

    Broader source: Energy.gov [DOE]

    The National Energy Technology Laboratory has released a technical report on the results of a limited field study that monitored a hydraulic fracturing operation in Greene County, PA.

  8. MULTI-ATTRIBUTE SEISMIC/ROCK PHYSICS APPROACH TO CHARACTERIZING FRACTURED RESERVOIRS

    SciTech Connect (OSTI)

    Gary Mavko

    2000-10-01

    This project consists of three key interrelated Phases, each focusing on the central issue of imaging and quantifying fractured reservoirs, through improved integration of the principles of rock physics, geology, and seismic wave propagation. This report summarizes the results of Phase I of the project. The key to successful development of low permeability reservoirs lies in reliably characterizing fractures. Fractures play a crucial role in controlling almost all of the fluid transport in tight reservoirs. Current seismic methods to characterize fractures depend on various anisotropic wave propagation signatures that can arise from aligned fractures. We are pursuing an integrated study that relates to high-resolution seismic images of natural fractures to the rock parameters that control the storage and mobility of fluids. Our goal is to go beyond the current state-of-the art to develop and demonstrate next generation methodologies for detecting and quantitatively characterizing fracture zones using seismic measurements. Our study incorporates 3 key elements: (1) Theoretical rock physics studies of the anisotropic viscoelastic signatures of fractured rocks, including up scaling analysis and rock-fluid interactions to define the factors relating fractures in the lab and in the field. (2) Modeling of optimal seismic attributes, including offset and azimuth dependence of travel time, amplitude, impedance and spectral signatures of anisotropic fractured rocks. We will quantify the information content of combinations of seismic attributes, and the impact of multi-attribute analyses in reducing uncertainty in fracture interpretations. (3) Integration and interpretation of seismic, well log, and laboratory data, incorporating field geologic fracture characterization and the theoretical results of items 1 and 2 above. The focal point for this project is the demonstration of these methodologies in the Marathon Oil Company Yates Field in West Texas.

  9. Modeling brittle fracture, slip weakening, and variable friction in geomaterials with an embedded strong discontinuity finite element.

    SciTech Connect (OSTI)

    Regueiro, Richard A.; Borja, R. I.; Foster, C. D.

    2006-10-01

    Localized shear deformation plays an important role in a number of geotechnical and geological processes. Slope failures, the formation and propagation of faults, cracking in concrete dams, and shear fractures in subsiding hydrocarbon reservoirs are examples of important effects of shear localization. Traditional engineering analyses of these phenomena, such as limit equilibrium techniques, make certain assumptions on the shape of the failure surface as well as other simplifications. While these methods may be adequate for the applications for which they were designed, it is difficult to extrapolate the results to more general scenarios. An alternative approach is to use a numerical modeling technique, such as the finite element method, to predict localization. While standard finite elements can model a wide variety of loading situations and geometries quite well, for numerical reasons they have difficulty capturing the softening and anisotropic damage that accompanies localization. By introducing an enhancement to the element in the form of a fracture surface at an arbitrary position and orientation in the element, we can regularize the solution, model the weakening response, and track the relative motion of the surfaces. To properly model the slip along these surfaces, the traction-displacement response must be properly captured. This report focuses on the development of a constitutive model appropriate to localizing geomaterials, and the embedding of this model into the enhanced finite element framework. This modeling covers two distinct phases. The first, usually brief, phase is the weakening response as the material transitions from intact continuum to a body with a cohesionless fractured surface. Once the cohesion has been eliminated, the response along the surface is completely frictional. We have focused on a rate- and state-dependent frictional model that captures stable and unstable slip along the surface. This model is embedded numerically into the element using a generalized trapezoidal formulation. While the focus is on the constitutive model of interest, the framework is also developed for a general surface response. This report summarizes the major research and development accomplishments for the LDRD project titled 'Cohesive Zone Modeling of Failure in Geomaterials: Formulation and Implementation of a Strong Discontinuity Model Incorporating the Effect of Slip Speed on Frictional Resistance'. This project supported a strategic partnership between Sandia National Laboratories and Stanford University by providing funding for the lead author, Craig Foster, during his doctoral research.

  10. Crossing Active Faults on the Sakhalin II Onshore Pipeline Route: Pipeline Design and Risk Analysis

    SciTech Connect (OSTI)

    Mattiozzi, Pierpaolo; Strom, Alexander

    2008-07-08

    Twin oil (20 and 24 inch) and gas (20 and 48 inch) pipeline systems stretching 800 km are being constructed to connect offshore hydrocarbon deposits from the Sakhalin II concession in the North to an LNG plant and oil export terminal in the South of Sakhalin island. The onshore pipeline route follows a regional fault zone and crosses individual active faults at 19 locations. Sakhalin Energy, Design and Construction companies took significant care to ensure the integrity of the pipelines, should large seismic induced ground movements occur during the Operational life of the facilities. Complex investigations including the identification of the active faults, their precise location, their particular displacement values and assessment of the fault kinematics were carried out to provide input data for unique design solutions. Lateral and reverse offset displacements of 5.5 and 4.5 m respectively were determined as the single-event values for the design level earthquake (DLE) - the 1000-year return period event. Within the constraints of a pipeline route largely fixed, the underground pipeline fault crossing design was developed to define the optimum routing which would minimize stresses and strain using linepipe materials which had been ordered prior to the completion of detailed design, and to specify requirements for pipe trenching shape, materials, drainage system, etc. Detailed Design was performed with due regard to actual topography and to avoid the possibility of the trenches freezing in winter, the implementation of specific drainage solutions and thermal protection measures.

  11. Crossing Active Faults on the Sakhalin II Onshore Pipeline Route: Analysis Methodology and Basic Design

    SciTech Connect (OSTI)

    Vitali, Luigino; Mattiozzi, Pierpaolo

    2008-07-08

    Twin oil (20 and 24 inch) and gas (20 and 48 inch) pipeline systems stretching 800 km are being constructed to connect offshore hydrocarbon deposits from the Sakhalin II concession in the North to an LNG plant and oil export terminal in the South of Sakhalin island. The onshore pipeline route follows a regional fault zone and crosses individual active faults at 19 locations. Sakhalin Energy, Design and Construction companies took significant care to ensure the integrity of the pipelines, should large seismic induced ground movements occur during the Operational life of the facilities. Complex investigations including the identification of the active faults, their precise location, their particular displacement values and assessment of the fault kinematics were carried out to provide input data for unique design solutions. Lateral and reverse offset displacements of 5.5 and 4.5 m respectively were determined as the single-event values for the design level earthquake (DLE)--the 1000-year return period event. Within the constraints of a pipeline route largely fixed, the underground pipeline fault crossing design was developed to define the optimum routing which would minimize stresses and strain using linepipe materials which had been ordered prior to the completion of detailed design, and to specify requirements for pipe trenching shape, materials, drainage system, etc. This Paper describes the steps followed to formulate the concept of the special trenches and the analytical characteristics of the Model.

  12. Self-triggering superconducting fault current limiter

    DOE Patents [OSTI]

    Yuan, Xing; Tekletsadik, Kasegn

    2008-10-21

    A modular and scaleable Matrix Fault Current Limiter (MFCL) that functions as a "variable impedance" device in an electric power network, using components made of superconducting and non-superconducting electrically conductive materials. The matrix fault current limiter comprises a fault current limiter module that includes a superconductor which is electrically coupled in parallel with a trigger coil, wherein the trigger coil is magnetically coupled to the superconductor. The current surge doing a fault within the electrical power network will cause the superconductor to transition to its resistive state and also generate a uniform magnetic field in the trigger coil and simultaneously limit the voltage developed across the superconductor. This results in fast and uniform quenching of the superconductors, significantly reduces the burnout risk associated with non-uniformity often existing within the volume of superconductor materials. The fault current limiter modules may be electrically coupled together to form various "n" (rows).times."m" (columns) matrix configurations.

  13. PSU CBEI: VOLTTRON Compatible and Cost-Effective Fault Diagnostic...

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    of cost-effective fault detection and diagnosis strategies for air handling unit (AHU) ... control company, service company, fault diagnosis company 2 Purpose and Objectives Problem ...

  14. Fault Current Limiters (FCL) Fact Sheet | Department of Energy

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    Fault Current Limiters (FCL) Fact Sheet Fault Current Limiters (FCL) Fact Sheet Plugging America Into the Future of Power: Superconducting & Solid-state Power Equipment What are ...

  15. Termination of a Major Normal Fault | Open Energy Information

    Open Energy Info (EERE)

    sometimes split into multiple closely-spaced faults that result in increased permeability. Fault sets at these terminations sometimes appear as "horsetailing" splays that...

  16. Fault-induced delayed voltage recovery in a long inhomogeneous...

    Office of Scientific and Technical Information (OSTI)

    Journal Article: Fault-induced delayed voltage recovery in a long inhomogeneous power-distribution feeder Citation Details In-Document Search Title: Fault-induced delayed voltage ...

  17. Characterization of Fractures in Geothermal Reservoirs Using...

    Open Energy Info (EERE)

    Abstract The optimal design of production in fractured geothermal reservoirs requires knowledge of the resource's connectivity, therefore making fracture characterization highly...

  18. Correlations to predict frictional pressure loss of hydraulic-fracturing slurry in coiled tubing

    SciTech Connect (OSTI)

    Shah, S.; Zhoi, Y.X.; Bailey, M.; Hernandez, J.

    2009-08-15

    Compared with conventional-tubing fracturing, coiled-tubing (CT) fracturing has several advantages. CT fracturing has become an effective stimulation technique for multizone oil and gas wells. It is also an attractive production-enhancement method for multiseam coalbed-methane wells, and wells with bypassed zones. The excessive frictional pressure loss through CT has been a concern in fracturing. The small diameter of the string limits the cross-sectional area open to flow. Furthermore, the tubing curvature causes secondary flow and results in extra flow resistance. This increased frictional pressure loss results in high surface pumping pressure. The maximum possible pump rate and sand concentration, therefore, have to be reduced. To design a CT fracturing job properly, it is essential to predict the frictional pressure loss through the tubing accurately. This paper presents correlations for the prediction of frictional pressure loss of fracturing slurries in straight tubing and CT. They are developed on the basis of full-scale slurry-flow tests with 11/2-in. CT and slurries prepared with 35 lbm/1,000 gal of guar gel. The extensive experiments were conducted at the full-scale CT-flow test facility. The proposed correlations have been verified with the experimental data and actual field CT-fracturing data. Case studies of wells recently fractured are provided to demonstrate the application of the correlations. The correlations will be useful to the CT engineers in their hydraulics design calculations.

  19. Saturated Zone Colloid Transport

    SciTech Connect (OSTI)

    H. Viswanathan; P. Reimus

    2003-09-05

    Colloid retardation is influenced by the attachment and detachment of colloids from immobile surfaces. This analysis demonstrates the development of parameters necessary to estimate attachment and detachment of colloids and, hence, retardation in both fractured tuff and porous alluvium. Field and experimental data specific to fractured tuff are used for the analysis of colloid retardation in fractured tuff. Experimental data specific to colloid transport in alluvial material from Yucca Mountain as well as bacteriophage field studies in alluvial material, which are thought to be good analogs for colloid transport, are used to estimate attachment and detachment of colloids in the alluvial material. There are no alternative scientific approaches or technical methods for calculating these retardation factors.

  20. INNOVATAIVE METHODOLOGY FOR DETECTION OF FRACTURE-CONTROLLED SWEET SPOTS IN THE NORTHERN APPALACHIAN BASIN

    SciTech Connect (OSTI)

    Robert Jacobi; John Fountain

    2002-06-30

    In the structure task, for this reporting period, the authors also edited and revised the map that displays the modified rose diagrams for the data they collected and reduced along the east side of Seneca Lake. They also revised the N-S transect that displays the frequency of ENE-striking fractures, and constructed a new N-S transect that shows the frequency of E-striking fractures. This transect compliments the earlier transect they constructed for fracture frequency of ENE-striking fractures. Significantly, the fracture frequency transect for E-W fractures shows a spike in fracture frequency in the region of the E-striking Firtree anticline that is observed on seismic reflection sections. The ENE fracture set does not exhibit an unusually high fracture frequency in this area. In contrast, the fracture frequency of the ENE-striking set is anomalously high in the region of the Trenton/Black River grabens. They have nearly completed reducing the data they collected from a NNW-SSE transect on the west side of Cayuga Lake and they have constructed modified rose diagrams for most sites. Structure contour maps and isopach maps have been revised based on additional well log analyses. Except for the Glodes Corners Field, the well spacing generally remains insufficient to identify faults or their precise locations. However, relatively sharp elevational changes east of Keuka Lake support the contention that faults occur along the east side of Keuka Lake. Similarly, a single well east of Seneca Lake shows that the Trenton there is low compared to distant wells, based on an assumed regional slope. This same area is where one of the Trenton grabens occurs. They have completed the interpretation of the reprocessed data that Quest licensed and had reprocessed. Several grabens observed in the Trenton and Black River reflectors are consistent with surface structure, soil gas, and aeromagnetic anomalies. In this report they display all four interpreted seismic lines. These data indicate that integration of aeromagnetic and topographic lineaments, surface structure, soil gas with seismic and well logs allows them to extrapolate Trenton-Black River trends away from confirmatory seismic lines.

  1. Particle denuded zones in alumina reinforced aluminum matrix composite weldments

    SciTech Connect (OSTI)

    Chidambaram, A.; Bhole, S.D.

    1996-08-01

    The Welding Institute of Canada (WIC), Ontario, has been studying the weldability of different DURALCAN MMC`s. Research on alumina reinforced (20 vol.%) 6061 Al alloy GTA welds showed satisfactory tensile and yield strengths (0.2% Proof Stress) but the welds failed to pass the bend test requirements with fracture taking place in the relatively brittle heat affected zone (HAZ). Further, the welds were characterized by a region which was devoid of reinforcement particles adjacent to the fusion lines. The present study was undertaken to try and explain the formation of this particle denuded zone (PDZ) at the fusion lines.

  2. Mechanical Models of Fault-Related Folding

    SciTech Connect (OSTI)

    Johnson, A. M.

    2003-01-09

    The subject of the proposed research is fault-related folding and ground deformation. The results are relevant to oil-producing structures throughout the world, to understanding of damage that has been observed along and near earthquake ruptures, and to earthquake-producing structures in California and other tectonically-active areas. The objectives of the proposed research were to provide both a unified, mechanical infrastructure for studies of fault-related foldings and to present the results in computer programs that have graphical users interfaces (GUIs) so that structural geologists and geophysicists can model a wide variety of fault-related folds (FaRFs).

  3. Micro-Earthquake At Kilauea East Rift Geothermal Area (Kenedi...

    Open Energy Info (EERE)

    identify fault and fracture orientations, and locate zones of high and low velocities. Based on earthquake sizes, locations, and depths the evidence from this study suggests...

  4. ASHRAE Climate Zones | Open Energy Information

    Open Energy Info (EERE)

    navigation, search Subtype A Subtype B Subtype C Climate Zone Number 1 Zone 1A Zone 1B NA Climate Zone Number 2 Zone 2A Zone 2B NA Climate Zone Number 3 Zone 3A Zone 3B Zone...

  5. Microearthquake Technology for EGS Fracture Characterization | Department

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    of Energy Microearthquake Technology for EGS Fracture Characterization Microearthquake Technology for EGS Fracture Characterization Project objectives: To understand how EGS fracture networks develop; To develop technology to determine accurate absolute three-dimensional positions of EGS fracture networks. PDF icon seismic_foulger_microearthquake.pdf More Documents & Publications Creation of an Engineered Geothermal System through Hydraulic and Thermal Stimulation Newberry EGS

  6. PV Systems Reliability Final Technical Report: Ground Fault Detection

    SciTech Connect (OSTI)

    Lavrova, Olga; Flicker, Jack David; Johnson, Jay

    2016-01-01

    We have examined ground faults in PhotoVoltaic (PV) arrays and the efficacy of fuse, current detection (RCD), current sense monitoring/relays (CSM), isolation/insulation (Riso) monitoring, and Ground Fault Detection and Isolation (GFID) using simulations based on a Simulation Program with Integrated Circuit Emphasis SPICE ground fault circuit model, experimental ground faults installed on real arrays, and theoretical equations.

  7. Hydraulic fracturing utilizing a refractory proppant

    SciTech Connect (OSTI)

    Jennings, A.R.; Stowe, L.R.

    1990-01-01

    This patent describes a method for hydraulically fracturing a formation where a fused refractory proppant is used. It comprises: placing into a fracturing fluid a fused refractory proppant consisting essentially of silicon carbide or silicon nitride having a mohs hardness of about 9 and in an amount sufficient to prop a created fracture where the proppant is substantially crush and acid resistant; injecting into the formation the fracturing fluid with the proppant therein under a pressure sufficient to fracture the formation; and fracturing the formation and thereafter causing the pressure to be released thereby propping at least one fracture which proppant provides for increased heat transfer into the formation.

  8. RELATIVE PERMEABILITY OF FRACTURED ROCK

    Office of Scientific and Technical Information (OSTI)

    ... This hinders the creation of connected fracture networks even if the rock is subjected to ... Bergosh, J.L., Lord, G.D., 1987: "New Developments in the Analysis of Cores From Naturally ...

  9. A connecting network with fault tolerance capabilities

    SciTech Connect (OSTI)

    Ciminiera, L.; Serra, A.

    1986-06-01

    A new multistage interconnection network is presented in this paper. It is able to handle the communications between the connected devices correctly, even in the presence of fault(s) in the network. This goal is achieved by using redundant paths with a fast procedure able to dynamically reroute the message. It is also shown that the rerouting properties are still valid when broadcasting transmission is used.

  10. SATURATED ZONE IN-SITU TESTING

    SciTech Connect (OSTI)

    P.W. REIMUS

    2004-11-08

    The purpose of this scientific analysis is to document the results and interpretations of field experiments that test and validate conceptual flow and radionuclide transport models in the saturated zone (SZ) near Yucca Mountain, Nevada. The test interpretations provide estimates of flow and transport parameters used in the development of parameter distributions for total system performance assessment (TSPA) calculations. These parameter distributions are documented in ''Site-Scale Saturated Zone Flow Model (BSC 2004 [DIRS 170037]), Site-Scale Saturated Zone Transport'' (BSC 2004 [DIRS 170036]), Saturated Zone Colloid Transport (BSC 2004 [DIRS 170006]), and ''Saturated Zone Flow and Transport Model Abstraction'' (BSC 2004 [DIRS 170042]). Specifically, this scientific analysis contributes the following to the assessment of the capability of the SZ to serve as part of a natural barrier for waste isolation for the Yucca Mountain repository system: (1) The bases for selection of conceptual flow and transport models in the saturated volcanics and the saturated alluvium located near Yucca Mountain. (2) Results and interpretations of hydraulic and tracer tests conducted in saturated fractured volcanics at the C-wells complex near Yucca Mountain. The test interpretations include estimates of hydraulic conductivities, anisotropy in hydraulic conductivity, storativities, total porosities, effective porosities, longitudinal dispersivities, matrix diffusion mass transfer coefficients, matrix diffusion coefficients, fracture apertures, and colloid transport parameters. (3) Results and interpretations of hydraulic and tracer tests conducted in saturated alluvium at the Alluvial Testing Complex (ATC) located at the southwestern corner of the Nevada Test Site (NTS). The test interpretations include estimates of hydraulic conductivities, storativities, total porosities, effective porosities, longitudinal dispersivities, matrix diffusion mass transfer coefficients, and colloid transport parameters. (4) Comparisons of sorption parameter estimates for a reactive solute tracer (lithium ion) derived from the C-wells field tracer tests and laboratory tests using C-wells core samples. (5) Sorption parameter estimates for lithium ion derived from laboratory tests using alluvium samples from ATC well NC-EWDP-19D. These estimates will allow a comparison of laboratory- and field-derived sorption parameters to be made in saturated alluvium if cross-hole tracer tests are conducted at the ATC.

  11. Fracturing And Liquid CONvection

    Energy Science and Technology Software Center (OSTI)

    2012-02-29

    FALCON has been developed to enable simulation of the tightly coupled fluid-rock behavior in hydrothermal and engineered geothermal system (EGS) reservoirs, targeting the dynamics of fracture stimulation, fluid flow, rock deformation, and heat transport in a single integrated code, with the ultimate goal of providing a tool that can be used to test the viability of EGS in the United States and worldwide. Reliable reservoir performance predictions of EGS systems require accurate and robust modelingmore » for the coupled thermal-hydrological-mechanical processes. Conventionally, these types of problems are solved using operator-splitting methods, usually by coupling a subsurface flow and heat transport simulator with a solid mechanics simulator via input files. FALCON eliminates the need for using operator-splitting methods to simulate these systems, and the scalability of the underlying MOOSE architecture allows for simulating these tightly coupled processes at the reservoir scale, allowing for examination of the system as a whole (something the operator-splitting methodologies generally cannot do).« less

  12. Development of Fault Models for Hybrid Fault Detection and Diagnostics Algorithm: October 1, 2014 -- May 5, 2015

    SciTech Connect (OSTI)

    Cheung, Howard; Braun, James E.

    2015-12-31

    This report describes models of building faults created for OpenStudio to support the ongoing development of fault detection and diagnostic (FDD) algorithms at the National Renewable Energy Laboratory. Building faults are operating abnormalities that degrade building performance, such as using more energy than normal operation, failing to maintain building temperatures according to the thermostat set points, etc. Models of building faults in OpenStudio can be used to estimate fault impacts on building performance and to develop and evaluate FDD algorithms. The aim of the project is to develop fault models of typical heating, ventilating and air conditioning (HVAC) equipment in the United States, and the fault models in this report are grouped as control faults, sensor faults, packaged and split air conditioner faults, water-cooled chiller faults, and other uncategorized faults. The control fault models simulate impacts of inappropriate thermostat control schemes such as an incorrect thermostat set point in unoccupied hours and manual changes of thermostat set point due to extreme outside temperature. Sensor fault models focus on the modeling of sensor biases including economizer relative humidity sensor bias, supply air temperature sensor bias, and water circuit temperature sensor bias. Packaged and split air conditioner fault models simulate refrigerant undercharging, condenser fouling, condenser fan motor efficiency degradation, non-condensable entrainment in refrigerant, and liquid line restriction. Other fault models that are uncategorized include duct fouling, excessive infiltration into the building, and blower and pump motor degradation.

  13. Direct measurement of the work of fracture for grain boundaries of twist misorientation about (100) in tungsten

    SciTech Connect (OSTI)

    Liu, J.M.; Shen, B.W.

    1984-06-01

    The authors report results on the direct measurement of the work of fracture in twist boundaries in electron beam zone refined bicrystals of tungsten. The work of fracture is referred to as the energy required for crack extension. This approach may be used to advantage when the effects of impurities are present, for example, in problems related to grain boundary embrittlement in steels, copper and nickel.

  14. Renewable Energy Renaissance Zones

    Office of Energy Efficiency and Renewable Energy (EERE)

    For the purposes of renaissance zone designation, “renewable energy facility” means a facility that creates energy, fuels, or chemicals directly from the wind, the sun, trees, grasses, bio-solids,...

  15. Nuclear, multichannel-sonic, ultrasonic analyses for determination of degree of fracturing and alteration in a fast formation: The deep ocean crust

    SciTech Connect (OSTI)

    Anderson, R.N.; O'Malley, H.; Newmark, R.L.

    1984-01-01

    Multichannel, Full-Waveform Sonic Logs offer quantitative information on the response of the formation to propagating acoustic energy. When coupled with ultrasonic borehole imagery, these logs show clear evidence of fractures intersecting the wellbore. P-wave, S-wave, Stoneley and late arriving normal modal CODA all show energy and frequency changes across fracture zones. One critical ingredient missing from the sonic-ultrasonic cross-correlations to date, has been the ability to estimate the quantity of alteration material infilling fractures. A new nuclear analysis technique has been developed to extract a reliable estimate of the amount of clay infilling in highly fractured basalts from the oceanic crust.

  16. Deficiencies in Vadose Zone Understanding at the INEEL

    SciTech Connect (OSTI)

    Wood, Thomas Ronald; Bates, Dona Louise; Bishop, Carolyn Wagoner; Heard, Robert Eugene; Hubbell, Joel Michael; Hull, Laurence Charles; Lehman, Richard Michael; Magnuson, Swen O; Mattson, Earl Douglas; Mccarthy, James Michael; Porro, Indrek; Ritter, Paul David; Roddy, Michael Scott; Singler, Robert Edward; Smith, Richard Paul

    2000-08-01

    Subsurface contamination in the vadose zone, that portion of the subsurface pathway between land surface and an underlying aquifer, poses environmental problems at the Idaho National Engineering and Environmental Laboratory (INEEL) in eastern Idaho and across the U.S. Department of Energy complex. Assessing potential adverse impacts from these contaminated sites requires an understanding of the mechanisms controlling contaminant transport. Currently, vadose zone experts at the INEEL cannot with confidence predict the movement of water and contaminants in the complex, heterogeneous, fractured subsurface at the INEEL, especially within the vadose zone. In the draft version (Revision 1) of the Vadose Zone Deficiencies document, deficiencies in scientific understanding of flow and transport processes in the vadose zone at the INEEL were identified and grouped into 13 categories and recommendations were provided to address each of the deficiencies. The draft document provided the basis for an INEEL Vadose Zone Workshop that was conducted October 20 and 21, 1999, in Idaho Falls, Idaho. The workshop was conducted to group and rank the previously identified deficiencies and for the subsequent development of science plans to address the deficiencies that limit reliable predictions of water and contaminant movement in the subsurface. The workshop participants, comprising INEEL and scientists and project managers and non-INEEL scientists knowledgeable about the vadose zone, developed science- and technology-based recommendations derived through a series of technical sessions at the workshop. In this document, the final version of the Vadose Zone Deficiencies document, the draft document has been incorporated, largely intact, as well as the results from the workshop. The workshop participants grouped the deficiencies in vadose zone understanding at the INEEL into seven categories. These seven categories will be the focus areas of five science plans that are being developed to address the deficiencies. This document lays the foundation for the INEEL Site-wide vadose zone roadmap.

  17. Probing the deep critical zone beneath the Luquillo Experimental Forest, Puerto Rico

    SciTech Connect (OSTI)

    Buss, Heather; Brantley, S. L.; Scatena, Fred; Bazilevskaya, Ekaterina; Blum, Alex; Schulz, M; Jimenez, M; White, Art; Rother, Gernot; Cole, David

    2013-01-01

    Recent work has suggested that weathering processes occurring in the subsurface produce the majority of silicate weathering products discharged to the world s oceans, thereby exerting a primary control on global temperature via the well-known positive feedback between silicate weathering and CO2. In addition, chemical and physical weathering processes deep within the critical zone create aquifers and control groundwater chemistry, watershed geometry and regolith formation rates. Despite this, most weathering studies are restricted to the shallow critical zone (e.g., soils, outcrops). Here we investigate the chemical weathering, fracturing and geomorphology of the deep critical zone in the Bisley watershed in the Luquillo Critical Zone Observatory, Puerto Rico, from two boreholes drilled to 37.2 and 27.0 m depth, from which continuous core samples were taken. Corestones exposed aboveground were also sampled. Weathered rinds developed on exposed corestones and along fracture surfaces on subsurface rocks slough off of exposed corestones once rinds attain a thickness up to ~1 cm, preventing the corestones from rounding due to diffusion limitation. Such corestones at the land surface are assumed to be what remains after exhumation of similar, fractured bedrock pieces that were observed in the drilled cores between thick layers of regolith. Some of these subsurface corestones are massive and others are highly fractured, whereas aboveground corestones are generally massive with little to no apparent fracturing. Subsurface corestones are larger and less fractured in the borehole drilled on a road where it crosses a ridge compared to the borehole drilled where the road crosses the stream channel. Both borehole profiles indicate that the weathering zone extends to well below the stream channel in this upland catchment; hence weathering depth is not controlled by the stream level within the catchment and not all of the water in the watershed is discharged to the stream.

  18. Natural time analysis of critical phenomena: The case of pre-fracture electromagnetic emissions

    SciTech Connect (OSTI)

    Potirakis, S. M.; Karadimitrakis, A.; Eftaxias, K.

    2013-06-15

    Criticality of complex systems reveals itself in various ways. One way to monitor a system at critical state is to analyze its observable manifestations using the recently introduced method of natural time. Pre-fracture electromagnetic (EM) emissions, in agreement to laboratory experiments, have been consistently detected in the MHz band prior to significant earthquakes. It has been proposed that these emissions stem from the fracture of the heterogeneous materials surrounding the strong entities (asperities) distributed along the fault, preventing the relative slipping. It has also been proposed that the fracture of heterogeneous material could be described in analogy to the critical phase transitions in statistical physics. In this work, the natural time analysis is for the first time applied to the pre-fracture MHz EM signals revealing their critical nature. Seismicity and pre-fracture EM emissions should be two sides of the same coin concerning the earthquake generation process. Therefore, we also examine the corresponding foreshock seismic activity, as another manifestation of the same complex system at critical state. We conclude that the foreshock seismicity data present criticality features as well.

  19. Fault Locating, Prediction and Protection (FLPPS)

    SciTech Connect (OSTI)

    Yinger, Robert, J.; Venkata, S., S.; Centeno, Virgilio

    2010-09-30

    One of the main objectives of this DOE-sponsored project was to reduce customer outage time. Fault location, prediction, and protection are the most important aspects of fault management for the reduction of outage time. In the past most of the research and development on power system faults in these areas has focused on transmission systems, and it is not until recently with deregulation and competition that research on power system faults has begun to focus on the unique aspects of distribution systems. This project was planned with three Phases, approximately one year per phase. The first phase of the project involved an assessment of the state-of-the-art in fault location, prediction, and detection as well as the design, lab testing, and field installation of the advanced protection system on the SCE Circuit of the Future located north of San Bernardino, CA. The new feeder automation scheme, with vacuum fault interrupters, will limit the number of customers affected by the fault. Depending on the fault location, the substation breaker might not even trip. Through the use of fast communications (fiber) the fault locations can be determined and the proper fault interrupting switches opened automatically. With knowledge of circuit loadings at the time of the fault, ties to other circuits can be closed automatically to restore all customers except the faulted section. This new automation scheme limits outage time and increases reliability for customers. The second phase of the project involved the selection, modeling, testing and installation of a fault current limiter on the Circuit of the Future. While this project did not pay for the installation and testing of the fault current limiter, it did perform the evaluation of the fault current limiter and its impacts on the protection system of the Circuit of the Future. After investigation of several fault current limiters, the Zenergy superconducting, saturable core fault current limiter was selected for installation. Because of some testing problems with the Zenergy fault current limiter, installation was delayed until early 2009 with it being put into operation on March 6, 2009. A malfunction of the FCL controller caused the DC power supply to the superconducting magnet to be turned off. This inserted the FCL impedance into the circuit while it was in normal operation causing a voltage resonance condition. While these voltages never reached a point where damage would occur on customer equipment, steps were taken to insure this would not happen again. The FCL was reenergized with load on December 18, 2009. A fault was experienced on the circuit with the FCL in operation on January 14, 2010. The FCL operated properly and reduced the fault current by about 8%, what was expected from tests and modeling. As of the end of the project, the FCL was still in operation on the circuit. The third phase of the project involved the exploration of several advanced protection ideas that might be at a state where they could be applied to the Circuit of the Future and elsewhere in the SCE electrical system. Based on the work done as part of the literature review and survey, as well as a number of internal meetings with engineering staff at SCE, a number of ideas were compiled. These ideas were then evaluated for applicability and ability to be applied on the Circuit of the Future in the time remaining for the project. Some of these basic ideas were implemented on the circuit including measurement of power quality before and after the FCL. It was also decided that we would take what was learned as part of the Circuit of the Future work and extend it to the next generation circuit protection for SCE. Also at this time, SCE put in a proposal to the DOE for the Irvine Smart Grid Demonstration using ARRA funding. SCE was successful in obtaining funding for this proposal, so it was felt that exploration of new protection schemes for this Irvine Smart Grid Demonstration would be a good use of the project resources. With this in mind, a protection system that uses fault interrupting switches, high speed communications, and looping two radial distribution circuits would have the potential for significant reductions in interruption time and number of interruptions for customers.

  20. A 3-Dimensional discrete fracture network generator to examine fracture-matrix interaction using TOUGH2

    SciTech Connect (OSTI)

    Ito, Kazumasa; Yongkoo, Seol

    2003-04-09

    Water fluxes in unsaturated, fractured rock involve the physical processes occurring at fracture-matrix interfaces within fracture networks. Modeling these water fluxes using a discrete fracture network model is a complicated effort. Existing preprocessors for TOUGH2 are not suitable to generate grids for fracture networks with various orientations and inclinations. There are several 3-D discrete-fracture-network simulators for flow and transport, but most of them do not capture fracture-matrix interaction. We have developed a new 3-D discrete-fracture-network mesh generator, FRACMESH, to provide TOUGH2 with information about the fracture network configuration and fracture-matrix interactions. FRACMESH transforms a discrete fracture network into a 3 dimensional uniform mesh, in which fractures are considered as elements with unique rock material properties and connected to surrounding matrix elements. Using FRACMESH, individual fractures may have uniform or random aperture distributions to consider heterogeneity. Fracture element volumes and interfacial areas are calculated from fracture geometry within individual elements. By using FRACMESH and TOUGH2, fractures with various inclinations and orientations, and fracture-matrix interaction, can be incorporated. In this paper, results of flow and transport simulations in a fractured rock block utilizing FRACMESH are presented.

  1. Detecting Fractures Using Technology at High Temperatures and...

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    Fractures Using Technology at High Temperatures and Depths - Geothermal Ultrasonic Fracture Imager (GUFI); 2010 Geothermal Technology Program Peer Review Report Detecting Fractures ...

  2. Establishment of Stress-Permeabilty relationship of fractured...

    Office of Scientific and Technical Information (OSTI)

    ... hydraulic conductivity for intact and fractured ... D, Hayashi K, Effect of thermal deformation on fracture ... constant (K) Fracture density* (m -2 ) Mean trace ...

  3. Microsoft Word - EPA 6 Analysis of Fracture Propagation_final...

    Office of Scientific and Technical Information (OSTI)

    Fracture Propagation, Fluid Flow, and Geomechanics of Water-Based Hydraulic Fracturing in ... induced by hydraulic fracturing with water injection, using numerical simulation. ...

  4. Hydrogeology of the unsaturated zone, Yucca Mountain, Nevada

    SciTech Connect (OSTI)

    Montazer, P.; Wilson, W.E.

    1985-12-31

    The unsaturated volcanic tuff beneath Yucca Mountain, Nevada, is being evaluated by the US Department of Energy as a host rock for a potential mined geologic repository for high-level radioactive waste. Assessment of site suitability needs an efficient and focused investigative program. A conceptual hydrogeologic model that simulates the flow of fluids through the unsaturated zone at Yucca Mountain was developed to guide the program and to provide a basis for preliminary assessment of site suitability. The study was made as part of the Nevada Nuclear Waste Storage Investigations Project of the US Department of Energy. Thickness of the unsaturated zone is about 1640 to 2460 feet (500 to 750 meters). Based on physical properties, the rocks in the unsaturated zone are grouped for the purpose of this paper into five informal hydrogeologic units. From top to bottom these units are: Tiva Canyon welded unit, Paintbrush nonwelded unit. Topopah Spring welded unit, Calico Hills nonwelded unit, and Crater Flat unit. Welded units have a mean fracture density of 8 to 40 fractures per unit cubic meter, mean matrix porosities of 12 to 23%, matrix hydraulic conductivities with geometric means ranging from 6.5 x 10{sup -6} to 9.8 x 10{sup -6} foot per day (2 x 10{sup -6} to 3 x 10{sup -6} meter per day), and bulk hydraulic conductivities of 0.33 to 33 feet per day (0.1 to 10 meters per day). The nonwelded units have a mean fracture density of 1 to 3 fractures per unit cubic meter, mean matrix porosities of 31 to 46%, and saturated hydraulic conductivities with geometric means ranging from 2.6 x 10{sup -5} to 2.9 x 10{sup -2} foot per day (8 x 10{sup -6} to 9 x 10{sup -3} meter per day). 15 refs., 4 figs., 1 tab.

  5. Fault Detection and Load Distribution for the Wind Farm Challenge

    SciTech Connect (OSTI)

    Borchehrsen, Anders B.; Larsen, Jesper A.; Stoustrup, Jakob

    2014-08-24

    In this paper a fault detection system and a fault tolerant controller for a wind farm model. The wind farm model used is the one proposed as a public challenge. In the model three types of faults are introduced to a wind farm consisting of nine turbines. A fault detection system designed, by taking advantage of the fact that within a wind farm several wind turbines will be operating under all most identical conditions. The turbines are then grouped, and then turbines within each group are used to generate residuals for turbines in the group. The generated residuals are then evaluated using dynamical cumulative sum. The designed fault detection system is cable of detecting all three fault types occurring in the model. But there is room for improving the fault detection in some areas. To take advantage of the fault detection system a fault tolerant controller for the wind farm has been designed. The fault tolerant controller is a dispatch controller which is estimating the possible power at each individual turbine and then setting the reference accordingly. The fault tolerant controller has been compared to a reference controller. And the comparison shows that the fault tolerant controller performance better in all measures. The fault detection and a fault tolerant controller has been designed, and based on the simulated results the overall performance of the wind farm is improved on all measures. Thereby this is a step towards improving the overall performance of current and future wind farms.

  6. Near-field/altered-zone models report

    SciTech Connect (OSTI)

    Hardin, E. L., LLNL

    1998-03-01

    The U.S. Department of Energy is studying Yucca Mountain as the possible site for the first underground repository for permanent disposal of spent fuel from commercial nuclear reactors as well as for other types high-level nuclear waste. Emplacement of high-level radioactive waste, especially commercial spent nuclear fuel (CSNF), in Yucca Mountain will release a large amount of heat into the rock above and below the repository. The heating rate will decrease with time, creating a thermal pulse. Over a period of several thousand years, the rock temperature will rise initially, then drop when the production of decay heat falls below the rate at which heat escapes from the hot zone. Besides raising the rock temperature, much of this heat will vaporize water, which will then condense in cooler regions. The condensate is likely to form a gravity-driven heat pipe above the repository, creating the possibility that water may drain back onto the waste packages (WPs) or that it may ''shed'' through the pillars between emplacement drifts. The long-term importance of these effects has been investigated through the development, testing, and application of thermohydrologic (TH) models. Other effects, such coupled chemical and mechanical processes, may also influence the movement of water above, within, and below the emplacement drifts. A recent report on thermally driven coupled processes (Hardin and Chesnut, 1997) provides a qualitative assessment of the probable significance of these processes for the Yucca Mountain Site Characterization Project (YMSCP) and is the phenomenological framework for the present report. This report describes the conceptual and numerical models that have been developed to predict the thermal, mechanical, hydrologic, and chemical responses to the cumulative heat production of the potential host rock at Yucca Mountain. As proposed, the repository horizon will be situated within the Topopah Spring tuff, in the adjacent middle nonlithophysal and lower lithophysal units. These units are made up of moderately to densely welded, devitrified, fractured tuff. The rock's chemical composition is comparable to that of typical granite, but has textural features and mineralogical characteristics of large-scale, silicic volcanism. Because the repository horizon will be approximately 300 m below the ground surface and 200 m above the water table, the repository will be partially saturated. The welded tuff matrix in the host units is highly impermeable, but water and gas flow readily through fractures. The degree of fracturing in these units is highly variable, and the hydrologic significance of fracturing is an important aspect of site investigation. This report describes the characterization and modeling of a region around the potential repository--the altered zone--a region in which the temperature will be increased significantly by waste-generated heat. Numerical simulation has shown that, depending on the boundary conditions, rock properties, and repository design features incorporated in the models, the altered zone (AZ) may extend from the water table to the ground surface. This report also describes models of the near field, the region comprising the repository emplacement drifts and the surrounding rock, which are critical to the performance of engineered components. Investigations of near-field and altered-zone (NF/AZ) processes support the design of underground repository facilities and engineered barriers and also provide constraint data for probabilistic calculations of waste-isolation performance (i.e., performance assessment). The approach to investigation, which is an iterative process involving hypothesis testing and experimentation, has relied on conceptualizing engineered barriers and on performance analysis. This report is a collection, emphasizing conceptual and numerical models, of the recent results contributed from studies of NF/AZ processes and of quantitative measures of NF/AZ performance. The selection and presentation of contributions are intended to show the iterative development of understand

  7. Naturally fractured tight gas: Gas reservoir detection optimization. Quarterly report, January 1--March 31, 1997

    SciTech Connect (OSTI)

    1997-12-31

    Economically viable natural gas production from the low permeability Mesaverde Formation in the Piceance Basin, Colorado requires the presence of an intense set of open natural fractures. Establishing the regional presence and specific location of such natural fractures is the highest priority exploration goal in the Piceance and other western US tight, gas-centered basins. Recently, Advanced Resources International, Inc. (ARI) completed a field program at Rulison Field, Piceance Basin, to test and demonstrate the use of advanced seismic methods to locate and characterize natural fractures. This project began with a comprehensive review of the tectonic history, state of stress and fracture genesis of the basin. A high resolution aeromagnetic survey, interpreted satellite and SLAR imagery, and 400 line miles of 2-D seismic provided the foundation for the structural interpretation. The central feature of the program was the 4.5 square mile multi-azimuth 3-D seismic P-wave survey to locate natural fracture anomalies. The interpreted seismic attributes are being tested against a control data set of 27 wells. Additional wells are currently being drilled at Rulison, on close 40 acre spacings, to establish the productivity from the seismically observed fracture anomalies. A similar regional prospecting and seismic program is being considered for another part of the basin. The preliminary results indicate that detailed mapping of fault geometries and use of azimuthally defined seismic attributes exhibit close correlation with high productivity gas wells. The performance of the ten new wells, being drilled in the seismic grid in late 1996 and early 1997, will help demonstrate the reliability of this natural fracture detection and mapping technology.

  8. Method for directional hydraulic fracturing

    DOE Patents [OSTI]

    Swanson, David E.; Daly, Daniel W.

    1994-01-01

    A method for directional hydraulic fracturing using borehole seals to confine pressurized fluid in planar permeable regions, comprising: placing a sealant in the hole of a structure selected from geologic or cemented formations to fill the space between a permeable planar component and the geologic or cemented formation in the vicinity of the permeable planar component; making a hydraulic connection between the permeable planar component and a pump; permitting the sealant to cure and thereby provide both mechanical and hydraulic confinement to the permeable planar component; and pumping a fluid from the pump into the permeable planar component to internally pressurize the permeable planar component to initiate a fracture in the formation, the fracture being disposed in the same orientation as the permeable planar component.

  9. VCSEL fault location apparatus and method

    DOE Patents [OSTI]

    Keeler, Gordon A.; Serkland, Darwin K.

    2007-05-15

    An apparatus for locating a fault within an optical fiber is disclosed. The apparatus, which can be formed as a part of a fiber-optic transmitter or as a stand-alone instrument, utilizes a vertical-cavity surface-emitting laser (VCSEL) to generate a test pulse of light which is coupled into an optical fiber under test. The VCSEL is subsequently reconfigured by changing a bias voltage thereto and is used as a resonant-cavity photodetector (RCPD) to detect a portion of the test light pulse which is reflected or scattered from any fault within the optical fiber. A time interval .DELTA.t between an instant in time when the test light pulse is generated and the time the reflected or scattered portion is detected can then be used to determine the location of the fault within the optical fiber.

  10. P-waves imaging of the FRI and BK zones at the Grimsel Rock Laboratory

    SciTech Connect (OSTI)

    Majer, E.L.; Peterson, J.E. Jr. ); Blueming, P.; Sattel, G. )

    1990-08-01

    This report is one of a series documenting the results of the Nagra-DOE Cooperative (NDC-I) research program in which the cooperating scientists explore the geological, geophysical, hydrological, geochemical, and structural effects anticipated from the use of a rock mass as a geological repository for nuclear waste. Tomographic imaging studies using a high frequency (10 Khz.) piezoelectric source and a three component receiver were carried out in two different regions of the underground Nagra Grimsel test facility in Switzerland. Both sites were in fractured granite, one being in a strongly foliated granite (FRI site), and the other being in a relatively homogeneous granite (BK zone). The object of the work was to determine if the seismic techniques could be useful in imaging the fracture zones and provide information on the hydrologic conditions. Both amplitude and velocity tomograms were obtained from the Data. The results indicate that the fracture zones strongly influenced the seismic wave propagation, thus imaging the fracture zones that were hydrologically important. 11 refs., 24 figs.

  11. Hydrogen fracture toughness tester completion

    SciTech Connect (OSTI)

    Morgan, Michael J.

    2015-09-30

    The Hydrogen Fracture Toughness Tester (HFTT) is a mechanical testing machine designed for conducting fracture mechanics tests on materials in high-pressure hydrogen gas. The tester is needed for evaluating the effects of hydrogen on the cracking properties of tritium reservoir materials. It consists of an Instron Model 8862 Electromechanical Test Frame; an Autoclave Engineering Pressure Vessel, an Electric Potential Drop Crack Length Measurement System, associated computer control and data acquisition systems, and a high-pressure hydrogen gas manifold and handling system.

  12. Phase I (Year 1) Summary of Research--Establishing the Relationship between Fracture-Related Dolomite and Primary Rock Fabric on the Distribution of Reservoirs in the Michigan Basin

    SciTech Connect (OSTI)

    G. Michael Grammer

    2005-11-09

    This topical report covers the first 12 months of the subject 3-year grant, evaluating the relationship between fracture-related dolomite and dolomite constrained by primary rock fabric in the 3 most prolific reservoir intervals in the Michigan Basin (Ordovician Trenton-Black River Formations; Silurian Niagara Group; and the Devonian Dundee Formation). Phase I tasks, including Developing a Reservoir Catalog for selected dolomite reservoirs in the Michigan Basin, Characterization of Dolomite Reservoirs in Representative Fields and Technology Transfer have all been initiated and progress is consistent with our original scheduling. The development of a reservoir catalog for the 3 subject formations in the Michigan Basin has been a primary focus of our efforts during Phase I. As part of this effort, we currently have scanned some 13,000 wireline logs, and compiled in excess of 940 key references and 275 reprints that cover reservoir aspects of the 3 intervals in the Michigan Basin. A summary evaluation of the data in these publications is currently ongoing, with the Silurian Niagara Group being handled as a first priority. In addition, full production and reservoir parameter data bases obtained from available data sources have been developed for the 3 intervals in Excel and Microsoft Access data bases. We currently have an excess of 25 million cells of data for wells in the Basin. All Task 2 objectives are on time and on target for Phase I per our original proposal. Our mapping efforts to date, which have focused in large part on the Devonian Dundee Formation, have important implications for both new exploration plays and improved enhanced recovery methods in the Dundee ''play'' in Michigan--i.e. the interpreted fracture-related dolomitization control on the distribution of hydrocarbon reservoirs. In an exploration context, high-resolution structure mapping using quality-controlled well data should provide leads to convergence zones of fault/fracture trends that are not necessarily related to structural elevation. Further work in Phase II will be focused on delineating the relative contribution to fracture-only dolomitization to that which occurs in conjunction with primary facies and/or sequence stratigraphic framework.

  13. Fault-tolerant three-level inverter

    DOE Patents [OSTI]

    Edwards, John; Xu, Longya; Bhargava, Brij B.

    2006-12-05

    A method for driving a neutral point clamped three-level inverter is provided. In one exemplary embodiment, DC current is received at a neutral point-clamped three-level inverter. The inverter has a plurality of nodes including first, second and third output nodes. The inverter also has a plurality of switches. Faults are checked for in the inverter and predetermined switches are automatically activated responsive to a detected fault such that three-phase electrical power is provided at the output nodes.

  14. ADVANCED CHARACTERIZATION OF FRACTURED RESERVOIRS IN CARBONATE ROCKS: THE MICHIGAN BASIN

    SciTech Connect (OSTI)

    James R. Wood; William B. Harrison

    2002-12-01

    The purpose of the study was to collect and analyze existing data on the Michigan Basin for fracture patterns on scales ranging form thin section to basin. The data acquisition phase has been successfully concluded with the compilation of several large digital databases containing nearly all the existing information on formation tops, lithology and hydrocarbon production over the entire Michigan Basin. These databases represent the cumulative result of over 80 years of drilling and exploration. Plotting and examination of these data show that contrary to most depictions, the Michigan Basin is in fact extensively faulted and fractured, particularly in the central portion of the basin. This is in contrast to most of the existing work on the Michigan Basin, which tends to show relatively simple structure with few or minor faults. It also appears that these fractures and faults control the Paleozoic sediment deposition, the subsequent hydrocarbon traps and very likely the regional dolomitization patterns. Recent work has revealed that a detailed fracture pattern exists in the interior of the Central Michigan Basin, which is related to the mid-continent gravity high. The inference is that early Precambrian, ({approx}1 Ga) rifting events presumed by many to account for the gravity anomaly subsequently controlled Paleozoic sedimentation and later hydrocarbon accumulation. There is a systematic relationship between the faults and a number of gas and oil reservoirs: major hydrocarbon accumulations consistently occur in small anticlines on the upthrown side of the faults. The main tools used in this study to map the fault/fracture patterns are detailed, close-interval (CI = 10 feet) contouring of the formation top picks accompanied by a new way of visualizing the data using a special color spectrum to bring out the third dimension. In addition, recent improvements in visualization and contouring software were instrumental in the study. Dolomitization is common in the Michigan Basin, and it is crucial in developing reservoir quality rocks in some fields. Data on the occurrence of dolomite was extracted from driller's reports for all reported occurrences in Michigan, nearly 50 fields and over 500 wells. A digital database was developed containing the geographic location of all these wells (latitude-longitude) as well as the elevation of the first encounter of dolomite in the field/reservoir. Analysis shows that these dolomite occurrences are largely confined to the center of the basin, but with some exceptions, such as N. Adams Field. Further, some of the dolomite occurrences show a definite relationship to the fracture pattern described above, suggesting a genetic relationship that needs further work. Other accomplishments of this past reporting period include obtaining a complete land grid for the State of Michigan and further processing of the high and medium resolution DEM files. We also have measured new fluid inclusion data on dolomites from several fields that suggest that the dolomitization occurred at temperatures between 100 and 150 C. Finally, we have extracted the lithologic data for about 5000 wells and are in the process of integrating this data into the overall model for the Michigan Basin.

  15. Hydraulic Fracturing | OpenEI Community

    Open Energy Info (EERE)

    Hydraulic Fracturing Home Wayne31jan's picture Submitted by Wayne31jan(150) Contributor 30 June, 2015 - 03:49 Shale Gas Application in Hydraulic Fracturing Market is likely to grow...

  16. Hydraulic Fracturing Market | OpenEI Community

    Open Energy Info (EERE)

    Hydraulic Fracturing Market Home Wayne31jan's picture Submitted by Wayne31jan(150) Contributor 30 June, 2015 - 03:49 Shale Gas Application in Hydraulic Fracturing Market is likely...

  17. Arc-Fault Detector Algorithm Evaluation Method Utilizing Prerecorded...

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Index Terms - photovoltaic systems, arc-fault detection, series arc-faults, monitoring, power system safety I. INTRODUCTION In order to improve fire safety in PV systems, the 2011...

  18. Intergranular fracture in UO2: derivation of traction-separation law from atomistic simulations

    SciTech Connect (OSTI)

    Yongfeng Zhang; Paul C Millett; Michael R Tonks; Xian-Ming Bai; S Bulent Biner

    2013-10-01

    In this study, the intergranular fracture behavior of UO2 was studied by molecular dynamics simulations using the Basak potential. In addition, the constitutive traction-separation law was derived from atomistic data using the cohesive-zone model. In the simulations a bicrystal model with the (100) symmetric tilt E5 grain boundaries was utilized. Uniaxial tension along the grain boundary normal was applied to simulate Mode-I fracture. The fracture was observed to propagate along the grain boundary by micro-pore nucleation and coalescence, giving an overall intergranular fracture behavior. Phase transformations from the Fluorite to the Rutile and Scrutinyite phases were identified at the propagating crack tips. These new phases are metastable and they transformed back to the Fluorite phase at the wake of crack tips as the local stress concentration was relieved by complete cracking. Such transient behavior observed at atomistic scale was found to substantially increase the energy release rate for fracture. Insertion of Xe gas into the initial notch showed minor effect on the overall fracture behavior.

  19. Detachment Faulting & Geothermal Resources- Pearl Hot Spring, NV

    Broader source: Energy.gov [DOE]

    Detachment Faulting & Geothermal Resources - Pearl Hot Spring, NV presentation at the April 2013 peer review meeting held in Denver, Colorado.

  20. Deep drilling phase of the Pen Brand Fault Program

    SciTech Connect (OSTI)

    Stieve, A.

    1991-05-15

    This deep drilling activity is one element of the Pen Branch Fault Program at Savannah River Site (SRS). The effort will consist of three tasks: the extension of wells PBF-7 and PBF-8 into crystalline basement, geologic and drilling oversight during drilling operations, and the lithologic description and analysis of the recovered core. The drilling program addresses the association of the Pen Branch fault with order fault systems such as the fault that formed the Bunbarton basin in the Triassic.

  1. Adjustable direct current and pulsed circuit fault current limiter

    DOE Patents [OSTI]

    Boenig, Heinrich J.; Schillig, Josef B.

    2003-09-23

    A fault current limiting system for direct current circuits and for pulsed power circuit. In the circuits, a current source biases a diode that is in series with the circuits' transmission line. If fault current in a circuit exceeds current from the current source biasing the diode open, the diode will cease conducting and route the fault current through the current source and an inductor. This limits the rate of rise and the peak value of the fault current.

  2. Understanding Fault Characteristics of Inverter-Based Distributed Energy Resources

    SciTech Connect (OSTI)

    Keller, J.; Kroposki, B.

    2010-01-01

    This report discusses issues and provides solutions for dealing with fault current contributions from inverter-based distributed energy resources.

  3. NaturAnalogs for the Unsaturated Zone

    SciTech Connect (OSTI)

    A. Simmons; A. Unger; M. Murrell

    2000-03-08

    The purpose of this Analysis/Model Report (AMR) is to document natural and anthropogenic (human-induced) analog sites and processes that are applicable to flow and transport processes expected to occur at the potential Yucca Mountain repository in order to build increased confidence in modeling processes of Unsaturated Zone (UZ) flow and transport. This AMR was prepared in accordance with ''AMR Development Plan for U0135, Natural Analogs for the UZ'' (CRWMS 1999a). Knowledge from analog sites and processes is used as corroborating information to test and build confidence in flow and transport models of Yucca Mountain, Nevada. This AMR supports the Unsaturated Zone (UZ) Flow and Transport Process Model Report (PMR) and the Yucca Mountain Site Description. The objectives of this AMR are to test and build confidence in the representation of UZ processes in numerical models utilized in the UZ Flow and Transport Model. This is accomplished by: (1) applying data from Boxy Canyon, Idaho in simulations of UZ flow using the same methodologies incorporated in the Yucca Mountain UZ Flow and Transport Model to assess the fracture-matrix interaction conceptual model; (2) Providing a preliminary basis for analysis of radionuclide transport at Pena Blanca, Mexico as an analog of radionuclide transport at Yucca Mountain; and (3) Synthesizing existing information from natural analog studies to provide corroborating evidence for representation of ambient and thermally coupled UZ flow and transport processes in the UZ Model.

  4. Multi-directional fault detection system

    DOE Patents [OSTI]

    Archer, Charles Jens; Pinnow, Kurt Walter; Ratterman, Joseph D.; Smith, Brian Edward

    2009-03-17

    An apparatus, program product and method checks for nodal faults in a group of nodes comprising a center node and all adjacent nodes. The center node concurrently communicates with the immediately adjacent nodes in three dimensions. The communications are analyzed to determine a presence of a faulty node or connection.

  5. Multi-directional fault detection system

    DOE Patents [OSTI]

    Archer, Charles Jens; Pinnow, Kurt Walter; Ratterman, Joseph D.; Smith, Brian Edward

    2010-11-23

    An apparatus, program product and method checks for nodal faults in a group of nodes comprising a center node and all adjacent nodes. The center node concurrently communicates with the immediately adjacent nodes in three dimensions. The communications are analyzed to determine a presence of a faulty node or connection.

  6. All row, planar fault detection system

    DOE Patents [OSTI]

    Archer, Charles Jens; Pinnow, Kurt Walter; Ratterman, Joseph D; Smith, Brian Edward

    2013-07-23

    An apparatus, program product and method for detecting nodal faults may simultaneously cause designated nodes of a cell to communicate with all nodes adjacent to each of the designated nodes. Furthermore, all nodes along the axes of the designated nodes are made to communicate with their adjacent nodes, and the communications are analyzed to determine if a node or connection is faulty.

  7. Multi-directional fault detection system

    DOE Patents [OSTI]

    Archer, Charles Jens; Pinnow, Kurt Walter; Ratterman, Joseph D.; Smith, Brian Edward

    2010-06-29

    An apparatus, program product and method checks for nodal faults in a group of nodes comprising a center node and all adjacent nodes. The center node concurrently communicates with the immediately adjacent nodes in three dimensions. The communications are analyzed to determine a presence of a faulty node or connection.

  8. Seismic Reflection Project Near the Southern Terminations of the Lost River and Lemhi Faults, Eastern Snake River Plain, Idaho

    SciTech Connect (OSTI)

    S. M. Jackson; G. S. Carpenter; R. P. Smith; J. L. Casper

    2006-10-01

    Thirteen seismic reflection lines were processed and interpreted to determine the southern terminations of the Lost River and Lemhi faults along the northwest boundary of the eastern Snake River Plain (ESRP). The southernmost terminations of the Arco and Howe segments were determined to support characterization of the Lost River and Lemhi fault sources, respectively, for the INL probabilistic seismic hazard analysis. Keywords:Keywords are required forExternal Release Review*Keywords  Keywords *Contacts (Type and Name are required for each row) Type ofContactContact Name  POC Editor RecordFour commercial seismic reflection lines (Arco lines 81-1 and 81-2; Howe lines 81-3 and 82-2) were obtained from the Montana Power Company. The seismic data were collected in the early 1980’s using a Vibroseis source with station and shot point locations that resulted in 12-fold data. Arco lines 81?1 and 81?2 and Howe lines 81?3 and 82?2 are located within the basins adjacent to the Arco and Howe segments, respectively. Seven seismic lines (Arco lines A1, A2, A3, and A4 and Howe lines H1, H2, and H3) were acquired by EG&G Idaho, Inc. Geosciences for this study using multiple impacts with an accelerated weight drop source. Station and shot point locations yielded 12-fold data. The seismic reflection lines are oriented perpendicular to and at locations along the projected extensions of the Arco and Howe fault segments within the ESRP. Two seismic lines (Arco line S2 and Howe line S4) were obtained from Sierra Geophysics. In 1984, they acquired seismic reflection data using an accelerated weight drop source with station and shot point locations that yielded 6-fold data. The two seismic reflection lines are oriented perpendicular to and at locations along the projected extensions of the Arco and Howe fault segments within the ESRP. In 1992 for this study, Geotrace Technologies Inc. processed all of the seismic reflection data using industry standard processing techniques. The southern termination of the Howe segment of the Lemhi fault was placed between Howe lines H1 and H2, 2.2 km south of the fault’s southernmost surface expression. In the adjacent basin, south-dipping normal faults at the northern end of Howe line 81-3 and two southwest-dipping normal faults at the northeastern end of Howe line 82-2 that can be correlated with Howe segment. South of the surface expression, two southwest-dipping normal faults on Howe line H1 can be correlated with the Howe segment. Further into the ESRP, Howe lines H2, H3, and S4 show continuous flat lying reflectors and indicate no fault offset. The southern termination of the Arco segment of the Lost River fault was placed between Arco lines S2 and A3, a distance of 4.6 km south of the fault’s southernmost surface expression. Within the basin, west-dipping normal faults interpreted on Arco lines 81-1 and 81-2 can be correlated with the Arco segment. Further south within the Arco volcanic rift zone (VRZ), three seismic lines (Arco lines A2, S2, and A3) permit two interpretations. The west- and south-dipping normal faults on Arco lines A2 and S2 could be associated with slip along the Arco segment. These normal faults have an opposite dip to an east-dipping fault on Arco line A3. The observed small-offsets (< 85 m) along the oppositely dipping normal faults can be interpreted as a graben structure that resulted from dike intrusion within the Arco VRZ. Arco line A4 further south within the Arco VRZ shows flat lyin

  9. 3-D RESERVOIR AND STOCHASTIC FRACTURE NETWORK MODELING FOR ENHANCED OIL RECOVERY, CIRCLE RIDGE PHOSPHORIA/TENSLEEP RESERVOIR, WIND RIVER RESERVATION, ARAPAHO AND SHOSHONE TRIBES, WYOMING

    SciTech Connect (OSTI)

    Paul La Pointe; Jan Hermanson; Robert Parney; Thorsten Eiben; Mike Dunleavy; Ken Steele; John Whitney; Darrell Eubanks; Roger Straub

    2002-11-18

    This report describes the results made in fulfillment of contract DE-FG26-00BC15190, ''3-D Reservoir and Stochastic Fracture Network Modeling for Enhanced Oil Recovery, Circle Ridge Phosphoria/Tensleep Reservoir, Wind River Reservation, Arapaho and Shoshone Tribes, Wyoming''. The goal of this project is to improve the recovery of oil from the Tensleep and Phosphoria Formations in Circle Ridge Oilfield, located on the Wind River Reservation in Wyoming, through an innovative integration of matrix characterization, structural reconstruction, and the characterization of the fracturing in the reservoir through the use of discrete fracture network models. Fields in which natural fractures dominate reservoir permeability, such as the Circle Ridge Field, often experience sub-optimal recovery when recovery processes are designed and implemented that do not take advantage of the fracture systems. For example, a conventional waterflood in a main structural block of the Field was implemented and later suspended due to unattractive results. It is estimated that somewhere less than 20% of the OOIP in the Circle Ridge Field have been recovered after more than 50 years' production. Marathon Oil Company identified the Circle Ridge Field as an attractive candidate for several advanced IOR processes that explicitly take advantage of the natural fracture system. These processes require knowledge of the distribution of matrix porosity, permeability and oil saturations; and understanding of where fracturing is likely to be well-developed or poorly developed; how the fracturing may compartmentalize the reservoir; and how smaller, relatively untested subthrust fault blocks may be connected to the main overthrust block. For this reason, the project focused on improving knowledge of the matrix properties, the fault block architecture and to develop a model that could be used to predict fracture intensity, orientation and fluid flow/connectivity properties. Knowledge of matrix properties was greatly extended by calibrating wireline logs from 113 wells with incomplete or older-vintage logging suites to wells with a full suite of modern logs. The model for the fault block architecture was derived by 3D palinspastic reconstruction. This involved field work to construct three new cross-sections at key areas in the Field; creation of horizon and fault surface maps from well penetrations and tops; and numerical modeling to derive the geometry, chronology, fault movement and folding history of the Field through a 3D restoration of the reservoir units to their original undeformed state. The methodology for predicting fracture intensity and orientation variations throughout the Field was accomplished by gathering outcrop and subsurface image log fracture data, and comparing it to the strain field produced by the various folding and faulting events determined through the 3D palinspastic reconstruction. It was found that the strains produced during the initial folding of the Tensleep and Phosphoria Formations corresponded well without both the orientations and relative fracture intensity measured in outcrop and in the subsurface. The results have led to a 15% to 20% increase in estimated matrix pore volume, and to the plan to drill two horizontal drain holes located and oriented based on the modeling results. Marathon Oil is also evaluating alternative tertiary recovery processes based on the quantitative 3D integrated reservoir model.

  10. Vadose zone water fluxmeter

    DOE Patents [OSTI]

    Faybishenko, Boris A.

    2005-10-25

    A Vadose Zone Water Fluxmeter (WFM) or Direct Measurement WFM provides direct measurement of unsaturated water flow in the vadose zone. The fluxmeter is a cylindrical device that fits in a borehole or can be installed near the surface, or in pits, or in pile structures. The fluxmeter is primarily a combination of tensiometers and a porous element or plate in a water cell that is used for water injection or extraction under field conditions. The same water pressure measured outside and inside of the soil sheltered by the lower cylinder of the fluxmeter indicates that the water flux through the lower cylinder is similar to the water flux in the surrounding soil. The fluxmeter provides direct measurement of the water flow rate in the unsaturated soils and then determines the water flux, i.e. the water flow rate per unit area.

  11. Natural and Induced Fracture Diagnostics from 4-D VSP Low Permeability Gas Reservoirs

    SciTech Connect (OSTI)

    Mark E. Willis; Daniel R. Burns; M. Nafi Toksoz

    2008-09-30

    Tight gas sand reservoirs generally contain thick gas-charged intervals that often have low porosity and very low permeability. Natural and induced fractures provide the only means of production. The objective of this work is to locate and characterize natural and induced fractures from analysis of scattered waves recorded on 4-D (time lapse) VSP data in order to optimize well placement and well spacing in these gas reservoirs. Using model data simulating the scattering of seismic energy from hydraulic fractures, we first show that it is possible to characterize the quality of fracturing based upon the amount of scattering. In addition, the picked arrival times of recorded microseismic events provide the velocity moveout for isolating the scattered energy on the 4-D VSP data. This concept is applied to a field dataset from the Jonah Field in Wyoming to characterize the quality of the induced hydraulic fractures. The time lapse (4D) VSP data from this field are imaged using a migration algorithm that utilizes shot travel time tables derived from the first breaks of the 3D VSPs and receiver travel time tables based on the microseismic arrival times and a regional velocity model. Four azimuthally varying shot tables are derived from picks of the first breaks of over 200 VSP records. We create images of the fracture planes through two of the hydraulically fractured wells in the field. The scattered energy shows correlation with the locations of the microseismic events. In addition, the azimuthal scattering is different from the azimuthal reflectivity of the reservoir, giving us more confidence that we have separated the scattered signal from simple formation reflectivity. Variation of the scattered energy along the image planes suggests variability in the quality of the fractures in three distinct zones.

  12. RESEARCH PROGRAM ON FRACTURED PETROLEUM RESERVOIRS

    SciTech Connect (OSTI)

    Abbas Firoozabadi

    2002-04-12

    Numerical simulation of water injection in discrete fractured media with capillary pressure is a challenge. Dual-porosity models in view of their strength and simplicity can be mainly used for sugar-cube representation of fractured media. In such a representation, the transfer function between the fracture and the matrix block can be readily calculated for water-wet media. For a mixed-wet system, the evaluation of the transfer function becomes complicated due to the effect of gravity. In this work, they use a discrete-fracture model in which the fractures are discretized as one dimensional entities to account for fracture thickness by an integral form of the flow equations. This simple step greatly improves the numerical solution. Then the discrete-fracture model is implemented using a Galerkin finite element method. The robustness and the accuracy of the approach are shown through several examples. First they consider a single fracture in a rock matrix and compare the results of the discrete-fracture model with a single-porosity model. Then, they use the discrete-fracture model in more complex configurations. Numerical simulations are carried out in water-wet media as well as in mixed-wet media to study the effect of matrix and fracture capillary pressures.

  13. Fracture-permeability behavior of shale

    SciTech Connect (OSTI)

    Carey, J. William; Lei, Zhou; Rougier, Esteban; Mori, Hiroko; Viswanathan, Hari

    2015-05-08

    The fracture-permeability behavior of Utica shale, an important play for shale gas and oil, was investigated using a triaxial coreflood device and X-ray tomography in combination with finite-discrete element modeling (FDEM). Fractures generated in both compression and in a direct-shear configuration allowed permeability to be measured across the faces of cylindrical core. Shale with bedding planes perpendicular to direct-shear loading developed complex fracture networks and peak permeability of 30 mD that fell to 5 mD under hydrostatic conditions. Shale with bedding planes parallel to shear loading developed simple fractures with peak permeability as high as 900 mD. In addition to the large anisotropy in fracture permeability, the amount of deformation required to initiate fractures was greater for perpendicular layering (about 1% versus 0.4%), and in both cases activation of existing fractures are more likely sources of permeability in shale gas plays or damaged caprock in CO₂ sequestration because of the significant deformation required to form new fracture networks. FDEM numerical simulations were able to replicate the main features of the fracturing processes while showing the importance of fluid penetration into fractures as well as layering in determining fracture patterns.

  14. Fracture-permeability behavior of shale

    SciTech Connect (OSTI)

    Carey, J. William; Lei, Zhou; Rougier, Esteban; Mori, Hiroko; Viswanathan, Hari

    2015-05-08

    The fracture-permeability behavior of Utica shale, an important play for shale gas and oil, was investigated using a triaxial coreflood device and X-ray tomography in combination with finite-discrete element modeling (FDEM). Fractures generated in both compression and in a direct-shear configuration allowed permeability to be measured across the faces of cylindrical core. Shale with bedding planes perpendicular to direct-shear loading developed complex fracture networks and peak permeability of 30 mD that fell to 5 mD under hydrostatic conditions. Shale with bedding planes parallel to shear loading developed simple fractures with peak permeability as high as 900 mD. In addition to the large anisotropy in fracture permeability, the amount of deformation required to initiate fractures was greater for perpendicular layering (about 1% versus 0.4%), and in both cases activation of existing fractures are more likely sources of permeability in shale gas plays or damaged caprock in CO? sequestration because of the significant deformation required to form new fracture networks. FDEM numerical simulations were able to replicate the main features of the fracturing processes while showing the importance of fluid penetration into fractures as well as layering in determining fracture patterns.

  15. Fracture-permeability behavior of shale

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Carey, J. William; Lei, Zhou; Rougier, Esteban; Mori, Hiroko; Viswanathan, Hari

    2015-05-08

    The fracture-permeability behavior of Utica shale, an important play for shale gas and oil, was investigated using a triaxial coreflood device and X-ray tomography in combination with finite-discrete element modeling (FDEM). Fractures generated in both compression and in a direct-shear configuration allowed permeability to be measured across the faces of cylindrical core. Shale with bedding planes perpendicular to direct-shear loading developed complex fracture networks and peak permeability of 30 mD that fell to 5 mD under hydrostatic conditions. Shale with bedding planes parallel to shear loading developed simple fractures with peak permeability as high as 900 mD. In addition tomore » the large anisotropy in fracture permeability, the amount of deformation required to initiate fractures was greater for perpendicular layering (about 1% versus 0.4%), and in both cases activation of existing fractures are more likely sources of permeability in shale gas plays or damaged caprock in CO₂ sequestration because of the significant deformation required to form new fracture networks. FDEM numerical simulations were able to replicate the main features of the fracturing processes while showing the importance of fluid penetration into fractures as well as layering in determining fracture patterns.« less

  16. Method for enhancement of sequential hydraulic fracturing using control pulse fracturing

    SciTech Connect (OSTI)

    Jennings, A.R. Jr.; Strubhar, M.K.

    1993-07-20

    A method is described for creating multiple sequential hydraulic fractures via hydraulic fracturing combined with controlled pulse fracturing where two wells are utilized comprising: (a) drilling and completing a first and second well so that the wells will be in fluid communication with each other after subsequent fracturing in each well; (b) creating more than two simultaneous multiple vertical fractures via a controlled pulse fracturing method in the second well; (c) thereafter hydraulically fracturing the reservoir via the first well thereby creating fractures in the reservoir and afterwards shutting-in the first well without any induced pressure; (d) applying thereafter hydraulic pressure to the reservoir via the second well in an amount sufficient to fracture the reservoir thereby forming a first hydraulic fracture perpendicular to the least principal in-situ stress; (e) maintaining the hydraulic pressure on the reservoir while pumping via the second well alternate slugs of a thin-fluid spacer and a temporary blocking agent having a proppant therein whereupon a second hydraulic fracture is initiated; (f) maintaining the hydraulic pressure on the second well while pumping alternate slugs of spacer and blocking agent into the second hydraulic fracture thereby causing the second hydraulic fracture to propagate away from the first hydraulic fracture in step (e) in a curved trajectory which intersects a fracture created in the first well; (g) maintaining the hydraulic pressure while pumping as in step (f) whereupon another hydraulic fracture initiates causing another curved fracture trajectory to form and intersect the fracture created in the first well; and (h) repeated steps (f) and (g) until a desired number of hydraulic fractures are created which allows a substantial improvement in removing a natural resource from the reservoir.

  17. Contaminants in Vadose Zone Environments

    Broader source: Energy.gov [DOE]

    The Deep Vadose Zone – Applied Field Research Initiative (DVZ-AFRI) partnered with the Vadose Zone Journal to create a special section of the journal's November 2012 issue.

  18. Enterprise Zone | Open Energy Information

    Open Energy Info (EERE)

    Zone Jump to: navigation, search This article is a stub. You can help OpenEI by expanding it. Retrieved from "http:en.openei.orgwindex.php?titleEnterpriseZone&oldid542697"...

  19. Renewable liquid reflecting zone plate

    DOE Patents [OSTI]

    Toor, Arthur; Ryutov, Dmitri D.

    2003-12-09

    A renewable liquid reflecting zone plate. Electrodes are operatively connected to a dielectric liquid in a circular or other arrangement to produce a reflecting zone plate. A system for renewing the liquid uses a penetrable substrate.

  20. Radiant zone heated particulate filter

    DOE Patents [OSTI]

    Gonze, Eugene V [Pinckney, MI

    2011-12-27

    A system includes a particulate matter (PM) filter including an upstream end for receiving exhaust gas and a downstream end. A radiant zoned heater includes N zones, where N is an integer greater than one, wherein each of the N zones includes M sub-zones, where M is an integer greater than or equal to one. A control module selectively activates at least a selected one of the N zones to initiate regeneration in downstream portions of the PM filter from the one of the N zones, restricts exhaust gas flow in a portion of the PM filter that corresponds to the selected one of the N zones, and deactivates non-selected ones of the N zones.

  1. Permeability Calculation in a Fracture Network - 12197

    SciTech Connect (OSTI)

    Lee, Cheo Kyung; Kim, Hyo Won [Handong Global University, 3 Namsong-ri, Heunghae-eub, Buk-gu, Pohang, Kyungbuk, 791-708 (Korea, Republic of); Yim, Sung Paal [Korea Atomic Energy Research Institute, Yusong, Daejon, 305-600 (Korea, Republic of)

    2012-07-01

    Laminar flow of a viscous fluid in the pore space of a saturated fractured rock medium is considered to calculate the effective permeability of the medium. The effective permeability is determined from the flow field which is calculated numerically by using the finite element method. The computation of permeability components is carried out with a few different discretizations for a number of fracture arrangements. Various features such as flow field in the fracture channels, the convergence of permeability, and the variation of permeability among different fracture networks are discussed. The longitudinal permeability in general appears greater than the transverse ones. The former shows minor variations with fracture arrangement whereas the latter appears to be more sensitive to the arrangement. From the calculations of the permeability in a rock medium with a fracture network (two parallel fractures aligned in the direction of 45-deg counterclockwise from the horizontal and two connecting fractures(narrowing, parallel and widening) the following conclusions are drawn. 1. The permeability of fractured medium not only depends on the primary orientation of the main fractures but also is noticeably influenced by the connecting fractures in the medium. 2. The transverse permeability (the permeability in the direction normal to the direction of the externally imposed macro-scale pressure gradient) is only a fraction of the longitudinal one, but is sensitive to the arrangement of the connecting fractures. 3. It is important to figure out the pattern of the fractures that connect (or cross) the main fractures for reliable calculation of the transverse permeability. (authors)

  2. Fault zone structure determined through the analysis of earthquake arrival times

    SciTech Connect (OSTI)

    Michelini, A.

    1991-10-01

    This thesis develops and applies a technique for the simultaneous determination of P and S wave velocity models and hypocenters from a set of arrival times. The velocity models are parameterized in terms of cubic B-splines basis functions which permit the retrieval of smooth models that can be used directly for generation of synthetic seismograms using the ray method. In addition, this type of smoothing limits the rise of instabilities related to the poor resolving power of the data. V{sub P}/V{sub S} ratios calculated from P and S models display generally instabilities related to the different ray-coverages of compressional and shear waves. However, V{sub P}/V{sub S} ratios are important for correct identification of rock types and this study introduces a new methodology based on adding some coupling (i.e., proportionality) between P and S models which stabilizes the V{sub P}/V{sub S} models around some average preset value determined from the data. Tests of the technique with synthetic data show that this additional coupling regularizes effectively the resulting models.

  3. Santa Clara County- Zoning Ordinance

    Broader source: Energy.gov [DOE]

    Santa Clara County's Zoning Ordinance includes standards for wind and solar structures for residential, agricultural, and commercial uses.

  4. Coordinated Fault Tolerance for High-Performance Computing

    SciTech Connect (OSTI)

    Dongarra, Jack; Bosilca, George; et al.

    2013-04-08

    Our work to meet our goal of end-to-end fault tolerance has focused on two areas: (1) improving fault tolerance in various software currently available and widely used throughout the HEC domain and (2) using fault information exchange and coordination to achieve holistic, systemwide fault tolerance and understanding how to design and implement interfaces for integrating fault tolerance features for multiple layers of the software stack—from the application, math libraries, and programming language runtime to other common system software such as jobs schedulers, resource managers, and monitoring tools.

  5. Late Cenozoic fault kinematics and basin development, Calabrian arc, Italy

    SciTech Connect (OSTI)

    Knott, S.D.; Turco, E.

    1988-08-01

    Current views for explaining the present structure of the Calabrian arc emphasize bending or buckling of an initially straight zone by rigid indentation. Although bending has played an important role, bending itself cannot explain all structural features now seen in the arc for the following reasons: (1) across-arc extension is inconsistent with buckling, (2) north-south compression predicted by a bending mechanism to occur in the internal part of a curved mountain belt is not present in the Calabrian arc, and (3) lateral shear occurs throughout the arc, not just along the northern and southern boundaries. The model presented here is based on lateral bending of mantle and lower crust (demonstrated by variation in extension in the Tyrrhenian basin) and semibrittle faulting and block rotation in the upper crust. These two styles of deformation are confined to the upper plate of the Calabrian subduction system. This deformation is considered to have been active from the beginning of extension in the Tyrrhenian basin (late Tortonian) and is still active today (based on Holocene seismicity). Block rotations are a consequence of lateral heterogeneous shear during extension. Therefore, some of the observed rotation of paleo-magnetic declinations may have occurred in areas undergoing extension and not just during thrusting. Inversion of sedimentary basins by block rotation is predicted by the model. The model will be a useful aid in interpreting reflection seismic data and exploring and developing offshore and onshore sedimentary basins in southern Italy.

  6. Fault-related CO2 degassing, geothermics, and fluid flow in southern California basins---Physiochemical evidence and modeling

    SciTech Connect (OSTI)

    Boles, James R.; Garven, Grant

    2015-08-04

    Our studies have had an important impact on societal issues. Experimental and field observations show that CO2 degassing, such as might occur from stored CO2 reservoir gas, can result in significant stable isotopic disequilibrium. In the offshore South Ellwood field of the Santa Barbara channel, we show how oil production has reduced natural seep rates in the area, thereby reducing greenhouse gases. Permeability is calculated to be ~20-30 millidarcys for km-scale fault-focused fluid flow, using changes in natural gas seepage rates from well production, and poroelastic changes in formation pore-water pressure. In the Los Angeles (LA) basin, our characterization of formation water chemistry, including stable isotopic studies, allows the distinction between deep and shallow formations waters. Our multiphase computational-based modeling of petroleum migration demonstrates the important role of major faults on geological-scale fluid migration in the LA basin, and show how petroleum was dammed up against the Newport-Inglewood fault zone in a “geologically fast” interval of time (less than 0.5 million years). Furthermore, these fluid studies also will allow evaluation of potential cross-formational mixing of formation fluids. Lastly, our new study of helium isotopes in the LA basin shows a significant leakage of mantle helium along the Newport Inglewood fault zone (NIFZ), at flow rates up to 2 cm/yr. Crustal-scale fault permeability (~60 microdarcys) and advective versus conductive heat transport rates have been estimated using the observed helium isotopic data. The NIFZ is an important deep-seated fault that may crosscut a proposed basin decollement fault in this heavily populated area, and appears to allow seepage of helium from the mantle sources about 30 km beneath Los Angeles. The helium study has been widely cited in recent weeks by the news media, both in radio and on numerous web sites.

  7. Summary of three dimensional pump testing of a fractured rock aquifer in the western Siberian Basin

    SciTech Connect (OSTI)

    Nichols, R.L.; Looney, B.B.; Eddy-Dilek, C.A.; Drozhko, E.G.; Glalolenko, Y.V.; Mokrov, Y.G.; Ivanov, I.A.; Glagolev, A.V.; Vasil`kova, N.A.

    1996-10-30

    A group of scientists from the Savannah River Technology Center and Russia successfully completed a 17 day field investigation of a fractured rock aquifer at the MAYAK PA nuclear production facility in Russia. The test site is located in the western Siberian Basin near the floodplain of the Mishelyak river. The fractured rock aquifer is composed of orphyrites, tuff, tuffbreccia and lava and is overlain by 0.5--12 meters of elluvial and alluvial sediments. A network of 3 uncased wells (176, 1/96, and 2/96) was used to conduct the tests. Wells 176 and 2/96 were used as observation wells and the centrally located well 1/96 was used as the pumping well. Six packers were installed and inflated in each of the observation wells at a depth of up to 85 meters. The use of 6 packers in each well resulted in isolating 7 zones for monitoring. The packers were inflated to different pressures to accommodate the increasing hydrostatic pressure. A straddle packer assembly was installed in the pumping well to allow testing of each of the individual zones isolated in the observation wells. A constant rate pumping test was run on each of the 7 zones. The results of the pumping tests are included in Appendix A. The test provided new information about the nature of the fractured rock aquifers in the vicinity of the Mishelyak river and will be key information in understanding the behavior of contaminants originating from process wastes discharged to Lake Karachi. Results from the tests will be analyzed to determine the hydraulic properties of different zones within the fractured rock aquifer and to determine the most cost effective clean-up approach for the site.

  8. Natural fracture characterization using passive seismic illumination

    SciTech Connect (OSTI)

    Nihei, K.T.

    2003-01-08

    The presence of natural fractures in reservoir rock can significantly enhance gas production, especially in tight gas formations. Any general knowledge of the existence, location, orientation, spatial density, and connectivity of natural fractures, as well as general reservoir structure, that can be obtained prior to active seismic acquisition and drilling can be exploited to identify key areas for subsequent higher resolution active seismic imaging. Current practices for estimating fracture properties before the acquisition of surface seismic data are usually based on the assumed geology and tectonics of the region, and empirical or fracture mechanics-based relationships between stratigraphic curvature and fracturing. The objective of this research is to investigate the potential of multicomponent surface sensor arrays, and passive seismic sources in the form of local earthquakes to identify and characterize potential fractured gas reservoirs located near seismically active regions. To assess the feasibility of passive seismic fracture detection and characterization, we have developed numerical codes for modeling elastic wave propagation in reservoir structures containing multiple, finite-length fractures. This article describes our efforts to determine the conditions for favorable excitation of fracture converted waves, and to develop an imaging method that can be used to locate and characterize fractures using multicomponent, passive seismic data recorded on a surface array.

  9. Statistical Fault Detection & Diagnosis Expert System

    Energy Science and Technology Software Center (OSTI)

    1996-12-18

    STATMON is an expert system that performs real-time fault detection and diagnosis of redundant sensors in any industrial process requiring high reliability. After a training period performed during normal operation, the expert system monitors the statistical properties of the incoming signals using a pattern recognition test. If the test determines that statistical properties of the signals have changed, the expert system performs a sequence of logical steps to determine which sensor or machine component hasmoredegraded.less

  10. Liquid zone seal

    DOE Patents [OSTI]

    Klebanoff, Leonard E.

    2001-01-01

    A seal assembly that provides a means for establishing multiple pressure zones within a system. The seal assembly combines a plate extending from the inner wall of a housing or inner enclosure that intersects with and is immersed in the fluid contained in a well formed in a tray contained within the enclosure. The fluid is a low vapor pressure oil, chemically inert and oxidation resistant. The use of a fluid as the sealing component provides a seal that is self-healing and mechanically robust not subject to normal mechanical wear, breakage, and formation of cracks or pinholes and decouples external mechanical vibrations from internal structural members.

  11. Undulator Hall Air Temperature Fault Scenarios

    SciTech Connect (OSTI)

    Sevilla, J.; Welch, J.; ,

    2010-11-17

    Recent experience indicates that the LCLS undulator segments must not, at any time following tuning, be allowed to change temperature by more than about {+-}2.5 C or the magnetic center will irreversibly shift outside of acceptable tolerances. This vulnerability raises a concern that under fault conditions the ambient temperature in the Undulator Hall might go outside of the safe range and potentially could require removal and retuning of all the segments. In this note we estimate changes that can be expected in the Undulator Hall air temperature for three fault scenarios: (1) System-wide power failure; (2) Heating Ventilation and Air Conditioning (HVAC) system shutdown; and (3) HVAC system temperature regulation fault. We find that for either a system-wide power failure or an HVAC system shutdown (with the technical equipment left on), the short-term temperature changes of the air would be modest due to the ability of the walls and floor to act as a heat ballast. No action would be needed to protect the undulator system in the event of a system-wide power failure. Some action to adjust the heat balance, in the case of the HVAC power failure with the equipment left on, might be desirable but is not required. On the other hand, a temperature regulation failure of the HVAC system can quickly cause large excursions in air temperature and prompt action would be required to avoid damage to the undulator system.

  12. Apparatus and method for monitoring underground fracturing

    DOE Patents [OSTI]

    Warpinski, Norman R.; Steinfort, Terry D.; Branagan, Paul T.; Wilmer, Roy H.

    1999-08-10

    An apparatus and method for measuring deformation of a rock mass around the vicinity of a fracture, commonly induced by hydraulic fracturing is provided. To this end, a well is drilled offset from the proposed fracture region, if no existing well is present. Once the well is formed to a depth approximately equal or exceeding the depth of the proposed fracture, a plurality of inclinometers, for example tiltmeters, are inserted downhole in the well. The inclinometers are located both above and below the approximate depth of the proposed fracture. The plurality of inclinometers may be arranged on a wireline that may be retrieved from the downhole portion of the well and used again or, alternatively, the inclinometers may be cemented in place. In either event, the inclinometers are used to measure the deformation of the rock around the induced fracture.

  13. Apparatus and method for monitoring underground fracturing

    DOE Patents [OSTI]

    Warpinski, N.R.; Steinfort, T.D.; Branagan, P.T.; Wilmer, R.H.

    1999-08-10

    An apparatus and method for measuring deformation of a rock mass around the vicinity of a fracture, commonly induced by hydraulic fracturing is provided. To this end, a well is drilled offset from the proposed fracture region, if no existing well is present. Once the well is formed to a depth approximately equal or exceeding the depth of the proposed fracture, a plurality of inclinometers, for example tiltmeters, are inserted downhole in the well. The inclinometers are located both above and below the approximate depth of the proposed fracture. The plurality of inclinometers may be arranged on a wireline that may be retrieved from the downhole portion of the well and used again or, alternatively, the inclinometers may be cemented in place. In either event, the inclinometers are used to measure the deformation of the rock around the induced fracture. 13 figs.

  14. Calculating the probability of injected carbon dioxide plumes encountering faults

    SciTech Connect (OSTI)

    Jordan, P.D.

    2011-04-01

    One of the main concerns of storage in saline aquifers is leakage via faults. In the early stages of site selection, site-specific fault coverages are often not available for these aquifers. This necessitates a method using available fault data to estimate the probability of injected carbon dioxide encountering and migrating up a fault. The probability of encounter can be calculated from areal fault density statistics from available data, and carbon dioxide plume dimensions from numerical simulation. Given a number of assumptions, the dimension of the plume perpendicular to a fault times the areal density of faults with offsets greater than some threshold of interest provides probability of the plume encountering such a fault. Application of this result to a previously planned large-scale pilot injection in the southern portion of the San Joaquin Basin yielded a 3% and 7% chance of the plume encountering a fully and half seal offsetting fault, respectively. Subsequently available data indicated a half seal-offsetting fault at a distance from the injection well that implied a 20% probability of encounter for a plume sufficiently large to reach it.

  15. Final Report - Advanced Conceptual Models for Unsaturated and Two-Phase Flow in Fractured Rock

    SciTech Connect (OSTI)

    Nicholl, Michael J.

    2006-07-10

    The Department of Energy Environmental Management Program is faced with two major issues involving two-phase flow in fractured rock; specifically, transport of dissolved contaminants in the Vadose Zone, and the fate of Dense Nonaqueous Phase Liquids (DNAPLs) below the water table. Conceptual models currently used to address these problems do not correctly include the influence of the fractures, thus leading to erroneous predictions. Recent work has shown that it is crucial to understand the topology, or ''structure'' of the fluid phases (air/water or water/DNAPL) within the subsurface. It has also been shown that even under steady boundary conditions, the influence of fractures can lead to complex and dynamic phase structure that controls system behavior, with or without the presence of a porous rock matrix. Complicated phase structures within the fracture network can facilitate rapid transport, and lead to a sparsely populated and widespread distribution of concentrated contaminants; these qualities are highly difficult to describe with current conceptual models. The focus of our work is to improve predictive modeling through the development of advanced conceptual models for two-phase flow in fractured rock.

  16. The Influence of fold and fracture development on reservoir behavior of the Lisburne Group of northern Alaska

    SciTech Connect (OSTI)

    Wesley K. Wallace; Catherine L. Hanks; Jerry Jensen: Michael T. Whalen; Paul Atkinson; Joseph Brinton; Thang Bui; Margarete Jadamec; Alexandre Karpov; John Lorenz; Michelle M. McGee; T.M. Parris; Ryan Shackleton

    2004-07-01

    The Carboniferous Lisburne Group is a major carbonate reservoir unit in northern Alaska. The Lisburne is folded and thrust faulted where it is exposed throughout the Brooks Range, but is relatively undeformed in areas of current production in the subsurface of the North Slope. The objectives of this study were to develop a better understanding of four major aspects of the Lisburne: (1) The geometry and kinematics of folds and their truncation by thrust faults. (2) The influence of folding on fracture patterns. (3) The influence of deformation on fluid flow. (4) Lithostratigraphy and its influence on folding, faulting, fracturing, and reservoir characteristics. Symmetrical detachment folds characterize the Lisburne in the northeastern Brooks Range. In contrast, Lisburne in the main axis of the Brooks Range is deformed into imbricate thrust sheets with asymmetrical hangingwall anticlines and footwall synclines. The Continental Divide thrust front separates these different structural styles in the Lisburne and also marks the southern boundary of the northeastern Brooks Range. Field studies were conducted for this project during 1999 to 2001 in various locations in the northeastern Brooks Range and in the vicinity of Porcupine Lake, immediately south of the Continental Divide thrust front. Results are summarized below for the four main subject areas of the study.

  17. MOSSFRAC: An anisotropic 3D fracture model

    SciTech Connect (OSTI)

    Moss, W C; Levatin, J L

    2006-08-14

    Despite the intense effort for nearly half a century to construct detailed numerical models of plastic flow and plastic damage accumulation, models for describing fracture, an equally important damage mechanism still cannot describe basic fracture phenomena. Typical fracture models set the stress tensor to zero for tensile fracture and set the deviatoric stress tensor to zero for compressive fracture. One consequence is that the simple case of the tensile fracture of a cylinder under combined compressive radial and tensile axial loads is not modeled correctly. The experimental result is a cylinder that can support compressive radial loads, but no axial load, whereas, the typical numerical result is a cylinder with all stresses equal to zero. This incorrect modeling of fracture locally also has a global effect, because material that is fracturing produces stress release waves, which propagate from the fracture and influence the surrounding material. Consequently, it would be useful to have a model that can describe the stress relief and the resulting anisotropy due to fracture. MOSSFRAC is a material model that simulates three-dimensional tensile and shear fracture in initially isotropic elastic-plastic materials, although its framework is also amenable to initially anisotropic materials. It differs from other models by accounting for the effects of cracks on the constitutive response of the material, so that the previously described experiment, as well as complicated fracture scenarios are simulated more accurately. The model is implemented currently in the LLNL hydrocodes DYNA3D, PARADYN, and ALE3D. The purpose of this technical note is to present a complete qualitative description of the model and quantitative descriptions of salient features.

  18. Faults and gravity anomalies over the East Mesa hydrothermal-geothermal system

    SciTech Connect (OSTI)

    Goldstein, N.E.; Carle, S.

    1986-05-01

    Detailed interpretations of gravity anomalies over geothermal systems may be extremely useful for mapping the fracture or fault systems that control the circulation of the thermal waters. This approach seems to be particularly applicable in areas like the Salton Trough where reactions between the thermal waters and the porous sediments produce authigenic-hydrothermal minerals in sufficient quantity to cause distinct gravity anomalies at the surface. A 3-D inversion of the residual Bouguer gravity anomaly over the East Mesa geothermal field was made to examine the densified volume of rock. We show that the data not only resolve a north-south and an intersecting northwest structure, but that it may be possible to distinguish between the active present-day hydrothermal system and an older and cooler part of the system. The densified region is compared spatially to self-potential, thermal and seismic results and we find a good concordance between the different geophysical data sets. Our results agree with previous studies that have indicated that the main feeder fault recharging the East Mesa reservoir dips steeply to the west.

  19. Detecting Fractures Using Technology at High Temperatures and Depths -

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    Geothermal Ultrasonic Fracture Imager (GUFI); 2010 Geothermal Technology Program Peer Review Report | Department of Energy Detecting Fractures Using Technology at High Temperatures and Depths - Geothermal Ultrasonic Fracture Imager (GUFI); 2010 Geothermal Technology Program Peer Review Report Detecting Fractures Using Technology at High Temperatures and Depths - Geothermal Ultrasonic Fracture Imager (GUFI); 2010 Geothermal Technology Program Peer Review Report DOE 2010 Geothermal

  20. Method of fracturing a geological formation

    DOE Patents [OSTI]

    Johnson, James O.

    1990-01-01

    An improved method of fracturing a geological formation surrounding a well bore is disclosed. A relatively small explosive charge is emplaced in a well bore and the bore is subsequently hydraulically pressurized to a pressure less than the formation breakdown pressure and preferably greater than the fracture propagation pressure of the formation. The charge is denoted while the bore is so pressurized, resulting in the formation of multiple fractures in the surrounding formation with little or no accompanying formation damage. Subsequent hydraulic pressurization can be used to propagate and extend the fractures in a conventional manner. The method is useful for stimulating production of oil, gas and possibly water from suitable geologic formations.

  1. Microseismic Tracer Particles for Hydraulic Fracturing

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    large increase in the use of hydraulic fracture stimulation of these inherently low permeability reservoir rocks. Operators and service companies require data that can be used to...

  2. Hydraulic Fracturing Technology | Department of Energy

    Energy Savers [EERE]

    Hydraulic fracturing is a technique in which large volumes of water and sand, and small volumes of chemical additives are injected into low-permeability subsurface formations to ...

  3. A compendium of fracture flow models, 1994

    SciTech Connect (OSTI)

    Diodato, D.M.

    1994-11-01

    The report is designed to be used as a decision-making aid for individuals who need to simulate fluid flow in fractured porous media. Fracture flow codes of varying capability in the public and private domain were identified in a survey of government, academia, and industry. The selection and use of an appropriate code requires conceptualization of the geology, physics, and chemistry (for transport) of the fracture flow problem to be solved. Conceptual models that have been invoked to describe fluid flow in fractured porous media include explicit discrete fracture, dual continuum (porosity and/or permeability), discrete fracture network, multiple interacting continua, multipermeability/multiporosity, and single equivalent continuum. The explicit discrete-fracture model is a ``near-field`` representation, the single equivalent continuum model is a ``far-field`` representation, and the dual-continuum model is intermediate to those end members. Of these, the dual-continuum model is the most widely employed. The concept of multiple interacting continua has been applied in a limited number of examples. Multipermeability/multiporosity provides a unified conceptual model. The ability to accurately describe fracture flow phenomena will continue to improve as a result of advances in fracture flow research and computing technology. This improvement will result in enhanced capability to protect the public environment, safety, and health.

  4. Breathing zone air sampler

    DOE Patents [OSTI]

    Tobin, John

    1989-01-01

    A sampling apparatus is provided which comprises a sampler for sampling air in the breathing zone of a wearer of the apparatus and a support for the sampler preferably in the form of a pair of eyeglasses. The sampler comprises a sampling assembly supported on the frame of the eyeglasses and including a pair of sample transport tubes which are suspended, in use, centrally of the frame so as to be disposed on opposite sides of the nose of the wearer and which each include an inlet therein that, in use, is disposed adjacent to a respective nostril of the nose of the wearer. A filter holder connected to sample transport tubes supports a removable filter for filtering out particulate material in the air sampled by the apparatus. The sample apparatus is connected to a pump for drawing air into the apparatus through the tube inlets so that the air passes through the filter.

  5. Deep Vadose Zone - Hanford Site

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Documents Deep Vadose Zone Documents Documents Hanford Site Cleanup Completion Framework Tri-Party Agreement Freedom of Information and Privacy Act Hanford Site Budget Hanford Site Safety Standards DOE - ORP Contracts/Procurements DOE - RL Contracts/Procurements Integrated Waste Feed Delivery Plan Single-Shell Tank Evaluations Deep Vadose Zone 100-F RI/FS Sitewide Probabilistic Seismic Hazard Analysis Environmental Deep Vadose Zone Email Email Page | Print Print Page |Text Increase Font Size

  6. Properties of the extra stage cube under multiple faults

    SciTech Connect (OSTI)

    Adams, G.B., III; Siegel, H.J.

    1982-01-01

    The extra stage cube (ESC) interconnection network, a fault tolerant structure, has been proposed for use in large-scale parallel and distributed systems. It has all of the interconnecting capabilities of the multistage cube-type networks that have been proposed for many systems, and the ESC provides fault tolerance for any single failure. The paper examines the ability of the ESC to operate with multiple faults. 9 references.

  7. Subduction Zone | Open Energy Information

    Open Energy Info (EERE)

    25,000,000 W 25,000,000,000 mW 0.025 GW 2.5e-5 TW 513.15 K240 C 464 F 923.67 R Bac-Man Laguna Geothermal Area Philippine Island Arc Fault Intersection Volcanic 150 MW150,000...

  8. City of Austin- Zoning Code

    Broader source: Energy.gov [DOE]

    The Zoning Code also allows for preservation plans in historic districts to incorporate sustainability measures such as solar technologies and other energy generation and efficiency measures.

  9. Sandia defines solar variability zones

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    defines solar variability zones - Sandia Energy Energy Search Icon Sandia Home Locations ... Stationary Power Energy Conversion Efficiency Solar Energy Wind Energy Water Power ...

  10. Western Renewable Energy Zones (Presentation)

    SciTech Connect (OSTI)

    Hein, J.

    2011-06-01

    This presentation summarizes recent developments and trends pertaining to competitive renewable energy zones, transmission planning and the integration of renewable generation resources.

  11. Effects of Volcanism, Crustal Thickness, and Large Scale Faulting...

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    Effects of Volcanism, Crustal Thickness, and Large Scale Faulting on the Development and Evolution of Geothermal Systems: Collaborative Project in Chile Effects of Volcanism, ...

  12. Active Fault Segments As Potential Earthquake Sources- Inferences...

    Open Energy Info (EERE)

    Segments As Potential Earthquake Sources- Inferences From Integrated Geophysical Mapping Of The Magadi Fault System, Southern Kenya Rift Jump to: navigation, search OpenEI...

  13. Cluster-based architecture for fault-tolerant quantum computation...

    Office of Scientific and Technical Information (OSTI)

    Cluster-based architecture for fault-tolerant quantum computation Citation Details ... Resource Relation: Journal Name: Physical Review. A; Journal Volume: 81; Journal Issue: 4; ...

  14. Dating of major normal fault systems using thermochronology-...

    Open Energy Info (EERE)

    Dating of major normal fault systems using thermochronology- An example from the Raft River detachment, Basin and Range, western United States Jump to: navigation, search OpenEI...

  15. Fault Mapping At Raft River Geothermal Area (1993) | Open Energy...

    Open Energy Info (EERE)

    Raft River Geothermal Area (1993) Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Exploration Activity: Fault Mapping At Raft River Geothermal Area (1993) Exploration...

  16. Recency of Faulting and Neotectonic Framework in the Dixie Valley...

    Open Energy Info (EERE)

    by active geothermal springs. More specifically, our investigation shows that induced stress concentrations at the endpoints of normal fault ruptures appear to promote favorable...

  17. Asking the right questions: benchmarking fault-tolerant extreme...

    Office of Scientific and Technical Information (OSTI)

    Title: Asking the right questions: benchmarking fault-tolerant extreme-scale systems. Abstract not provided. Authors: Widener, Patrick ; Ferreira, Kurt Brian ; Levy, Scott N. ; ...

  18. Understanding Fault Characteristics And Sediment Depth For Geothermal...

    Open Energy Info (EERE)

    Understanding Fault Characteristics And Sediment Depth For Geothermal Exploration Using 3D Gravity Inversion In Walker Valley, Nevada Jump to: navigation, search OpenEI Reference...

  19. Upper crustal faulting in an obliquely extending orogen, structural...

    Open Energy Info (EERE)

    faulting in an obliquely extending orogen, structural control on permeability and production in the Coso Geothermal Field, eastern California Jump to: navigation, search OpenEI...

  20. Active Fault Controls At High-Temperature Geothermal Sites- Prospectin...

    Open Energy Info (EERE)

    model in which recently active (Holocene) faults are preferred conduits for migration of thermal water from deep crustal depths, and we infer that the detection of sites...

  1. Hydrologic characterization of fractured rocks: An interdisciplinary methodology

    SciTech Connect (OSTI)

    Long, J.C.S.; Majer, E.L.; Martel, S.J.; Karasaki, K.; Peterson, J.E. Jr.; Davey, A.; Hestir, K. )

    1990-11-01

    The characterization of fractured rock is a critical problem in the development of nuclear waste repositories in geologic media. A good methodology for characterizing these systems should be focused on the large important features first and concentrate on building numerical models which can reproduce the observed hydrologic behavior of the fracture system. In many rocks, fracture zones dominate the behavior. These can be described using the tools of geology and geomechanics in order to understand what kind of features might be important hydrologically and to qualitatively describe the way flow might occur in the rock. Geophysics can then be employed to locate these features between boreholes. Then well testing can be used to see if the identified features are in fact important. Given this information, a conceptual model of the system can be developed which honors the geologic description, the tomographic data and the evidence of high permeability. Such a model can then be modified through an inverse process, such as simulated annealing, until it reproduces the cross-hole well test behavior which has been observed insitu. Other possible inversion techniques might take advantage of self similar structure. Once a model is constructed, we need to see how well the model makes predictions. We can use a cross-validation technique which sequentially puts aside parts of the data and uses the model to predict that part in order to calculate the prediction error. This approach combines many types of information in a methodology which can be modified to fit a particular field site. 114 refs., 81 figs., 7 tabs.

  2. Superconducting fault current controller/current controller

    DOE Patents [OSTI]

    Cha, Yung S.

    2004-06-15

    A superconducting fault current controller/current controller employs a superconducting-shielded core reactor (SSCR) with a variable impedance in a secondary circuit to control current in a primary circuit such as an electrical distribution system. In a second embodiment, a variable current source is employed in a secondary circuit of an SSCR to control current in the primary circuit. In a third embodiment, both a variable impedance in one secondary circuit and a variable current source in a second circuit of an SSCR are employed for separate and independent control of current in the primary circuit.

  3. Statistical Fault Detection & Diagnosis Expert System

    Energy Science and Technology Software Center (OSTI)

    1996-12-18

    STATMON is an expert system that performs real-time fault detection and diagnosis of redundant sensors in any industrial process requiring high reliability. After a training period performed during normal operation, the expert system monitors the statistical properties of the incoming signals using a pattern recognition test. If the test determines that statistical properties of the signals have changed, the expert system performs a sequence of logical steps to determine which sensor or machine component hasmore » degraded.« less

  4. Geothermal Well Stimulated Using High Energy Gas Fracturing

    SciTech Connect (OSTI)

    Chu, T.Y.; Jacobson, R.D.; Warpinski, N.; Mohaupt, Henry

    1987-01-20

    This paper reports the result of an experimental study of the High Energy Gas Fracturing (HEGF) technique for geothermal well stimulation. These experiments demonstrated that multiple fractures could be created to link a water-filled borehole with other fractures. The resulting fracture network and fracture interconnections were characterized by flow tests as well as mine back. Commercial oil field fracturing tools were used successfully in these experiments. 5 refs., 2 tabs., 5 figs.

  5. Fracture of solid state laser slabs

    SciTech Connect (OSTI)

    Marion, J.E.

    1986-07-01

    Fracture due to thermal stress limits the power output potential of modern, high average power slab lasers. Here the criteria for slab fracture and the nature of the surface flaws which constitute the strength-controlling defects are reviewed. Specific fracture data for gadolinium scandium gallium garnet and LHG-5 phosphate glass with different surface finishes are evaluated in the context of assigning appropriate slab operating parameters using Wiebull statistics. These examples illustrate both the danger of design using brittle components without adequate fracture testing, and the inadequacy of design methods which use a fixed safety factor, for this class of materials. Further consideration reveals that operation of slab lasers in contact with an aqueous coolant may lead to strength degradation with time. Finally, the evolution of the failure process in which a characteristic midplane crack forms is outlined, and the pertinent parameters for avoiding slab fracture are identified.

  6. New proppant for deep hydraulic fracturing

    SciTech Connect (OSTI)

    Das, K.; Underdown, D.R.

    1985-01-01

    Much work has focused on developing and evaluating various materials for use as proppants for hydraulic fracturing. Sand is used most often as a fracturing proppant in shallow wells. Deep wells with high closure stresses require a proppant, such as sintered bauxite, that will not crush under adverse conditions. Ceramic and zirconium oxide beads and resin-coated sand proppants also have been developed for deep hydraulic fracturing. A new fracturing proppant has been developed that exhibits the properties necessary for use in deep hydraulic fracturing. This proppant is produced by precuring a specially modified phenolformaldehyde resin onto sand. The new proppant maintains conductivity and resists crushing much better than does sand. The new proppant was compared to intermediate-density sintered bauxitic proppants and cured-in-place proppants and the tests were confirmed by an independent laboratory.

  7. Scale-Dependent Fracture-Matrix Interactions and Their Impact...

    Office of Scientific and Technical Information (OSTI)

    ... network models with variability in apertures across a network of fractures and within individual fractures. less Authors: Rajaram, Harihar 1 ; Brutz, Michael 1 ; Klein, ...

  8. Controlling Subsurface Fractures and Fluid Flow: A Basic Research...

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    Controlling Subsurface Fractures and Fluid Flow: A Basic Research Agenda Controlling Subsurface Fractures and Fluid Flow: A Basic Research Agenda PDF icon BES Report Controlling ...

  9. Colloid-Facilitated Transport of Cations in an Unsaturated Fractured...

    Office of Scientific and Technical Information (OSTI)

    Colloid-facilitated mobilization of cesium and strontium was important at low ionic strength in fractures where slow flow allowed greater exchange of flow between the fractures and ...

  10. Unusual lithiation and fracture behavior of silicon mesoscale...

    Office of Scientific and Technical Information (OSTI)

    Unusual lithiation and fracture behavior of silicon mesoscale pillars: roles of ultrathin ... Citation Details In-Document Search Title: Unusual lithiation and fracture behavior of ...

  11. Images of Fracture Sustainability Test on Stripa Granite

    DOE Data Explorer [Office of Scientific and Technical Information (OSTI)]

    Tim Kneafsey

    2014-05-11

    Images of the Stripa Granite core before and after the fracture sustainability test. Photos of fracture faces of Stripa Granite core.

  12. A Research Park for Studying Processes in Unsaturated Fractured...

    Office of Scientific and Technical Information (OSTI)

    A Research Park for Studying Processes in Unsaturated Fractured Media Citation Details In-Document Search Title: A Research Park for Studying Processes in Unsaturated Fractured ...

  13. Fractured rock stress-permeability relationships from in situ...

    Office of Scientific and Technical Information (OSTI)

    Fractured rock stress-permeability relationships from in situ data and effects of temperature and chemical-mechanical couplings Citation Details In-Document Search Title: Fractured...

  14. Stress-dependent permeability of fractured rock masses: A numerical...

    Office of Scientific and Technical Information (OSTI)

    permeability of fractured rock masses: A numerical study Citation Details In-Document Search Title: Stress-dependent permeability of fractured rock masses: A numerical study We ...

  15. Three-dimensional Modeling of Fracture Clusters in Geothermal...

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    of Fracture Clusters in Geothermal Reservoirs; 2010 Geothermal Technology Program Peer Review Report Three-dimensional Modeling of Fracture Clusters in Geothermal Reservoirs;...

  16. Detection and Characterization of Natural and Induced Fractures...

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    Detection and Characterization of Natural and Induced Fractures for the Development of Enhanced Geothermal Systems Detection and Characterization of Natural and Induced Fractures for ...

  17. Fracture mechanics based design for radioactive material transport...

    Office of Scientific and Technical Information (OSTI)

    Fracture mechanics based design for radioactive material transport packagings -- Historical review Citation Details In-Document Search Title: Fracture mechanics based design for ...

  18. Characterizing Fractures in the Geysers Geothermal Field by Micro...

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    Fractures in the Geysers Geothermal Field by Micro-seismic Data, Using Soft Computing, Fractals, and Shear Wave Anisotropy Characterizing Fractures in the Geysers Geothermal Field...

  19. Irradiation Effects on Human Cortical Bone Fracture Behavior

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Irradiation Effects on Human Cortical Bone Fracture Behavior Print Human bone is strong but still fallible. To better predict fracturing in bone, researchers need a mechanistic...

  20. Irradiation Effects on Human Cortical Bone Fracture Behavior

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Irradiation Effects on Human Cortical Bone Fracture Behavior Irradiation Effects on Human Cortical Bone Fracture Behavior Print Wednesday, 28 July 2010 00:00 Human bone is strong...

  1. Images of Fracture Sustainability Test on Stripa Granite

    DOE Data Explorer [Office of Scientific and Technical Information (OSTI)]

    Tim Kneafsey

    Images of the Stripa Granite core before and after the fracture sustainability test. Photos of fracture faces of Stripa Granite core.

  2. Fracture Evolution Following a Hydraulic Stimulation within an...

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    Evolution Following a Hydraulic Stimulation within an EGS Reservoir Fracture Evolution Following a Hydraulic Stimulation within an EGS Reservoir Fracture Evolution Following a ...

  3. Preface to the Special Issue on the Sandia Fracture Challenge...

    Office of Scientific and Technical Information (OSTI)

    Journal Article: Preface to the Special Issue on the Sandia Fracture Challenge. Citation Details In-Document Search Title: Preface to the Special Issue on the Sandia Fracture ...

  4. Predicting fracture in micron-scale polycrystalline silicon MEMS...

    Office of Scientific and Technical Information (OSTI)

    Predicting fracture in micron-scale polycrystalline silicon MEMS structures. Citation Details In-Document Search Title: Predicting fracture in micron-scale polycrystalline silicon ...

  5. Hydrogen Assisted Fracture of Stainless Steels (Technical Report...

    Office of Scientific and Technical Information (OSTI)

    Technical Report: Hydrogen Assisted Fracture of Stainless Steels Citation Details In-Document Search Title: Hydrogen Assisted Fracture of Stainless Steels You are accessing a ...

  6. Fracture Propagation, Fluid Flow, and Geomechanics of Water-Based...

    Office of Scientific and Technical Information (OSTI)

    Conference: Fracture Propagation, Fluid Flow, and Geomechanics of Water-Based Hydraulic ... Title: Fracture Propagation, Fluid Flow, and Geomechanics of Water-Based Hydraulic ...

  7. Hydrogen Assisted Fracture of Stainless Steels (Technical Report...

    Office of Scientific and Technical Information (OSTI)

    Hydrogen Assisted Fracture of Stainless Steels Citation Details In-Document Search Title: Hydrogen Assisted Fracture of Stainless Steels Abstract not provided. Authors: Somerday,...

  8. Hydrogen Assisted Fracture of Stainless Steels (Technical Report...

    Office of Scientific and Technical Information (OSTI)

    Hydrogen Assisted Fracture of Stainless Steels Citation Details In-Document Search Title: Hydrogen Assisted Fracture of Stainless Steels You are accessing a document from the...

  9. Fracture-resistant lanthanide scintillators

    DOE Patents [OSTI]

    Doty, F. Patrick

    2011-01-04

    Lanthanide halide alloys have recently enabled scintillating gamma ray spectrometers comparable to room temperature semiconductors (<3% FWHM energy resolutions at 662 keV). However brittle fracture of these materials upon cooling hinders the growth of large volume crystals. Efforts to improve the strength through non-lanthanide alloy substitution, while preserving scintillation, have been demonstrated. Isovalent alloys having nominal compositions of comprising Al, Ga, Sc, Y, and In dopants as well as aliovalent alloys comprising Ca, Sr, Zr, Hf, Zn, and Pb dopants were prepared. All of these alloys exhibit bright fluorescence under UV excitation, with varying shifts in the spectral peaks and intensities relative to pure CeBr.sub.3. Further, these alloys scintillate when coupled to a photomultiplier tube (PMT) and exposed to .sup.137Cs gamma rays.

  10. Fault current limiter with shield and adjacent cores

    DOE Patents [OSTI]

    Darmann, Francis Anthony; Moriconi, Franco; Hodge, Eoin Patrick

    2013-10-22

    In a fault current limiter (FCL) of a saturated core type having at least one coil wound around a high permeability material, a method of suppressing the time derivative of the fault current at the zero current point includes the following step: utilizing an electromagnetic screen or shield around the AC coil to suppress the time derivative current levels during zero current conditions.

  11. Automated Proactive Fault Isolation: A Key to Automated Commissioning

    SciTech Connect (OSTI)

    Katipamula, Srinivas; Brambley, Michael R.

    2007-07-31

    In this paper, we present a generic model for automated continuous commissioing and then delve in detail into one of the processes, proactive testing for fault isolation, which is key to automating commissioning. The automated commissioining process uses passive observation-based fault detction and diagnostic techniques, followed by automated proactive testing for fault isolation, automated fault evaluation, and automated reconfiguration of controls together to continuously keep equipment controlled and running as intended. Only when hard failures occur or a physical replacement is required does the process require human intervention, and then sufficient information is provided by the automated commissioning system to target manual maintenance where it is needed. We then focus on fault isolation by presenting detailed logic that can be used to automatically isolate faults in valves, a common component in HVAC systems, as an example of how automated proactive fault isolation can be accomplished. We conclude the paper with a discussion of how this approach to isolating faults can be applied to other common HVAC components and their automated commmissioning and a summary of key conclusions of the paper.

  12. Folding associated with extensional faulting: Sheep Range detachment, southern Nevada

    SciTech Connect (OSTI)

    Guth, P.L.

    1985-01-01

    The Sheep Range detachment is a major Miocene extensional fault system of the Great Basin. Its major faults have a scoop shape, with straight, N-S traces extending 15-30 km and then abruptly turning to strike E-W. Tertiary deformation involved simultaneous normal faulting, sedimentation, landsliding, and strike-slip faulting. Folds occur in two settings: landslide blocks and drag along major faults. Folds occur in landslide blocks and beneath them. Most folds within landslide blocks are tight anticlines, with limbs dipping 40-60 degrees. Brecciation of the folds and landslide blocks suggests brittle deformation. Near Quijinump Canyon in the Sheep Range, at least three landslide blocks (up to 500 by 1500 m) slid into a small Tertiary basin. Tertiary limestone beneath the Paleozoic blocks was isoclinally folded. Westward dips reveal drag folds along major normal faults, as regional dips are consistently to the east. The Chowderhead anticline is the largest drag fold, along an extensional fault that offsets Ordovician units 8 km. East-dipping Ordovician and Silurian rocks in the Desert Range form the hanging wall. East-dipping Cambrian and Ordovician units in the East Desert Range form the foot wall and east limb of the anticline. Caught along the fault plane, the anticline's west-dipping west limb contains mostly Cambrian units.

  13. All-to-all sequenced fault detection system

    DOE Patents [OSTI]

    Archer, Charles Jens; Pinnow, Kurt Walter; Ratterman, Joseph D.; Smith, Brian Edward

    2010-11-02

    An apparatus, program product and method enable nodal fault detection by sequencing communications between all system nodes. A master node may coordinate communications between two slave nodes before sequencing to and initiating communications between a new pair of slave nodes. The communications may be analyzed to determine the nodal fault.

  14. Automatic Fault Characterization via Abnormality-Enhanced Classification

    SciTech Connect (OSTI)

    Bronevetsky, G; Laguna, I; de Supinski, B R

    2010-12-20

    Enterprise and high-performance computing systems are growing extremely large and complex, employing hundreds to hundreds of thousands of processors and software/hardware stacks built by many people across many organizations. As the growing scale of these machines increases the frequency of faults, system complexity makes these faults difficult to detect and to diagnose. Current system management techniques, which focus primarily on efficient data access and query mechanisms, require system administrators to examine the behavior of various system services manually. Growing system complexity is making this manual process unmanageable: administrators require more effective management tools that can detect faults and help to identify their root causes. System administrators need timely notification when a fault is manifested that includes the type of fault, the time period in which it occurred and the processor on which it originated. Statistical modeling approaches can accurately characterize system behavior. However, the complex effects of system faults make these tools difficult to apply effectively. This paper investigates the application of classification and clustering algorithms to fault detection and characterization. We show experimentally that naively applying these methods achieves poor accuracy. Further, we design novel techniques that combine classification algorithms with information on the abnormality of application behavior to improve detection and characterization accuracy. Our experiments demonstrate that these techniques can detect and characterize faults with 65% accuracy, compared to just 5% accuracy for naive approaches.

  15. Major Normal Fault | Open Energy Information

    Open Energy Info (EERE)

    345,000,000 W 345,000,000,000 mW 0.345 GW 3.45e-4 TW 548.15 K275 C 527 F 986.67 R Java - Darajat Geothermal Area Sunda Volcanic Arc Subduction Zone Volcanics 255 MW255,000 kW...

  16. Characterization of fracture reservoirs using static and dynamic data: From sonic and 3D seismic to permeability distribution. Annual report, March 1, 1996--February 28, 1997

    SciTech Connect (OSTI)

    Parra, J.O.; Collier, H.A.; Owen, T.E.

    1997-06-01

    In low porosity, low permeability zones, natural fractures are the primary source of permeability which affect both production and injection of fluids. The open fractures do not contribute much to porosity, but they provide an increased drainage network to any porosity. They also may connect the borehole to remote zones of better reservoir characteristics. An important approach to characterizing the fracture orientation and fracture permeability of reservoir formations is one based on the effects of such conditions on the propagation of acoustic and seismic waves in the rock. The project is a study directed toward the evaluation of acoustic logging and 3D-seismic measurement techniques as well as fluid flow and transport methods for mapping permeability anisotropy and other petrophysical parameters for the understanding of the reservoir fracture systems and associated fluid dynamics. The principal application of these measurement techniques and methods is to identify and investigate the propagation characteristics of acoustic and seismic waves in the Twin Creek hydrocarbon reservoir owned by Union Pacific Resources (UPR) and to characterize the fracture permeability distribution using production data. This site is located in the overthrust area of Utah and Wyoming. UPR drilled six horizontal wells, and presently UPR has two rigs running with many established drill hole locations. In addition, there are numerous vertical wells that exist in the area as well as 3D seismic surveys. Each horizontal well contains full FMS logs and MWD logs, gamma logs, etc.

  17. Climate Zones | Department of Energy

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    Building America » Climate Zones Climate Zones Building America determines building practices based on climate zones to achieve the most energy savings in a home. This page offers some general guidelines on the definitions of the various climate regions based on heating degree-days, average temperatures, and precipitation. You can also view the Guide to Determining Climate Regions by County. Hot-Humid A hot-humid climate is generally defined as a region that receives more than 20 in. (50 cm) of

  18. Self field triggered superconducting fault current limiter

    DOE Patents [OSTI]

    Tekletsadik, Kasegn D.

    2008-02-19

    A superconducting fault current limiter array with a plurality of superconductor elements arranged in a meanding array having an even number of supconductors parallel to each other and arranged in a plane that is parallel to an odd number of the plurality of superconductors, where the odd number of supconductors are parallel to each other and arranged in a plane that is parallel to the even number of the plurality of superconductors, when viewed from a top view. The even number of superconductors are coupled at the upper end to the upper end of the odd number of superconductors. A plurality of lower shunt coils each coupled to the lower end of each of the even number of superconductors and a plurality of upper shunt coils each coupled to the upper end of each of the odd number of superconductors so as to generate a generally orthoganal uniform magnetic field during quenching using only the magenetic field generated by the superconductors.

  19. Locating hardware faults in a parallel computer

    DOE Patents [OSTI]

    Archer, Charles J.; Megerian, Mark G.; Ratterman, Joseph D.; Smith, Brian E.

    2010-04-13

    Locating hardware faults in a parallel computer, including defining within a tree network of the parallel computer two or more sets of non-overlapping test levels of compute nodes of the network that together include all the data communications links of the network, each non-overlapping test level comprising two or more adjacent tiers of the tree; defining test cells within each non-overlapping test level, each test cell comprising a subtree of the tree including a subtree root compute node and all descendant compute nodes of the subtree root compute node within a non-overlapping test level; performing, separately on each set of non-overlapping test levels, an uplink test on all test cells in a set of non-overlapping test levels; and performing, separately from the uplink tests and separately on each set of non-overlapping test levels, a downlink test on all test cells in a set of non-overlapping test levels.

  20. Online Monitoring System for Performance Fault Detection

    SciTech Connect (OSTI)

    Gioiosa, Roberto; Kestor, Gokcen; Kerbyson, Darren J.

    2014-05-19

    To achieve the exaFLOPS performance within a contain power budget, next supercomputers will feature hundreds of millions of components operating at low- and near-threshold voltage. As the probability that at least one of these components fails during the execution of an application approaches certainty, it seems unrealistic to expect that any run of a scientific application will not experience some performance faults. We believe that there is need of a new generation of light-weight performance and debugging tools that can be used online even during production runs of parallel applications and that can identify performance anomalies during the application execution. In this work we propose the design and implementation of a monitoring system that continuously inspects the evolution of run

  1. Saturated Zone In-Situ Testing

    SciTech Connect (OSTI)

    P. W. Reimus; M. J. Umari

    2003-12-23

    The purpose of this scientific analysis is to document the results and interpretations of field experiments that have been conducted to test and validate conceptual flow and radionuclide transport models in the saturated zone (SZ) near Yucca Mountain. The test interpretations provide estimates of flow and transport parameters that are used in the development of parameter distributions for Total System Performance Assessment (TSPA) calculations. These parameter distributions are documented in the revisions to the SZ flow model report (BSC 2003 [ 162649]), the SZ transport model report (BSC 2003 [ 162419]), the SZ colloid transport report (BSC 2003 [162729]), and the SZ transport model abstraction report (BSC 2003 [1648701]). Specifically, this scientific analysis report provides the following information that contributes to the assessment of the capability of the SZ to serve as a barrier for waste isolation for the Yucca Mountain repository system: (1) The bases for selection of conceptual flow and transport models in the saturated volcanics and the saturated alluvium located near Yucca Mountain. (2) Results and interpretations of hydraulic and tracer tests conducted in saturated fractured volcanics at the C-wells complex near Yucca Mountain. The test interpretations include estimates of hydraulic conductivities, anisotropy in hydraulic conductivity, storativities, total porosities, effective porosities, longitudinal dispersivities, matrix diffusion mass transfer coefficients, matrix diffusion coefficients, fracture apertures, and colloid transport parameters. (3) Results and interpretations of hydraulic and tracer tests conducted in saturated alluvium at the Alluvium Testing Complex (ATC), which is located at the southwestern corner of the Nevada Test Site (NTS). The test interpretations include estimates of hydraulic conductivities, storativities, total porosities, effective porosities, longitudinal dispersivities, matrix diffusion mass transfer coefficients, and colloid transport parameters. (4) Comparisons of sorption parameter estimates for a reactive solute tracer (lithium ion) derived from both the C-wells field tracer tests and laboratory tests using C-wells core samples. (5) Sorption parameter estimates for lithium ion derived from laboratory tests using alluvium samples from NC-EWDP-19D1 (one of the wells at the ATC) so that a comparison of laboratory- and field-derived sorption parameters can be made in saturated alluvium if cross-hole tracer tests are conducted at the ATC.

  2. Fracture porosimeter: a new tool for determining fracture conductivity under downhole stress

    SciTech Connect (OSTI)

    Wendorff, C.L.

    1982-01-01

    This work describes a procedure for determining fracture conductivity at down-hole stresses. The embedment and crushing of proppant between rock samples from a specific formation are measured at closure stresses. The conductivities of fractures propped with various proppants can be determined rather quickly. As a result, the procedure can supply information useful in determining optimum fracture treatment for a specific well. In the procedure, samples of formation and proppants are placed in an appropriate confinement chamber. Closure stresses are applied and fracture conductivity can be calculated. The study includes examples of permeability and surface areas of conventional proppants. Fracture conductivity determinations, made with a variety of formations and proppants, indicate how this procedure can be useful when making decisions concerning fracture treatment design. An improvement in equipment design also is presented. 11 references.

  3. Use of Tracers to Characterize Fractures in Engineered Geothermal Systems

    Broader source: Energy.gov [DOE]

    Project Objectives: Measure interwell fracture surface area and fracture spacing using sorbing tracers; measure fracture surface areas adjacent to a single geothermal well using tracers and injection/backflow techniques; design, fabricate and test a downhole instrument for measuring fracture flow following a hydraulic stimulation experiment.

  4. Climate Zone 1B | Open Energy Information

    Open Energy Info (EERE)

    Zone Subtype B. Climate Zone 1B is defined as Dry with IP Units 9000 < CDD50F and SI Units 5000 < CDD10C . The following places are categorized as class 1B climate zones:...

  5. Cohesive Zone Model User Element

    Energy Science and Technology Software Center (OSTI)

    2007-04-17

    Cohesive Zone Model User Element (CZM UEL) is an implementation of a Cohesive Zone Model as an element for use in finite element simulations. CZM UEL computes a nodal force vector and stiffness matrix from a vector of nodal displacements. It is designed for structural analysts using finite element software to predict crack initiation, crack propagation, and the effect of a crack on the rest of a structure.

  6. Infiltration and Seepage Through Fractured Welded Tuff

    SciTech Connect (OSTI)

    T.A. Ghezzehei; P.F. Dobson; J.A. Rodriguez; P.J. Cook

    2006-06-20

    The Nopal I mine in Pena Blanca, Chihuahua, Mexico, contains a uranium ore deposit within fractured tuff. Previous mining activities exposed a level ground surface 8 m above an excavated mining adit. In this paper, we report results of ongoing research to understand and model percolation through the fractured tuff and seepage into a mined adit both of which are important processes for the performance of the proposed nuclear waste repository at Yucca Mountain. Travel of water plumes was modeled using one-dimensional numerical and analytical approaches. Most of the hydrologic properly estimates were calculated from mean fracture apertures and fracture density. Based on the modeling results, we presented constraints for the arrival time and temporal pattern of seepage at the adit.

  7. Regional Analysis And Characterization Of Fractured Aquifers...

    Open Energy Info (EERE)

    become an important source of basic data that can be used to help characterize the nature and extent of hydraulic conductivity in fractured rocks. We plan to continue to...

  8. Fracture of surface cracks loaded in bending

    SciTech Connect (OSTI)

    Chao, Y.J.; Reuter, W.G.

    1997-12-31

    Theoretical background of the constraint effect in brittle fracture of solids is reviewed. Fracture test data from D6-aC, a high strength steel, using three-point-bend (SE(B)) specimens and surface cracked plate (SC(B)) specimens under bending are presented. It is shown that the SE(B) data has an elevated fracture toughness for increasing a/W, i.e., a crack geometry with a larger T/K corresponds to a higher K{sub c} which is consistent with the theoretical prediction. The fundamental fracture properties, i.e., the critical strain and the critical distance, determined from the SE(B) test data are then applied to the interpretation and prediction of the SC(B) test data. Reasonable agreement is achieved for the crack growth initiation site and the load.

  9. 3-D description of fracture surfaces and stress-sensitivity analysis for naturally fractured reservoirs

    SciTech Connect (OSTI)

    Zhang, S.Q.; Jioa, D.; Meng, Y.F.; Fan, Y.

    1997-08-01

    Three kinds of reservoir cores (limestone, sandstone, and shale with natural fractures) were used to study the effect of morphology of fracture surfaces on stress sensitivity. The cores, obtained from the reservoirs with depths of 2170 to 2300 m, have fractures which are mated on a large scale, but unmated on a fine scale. A specially designed photoelectric scanner with a computer was used to describe the topography of the fracture surfaces. Then, theoretical analysis of the fracture closure was carried out based on the fracture topography generated. The scanning results show that the asperity has almost normal distributions for all three types of samples. For the tested samples, the fracture closure predicted by the elastic-contact theory is different from the laboratory measurements because plastic deformation of the aspirates plays an important role under the testing range of normal stresses. In this work, the traditionally used elastic-contact theory has been modified to better predict the stress sensitivity of reservoir fractures. Analysis shows that the standard deviation of the probability density function of asperity distribution has a great effect on the fracture closure rate.

  10. TRITIUM EFFECTS ON WELDMENT FRACTURE TOUGHNESS

    SciTech Connect (OSTI)

    Morgan, M; Michael Tosten, M; Scott West, S

    2006-07-17

    The effects of tritium on the fracture toughness properties of Type 304L stainless steel and its weldments were measured. Fracture toughness data are needed for assessing tritium reservoir structural integrity. This report provides data from J-Integral fracture toughness tests on unexposed and tritium-exposed weldments. The effect of tritium on weldment toughness has not been measured until now. The data include tests on tritium-exposed weldments after aging for up to three years to measure the effect of increasing decay helium concentration on toughness. The results indicate that Type 304L stainless steel weldments have high fracture toughness and are resistant to tritium aging effects on toughness. For unexposed alloys, weldment fracture toughness was higher than base metal toughness. Tritium-exposed-and-aged base metals and weldments had lower toughness values than unexposed ones but still retained good toughness properties. In both base metals and weldments there was an initial reduction in fracture toughness after tritium exposure but little change in fracture toughness values with increasing helium content in the range tested. Fracture modes occurred by the dimpled rupture process in unexposed and tritium-exposed steels and welds. This corroborates further the resistance of Type 304L steel to tritium embrittlement. This report fulfills the requirements for the FY06 Level 3 milestone, TSR15.3 ''Issue summary report for tritium reservoir material aging studies'' for the Enhanced Surveillance Campaign (ESC). The milestone was in support of ESC L2-1866 Milestone-''Complete an annual Enhanced Surveillance stockpile aging assessment report to support the annual assessment process''.

  11. Poroelastic response of orthotropic fractured porous media

    SciTech Connect (OSTI)

    Berryman, J.G.

    2010-12-01

    An algorithm is presented for inverting either laboratory or field poroelastic data for all the drained constants of an anisotropic (specifically orthotropic) fractured poroelastic system. While fractures normally weaken the system by increasing the mechanical compliance, any liquids present in these fractures are expected to increase the stiffness somewhat, thus negating to some extent the mechanical weakening influence of the fractures themselves. The analysis presented quantifies these effects and shows that the key physical variable needed to account for the pore-fluid effects is a factor of (1 - B), where B is Skempton's second coe#14;fficient and satisfies 0 {<=} #20; B < 1. This scalar factor uniformly reduces the increase in compliance due to the presence of communicating fractures, thereby stiffening the fractured composite medium by a predictable amount. One further goal of the discussion is to determine how many of the poroelastic constants need to be known by other means in order to determine the rest from remote measurements, such as seismic wave propagation data in the field. Quantitative examples arising in the analysis show that, if the fracture aspect ratio a{sub f} ~ 0.1 and the pore fluid is liquid water, then for several cases considered Skempton's B ~ 0:9, so the stiffening effect of the pore-liquid reduces the change in compliance due to the fractures by a factor 1-B ~ 0.1, in these examples. The results do however depend on the actual moduli of the unfractured elastic material, as well as on the pore-liquid bulk modulus, so these quantitative predictions are just examples, and should not be treated as universal results. Attention is also given to two previously unremarked poroelastic identities, both being useful variants of Gassmann's equations for homogeneous -- but anisotropic -- poroelasticity. Relationships to Skempton's analysis of saturated soils are also noted. The paper concludes with a discussion of alternative methods of analyzing and quantifying fluid-substitution behavior in poroelastic systems, especially for those systems having heterogeneous constitution.

  12. Transition Zone Geothermal Region | Open Energy Information

    Open Energy Info (EERE)

    Unknown Planned Capacity 1 Geothermal Areas within the Transition Zone Geothermal Region Energy Generation Facilities within the Transition Zone Geothermal Region Geothermal Power...

  13. GridZone | Open Energy Information

    Open Energy Info (EERE)

    search Name: GridZone Sector: Efficiency, Services, Transmission Technology: Smart Grid, Energy Storage, Energy Security ParentHolding Organization: GridZone Limited Company...

  14. Wetlands and Riparian Zones | Open Energy Information

    Open Energy Info (EERE)

    Wetlands and Riparian Zones Jump to: navigation, search Retrieved from "http:en.openei.orgwindex.php?titleWetlandsandRiparianZones&oldid612217...

  15. Effects of fracture distribution and length scale on the equivalent

    Office of Scientific and Technical Information (OSTI)

    continuum elastic compliance of fractured rock masses (Journal Article) | SciTech Connect Effects of fracture distribution and length scale on the equivalent continuum elastic compliance of fractured rock masses Citation Details In-Document Search Title: Effects of fracture distribution and length scale on the equivalent continuum elastic compliance of fractured rock masses Authors: Gutierrez, Marte ; Youn, Dong-Joon Publication Date: 2015-12-01 OSTI Identifier: 1224355 Grant/Contract

  16. NFFLOW: A reservoir simulator incorporating explicit fractures (SPE 153890)

    SciTech Connect (OSTI)

    Boyle, E.J.; Sams, W.N.

    2012-01-01

    NFFLOW is a research code that quickly and inexpensively simulates flow in moderately fractured reservoirs. It explicitly recognizes fractures separately from rock matrix. In NFFLOW fracture flow is proportional to the pressure gradient along the fracture, and flow in the rock matrix is determined by Darcys Law. The two flow mechanisms are coupled through the pressure gradient between a fracture and its adjacent rock matrix. Presented is a promising change to NFFLOW that allows for flow across a rock matrix block.

  17. SITE-SCALE SATURATED ZONE TRANSPORT

    SciTech Connect (OSTI)

    S. KELLER

    2004-11-03

    This work provides a site-scale transport model for calculating radionuclide transport in the saturated zone (SZ) at Yucca Mountain, for use in the abstractions model in support of ''Total System Performance Assessment for License Application'' (TSPA-LA). The purpose of this model report is to provide documentation for the components of the site-scale SZ transport model in accordance with administrative procedure AP-SIII.10Q, Models. The initial documentation of this model report was conducted under the ''Technical Work Plan For: Saturated Zone Flow and Transport Modeling and Testing'' (BSC 2003 [DIRS 163965]). The model report has been revised in accordance with the ''Technical Work Plan For: Natural System--Saturated Zone Analysis and Model Report Integration'', Section 2.1.1.4 (BSC 2004 [DIRS 171421]) to incorporate Regulatory Integration Team comments. All activities listed in the technical work plan that are appropriate to the transport model are documented in this report and are described in Section 2.1.1.4 (BSC 2004 [DIRS 171421]). This report documents: (1) the advection-dispersion transport model including matrix diffusion (Sections 6.3 and 6.4); (2) a description and validation of the transport model (Sections 6.3 and 7); (3) the numerical methods for simulating radionuclide transport (Section 6.4); (4) the parameters (sorption coefficient, Kd ) and their uncertainty distributions used for modeling radionuclide sorption (Appendices A and C); (5) the parameters used for modeling colloid-facilitated radionuclide transport (Table 4-1, Section 6.4.2.6, and Appendix B); and (6) alternative conceptual models and their dispositions (Section 6.6). The intended use of this model is to simulate transport in saturated fractured porous rock (double porosity) and alluvium. The particle-tracking method of simulating radionuclide transport is incorporated in the finite-volume heat and mass transfer numerical analysis (FEHM) computer code, (FEHM V2.20, STN: 10086-2.20-00) (LANL 2003 [DIRS 161725]) and is described in Section 6.4 of this report. FEHM is a three-dimensional (3-D), finite-volume, finite-element, heat and mass flow-and-transport code. This report documents the features and capabilities of the site-scale transport model for calculating radionuclide transport in the SZ at Yucca Mountain in support of the TSPA-LA. Correlative flow-model calculations using FEHM are carried out and documented in the model report ''Saturated Zone Site-Scale Flow Model'' (BSC 2004 [DIRS 170037]). The velocity fields are calculated by the flow model independent of the transport processes and supplied as a part of the output package from the flow model, which is then used as inputs to the transport model. Several SZ analysis model reports provide information and data needed as feed-ins for this report, and this report in turn provides technical product outputs that feed into other SZ reports. The details of inputs to the site-scale transport model are provided in Section 4.

  18. Adams County, Washington ASHRAE 169-2006 Climate Zone | Open...

    Open Energy Info (EERE)

    ASHRAE 169-2006 Climate Zone Jump to: navigation, search County Climate Zone Place Adams County, Washington ASHRAE Standard ASHRAE 169-2006 Climate Zone Number Climate Zone...

  19. Estimation of Fracture Porosity in an Unsaturated Fractured Welded Tuff Using Gas Tracer Testing

    SciTech Connect (OSTI)

    B.M. Freifeild

    2001-10-18

    Kinematic fracture porosity is an important hydrologic transport parameter for predicting the potential of rapid contaminant migration through fractured rock. The transport velocity of a solute moving within a fracture network is inversely related to the fracture porosity. Since fracture porosity is often one or two orders of magnitude smaller than matrix porosity, and fracture permeability is often orders of magnitude greater than matrix permeability, solutes may travel significantly faster in the fracture network than in the surrounding matrix. This dissertation introduces a new methodology for conducting gas tracer tests using a field portable mass spectrometer along with analytical tools for estimating fracture porosity using the measured tracer concentration breakthrough curves. Field experiments were conducted at Yucca Mountain, Nevada, consisting of air-permeability transient testing and gas-tracer-transport tests. The experiments were conducted from boreholes drilled within an underground tunnel as part of an investigation of rock mass hydrological behavior. Air-permeability pressure transients, recorded during constant mass flux injections, have been analyzed using a numerical inversion procedure to identify fracture permeability and porosity. Dipole gas tracer tests have also been conducted from the same boreholes used for air-permeability testing. Mass breakthrough data has been analyzed using a random walk particle-tracking model, with a dispersivity that is a function of the advective velocity. The estimated fracture porosity using the tracer test and air-injection test data ranges from .001 to .015. These values are an order of magnitude greater than the values estimated by others using hydraulically estimated fracture apertures. The estimates of porosity made using air-permeability test data are shown to be highly sensitive to formation heterogeneity. Uncertainty analyses performed on the gas tracer test results show high confidence in the parameter estimates made.

  20. Fracture porosimeter--a new tool for determining fracture conductivity under downhole stress

    SciTech Connect (OSTI)

    Wedorff, C.L.

    1982-09-01

    This paper describes a new, fast, simplified procedure for determining fracture conductivity at downhole stresses. The embedment and crushing of proppant between rock samples from a specific formation are measured at closure stresses. The conductivities of fractures propped with various proppants can be determined rather quickly. As a result, the procedure can supply information useful in determining optimum fracture treatment for a specific well. In the new procedure, samples of formation and proppants are placed in an appropriate confinement chamber. Closure stresses are applied and fracture conductivity can be calculated. A proppant data base obtained using a modified Cooke conductivity test unit includes permeabilities, porosities and fracture widths measured over a range of closure stresses. These properties are dependent upon the type and amount of proppant tested and the stress applied. The paper includes examples of permeability and surface areas of conventional proppants. Fracture conductivity determinations, made with a variety of formations and proppants, indicate how this procedure can be useful when making decisions concerning fracture treatment design. An improvement in equipment design is also presented. The use of a Hoek triaxial cell as a fracture porosimeter allows the application of both closure and confining stresses, thus more closely simulating downhole conditions.

  1. Fault and joint geometry at Raft River geothermal area, Idaho...

    Open Energy Info (EERE)

    may be useful for locating the surface traces of faults in the reservoir. Authors Guth, L. R.; Bruhn, R. L.; Beck and S. L. Published DOE Information Bridge, 711981 DOI...

  2. INVESTIGATION OF HOLOCENE FAULTING PROPOSED C-746-U LANDFILL EXPANSION

    SciTech Connect (OSTI)

    Lettis, William

    2006-07-01

    This report presents the findings of a fault hazard investigation for the C-746-U landfill's proposed expansion located at the Department of Energy's (DOE) Paducah Gaseous Diffusion Plant (PGDP), in Paducah, Kentucky. The planned expansion is located directly north of the present-day C-746-U landfill. Previous geophysical studies within the PGDP site vicinity interpret possible northeast-striking faults beneath the proposed landfill expansion, although prior to this investigation the existence, locations, and ages of these inferred faults have not been confirmed through independent subsurface exploration. The purpose of this investigation is to assess whether or not Holocene-active fault displacement is present beneath the footprint of the proposed landfill expansion.

  3. High-Resolution Aeromagnetic Survey to Image Shallow Faults,...

    Open Energy Info (EERE)

    to Image Shallow Faults, Dixie Valley Geothermal Field, Nevada Abstract NA Author V. J. S. Grauch Published U.S. Geological Survey, 2002 Report Number 02-384 DOI Not Provided...

  4. Fault Tree Reliability Analysis and Design-for-reliability

    Energy Science and Technology Software Center (OSTI)

    1998-05-05

    WinR provides a fault tree analysis capability for performing systems reliability and design-for-reliability analyses. The package includes capabilities for sensitivity and uncertainity analysis, field failure data analysis, and optimization.

  5. Recent earthquake sequences at Coso: Evidence for conjugate faulting...

    Open Energy Info (EERE)

    earthquake sequences at Coso: Evidence for conjugate faulting and stress loading near a geothermal field Jump to: navigation, search OpenEI Reference LibraryAdd to library Journal...

  6. STRESS AND FAULTING IN THE COSO GEOTHERMAL FIELD: UPDATE AND...

    Open Energy Info (EERE)

    STRESS AND FAULTING IN THE COSO GEOTHERMAL FIELD: UPDATE AND RECENT RESULTS FROM THE EAST FLANK AND COSO WASH Jump to: navigation, search OpenEI Reference LibraryAdd to library...

  7. Coupled hydro-mechanical processes and fault reactivation induced...

    Office of Scientific and Technical Information (OSTI)

    Coupled hydro-mechanical processes and fault reactivation induced by Co2 Injection in a three-layer storage formation Citation Details In-Document Search This content will become ...

  8. Exploiting data representation for fault tolerance

    SciTech Connect (OSTI)

    Hoemmen, Mark Frederick; Elliott, J.; Mueller, F.

    2015-01-06

    Incorrect computer hardware behavior may corrupt intermediate computations in numerical algorithms, possibly resulting in incorrect answers. Prior work models misbehaving hardware by randomly flipping bits in memory. We start by accepting this premise, and present an analytic model for the error introduced by a bit flip in an IEEE 754 floating-point number. We then relate this finding to the linear algebra concepts of normalization and matrix equilibration. In particular, we present a case study illustrating that normalizing both vector inputs of a dot product minimizes the probability of a single bit flip causing a large error in the dot product's result. Moreover, the absolute error is either less than one or very large, which allows detection of large errors. Then, we apply this to the GMRES iterative solver. We count all possible errors that can be introduced through faults in arithmetic in the computationally intensive orthogonalization phase of GMRES, and show that when the matrix is equilibrated, the absolute error is bounded above by one.

  9. Exploiting data representation for fault tolerance

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Hoemmen, Mark Frederick; Elliott, J.; Sandia National Lab.; Mueller, F.

    2015-01-06

    Incorrect computer hardware behavior may corrupt intermediate computations in numerical algorithms, possibly resulting in incorrect answers. Prior work models misbehaving hardware by randomly flipping bits in memory. We start by accepting this premise, and present an analytic model for the error introduced by a bit flip in an IEEE 754 floating-point number. We then relate this finding to the linear algebra concepts of normalization and matrix equilibration. In particular, we present a case study illustrating that normalizing both vector inputs of a dot product minimizes the probability of a single bit flip causing a large error in the dot product'smore » result. Moreover, the absolute error is either less than one or very large, which allows detection of large errors. Then, we apply this to the GMRES iterative solver. We count all possible errors that can be introduced through faults in arithmetic in the computationally intensive orthogonalization phase of GMRES, and show that when the matrix is equilibrated, the absolute error is bounded above by one.« less

  10. The influence of coarse aggregate size and volume on the fracture behavior and brittleness of self-compacting concrete

    SciTech Connect (OSTI)

    Beygi, Morteza H.A.; Kazemi, Mohammad Taghi; Nikbin, Iman M.; Vaseghi Amiri, Javad; Rabbanifar, Saeed; Rahmani, Ebrahim

    2014-12-15

    This paper presents the results of an experimental investigation on fracture characteristics and brittleness of self-compacting concrete (SCC), involving the tests of 185 three point bending beams with different coarse aggregate size and content. Generally, the parameters were analyzed by the work of fracture method (WFM) and the size effect method (SEM). The results showed that with increase of size and content of coarse aggregate, (a) the fracture energy increases which is due to the change in fractal dimensions, (b) behavior of SCC beams approaches strength criterion, (c) characteristic length, which is deemed as an index of brittleness, increases linearly. It was found with decrease of w/c ratio that fracture energy increases which may be explained by the improvement in structure of aggregate-paste transition zone. Also, the results showed that there is a correlation between the fracture energy measured by WFM (G{sub F}) and the value measured through SEM (G{sub f}) (G{sub F} = 3.11G{sub f})

  11. Fault-induced delayed voltage recovery in a long inhomogeneous

    Office of Scientific and Technical Information (OSTI)

    power-distribution feeder (Journal Article) | SciTech Connect Journal Article: Fault-induced delayed voltage recovery in a long inhomogeneous power-distribution feeder Citation Details In-Document Search Title: Fault-induced delayed voltage recovery in a long inhomogeneous power-distribution feeder Authors: Stolbova, Irina ; Backhaus, Scott ; Chertkov, Michael Publication Date: 2015-02-23 OSTI Identifier: 1180264 Grant/Contract Number: AC52-06NA25396 Type: Publisher's Accepted Manuscript

  12. On the effect of x-ray irradiation on the deformation and fracture behavior of human cortical bone

    SciTech Connect (OSTI)

    Barth, Holly D.; Launey, Maximilien E.; McDowell, Alastair A.; Ager III, Joel W.; Ritchie, Robert O.

    2010-01-10

    In situ mechanical testing coupled with imaging using high-energy synchrotron x-ray diffraction or tomography imaging is gaining in popularity as a technique to investigate micrometer and even sub-micrometer deformation and fracture mechanisms in mineralized tissues, such as bone and teeth. However, the role of the irradiation in affecting the nature and properties of the tissue is not always taken into account. Accordingly, we examine here the effect of x-ray synchrotron-source irradiation on the mechanistic aspects of deformation and fracture in human cortical bone. Specifically, the strength, ductility and fracture resistance (both work-of-fracture and resistance-curve fracture toughness) of human femoral bone in the transverse (breaking) orientation were evaluated following exposures to 0.05, 70, 210 and 630 kGy irradiation. Our results show that the radiation typically used in tomography imaging can have a major and deleterious impact on the strength, post-yield behavior and fracture toughness of cortical bone, with the severity of the effect progressively increasing with higher doses of radiation. Plasticity was essentially suppressed after as little as 70 kGy of radiation; the fracture toughness was decreased by a factor of five after 210 kGy of radiation. Mechanistically, the irradiation was found to alter the salient toughening mechanisms, manifest by the progressive elimination of the bone's capacity for plastic deformation which restricts the intrinsic toughening from the formation 'plastic zones' around crack-like defects. Deep-ultraviolet Raman spectroscopy indicated that this behavior could be related to degradation in the collagen integrity.

  13. Microcomputer applications of, and modifications to, the modular fault trees

    SciTech Connect (OSTI)

    Zimmerman, T.L.; Graves, N.L.; Payne, A.C. Jr.; Whitehead, D.W.

    1994-10-01

    The LaSalle Probabilistic Risk Assessment was the first major application of the modular logic fault trees after the IREP program. In the process of performing the analysis, many errors were discovered in the fault tree modules that led to difficulties in combining the modules to form the final system fault trees. These errors are corrected in the revised modules listed in this report. In addition, the application of the modules in terms of editing them and forming them into the system fault trees was inefficient. Originally, the editing had to be done line by line and no error checking was performed by the computer. This led to many typos and other logic errors in the construction of the modular fault tree files. Two programs were written to help alleviate this problem: (1) MODEDIT - This program allows an operator to retrieve a file for editing, edit the file for the plant specific application, perform some general error checking while the file is being modified, and store the file for later use, and (2) INDEX - This program checks that the modules that are supposed to form one fault tree all link up appropriately before the files are,loaded onto the mainframe computer. Lastly, the modules were not designed for relay type logic common in BWR designs but for solid state type logic. Some additional modules were defined for modeling relay logic, and an explanation and example of their use are included in this report.

  14. AltaRock Energy Announces Successful Multiple-Zone Stimulation...

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    cold water at moderate pressure to enhance the permeability of existing fractures. ... to the water and partially plugged the first set of stimulated fractures at the wellbore. ...

  15. Deep Vadose Zone | Department of Energy

    Energy Savers [EERE]

    Deep Vadose Zone Deep Vadose Zone The Mission of the Deep Vadose Zone Applied Field Research Initiative is to protect water resources across the DOE complex over the long-term by developing effective solutions to solve DOE's most challenging deep vadose zone characterization, remediation, monitoring, and prediction challenges. PDF icon Deep Vadose Zone More Documents & Publications Remediation of Mercury and Industrial Contaminants Advanced Simulation Capability of Environmental Management

  16. Fracture characteristics and their relationships to producing...

    Open Energy Info (EERE)

    characteristics and their relationships to producing zones in deep wells, Raft River geothermal area Jump to: navigation, search OpenEI Reference LibraryAdd to library Book:...

  17. Thermochemically Driven Gas-Dynamic Fracturing (TDGF)

    SciTech Connect (OSTI)

    Michael Goodwin

    2008-12-31

    This report concerns efforts to increase oil well productivity and efficiency via a method of heating the oil-bearing rock of the well, a technique known as Thermochemical Gas-Dynamic Fracturing (TGDF). The technique uses either a chemical reaction or a combustion event to raise the temperature of the rock of the well, thereby increasing oil velocity, and oil pumping rate. Such technology has shown promise for future application to both older wellheads and also new sites. The need for such technologies in the oil extraction field, along with the merits of the TGDF technology is examined in Chapter 1. The theoretical basis underpinning applications of TGDF is explained in Chapter 2. It is shown that productivity of depleted well can be increased by one order of magnitude after heating a reservoir region of radius 15-20 m around the well by 100 degrees 1-2 times per year. Two variants of thermal stimulation are considered: uniform heating and optimal temperature distribution in the formation region around the perforation zone. It is demonstrated that the well productivity attained by using equal amounts of thermal energy is higher by a factor of 3 to 4 in the case of optimal temperature distribution as compared to uniform distribution. Following this theoretical basis, two practical approaches to applying TDGF are considered. Chapter 3 looks at the use of chemical intiators to raise the rock temperature in the well via an exothermic chemical reaction. The requirements for such a delivery device are discussed, and several novel fuel-oxidizing mixtures (FOM) are investigated in conditions simulating those at oil-extracting depths. Such FOM mixtures, particularly ones containing nitric acid and a chemical initiator, are shown to dramatically increase the temperature of the oil-bearing rock, and thus the productivity of the well. Such tests are substantiated by preliminary fieldwork in Russian oil fields. A second, more cost effective approach to TGDF is considered in Chapter 4: use of diesel-fuel to raise the rock temperature by a combustion process in the well. The requirements for such a Gas-Vapor Generator are laid out, and the development of a prototype machine is explained. This is backed up with laboratory experiments showing that the fuel-water mixture used does significantly increase the viscosity of the oil samples. The prototype Gas-Vapor Generator is shown to be able to operate at temperatures of 240 C and pressures of 200 atm. Unfortunately, geopolitical and economic factors outside of our control led to the cancellation of the project before the field testing phase of the generator could be commenced. Nevertheless, it is to be hoped that this report demonstrates both the feasibility and desirability of the Gas-Vapor Generator approach to the application of TDGF technology in both existing and new wells, and provides a foundation for further research in the future.

  18. IPIRG programs - advances in pipe fracture technology

    SciTech Connect (OSTI)

    Wilkowski, G.; Olson, R.; Scott, P.

    1997-04-01

    This paper presents an overview of the advances made in fracture control technology as a result of the research performed in the International Piping Integrity Research Group (IPIRG) program. The findings from numerous experiments and supporting analyses conducted to investigate the behavior of circumferentially flawed piping and pipe systems subjected to high-rate loading typical of seismic events are summarized. Topics to be discussed include; (1) Seismic loading effects on material properties, (2) Piping system behavior under seismic loads, (3) Advances in elbow fracture evaluations, and (4) {open_quotes}Real{close_quotes} piping system response. The presentation for each topic will be illustrated with data and analytical results. In each case, the state-of-the-art in fracture mechanics prior to the first IPIRG program will be contrasted with the state-of-the-art at the completion of the IPIRG-2 program.

  19. New proppant for deep hydraulic fracturing

    SciTech Connect (OSTI)

    Underdown, D.R.; Das, K.

    1982-01-01

    Much work has been done in the development and evaluation of various materials for use as proppants for hydraulic fracturing. Sand is most often used as a frac proppant in shallow wells. Deep wells having high closure stresses require a proppant such as sintered bauxite which will not crush under such adverse conditions. Proppants such as ceramic and zirconium oxide beads and resin coated sand have been developed for deep hydraulic fracturing; however, use of these materials has been limited. A new frac proppant has been developed which exhibits the properties necessary for use in deep hydraulic fracturing. This frac proppant is produced by precuring a specially modified phenol-formaldehyde resin onto sand. The new frac proppant maintains conductivity and resists crushing, similar to that of sintered bauxite at high closure stress. 11 references.

  20. Origin of reservoir fractures in Little Knife field, North Dakota

    SciTech Connect (OSTI)

    Narr, W.; Burrus, R.C.

    1984-09-01

    Thin, vertical, planar fractures observed in the Mission Canyon Formation, at the Little Knife field, are naturally occurring and appear to be extension fractures. The predominant east-west trend of the fractures, measured in oriented core from six wells, parallels the contemporary maximum horizontal compressive stress in the Williston basin. The fractures occur only in carbonate units, but within the carbonates their occurrence is not lithology dependent. Fracture density measured in the cores of the reservoir carbonates averages 1 ft (.3 m) of fracture per 2.3 ft (.7 m) of core. The formation and mineralization of reservoir fractures were the most recent diagenetic events in the Mission Canyon Formation at Little Knife. Study of aqueous and hydrocarbon fluid inclusions associated with the fractures reveals: (1) fractures formed after the strata were buried to at least their present depth of 9,800 ft (2,987 m), which indicates their age is post-Mesozoic; (2) the pore-fluid pressure gradient was normal hydrostatic immediately after, if not during, fracture system development; (3) formation-water salinity has remained fairly constant since fracture initiation; (4) migration of hydrocarbons into the reservoir probably preceded fracture genesis; and (5) methane concentration may have decreased since fracture initiation.

  1. Partially penetrating fractures: Pressure transient analysis of an infinite conductivity fracture

    SciTech Connect (OSTI)

    Rodriguez, F.; Cinco-Ley, H.; Horne, R.N.

    1984-04-01

    The effect of the partial penetration of an infinite conductivity fracture on the transient pressure behavior of a vertically fractured well is investigated. Analysis of results shows that the pressure behavior of a well intersected by a partially-penetrating infinite conductivity vertical fracture can be divided into three flow periods: 1) the early time flow period which is characterized by a formation linear flow as in the case of a fully-penetrating infinite-conductivity vertical fracture, 2) the infinite-acting flow period and 3) the pseudoradial flow period which develops after the effects of the vertical boundaries of the reservoir are felt in the pressure behavior of the well. A log-log graph of log(h /SUB f/ /h)p /SUB wD/ versus log t /SUB Dxf/ shows a slope of one half during the early time flow period of a well with an infinite-conductivity partially penetrating fracture. The time for the end of the early time flow period is directly related to the square of the dimensionless height of the fracture, h /SUB fD/, which is defined as the ratio between the height of the fracture and its half length.

  2. Property:Buildings/ModelClimateZone | Open Energy Information

    Open Energy Info (EERE)

    Climate Zone 7A Climate Zone 7B Climate Zone 8A Climate Zone 8B Pages using the property "BuildingsModelClimateZone" Showing 12 pages using this property. G General Merchandise...

  3. Compartmentalization analysis using discrete fracture network models

    SciTech Connect (OSTI)

    La Pointe, P.R.; Eiben, T.; Dershowitz, W.; Wadleigh, E.

    1997-08-01

    This paper illustrates how Discrete Fracture Network (DFN) technology can serve as a basis for the calculation of reservoir engineering parameters for the development of fractured reservoirs. It describes the development of quantitative techniques for defining the geometry and volume of structurally controlled compartments. These techniques are based on a combination of stochastic geometry, computational geometry, and graph the theory. The parameters addressed are compartment size, matrix block size and tributary drainage volume. The concept of DFN models is explained and methodologies to compute these parameters are demonstrated.

  4. Fracture Toughness Prediction for MWCNT Reinforced Ceramics

    SciTech Connect (OSTI)

    Henager, Charles H.; Nguyen, Ba Nghiep

    2013-09-01

    This report describes the development of a micromechanics model to predict fracture toughness of multiwall carbon nanotube (MWCNT) reinforced ceramic composites to guide future experimental work for this project. The modeling work described in this report includes (i) prediction of elastic properties, (ii) development of a mechanistic damage model accounting for matrix cracking to predict the composite nonlinear stress/strain response to tensile loading to failure, and (iii) application of this damage model in a modified boundary layer (MBL) analysis using ABAQUS to predict fracture toughness and crack resistance behavior (R-curves) for ceramic materials containing MWCNTs at various volume fractions.

  5. Overlap zoned electrically heated particulate filter

    DOE Patents [OSTI]

    Gonze, Eugene V [Pinckney, MI; Chapman, Mark R [Brighton, MI

    2011-07-19

    A system includes a particulate matter (PM) filter that includes an upstream end for receiving exhaust gas and a downstream end. A zoned heater is arranged spaced from the upstream end and comprises N zones, where N is an integer greater than one, wherein each of the N zones comprises M sub-zones, where M is an integer greater than or equal to one, and wherein the N zones and the M sub-zones are arranged in P layers, where P is an integer greater than one. A control module selectively activates at least a selected one of the N zones to initiate regeneration in downstream portions of the PM filter from the one of the N zones and deactivates non-selected ones of the N zones.

  6. Fracture Evolution Following a Hydraulic Stimulation within an EGS Reservoir

    Broader source: Energy.gov [DOE]

    DOE Geothermal Peer Review 2010 - Presentation. This project will provide the first ever formal evaluation of fracture and fracture flow evolution in an EGS reservoir following a hydraulic stimulation.

  7. Simulated evolution of fractures and fracture networks subject to thermal cooling: A coupled discrete element and heat conduction model

    SciTech Connect (OSTI)

    Huang, Hai; Plummer, Mitchell; Podgorney, Robert

    2013-02-01

    Advancement of EGS requires improved prediction of fracture development and growth during reservoir stimulation and long-term operation. This, in turn, requires better understanding of the dynamics of the strongly coupled thermo-hydro-mechanical (THM) processes within fractured rocks. We have developed a physically based rock deformation and fracture propagation simulator by using a quasi-static discrete element model (DEM) to model mechanical rock deformation and fracture propagation induced by thermal stress and fluid pressure changes. We also developed a network model to simulate fluid flow and heat transport in both fractures and porous rock. In this paper, we describe results of simulations in which the DEM model and network flow & heat transport model are coupled together to provide realistic simulation of the changes of apertures and permeability of fractures and fracture networks induced by thermal cooling and fluid pressure changes within fractures. Various processes, such as Stokes flow in low velocity pores, convection-dominated heat transport in fractures, heat exchange between fluid-filled fractures and solid rock, heat conduction through low-permeability matrices and associated mechanical deformations are all incorporated into the coupled model. The effects of confining stresses, developing thermal stress and injection pressure on the permeability evolution of fracture and fracture networks are systematically investigated. Results are summarized in terms of implications for the development and evolution of fracture distribution during hydrofracturing and thermal stimulation for EGS.

  8. MULTI-PHASE FRACTURE-MATRIX INTERACTIONS UNDER STRESS CHANGES

    SciTech Connect (OSTI)

    A.S. Grader; D. Elsworth; P.M. Halleck; F. Alvarado; A. Alajmi; Z. Karpyn; N. Mohammed; S. Al-Enezi

    2005-06-15

    The main objectives of this project are to quantify the changes in fracture porosity and multiphase transport properties as a function of confining stress. These changes will be integrated into conceptual and numerical models that will improve our ability to predict and optimize fluid transport in fractured system. This report details our progress on: (a) developing the direct experimental measurements of fracture aperture and topology and fluid occupancy using high-resolution x-ray micro-tomography, (b) quantifying the effect of confining stress on the distribution of fracture aperture, and (c) characterization of shear fractures and their impact on multi-phase flow. The three-dimensional surface that describes the large-scale structure of the fracture in the porous medium can be determined using x-ray micro-tomography with significant accuracy. Several fractures have been scanned and the fracture aperture maps have been extracted. The success of the mapping of fracture aperture was followed by measuring the occupancy of the fracture by two immiscible phases, water and decane, and water and kerosene. The distribution of fracture aperture depends on the effective confining stress on the nature of the rock and the type and distribution of the asperities that keep the fracture open. Fracture apertures at different confining stresses were obtained by micro-tomography covering a range of about two thousand psig. Initial analysis of the data shows a significant aperture closure with increase in effective confining stress. Visual descriptions of the process are shown in the report while detailed analysis of the behavior of the distribution of fracture aperture is in progress. Both extensional and shear fractures are being considered. The initial multi-phase flow tests were done in extensional fractures. Several rock samples with induced shear fracture are being studied, and some of the new results are presented in this report. These samples are being scanned in order to quantify the distribution of apertures and the nature of the asperities. Low resolution images of fluids in a sample with a shear fracture were performed and they provide the confidence that flow patterns and saturations could be determined in the future. A series of water imbibition tests were conducted in which water was injected into a fracture and its migration into the matrix was monitored with CT and DR x-ray techniques. The objective is to understand the impact of the fracture, its topology and occupancy on the nature of mass transfer between the matrix and the fracture. Counter-current imbibition next to the fracture was observed and quantified, including the influence of formation layering.

  9. Predicting fracture in micron-scale polycrystalline silicon MEMS...

    Office of Scientific and Technical Information (OSTI)

    Designing reliable MEMS structures presents numerous challenges. Polycrystalline silicon fractures in a brittle manner with considerable variability in measured strength. ...

  10. Modification of fracture surfaces by dissolution. Part II (Conference...

    Office of Scientific and Technical Information (OSTI)

    Subject: 58 GEOSCIENCES; 15 GEOTHERMAL ENERGY; QUARTZ; DISSOLUTION; QUARTZITES; ROCK-FLUID INTERACTIONS; AQUEOUS SOLUTIONS; EXPERIMENTAL DATA; FRACTURES; SODIUM CARBONATES; ...

  11. Use of Tracers to Characterize Fractures in Engineered Geothermal...

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    fabricate and test a downhole instrument for measuring fracture flow following a hydraulic stimulation experiment. reservoirrosetracerscharacterizefractures.pdf More...

  12. 1112323-danimer-abstract-hydraulic-fractures | netl.doe.gov

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    fracturing treatments including: less hydraulic horsepower requirements, decreased footprint, simpler execution, lower water utilization, use of non-damaging biodegradable...

  13. Acid fracturing of carbonate gas reservoirs in Sichuan

    SciTech Connect (OSTI)

    Meng, M.

    1982-01-01

    The paper presents the geological characteristics of Sinian-furassic carbonate gas reservoirs in the Sichuan basin, China. Based on these characteristics, a mechanism of acid fracturing is proposed for such reservoirs. Included are the results of a research in acid fracturing fluids and field operation conditions for matrix acidizing and acid fracturing in Sichuan. The acid fracturing method is shown to be an effective stimulation technique for the carbonate strata in this area.

  14. Experimental and Analytical Research on Fracture Processes in ROck

    SciTech Connect (OSTI)

    Herbert H.. Einstein; Jay Miller; Bruno Silva

    2009-02-27

    Experimental studies on fracture propagation and coalescence were conducted which together with previous tests by this group on gypsum and marble, provide information on fracturing. Specifically, different fracture geometries wsere tested, which together with the different material properties will provide the basis for analytical/numerical modeling. INitial steps on the models were made as were initial investigations on the effect of pressurized water on fracture coalescence.

  15. Increasing Production from Low-Permeability Gas Reservoirs by Optimizing Zone Isolation for Successful Stimulation Treatments

    SciTech Connect (OSTI)

    Fred Sabins

    2005-03-31

    Maximizing production from wells drilled in low-permeability reservoirs, such as the Barnett Shale, is determined by cementing, stimulation, and production techniques employed. Studies show that cementing can be effective in terms of improving fracture effectiveness by 'focusing' the frac in the desired zone and improving penetration. Additionally, a method is presented for determining the required properties of the set cement at various places in the well, with the surprising result that uphole cement properties in wells destined for multiple-zone fracturing is more critical than those applied to downhole zones. Stimulation studies show that measuring pressure profiles and response during Pre-Frac Injection Test procedures prior to the frac job are critical in determining if a frac is indicated at all, as well as the type and size of the frac job. This result is contrary to current industry practice, in which frac jobs are designed well before the execution, and carried out as designed on location. Finally, studies show that most wells in the Barnett Shale are production limited by liquid invasion into the wellbore, and determinants are presented for when rod or downhole pumps are indicated.

  16. Nonlinear dynamics in flow through unsaturated fractured-porous media: Status and perspectives

    SciTech Connect (OSTI)

    Faybishenko, Boris

    2002-11-27

    The need has long been recognized to improve predictions of flow and transport in partially saturated heterogeneous soils and fractured rock of the vadose zone for many practical applications, such as remediation of contaminated sites, nuclear waste disposal in geological formations, and climate predictions. Until recently, flow and transport processes in heterogeneous subsurface media with oscillating irregularities were assumed to be random and were not analyzed using methods of nonlinear dynamics. The goals of this paper are to review the theoretical concepts, present the results, and provide perspectives on investigations of flow and transport in unsaturated heterogeneous soils and fractured rock, using the methods of nonlinear dynamics and deterministic chaos. The results of laboratory and field investigations indicate that the nonlinear dynamics of flow and transport processes in unsaturated soils and fractured rocks arise from the dynamic feedback and competition between various nonlinear physical processes along with complex geometry of flow paths. Although direct measurements of variables characterizing the individual flow processes are not technically feasible, their cumulative effect can be characterized by analyzing time series data using the models and methods of nonlinear dynamics and chaos. Identifying flow through soil or rock as a nonlinear dynamical system is important for developing appropriate short- and long-time predictive models, evaluating prediction uncertainty, assessing the spatial distribution of flow characteristics from time series data, and improving chemical transport simulations. Inferring the nature of flow processes through the methods of nonlinear dynamics could become widely used in different areas of the earth sciences.

  17. Accident Fault Trees for Defense Waste Processing Facility

    SciTech Connect (OSTI)

    Sarrack, A.G.

    1999-06-22

    The purpose of this report is to document fault tree analyses which have been completed for the Defense Waste Processing Facility (DWPF) safety analysis. Logic models for equipment failures and human error combinations that could lead to flammable gas explosions in various process tanks, or failure of critical support systems were developed for internal initiating events and for earthquakes. These fault trees provide frequency estimates for support systems failures and accidents that could lead to radioactive and hazardous chemical releases both on-site and off-site. Top event frequency results from these fault trees will be used in further APET analyses to calculate accident risk associated with DWPF facility operations. This report lists and explains important underlying assumptions, provides references for failure data sources, and briefly describes the fault tree method used. Specific commitments from DWPF to provide new procedural/administrative controls or system design changes are listed in the ''Facility Commitments'' section. The purpose of the ''Assumptions'' section is to clarify the basis for fault tree modeling, and is not necessarily a list of items required to be protected by Technical Safety Requirements (TSRs).

  18. Field Guide for Testing Existing Photovoltaic Systems for Ground Faults and Installing Equipment to Mitigate Fire Hazards

    SciTech Connect (OSTI)

    Brooks, William; Basso, Thomas; Coddington, Michael

    2015-10-01

    Ground faults and arc faults are the two most common reasons for fires in photovoltaic (PV) arrays and methods exist that can mitigate the hazards. This report provides field procedures for testing PV arrays for ground faults, and for implementing high resolution ground fault and arc fault detectors in existing and new PV system designs.

  19. Method for describing fractures in subterranean earth formations

    DOE Patents [OSTI]

    Shuck, Lowell Z.

    1977-01-01

    The configuration and directional orientation of natural or induced fractures in subterranean earth formations are described by introducing a liquid explosive into the fracture, detonating the explosive, and then monitoring the resulting acoustic emissions with strategically placed acoustic sensors as the explosion propagates through the fracture at a known rate.

  20. Aligned vertical fractures, HTI reservoir symmetry, and Thomsenseismic anisotropy parameters

    SciTech Connect (OSTI)

    Berryman, James G.

    2007-06-27

    The Sayers and Kachanov (1991) crack-influence parametersare shown to be directly related to Thomsen (1986) weak-anisotropyseismic parameters for fractured reservoirs when the crack density issmall enough. These results are then applied to seismic wave propagationin reservoirs having HTI symmetry due to aligned vertical fractures. Theapproach suggests a method of inverting for fracture density from wavespeed data.

  1. San Juan Fracture Characterization Project: Status and current results

    SciTech Connect (OSTI)

    Majer, E.L.; Daley, T.M.; Myer, L.R.; Nihei, K.; Queen, J.; Sinton, J.; Murphy, J.; Fortuna, M.; Lynn, H.B.; Imhoff, M.A.; Wilson, R.

    2001-02-26

    The overall objectives of this report are to extend current state-of-the-art 3-D imaging to extract the optimal information for fracture quantification and to develop next generation capability in fracture imaging for true 3-D imaging of the static and dynamic fracture properties.

  2. Transient Non Lin Deformation in Fractured Rock

    Energy Science and Technology Software Center (OSTI)

    1998-10-14

    MATLOC is a nonlinear, transient, two-dimensional (planer and axisymmetric), thermal stress, finite-element code designed to determine the deformation within a fractured rock mass. The mass is modeled as a nonlinear anistropic elastic material which can exhibit stress-dependent bi-linear locking behavior.

  3. Atom-to-continuum methods for gaining a fundamental understanding of fracture.

    SciTech Connect (OSTI)

    McDowell, David Lynn; Reedy, Earl David, Jr.; Templeton, Jeremy Alan; Jones, Reese E.; Moody, Neville Reid; Zimmerman, Jonathan A.; Belytschko, Ted.; Zhou, Xiao Wang; Lloyd, Jeffrey T.; Oswald, Jay; Delph, Terry J.; Kimmer, Christopher J.

    2011-08-01

    This report describes an Engineering Sciences Research Foundation (ESRF) project to characterize and understand fracture processes via molecular dynamics modeling and atom-to-continuum methods. Under this aegis we developed new theory and a number of novel techniques to describe the fracture process at the atomic scale. These developments ranged from a material-frame connection between molecular dynamics and continuum mechanics to an atomic level J integral. Each of the developments build upon each other and culminated in a cohesive zone model derived from atomic information and verified at the continuum scale. This report describes an Engineering Sciences Research Foundation (ESRF) project to characterize and understand fracture processes via molecular dynamics modeling and atom-to-continuum methods. The effort is predicated on the idea that processes and information at the atomic level are missing in engineering scale simulations of fracture, and, moreover, are necessary for these simulations to be predictive. In this project we developed considerable new theory and a number of novel techniques in order to describe the fracture process at the atomic scale. Chapter 2 gives a detailed account of the material-frame connection between molecular dynamics and continuum mechanics we constructed in order to best use atomic information from solid systems. With this framework, in Chapter 3, we were able to make a direct and elegant extension of the classical J down to simulations on the scale of nanometers with a discrete atomic lattice. The technique was applied to cracks and dislocations with equal success and displayed high fidelity with expectations from continuum theory. Then, as a prelude to extension of the atomic J to finite temperatures, we explored the quasi-harmonic models as efficient and accurate surrogates of atomic lattices undergoing thermo-elastic processes (Chapter 4). With this in hand, in Chapter 5 we provide evidence that, by using the appropriate energy potential, the atomic J integral we developed is calculable and accurate at finite/room temperatures. In Chapter 6, we return in part to the fundamental efforts to connect material behavior at the atomic scale to that of the continuum. In this chapter, we devise theory that predicts the onset of instability characteristic of fracture/failure via atomic simulation. In Chapters 7 and 8, we describe the culmination of the project in connecting atomic information to continuum modeling. In these chapters we show that cohesive zone models are: (a) derivable from molecular dynamics in a robust and systematic way, and (b) when used in the more efficient continuum-level finite element technique provide results that are comparable and well-correlated with the behavior at the atomic-scale. Moreover, we show that use of these same cohesive zone elements is feasible at scales very much larger than that of the lattice. Finally, in Chapter 9 we describe our work in developing the efficient non-reflecting boundary conditions necessary to perform transient fracture and shock simulation with molecular dynamics.

  4. Eastern Energy Zones Mapping Tool

    Broader source: Energy.gov [DOE]

    The Eastern Interconnection States’ Planning Council (EISPC) has released the Energy Zones (EZ) Mapping Tool, a free, web-based interactive tool that will help states and other stakeholders in the Eastern Interconnection identify geographic areas suitable for the development of clean energy resources (natural gas, sequestration or utilitization locations for C02 from coal, nuclear, and renewable) which can potentially provide significant amounts of new electric power generation.

  5. TASK 2: QUENCH ZONE SIMULATION

    SciTech Connect (OSTI)

    Fusselman, Steve

    2015-09-30

    Aerojet Rocketdyne (AR) has developed an innovative gasifier concept incorporating advanced technologies in ultra-dense phase dry feed system, rapid mix injector, and advanced component cooling to significantly improve gasifier performance, life, and cost compared to commercially available state-of-the-art systems. A key feature of the AR gasifier design is the transition from the gasifier outlet into the quench zone, where the raw syngas is cooled to ~ 400°C by injection and vaporization of atomized water. Earlier pilot plant testing revealed a propensity for the original gasifier outlet design to accumulate slag in the outlet, leading to erratic syngas flow from the outlet. Subsequent design modifications successfully resolved this issue in the pilot plant gasifier. In order to gain greater insight into the physical phenomena occurring within this zone, AR developed a cold flow simulation apparatus with Coanda Research & Development with a high degree of similitude to hot fire conditions with the pilot scale gasifier design, and capable of accommodating a scaled-down quench zone for a demonstration-scale gasifier. The objective of this task was to validate similitude of the cold flow simulation model by comparison of pilot-scale outlet design performance, and to assess demonstration scale gasifier design feasibility from testing of a scaled-down outlet design. Test results did exhibit a strong correspondence with the two pilot scale outlet designs, indicating credible similitude for the cold flow simulation device. Testing of the scaled-down outlet revealed important considerations in the design and operation of the demonstration scale gasifier, in particular pertaining to the relative momentum between the downcoming raw syngas and the sprayed quench water and associated impacts on flow patterns within the quench zone. This report describes key findings from the test program, including assessment of pilot plant configuration simulations relative to actual results on the pilot plant gasifier and demonstration plant design recommendations, based on cold flow simulation results.

  6. Climate Zone 8B | Open Energy Information

    Open Energy Info (EERE)

    Subtype B. Climate Zone 8B is defined as Subarctic with IP Units 12600 < HDD65F and SI Units 7000 < HDD18C . The following places are categorized as class 8B climate zones:...

  7. Climate Zone 8A | Open Energy Information

    Open Energy Info (EERE)

    A. Climate Zone Number 8A is defined as Subarctic with IP Units 12600 < HDD65F and SI Units 7000 < HDD18C . The following places are categorized as class 8A climate zones:...

  8. Climate Zone 1A | Open Energy Information

    Open Energy Info (EERE)

    A. Climate Zone 1A is defined as Very Hot - Humid with IP Units 9000 < CDD50F and SI Units 5000 < CDD10C . The following places are categorized as class 1A climate zones:...

  9. Climate Zone Number 5 | Open Energy Information

    Open Energy Info (EERE)

    Climate Zone Number 5 Jump to: navigation, search A type of climate defined in the ASHRAE 169-2006 standard. Climate Zone Number 5 is defined as Cool- Humid(5A) with IP Units 5400...

  10. Farmland Security Zone | Open Energy Information

    Open Energy Info (EERE)

    Security Zone Jump to: navigation, search OpenEI Reference LibraryAdd to library Legal Document- OtherOther: Farmland Security ZoneLegal Abstract California Department of...

  11. Pellet Zone Ltd | Open Energy Information

    Open Energy Info (EERE)

    Pellet Zone Ltd Jump to: navigation, search Name: Pellet Zone Ltd Place: England, United Kingdom Zip: NR19 1AE Sector: Biomass Product: UK based biomass pellet trading firm....

  12. THE INFLUENCE OF FOLD AND FRACTURE DEVELOPMENT ON RESERVOIR BEHAVIOR OF THE LISBURNE GROUP OF NORTHERN ALASKA

    SciTech Connect (OSTI)

    Wesley K. Wallace; Catherine L. Hanks; Jerry Jensen; Michael T. Whalen

    2002-01-01

    The Carboniferous Lisburne Group is a major carbonate reservoir unit in northern Alaska. The Lisburne is detachment folded where it is exposed throughout the northeastern Brooks Range, but is relatively undeformed in areas of current production in the subsurface of the North Slope. The objectives of this study are to develop a better understanding of four major aspects of the Lisburne: (1) The geometry and kinematics of detachment folds and their truncation by thrust faults. (2) The influence of folding on fracture patterns. (3) The influence of deformation on fluid flow. (4) Lithostratigraphy and its influence on folding, faulting, fracturing, and reservoir characteristics. The Lisburne in the main axis of the Brooks Range is characteristically deformed into imbricate thrust sheets with asymmetrical hanging wall anticlines and footwall synclines. In contrast, the Lisburne in the northeastern Brooks Range is characterized by symmetrical detachment folds. The focus of our 2000 field studies was at the boundary between these structural styles in the vicinity of Porcupine Lake, in the Arctic National Wildlife Refuge. The northern edge of thrust-truncated folds in Lisburne is marked by a local range front that likely represents an eastward continuation of the central Brooks Range front. This is bounded to the north by a gently dipping panel of Lisburne with local asymmetrical folds. The leading edge of the flat panel is thrust over Permian to Cretaceous rocks in a synclinal depression. These younger rocks overlie symmetrically detachment-folded Lisburne, as is extensively exposed to the north. Six partial sections were measured in the Lisburne of the flat panel and local range front. The Lisburne here is about 700 m thick and is interpreted to consist primarily of the Wachsmuth and Alapah Limestones, with only a thin veneer of Wahoo Limestone. The Wachsmuth (200 m) is gradational between the underlying Missippian Kayak Shale and the overlying Mississippian Alapah, and increases in resistance upward. The Alapah consists of a lower resistant member (100 m) of alternating limestone and chert, a middle recessive member (100 m), and an upper resistant member (260 m) that is similar to Wahoo in the northeastern Brooks Range. The Wahoo is recessive and is thin (30 m) due either to non-deposition or erosion beneath the sub-Permian unconformity. The Lisburne of the area records two major episodes of transgression and shallowing-upward on a carbonate ramp. Thicknesses and facies vary along depositional strike. Asymmetrical folds, mostly truncated by thrust faults, were studied in and south of the local range front. Fold geometry was documented by surveys of four thrust-truncated folds and two folds not visibly cut by thrusts. A portion of the local range front was mapped to document changes in fold geometry along strike in three dimensions. The folds typically display a long, non-folded gently to moderately dipping backlimbs and steep to overturned forelimbs, commonly including parasitic anticline-syncline pairs. Thrusts commonly cut through the anticlinal forelimb or the forward synclinal hinge. These folds probably originated as detachment folds based on their mechanical stratigraphy and the transition to detachment folds to the north. Their geometry indicates that they were asymmetrical prior to thrust truncation. This asymmetry may have favored accommodation of increasing shortening by thrust breakthrough rather than continued folding. Fracture patterns were documented in the gently dipping panel of Lisburne and the asymmetrical folds within it. Four sets of steeply dipping extension fractures were identified, with strikes to the (1) N, (2) E, (3) N to NW, and (4) NE. The relative timing of these fracture sets is complex and unclear. En echelon sets of fractures are common, and display normal or strike-slip sense. Mesoscopic and penetrative structures are locally well developed, and indicate bed-parallel shear within the flat panel and strain within folds. Three sets of normal faults are well developed in the area, and are unusual for the Brooks Range. One set is parallel to and another is transverse to the strike of the folds. A single major normal fault has an intermediate orientation. The normal faults cut across folds, but may have been active late during folding because fold geometry differs across faults and some folding apparently continued after normal faulting.

  13. Garbage collection: an exercise in distributed, fault-tolerant programming

    SciTech Connect (OSTI)

    Vestal, S.C.

    1987-01-01

    Two garbage-collection algorithms are presented to reclaim unused storage in object-oriented systems implemented on local area networks. The algorithms are fault-tolerant and allowed parallel, incremental collection in an object address space distributed throughout the system. The two approaches allow multiple collectors, so some unused storage can be reclaimed in partitioned networks. The first method makes use of fault-tolerant reference counts together with an algorithm to collect cycles of objects that would otherwise remain unclaimed. The second method adapts a parallel collector so that it can be used to collect subspaces of the entire network address space. Throughout this work concern is with a methodology for developing distributed, parallel, fault-tolerant programs. Also, there is concern with the suitability of object-oriented systems for such applications.

  14. Multistage network with an additional stage for fault tolerance

    SciTech Connect (OSTI)

    Adams, G.B. III; Siegel, H.J.

    1982-01-01

    The extra stage cube (ESC) network, a fault tolerant structure, is proposed for use in large-scale parallel and distributed supercomputer systems. This network is derived from the generalised cube network by the addition of one stage of interchange boxes and a bypass capability for two stages. It is shown that the ESC provides fault tolerance for any single failure. Further, the network can be controlled even when it has a single failure, using a simple modification of a routing tag scheme proposed for the generalised cube. Both one-to-one and broadcast connections under routing tag control are performable by the faulted ESC. The effects of the extra stage on the partitioning and permuting abilities of the network are described. 19 references.

  15. Impact of Installation Faults on Heat Pump Performance

    SciTech Connect (OSTI)

    Hourahan, Glenn; Baxter, Van D.

    2015-01-01

    Numerous studies and surveys indicate that typically-installed HVAC equipment operate inefficiently and waste considerable energy due to varied installation errors (faults) such as improper refrigerant charge, incorrect airflow, oversized equipment, and leaky ducts. This article summarizes the results of a large United States (U.S.) experimental/analytical study (U.S. contribution to IEA HPP Annex 36) of the impact that different faults have on the performance of an air-source heat pump (ASHP) in a typical U.S. single-family house. It combines building effects, equipment effects, and climate effects in an evaluation of the faults impact on seasonal energy consumption through simulations of the house/ASHP pump system.

  16. Network resilience; A measure of network fault tolerance

    SciTech Connect (OSTI)

    Najjar, W. . Dept. of Computer Science); Gaudoit, J.L. . Dept. of Electrical Engineering)

    1990-02-01

    The failure of a node in a multicomputer system will not only reduce the computational power but also alter the network's topology. Network fault tolerance is a measure of the number of failures the network can sustain before a disconnection occurs. It is expressed traditionally as the network's node degree. In this paper, the authors propose a probabilistic measure of network fault tolerance expressed as the probability f a disconnection. Qualitative evaluation of this measure is presented. As expected, the single-node disconnection probability is the dominant factor irrespective of the topology under consideration. They derive an analytical approximation of the disconnection probability and verify it with Monte Carlo simulation. Based on this model, the measures of network resilience and relative network resilience are proposed as probabilistic measures of network fault tolerance. These are then used to evaluate the effects of the disconnection probability on the reliability of the system.

  17. Impact of Installation Faults on Heat Pump Performance

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Hourahan, Glenn; Baxter, Van D.

    2015-01-01

    Numerous studies and surveys indicate that typically-installed HVAC equipment operate inefficiently and waste considerable energy due to varied installation errors (faults) such as improper refrigerant charge, incorrect airflow, oversized equipment, and leaky ducts. This article summarizes the results of a large United States (U.S.) experimental/analytical study (U.S. contribution to IEA HPP Annex 36) of the impact that different faults have on the performance of an air-source heat pump (ASHP) in a typical U.S. single-family house. It combines building effects, equipment effects, and climate effects in an evaluation of the faults impact on seasonal energy consumption through simulations of the house/ASHPmore » pump system.« less

  18. Environmentally induced fracture of nickel alloys: a comparison of hydrogen and mercury embrittlement with respect to temperature

    SciTech Connect (OSTI)

    King, R.K.

    1985-01-01

    Previous studies have compared electrolytic hydrogen embrittlement (HE) and liquid metal embrittlement (LME) by mercury for numerous nickel alloys. All alloys tested exhibited embrittlement to some degree with HE and LME having similar fractographies. This study examines the effect of temperature on He and LME of Monel 400 over the range -30 and 80/sup 0/C. Slow strain rate tensile tests were conducted at two strain rates, 1.6 x 10/sup -5/s/sup -1/ and 1.6 x 10/sup -3/s/sup -1/, and two grain sizes, 35 ..mu..m and 250 ..mu..m. Behavior of Monel 400 is compared with previously studied nickel alloys. Results showed that intergranular, tranogranular, and microvoid-coalescence fractures can be obtained in both hydrogen and mercury. Fracture mode is governed by strain at fracture. Embrittlement ceases below -20/sup 0/ in both environment, believed due to lack of mobility of adsorbed hydrogen and lack of wetting by mercury. LME is more severe than HE because hydrogen blunts cracks by promoting plasticity. HE ceases at about 80/sup 0/C because excess plasticity promotes crack blunting and inhibits initiation. LME fractures remain brittle to 80/sup 0/C. An incubation period is normally needed for adsorption of the embrittler or for penetration of the crack through the plane stress surface zone. Otherwise ductile failures in mercury often exhibit longitudinal splitting, believed to be due to the combination of high normal stress, low shear stress, and a clean surface. The existence of a temperature window for LME can be explained on the basis of strain activated localized wetting. Results of this study are consistent with a decohesion mechanism producing intergranular fracture; competing with an enhanced dislocation nucleation mechanism producing transgranular fracture. Monel 400 exhibited the range of features observed for other nickel base alloys at appropriate conditions of temperature, strain rate, and grain size.

  19. Zero Zone Comment | Department of Energy

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    Zero Zone Comment Zero Zone Comment These comments are submitted by Zero Zone Inc., a manufacturer of CRE equipment, in response to the U.S. Department of Energy's (DOE) notice in the July 3, 2014 Federal Register requesting information to assist DOE in reviewing existing regulations and in making its regulatory program more effective and less burdensome. PDF icon Zero Zone comments More Documents & Publications Regulatory Burden RFI Executive Order 13563 certification, compliance and

  20. Adams County, Mississippi ASHRAE 169-2006 Climate Zone | Open...

    Open Energy Info (EERE)

    Adams County, Mississippi ASHRAE 169-2006 Climate Zone Jump to: navigation, search County Climate Zone Place Adams County, Mississippi ASHRAE Standard ASHRAE 169-2006 Climate Zone...

  1. Barron County, Wisconsin ASHRAE 169-2006 Climate Zone | Open...

    Open Energy Info (EERE)

    Barron County, Wisconsin ASHRAE 169-2006 Climate Zone Jump to: navigation, search County Climate Zone Place Barron County, Wisconsin ASHRAE Standard ASHRAE 169-2006 Climate Zone...

  2. Becker County, Minnesota ASHRAE 169-2006 Climate Zone | Open...

    Open Energy Info (EERE)

    Becker County, Minnesota ASHRAE 169-2006 Climate Zone Jump to: navigation, search County Climate Zone Place Becker County, Minnesota ASHRAE Standard ASHRAE 169-2006 Climate Zone...

  3. Anderson County, Kentucky ASHRAE 169-2006 Climate Zone | Open...

    Open Energy Info (EERE)

    Anderson County, Kentucky ASHRAE 169-2006 Climate Zone Jump to: navigation, search County Climate Zone Place Anderson County, Kentucky ASHRAE Standard ASHRAE 169-2006 Climate Zone...

  4. Atkinson County, Georgia ASHRAE 169-2006 Climate Zone | Open...

    Open Energy Info (EERE)

    Atkinson County, Georgia ASHRAE 169-2006 Climate Zone Jump to: navigation, search County Climate Zone Place Atkinson County, Georgia ASHRAE Standard ASHRAE 169-2006 Climate Zone...

  5. Alfalfa County, Oklahoma ASHRAE 169-2006 Climate Zone | Open...

    Open Energy Info (EERE)

    Alfalfa County, Oklahoma ASHRAE 169-2006 Climate Zone Jump to: navigation, search County Climate Zone Place Alfalfa County, Oklahoma ASHRAE Standard ASHRAE 169-2006 Climate Zone...

  6. Central Nevada Seismic Zone Geothermal Region | Open Energy Informatio...

    Open Energy Info (EERE)

    Central Nevada Seismic Zone Geothermal Region (Redirected from Central Nevada Seismic Zone) Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Central Nevada Seismic Zone...

  7. An Advanced Fracture Characterization and Well Path Navigation System for Effective Re-Development and Enhancement of Ultimate Recovery from the Complex Monterey Reservoir of South Ellwood Field, Offshore California

    SciTech Connect (OSTI)

    Steve Horner

    2006-01-31

    Venoco Inc, intends to re-develop the Monterey Formation, a Class III basin reservoir, at South Ellwood Field, Offshore Santa Barbara, California. Well productivity in this field varies significantly. Cumulative Monterey production for individual wells has ranged from 260 STB to 8,700,000 STB. Productivity is primarily affected by how well the well path connects with the local fracture system and the degree of aquifer support. Cumulative oil recovery to date is a small percentage of the original oil in place. To embark upon successful re-development and to optimize reservoir management, Venoco intends to investigate, map and characterize field fracture patterns and the reservoir conduit system. State of the art borehole imaging technologies including FMI, dipole sonic and cross-well seismic, interference tests and production logs will be employed to characterize fractures and micro faults. These data along with the existing database will be used for construction of a novel geologic model of the fracture network. Development of an innovative fracture network reservoir simulator is proposed to monitor and manage the aquifer's role in pressure maintenance and water production. The new fracture simulation model will be used for both planning optimal paths for new wells and improving ultimate recovery. In the second phase of this project, the model will be used for the design of a pilot program for downhole water re-injection into the aquifer simultaneously with oil production. Downhole water separation units attached to electric submersible pumps will be used to minimize surface fluid handling thereby improving recoveries per well and field economics while maintaining aquifer support. In cooperation with the DOE, results of the field studies as well as the new models developed and the fracture database will be shared with other operators. Numerous fields producing from the Monterey and analogous fractured reservoirs both onshore and offshore will benefit from the methodologies developed in this project. This report presents a summary of all technical work conducted during the ninth quarter of Budget Period II.

  8. AN ADVANCED FRACTURE CHARACTERIZATION AND WELL PATH NAVIGATION SYSTEM FOR EFFECTIVE RE-DEVELOPMENT AND ENHANCEMENT OF ULTIMATE RECOVERY FROM THE COMPLEX MONTEREY RESERVOIR OF SOUTH ELLWOOD FIELD, OFFSHORE CALIFORNIA

    SciTech Connect (OSTI)

    Steve Horner

    2005-08-01

    Venoco Inc, intends to re-develop the Monterey Formation, a Class III basin reservoir, at South Ellwood Field, Offshore Santa Barbara, California. Well productivity in this field varies significantly. Cumulative Monterey production for individual wells has ranged from 260 STB to 8,700,000 STB. Productivity is primarily affected by how well the well path connects with the local fracture system and the degree of aquifer support. Cumulative oil recovery to date is a small percentage of the original oil in place. To embark upon successful re-development and to optimize reservoir management, Venoco intends to investigate, map and characterize field fracture patterns and the reservoir conduit system. State of the art borehole imaging technologies including FMI, dipole sonic and cross-well seismic, interference tests and production logs will be employed to characterize fractures and micro faults. These data along with the existing database will be used for construction of a novel geologic model of the fracture network. Development of an innovative fracture network reservoir simulator is proposed to monitor and manage the aquifer's role in pressure maintenance and water production. The new fracture simulation model will be used for both planning optimal paths for new wells and improving ultimate recovery. In the second phase of this project, the model will be used for the design of a pilot program for downhole water re-injection into the aquifer simultaneously with oil production. Downhole water separation units attached to electric submersible pumps will be used to minimize surface fluid handling thereby improving recoveries per well and field economics while maintaining aquifer support. In cooperation with the DOE, results of the field studies as well as the new models developed and the fracture database will be shared with other operators. Numerous fields producing from the Monterey and analogous fractured reservoirs both onshore and offshore will benefit from the methodologies developed in this project. This report presents a summary of all technical work conducted during the seventh quarter of Budget Period II.

  9. High voltage fault current limiter having immersed phase coils

    DOE Patents [OSTI]

    Darmann, Francis Anthony

    2014-04-22

    A fault current limiter including: a ferromagnetic circuit formed from a ferromagnetic material and including at least a first limb, and a second limb; a saturation mechanism surrounding a limb for magnetically saturating the ferromagnetic material; a phase coil wound around a second limb; a dielectric fluid surrounding the phase coil; a gaseous atmosphere surrounding the saturation mechanism.

  10. Experimental and computational studies on stacking faults in zinc titanate

    SciTech Connect (OSTI)

    Sun, W.; Ageh, V.; Mohseni, H.; Scharf, T. W. E-mail: Jincheng.Du@unt.edu; Du, J. E-mail: Jincheng.Du@unt.edu

    2014-06-16

    Zinc titanate (ZnTiO{sub 3}) thin films grown by atomic layer deposition with ilmenite structure have recently been identified as an excellent solid lubricant, where low interfacial shear and friction are achieved due to intrafilm shear velocity accommodation in sliding contacts. In this Letter, high resolution transmission electron microscopy with electron diffraction revealed that extensive stacking faults are present on ZnTiO{sub 3} textured (104) planes. These growth stacking faults serve as a pathway for dislocations to glide parallel to the sliding direction and hence achieve low interfacial shear/friction. Generalized stacking fault energy plots also known as ?-surfaces were computed for the (104) surface of ZnTiO{sub 3} using energy minimization method with classical effective partial charge potential and verified by using density functional theory first principles calculations for stacking fault energies along certain directions. These two are in qualitative agreement but classical simulations generally overestimate the energies. In addition, the lowest energy path was determined to be along the [451{sup }] direction and the most favorable glide system is (104) ?451{sup }? that is responsible for the experimentally observed sliding-induced ductility.

  11. Faulted reservoirs characterization by an image processing technique

    SciTech Connect (OSTI)

    Martinez-Angeles, R.

    1994-12-31

    This paper has developed an image processing method for obtaining the discontinuous areal distribution of oil parameters (formation top, porosity, water saturation,...) of faulted heterogeneous oil reservoirs. For its application it requires the previous knowledge of a set of discrete values z(k,l) from well-logs and seismic profiles. Faulted structures were discretized into continuous structures or blocks bounded by faults. The theoretical fundamental assumption of the proposed method establishes that the natural distributions can be considered as the superposition of several elementary brownian distributions, represented by discrete values z(k,l), whose physical model is the diffusion differential equation and its solution associated. This is a technique that allows the representation of a composed brownian distribution as a linear combination of all elementary brownian functions. For illustrating the operational aspect of brownian analysis, two examples are studied. The results are presented as a digital images by means of an image processing software. This method can be applied in mapping, three dimensions interpolation and reserves calculation of faulted reservoirs.

  12. Effects of Fusion Zone Size and Failure Mode on Peak Load and Energy Absorption of Advanced High Strength Steel Spot Welds

    SciTech Connect (OSTI)

    Sun, Xin; Stephens, Elizabeth V.; Khaleel, Mohammad A.

    2007-01-01

    This paper examines the effects of fusion zone size on failure modes, static strength and energy absorption of resistance spot welds (RSW) of advanced high strength steels (AHSS). DP800 and TRIP800 spot welds are considered. The main failure modes for spot welds are nugget pullout and interfacial fracture. Partial interfacial fracture is also observed. The critical fusion zone sizes to ensure nugget pull-out failure mode are developed for both DP800 and TRIP800 using limit load based analytical model and micro-hardness measurements of the weld cross sections. Static weld strength tests using cross tension samples were performed on the joint populations with controlled fusion zone sizes. The resulted peak load and energy absorption levels associated with each failure mode were studied for all the weld populations using statistical data analysis tools. The results in this study show that AHSS spot welds with fusion zone size of can not produce nugget pullout mode for both the DP800 and TRIP800 materials examined. The critical fusion zone size for nugget pullout shall be derived for individual materials based on different base metal properties as well as different heat affected zone (HAZ) and weld properties resulted from different welding parameters.

  13. The shear fracture toughness, KIIc, of graphite

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Burchell, Timothy D.; Erdman, III, Donald L.

    2015-11-05

    In this study, the critical shear stress intensity factor, KIIc, here-in referred to as the shear fracture toughness, KIIc (MPa m), of two grades of graphite are reported. The range of specimen volumes was selected to elucidate any specimen size effect, but smaller volume specimen tests were largely unsuccessful, shear failure did not occur between the notches as expected. This was probably due to the specimen geometry causing the shear fracture stress to exceed the compressive failure stress. In subsequent testing the specimen geometry was altered to reduce the compressive footprint and the notches (slits) made deeper to reduce themore » specimen's ligament length. Additionally, we added the collection of Acoustic Emission (AE) during testing to assist with the identification of the shear fracture load. The means of KIIc from large specimens for PCEA and NBG-18 are 2.26 MPa m with an SD of 0.37 MPa m and 2.20 MPa m with an SD of 0.53 MPa m, respectively. The value of KIIc for both graphite grades was similar, although the scatter was large. In this work we found the ratio of KIIc/KIc ≈ 1.6. .« less

  14. FRACTURE FAILURE CRITERIA OF SOFC PEN STRUCTURE

    SciTech Connect (OSTI)

    Liu, Wenning N.; Sun, Xin; Khaleel, Mohammad A.; Qu, Jianmin

    2007-04-30

    Thermal stresses and warpage of the PEN are unavoidable due to the temperature changes from the stress-free sintering temperature to room temperature and mismatch of the coefficients of thermal expansion (CTE) of various layers in the PEN structures of solid oxide fuel cells (SOFC) during the PEN manufacturing process. In the meantime, additional mechanical stresses will also be created by mechanical flattening during the stack assembly process. The porous nature of anode and cathode in the PEN structures determines presence of the initial flaws and crack on the interfaces of anode/electrolyte/cathode and in the interior of the materials. The sintering/assembling induced stresses may cause the fracture failure of PEN structure. Therefore, fracture failure criteria for SOFC PEN structures is developed in order to ensure the structural integrity of the cell and stack of SOFC. In this paper, the fracture criteria based on the relationship between the critical energy release rate and critical curvature and maximum displacement of the warped cells caused by the temperature changes as well as mechanical flattening process is established so that possible failure of SOFC PEN structures may be predicted deterministically by the measurement of the curvature and displacement of the warped cells.

  15. Naturally fractured reservoirs: Optimized E and P strategies using a reaction-transport-mechanical simulator in an integrated approach. Annual report, 1996--1997

    SciTech Connect (OSTI)

    Hoak, T.; Jenkins, R.; Ortoleva, P.; Ozkan, G.; Shebl, M.; Sibo, W.; Tuncay, K.; Sundberg, K.

    1998-07-01

    The methodology and results of this project are being tested using the Andector-Goldsmith Field in the Permian Basin, West Texas. The study area includes the Central Basin Platform and the Midland Basin. The Andector-Goldsmith Field lies at the juncture of these two zones in the greater West Texas Permian Basin. Although the modeling is being conducted in this area, the results have widespread applicability to other fractured carbonate and other reservoirs throughout the world.

  16. Property:ASHRAE 169 Climate Zone Subtype | Open Energy Information

    Open Energy Info (EERE)

    A + Adair County, Oklahoma ASHRAE 169-2006 Climate Zone + Climate Zone Subtype A + Adams County, Colorado ASHRAE 169-2006 Climate Zone + Climate Zone Subtype B + Adams County,...

  17. Property:ASHRAE 169 Climate Zone Number | Open Energy Information

    Open Energy Info (EERE)

    5 + Adair County, Oklahoma ASHRAE 169-2006 Climate Zone + Climate Zone Number 3 + Adams County, Colorado ASHRAE 169-2006 Climate Zone + Climate Zone Number 5 + Adams County,...

  18. U.S. Climate Zones Map for Commercial Buildings

    U.S. Energy Information Administration (EIA) Indexed Site

    U.S. Climate Zone U. S. Climate Zones for 2003 CBECS: climate zones map Note:Map updated with corrections, February 2012 Further Explanation on How Climate Zones are Defined...

  19. U.S. Climate Zones Map for Commercial Buildings

    U.S. Energy Information Administration (EIA) Indexed Site

    Past Climate Zones U. S. Climate Zones for 1979-1999 CBECS: climate zone map Return to Climate Zones for 2003 CBECS Return to CBECS Home Page Note:Map updated with corrections,...

  20. Study of Reservoir Heterogencities and Structural Features Affecting Production in the Shallow Oil Zone, Eastern Elk Hills Area, California

    SciTech Connect (OSTI)

    Janice Gillespie

    2004-11-01

    Late Neogene (Plio-Pleistocene) shallow marine strata of the western Bakersfield Arch and Elk Hills produce hydrocarbons from several different reservoirs. This project focuses on the shallow marine deposits of the Gusher and Calitroleum reservoirs in the Lower Shallow Oil Zone (LSOZ). In the eastern part of the study area on the Bakersfield Arch at North and South Coles Levee field and in two wells in easternmost Elk Hills, the LSOZ reservoirs produce dry (predominantly methane) gas. In structurally higher locations in western Elk Hills, the LSOZ produces oil and associated gas. Gas analyses show that gas from the eastern LSOZ is bacterial and formed in place in the reservoirs, whereas gas associated with oil in the western part of the study area is thermogenic and migrated into the sands from deeper in the basin. Regional mapping shows that the gas-bearing LSOZ sands in the Coles Levee and easternmost Elk Hills area are sourced from the Sierra Nevada to the east whereas the oil-bearing sands in western Elk Hills appear to be sourced from the west. The eastern Elk Hills area occupied the basin depocenter, farthest from either source area. As a result, it collected mainly low-permeability offshore shale deposits. This sand-poor depocenter provides an effective barrier to the updip migration of gases from east to west. The role of small, listric normal faults as migration barriers is more ambiguous. Because our gas analyses show that the gas in the eastern LSOZ reservoirs is bacterial, it likely formed in-place near the reservoirs and did not have to migrate far. Therefore, the gas could have been generated after faulting and accumulated within the fault blocks as localized pools. However, bacterial gas is present in both the eastern AND western parts of Elk Hills in the Dry Gas Zone (DGZ) near the top of the stratigraphic section even though the measured fault displacement is greatest in this zone. Bacterial gas is not present in the west in the deeper LSOZ which has less measured fault displacement. The main difference between the DGZ and the LSOZ appears to be the presence of a sandpoor area in the LSOZ in eastern Elk Hills. The lack of permeable migration pathways in this area would not allow eastern bacterial gas to migrate farther updip into western Elk Hills. A similar sand-poor area does not appear to exist in the DGZ but future research may be necessary to verify this.

  1. Advanced reservoir characterization and evaluation of CO2 gravity drainage in the naturally fractured Spraberry Trend Area. Annual report, September 1, 1996--August 31, 1997

    SciTech Connect (OSTI)

    McDonald, P.

    1998-06-01

    The objective of the Spraberry CO{sub 2} pilot project is to determine the technical and economic feasibility of continuous CO{sub 2} injection in the naturally fractured reservoirs of the Spraberry Trend. In order to describe, understand, and model CO{sub 2} flooding in the naturally fractured Spraberry reservoirs, characterization of the fracture system is a must. Additional reservoir characterization was based on horizontal coring in the second year of the project. In addition to characterization of natural fractures, horizontal coring has confirmed a previously developed rock model for describing the Spraberry Trend shaly sands. A better method for identifying Spraberry pay zones has been verified. The authors have completed the reservoir characterization, which includes matrix description and detection (from core-log integration) and fracture characterization. This information is found in Section 1. The authors have completed extensive imbibition experiments that strongly indicate that the weakly water-wet behavior of the reservoir rock may be responsible for poor waterflood response observed in many Spraberry fields. The authors have also made significant progress in analytical and numerical simulation of performance in Spraberry reservoirs as seen in Section 3. They have completed several suites of CO{sub 2} gravity drainage in Spraberry and Berea whole cores at reservoir conditions and reported in Section 4. The results of these experiments have been useful in developing a model for free-fall gravity drainage and have validated the premise that CO{sub 2} will recover oil from tight, unconfined Spraberry matrix.

  2. Applied Field Research Initiative Deep Vadose Zone

    Office of Environmental Management (EM)

    Applied Field Research Initiative Deep Vadose Zone Located on the Hanford Site in Richland, Washington, the Deep Vadose Zone Applied Field Research Initiative (DVZ AFRI) was established to protect water resources by addressing the challenge of preventing contamination in the deep vadose zone from reaching groundwater. Led by the Pacific Northwest National Laboratory, the Initiative is a collaborative effort that leverages Department of Energy (DOE) investments in basic science and applied

  3. Controlling Subsurface Fractures and Fluid Flow: A Basic Research Agenda |

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    Department of Energy Controlling Subsurface Fractures and Fluid Flow: A Basic Research Agenda Controlling Subsurface Fractures and Fluid Flow: A Basic Research Agenda PDF icon BES Report Controlling Subsurface Fractures and Fluid Flow.pdf More Documents & Publications AGU SubTER Town Hall Presentation 2015 SubTER Grand Challenge Roundtable: Imaging Geophysical and Geochemical Signals in the Subsurface SubTER Crosscut White Paper

  4. Irradiation Effects on Human Cortical Bone Fracture Behavior

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Irradiation Effects on Human Cortical Bone Fracture Behavior Print Human bone is strong but still fallible. To better predict fracturing in bone, researchers need a mechanistic framework to understand the changes taking place on different size scales within bone, as well as the role of sustained irradiation damage. Combining in situ mechanical testing with synchrotron x-ray diffraction imaging and/or tomography, is a popular method of investigating micrometer deformation and fracture behavior in

  5. Irradiation Effects on Human Cortical Bone Fracture Behavior

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Irradiation Effects on Human Cortical Bone Fracture Behavior Print Human bone is strong but still fallible. To better predict fracturing in bone, researchers need a mechanistic framework to understand the changes taking place on different size scales within bone, as well as the role of sustained irradiation damage. Combining in situ mechanical testing with synchrotron x-ray diffraction imaging and/or tomography, is a popular method of investigating micrometer deformation and fracture behavior in

  6. Irradiation Effects on Human Cortical Bone Fracture Behavior

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Irradiation Effects on Human Cortical Bone Fracture Behavior Print Human bone is strong but still fallible. To better predict fracturing in bone, researchers need a mechanistic framework to understand the changes taking place on different size scales within bone, as well as the role of sustained irradiation damage. Combining in situ mechanical testing with synchrotron x-ray diffraction imaging and/or tomography, is a popular method of investigating micrometer deformation and fracture behavior in

  7. Irradiation Effects on Human Cortical Bone Fracture Behavior

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Irradiation Effects on Human Cortical Bone Fracture Behavior Print Human bone is strong but still fallible. To better predict fracturing in bone, researchers need a mechanistic framework to understand the changes taking place on different size scales within bone, as well as the role of sustained irradiation damage. Combining in situ mechanical testing with synchrotron x-ray diffraction imaging and/or tomography, is a popular method of investigating micrometer deformation and fracture behavior in

  8. Irradiation Effects on Human Cortical Bone Fracture Behavior

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Irradiation Effects on Human Cortical Bone Fracture Behavior Irradiation Effects on Human Cortical Bone Fracture Behavior Print Wednesday, 28 July 2010 00:00 Human bone is strong but still fallible. To better predict fracturing in bone, researchers need a mechanistic framework to understand the changes taking place on different size scales within bone, as well as the role of sustained irradiation damage. Combining in situ mechanical testing with synchrotron x-ray diffraction imaging and/or

  9. Predicting fracture in micron-scale polycrystalline silicon MEMS

    Office of Scientific and Technical Information (OSTI)

    structures. (Technical Report) | SciTech Connect Technical Report: Predicting fracture in micron-scale polycrystalline silicon MEMS structures. Citation Details In-Document Search Title: Predicting fracture in micron-scale polycrystalline silicon MEMS structures. Designing reliable MEMS structures presents numerous challenges. Polycrystalline silicon fractures in a brittle manner with considerable variability in measured strength. Furthermore, it is not clear how to use a measured tensile

  10. Irradiation Effects on Human Cortical Bone Fracture Behavior

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Irradiation Effects on Human Cortical Bone Fracture Behavior Print Human bone is strong but still fallible. To better predict fracturing in bone, researchers need a mechanistic framework to understand the changes taking place on different size scales within bone, as well as the role of sustained irradiation damage. Combining in situ mechanical testing with synchrotron x-ray diffraction imaging and/or tomography, is a popular method of investigating micrometer deformation and fracture behavior in

  11. Irradiation Effects on Human Cortical Bone Fracture Behavior

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Irradiation Effects on Human Cortical Bone Fracture Behavior Print Human bone is strong but still fallible. To better predict fracturing in bone, researchers need a mechanistic framework to understand the changes taking place on different size scales within bone, as well as the role of sustained irradiation damage. Combining in situ mechanical testing with synchrotron x-ray diffraction imaging and/or tomography, is a popular method of investigating micrometer deformation and fracture behavior in

  12. Orbital apex fractures: the contribution of computed tomography

    SciTech Connect (OSTI)

    Unger, J.M.

    1984-03-01

    The conventional radiographs, computed tomograms, and clinical course of 17 patients with 23 orbital apex fractures were reviewed. The type of fracture was identified, and the presence of optic nerve damage, the superior orbital fissure syndrome, or the orbital apex syndrome was noted. It was concluded that fractures of the orbital apex may frequently be unsuspected clinically and are not as rare as the literature indicates. Computed tomography provides an excellent means of radiologic diagnosis in the acutely traumatized patient.

  13. Numerical solution of sand transport in hydraulic fracturing

    SciTech Connect (OSTI)

    Daneshy, A.A.; Crichlow, H.B.

    1980-02-07

    A numerical solution is developed for the deposition of a propping agent inside a hydraulic fracture. Such parameters as fluid leak-off into the formation, increase in sand concentration caused by leak-off, non-Newtonian fracturing fluids, hindered settling velocity, and an up-to-date geometry are taken into consideration. Three examples investigate the proppant deposition for low-, medium-, and high-viscosity fracturing fluids.

  14. Development of Asset Fault Signatures for Prognostic and Health Management in the Nuclear Industry

    SciTech Connect (OSTI)

    Vivek Agarwal; Nancy J. Lybeck; Randall Bickford; Richard Rusaw

    2014-06-01

    Proactive online monitoring in the nuclear industry is being explored using the Electric Power Research Institute’s Fleet-Wide Prognostic and Health Management (FW-PHM) Suite software. The FW-PHM Suite is a set of web-based diagnostic and prognostic tools and databases that serves as an integrated health monitoring architecture. The FW-PHM Suite has four main modules: Diagnostic Advisor, Asset Fault Signature (AFS) Database, Remaining Useful Life Advisor, and Remaining Useful Life Database. This paper focuses on development of asset fault signatures to assess the health status of generator step-up generators and emergency diesel generators in nuclear power plants. Asset fault signatures describe the distinctive features based on technical examinations that can be used to detect a specific fault type. At the most basic level, fault signatures are comprised of an asset type, a fault type, and a set of one or more fault features (symptoms) that are indicative of the specified fault. The AFS Database is populated with asset fault signatures via a content development exercise that is based on the results of intensive technical research and on the knowledge and experience of technical experts. The developed fault signatures capture this knowledge and implement it in a standardized approach, thereby streamlining the diagnostic and prognostic process. This will support the automation of proactive online monitoring techniques in nuclear power plants to diagnose incipient faults, perform proactive maintenance, and estimate the remaining useful life of assets.

  15. High resolution, shallow seismic reflection survey of the Pen Branch fault

    SciTech Connect (OSTI)

    Stieve, A.

    1991-05-15

    The purpose of this project, at the Savannah River River Site (SRS) was to acquire, process, and interpret 28 km (17.4 miles) of high resolution seismic reflection data taken across the trace of the Pen Branch fault and other suspected, intersecting north-south trending faults. The survey was optimized for the upper 300 ft of geologic strata in order to demonstrate the existence of very shallow, flat lying horizons, and to determine the depth of the fault or to sediments deformed by the fault. Field acquisition and processing parameters were selected to define small scale spatial variability and structural features in the vicinity of the Pen Branch fault leading to the definition and the location of the Pen Branch fault, the shallowest extent of the fault, and the quantification of the sense and magnitude of motion. Associated geophysical, borehole, and geologic data were incorporated into the investigation to assist in the determination of optimal parameters and aid in the interpretation.

  16. Washington Coastal Zone Management Regulatory Handbook | Open...

    Open Energy Info (EERE)

    to library PermittingRegulatory Guidance - GuideHandbook: Washington Coastal Zone Management Regulatory HandbookPermittingRegulatory GuidanceGuideHandbook Author Washington...

  17. Mapping Hydrothermal Upwelling and Outflow Zones: Preliminary...

    Open Energy Info (EERE)

    temperature anomaly has been mapped. A group of subtle temperature anomalies along Simpson Pass, south of the current production area, are interpreted as an upwelling zone with...

  18. Coastal Zone Management Act and Regulations (NOAA)

    Broader source: Energy.gov [DOE]

    The Coastal Zone Management Act (CZMA) of 1972 provides for the management of the nation’s coastal resources, including the Great Lakes.

  19. Climate Zone 2B | Open Energy Information

    Open Energy Info (EERE)

    are categorized as class 2B climate zones: Bandera County, Texas Dimmit County, Texas Edwards County, Texas Frio County, Texas Imperial County, California Kinney County, Texas La...

  20. Coastal Zone Management Act | Open Energy Information

    Open Energy Info (EERE)

    and the National Estuarine Research Reserve System. The 34 coastal programs aim to balance competing land and water issues in the coastal zone, while estuarine reserves serve...

  1. Coastal Zone Management Act and Regulations

    Broader source: Energy.gov [DOE]

    The Coastal Zone Management Act (CZMA) of 1972 provides for the management of the nation’s coastal resources, including the Great Lakes.

  2. Vadose Zone Microbiology: Science and Applications

    SciTech Connect (OSTI)

    Brockman, Fred J.; Bradley, Stephen D.; Kieft, Thomas L.

    2002-03-12

    Brockman FJ, SN Bradley and TL Kieft. 2002. Vadose zone microbiology. In Encyclopedia of Environmental Microbiology, volume 6, pp. 3236-3246. John Wiley and Sons, New York.

  3. Maricopa County- Renewable Energy Systems Zoning Ordinance

    Broader source: Energy.gov [DOE]

    The Maricopa County Zoning Ordinance contains provisions for siting renewable energy systems. The ordinance defines renewable energy as "energy derived primarily from sources other than fossil...

  4. Hydraulic Fracturing Data Collection Tools Improve Environmental Reporting, Monitoring, Protection

    Broader source: Energy.gov [DOE]

    Two data collection tools specifically developed for hydraulic fracturing are available to help regulatory agencies monitor drilling and completion operations and enhance environmental protection.

  5. Thermal-hydrologic-mechanical behavior of single fractures in...

    Office of Scientific and Technical Information (OSTI)

    Conference: Thermal-hydrologic-mechanical behavior of single fractures in EGS reservoirs Citation Details In-Document Search Title: Thermal-hydrologic-mechanical behavior of single ...

  6. Poroelastic modeling of fracture-seismic wave interaction (Journal...

    Office of Scientific and Technical Information (OSTI)

    and hydraulic properties are examined. From parametric studies, we found that the hydraulic permeability of a fracture fully saturated with water has little impact on ...

  7. Microseismicity, stress, and fracture in the Coso geothermal...

    Open Energy Info (EERE)

    Microseismicity, stress, and fracture in the Coso geothermal field, California Jump to: navigation, search OpenEI Reference LibraryAdd to library Journal Article: Microseismicity,...

  8. Characterizing Fractures in Geysers Geothermal Field by Micro...

    Open Energy Info (EERE)

    cooling shrinkage. The stimulated, existing fractures thus enhance the permeability of the hot rock formations, hence enabling better circulation of water for the...

  9. Intrusion Margins and Associated Fractures | Open Energy Information

    Open Energy Info (EERE)

    Rim Margins Lithologically Controlled Fractures caused by igneous activity creates permeability, allowing water to circulate deep beneath the surface thus becoming heated in the...

  10. Reservoir-Scale Fracture Permeability in the Dixie Valley, Nevada...

    Open Energy Info (EERE)

    Reservoir-Scale Fracture Permeability in the Dixie Valley, Nevada, Geothermal Field Jump to: navigation, search OpenEI Reference LibraryAdd to library Conference Paper:...

  11. Dispersed Fluid Flow in Fractured Reservoirs- an Analysis of...

    Open Energy Info (EERE)

    Reservoirs- an Analysis of Tracer-Determined Residence Time Distributions Abstract A methodology for analyzing the internal flow characteristics of a fractured geothermal reservoir...

  12. Characterization Of Fracture Patterns In The Geysers Geothermal...

    Open Energy Info (EERE)

    Also, graphical fracture characterizations in the form of equal-area projections and rose diagrams were created to depict the results. The main crack orientations within the...

  13. Fracture orientation analysis by the solid earth tidal strain...

    Open Energy Info (EERE)

    method has been successfully demonstrated at a naturally fractured geothermal field (Raft River) in Southeastern Idaho and at an oil field in Western Canada. Both case studies...

  14. Tracer Methods for Characterizing Fracture Stimulation in Enhanced...

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    Stimulation in Enhanced Geothermal Systems (EGS); 2010 Geothermal Technology Program Peer Review Report Tracer Methods for Characterizing Fracture Stimulation in Enhanced...

  15. Fracture Characterization in Enhanced Geothermal Systems by Wellbore...

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    Characterization in Enhanced Geothermal Systems by Wellbore and Reservoir Analysis; 2010 Geothermal Technology Program Peer Review Report Fracture Characterization in Enhanced ...

  16. A Shallow Attenuating Anomaly Inside The Ring Fracture Of The...

    Open Energy Info (EERE)

    Roberts,Keiiti Aki,Michael C. Fehler. 1995. A Shallow Attenuating Anomaly Inside The Ring Fracture Of The Valles Caldera, New Mexico. Journal of Volcanology and Geothermal...

  17. Project Captures First-Ever Comprehensive Hydraulic Fracturing...

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    April 6, 2016 - 1:51pm Addthis Data acquisition under the project included- Comprehensive geophysical well logs Side wall cores Diagnostic fracture injection tests Cross-well ...

  18. Interaction and Coalescence of Nanovoids and Dynamic Fracture...

    Office of Scientific and Technical Information (OSTI)

    of Nanovoids and Dynamic Fracture in Silica Glass: Multimiilion-to-Billion Atom Molecular Dynamics Simulations Citation Details In-Document Search Title: Interaction and...

  19. Using supercritical carbon dioxide as a fracturing fluid

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    compare different working models of hydraulic fracturing for shale gas and oil production. ... and drawbacks of using supercritical CO2 as a working fluid for shale gas production. ...

  20. A Simple, Fast Method of Estimating Fractured Reservoir Geometry...

    Open Energy Info (EERE)

    Fractured Reservoir Geometry from Tracer Tests Abstract A simple method of estimating flow geometry and pore geometry from conservative tracer tests in single phase geothermal...

  1. Fracture Network and Fluid Flow Imaging for EGS Applications...

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    Network and Fluid Flow Imaging for EGS Applications from Multi-Dimensional Electrical Resistivity Structure Fracture Network and Fluid Flow Imaging for EGS Applications from ...

  2. International Collaborations on Fluid Flows in Fractured Crystalline...

    Office of Scientific and Technical Information (OSTI)

    International Collaborations on Fluid Flows in Fractured Crystalline Rocks: FY14 Progress Report. Citation Details In-Document Search Title: International Collaborations on Fluid ...

  3. Tracer Methods for Characterizing Fracture Creation in Enhanced...

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    Tracer Methods for Characterizing Fracture Creation in Enhanced Geothermal Systems; 2010 ... Systems by Wellbore and Reservoir Analysis; 2010 Geothermal Technology Program Peer ...

  4. Thermal-hydrologic-mechanical behavior of single fractures in...

    Office of Scientific and Technical Information (OSTI)

    (LANL) Sponsoring Org: DOE Country of Publication: United States Language: English Subject: 15 GEOTHERMAL ENERGY; 58 GEOSCIENCES; BEHAVIOR; FRACTURES; GEOTHERMAL SYSTEMS; MEETINGS

  5. Advanced Hydraulic Fracturing Technology for Unconventional Tight Gas Reservoirs

    SciTech Connect (OSTI)

    Stephen Holditch; A. Daniel Hill; D. Zhu

    2007-06-19

    The objectives of this project are to develop and test new techniques for creating extensive, conductive hydraulic fractures in unconventional tight gas reservoirs by statistically assessing the productivity achieved in hundreds of field treatments with a variety of current fracturing practices ranging from 'water fracs' to conventional gel fracture treatments; by laboratory measurements of the conductivity created with high rate proppant fracturing using an entirely new conductivity test - the 'dynamic fracture conductivity test'; and by developing design models to implement the optimal fracture treatments determined from the field assessment and the laboratory measurements. One of the tasks of this project is to create an 'advisor' or expert system for completion, production and stimulation of tight gas reservoirs. A central part of this study is an extensive survey of the productivity of hundreds of tight gas wells that have been hydraulically fractured. We have been doing an extensive literature search of the SPE eLibrary, DOE, Gas Technology Institute (GTI), Bureau of Economic Geology and IHS Energy, for publicly available technical reports about procedures of drilling, completion and production of the tight gas wells. We have downloaded numerous papers and read and summarized the information to build a database that will contain field treatment data, organized by geographic location, and hydraulic fracture treatment design data, organized by the treatment type. We have conducted experimental study on 'dynamic fracture conductivity' created when proppant slurries are pumped into hydraulic fractures in tight gas sands. Unlike conventional fracture conductivity tests in which proppant is loaded into the fracture artificially; we pump proppant/frac fluid slurries into a fracture cell, dynamically placing the proppant just as it occurs in the field. From such tests, we expect to gain new insights into some of the critical issues in tight gas fracturing, in particular the roles of gel damage, polymer loading (water-frac versus gel frac), and proppant concentration on the created fracture conductivity. To achieve this objective, we have designed the experimental apparatus to conduct the dynamic fracture conductivity tests. The experimental apparatus has been built and some preliminary tests have been conducted to test the apparatus.

  6. Application of the directional hydraulic fracturing at Berezovskaya Mine

    SciTech Connect (OSTI)

    Lekontsev, Y.M.; Sazhin, P.V.

    2008-05-15

    The paper analyzes the experimental research of the directional hydraulic fracturing applied for weakening of rocks at Berezovskaya Mine (Kuznetsk Coal Basin) in 2005-2006.

  7. Carbon Dioxide Geological Sequestration in Fractured Porous Rocks

    Office of Scientific and Technical Information (OSTI)

    Training and Research on Probabilistic Hydro-Thermo-Mechanical Modeling of Carbon Dioxide Geological Sequestration in Fractured Porous Rocks Gutierrez, Marte 54 ENVIRONMENTAL...

  8. Three-dimensional Modeling of Fracture Clusters in Geeothermal Reservoirs

    Broader source: Energy.gov [DOE]

    Three-dimensional Modeling of Fracture Clusters in Geeothermal Reservoirs presentation at the April 2013 peer review meeting held in Denver, Colorado.

  9. Pressure Testing of a High Temperature Naturally Fractured Reservoir...

    Office of Scientific and Technical Information (OSTI)

    and flow-through tests at the Hot Dry rock (HDR) test site at Fenton Hill, New Mexico. ... FRACTURING; FRESH WATER; GRANITES; NEW MEXICO; PERMEABILITY; POROSITY; PUMPING; ...

  10. Shale Gas Application in Hydraulic Fracturing Market is likely...

    Open Energy Info (EERE)

    on unconventional reservoirs such as coal bed methane, tight gas, tight oil, shale gas, and shale oil. Over the period of time, hydraulic fracturing technique has found...

  11. Studies of Transport Properties of Fractures: Final Report

    SciTech Connect (OSTI)

    Stephen R. Brown

    2006-06-30

    We proposed to study several key factors controlling the character and evolution of fracture system permeability and transport processes. We suggest that due to surface roughness and the consequent channeling in single fractures and in fracture intersections, the tendency of a fracture system to plug up, remain permeable, or for permeability to increase due to chemical dissolution/precipitation conditions will depend strongly on the instantaneous flow channel geometry. This geometry will change as chemical interaction occurs, thus changing the permeability through time. To test this hypothesis and advance further understanding toward a predictive capability, we endeavored to physically model and analyze several configurations of flow and transport of inert and chemically active fluids through channels in single fractures and through fracture intersections. This was an integrated program utilizing quantitative observations of fractures and veins in drill core, quantitative and visual observations of flow and chemical dissolution and precipitation within replicas of real rough-walled fractures and fracture intersections, and numerical modeling via lattice Boltzmann methods.

  12. Finding Large Aperture Fractures in Geothermal Resource Areas...

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    Long-Offset Surface Seismic Survey Finding Large Aperture Fractures in Geothermal Resource Areas Using a Three-Component Long-Offset Surface Seismic Survey DOE ...

  13. Analysis Of Macroscopic Fractures In Granite In The Hdr Geothermal...

    Open Energy Info (EERE)

    natural fractures at low pressures, and to create a geothermal reservoir. Authors Albert Genter and Herve Traineau Published Journal Journal of Volcanology and Geothermal...

  14. Geomechanical Fracturing with Flow and Heat

    Energy Science and Technology Software Center (OSTI)

    2009-01-01

    The GeoFracFH model is a particle-based discrete element model (DEM) that has been coupled with fluid flow and heat conduction/convection. In this model, the rock matrix material is represented by a network of DEM particles connected by mechanical bonds (elastic beams in this case, see Figure 1, gray particles connected by beams). During the simulation process, the mechanical bonds that have been stretched or bent beyond a critical strain (both tensile and shear failures aremore » simulated) are broken and removed from the network in a progressive manner. Bonds can be removed from the network with rates or probabilities that depend on their stress or strain, or the properties of the discrete elements and bonds can be varied continuously to represent phenomena such as creep, strain hardening, and chemical degradation. The coupling of a DEM geomechanical model with models for Darcy flow and heat transport is also illustrated in Figure 1. Darcy flow and heat transport equations are solved on an underlying fixed finite difference grid with evolving porosity and permeability for each grid cell that depends on the local structure of the discrete element network (such as the DEM particle density). The fluid pressure gradient exerts forces on individual elements of the DEM network, which then deforms and fractures the rock matrix. The deformation/fracturing in turn changes the permeability which again changes the evolution of fluid pressure, coupling the two phenomena. The intimate coupling between fracturing, fluid flow, and thermal transport makes the GeoFracFH model, rather than conventional continuum mechanical models, necessary for coupled hydro-thermal-mechanical problems in the subsurface.« less

  15. Statistical analysis of surface lineaments and fractures for characterizing naturally fractured reservoirs

    SciTech Connect (OSTI)

    Guo, Genliang; George, S.A.; Lindsey, R.P.

    1997-08-01

    Thirty-six sets of surface lineaments and fractures mapped from satellite images and/or aerial photos from parts of the Mid-continent and Colorado Plateau regions were collected, digitized, and statistically analyzed in order to obtain the probability distribution functions of natural fractures for characterizing naturally fractured reservoirs. The orientations and lengths of the surface linear features were calculated using the digitized coordinates of the two end points of each individual linear feature. The spacing data of the surface linear features within an individual set were, obtained using a new analytical sampling technique. Statistical analyses were then performed to find the best-fit probability distribution functions for the orientation, length, and spacing of each data set. Twenty-five hypothesized probability distribution functions were used to fit each data set. A chi-square goodness-of-fit test was used to rank the significance of each fit. A distribution which provides the lowest chi-square goodness-of-fit value was considered the best-fit distribution. The orientations of surface linear features were best-fitted by triangular, normal, or logistic distributions; the lengths were best-fitted by PearsonVI, PearsonV, lognormal2, or extreme-value distributions; and the spacing data were best-fitted by lognormal2, PearsonVI, or lognormal distributions. These probability functions can be used to stochastically characterize naturally fractured reservoirs.

  16. Effects of Fusion Zone Size and Failure Mode on Peak Load and Energy Absorption of Advanced High Strength Steel Spot Welds under Lap Shear Loading Conditions

    SciTech Connect (OSTI)

    Sun, Xin; Stephens, Elizabeth V.; Khaleel, Mohammad A.

    2008-06-01

    This paper examines the effects of fusion zone size on failure modes, static strength and energy absorption of resistance spot welds (RSW) of advanced high strength steels (AHSS) under lap shear loading condition. DP800 and TRIP800 spot welds are considered. The main failure modes for spot welds are nugget pullout and interfacial fracture. Partial interfacial fracture is also observed. Static weld strength tests using lap shear samples were performed on the joint populations with various fusion zone sizes. The resulted peak load and energy absorption levels associated with each failure mode were studied for all the weld populations using statistical data analysis tools. The results in this study show that AHSS spot welds with conventionally required fusion zone size of can not produce nugget pullout mode for both the DP800 and TRIP800 welds under lap shear loading. Moreover, failure mode has strong influence on weld peak load and energy absorption for all the DP800 welds and the TRIP800 small welds: welds failed in pullout mode have statistically higher strength and energy absorption than those failed in interfacial fracture mode. For TRIP800 welds above the critical fusion zone level, the influence of weld failure modes on peak load and energy absorption diminishes. Scatter plots of peak load and energy absorption versus weld fusion zone size were then constructed, and the results indicate that fusion zone size is the most critical factor in weld quality in terms of peak load and energy absorption for both DP800 and TRIP800 spot welds.

  17. Superconducting fault current-limiter with variable shunt impedance

    DOE Patents [OSTI]

    Llambes, Juan Carlos H; Xiong, Xuming

    2013-11-19

    A superconducting fault current-limiter is provided, including a superconducting element configured to resistively or inductively limit a fault current, and one or more variable-impedance shunts electrically coupled in parallel with the superconducting element. The variable-impedance shunt(s) is configured to present a first impedance during a superconducting state of the superconducting element and a second impedance during a normal resistive state of the superconducting element. The superconducting element transitions from the superconducting state to the normal resistive state responsive to the fault current, and responsive thereto, the variable-impedance shunt(s) transitions from the first to the second impedance. The second impedance of the variable-impedance shunt(s) is a lower impedance than the first impedance, which facilitates current flow through the variable-impedance shunt(s) during a recovery transition of the superconducting element from the normal resistive state to the superconducting state, and thus, facilitates recovery of the superconducting element under load.

  18. Material brittle fracture owing to thermoelastic effect of high energy nuclear particle

    SciTech Connect (OSTI)

    Kalinichenko, A.I.

    1996-12-31

    Rapid arising of the overheated domain near very heavy ion path (near fast neutron collision point) in solid results in generation of cylinder (spherical) thermoelastic stress wave. The latter can exceed the material strength and cause brittle fracture at going out on the free body interface. Size and shape of an erosion zone as well as erosion rate for both sorts of primary nuclear particles are found. The role of wave attenuation is discussed. The products of erosion are of macroscopic scaly particles having the typical thickness (1 {divided_by} 5) {center_dot} 10{sup -7} cm and mass 10{sup -18} {divided_by} 10{sup -17} g. Such ion (neutron)-stimulated thermoacoustic grinding can take place in radioactive materials with fissionable addenda. The consideration of the brittle destruction under cosmic ray bombardment may be essential for equipment of deep space missions.

  19. Treating tar sands formations with karsted zones

    DOE Patents [OSTI]

    Vinegar, Harold J.; Karanikas, John Michael

    2010-03-09

    Methods for treating a tar sands formation are described herein. The tar sands formation may have one or more karsted zones. Methods may include providing heat from one or more heaters to one or more karsted zones of the tar sands formation to mobilize fluids in the formation. At least some of the mobilized fluids may be produced from the formation.

  20. Fracture Toughness and Strength in a New Class of Bainitic Chromium-Tungsten Steels

    SciTech Connect (OSTI)

    Mao, S. X.; Sikka, V. K.

    2006-06-01

    This project dealt with developing an understanding of the toughening and stengthening mechanisms for a new class of Fe-3Cr-W(V) steels developed at Oak Ridge National Laboratory (ORNL) in collaboration with Nooter Corporation and other industrial partners. The new steele had 50% higher tensile strength up to 650 degrees Celsius than currently used steels and the potential for not requiring any postweld heat treatment (PWHT) and for reducing equipment weight by 25%. This project was closely related to the Nooter project described in the report Development of a New Class of Fe-3Cr-W(V) Ferritic steels for Industrial Process Applications (ORNL/TM-2005/82). The project was carried out jointly by the University of Pittsburgh and ORNL. The University of Pittsburgh carried out fracture toughness measurements and microstructural analysis on base metal and welded plates prepared at ORNL. The project focused on three areas. The first dealt with detailed microstructural analysis of base compositions of 3Cr-3WV and 3Cr-3WBV(Ta) in both normalized (N) and normalized and tempered (NT) conditions. The second aspect of the prject dealt with determining tensile properties and fracture toughness values of K{subIC} at room temperature for both 3Cr-3Wv and 3Cr-3WV(Ta) compositions. The third focus of the project was to measure the fracture toughness values of the base metal and the heat-affectged zone (HAZ) of a plate of Fe-3Cr-W(Mo)V steel plate welded by the gas tungsten are (GTA) process. The HAZ toughness was measured in both the as-welded and the PWHT condition.

  1. Measurement of fracture toughness by nanoindentation methods: Recent advances and future challenges

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Sebastiani, Marco; Johanns, K. E.; Herbert, Erik G.; Pharr, George M.

    2015-04-30

    In this study, we describe recent advances and developments for the measurement of fracture toughness at small scales by the use of nanoindentation-based methods including techniques based on micro-cantilever beam bending and micro-pillar splitting. A critical comparison of the techniques is made by testing a selected group of bulk and thin film materials. For pillar splitting, cohesive zone finite element simulations are used to validate a simple relationship between the critical load at failure, the pillar radius, and the fracture toughness for a range of material properties and coating/substrate combinations. The minimum pillar diameter required for nucleation and growth ofmore » a crack during indentation is also estimated. An analysis of pillar splitting for a film on a dissimilar substrate material shows that the critical load for splitting is relatively insensitive to the substrate compliance for a large range of material properties. Experimental results from a selected group of materials show good agreement between single cantilever and pillar splitting methods, while a discrepancy of ~25% is found between the pillar splitting technique and double-cantilever testing. It is concluded that both the micro-cantilever and pillar splitting techniques are valuable methods for micro-scale assessment of fracture toughness of brittle ceramics, provided the underlying assumptions can be validated. Although the pillar splitting method has some advantages because of the simplicity of sample preparation and testing, it is not applicable to most metals because their higher toughness prevents splitting, and in this case, micro-cantilever bend testing is preferred.« less

  2. Numerical simulation of gas flow through unsaturated fractured rock at Yucca Mountain, Nevada

    SciTech Connect (OSTI)

    Cooper, C.A.

    1990-01-01

    Numerical analysis is used to identify the physical phenomena associated with barometrically driven gas (air and water vapor) flow through unsaturated fractured rock at Yucca Mountain, Nevada. Results from simple finite difference simulations indicate that for a fractured rock scenario, the maximum velocity of air out of an uncased 10 cm borehole is 0.002 m s{sub {minus}1}. An equivalent porous medium (EPM) model was incorporated into a multiphase, multicomponent simulator to test more complex conceptual models. Results indicate that for a typical June day, a diurnal pressure wave propagates about 160 m into the surrounding Tiva Canyon hydrogeologic unit. Dry air that enters the formation evaporates water around the borehole which reduces capillary pressure. Multiphase countercurrent flow develops in the vicinity of the hole; the gas phase flows into the formation while the liquid phase flows toward the borehole. The effect occurs within 0.5 m of the borehole. The amount of water vapor leaving the formation during 1 day is 900 cm{sup 3}. This is less than 0.1% of the total recharge into the formation, suggesting that the barometric effect may be insignificant in drying the unsaturated zone. However, gas phase velocities out of the borehole (3 m s{sup {minus}1}), indicating that observed flow rates from wells along the east flank of Yucca Mountain were able to be simulated with a barometric model.

  3. Laboratory studies of radionuclide transport in fractured Climax granite

    SciTech Connect (OSTI)

    Failor, R.; Isherwood, D.; Raber, E.; Vandergraaf, T.

    1982-06-01

    This report documents our laboratory studies of radionuclide transport in fractured granite cores. To simulate natural conditions, our laboratory studies used naturally fractured cores and natural ground water from the Climax Granite Stock at the Nevada Test Site. For comparison, additional tests used artificially fractured granite cores or distilled water. Relative to the flow of tritiated water, {sup 85}Sr and /sup 95m/Tc showed little or no retardation, whereas {sup 137}Cs was retarded. After the transport runs the cores retained varying amounts of the injected radionuclides along the fracture. Autoradiography revealed some correlation between sorption and the fracture fill material. Strontium and cesium retention increased when the change was made from natural ground water to distilled water. Artificial fractures retained less {sup 137}Cs than most natural fractures. Estimated fracture apertures from 18 to 60 {mu}m and hydraulic conductivities from 1.7 to 26 x 10{sup -3} m/s were calculated from the core measurements.

  4. Analysis of three sets of SWIW tracer-test data using a two-population complex fracture model for matrix diffusion and sorption

    SciTech Connect (OSTI)

    Doughty, C.; Tsang, C.F.

    2009-08-01

    A complex fracture model employing two populations for diffusion and sorption is proposed to analyze three representative single-well injection-withdrawal (SWIW) tracer tests from Forsmark and Laxemar, the two sites under investigation by the Swedish Nuclear Fuel and Waste Management Company (SKB). One population represents the semi-infinite rock matrix and the other represents finite blocks that can become saturated, thereafter accepting no further diffusion or sorption. The diffusion and sorption parameters of the models are inferred by matching tracer breakthrough curves (BTCs). Three tracers are simultaneously injected, uranine (Ur), which is conservative, and rubidium (Rb) and cesium (Cs), which are non-conservative. For non-sorbing tracer uranine, the finite blocks become saturated with test duration of the order of 10 hours, and both the finite and the semi-infinite populations play a distinct role in controlling BTCs. For sorbing tracers Rb and Cs, finite blocks do not saturate, but act essentially as semi-infinite, and thus BTC behavior is comparable to that obtained for a model containing only a semi-infinite rock matrix. The ability to obtain good matches to BTCs for both sorbing and non-sorbing tracers for these three different SWIW data sets demonstrates that the two-population complex fracture model may be a useful conceptual model to analyze all SWIW tracer tests in fractured rock, and perhaps also usual multiwell tracer tests. One of the two populations should be semi-infinite rock matrix and the other finite blocks that can saturate. The latter can represent either rock blocks or gouge within the fracture, a fracture skin zone, or stagnation zones.

  5. Effects of Fusion Zone Size on Failure Modes and Performance of Advanced High Strength Steel Spot Welds

    SciTech Connect (OSTI)

    Sun, Xin; Stephens, Elizabeth V.; Khaleel, Mohammad A.

    2006-04-28

    This paper examines the effects of fusion zone size on failure modes, static strength and energy absorption of resistance spot welds (RSW) of advanced high strength steels (AHSS). DP800 and TRIP800 spot welds are considered. The main failure modes for spot welds are nugget pullout and interfacial fracture. Partial interfacial fracture is also observed. The critical fusion zone sizes to ensure nugget pull-out failure mode are developed for both DP800 and TRIP800 using the limit load based analytical model and the micro-hardness measurements of the weld cross sections. Static weld strength tests using cross tension samples were performed on the joint populations with controlled fusion zone sizes. The resulted peak load and energy absorption levels associated with each failure mode were studied using statistical data analysis tools. The results in this study show that the conventional weld size of 4 t can not produce nugget pullout mode for both the DP800 and TRIP800 materials. The results also suggest that performance based spot weld acceptance criteria should be developed for different AHSS spot welds.

  6. A Process and Environment Aware Sierra/SolidMechanics Cohesive Zone Modeling Capability for Polymer/Solid Interfaces

    SciTech Connect (OSTI)

    Reedy, E. D.; Chambers, Robert S.; Hughes, Lindsey Gloe; Kropka, Jamie Michael; Stavig, Mark E.; Stevens, Mark J.

    2015-09-01

    The performance and reliability of many mechanical and electrical components depend on the integrity of po lymer - to - solid interfaces . Such interfaces are found in adhesively bonded joints, encapsulated or underfilled electronic modules, protective coatings, and laminates. The work described herein was aimed at improving Sandia's finite element - based capability to predict interfacial crack growth by 1) using a high fidelity nonlinear viscoelastic material model for the adhesive in fracture simulations, and 2) developing and implementing a novel cohesive zone fracture model that generates a mode - mixity dependent toughness as a natural consequence of its formulation (i.e., generates the observed increase in interfacial toughness wi th increasing crack - tip interfacial shear). Furthermore, molecular dynamics simulations were used to study fundamental material/interfa cial physics so as to develop a fuller understanding of the connection between molecular structure and failure . Also reported are test results that quantify how joint strength and interfacial toughness vary with temperature.

  7. Laser notching ceramics for reliable fracture toughness testing

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Barth, Holly D.; Elmer, John W.; Freeman, Dennis C.; Schaefer, Ronald D.; Derkach, Oleg; Gallegos, Gilbert F.

    2015-09-19

    A new method for notching ceramics was developed using a picosecond laser for fracture toughness testing of alumina samples. The test geometry incorporated a single-edge-V-notch that was notched using picosecond laser micromachining. This method has been used in the past for cutting ceramics, and is known to remove material with little to no thermal effect on the surrounding material matrix. This study showed that laser-assisted-machining for fracture toughness testing of ceramics was reliable, quick, and cost effective. In order to assess the laser notched single-edge-V-notch beam method, fracture toughness results were compared to results from other more traditional methods, specificallymore » surface-crack in flexure and the chevron notch bend tests. Lastly, the results showed that picosecond laser notching produced precise notches in post-failure measurements, and that the measured fracture toughness results showed improved consistency compared to traditional fracture toughness methods.« less

  8. Laser notching ceramics for reliable fracture toughness testing

    SciTech Connect (OSTI)

    Barth, Holly D.; Elmer, John W.; Freeman, Dennis C.; Schaefer, Ronald D.; Derkach, Oleg; Gallegos, Gilbert F.

    2015-09-19

    A new method for notching ceramics was developed using a picosecond laser for fracture toughness testing of alumina samples. The test geometry incorporated a single-edge-V-notch that was notched using picosecond laser micromachining. This method has been used in the past for cutting ceramics, and is known to remove material with little to no thermal effect on the surrounding material matrix. This study showed that laser-assisted-machining for fracture toughness testing of ceramics was reliable, quick, and cost effective. In order to assess the laser notched single-edge-V-notch beam method, fracture toughness results were compared to results from other more traditional methods, specifically surface-crack in flexure and the chevron notch bend tests. Lastly, the results showed that picosecond laser notching produced precise notches in post-failure measurements, and that the measured fracture toughness results showed improved consistency compared to traditional fracture toughness methods.

  9. Evaluation and significance of fracture toughness in ceramic materials

    SciTech Connect (OSTI)

    Mutoh, Y.

    1995-12-31

    Fracture toughness tests of several ceramic materials were carried out according to the various test methods, that is the Bridge indentation (BI, SEPB), Fatigue precrack (FP), Controlled surface flaw (CSF), Chevron notch (CN) and Indentation fracture (IF) methods. Mutual comparison of the test results was made to discuss the validity and applicability of each test method. Significance of the apparent fracture toughness with stable crack growth was discussed. The intrinsic fracture toughness can be obtained by the CSF method, in which a small surface crack is used. At high temperatures, since nonlinear deformation due to softening of glass phase and stable crack growth occur, nonlinear fracture mechanics approach should be applied. J{sub IC}-value is successfully evaluated according to the R-curve method.

  10. Mobile machine hazardous working zone warning system

    DOE Patents [OSTI]

    Schiffbauer, W.H.; Ganoe, C.W.

    1999-08-17

    A warning system is provided for a mobile working machine to alert an individual of a potentially dangerous condition in the event the individual strays into a hazardous working zone of the machine. The warning system includes a transmitter mounted on the machine and operable to generate a uniform magnetic field projecting beyond an outer periphery of the machine in defining a hazardous working zone around the machine during operation. A receiver, carried by the individual and activated by the magnetic field, provides an alarm signal to alert the individual when he enters the hazardous working zone of the machine. 3 figs.

  11. Mobile machine hazardous working zone warning system

    DOE Patents [OSTI]

    Schiffbauer, William H.; Ganoe, Carl W.

    1999-01-01

    A warning system is provided for a mobile working machine to alert an individual of a potentially dangerous condition in the event the individual strays into a hazardous working zone of the machine. The warning system includes a transmitter mounted on the machine and operable to generate a uniform magnetic field projecting beyond an outer periphery of the machine in defining a hazardous working zone around the machine during operation thereof. A receiver, carried by the individual and activated by the magnetic field, provides an alarm signal to alert the individual when he enters the hazardous working zone of the machine.

  12. DOE - NNSA/NFO -- Kids Zone

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    ZONE NNSA/NFO Language Options U.S. DOE/NNSA - Nevada Field Office Cartoon drawing of science girl Kids Zone Welcome K-12 students and teachers! The NNSA/NFO Kids Zone contains information regarding the Nevada Regional Science Bowl, the Environmental Management Kids Display/Activity Book, Student Forum, and lots of photos. Teachers - You can also request a speaker for your classroom or school by filling out the Speakers Bureau Request Form. Feel free to browse the site and come back often as we

  13. Cluster-based architecture for fault-tolerant quantum computation (Journal

    Office of Scientific and Technical Information (OSTI)

    Article) | SciTech Connect Cluster-based architecture for fault-tolerant quantum computation Citation Details In-Document Search Title: Cluster-based architecture for fault-tolerant quantum computation We present a detailed description of an architecture for fault-tolerant quantum computation, which is based on the cluster model of encoded qubits. In this cluster-based architecture, concatenated computation is implemented in a quite different way from the usual circuit-based architecture

  14. Arc-Fault Detector Algorithm Evaluation Method Utilizing Prerecorded Arcing Signatures

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Arc-Fault Detector Algorithm Evaluation Method Utilizing Prerecorded Arcing Signatures Jay Johnson 1 and Jack Kang 2 1 Sandia National Laboratories, Albuquerque, NM, USA 2 Sensata Technologies, Attleboro, MA, USA ABSTRACT Abstract - The 2011 National Electrical Code® Article 690.11 requires photovoltaic systems on or penetrating a building to include a DC arc-fault protection device. In order to satisfy this requirement, new Arc-Fault Detectors (AFDs) are being developed by multiple

  15. Fracture toughness for copper oxide superconductors

    DOE Patents [OSTI]

    Goretta, K.C.; Kullberg, M.L.

    1993-04-13

    An oxide-based strengthening and toughening agent, such as tetragonal ZrO[sub 2] particles, has been added to copper oxide superconductors, such as superconducting YBa[sub 2]Cu[sub 3]O[sub x] (123) to improve its fracture toughness (K[sub IC]). A sol-gel coating which is non-reactive with the superconductor, such as Y[sub 2]BaCuO[sub 5] (211) on the ZrO[sub 2] particles minimized the deleterious reactions between the superconductor and the toughening agent dispersed therethrough. Addition of 20 mole percent ZrO[sub 2] coated with 211 yielded a 123 composite with a K[sub IC] of 4.5 MPa(m)[sup 0.5].

  16. Fracture toughness for copper oxide superconductors

    DOE Patents [OSTI]

    Goretta, Kenneth C.; Kullberg, Marc L.

    1993-01-01

    An oxide-based strengthening and toughening agent, such as tetragonal Zro.sub.2 particles, has been added to copper oxide superconductors, such as superconducting YBa.sub.2 Cu.sub.3 O.sub.x (123) to improve its fracture toughness (K.sub.IC). A sol-gel coating which is non-reactive with the superconductor, such as Y.sub.2 BaCuO.sub.5 (211) on the ZrO.sub.2 particles minimized the deleterious reactions between the superconductor and the toughening agent dispersed therethrough. Addition of 20 mole percent ZrO.sub.2 coated with 211 yielded a 123 composite with a K.sub.IC of 4.5 MPa(m).sup.0.5.

  17. Investigations of stacking fault density in perpendicular recording media

    SciTech Connect (OSTI)

    Piramanayagam, S. N. Varghese, Binni; Yang, Yi; Kiat Lee, Wee; Khume Tan, Hang

    2014-06-28

    In magnetic recording media, the grains or clusters reverse their magnetization over a range of reversal field, resulting in a switching field distribution. In order to achieve high areal densities, it is desirable to understand and minimize such a distribution. Clusters of grains which contain stacking faults (SF) or fcc phase have lower anisotropy, an order lower than those without them. It is believed that such low anisotropy regions reverse their magnetization at a much lower reversal field than the rest of the material with a larger anisotropy. Such clusters/grains cause recording performance deterioration, such as adjacent track erasure and dc noise. Therefore, the observation of clusters that reverse at very low reversal fields (nucleation sites, NS) could give information on the noise and the adjacent track erasure. Potentially, the observed clusters could also provide information on the SF. In this paper, we study the reversal of nucleation sites in granular perpendicular media based on a magnetic force microscope (MFM) methodology and validate the observations with high resolution cross-section transmission electron microscopy (HRTEM) measurements. Samples, wherein a high anisotropy CoPt layer was introduced to control the NS or SF in a systematic way, were evaluated by MFM, TEM, and magnetometry. The magnetic properties indicated that the thickness of the CoPt layer results in an increase of nucleation sites. TEM measurements indicated a correlation between the thickness of CoPt layer and the stacking fault density. A clear correlation was also observed between the MFM results, TEM observations, and the coercivity and nucleation field of the samples, validating the effectiveness of the proposed method in evaluating the nucleation sites which potentially arise from stacking faults.

  18. Novel Coupled Thermochronometric and Geochemical Investigation of Blind Geothermal Resources in Fault-Controlled Dilational Corners

    Broader source: Energy.gov [DOE]

    Novel Coupled Thermochronometric and Geochemical Investigation of Blind Geothermal Resources in Fault-Controlled Dilational Corners presentation at the April 2013 peer review meeting held in Denver, Colorado.

  19. Wind Power Plant Enhancement with a Fault-Current Limiter: Preprint

    SciTech Connect (OSTI)

    Muljadi, E.; Gevorgian, V.; DeLaRosa, F.

    2011-03-01

    This paper investigates the capability of a saturable core fault-current limiter to limit the short circuit current of different types of wind turbine generators.

  20. Non-abelian fractional quantum hall effect for fault-resistant...

    Office of Scientific and Technical Information (OSTI)

    Non-abelian fractional quantum hall effect for fault-resistant topological quantum computation. Citation Details In-Document Search Title: Non-abelian fractional quantum hall...

  1. Sandia Research on PV Arc-Fault Detection Submitted for US Patent

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Predictive Simulation of Engines Transportation Energy Consortiums Engine Combustion ... The 2011 National Electrical Code requires PV DC series arc-fault protection, but does ...

  2. A Fault Oblivious Extreme-Scale Execution Environment

    SciTech Connect (OSTI)

    McKie, Jim

    2014-11-20

    The FOX project, funded under the ASCR X-stack I program, developed systems software and runtime libraries for a new approach to the data and work distribution for massively parallel, fault oblivious application execution. Our work was motivated by the premise that exascale computing systems will provide a thousand-fold increase in parallelism and a proportional increase in failure rate relative to today’s machines. To deliver the capability of exascale hardware, the systems software must provide the infrastructure to support existing applications while simultaneously enabling efficient execution of new programming models that naturally express dynamic, adaptive, irregular computation; coupled simulations; and massive data analysis in a highly unreliable hardware environment with billions of threads of execution. Our OS research has prototyped new methods to provide efficient resource sharing, synchronization, and protection in a many-core compute node. We have experimented with alternative task/dataflow programming models and shown scalability in some cases to hundreds of thousands of cores. Much of our software is in active development through open source projects. Concepts from FOX are being pursued in next generation exascale operating systems. Our OS work focused on adaptive, application tailored OS services optimized for multi → many core processors. We developed a new operating system NIX that supports role-based allocation of cores to processes which was released to open source. We contributed to the IBM FusedOS project, which promoted the concept of latency-optimized and throughput-optimized cores. We built a task queue library based on distributed, fault tolerant key-value store and identified scaling issues. A second fault tolerant task parallel library was developed, based on the Linda tuple space model, that used low level interconnect primitives for optimized communication. We designed fault tolerance mechanisms for task parallel computations employing work stealing for load balancing that scaled to the largest existing supercomputers. Finally, we implemented the Elastic Building Blocks runtime, a library to manage object-oriented distributed software components. To support the research, we won two INCITE awards for time on Intrepid (BG/P) and Mira (BG/Q). Much of our work has had impact in the OS and runtime community through the ASCR Exascale OS/R workshop and report, leading to the research agenda of the Exascale OS/R program. Our project was, however, also affected by attrition of multiple PIs. While the PIs continued to participate and offer guidance as time permitted, losing these key individuals was unfortunate both for the project and for the DOE HPC community.

  3. Field Guide for Testing Existing Photovoltaic Systems for Ground Faults and Installing Equipment to Mitigate Fire Hazards: November 2012 - October 2013

    SciTech Connect (OSTI)

    Brooks, William

    2015-02-01

    Ground faults and arc faults are the two most common reasons for fires in photovoltaic (PV) arrays and methods exist that can mitigate the hazards. This report provides field procedures for testing PV arrays for ground faults, and for implementing high resolution ground fault and arc fault detectors in existing and new PV system designs.

  4. China-Low Carbon Development Zones | Open Energy Information

    Open Energy Info (EERE)

    China-Low Carbon Development Zones (Redirected from E3G-China-Low Carbon Development Zones) Jump to: navigation, search Name China-Low Carbon Development Zones AgencyCompany...

  5. Category:ASHRAE Climate Zones | Open Energy Information

    Open Energy Info (EERE)

    Category Edit History Category:ASHRAE Climate Zones Jump to: navigation, search Climate Zones defined in the ASHRAE 169-2006 standards. Pages in category "ASHRAE Climate Zones" The...

  6. Seismic waves in rocks with fluids and fractures

    SciTech Connect (OSTI)

    Berryman, J.G.

    2007-05-14

    Seismic wave propagation through the earth is often stronglyaffected by the presence of fractures. When these fractures are filledwith fluids (oil, gas, water, CO2, etc.), the type and state of the fluid(liquid or gas) can make a large difference in the response of theseismic waves. This paper summarizes recent work on methods ofdeconstructing the effects of fractures, and any fluids within thesefractures, on seismic wave propagation as observed in reflection seismicdata. One method explored here is Thomsen's weak anisotropy approximationfor wave moveout (since fractures often induce elastic anisotropy due tononuniform crack-orientation statistics). Another method makes use ofsome very convenient fracture parameters introduced previously thatpermit a relatively simple deconstruction of the elastic and wavepropagation behavior in terms of a small number of fracture parameters(whenever this is appropriate, as is certainly the case for small crackdensities). Then, the quantitative effects of fluids on thesecrack-influence parameters are shown to be directly related to Skempton scoefficient B of undrained poroelasticity (where B typically ranges from0 to 1). In particular, the rigorous result obtained for the low crackdensity limit is that the crack-influence parameters are multiplied by afactor (1 ? B) for undrained systems. It is also shown how fractureanisotropy affects Rayleigh wave speed, and how measured Rayleigh wavespeeds can be used to infer shear wave speed of the fractured medium.Higher crack density results are also presented by incorporating recentsimulation data on such cracked systems.

  7. Vadose Zone Transport Field Study: Status Report

    SciTech Connect (OSTI)

    Gee, Glendon W.; Ward, Anderson L.

    2001-11-30

    Studies were initiated at the Hanford Site to evaluate the process controlling the transport of fluids in the vadose zone and to develop a reliable database upon which vadose-zone transport models can be calibrated. These models are needed to evaluate contaminant migration through the vadose zone to underlying groundwaters at Hanford. A study site that had previously been extensively characterized using geophysical monitoring techniques was selected in the 200 E Area. Techniques used previously included neutron probe for water content, spectral gamma logging for radionuclide tracers, and gamma scattering for wet bulk density. Building on the characterization efforts of the past 20 years, the site was instrumented to facilitate the comparison of nine vadose-zone characterization methods: advanced tensiometers, neutron probe, electrical resistance tomography (ERT), high-resolution resistivity (HRR), electromagnetic induction imaging (EMI), cross-borehole radar (XBR), and cross-borehole seismic (XBS). Soil coring was used to obtain soil samples for analyzing ionic and isotopic tracers.

  8. Climate Zone 5C | Open Energy Information

    Open Energy Info (EERE)

    C. Climate Zone 5C is defined as Marine with IP Units 5400 < HDD65F 7200 and SI Units 3000 < HDD18C 4000 . The following places are categorized as class 5C...

  9. Local Option- Rural Renewable Energy Development Zones

    Broader source: Energy.gov [DOE]

    Commercial renewable energy property in these zones are eligible for a 3 to 5 year local property tax exemption. Eligible property includes either wind, geothermal, solar, biomass, or other uncon...

  10. Marginal Ice Zone Observations and Processes Experiment

    Office of Scientific and Technical Information (OSTI)

    46 Investigations of Spatial and Temporal Variability of Ocean and Ice Conditions in and Near the Marginal Ice Zone: The "Marginal Ice Zone Observations and Processes Experiment" (MIZOPEX) Final Campaign Summary JA Maslanik February 2016 CLIMATE RESEARCH FACILITY DISCLAIMER This report was prepared as an account of work sponsored by the U.S. Government. Neither the United States nor any agency thereof, nor any of their employees, makes any warranty, express or implied, or assumes any

  11. Zone heated diesel particulate filter electrical connection

    DOE Patents [OSTI]

    Gonze, Eugene V.; Paratore, Jr., Michael J.

    2010-03-30

    An electrical connection system for a particulate filter is provided. The system includes: a particulate filter (PF) disposed within an outer shell wherein the PF is segmented into a plurality of heating zones; an outer mat disposed between the particulate filter and the outer shell; an electrical connector coupled to the outer shell of the PF; and a plurality of printed circuit connections that extend along the outer surface of the PF from the electrical connector to the plurality of heating zones.

  12. Treating nahcolite containing formations and saline zones

    DOE Patents [OSTI]

    Vinegar, Harold J

    2013-06-11

    A method for treating a nahcolite containing subsurface formation includes removing water from a saline zone in or near the formation. The removed water is heated using a steam and electricity cogeneration facility. The heated water is provided to the nahcolite containing formation. A fluid is produced from the nahcolite containing formation. The fluid includes at least some dissolved nahcolite. At least some of the fluid is provided to the saline zone.

  13. Coordinated Fault-Tolerance for High-Performance Computing Final Project Report

    SciTech Connect (OSTI)

    Panda, Dhabaleswar Kumar; Beckman, Pete

    2011-07-28

    With the Coordinated Infrastructure for Fault Tolerance Systems (CIFTS, as the original project came to be called) project, our aim has been to understand and tackle the following broad research questions, the answers to which will help the HEC community analyze and shape the direction of research in the field of fault tolerance and resiliency on future high-end leadership systems. Will availability of global fault information, obtained by fault information exchange between the different HEC software on a system, allow individual system software to better detect, diagnose, and adaptively respond to faults? If fault-awareness is raised throughout the system through fault information exchange, is it possible to get all system software working together to provide a more comprehensive end-to-end fault management on the system? #15; What are the missing fault-tolerance features that widely used HEC system software lacks today that would inhibit such software from taking advantage of systemwide global fault information? #15; What are the practical limitations of a systemwide approach for end-to-end fault management based on fault awareness and coordination? #15; What mechanisms, tools, and technologies are needed to bring about fault awareness and coordination of responses on a leadership-class system? #15; What standards, outreach, and community interaction are needed for adoption of the concept of fault awareness and coordination for fault management on future systems? Keeping our overall objectives in mind, the CIFTS team has taken a parallel fourfold approach. #15; Our central goal was to design and implement a light-weight, scalable infrastructure with a simple, standardized interface to allow communication of fault-related information through the system and facilitate coordinated responses. This work led to the development of the Fault Tolerance Backplane (FTB) publish-subscribe API specification, together with a reference implementation and several experimental implementations on top of existing publish-subscribe tools. #15; We enhanced the intrinsic fault tolerance capabilities representative implementations of a variety of key HPC software subsystems and integrated them with the FTB. Targeting software subsystems included: MPI communication libraries, checkpoint/restart libraries, resource managers and job schedulers, and system monitoring tools. #15; Leveraging the aforementioned infrastructure, as well as developing and utilizing additional tools, we have examined issues associated with expanded, end-to-end fault response from both system and application viewpoints. From the standpoint of system operations, we have investigated log and root cause analysis, anomaly detection and fault prediction, and generalized notification mechanisms. Our applications work has included libraries for fault-tolerance linear algebra, application frameworks for coupled multiphysics applications, and external frameworks to support the monitoring and response for general applications. #15; Our final goal was to engage the high-end computing community to increase awareness of tools and issues around coordinated end-to-end fault management.

  14. Using Chemicals to Optimize Conformance Control in Fractured Reservoirs

    SciTech Connect (OSTI)

    Seright, Randall S.; Liang, Jenn-Tai; Schrader, Richard; Hagstrom II, John; Wang, Ying; Kumar, Ananad; Wavrik, Kathryn

    2001-10-29

    This report describes work performed during the third and final year of the project, Using Chemicals to Optimize Conformance Control in Fractured Reservoirs. This research project had three objectives. The first objective was to develop a capability to predict and optimize the ability of gels to reduce permeability to water more than that to oil or gas. The second objective was to develop procedures for optimizing blocking agent placement in wells where hydraulic fractures cause channeling problems. The third objective was to develop procedures to optimize blocking agent placement in naturally fractured reservoirs.

  15. Haleakala SW Rift Zone Exploration | Open Energy Information

    Open Energy Info (EERE)

    SW Rift Zone Exploration Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Development Project: Haleakala SW Rift Zone Exploration Project Location Information...

  16. Bernalillo County, New Mexico ASHRAE 169-2006 Climate Zone |...

    Open Energy Info (EERE)

    Bernalillo County, New Mexico ASHRAE 169-2006 Climate Zone Jump to: navigation, search County Climate Zone Place Bernalillo County, New Mexico ASHRAE Standard ASHRAE 169-2006...

  17. Turkey Near-Zero Zone | Department of Energy

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    Corporation and the State Department, developed the Near-Zero Zone (NZZ) - an industrial energy efficiency project at the Ataturk Organized Industrial Zone in Izmir, Turkey. ...

  18. Adams County, Pennsylvania ASHRAE 169-2006 Climate Zone | Open...

    Open Energy Info (EERE)

    Adams County, Pennsylvania ASHRAE 169-2006 Climate Zone Jump to: navigation, search County Climate Zone Place Adams County, Pennsylvania ASHRAE Standard ASHRAE 169-2006 Climate...

  19. An Updated Site Scale Saturated Zone Ground Water Transport Model...

    Office of Scientific and Technical Information (OSTI)

    An Updated Site Scale Saturated Zone Ground Water Transport Model for Yucca Mountain. Citation Details In-Document Search Title: An Updated Site Scale Saturated Zone Ground Water ...

  20. Androscoggin County, Maine ASHRAE 169-2006 Climate Zone | Open...

    Open Energy Info (EERE)

    Apps Datasets Community Login | Sign Up Search Page Edit History Androscoggin County, Maine ASHRAE 169-2006 Climate Zone Jump to: navigation, search County Climate Zone Place...