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1

The effect of fractures, faults, and sheared shale zones on the hydrology of Bear Creek Burial Grounds A-South, Oak Ridge, Tennessee  

E-Print Network (OSTI)

Previous hydrologic models of flow in Bear Creek Valley have presented lateral flow as occurring through the Nolichucky Shale in parallel to strike fractures within thin carbonate beds; the effects of faults were not considered. This study presents a ground water flow model that incorporates lateral flow through parallel-to-strike fractures and thrust faults, and perpendicular-to-strike cross valley strike-slip faults. These latter cross-valley structures cause flow to be diverted to other strikeparallel zones of enhanced permeability towards the south side of the valley. Using core, geophysical and hydrologic data from five boreholes in the Bear Creek Burial Grounds three types of potential fluid-flow conduits were identified: fractures, faults, and shale shear zones. Open fractures decrease in abundance with depth and tend to occur most frequently in oolitic limestone beds relative to other carbonate lithologies. Fractures below 1 00 ft BGS in the Nolichucky Shale and below 250 ft in the Maynardville Limestone do not appear to be caused by dissolution; instead, they appear to be the result of a change in the local stress field due to erosion effects. Faults, both cross-valley and thrust faults, and sheared shale zones are interpreted to disrupt the lateral continuity of the bedding and increase the rock-mass permeability of the Nolichucky Shale, permitting ground water to flow these structural zones. This study provided opportunity to interpret DNAPL migration patterns from Burial Ground A-South. DNAPL migration parallel to the valley's axis is affected by parallel-to-strike fractures and thrust faults, and its lateral migration perpendicular to strike is influenced by cross valley strike-slip faults and decreasing collect at depth because of decreasing fracture occurrence and reduced permeability and then migrate laterally along the cross valley strike-slip faults until it encounters and enters a zone of higher permeability parallel to strike.

Hollon, Dwight Mitchell

1997-01-01T23:59:59.000Z

2

Stress and fault rock controls on fault zone hydrology, Coso geothermal  

Open Energy Info (EERE)

source source History View New Pages Recent Changes All Special Pages Semantic Search/Querying Get Involved Help Apps Datasets Community Login | Sign Up Search Page Edit History Facebook icon Twitter icon » Stress and fault rock controls on fault zone hydrology, Coso geothermal field, CA Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Conference Proceedings: Stress and fault rock controls on fault zone hydrology, Coso geothermal field, CA Details Activities (1) Areas (1) Regions (0) Abstract: In crystalline rock of the Coso Geothermal Field, CA, fractures are the primary source of permeability. At reservoir depths, borehole image, temperature, and mud logs indicate fluid flow is concentrated in extensively fractured damage zones of large faults well-oriented for slip.

3

Structural geology of Shawneetown fault zone, Southeastern Illinois  

SciTech Connect

Vertical movements of crustal blocks along the narrow east-west-trending Shawneetown fault zone in southeastern Illinois occurred between Early Permian and Late Cretaceous. The main blocks moved vertically and retured to roughly their orignal positions so that strata now show little relative offset across the fault zone. However, individual faults with displacements up to 3,500 ft (1,070 m) bound narrow slices of steeply tilted or overturned strata resulting in a juxtaposition of Kinderhookian (Lower Mississippian) and Upper Devonian strata with Lower Pennsylvanina strata. The bedrock is intensely fractured, commonly brecciated, and cemented with either silica or calcite. Slickensides and mullion display various orientations within the zone and on individual outcrops. The dominant movement, however, appears to be vertical with no evidence for significant strike-slip movements. Pleistocene deposits do not exhibit offsets across the fault zone, indicating that no tectonic activity has occurred since the beginning of that epoch. The trend of the fault zone changes abruptly from east-west in southern Gallatin and easternmost Saline Counties to south-southwest in southern Saline and northeastern Pope Counties, where it joins the Fluorspar area fault complex. Here the zone widens and develops a braided pattern as the amount of displacement along individual faults decreases. The Shawneetown fault zone and Flourspar area fault complex in part are younger than the Cottage Grove fault system to the northwest and the Wabash Valley fault system to the north. The hope of finding structural traps near the junctions of the fuel systems has spurred recent oil exploration in the area.

Lumm, D.K.; Nelson, W.J.

1983-09-01T23:59:59.000Z

4

Development of Characterization Technology for Fault Zone Hydrology  

SciTech Connect

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.

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

2010-08-06T23:59:59.000Z

5

Locating an active fault zone in Coso geothermal field by analyzing seismic  

Open Energy Info (EERE)

Locating an active fault zone in Coso geothermal field by analyzing seismic Locating an active fault zone in Coso geothermal field by analyzing seismic guided waves from microearthquake data Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Conference Proceedings: Locating an active fault zone in Coso geothermal field by analyzing seismic guided waves from microearthquake data Details Activities (1) Areas (1) Regions (0) Abstract: Active fault systems usually provide high-permeability channels for hydrothermal outflow in geothermal fields. Locating such fault systems is of a vital importance to plan geothermal production and injection drilling, since an active fault zone often acts as a fracture-extensive low-velocity wave guide to seismic waves. We have located an active fault zone in the Coso geothermal field, California, by identifying and analyzing

6

Faulting, fracturing, and sealing in foreland thrust belts: Examples from the subalpine chains  

SciTech Connect

The hydrocarbon potential of foreland thrust belts arises from source and reservoir rocks juxtaposed by the movement of thrust sheets, promoting maturation by loading and generating structural traps. Deformation in thrust belts can be localized on fault zones or distributed throughout thrust sheets; different deformation mechanisms operate to increase and decrease permeability. Migration and reservoir properties may be enhanced or reduced by faulting and fault-related deformation. These processes are examined in detail using examples from the northwest subalpine chains of France, a fold-and-thrust belt of well-differentiated Mesozoic shales and carbonates. Seeps of bitumen in foreland basin sediments indicate some migration of hydrocarbons along faults linking probable source and reservoir areas. Detailed examination of fault rocks and thrust sheets shows that fracture formation is an important strain mechanism which has the potential to form regions of enhanced permeability in structures such as hanging wall anticlines. However, the fractures observed are in general recemented, forming with crack-seal crystal growth. The faults themselves are complex zones up to tens of meters thick of subparallel anastomosing gouge, fractures, stylolites, and crystalline calcite, indicating synchronous cataclasis and pressure solution. The range of scales of fracturing suggests stick-slip (microseismic) fault activity. Permeability of the fault zones is enhanced during seismic fault slip and is otherwise steadily decreased by pressure solution and calcite deposition. The available migration pathways, and hence the location of potential reservoirs, is controlled by the timing, mechanisms, and extent of fault activity in this common and productive tectonic regime.

Bowler, S.; Butler, R.W.H.

1988-08-01T23:59:59.000Z

7

Transport of Bottom Water in the Romanche Fracture Zone and the Chain Fracture Zone  

Science Conference Proceedings (OSTI)

Two moored arrays deployed in the Romanche Fracture Zone and Chain Fracture Zone in the equatorial Atlantic Ocean provide two-year-long time series of current and temperature in the Lower North Atlantic Deep Water and the Antarctic Bottom Water. ...

Herlé Mercier; Kevin G. Speer

1998-05-01T23:59:59.000Z

8

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

Open Energy Info (EERE)

Thermal Waters Along The Konocti Bay Fault Zone, Lake County, California- A Re-Evaluation Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Journal Article: Thermal...

9

Mixing in the Romanche Fracture Zone  

Science Conference Proceedings (OSTI)

The Romanche Fracture Zone is a major gap in the Mid-Atlantic Ridge at the equator, which is deep enough to allow significant eastward flows of Antarctic Bottom Water from the Brazil Basin to the Sierra Leone and Guinea Abyssal Plains. While ...

Bruno Ferron; Herlé Mercier; Kevin Speer; Ann Gargett; Kurt Polzin

1998-10-01T23:59:59.000Z

10

Variation in sericite composition from fracture zones within...  

Open Energy Info (EERE)

zones of the crystalline basement contain coarse-grained relict muscovite, whereas rock alteration near fracture zones at temperatures > 150C is characterized by abundant...

11

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

Open Energy Info (EERE)

often function as hydrologic barriers separating regions of distinct fluid inclusion chemistry and temperature gradient. Distributed fracture networks play only a minor role in...

12

Development of Hydrologic Characterization Technology of Fault Zones  

E-Print Network (OSTI)

one example being Dixie Valley, Nevada, an active normalrock at various sites: Dixie Valley, Nevada; Wasatch, Utah;20 m in parts of the Dixie Valley and Wasatch fault zones.

Karasaki, Kenzi

2009-01-01T23:59:59.000Z

13

Locating an active fault zone in Coso geothermal field by analyzing seismic guided waves from microearthquake data  

DOE Green Energy (OSTI)

Active fault systems usually provide high-permeability channels for hydrothermal outflow in geothermal fields. Locating such fault systems is of a vital importance to plan geothermal production and injection drilling, since an active fault zone often acts as a fracture-extensive low-velocity wave guide to seismic waves. We have located an active fault zone in the Coso geothermal field, California, by identifying and analyzing a fault-zone trapped Rayleigh-type guided wave from microearthquake data. The wavelet transform is employed to characterize guided-wave's velocity-frequency dispersion, and numerical methods are used to simulate the guided-wave propagation. The modeling calculation suggests that the fault zone is {approx} 200m wide, and has a P wave velocity of 4.80 km/s and a S wave velocity of 3.00 km/s, which is sandwiched between two half spaces with relatively higher velocities (P wave velocity 5.60 km/s, and S wave velocity 3.20 km/s). zones having vertical or nearly vertical dipping fault planes.

SGP-TR-150-16

1995-01-26T23:59:59.000Z

14

Surface and subsurface fault and fracture systems with associated natural gas production in the Lower Mississippian and Upper Devonian, Price Formation, southern West Virginia.  

E-Print Network (OSTI)

??Production from natural gas deposits is often enhanced by fault and fracture systems associated with reservoirs. This study presents analyses of fault and fracture systems… (more)

Johnson, S. Reed.

2007-01-01T23:59:59.000Z

15

Fracture characteristics and their relationships to producing zones in deep  

Open Energy Info (EERE)

source source History View New Pages Recent Changes All Special Pages Semantic Search/Querying Get Involved Help Apps Datasets Community Login | Sign Up Search Page Edit History Facebook icon Twitter icon » Fracture characteristics and their relationships to producing zones in deep wells, Raft River geothermal area Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Book: Fracture characteristics and their relationships to producing zones in deep wells, Raft River geothermal area Details Activities (1) Areas (1) Regions (0) Abstract: Fracture characteristics in the sedimentary and metamorphic rocks in the Raft River KGRA of Idaho are analyzed using geological, hydrological and borehole geophysical data from five deep geothermal production wells. Particular emphasis is placed on fracture identification using borehole

16

Modeling fault-zone guided waves of microearthquakes in a geothermal  

Open Energy Info (EERE)

fault-zone guided waves of microearthquakes in a geothermal fault-zone guided waves of microearthquakes in a geothermal reservoir Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Journal Article: Modeling fault-zone guided waves of microearthquakes in a geothermal reservoir Details Activities (1) Areas (1) Regions (0) Abstract: Fault-zone guided waves have been identified in microearthquake seismograms recorded at the Coso Geothermal Field, California. The observed guided waves have particle motions and propagation group velocities similar to Rayleigh wave modes. A numerical method has been employed to simulate the guided-wave propagation through the fault zone. By comparing observed and synthetic waveforms the fault-zone width and its P- and S-wave velocity structure have been estimated. It is suggested here that the identification

17

Evolution of the Sorong fault zone, northeast Indonesia  

SciTech Connect

The Sorong fault zone (SFZ) of northeast Indonesia is a broad zone of inferred left-lateral shear at the triple junction of the Indo-Australian, Eurasian, and Pacific plates. It is widely believed that fragments of the northern Australian continental margin in New Guinea are being detached and translated westward in this shear zone until they collide with the eastern margin of Eurasia (Sundaland) in the region of Sulawesi Island. However, the details of terrane translation, amalgamation, and docking remain poorly documented. In particular, the timing of events is very poorly constrained, with estimates for the commencement of the SFZ ranging from early Miocene or older to Pleistocene. Recent investigations of the SFZ and the adjacent regions of Sulawesi and Irian Jaya (Indonesian New Guinea), including new fieldwork in several of the SFZ island-terranes (Waigeo, Halmahera, Bacon, Obi, and Sula), suggest a less mobilist interpretation of the region than previous reconstructions. In general, the closest interisland geological correlations are between the geographically closest islands. This would seem to favor rather conservative reconstructions, and a new interpretation of the region based on this tenet is proposed. Although arc-continent collision commented in New Guinea during the mid-Oligocene and only slightly later in Sulaswesi, the SFZ did not begin to develop in its present form before the late Miocene.

Charlton, T.R.

1991-03-01T23:59:59.000Z

18

Development of Hydrologic Characterization Technology of Fault Zones  

E-Print Network (OSTI)

pathways in the Monterey Formation, California: Americanalong faults in the Monterey Formation, coastal California.

Karasaki, Kenzi

2009-01-01T23:59:59.000Z

19

Development of Hydrologic Characterization Technology of Fault Zones  

E-Print Network (OSTI)

modeling fluid and heat flow in fractured porous media, Soc.fluid flow, multicomponent transport, and heat transfer in porous and fractured media,fluid flow, solute transport, and heat transfer occur in porous and fractured media.

Karasaki, Kenzi

2009-01-01T23:59:59.000Z

20

Development of Hydrologic Characterization Technology of Fault Zones  

E-Print Network (OSTI)

and radiation in a multiphase, multicomponent, porous mediumin modeling multiphase flow in porous and fractured media,phase and multiphase non-Darcy flow in porous and fractured

Karasaki, Kenzi

2009-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "fracture zones faults" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


21

Thermal Waters Along The Konocti Bay Fault Zone, Lake County, California- A  

Open Energy Info (EERE)

Waters Along The Konocti Bay Fault Zone, Lake County, California- A Waters Along The Konocti Bay Fault Zone, Lake County, California- A Re-Evaluation Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Journal Article: Thermal Waters Along The Konocti Bay Fault Zone, Lake County, California- A Re-Evaluation Details Activities (3) Areas (1) Regions (0) Abstract: The Konocti Bay fault zone (KBFZ), initially regarded by some as a promising target for liquid-dominated geothermal systems, has been a disappointment. At least five exploratory wells were drilled in the vicinity of the KBFZ, but none were successful. Although the Na-K-Ca and Na-Li geothermometers indicate that the thermal waters discharging in the vicinity of Howard and Seigler Springs may have equilibrated at temperatures greater than 200°C, the spring temperatures and fluid

22

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

Open Energy Info (EERE)

Pull-Apart in Strike-Slip Fault Zone Pull-Apart in Strike-Slip Fault Zone Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Print PDF Pull-Apart in Strike-Slip Fault Zone Dictionary.png Pull-Apart in Strike-Slip Fault Zone: No definition has been provided for this term. Add a Definition Pull-aparts form in strike-slip fault zones. Arrows indicate direction of slip. (reference: http://myweb.cwpost.liu.edu/vdivener/notes/cont_transform.htm) Faulds uses this term as a structural control found in the Basin and Range province of the US. 4% of all Great Basin geothermal systems are located in pull-aparts but are more abundant within or along the margins of the Walker Lane. (reference: http://www.atlasgeoinc.com/wp-content/uploads/GRC2011-Faulds.pdf). Retrieved from "http://en.openei.org/w/index.php?title=Pull-Apart_in_Strike-Slip_Fault_Zone&oldid=599541"

23

Analysis of the growth of strike-slip faults using effective medium theory  

SciTech Connect

Increases in the dimensions of strike-slip faults including fault length, thickness of fault rock and the surrounding damage zone collectively provide quantitative definition of fault growth and are commonly measured in terms of the maximum fault slip. The field observations indicate that a common mechanism for fault growth in the brittle upper crust is fault lengthening by linkage and coalescence of neighboring fault segments or strands, and fault rock-zone widening into highly fractured inner damage zone via cataclastic deformation. The most important underlying mechanical reason in both cases is prior weakening of the rocks surrounding a fault's core and between neighboring fault segments by faulting-related fractures. In this paper, using field observations together with effective medium models, we analyze the reduction in the effective elastic properties of rock in terms of density of the fault-related brittle fractures and fracture intersection angles controlled primarily by the splay angles. Fracture densities or equivalent fracture spacing values corresponding to the vanishing Young's, shear, and quasi-pure shear moduli were obtained by extrapolation from the calculated range of these parameters. The fracture densities or the equivalent spacing values obtained using this method compare well with the field data measured along scan lines across the faults in the study area. These findings should be helpful for a better understanding of the fracture density/spacing distribution around faults and the transition from discrete fracturing to cataclastic deformation associated with fault growth and the related instabilities.

Aydin, A.; Berryman, J.G.

2009-10-15T23:59:59.000Z

24

Apex or Salient of Normal Fault | Open Energy Information  

Open Energy Info (EERE)

Apex or Salient of Normal Fault Apex or Salient of Normal Fault Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Print PDF Apex or Salient of Normal Fault Dictionary.png Apex or Salient of Normal Fault: Normal faults may intersect in the subsurface to form a fault apex or salient. Apices or salients of normal faults account for 3% of structural controls in the Great Basin. Other definitions:Wikipedia Reegle Controlling Structures List of controlling structures typically associated with geothermal systems: Major Normal Fault Termination of a Major Normal Fault Stepover or Relay Ramp in Normal Fault Zones Apex or Salient of Normal Fault Fault Intersection Accommodation Zone Displacement Transfer Zone Pull-Apart in Strike-Slip Fault Zone Intrusion Margins and Associated Fractures Stratigraphic Boundaries

25

Fault-zone seals in siliciclastic strata of the Columbus Basin, offshore Trinidad  

Science Conference Proceedings (OSTI)

This study combines observations from outcrop and drill core with an analysis of the hydrocarbon distribution in two mature oil and gas fields to document the factors controlling the existence of fault seals in the Tertiary sandstone-shale sequence of the Columbus Basin. Juxtaposition of reservoir sandstones against shale intervals across normal faults cannot explain the oil and gas distribution in this area, indicating that fault zones serve as the lateral seals for these hydrocarbon accumulations. The fault-zone seals for the largest hydrocarbon columns (50-200 m) consist of shale smears formed by ductile deformation of shale beds during fault slip. Fault segments that do not meet the criteria for development of a shale smear appear to be transmissible or can seal only small columns (shale smears are discontinuous, such as where a sandstone body is partially juxtaposed against itself, column heights are cross-fault spill-point limited and can be analyzed using fault-plane sections combined with mapping of shale-smear continuity. These traps are likely to preferentially spill high-density hydrocarbons once trap capacity is reached. In contrast, traps bounded by spatially continuous shale smears probably leak through the pore network of the fault-zone material at the top of the trap, thus favoring preferential movement of low-density hydrocarbons in a two-phase system. Hydrocarbon migration through stratigraphic sections containing fault-sealed traps of these two types may result in geochemical fractionation and phase segregation, both of which are observed in the Columbus Basin fields.

Gibson, R.G. [Amoco Production Research, Tulsa, OK (United States)

1994-09-01T23:59:59.000Z

26

Fault Intersection | Open Energy Information  

Open Energy Info (EERE)

source source History View New Pages Recent Changes All Special Pages Semantic Search/Querying Get Involved Help Apps Datasets Community Login | Sign Up Search Page Edit History Facebook icon Twitter icon » Fault Intersection Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Print PDF Fault Intersection Dictionary.png Fault Intersection: Fault intersections are junctions between normal faults and either transversely oriented strike-slip or oblique-slip faults. Subsurface fluid flow in these areas is enhanced by multiple minor faults that connect the major intersecting structures, forming highly fractured zones or dilational quadrants with increased permeability. Other definitions:Wikipedia Reegle Controlling Structures List of controlling structures typically associated with geothermal

27

Intrusion Margins and Associated Fractures | Open Energy Information  

Open Energy Info (EERE)

Intrusion Margins and Associated Fractures Intrusion Margins and Associated Fractures Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Print PDF Intrusion Margins and Associated Fractures Dictionary.png Intrusion Margins and Associated Fractures: No definition has been provided for this term. Add a Definition Controlling Structures List of controlling structures typically associated with geothermal systems: Major Normal Fault Termination of a Major Normal Fault Stepover or Relay Ramp in Normal Fault Zones Apex or Salient of Normal Fault Fault Intersection Accommodation Zone Displacement Transfer Zone Pull-Apart in Strike-Slip Fault Zone Intrusion Margins and Associated Fractures Stratigraphic Boundaries Fissure Swarms Caldera Rim Margins Lithologically Controlled Fractures caused by igneous activity creates permeability, allowing water

28

Variation in sericite composition from fracture zones within the Coso Hot  

Open Energy Info (EERE)

Variation in sericite composition from fracture zones within the Coso Hot Variation in sericite composition from fracture zones within the Coso Hot Sprints geothermal system Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Journal Article: Variation in sericite composition from fracture zones within the Coso Hot Sprints geothermal system Details Activities (1) Areas (1) Regions (0) Abstract: Two types of white micas are 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 rock alteration near fracture zones at temperatures > 150°C is characterized by abundant finegrained sericite in association with secondary calcite and quartz and unaltered relict microcline. In this hydrothermal sericite there

29

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

Science Conference Proceedings (OSTI)

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.

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

2009-03-31T23:59:59.000Z

30

Fracture process zone : microstructure and nanomechanics in quasi-brittle materials  

E-Print Network (OSTI)

Cracks begin (and end) at a crack tip; the "Fracture Process Zone" (FPZ) is a region of damage around the crack tip. The context of this research is the FPZ in quasi-brittle materials, which is characterized by cracking ...

Brooks, Zenzile (Zenzile Z.)

2013-01-01T23:59:59.000Z

31

Multi-offset vertical seismic profiles: fracture and fault identification for Appalachian basin reservoirs - two case examples  

SciTech Connect

Many Appalachian basin reservoirs occur in older rocks that are commonly fractured and faulted. These fractures and faults very often act as the reservoir trapping mechanism, especially in lithologies with no log-detectable matrix porosity. Traditional logging techniques, although possibly showing fault or fracture presence in the well bore, seldom provide clues to the extent of fracturing or location of nearby faults. Surface seismic data should show faults and perhaps even fracturing, but showing these features is often not possible in rugged terrain or in areas with thick coverings of unconsolidated surface material. Traditional seismic also has resolutions lower than that needed to detect small faults (less than 70 ft). Two case examples are shown from the northern Appalachian basin. The first example utilizes Schlumberger's slim hole seismic tool in cased holes in an area of thick unconsolidated glacial material along the Bass Island trend of western New York. The second example utilizes Schlumberger's SAT tool in an open-hole environment in an area of northwestern Pennsylvania with disturbed surface bedding and poor conventional surface seismic returns. The slim hole tool provides good data but with only slightly greater resolution than surface Vibroseis data. The SAT tool provides excellent resolution (down to 25 ft) in highly disturbed bedding.

Wyatt, D.E.; Bennett, B.A.; Walsh, J.J.

1988-08-01T23:59:59.000Z

32

Trapping capacity of fault zones, downdip Yegua Formation, Texas Gulf Coast basin  

E-Print Network (OSTI)

The homogenization of sediment from shearing forms traps in both the hanging wall and footwall due to capillary pressure differences. The sheared zone associated with large faults can form traps. Sheared zones associated with small faults can compartmentalize reservoirs leading to unreliable estimates of reserves. Measured values of capillary pressure were compared with estimated capillary pressure values from four correlation methods. Based on comparison of estimated pressure with measured pressure, Pittman's method gave the most reliable results for predicting capillary pressure and therefore the height of the oil column. However, all methods for predicting capillary pressure worked well for samples with porosities above 20% and permeabilities above 100 md. Hydrocarbon column heights were then determined from the capillary pressure values. The large sheared zone of the Cities Service Dincans1 (CD1) well, Toro Grande field, Jackson County, has a predicted trapping capacity of up to 1,961 ft of oil at 10,000 ft depth and 35% saturation of oil. Shearing is mostly at the hand specimen scale in the General Crude Kirby Lumber 2 (GCK2) well, East Sour Lake field, Hardin County, which has a maximum trapping capacity of 111 ft. From this study, it is then concluded that a homogenized sheared zone, formed from ductile deformation of sand and shale layers can form a trap to hydrocarbons. Sheared zones may be thick zones, on the order of feet, or smaller zones at microscopic or hand specimen scale. The larger the sheared zone is, the greater the trapping capacity of the fault.

Hintz, Jena Christine

2001-01-01T23:59:59.000Z

33

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

Science Conference Proceedings (OSTI)

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.

Stephen L. Karner, Ph.D

2006-06-01T23:59:59.000Z

34

Internal structure of the Kern Canyon Fault, California: a deeply exhumed strike-slip fault  

E-Print Network (OSTI)

Deformation and mineral alteration adjacent to a 2 km long segment of the Kern Canyon fault near Lake Isabella, California are studied to characterize the internal structure of the fault zone and to understand the development of fault structure and constitution and the mechanical and chemical processes responsible for them. The 140 km long Kern Canyon fault (KCF) is a fault of 15 km right-lateral separation exhumed from seismogenic depth that cuts batholithic and metamorphic rocks of the southern Sierra Nevada. The fault consists of at least three distinct phases: an early phase of lower-greenschist-grade ductile shear with an S-C' phyllonite, a subsequent, dominant phase of brittle faulting characterized by a through-going zone of cataclastic rock, and a late stage of minor faulting along discontinuous, thin, hematitic gouge zones. The S-C' fabric and subsidiary fault-slip data indicate that both the phyllonitic and cataclastic zones are approximately vertical and strike-slip; slip lineations within the hematitic gouge suggest oblique-slip. The phyllonite zone trends N20-40E and accommodated ~175 m of separation. The cataclastic zone cuts the phyllonite, trends N21E, and consists of foliated and non-foliated cataclasites; it accommodates the majority of displacement along the fault. Abundant veins and fluid-assisted alteration in the rock surrounding the fault zone attest to the presence of fluids of evolving chemistry during both ductile and brittle faulting. Mass balance calculations indicate quartz loss during phyllonite faulting and imply that the fault system was open and experienced a negative change in volume during phyllonite faulting. Mesoscale and microscale fracture intensities decrease with log distance from the foliated cataclasites and approach a relatively low level at approximately 500 m. The internal structure of the Kern Canyon fault is similar to other large displacement faults in that it consists of a broad zone of fractured and altered rock and a narrow zone of intense cataclasis.

Neal, Leslie Ann

2002-01-01T23:59:59.000Z

35

THE EFFECTS OF FAULT-INDUCED STRESS ANISOTROPY ON FRACTURING, FOLDING AND SILL EMPLACEMENT: INSIGHTS FROM THE BOWIE COAL  

E-Print Network (OSTI)

: INSIGHTS FROM THE BOWIE COAL MINES, SOUTHERN PICEANCE BASIN, WESTERN COLORADO by Eric D. Robeck A thesis-INDUCED STRESS ANISOTROPY ON FRACTURING, FOLDING AND SILL EMPLACEMENT: INSIGHTS FROM THE BOWIE COAL MINES. The Bowie underground coal mines of western Colorado expose a reverse-reactivated growth fault

Seamons, Kent E.

36

Integrating complementarity into the 2D displacement discontinuity boundary element method to model faults and fractures with frictional contact properties  

Science Conference Proceedings (OSTI)

We present a two-dimensional displacement discontinuity method (DDM) in combination with a complementarity solver to simulate quasi-static slip on cracks as models for faults and fractures in an otherwise homogeneous, isotropic, linear elastic material. ... Keywords: Boundary element model, Complementarity, Friction, Frictional strength

Elizabeth Ritz; Ovunc Mutlu; David D. Pollard

2012-08-01T23:59:59.000Z

37

Flow dynamics and potential for Biodegradation of Organic Contaminants in Fractured Rock Vadose Zones  

SciTech Connect

We present an experimental approach for investigating the potential for bioremediation of volatile organic chemicals (VOCs) in fractured-rock vadose zones. This approach is based on the coupling of fluid flow dynamics and biotransformation processes. Fluid flow and distribution within fracture networks may be a significant factor in the ability of microorganisms to degrade VOCs, as they affect the availability of substrate, moisture and nutrients. Biological activity can change liquid surface tension and generate biofilms that may change the nettability of solid surfaces, locally alter fracture permeability and redirect infiltrating liquids. Our approach has four components: (1) establishing a conceptual model for fluid and contaminant distribution in the geologic matrix of interest; (2) physical and numerical experiments of liquid seepage in the fracture plane; (3) non-destructive monitoring of biotransformations on rock surfaces at the micron-scale; and, (4) integration of flow and biological activity in natural rock ''geocosms''. Geocosms are core-scale flow cells that incorporate some aspects of natural conditions, such as liquid seepage in the fracture plane and moisture content. The experimental work was performed with rock samples and indigenous microorganisms from the site of the US Department of Energy's Idaho National Engineering and Environmental Laboratory (INEEL), located in a basalt flow basin where VOC contamination threatens the Snake River Aquifer. The insights gained from this approach should contribute to the design of techniques to monitor and stimulate naturally occurring biological activity and control the spread of organic contaminants.

Geller, J.T.; Holman, H.-Y.; Su, T.-S.; Liou, M.S.; Conrad, M.S.; Pruess, K.; Hunter-Devera, J.C.

1998-12-01T23:59:59.000Z

38

Creating infrastructure for seismic microzonation by Geographical Information Systems (GIS): A case study in the North Anatolian Fault Zone (NAFZ)  

Science Conference Proceedings (OSTI)

Although there are many studies for seismic microzonation in the literature, these studies have not covered the whole seismic microzonation processes. Moreover, they have not sufficiently focused on the important subjects, such as significance and use ... Keywords: GIS, North Anatolian Fault Zone, Photogrammetry, Seismic microzonation, Spatiotemporal analysis

T. Turk; U. GüMü?Ay; O. Tatar

2012-06-01T23:59:59.000Z

39

Quasi-explicit time-integration schemes for dynamic fracture with set-valued cohesive zone models  

Science Conference Proceedings (OSTI)

We investigate quasi-explicit time-integration schemes for solving dynamic fracture problems with set-valued cohesive zone models. These schemes combine a central difference time-integration scheme and a partially implicit and lumped treatment of the ... Keywords: Cohesive zone model, Finite elements, Time-integration scheme

D. Doyen; A. Ern; S. Piperno

2013-08-01T23:59:59.000Z

40

Association of coal metamorphism and hydrothermal mineralization in Rough Creek fault zone and Fluorspar District, Western Kentucky  

SciTech Connect

The ambient coal rank (metamorphism) of the Carboniferous coals in the Western Kentucky coalfield ranges from high volatile A bituminous (vitrinite maximum reflectance up to 0.75% R/sub max/) in the Webster syncline (Webster and southern Union Counties) to high volatile C bituminous (0.45 to 0.60% R/sub max/) over most of the remainder of the area. Anomalous patterns of metamorphism, however, have been noted in coals recovered from cores and mines in fault blocks of the Rough Creek fault zone and Fluorspar District. Coals in Gil-30 borehole (Rough Creek faults, Bordley Quadrangle, Union County) vary with no regard for vertical position, from high volatile C(0.55% R/sub max/) to high volatile A (0.89%R/sub max) bituminous. Examination of the upper Sturgis Formation (Missourian/Virgilian) coals revealed that the higher rank (generally above 0.75% R/sub max/) coals had vein mineral assemblages of sphalerite, twinned calcite, and ferroan dolomite. Lower rank coals had only untwinned calcite. Several sites in Webster County contain various coals (Well (No. 8) to Coiltwon (No. 14)) with vitrinite reflectances up to 0.83% R/sub max/ and associated sphalerite mineralization. Mississippian and Lower Pennsylvanian (Caseyville Formation Gentry coal) coals in the mineralized Fluorspar District have ranks to nearly medium volatile bituminous (1.03% R/sub max/). The regional rank trend exhibited by the fualt zones is generally higher rank than the surrounding areas. Sphalerite mineralization in itself is not unique within Illinois basin coals, but if it was partly responsible for the metamorphism of these coals, then the fluid temperature must have been higher within the above mentioned fault complexes.

Hower, J.C.; Fiene, F.L.; Trinkle, E.J.

1983-09-01T23:59:59.000Z

Note: This page contains sample records for the topic "fracture zones faults" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


41

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

Science Conference Proceedings (OSTI)

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.

Barton, C.A.; Zoback, M.D. [Stanford Univ., CA (United States). Dept. of Geophysics; Hickman, S. [Geological Survey, Menlo Park, CA (United States); Morin, R. [Geological Survey, Denver, CO (United States); Benoit, D. [Oxbow Geothermal Corp., Reno, NV (United States)

1998-08-01T23:59:59.000Z

42

Carbon deposition during brittle rock deformation: Changes in electrical properties of fault zones and potential geoelectric phenomena during earthquakes  

Science Conference Proceedings (OSTI)

To investigate potential mechanisms for geoelectric phenomena accompanying earthquakes, we have deformed hollow cylinders of Sioux quartzite to failure in the presence of carbonaceous pore fluids and investigated the resulting changes in electrical conductivity and carbon distribution. Samples were loaded at room temperature or 400 C by a hydrostatic pressure at their outer diameter, increasing pressure at a constant rate to {approx}290 MPa. Pore fluids consisted of pure CO, CO{sub 2}, CH{sub 4} and a 1:1 mixture of CO{sub 2} and CH{sub 4}, each with pore pressures of 2.0 to 4.1 MPa. Failure occurred by the formation of mode II shear fractures transecting the hollow cylinder walls. Radial resistivities of the cylinders fell to 2.9 to 3.1 M{Omega}-m for CO tests and 15.2 to 16.5 M{Omega}-m for CO{sub 2}:CH{sub 4} tests, compared with >23 M{Omega}-m for dry, undeformed cylinders. Carbonaceous fluids had no discernable influence on rock strength. Based on mapping using electron microprobe techniques, carbon occurs preferentially as quasi-continuous films on newly-formed fracture surfaces, but these films are absent from pre-existing surfaces in those same experiments. The observations support the hypothesis that electrical conductivity of rocks is enhanced by the deposition of carbon on fracture surfaces and imply that electrical properties may change in direct response to brittle deformation. They also suggest that the carbon films formed nearly instantaneously as the cracks formed. Carbon film deposition may accompany the development of microfracture arrays prior to and during fault rupture and thus may be capable of explaining precursory and coseismic geoelectric phenomena.

Mathez, E A; Roberts, J J; Duba, A G; Kronenberg, A K; Karner, S L

2008-05-16T23:59:59.000Z

43

Development of a Hydrologic Characterization Technology for Fault Zones Phase II 2nd Report  

E-Print Network (OSTI)

Usually, the drilling fluids and mud are temporarily storedbeen coated with thick drilling fluid, with added polymerdrilling in WF-4 at ~183 m, the zones in WF-1 responded to the lowering and rising of the fluid

Karasaki, Kenzi

2013-01-01T23:59:59.000Z

44

Development of a Hydrologic Characterization Technology for Fault Zones Phase II 2nd Report  

E-Print Network (OSTI)

4-28 4.6.1 Claremont Fm. chert and shalecontact between chert and shale of the Claremont Fm. andzone and strips of black shale. A second zone with mixtures

Karasaki, Kenzi

2013-01-01T23:59:59.000Z

45

Microstructures and Rheology of a Limestone-Shale Thrust Fault  

E-Print Network (OSTI)

The Copper Creek thrust fault in the southern Appalachians places Cambrian over Ordovician sedimentary strata. The fault accommodated displacement of 15-20 km at 100-180 °C. Along the hanging wall-footwall contact, microstructures within a ~2 cm thick calcite and shale shear zone suggest that calcite, not shale, controlled the rheology of the shear zone rocks. While shale deformed brittley, plasticity-induced fracturing in calcite resulted in ultrafine-grained (shale into the shear zone, shows the evolution of rheology within the shear zone. Sedimentary laminations 1 cm below the shear zone are cut by minor faults, stylolites, and fault-parallel and perpendicular calcite veins. At vein intersections, calcite grain size is reduced (to ~0.3 ?m), and microstructures include inter-and-intragranular fractures, four-grain junctions, and interpenetrating boundaries. Porosity rises to 6 percent from shale clasts (5-350 ?m) lie within an ultrafine-grained calcite (shale matrix. Ultrafinegrained calcite (shale. Calcite vein microstructures suggest veins continued to form during deformation. Fractures at twin-twin and twin-grain boundary intersections suggest grain size reduction by plasticity-induced fracturing, resulting in <1 ?m grains. Interpenetrating boundaries, four-grain junctions, and no LPO indicate the ultrafine-grained calcite deformed by viscous grain boundary sliding. The evolution of the ultrafine-grain shear zone rocks by a combination of plastic and brittle processes and the deformation of the interconnected network of ultrafine-grained calcite by viscous GBS enabled a large displacement along a narrow fault zone.

Wells, Rachel Kristen

2010-12-01T23:59:59.000Z

46

Earthquake source parameters and fault kinematics in the Eastern California Shear Zone  

E-Print Network (OSTI)

Based on waveform data from a profile of aftershocks following the north-south trace of the June 28, 1992 Landers rupture across the Mojave desert, we construct a new velocity model for the Mojave region which features a thin, slow crust. Using this model, we obtain source parameters, including depth and duration, for each of the aftershocks in the profile, and in addition, any significant (M>3.7) Joshua Tree--Landers aftershock between April, 1992 and October, 1994 for which coherent TERRAscope data were available. In all, we determine source parameters and stress-drops for 45 significant (M_w > 4) earthquakes associated with the Joshua Tree and Landers sequences, using a waveform grid-search algorithm. Stress drops for these earthquakes appear to vary systematically with location, with respect to previous seismic activity, proximity to previous rupture (i.e., with respect to the Landers rupture), and with tectonic province. In general, for areas north of the Pinto Mountain fault, stress-drops of aftershocks...

Jones, L E; Jones, Laura E.; Helmberger, Donald V.

1998-01-01T23:59:59.000Z

47

Natural gas exploration associated with fracture systems in Alleghenian thrust faults in the Greenbrier Formation, southern West Virginia.  

E-Print Network (OSTI)

??A hydrocarbon play of southern West Virginia targets the intersection of thrust faults with specific Mississippian reservoirs. Typical study area wells yield initial production rates… (more)

Edmonds, Craig A.

2004-01-01T23:59:59.000Z

48

Application of Control Charts for Detecting Faults in Variable ...  

Science Conference Proceedings (OSTI)

... where Tzone = zone temperature, CSP = cooling setpoint ... Fault Implementation and Impact To test ... fault imple- mentations and impacts are provided ...

49

Reservoir-Scale Fracture Permeability in the Dixie Valley, Nevada,  

Open Energy Info (EERE)

Reservoir-Scale Fracture Permeability in the Dixie Valley, Nevada, Reservoir-Scale Fracture Permeability in the Dixie Valley, Nevada, Geothermal Field Jump to: navigation, search OpenEI Reference LibraryAdd to library Conference Paper: Reservoir-Scale Fracture Permeability in the Dixie Valley, Nevada, Geothermal Field Abstract Borehole televiewer, temperature, and flowmeter datarecorded in six wells penetrating a geothermalreservoir associated with the Stillwater fault zone inDixie Valley, Nevada, were used to investigate therelationship between reservoir permeability and thecontemporary in situ stress field. Data from wellsdrilled into productive and nonproductive segments ofthe Stillwater fault zone indicate that permeability inall wells is dominated by a relatively small number offractures striking parallel to the local trend of

50

Accommodation Zone | Open Energy Information  

Open Energy Info (EERE)

source source History View New Pages Recent Changes All Special Pages Semantic Search/Querying Get Involved Help Apps Datasets Community Login | Sign Up Search Page Edit History Facebook icon Twitter icon » Accommodation Zone Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Print PDF Accommodation Zone Dictionary.png Accommodation Zone: Accommodation zones occur at fault intersections consisting of belts of interlocking, oppositely dipping normal faults. Multiple subsurface fault intersections in these zones are a favorable host for geothermal activity. Other definitions:Wikipedia Reegle Controlling Structures List of controlling structures typically associated with geothermal systems: Major Normal Fault Termination of a Major Normal Fault Stepover or Relay Ramp in Normal Fault Zones

51

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

DOE Green Energy (OSTI)

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.

M. D. Zoback

1999-03-08T23:59:59.000Z

52

Fracture Permeability and In Situ Stress in the Dixie Valley, Nevada,  

Open Energy Info (EERE)

Fracture Permeability and In Situ Stress in the Dixie Valley, Nevada, Fracture Permeability and In Situ Stress in the Dixie Valley, Nevada, Geothermal Reservoir Jump to: navigation, search OpenEI Reference LibraryAdd to library Journal Article: Fracture Permeability and In Situ Stress in the Dixie Valley, Nevada, Geothermal Reservoir Abstract Borehole televiewer, temperature and flowmeter logs and hydraulic fracturing stress measurements conducted in six wells penetrating a geothermal reservoir associated with the Stillwater fault zone in Dixie Valley, Nevada, were used to investigate the relationship between reservoir permeability and the contemporary in situ stress field. Data from wells drilled into productive and nonproductive segments of the Stillwater fault zone indicate that permeability in all wells is dominated by a relatively

53

Major Normal Fault | Open Energy Information  

Open Energy Info (EERE)

Major Normal Fault Major Normal Fault Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Print PDF Major Normal Fault Dictionary.png Major Normal Fault: Normal faults are structures in which the hanging wall is down dropped along the fault plane relative to the foot wall. They are the predominant type of structure in extensional tectonic environments, but are commonly encountered in a number of geologic settings. Other definitions:Wikipedia Reegle Controlling Structures List of controlling structures typically associated with geothermal systems: Major Normal Fault Termination of a Major Normal Fault Stepover or Relay Ramp in Normal Fault Zones Apex or Salient of Normal Fault Fault Intersection Accommodation Zone Displacement Transfer Zone Pull-Apart in Strike-Slip Fault Zone

54

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

DOE Green Energy (OSTI)

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.

Hickman, S. [Geological Survey, Menlo Park, CA (United States); Zoback, M. [Stanford Univ., CA (United States). Dept. of Geophysics

1998-08-01T23:59:59.000Z

55

Structural Settings Of Hydrothermal Outflow- Fracture Permeability  

Open Energy Info (EERE)

Settings Of Hydrothermal Outflow- Fracture Permeability Settings Of Hydrothermal Outflow- Fracture Permeability Maintained By Fault Propagation And Interaction Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Journal Article: Structural Settings Of Hydrothermal Outflow- Fracture Permeability Maintained By Fault Propagation And Interaction Details Activities (1) Areas (1) Regions (0) Abstract: Hydrothermal outflow occurs most commonly at the terminations of individual faults and where multiple faults interact. These areas of fault propagation and interaction are sites of elevated stress termed breakdown regions. Here, stress concentrations cause active fracturing and continual re-opening of fluid-flow conduits, permitting long-lived hydrothermal flow despite potential clogging of fractures due to mineral precipitation. As

56

Neogene carbonate exploration play concepts for Northern New Guinea: New iteration from field work and seismic stratigraphy along the Northern New Guinea Fault Zone  

Science Conference Proceedings (OSTI)

Recent field reconnaissance, petrography, nanno and foraminifera age determinations, and seismic stratigraphy of the Sepik and Piore subbasins of northern New Guinea reveal the existence of an extensive, tectonically unstable, Miocene-Pliocene carbonate shelf system. These findings represent the first recorded evidence of northern Papuan limestones coeval in age to those of the hydrocarbon productive Salawati Basin of Irian Jaya. Moreover, these observations also demonstrate the significance of episodic activities of the northern New Guinea fault zone upon the changes in carbonate sedimentation and diagenesis. During the Neogene, algal biosparites to foraminiferal biomicrites defined the clean portion of a mixed clastic-carbonate shelf system of the northern New Guinea basin, which began at the central New Guinea cordillera and deepened northward. This shelf was interrupted by coral-coralline algal boundstone fringing- to patch-reef buildups with associated skeletal grainstones. Clean carbonates were spatially and temporally restricted to basement blocks, which episodically underwent uplift while terrigenous dilutes carbonates were more common in adjacently subsiding basement block bathymetric lows. These tectonic expressions were caused by the spatially transient nature of constraining bends of the evolving north New Guinea faults. As shown by seismic stratigraphy, by the late Miocene to the early Pliocene the uplift of the Bewani-Torricelli Mountains sagittally divided the shelf of the northern New Guinea basin into the Ramu-Sepik and the Piore basins. Continued regional sinistral transpression between the Pacific and the New Guinea leading edge of the Indo-Australian plates led to the reverse tilting of the Piore basin, the shallowing of the former distal shelf with concomitant extensive biolithite development (e.g., on subsiding volcanic islands) eventual uplifting of the Oenake Range, and en echelon faulting of the Bewani-Torricelli Mountains.

Pigott, J.D.; Geiger, C. (Univ. of Oklahoma, Norman, OK (United States))

1994-07-01T23:59:59.000Z

57

Single fracture aperture patterns: Characterization by slit-island fractal analysis  

Science Conference Proceedings (OSTI)

Single fracture measurements are difficult to obtain, but they are the only means we have to observe and study natural fracture morphology. The character of the fracture openings (apertures) is often one of the primary factors controlling fluid flow in the fracture. In particular, the shape, distribution, and connectivity of contact areas and flow channels can affect the relative permeability of wetting and non-wetting fluid phases in unsaturated systems. In this paper we use three methods of fractal analysis (the slit-island, the divider, and the variogram) as well as statistical and geostatistical analysis to characterize the geometry of measured fracture apertures obtained from two different fractured rock specimens from the field. One of these is a granitic fracture (crack) of homogeneous lithology and no displacement, the other is a fracture (fault) obtained from a highly altered fault zone, containing striations and slickensides. We discuss the fractal and geostatistical analysis of these two fractures in the context of what information is most helpful for making predictions about fluid flow in single fractures.

Cox, B.L.; Wang, J.S.Y.

1993-01-01T23:59:59.000Z

58

New observations of infiltration through fractured alluvium in Yucca Flat, Nevada Test Site: A preliminary field investigation  

Science Conference Proceedings (OSTI)

Regional tectonics coupled with the subsurface detonation of nuclear explosives has caused widespread fracturing of the alluvium of Yucca Flat. Fractures deeper than 30 meters have been observed in boreholes. Some of these fractures are large enough to capture significant amounts of runoff during storm events. Evidence of stream capture by fractures and observations of runoff flowing into open fractures give qualitative evidence of infiltration to depths greater than several meters and possibly to the saturated zone. Our field observations contradict the assumption that little infiltration occurs on Yucca Flat. The larger, hydrologically important fractures are associated with geologic faults or the regional stress field. Additional field studies are needed to investigate the impact of fractures on the transport of contaminants.

Kao, C.S. [California Univ., Berkeley, CA (United States). Dept. of Civil Engineering; Smith, D.K. [Lawrence Livermore National Lab., CA (United States); McKinnis, W.B. [Lawrence Livermore National Lab., Mercury, NV (United States)

1994-02-01T23:59:59.000Z

59

Hydrothermal brecciation in the Jemez Fault zone, Valles Caldera, New Mexico: Results from CSDP (Continental Scientific Drilling Program) corehole VC-1  

DOE Green Energy (OSTI)

Paleozoic and Precambrian rocks intersected deep in Continental Scientific Drilling Program corehole VC-1, adjacent to the late Cenozoic Valles caldera complex, have been disrupted to form a spectacular breccia sequence. The breccias are of both tectonic and hydrothermal origin, and probably formed in the Jemez fault zone, a major regional structure with only normal displacement since mid-Miocene. Tectonic breccias are contorted, crushed, sheared, and granulated; slickensides are commmon. Hydrothermal breccias, by contrast, lack these frictional textures, but arej commonly characterized by fluidized matrix foliation and prominent clast rounding. Fluid inclusions in the hydrothermal breccias are dominantly two-phase, liquid-rich at room temperature, principally secondary, and form two distinctly different compositional groups. Older inclusions, unrelated to brecciation, are highly saline and homogenize to the liquid phase in the temperature range 189 to 246/sup 0/C. Younger inclusions, in part of interbreccia origin, are low-salinity and homogenize (also to liquid) in the range 230 to 283/sup 0/C. Vapor-rich inclusions locally trapped along with these dilute liquid-rich inclusions document periodic boiling. These fluid-inclusion data, together with alteration assemblages and textures as well as the local geologic history, have been combined to model hydrothermal brecciation at the VC-1 site.

Hulen, J.B.; Nielson, D.L.

1987-06-01T23:59:59.000Z

60

Modeling Hydrogeological and Geomenchanical Processes Related to CO2 Injection in a Faulted Multilayer System  

E-Print Network (OSTI)

consists of highly fractured shale across the first caprockInitially, the fractured shale zones are considered sealedlayers with caprocks of shale as well as highly fractured

Rutqvist, Jonny; Birkholzer, Jens; Tsang, Chin-Fu

2006-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "fracture zones faults" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


61

Fracture Detection and Water Sweep Characterization Using Single-well Imaging, Vertical Seismic Profiling and Cross-dipole Methods in Tight and Super-k Zones, Haradh II, Saudi Arabia  

E-Print Network (OSTI)

This work was conducted to help understand a premature and irregular water breakthrough which resulted from a waterflooding project in the increment II region of Haradh oilfield in Saudi Arabia using different geophysical methods. Oil wells cannot sustain the targeted oil production rates and they die much sooner than expected when water enters the wells. The study attempted to identify fracture systems and their role in the irregular water sweep. Single-well acoustic migration imaging (SWI), walkaround vertical seismic profiling (VSP) and cross-dipole shear wave measurements were used to detect anisotropy caused by fractures near and far from the borehole. The results from all the different methods were analyzed to understand the possible causes of water fingering in the field and determine the reasons for discrepancies and similarities of results of the different methods. The study was done in wells located in the area of the irregular water encroachment in Haradh II oilfield. Waterflooding was performed, where water was injected in the water injector wells drilled at the flanks of Harahd II toward the oil producer wells. Unexpected water coning was noticed in the west flank of the field. While cross-dipole and SWI measurements of a small-scale clearly identify a fracture oriented N60E in the upper tight zone of the reservoir, the VSP measurements of a large-scale showed a dominating fracture system to the NS direction in the upper highpermeability zone of the same reservoir. These results are consistent with the directions of the three main fracture sets in the field at N130E, N80E and N20E, and the direction of the maximum horizontal stress in the field varies between N50E and N90E. Results suggested that the fracture which is detected by cross-dipole at 2 to 4 ft from the borehole is the same fracture detected by SWI 65 ft away from the borehole. This fracture was described using the SWI as being 110 ft from top to bottom, having an orientation of N60E and having an angle of dip of 12° relative to the vertical borehole axis. The detected fracture is located in the tight zone of the reservoir makes a path for water to enter the well from that zone. On the Other hand, the fractures detected by the large-scale VSP measurements in the NS direction are responsible for the high-permeability in the upper zone of the reservoir.

Aljeshi, Hussain Abdulhadi A.

2012-05-01T23:59:59.000Z

62

Quaternary faulting of Deschutes County, Oregon.  

E-Print Network (OSTI)

??Sixty-one normal faults were identified in a 53-kilometer long by 21-kilometer wide northwest-trending zone in central and northern Deschutes County, Oregon. The faults are within… (more)

Wellik, John M.

2008-01-01T23:59:59.000Z

63

Displacement Transfer Zone | Open Energy Information  

Open Energy Info (EERE)

Displacement Transfer Zone Displacement Transfer Zone Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Print PDF Displacement Transfer Zone Dictionary.png Displacement Transfer Zone: Displacement transfer zones facilitate the transfer of strain between normal and strike-slip faults. Intersections between strike-slip faults in the Walker Lane and N- to NNE-striking normal faults commonly host geothermal systems, focused along the normal faults proximal to their dilational intersections with nearby strike-slip faults. Other definitions:Wikipedia Reegle Controlling Structures List of controlling structures typically associated with geothermal systems: Major Normal Fault Termination of a Major Normal Fault Stepover or Relay Ramp in Normal Fault Zones Apex or Salient of Normal Fault

64

Gravity and fault structures, Long Valley caldera, California  

DOE Green Energy (OSTI)

The main and catastrophic phase of eruption in Long Valley occurred 0.73 m.y. ago with the eruption of over 600 km/sup 3/ of rhyolitic magma. Subsequent collapse of the roof rocks produced a caldera which is now elliptical in shape, 32 km east-west by 17 km north-south. The caldera, like other large Quarternary silicic ash-flow volcanoes that have been studied by various workers, has a nearly coincident Bouguer gravity low. Earlier interpretations of the gravity anomaly have attributed the entire anomaly to lower density rocks filling the collapsed structure. However, on the basis of many additional gravity stations and supporting subsurface data from several new holes, a much more complex and accurate picture has emerged of caldera structure. From a three-dimensional inversion of the residual Bouguer gravity data we can resolve discontinuities that seem to correlate with extensions of pre-caldera faults into the caldera and faults associated with the ring fracture. Some of these faults are believed related to the present-day hydrothermal upflow zone and the zone of youngest volcanic activity within the caldera.

Carle, S.F.; Goldstein, N.E.

1987-07-01T23:59:59.000Z

65

Fault finder  

DOE Patents (OSTI)

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.

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

1986-01-01T23:59:59.000Z

66

An integrated methodology for characterizing flow and transport processes in fractured rock  

E-Print Network (OSTI)

Unsaturated Zone, Yucca Mountain, Nevada. Water-Resourcesof the unsaturated zone of Yucca Mountain, NV from three-in fractured tuffs of Yucca Mountain, Vadose Zone Journal,

Wu, Yu-Shu

2007-01-01T23:59:59.000Z

67

A mountain-scale model for characterizing unsaturated flow and transport in fractured tuffs of Yucca Mountain  

E-Print Network (OSTI)

to Fault Zones at Yucca Mountain, Nevada, International2003c. Calibration of Yucca Mountain Unsaturated Zone FlowUnsaturated Zone, Yucca Mountain, Nevada, Water-Resources

Wu, Yu-Shu; Lu, Guoping; Zhang, Keni; Bodvarsson, G.S.

2003-01-01T23:59:59.000Z

68

CHARACTERIZATION OF IN-SITU STRESS AND PERMEABILITY IN FRACTURED RESERVOIRS  

Science Conference Proceedings (OSTI)

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.

Daniel R. Burns; M. Nafi Toksoz

2005-08-01T23:59:59.000Z

69

Evaluation of the relationship between fracture conductivity, fracture fluid production, and effective fracture length  

E-Print Network (OSTI)

Low-permeability gas wells often produce less than predicted after a fracture treatment. One of the reasons for this is that fracture lengths calculated after stimulation are often less than designed lengths. While actual fracture lengths may be shorter due to fracture growth out of zone, improper proppant settling, or proppant flowback, short calculated fracture lengths can also result from incorrect analysis techniques. It is known that fracturing fluid that remains in the fracture and formation after a hydraulic fracture treatment can decrease the productivity of a gas well by reducing the relative permeability to gas in the region invaded by this fluid. However, the relationships between fracture fluid cleanup, effective fracture length, and well productivity are not fully understood. In this work I used reservoir simulation to determine the relationship between fracture conductivity, fracture fluid production, effective fracture length, and well productivity. I simulated water saturation and pressure profiles around a propped fracture, tracked gas production along the length of the propped fracture, and quantified the effective fracture length (i.e., the fracture length under single-phase flow conditions that gives similar performance as for multiphase flow conditions), the "cleanup" fracture length (i.e., the fracture length corresponding to 90% cumulative gas flow rate into the fracture), and the "apparent" fracture length (i.e., the fracture length where the ratio of multiphase to single-phase gas entry rate profiles is unity). This study shows that the proppant pack is generally cleaned up and the cleanup lengths are close to designed lengths in relatively short times. Although gas is entering along entire fracture, fracturing fluid remains in the formation near the fracture. The water saturation distribution affects the gas entry rate profile, which determines the effective fracture length. Subtle changes in the gas rate entry profile can result in significant changes in effective fracture length. The results I derived from this work are consistent with prior work, namely that greater fracture conductivity results in more effective well cleanup and longer effective fracture lengths versus time. This study provides better explanation of mechanisms that affect fracturing fluid cleanup, effective fracture length, and well productivity than previous work.

Lolon, Elyezer P.

2004-12-01T23:59:59.000Z

70

Discrete Fracture Network Models for Risk Assessment of Carbon Sequestration in Coal  

Science Conference Proceedings (OSTI)

A software package called DFNModeler has been developed to assess the potential risks associated with carbon sequestration in coal. Natural fractures provide the principal conduits for fluid flow in coal-bearing strata, and these fractures present the most tangible risks for the leakage of injected carbon dioxide. The objectives of this study were to develop discrete fracture network (DFN) modeling tools for risk assessment and to use these tools to assess risks in the Black Warrior Basin of Alabama, where coal-bearing strata have high potential for carbon sequestration and enhanced coalbed methane recovery. DFNModeler provides a user-friendly interface for the construction, visualization, and analysis of DFN models. DFNModeler employs an OpenGL graphics engine that enables real-time manipulation of DFN models. Analytical capabilities in DFNModeler include display of structural and hydrologic parameters, compartmentalization analysis, and fluid pathways analysis. DFN models can be exported to third-party software packages for flow modeling. DFN models were constructed to simulate fracturing in coal-bearing strata of the upper Pottsville Formation in the Black Warrior Basin. Outcrops and wireline cores were used to characterize fracture systems, which include joint systems, cleat systems, and fault-related shear fractures. DFN models were constructed to simulate jointing, cleating, faulting, and hydraulic fracturing. Analysis of DFN models indicates that strata-bound jointing compartmentalizes the Pottsville hydrologic system and helps protect shallow aquifers from injection operations at reservoir depth. Analysis of fault zones, however, suggests that faulting can facilitate cross-formational flow. For this reason, faults should be avoided when siting injection wells. DFN-based flow models constructed in TOUGH2 indicate that fracture aperture and connectivity are critical variables affecting the leakage of injected CO{sub 2} from coal. Highly transmissive joints near an injection well have potential to divert a large percentage of an injected CO{sub 2} stream away from a target coal seam. However, the strata-bound nature of Pottsville fracture systems is a natural factor that mitigates the risk of long-range leakage and surface seepage. Flow models indicate that cross-formational flow in strata-bound joint networks is low and is dissipated by about an order of magnitude at each successive bedding contact. These models help confirm that strata-bound joint networks are self-compartmentalizing and that the thick successions of interbedded shale and sandstone separating the Pottsville coal zones are confining units that protect shallow aquifers from injection operations at reservoir depth. DFN models are powerful tools for the simulation and analysis of fracture networks and can play an important role in the assessment of risks associated with carbon sequestration and enhanced coalbed methane recovery. Importantly, the stochastic nature DFN models dictates that they cannot be used to precisely reproduce reservoir conditions in a specific field area. Rather, these models are most useful for simulating the fundamental geometric and statistical properties of fracture networks. Because the specifics of fracture architecture in a given area can be uncertain, multiple realizations of DFN models and DFN-based flow models can help define variability that may be encountered during field operations. Using this type of approach, modelers can inform the risk assessment process by characterizing the types and variability of fracture architecture that may exist in geologic carbon sinks containing natural fractures.

Jack Pashin; Guohai Jin; Chunmiao Zheng; Song Chen; Marcella McIntyre

2008-07-01T23:59:59.000Z

71

Proceedings of the Second International Symposium on Dynamics of Fluids in Fractured Rock  

E-Print Network (OSTI)

toward the heat source, or into the rock underlying the heatcharacterizing DNAPL source zones in fractured rock at theby a point source injection in fractured rock with multiple

Faybishenko, Boris; Witherspoon, Paul A.

2004-01-01T23:59:59.000Z

72

Geomechanical Simulation of Fluid-Driven Fractures  

SciTech Connect

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.

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

2012-11-30T23:59:59.000Z

73

HYDRAULIC FRACTURING  

NLE Websites -- All DOE Office Websites (Extended Search)

HYDRAULIC FRACTURING In addition to the recovery processes featured in this series of drawings, hydraulic fracturing is included as an example of technologies that contribute to...

74

Potential Contaminant Pathways from Hydraulically Fractured Shale to Aquifers. Ground Water. doi: 10.1111/j.1745-6584.2012.00933.x New Hampshire Department of Environmental Services (NHDES). 2010. “Well Development by Hydrofracturing.” http://des.nh.gov/o  

E-Print Network (OSTI)

Hydraulic fracturing of deep shale beds to develop natural gas has caused concern regarding the potential for various forms of water pollution. Two potential pathways—advective transport through bulk media and preferential flow through fractures—could allow the transport of contaminants from the fractured shale to aquifers. There is substantial geologic evidence that natural vertical flow drives contaminants, mostly brine, to near the surface from deep evaporite sources. Interpretative modeling shows that advective transport could require up to tens of thousands of years to move contaminants to the surface, but also that fracking the shale could reduce that transport time to tens or hundreds of years. Conductive faults or fracture zones, as found throughout the Marcellus shale region, could reduce the travel time further. Injection of up to 15,000,000 L of fluid into the shale generates high pressure at the well, which decreases with distance from the well and with time after injection as the fluid advects through the shale. The advection displaces native fluids, mostly brine, and fractures the bulk media widening existing fractures. Simulated pressure returns to pre-injection levels in about 300 d. The overall system requires from 3 to 6 years to reach a new equilibrium reflecting the significant changes caused by fracking the shale, which could allow advective transport to aquifers in less than 10 years. The rapid expansion of hydraulic fracturing requires that monitoring systems be employed to track the movement of contaminants and that gas wells have a reasonable offset from faults.

Tom Myers

2012-01-01T23:59:59.000Z

75

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

Science Conference Proceedings (OSTI)

The National Center for Nuclear Security (NCNS), established by the U.S. Department of Energy, National Nuclear Security Administration, is conducting a series of explosive tests at the Nevada National Security Site (NNSS; formerly the Nevada Test 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 (CTBT). The initial NCNS project is a series of explosive tests, known collectively as the Source Physics Experiment at the NNSS (SPE-N), being conducted in granitic rocks at the Climax stock in northern Yucca Flat. The SPE-N test series is designed to study the generation and propagation of seismic waves. The data will be used to improve the predictive capability of calculational models for detecting and characterizing underground explosions. The first SPE-N test (SPE-N-1) was a “calibration” shot conducted in May 2011, using 100 kilograms (kg) of explosives at the depth of 54.9 meters (m) (180 feet [ft]) 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 (150 ft) in the same source hole. Following the SPE-N-2 test, 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 desire was to determine the position of the damage zone near the shot point, at least on the northeast side, where the core hole penetrated it. The three-dimensional shape and symmetry of the damage zone are unknown at this time. Rather than spherical in shape, the dimensions of the damage zone could be influenced by the natural fracture sets in the vicinity. Geologic characterization of the borehole 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 laboratory tests (to be reported by SNL). A significant natural fault zone was encountered in the U-15n#10 angle core hole between the drilled depths of 149 and 155 ft (straight-line distance or range station [RS] from the shot point of 7.5 to 5.7 m). However, several of the fractures observed in the U-15n#10 hole are interpreted as having been caused by the explosion. These 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. The most distant fracture from the shot point that could be interpreted as having been caused by the explosion was seen at approximately RS 10.0 m. No other possibly explosion-induced fractures are apparent above the fault, but are common starting at RS 5.4 m, which is below the fault. It is unknown how the fault zone might have affected the propagation of seismic waves or how the materials in the fault zone (altered granite, breccia, gouge) were affected by the explosion. From RS 3.3 m to the end of the recovered core at RS 1.6 m, 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.

,

2012-09-18T23:59:59.000Z

76

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

SciTech Connect

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.

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

2009-03-30T23:59:59.000Z

77

Seismic studies of a massive hydraulic fracturing experiment  

DOE Green Energy (OSTI)

During a massive hydraulic fracturing experiment carried out at Fenton Hill, New Mexico, 850 microearthquakes, ranging in magnitudes from -3 to 0, were located reliably using arrival times recorded at a set of 5 downhole geophone stations. A subset of these events were located using an upgraded hodogram technique. The seismicity defines a tabular zone with horizontal extent of 900 m, vertical extent of 800 m, and thickness of 150 m. This zone strikes N340/sup 0/E, and dips 75/sup 0/ to the east; its position indicates that no hydraulic connection between the two predrilled wells could be achieved by the fracturing. The distribution of locations obtained from arrival times shows good agreement with those derived from hodograms. Well constrained fault plane solutions were determined for 26 of the larger microearthquakes observed at a surface seismic net. Most solutions display one nearly vertical nodal plane that strikes close to N - S, and a T axis that trends roughly E - W, in agreement with regional indicators of the least principal stress direction. 9 refs., 6 figs.

House, L.; Keppler, H.; Kaieda, H.

1985-01-01T23:59:59.000Z

78

Anomalous zones in Gulf Coast Salt domes with special reference to Big Hill, TX, and Weeks Island, LA  

Science Conference Proceedings (OSTI)

Anomalous features in Gulf Coast Salt domes exhibit deviations from normally pure salt and vary widely in form from one dome to the next, ranging considerably in length and width. They have affected both conventional and solution mining in several ways. Gas outbursts, insolubles, and potash (especially carnallite) have led to the breakage of tubing in a number of caverns, and caused irregular shapes of many caverns through preferential leaching. Such anomalous features essentially have limited the lateral extent of conventional mining at several salt mines, and led to accidents and even the closing of several other mines. Such anomalous features, are often aligned in anomalous zones, and appear to be related to diapiric processes of salt dome development. Evidence indicates that anomalous zones are found between salt spines, where the differential salt intrusion accumulates other materials: Anhydrite bands which are relatively strong, and other, weaker impurities. Shear zones and fault displacement detected at Big Hill and Weeks Island domes have not yet had any known adverse impacts on SPR oil storage, but new caverns at these sites conceivably may encounter some potentially adverse conditions. Seismic reflection profiles at Big Hill dome have shown numerous fractures and faults in the caprock, and verified the earlier recognition of a major shear zone transecting the entire salt stock and forming a graben in the overlying caprock. Casing that is placed in such zones can be at risk. Knowledge of these zones should create awareness of possible effects rather than preclude the future emplacement of caverns. To the extent possible, major anomalous zones and salt stock boundaries should be avoided. Shear zones along overhangs may be particularly hazardous, and otherwise unknown valleys in the top of salt may occur along shear zones. These zones often can be mapped geophysically, especially with high-resolution seismic techniques.

Neal, J.T. [Sandia National Labs., Albuquerque, NM (United States); Magorian, T.R. [Magorian (Thomas R.), Amherst, NY (United States); Thoms, R.L. [AGM, Inc., College Station, TX (United States); Autin, W.J.; McCulloh, R.P. [Louisiana Geological Survey, Baton Rouge, LA (United States); Denzler, S.; Byrne, K.O. [Acres International Corp., Amherst, NY (United States)

1993-07-01T23:59:59.000Z

79

Definition: Displacement Transfer Zone | Open Energy Information  

Open Energy Info (EERE)

Definition Definition Edit with form History Facebook icon Twitter icon » Definition: Displacement Transfer Zone Jump to: navigation, search Dictionary.png Displacement Transfer Zone Displacement transfer zones facilitate the transfer of strain between normal and strike-slip faults. Intersections between strike-slip faults in the Walker Lane and N- to NNE-striking normal faults commonly host geothermal systems, focused along the normal faults proximal to their dilational intersections with nearby strike-slip faults.[2] View on Wikipedia Wikipedia Definition References ↑ James E. Faulds,Nicholas H. Hinz,Mark F. Coolbaugh,Patricia H. Cashman,Christopher Kratt,Gregory Dering,Joel Edwards,Brett Mayhew,Holly McLachlan. 2011. Assessment of Favorable Structural Settings of Geothermal

80

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

Open Energy Info (EERE)

Fault Mapping At Raft River Geothermal Area (1993) Fault Mapping At Raft River Geothermal Area (1993) Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Exploration Activity: Fault Mapping At Raft River Geothermal Area (1993) Exploration Activity Details Location Raft River Geothermal Area Exploration Technique Fault Mapping Activity Date 1993 Usefulness useful DOE-funding Unknown Exploration Basis Geologic mapping, strain and kinematic analysis Notes The mountains expose a detachment fault that separates a hanging wall of Paleozoic rocks from Proterozoic and Archean rocks of the footwall. Beneath the detachment lies a 100 to 300m-thick top-to-the-east extensional shear zone. Geologic mapping, strain and kinematic analysis, and 40Ar/39Ar thermochronology suggest that the shear zone and detachment fault had an

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81

Dolomitization and dedolomitization models in a fractured reservoir, Reed City oil field, Michigan  

Science Conference Proceedings (OSTI)

Hydrocarbon production in the Michigan basin is essentially from pinnacle reefs or fractured reservoirs. The epigenetically formed porous dolomite reservoir rock is intimately related to the shear faults (channelways for rising high Mg/Ca ratio fluids) and to the resulting shear folds, the latter showing dolomite/calcite ratios increasing generally from outer closure to the fold axes. The Reed City field (anticline) of western Michigan represents a dramatic exception to this picture with the dolomite/calcite ratio increasing from outer closure to maximum part way up the limbs then decreasing to the axis. This lowest zone is the only unit not dedolomitized, a fact perhaps commensurate with its low stratigraphic position at the bottom of (and apparently beyond the reach of) the descending high-calcium, low-magnesium waters what brought about the dedolomitization. The dedolomitization model would call for a shallow water to exposed oxidizing environment, possible with the position of this area astride the West Michigan Barrier that separates a lagoonal facies from a more open sea facies to the east. Thus, waters with a high Ca/Mg ratio passed down the same shear faults that earlier were channelways for the rising high Mg/Ca ratio waters. On the bases of isopach, structure and dolomite/calcite (Isodol) maps, one can piece together a reasonably chronological sequence of pre-Dundee shear faulting and folding, post-Traverse upward migration of dolomitizing fluids, upward migration of hydrocarbons along the shear faults, downward-moving dedolomitizing fluids, and a later episode of faulting (especially shear cross-faults).

Carlton, R.R.; Prouty, C.E.

1983-03-01T23:59:59.000Z

82

Numerical Investigation of Interaction Between Hydraulic Fractures and Natural Fractures  

E-Print Network (OSTI)

Hydraulic fracturing of a naturally-fractured reservoir is a challenge for industry, as fractures can have complex growth patterns when propagating in systems of natural fractures in the reservoir. Fracture propagation near a natural fracture (NF) considering interaction between a hydraulic fracture (HF) and a pre-existing NF, has been investigated comprehensively using a two dimensional Displacement Discontinuity Method (DDM) Model in this thesis. The rock is first considered as an elastic impermeable medium (with no leakoff), and then the effects of pore pressure change as a result of leakoff of fracturing fluid are considered. A uniform pressure fluid model and a Newtonian fluid flow model are used to calculate the fluid flow, fluid pressure and width distribution along the fracture. Joint elements are implemented to describe different NF contact modes (stick, slip, and open mode). The structural criterion is used for predicting the direction and mode of fracture propagation. The numerical model was used to first examine the mechanical response of the NF to predict potential reactivation of the NF and the resultant probable location for fracture re-initiation. Results demonstrate that: 1) Before the HF reaches a NF, the possibility of fracture re-initiation across the NF and with an offset is enhanced when the NF has weaker interfaces; 2) During the stage of fluid infiltration along the NF, a maximum tensile stress peak can be generated at the end of the opening zone along the NF ahead of the fluid front; 3) Poroelastic effects, arising from fluid diffusion into the rock deformation can induce closure and compressive stress at the center of the NF ahead of the HF tip before HF arrival. Upon coalescence when fluid flows along the NF, the poroelastic effects tend to reduce the value of the HF aperture and this decreases the tension peak and the possibility of fracture re-initiation with time. Next, HF trajectories near a NF were examined prior to coalesce with the NF using different joint, rock and fluid properties. Our analysis shows that: 1) Hydraulic fracture trajectories near a NF may bend and deviate from the direction of the maximum horizontal stress when using a joint model that includes initial joint deformation; 2) Hydraulic fractures propagating with higher injection rate or fracturing fluid of higher viscosity propagate longer distance when turning to the direction of maximum horizontal stress; 3) Fracture trajectories are less dependent on injection rate or fluid viscosity when using a joint model that includes initial joint deformation; whereas, they are more dominated by injection rate and fluid viscosity when using a joint model that excludes initial joint deformation.

Xue, Wenxu

2010-12-01T23:59:59.000Z

83

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

Open Energy Info (EERE)

River detachment fault and shear zone by study of spatial gradients in 40Ar39 A and fission track cooling ages of footwall rocks and cooling histories and by comparison of...

84

Upper crustal faulting in an obliquely extending orogen, structural control  

Open Energy Info (EERE)

faulting in an obliquely extending orogen, structural control faulting in an obliquely extending orogen, structural control on permeability and production in the Coso Geothermal Field, eastern California Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Conference Proceedings: Upper crustal faulting in an obliquely extending orogen, structural control on permeability and production in the Coso Geothermal Field, eastern California Details Activities (1) Areas (1) Regions (0) Abstract: New multifold seismic reflection data from the Coso geothermal field in the central Coso Range, eastern California, image brittle faults and other structures in a zone of localized crustal extension between two major strike-slip faults. The Coso Wash fault, a Quaternary-active normal fault that is a locus of surface geothermal activity, is well-imaged as a

85

Hydrogen-Assisted Fracture: Materials Testing and Variables Governing Fracture  

NLE Websites -- All DOE Office Websites (Extended Search)

Hydrogen-Assisted Fracture: Materials Hydrogen-Assisted Fracture: Materials Testing and Variables Governing Fracture Brian Somerday, Chris San Marchi, and Dorian Balch Sandia National Laboratories Livermore, CA Hydrogen Pipeline Working Group Workshop Augusta, GA August 30-31, 2005 SNL has 40+ years experience with effects of high-pressure hydrogen gas on materials * Design and maintenance of welded stainless steel pressure vessels for containment of high-pressure H 2 isotopes - Extensive testing of stainless steels exposed to high-pressure H 2 gas * Six-year program in 1970s focused on feasibility of using natural gas pipeline network for H 2 gas - Materials testing in high-pressure H 2 gas using laboratory specimens and model pipeline - Examined fusion zone and heat affected zones of welds * Active SNL staff have authored 70+ papers and organized 6

86

Hydraulic Fracturing (Vermont)  

Energy.gov (U.S. Department of Energy (DOE))

Vermont prohibits hydraulic fracturing or the collection, storage, or treatment of wastewater from hydraulic fracturing

87

Fault and joint geometry at Raft River geothermal area, Idaho | Open Energy  

Open Energy Info (EERE)

and joint geometry at Raft River geothermal area, Idaho and joint geometry at Raft River geothermal area, Idaho Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Report: Fault and joint geometry at Raft River geothermal area, Idaho Details Activities (1) Areas (1) Regions (0) Abstract: Raft River geothermal reservoir is formed by fractures in sedimentary strata of the Miocene and Pliocene Salt Lake Formation. The fracturing is most intense at the base of the Salt Lake Formation, along a decollement that dips eastward at less than 5 0 on top of metamorphosed Precambrian and Lower Paleozoic rocks. Core taken from less than 200 m above the decollement contains two sets of normal faults. The major set of faults dips between 50 0 and 70 0. These faults occur as conjugate pairs that are bisected by vertical extension fractures. The second set of faults

88

Effects of burial history, rock ductility and recovery magnitude on inversion of normal faulted strata  

E-Print Network (OSTI)

Inversion of normal faults at different burial depths is studied using physical models constructed with rock and deformed at confining pressure. Models consist of a 1 cm thick limestone layer above a fault dipping 70° in a rigid medium, and are subjected to a two-stage deformation path of layer-parallel extension followed by coaxial contraction. To investigate the effects of burial depth and relative ductility on kinematics of inversion, five model suites were run in which confining pressure and recovery magnitudes were varied. In all models, a normal fault forms in the limestone during extension. Subsequent inversion is accommodated in the limestone by reverse slip on the normal fault, creation and movement along new reverse faults, and distributed fracturing and folding. The relative contribution of these mechanisms depends on the relative ductility of the rock and magnitude of inversion. Reverse slip on the normal fault and distributed fracturing occur during early stages of inversion and new reverse faults form at intermediate stages. During late stage inversion, strata with low mean ductility shorten primarily by reverse slip on the pre-existing normal fault, whereas strata with high mean ductility shorten by continued slip on reverse faults. Evidence for inversion is provided by superposed fracture fabrics in the footwall at early stages (100% recovery). This change in fracture fabric during inversion could lead to an overpressured footwall in natural inversion structures. Reverse reactivation of the normal faults may occur during coaxial contraction even though such faults are unfavorably oriented assuming typical rock friction behavior and a homogeneous stress state. Localized reverse slip on normal faults is favored when strata display low ductility and less favored when strata work-harden during extension, however, the models show that the final inversion geometry is dependent on the ductility during both phases of deformation. Even a fault that is work-hardened during extension can reactivate if the ductility during contraction is low enough.

Kuhle, Nathan John

2001-01-01T23:59:59.000Z

89

Definition: Accommodation Zone | Open Energy Information  

Open Energy Info (EERE)

Definition Definition Edit with form History Facebook icon Twitter icon » Definition: Accommodation Zone Jump to: navigation, search Dictionary.png Accommodation Zone Accommodation zones occur at fault intersections consisting of belts of interlocking, oppositely dipping normal faults. Multiple subsurface fault intersections in these zones are a favorable host for geothermal activity.[2] View on Wikipedia Wikipedia Definition References ↑ James E. Faulds,Nicholas H. Hinz,Mark F. Coolbaugh,Patricia H. Cashman,Christopher Kratt,Gregory Dering,Joel Edwards,Brett Mayhew,Holly McLachlan. 2011. Assessment of Favorable Structural Settings of Geothermal Systems in the Great Basin, Western USA. In: Transactions. GRC Anual Meeting; 2011/10/23; San Diego, CA. Davis, CA: Geothermal Resources

90

Evolution of the conceptual model of unsaturated zone hydrology at yucca mountain, nevada  

SciTech Connect

Yucca Mountain is an arid site proposed for consideration as the United States' first underground high-level radioactive waste repository. Low rainfall (approximately 170 mm/yr) and a thick unsaturated zone (500-1000 m) are important physical attributes of the site because the quantity of water likely to reach the waste and the paths and rates of movement of the water to the saturated zone under future climates would be major factors in controlling the concentrations and times of arrival of radionuclides at the surrounding accessible environment. The framework for understanding the hydrologic processes that occur at this site and that control how quickly water will penetrate through the unsaturated zone to the water table has evolved during the past 15 yr. Early conceptual models assumed that very small volumes of water infiltrated into the bedrock (0.5-4.5 mm/yr, or 2-3 percent of rainfall), that much of the infiltrated water flowed laterally within the upper nonwelded units because o f capillary barrier effects, and that the remaining water flowed down faults with a small amount flowing through the matrix of the lower welded, fractured rocks. It was believed that the matrix had to be saturated for fractures to show. However, accumulating evidence indicated that infiltration rates were higher than initially estimated, such as infiltration modeling based on neutron borehole data, bomb-pulse isotopes deep in the mountain, perched water analyses and thermal analyses. Mechanisms supporting lateral diversion did not apply at these higher fluxes, and the flux calculated in the lower welded unit exceeded the conductivity of the matrix, implying vertical flow of water into the high permeability fractures of the potential repository host rock, and disequilibrium between matrix and fracture water potentials. The development of numerical modeling methods and parameter values evolved concurrently with the conceptual model in order to account for the observed field data, particularly fracture flow deep in the unsaturated zone. This paper presents the history of the evolution of conceptual models of hydrology and numerical models of unsaturated zone flow at Yucca Mountain, Nevada (Flint, A.L., Flint, L.E., Kwicklis, E.M., Bodvarsson, G.S., Fabryka-Martin, J.M., 2001. Hydrology of Yucca Mountain. Reviews of Geophysics in press). This retrospective is the basis for recommendations for optimizing the efficiency with which a viable and robust conceptual model can be developed for a complex site. (C) 2001 Elsevier Science B.V. All rights reserved. [References: 87

Flint, A. L.; Flint, L. E.; Bodvarsson, G. S.; Kwicklis, E. M.; Fabryka-Martin, J.

2001-02-01T23:59:59.000Z

91

Timing of late Quaternary faulting in the 1954 Dixie Valley earthquake area, central Nevada  

Science Conference Proceedings (OSTI)

The 1954 Dixie Valley earthquake (M 6.9) in central Nevada produced about 3 m of total vertical displacement distributed across two principal fault zones along the east flank of the Stillwater Range. Most of the 1954 displacement was along the range-front fault with minor amounts on the piedmont fault zone, in contrast to an earlier Holocene displacement that was restricted to the piedmont fault. Detailed chronostratigraphic, exploratory drilling, and trenching studies indicate that faulting events have migrated back and forth between the range-front and piedmont fault zones in the late Quaternary. Prior to the 1954 earthquake, the range-front fault last ruptured in the late Pleistocene, during a large-magnitude event here called the IXL event. The northern half of the piedmont fault zone last ruptured between 1.5 and 6.8 ka during a large-magnitude event here called the Bend event. On the basis of 6 m total slip since the deposition of shoreline gravels at {approximately} 12 ka, the estimated Holocene vertical-slip rate is 0.5 mm/yr for the Dixie Valley rupture zone. Overlapping and migratory patterns of late Quaternary faulting indicate that the Dixie Valley zone does not fit a simple segmentation model.

Bell, J.W. (Univ. of Nevada, Reno (USA)); Katzer, T. (Las Vegas Valley Water District, NV (USA))

1990-07-01T23:59:59.000Z

92

MICRO-SEISMICITY, FAULT STRUCTURE AND HYDRAULIC COMPARTMENTALIZATION WITHIN  

Open Energy Info (EERE)

MICRO-SEISMICITY, FAULT STRUCTURE AND HYDRAULIC COMPARTMENTALIZATION WITHIN MICRO-SEISMICITY, FAULT STRUCTURE AND HYDRAULIC COMPARTMENTALIZATION WITHIN THE COSO GETHERMAL FIELD, CALIFORNIA Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Conference Proceedings: MICRO-SEISMICITY, FAULT STRUCTURE AND HYDRAULIC COMPARTMENTALIZATION WITHIN THE COSO GETHERMAL FIELD, CALIFORNIA Details Activities (1) Areas (1) Regions (0) Abstract: High precision earthquake locations and subsurface velocity structure provide potential insights into fracture system geometry, fluid conduits and fluid compartmentalization critical to geothermal reservoir management. We analyze 16 years of seismicity to improve hypocentral locations and simultaneously invert for the seismic velocity structure within the Coso Geothermal Field (CGF). The CGF has been continuously

93

Logs and paleoseismic interpretations from trenches 14C and 14D on the Bow Ridge fault, northeastern Yucca Mountain, Nye County, Nevada  

Science Conference Proceedings (OSTI)

Detailed studies of trenches 14D and 14C on the Bow Ridge fault indicate two to three displacements and long recurrence intervals during the middle to late Quaternary. The main trace of the fault is marked by a thick (20--40 centimeters wide) subvertical shear zone coated with multiple carbonate-silica laminae and several generations of fine-grained fissure-fill debris. Exposed in the trenches is a vertically stacked sequence of thin (0.3--1.5 meters thick) fine-grained colluvial, alluvial, and eolian deposits that commonly contain smaller wedge-shaped units or several weakly to strongly developed buried paleosols, or both. The two to three surface-rupture events are recognized at discrete stratigraphic intervals in the sequence based on (1) incremental up-section decreases in offset of marker horizons, (b) upward terminations of shear zones, fissure fills, and fractures, and (c) the position of small scarp-derived colluvial wedges deposited adjacent to the fault above downfaulted marker horizons. Preferred estimates of the vertical displacement per event are 12 and 40 centimeters. Left-oblique striations are observed on carbonate fault laminae, which, if tectonic in origin, increase the vertical displacement by factors of 1.1 to 1.7, yielding preferred net slip displacements per event of 13 to 70 centimeters. Thermoluminescence ages of 48 {+-} 20 and 132 {+-} 23 thousand years bracket the ages of the events, which probably occurred near the bounding ages of the time interval. These age constraints suggest long, average recurrence intervals between the three events of 75 to 210 ky; the preferred values range between 100 to 140 ky. The small net cumulative displacement of two dated reference horizons yield very low fault slip rates of 0.002 to 0.007 millimeters per year; the preferred value is 0.003 millimeters per year.

Menges, C.M.; Taylor, E.M.; Vadurro, G.; Oswald, J.A.; Cress, R.; Murray, M.; Lundstrom, S.C.; Paces, J.B.; Mahan, S.A.

1997-12-31T23:59:59.000Z

94

Transient fault modeling and fault injection simulation  

E-Print Network (OSTI)

An accurate transient fault model is presented in this thesis. A 7-term exponential current upset model is derived from the results of a device-level, 3-dimensional, single-event-upset simulation. A curve-fitting algorithm is used to extract the numerical model from the empirical data. The model is implemented in a HSPICE simulation environment as a current-injection source for fault simulation. The current transient model is used to conduct electrical-level fault injection simulations on a static RAM cell and subcircuits from two commercial microprocessors. The results from the 7-term exponential model are compared with the results from the widely accepted double-exponential transient model. The experimental data indicate that, for a given charge level, the 7-term exponential fault model results in a higher chance of having a latch error. More importantly, different latch-error patterns are captured from the target circuits under the new fault model.

Yuan, Xuejun

1996-01-01T23:59:59.000Z

95

Active Faulting in the Coso Geothermal Field, Eastern California | Open  

Open Energy Info (EERE)

Faulting in the Coso Geothermal Field, Eastern California Faulting in the Coso Geothermal Field, Eastern California Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Conference Proceedings: Active Faulting in the Coso Geothermal Field, Eastern California Details Activities (1) Areas (1) Regions (0) Abstract: New mapping documents a series of late Quaternary NNE-striking normal faults in the central Coso Range that dip northwest, toward and into the main production area of the Coso geothermal field. The faults exhibit geomorphic features characteristic of Holocene activity, and locally are associated with fumaroles and hydothermal alteration. The active faults sole into or terminate against the brittle-ductile transition zone (BDT) at a depth of about 4 to 5 km. The BDT is arched upward over a volume of crust

96

Incorporating Rigorous Height Determination into Unified Fracture Design  

E-Print Network (OSTI)

Hydraulic fracturing plays an important role in increasing production rate in tight reservoirs. The performance of the reservoir after fracturing can be observed from the productivity index. This parameter is dependent on the fracture geometry; height, length and width. Unified fracture design (UFD) offers a method to determine the fracture dimensions providing the maximum productivity index for a specific proppant amount. Then, in order to achieve the maximum productivity index, the treatment schedules including the amount of liquid and proppant used for each stage must be determined according to the fracture dimensions obtained from the UFD. The proppant number is necessary for determining the fracture geometry using the UFD. This number is used to find the maximum productivity index for a given proppant amount. Then, the dimensionless fracture conductivity index corresponding to the maximum productivity index can be computed. The penetration ration, the fracture length, and the propped fracture width can be computed from the dimensionless fracture conductivity. However, calculating the proppant number used in UFD requires the fracture height as an input. The most convenient way to estimate fracture height to input to the UFD is to assume that the fracture height is restricted by stress contrast between the pay zone and over and under-lying layers. In other words, the fracture height is assumed to be constant, independent of net pressure and equal to the thickness of the layer which has the least minimum principal stress. However, in reality, the fracture may grow out from the target formation and the height of fracture is dependent on the net pressure during the treatment. Therefore, it is necessary to couple determination of the fracture height with determination of the other fracture parameters. In this research, equilibrium height theory is applied to rigorously determine the height of fracture. Solving the problem iteratively, it is possible to incorporate the rigorous fracture height determination into the unified fracture design.

Pitakbunkate, Termpan

2010-08-01T23:59:59.000Z

97

Recurrent faulting and petroleum accumulation, Cat Creek Anticline, central Montana  

SciTech Connect

The Cat Creek anticline, scene of central Montana's first significant oil discovery, is underlain by a south-dipping high-angle fault (Cat Creek fault) that has undergone several episodes of movement with opposite sense of displacement. Borehole data suggest that the Cat Creek fault originated as a normal fault during Proterozoic rifting concurrent with deposition of the Belt Supergroup. Reverse faulting took place in Late Cambrian time, and again near the end of the Devonian Period. The Devonian episode, coeval with the Antler orogeny, raised the southern block several hundred feet. The southern block remained high through Meramecian time, then began to subside. Post-Atokan, pre-Middle Jurassic normal faulting lowered the southern block as much as 1,500 ft. During the Laramide orogeny (latest Cretaceous-Eocene) the Cat Creek fault underwent as much as 4,000 ft of reverse displacement and a comparable amount of left-lateral displacement. The Cat Creek anticline is a fault-propagation fold; en echelon domes and listric normal faults developed along its crest in response to wrenching. Oil was generated mainly in organic-rich shales of the Heath Formation (upper Chesterian Series) and migrated upward along tectonic fractures into Pennsylvanian, Jurassic, and Cretaceous reservoir rocks in structural traps in en echelon domes. Production has been achieved only from those domes where structural closure was retained from Jurassic through Holocene time.

Nelson, W.J. (Illinois State Geological Survey, Champaign (United States))

1991-06-01T23:59:59.000Z

98

A core-based assessment of the spatial relationship of small faults associated with a basement-controlled, large normal fault in the Hickory Sandstone  

E-Print Network (OSTI)

This research characterized a system of small faults (displacement < 0.3 m) in seven closely-spaced continuous 2.4 inch (6.1 cm) diameter cores. Cores were obtained from central Texas, on the western edge of the Llano Uplift. Cores penetrate a dip-slip dominant, normal fault (Nobles Fault) with 18.3 m (60 ft) of stratigraphic throw. The spatial, geometric and kinematic attributes of small faults within the Nobles Fault system were characterized to explore potential cause-and-effect relationships. To quantify spatial distributions, a "density" measure based on individual small fault magnitude was utilized. Approximately half of the small faults in the core possessed no discernible offset markers; thus displacement amount for these faults could not be measured directly. Using a nonparametric method in which an alternating conditional expectation determined optimal transformations for the data, a statistically significant empirical correlation was established for faults with measurable gouge thickness, displacement, protolith mean grain size and sorting. Gouge thickness of small faults was found to be dependant upon the displacement amount of the small fault and the textural characteristics of the host protolith. The role of protolith lithology, proximity to crystalline basement, and structural position relative to the Nobles Fault system were examined to explain observed ubiquitous spatial distribution of small faults. Small faults were found to occur in clusters and the number of faults per foot only weakly correlates to the cumulative displacement of the corresponding faults. The amount of mudstone present is the dominant factor controlling small fault formation. Intervals with only minor quantities of mudstone have the largest number of faults per foot as well as largest associated cumulative displacement per foot. Frequency of occurrence of small faults near the basement is greater when compared to similar lithologies higher in the core. Intensity of small faults do not universally increase with proximity to large faults. To observe an increase in small faults, it is necessary to use a mean global cumulative displacement approach. Zones of greater than average cumulative displacement of small faults in close proximity to large faults were observed in zones that are compatible with faultfault interaction.

Graff, Mitchell C

2006-08-01T23:59:59.000Z

99

Reservoir Fracturing in the Geysers Hydrothermal System: Fact or Fallacy?  

DOE Green Energy (OSTI)

Proper application of proven worldwide fracture determination analyses adequately aids in the detection and enhanced exploitation of reservoir fractures in The Geysers steam field. Obsolete, superficial ideas concerning fracturing in this resource have guided various malformed judgements of the actual elusive trends. Utilizing regional/local tectonics with theoretical rack mechanics and drilling statistics, offers the most favorable method of fracture comprehension. Exploitation philosophies should favor lateral drilling trends along local tensional components and under specific profound drainage/faulting manifestations to enhance high productivities. Drill core observations demonstrate various degrees of fracture filling, brecciation, strain responses, and rock fracture properties, giving the most favorable impression of subsurface reservoir conditions. Considerably more work utilizing current fracturing principles and geologic thought is required to adequately comprehend and economically exploit this huge complex resource.

Hebein, Jeffrey J.

1986-01-21T23:59:59.000Z

100

Hydraulic fracturing-1  

Science Conference Proceedings (OSTI)

This book contains papers on hydraulic fracturing. Topics covered include: An overview of recent advances in hydraulic fracturing technology; Containment of massive hydraulic fracture; and Fracturing with a high-strength proppant.

Not Available

1990-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "fracture zones faults" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


101

Fracture detection and mapping  

DOE Green Energy (OSTI)

Because the costs of drilling, completing, and testing a well can be extremely high, it is important to develop better tools and methods for locating high permeability zones prior to drilling, and to develop better tools and methods for identifying and characterizing major fracture zones during the drilling and well testing stages. At the recommendation of the LBL Industry Review Panel on Geothermal Reservoir Technology, we organized and convened a one-day workshop this past July to discuss various aspects of DOE's current and planned activities in fracture detection, to review the geothermal industry's near-term and long-term research needs, to determine the priority of those needs, to disseminate to industry the status of research in progress, and to discuss the possibility of future joint research between industry and DOE. In this paper we present a brief overview of the workshop from the perspective of those who participated in it and provided us with written comments to a questionnaire that was distributed.

Goldstein, N.E.; Iovenitti, J.L.

1986-03-01T23:59:59.000Z

102

Paleoseismology of latest Pleistocene and Holocene fault activity in central Oregon  

SciTech Connect

Latest Pleistocene and Holocene fault activity in Oregon concentrates along four zones that splay northward from seismically active faults along the Central Nevada and Eastern California seismic zones. The Central Oregon fault zone is one of these zones, which splays northward from dextral faults of the Walker Lane, stretching across the flanks of several ranges in south-central Oregon along a N20[degree]W trend, and ultimately merges with the Cascade volcanic arc near Newberry volcano. Aerial-photo interpretations and field investigations reveal fault scarps with, on average about 4 m, but in places as much as [approximately]10 m of vertical expression across latest Pleistocene pluvial lake deposits and geomorphic surfaces. Trenches across three different faults in the Central Oregon zone reveal evidence for multiple episodes of faulting in the form of fault-related colluvial deposits and deformed horizons which have been cut by younger fault movements. Trench exposures reveal faults with relatively steep dips and anastomosing traces, which are interpreted locally as evidence for a small oblique-slip component. Vertical offsets measured in the trenches are [approximately]2 m or more for each event. Radiocarbon analyses and preliminary tephra correlations indicate that the exposed deposits are [approximately]30,000 yr in age and younger, and record the decline of latest Pleistocene pluvial lakes. Commonly, reworked or deformed lacustrine deposits and interlayered and faulted colluvial deposits mark the second and third events back, which probably occurred in the Latest Pleistocene, at a time during low to moderate lake levels. If offsets of the past 18,000 yr are representative of the long-term average, then faults along this zone have slip rates of from 0.2 mm/yr to 0.6 mm/yr and recurrence intervals that range from [approximately]4,000 yr to 11,000 yr.

Pezzopane, S.K.; Weldon, R.J. II (Univ. of Oregon, Eugene, OR (United States). Dept. of Geological Sciences)

1993-04-01T23:59:59.000Z

103

Fault Current Limiters  

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

Fault Fault Current Limiters Superconducting & Solid-state Power Equipment Office of Electricity Delivery and Energy Reliability www.oe.energy.gov Office of Electricity Delivery and Energy Reliability, OE-1 U.S. Department of Energy - 1000 Independence Avenue, SW - Washington, DC 20585 Plugging America Into the Future of Power What are FCLs? A fault is an unintentional short circuit, or partial short-circuit, in an electric circuit. A variety of factors such as lightning, downed power lines, or crossed power lines cause faults. During a fault, excessive current-called fault current- flows through the electrical system often resulting in a failure of one section of that system by causing a

104

Predicting the occurrence of open natural fractures in shale reservoirs  

SciTech Connect

Prolific oil and gas production has been established from naturally fractured shale reservoirs. For example, in the last few years over 4 Tcf of gas reserves have been established within the self-sourcing Antrim Shale of the Michigan Basin. Historically, locating subsurface fracture systems essential for commercial production has proven elusive and costly. An integrated exploration approach utilizing available geologic, geophysical, and remote sensing data has successfully located naturally fractured zones within the Antrim Shale. It is believed that fracturing of the Antrim shale was a result of basement involved tectonic processes. Characteristic integrated stacked signatures of known fracture systems within the Antrim were built using gravity and magnetic data, structure maps, fracture identification logs, and Landsat imagery. Wireline fracture logs pinpointed the locations and geometries of subsurface fracture systems. Landsat imagery was interpreted to reveal surficial manifestations of subsurface structures.

Decker, A.D.; Klawitter, A.L. (Advanced Resources International, Denver, CO (United States))

1996-01-01T23:59:59.000Z

105

Corporation Commission Hydraulic FracturingHydraulic Fracturing  

E-Print Network (OSTI)

Corporation Commission Hydraulic FracturingHydraulic Fracturing Joint Committee on Energy Commission What is Hydraulic Fracturing d H D It W k?and How Does It Work? · Stimulates a well to increase by Stanolind Oil Company. 2 #12;Kansas Corporation Commission Are Hydraulic Fracture Jobs Performed in Kansas

Peterson, Blake R.

106

An accelerated zone 2 trip algorithm for non-pilot distance relays  

Science Conference Proceedings (OSTI)

This paper presents an algorithm able to accelerate the zone 2 trip of non-pilot distance relays by detecting remote breaker operation following a zone 2 fault. It is based on monitoring changes in proposed composite signals. The performance of the proposed ... Keywords: accelerated trip (AT), real time digital simulator (RTDS), sequential accelerated trip (SAT), total fault clearing time (TFCT)

German Rosas Ortiz; Tarlochan S. Sidhu

2007-05-01T23:59:59.000Z

107

Enhancing in situ bioremediation with pneumatic fracturing  

Science Conference Proceedings (OSTI)

A major technical obstacle affecting the application of in situ bioremediation is the effective distribution of nutrients to the subsurface media. Pneumatic fracturing can increase the permeability of subsurface formations through the injection of high pressure air to create horizontal fracture planes, thus enhancing macro-scale mass-transfer processes. Pneumatic fracturing technology was demonstrated at two field sites at Tinker Air Force Base, Oklahoma City, Oklahoma. Tests were performed to increase the permeability for more effective bioventing, and evaluated the potential to increase permeability and recovery of free product in low permeability soils consisting of fine grain silts, clays, and sedimentary rock. Pneumatic fracturing significantly improved formation permeability by enhancing secondary permeability and by promoting removal of excess soil moisture from the unsaturated zone. Postfracture airflows were 500% to 1,700% higher than prefracture airflows for specific fractured intervals in the formation. This corresponds to an average prefracturing permeability of 0.017 Darcy, increasing to an average of 0.32 Darcy after fracturing. Pneumatic fracturing also increased free-product recovery rates of number 2 fuel from an average of 587 L (155 gal) per month before fracturing to 1,647 L (435 gal) per month after fracturing.

Anderson, D.B.; Peyton, B.M.; Liskowitz, J.L.; Fitzgerald, C.; Schuring, J.R.

1994-04-01T23:59:59.000Z

108

Risking fault seal in the Gulf Coast: A joint industry study  

SciTech Connect

Analysis of more than 200 faults in a joint-industry study of the Gulf Coast provides a database of actual fault seal behavior in producing fields. This empirical database demonstrates that fault seal behavior is predictable rather than random and that faults are more important than is commonly thought in controlling hydrocarbon accumulations. Quantitative fault seal analysis demonstrates that seal behavior is empirically related to the amount of sand and shale incorporated in the fault zone. Faults with sand-rich gouge leak. Faults with shale-rich gouge seal. An empirically defined threshold allows prediction of fault seal behavior with a high degree of confidence. Fewer than 10% of the faults in the Gulf Coast are exceptions to the rule. Exceptions are a result of other factors including low permeability and high displacement pressure sands, and thin-bedded sand/shale sequences. Examples from these Gulf Coast fields demonstrate the fundamental importance of faults in controlling hydrocarbon accumulations. Faults and fault seal behavior control the presence or absence of hydrocarbons, percent fill, hydrocarbon column heights, entrapment of oil versus gas, and high-side and low-side trap risk. Faults control the lateral distribution of hydrocarbon within fault compartments as well as the vertical distribution of hydrocarbon among stacked sands. Faults control fluid flow during both field development and hydrocarbon migration. Bypassed residual accumulations and unnecessary production wells result from neglecting routine fault seal analysis during field development. Dry holes and mistaken reserves assessments result from neglecting routine fault seal analysis during exploration.

Skerlec, G.M. (PetroQuest International Inc., Franklin, PA (United States))

1996-01-01T23:59:59.000Z

109

Regional Analysis And Characterization Of Fractured Aquifers In The  

Open Energy Info (EERE)

Analysis And Characterization Of Fractured Aquifers In The Analysis And Characterization Of Fractured Aquifers In The Virginia Blue Ridge And Piedmont Provinces Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Report: Regional Analysis And Characterization Of Fractured Aquifers In The Virginia Blue Ridge And Piedmont Provinces Details Activities (1) Areas (1) Regions (0) Abstract: Areas related to low-temperature geothermal applications include the recognition of and exploration for deep fracture permeability in crystalline rocks. It is well known that the best currently available downhole techniques to identify the locations of fracture zones in crystalline rocks depend upon the measurement of some thermal parameter such as temperature or heat flow. The temperature-depth profiles and their derivatives provide a direct indication of those fracture zones that

110

Solar system fault detection  

SciTech Connect

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.

Farrington, Robert B. (Wheatridge, CO); Pruett, Jr., James C. (Lakewood, CO)

1986-01-01T23:59:59.000Z

111

Solar system fault detection  

DOE Patents (OSTI)

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.

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

1984-05-14T23:59:59.000Z

112

Analysis of Fault Permeability Using Mapping and Flow Modeling, Hickory Sandstone Aquifer, Central Texas  

Science Conference Proceedings (OSTI)

Reservoir compartments, typical targets for infill well locations, are commonly created by faults that may reduce permeability. A narrow fault may consist of a complex assemblage of deformation elements that result in spatially variable and anisotropic permeabilities. We report on the permeability structure of a km-scale fault sampled through drilling a faulted siliciclastic aquifer in central Texas. Probe and whole-core permeabilities, serial CAT scans, and textural and structural data from the selected core samples are used to understand permeability structure of fault zones and develop predictive models of fault zone permeability. Using numerical flow simulation, it is possible to predict permeability anisotropy associated with faults and evaluate the effect of individual deformation elements in the overall permeability tensor. We found relationships between the permeability of the host rock and those of the highly deformed (HD) fault-elements according to the fault throw. The lateral continuity and predictable permeability of the HD fault elements enhance capability for estimating the effects of subseismic faulting on fluid flow in low-shale reservoirs.

Nieto Camargo, Jorge E., E-mail: jorge.nietocamargo@aramco.com; Jensen, Jerry L., E-mail: jjensen@ucalgary.ca [University of Calgary, Department of Chemical and Petroleum Engineering (Canada)

2012-09-15T23:59:59.000Z

113

Fracture characterization study  

DOE Green Energy (OSTI)

First, the origin, nature, and significance of fractures in general are discussed. Next, discussions are directed toward the designation and classification of fractures. Some typical fracture measurement techniques are discussed. Finally, geothermal fracture systems are investigated and correlations made to determine which fracture technologies from oil field work are applicable to geothermal systems. (MHR)

Kehrman, R.F.

1978-04-01T23:59:59.000Z

114

Fracturing results in diatomaceous earth formations, South Belridge Field, California  

SciTech Connect

The company began fracturing diatomaceous earth zones in the San Joaquin Valley (CA) in 1976. Fracturing has proved an effective method of exploiting these previously noncommercial reservoirs. Nevertheless, productivity behavior is typified by high initial rates followed by rapid decline. Reasons for this decline have been evaluated and are discussed. Also discussed are laboratory experiments performed to determine an appropriate fracture design for this formation.

Strubhar, M.K.; Andreani, F.S.; Medlin, W.L.; Nabi, S.M.

1984-03-01T23:59:59.000Z

115

Explosive fracturing method  

SciTech Connect

A method of inducing a fracture system and multiple cavities in earthen formations is described. A first explosive, preferably nuclear, is buried at a sufficient depth so that its subsequent detonation is fully contained within the earth. Thereafter a second explosive, also preferably nuclear, is buried a predetermined distance from the situs of the first explosive. After detonation of the first explosive, time is allowed to elapse during which the cavity formed by the first explosive collapses to form a rubblized chimney. Thereafter, the second explosive is detonated to create a second chimney parallel to that of the first explosive together with a zone of enhanced permeability between the first and second. (10 claims)

Boardman, C.R.; Knutson, C.F.

1973-12-11T23:59:59.000Z

116

A Thermoelastic Hydraulic Fracture Design Tool for Geothermal Reservoir Development  

DOE Green Energy (OSTI)

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.

Ahmad Ghassemi

2003-06-30T23:59:59.000Z

117

Groundwater penetrating radar and high resolution seismic for locating shallow faults in unconsolidated sediments  

Science Conference Proceedings (OSTI)

Faults in shallow, unconsolidated sediments, particularly in coastal plain settings, are very difficult to discern during subsurface exploration yet have critical impact to groundwater flow, contaminant transport and geotechnical evaluations. This paper presents a case study using cross-over geophysical technologies in an area where shallow faulting is probable and known contamination exists. A comparison is made between Wenner and dipole-dipole resistivity data, ground penetrating radar, and high resolution seismic data. Data from these methods were verified with a cone penetrometer investigation for subsurface lithology and compared to existing monitoring well data. Interpretations from these techniques are compared with actual and theoretical shallow faulting found in the literature. The results of this study suggests that (1) the CPT study, combined with the monitoring well data may suggest that discontinuities in correlatable zones may indicate that faulting is present (2) the addition of the Wenner and dipole-dipole data may further suggest that offset zones exist in the shallow subsurface but not allow specific fault planes or fault stranding to be mapped (3) the high resolution seismic data will image faults to within a few feet of the surface but does not have the resolution to identify the faulting on the scale of our models, however it will suggest locations for upward continuation of faulted zones (4) offset 100 MHz and 200 MHz CMP GPR will image zones and features that may be fault planes and strands similar to our models (5) 300 MHz GPR will image higher resolution features that may suggest the presence of deeper faults and strands, and (6) the combination of all of the tools in this study, particularly the GPR and seismic may allow for the mapping of small scale, shallow faulting in unconsolidated sediments.

Wyatt, D.E. [Westinghouse Savannah River Co., Aiken, SC (United States)]|[South Carolina Univ., Columbia, SC (United States). Earth Sciences and Resources Inst.; Waddell, M.G. [South Carolina Univ., Columbia, SC (United States). Earth Sciences and Resources Inst.; Sexton, B.G. [Microseeps Ltd., Pittsburgh, PA (United States)

1993-12-31T23:59:59.000Z

118

Localization instability and the origin of regularly-spaced faults in planetary lithospheres  

E-Print Network (OSTI)

Brittle deformation is not distributed uniformly in planetary lithospheres but is instead localized on faults and ductile shear zones. In some regions such as the Central Indian Basin or martian ridged plains, localized ...

Montési, Laurent Gilbert Joseph, 1973-

2002-01-01T23:59:59.000Z

119

Optimal fault location  

E-Print Network (OSTI)

Basic goal of power system is to continuously provide electrical energy to the users. Like with any other system, failures in power system can occur. In those situations it is critical that correct remedial actions are applied as soon as possible after the accurate fault condition and location are detected. This thesis has been focusing on automated fault location procedure. Different fault location algorithms, classified according to the spatial placement of physical measurements on single ended, multiple ended and sparse system-wide, are investigated. As outcome of this review, methods are listed as function of different parameters that influence their accuracy. This comparison is than used for generating procedure for optimal fault location algorithm selection. According to available data, and position of the fault with respect to the data, proposed procedure decides between different algorithms and selects an optimal one. A new approach is developed by utilizing different data structures such as binary tree and serialization in order to efficiently implement algorithm decision engine. After accuracy of algorithms is strongly influenced by available input data, different data sources are recommended in proposed architecture such as the digital fault recorders, circuit breaker monitoring, SCADA, power system model and etc. Algorithm for determining faulted section is proposed based on the data from circuit breaker monitoring devices. This algorithm works in real time by recognizing to which sequence of events newly obtained recording belongs. Software prototype of the proposed automated fault location analysis is developed using Java programming language. Fault location analysis is automatically triggered by appearance of new event files in a specific folder. The tests were carried out using the real life transmission system as an example.

Knezev, Maja

2007-12-01T23:59:59.000Z

120

Linear Elastic Fracture Mechanics  

Science Conference Proceedings (OSTI)

..., ASM International, 1996, p 371â??380ASM Handbook, Vol 19, Fatigue And FractureS.D. Antolovich and B.F. Antolovich, An Introduction to Fracture

Note: This page contains sample records for the topic "fracture zones faults" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


121

Advanced hydraulic fracturing methods to create in situ reactive barriers  

Science Conference Proceedings (OSTI)

This article describes the use of hydraulic fracturing to increase permeability in geologic formations where in-situ remedial action of contaminant plumes will be performed. Several in-situ treatment strategies are discussed including the use of hydraulic fracturing to create in situ redox zones for treatment of organics and inorganics. Hydraulic fracturing methods offer a mechanism for the in-situ treatment of gently dipping layers of reactive compounds. Specialized methods using real-time monitoring and a high-energy jet during fracturing allow the form of the fracture to be influenced, such as creation of assymmetric fractures beneath potential sources (i.e. tanks, pits, buildings) that should not be penetrated by boring. Some examples of field applications of this technique such as creating fractures filled with zero-valent iron to reductively dechlorinate halogenated hydrocarbons, and the use of granular activated carbon to adsorb compounds are discussed.

Murdoch, L. [FRX Inc., Cincinnati, OH (United States)]|[Clemson Univ., SC (United States). Dept. of Geological Sciences; Siegrist, B.; Meiggs, T. [Oak Ridge National Lab., TN (United States)] [and others

1997-12-31T23:59:59.000Z

122

Interwell tracer analyses of a hydraulically fractured granitic geothermal reservoir  

DOE Green Energy (OSTI)

Field experiments using fluorescent dye and radioactive tracers (Br{sup 82} and I{sup 131}) have been employed to characterize a hot, low-matrix permeability, hydraulically-fractured granitic reservoir at depths of 2440 to 2960 m (8000 to 9700 ft). Tracer profiles and residence time distributions have been used to delineate changes in the fracture system, particularly in diagnosing pathological flow patterns and in identifying new injection and production zones. The effectiveness of one- and two-dimensional theoretical dispersion models utilizing single and multiple porous, fractured zones with velocity and formation dependent effects are discussed with respect to actual field data.

Tester, J.W.; Potter, R.M.; Bivins, R.L.

1979-01-01T23:59:59.000Z

123

Self-potential observations during hydraulic fracturing  

SciTech Connect

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.

Moore, Jeffrey R.; Glaser, Steven D.

2007-09-13T23:59:59.000Z

124

The Influence of Fold and Fracture Development on Reservoir Behavior of the Lisburne Group of Northern Alaska  

SciTech Connect

The objectives of this study were 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 and lithostratigraphy on fracture patterns, (3) Lithostratigraphy and its influence on folding, faulting, fracturing, and reservoir characteristics, and (4) The influence of lithostratigraphy and deformation on fluid flow.

Wallace, W.K.; Hanks, C.L.; Whalen, M.T.; Jensen, J.; Atkinson, P.K.; Brinton, J.S.

2001-01-09T23:59:59.000Z

125

Interactive fracture design model  

DOE Green Energy (OSTI)

A computer program is described that can be used to design a fracture stimulation treatment for a geothermal reservoir. The program uses state-of-the-art methods to calculate the temperature of the fracture fluid as a function of time and distance in the fracture. This information is used to determine the temperature dependent properties of the fracture fluid. These fluid properties are utilized to calculate the fracture geometry as a function of time. The fracture geometry and temperature distribution of the fracture fluid are coupled so the subroutines that calculate these distributions have been made interactive.

Not Available

1980-05-01T23:59:59.000Z

126

Optimizing reservoir management through fracture modeling  

DOE Green Energy (OSTI)

Fracture flow will become increasingly important to optimal reservoir management as exploration of geothermal reservoirs continues and as injection of spent fluid increases. The Department of Energy conducts research focused on locating and characterizing fractures, modeling the effects of fractures on movement of fluid, solutes, and heat throughout a reservoir, and determining the effects of injection on long-term reservoir production characteristics in order to increase the ability to predict with greater certainty the long-term performance of geothermal reservoirs. Improvements in interpreting and modeling geophysical techniques such as gravity, self potential, and aeromagnetics are yielding new information for the delineation of active major conduits for fluid flow. Vertical seismic profiling and cross-borehole electromagnetic techniques also show promise for delineating fracture zones. DOE funds several efforts for simulating geothermal reservoirs. Lawrence Berkeley Laboratory has adopted a continuum treatment for reservoirs with a fracture component. Idaho National Engineering Laboratory has developed simulation techniques which utilize discrete fractures and interchange of fluid between permeable matrix and fractures. Results of these research projects will be presented to industry through publications and appropriate public meetings. 9 refs.

Renner, J.L.

1988-01-01T23:59:59.000Z

127

Dorchester County- Renewable Zoning  

Energy.gov (U.S. Department of Energy (DOE))

Dorchester County zoning codes specifically permit solar arrays and small wind turbines in many zoning districts.

128

Integration of InSAR and GIS in the Study of Surface Faults Caused by Subsidence-Creep-Fault Processes in Celaya, Guanajuato, Mexico  

Science Conference Proceedings (OSTI)

In Celaya city, Subsidence-Creep-Fault Processes (SCFP) began to become visible at the beginning of the 1980s with the sprouting of the crackings that gave rise to the surface faults 'Oriente' and 'Poniente'. At the present time, the city is being affected by five surface faults that display a preferential NNW-SSE direction, parallel to the regional faulting system 'Taxco-San Miguel de Allende'. In order to study the SCFP in the city, the first step was to obtain a map of surface faults, by integrating in a GIS field survey and an urban city plan. The following step was to create a map of the current phreatic level decline in city with the information of deep wells and using the 'kriging' method in order to obtain a continuous surface. Finally the interferograms maps resulted of an InSAR analysis of 9 SAR images covering the time interval between July 12 of 2003 and May 27 of 2006 were integrated to a GIS. All the maps generated, show how the surface faults divide the city from North to South, in two zones that behave in a different way. The difference of the phreatic level decline between these two zones is 60 m; and the InSAR study revealed that the Western zone practically remains stable, while sinkings between the surface faults 'Oriente' and 'Universidad Pedagogica' are present, as well as in portions NE and SE of the city, all of these sinkings between 7 and 10 cm/year.

Avila-Olivera, Jorge A. [Instituto de Geofisica, Universidad Nacional Autonoma de Mexico, C.U., 04510 Mexico D.F. (Mexico); Instituto de Investigaciones Metalurgicas, Universidad Michoacana de San Nicolas de Hidalgo, C.U., 58030 Morelia, Michoacan (Mexico); Farina, Paolo [Dipartimento di Scienze della Terra, Universita degli Studi di Firenze, Via G. La Pira 4, 50121 Firenze (Italy); Garduno-Monroy, Victor H. [Instituto de Investigaciones Metalurgicas, Universidad Michoacana de San Nicolas de Hidalgo, C.U., 58030 Morelia, Michoacan (Mexico)

2008-05-07T23:59:59.000Z

129

Parallel fault backtracing for calculation of fault coverage  

Science Conference Proceedings (OSTI)

A new improved method for calculation of fault coverage with parallel fault backtracing in combinational circuits is proposed. The method is based on structurally synthesized BDDs (SSBDD) which represent gate-level circuits at higher, macro level where ...

Raimund Ubar; Sergei Devadze; Jaan Raik; Artur Jutman

2008-01-01T23:59:59.000Z

130

Fault Block Kinematics at a Releasing Stepover of the Eastern California  

Open Energy Info (EERE)

Fault Block Kinematics at a Releasing Stepover of the Eastern California Fault Block Kinematics at a Releasing Stepover of the Eastern California Shear Zone: Partitioning of Rotation Style in and Around the Coso Geothermal Area and Nascent Metamorphic Core Complex Jump to: navigation, search OpenEI Reference LibraryAdd to library Journal Article: Fault Block Kinematics at a Releasing Stepover of the Eastern California Shear Zone: Partitioning of Rotation Style in and Around the Coso Geothermal Area and Nascent Metamorphic Core Complex Abstract Pliocene lavas and sediments of Wild Horse Mesa in the Coso Range, CA exhibit clockwise vertical-axis rotation of fault-bounded blocks. This indicates localization of one strand of the Eastern California shear zone/Walker Lane Belt within a large-scale, transtensional, dextral, releasing stepover. We measured rotations paleomagnetically relative to two

131

Modeling of coulpled deformation and permeability evolution during fault reactivation induced by deep underground injection of CO2  

Science Conference Proceedings (OSTI)

The interaction between mechanical deformation and fluid flow in fault zones gives rise to a host of coupled hydromechanical processes fundamental to fault instability, induced seismicity, and associated fluid migration. In this paper, we discuss these coupled processes in general and describe three modeling approaches that have been considered to analyze fluid flow and stress coupling in fault-instability processes. First, fault hydromechanical models were tested to investigate fault behavior using different mechanical modeling approaches, including slip interface and finite-thickness elements with isotropic or anisotropic elasto-plastic constitutive models. The results of this investigation showed that fault hydromechanical behavior can be appropriately represented with the least complex alternative, using a finite-thickness element and isotropic plasticity. We utilized this pragmatic approach coupled with a strain-permeability model to study hydromechanical effects on fault instability during deep underground injection of CO{sub 2}. We demonstrated how such a modeling approach can be applied to determine the likelihood of fault reactivation and to estimate the associated loss of CO{sub 2} from the injection zone. It is shown that shear-enhanced permeability initiated where the fault intersects the injection zone plays an important role in propagating fault instability and permeability enhancement through the overlying caprock.

Cappa, F.; Rutqvist, J.

2010-06-01T23:59:59.000Z

132

DIFFERENTIAL FAULT SENSING CIRCUIT  

DOE Patents (OSTI)

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.

Roberts, J.H.

1961-09-01T23:59:59.000Z

133

Computer hardware fault administration  

DOE Patents (OSTI)

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.

Archer, Charles J. (Rochester, MN); Megerian, Mark G. (Rochester, MN); Ratterman, Joseph D. (Rochester, MN); Smith, Brian E. (Rochester, MN)

2010-09-14T23:59:59.000Z

134

Mapping Fractures In The Medicine Lake Geothermal System | Open Energy  

Open Energy Info (EERE)

Fractures In The Medicine Lake Geothermal System Fractures In The Medicine Lake Geothermal System Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Conference Paper: Mapping Fractures In The Medicine Lake Geothermal System Details Activities (1) Areas (1) Regions (0) Abstract: A major challenge to energy production in the region has been locating high-permability fracture zones in the largely impermeable volcanic host rock. An understanding of the fracture networks will be a key to harnessing geothermal resources in the Cascades Author(s): Steven Clausen, Michal Nemcok, Joseph Moore, Jeffrey Hulen, John Bartley Published: GRC, 2006 Document Number: Unavailable DOI: Unavailable Core Analysis At Medicine Lake Area (Clausen Et Al, 2006) Medicine Lake Geothermal Area Retrieved from "http://en.openei.org/w/index.php?title=Mapping_Fractures_In_The_Medicine_Lake_Geothermal_System&oldid=388927

135

Student Zone  

NLE Websites -- All DOE Office Websites (Extended Search)

Student Zone Student Zone Homework Helpers All About Atoms - Learn about the parts of the atom! Virginia State Standards of Learning Practice Tests - Practice taking the SOL tests! Subjects currently include algebra, math, science and technology. Table of Elements - Basic physical and historical information about the elements! [Printable Version] Questions and Answers - Have a question? Need an answer? Check here first! Glossary of Science Terms - Definitions of some of the terms used on this site. Jefferson Lab Virtual Tour - How do scientists explore inside atoms? Video Resources Frostbite Theater - Short science experiments using liquid nitrogen, static electricity and more! Physics Out Loud - Jefferson Lab scientists and other experts explain some of the common words and terms used in nuclear physics research.

136

Controls on Fault-Hosted Fluid Flow: Preliminary Results from the Coso  

Open Energy Info (EERE)

Controls on Fault-Hosted Fluid Flow: Preliminary Results from the Coso Controls on Fault-Hosted Fluid Flow: Preliminary Results from the Coso Geothermal Field, CA Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Conference Proceedings: Controls on Fault-Hosted Fluid Flow: Preliminary Results from the Coso Geothermal Field, CA Details Activities (1) Areas (1) Regions (0) Abstract: cap rock, permeability, fault, fracture, clay, Coso Author(s): Davatzes, N.C.; Hickman, S.H. Published: Geothermal Resource Council Transactions 2005, 1/1/2005 Document Number: Unavailable DOI: Unavailable Conceptual Model At Coso Geothermal Area (2005-2007) Coso Geothermal Area Retrieved from "http://en.openei.org/w/index.php?title=Controls_on_Fault-Hosted_Fluid_Flow:_Preliminary_Results_from_the_Coso_Geothermal_Field,_CA&oldid=473359"

137

Dynamic Fault Detection Chassis  

Science Conference Proceedings (OSTI)

Abstract The high frequency switching megawatt-class High Voltage Converter Modulator (HVCM) developed by Los Alamos National Laboratory for the Oak Ridge National Laboratory's Spallation Neutron Source (SNS) is now in operation. One of the major problems with the modulator systems is shoot-thru conditions that can occur in a IGBTs H-bridge topology resulting in large fault currents and device failure in a few microseconds. The Dynamic Fault Detection Chassis (DFDC) is a fault monitoring system; it monitors transformer flux saturation using a window comparator and dV/dt events on the cathode voltage caused by any abnormality such as capacitor breakdown, transformer primary turns shorts, or dielectric breakdown between the transformer primary and secondary. If faults are detected, the DFDC will inhibit the IGBT gate drives and shut the system down, significantly reducing the possibility of a shoot-thru condition or other equipment damaging events. In this paper, we will present system integration considerations, performance characteristics of the DFDC, and discuss its ability to significantly reduce costly down time for the entire facility.

Mize, Jeffery J [ORNL

2007-01-01T23:59:59.000Z

138

Field Mapping At Central Nevada Seismic Zone Region (Shevenell, Et Al.,  

Open Energy Info (EERE)

Shevenell, Et Al., Shevenell, Et Al., 2008) Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Exploration Activity: Field Mapping At Central Nevada Seismic Zone Region (Shevenell, Et Al., 2008) Exploration Activity Details Location Central Nevada Seismic Zone Geothermal Region Exploration Technique Field Mapping Activity Date Usefulness could be useful with more improvements DOE-funding Unknown Notes On a more local scale, Faulds et al. (2003, 2005a, 2005b, 2006) have conducted structural analysis and detailed geologic mapping at a number of sites throughout Nevada and have found that productive geothermal systems typically occur in one of several structural settings, including step-overs in normal fault zones, near the ends of major normal faults where the faults break into multiple splays, in belts of overlapping faults, at fault

139

Decreasing Slip Rates From12.8 Ma to Present on the Solitario Canyon Fault at Yucca Mountain, Nevada  

DOE Green Energy (OSTI)

The Solitario Canyon fault, which bounds the west side of Yucca Mountain, Nevada, is the closest fault with Quaternary offset adjacent to the proposed spent nuclear fuel and high-level radioactive waste repository. Dip-slip offset between 12.8 and 10.7 Ma is determined from lithostratigraphic displacement in boreholes USW H-3 and USW WT-7, drilled in the footwall and hanging wall, respectively. The base of the 12.8-Ma Topopah Spring Tuff is interpreted to have 463.3 m of separation across the fault, an average dip slip rate of 0.036 mm/yr. Previous researchers identified a geothermal system active from 11.5 to 10.0 Ma with peak activity at 10.7 Ma that resulted in pervasive alteration of vitric rock to zeolitic minerals where the rocks were in the ground-water saturated zone. The contact between vitric (V) and pervasively zeolitic (Z) rocks cuts across the lithostratigraphic section and offset of this V-Z boundary can be used to measure slip rates between 12.8 and 10.7 Ma. In H-3, the V-Z boundary is 138.4 m below the base of the vitric, densely welded subzone of the Topopah Spring Tuff (Tptpv3). In WT-7, although the V-Z boundary is identified at the base of the Tptpv3, borehole video, cuttings, and geophysical log data indicate the Tptpv3 has well-developed zeolitic alteration along fractures, and this implies 19.5 m of the total thickness of Tptpv3 (and probably additional overlying crystallized rocks) also were in the saturated zone by 10.7 Ma. The V-Z relations across the Solitario Canyon fault in H-3 and WT-7 indicate a minimum of 157.9 m of separation before 10.7 Ma, which is 34.1 percent of the total slip of the Topopah Spring Tuff, and a minimum dip slip rate of 0.075 mm/yr from 12.8 to 10.7 Ma. These data are consistent with the broader structural history of the area near Yucca Mountain. Previous workers used angular unconformities, tilting of structural blocks, and paleomagnetic data to constrain the main period of extensional faulting between 12.7 and 8.5 Ma. Paleoseismic studies in Quaternary deposits documented slip rates on the Solitario Canyon fault from 0.01 to 0.02 mm/yr since 0.077 and 0.20 Ma. The decrease of extensional activity slip rates data on the Solitario Canyon fault provide evidence of decreasing tectonic activity from the middle Miocene to present.

D. Buesch

2006-07-11T23:59:59.000Z

140

Experimental study of fracture development in multilayers of contrasting strength and ductility  

E-Print Network (OSTI)

The effect of mean ductility, interlayer thickness, and magnitude of shortening on fracture development in bedded rock was investigated by shortening multilayer cylinders (5 cm dia.) 4 to 14% normal to layering in a triaxial apparatus. Multilayers were constructed by stacking two 1.4-cm thick layers of Berea Sandstone (relatively strong and brittle) with interlayers of Indiana Limestone (relatively weak and ductile). Thickness of the interlayer between the sandstone was 30%, 100%, or 150% of the thickness of the sandstone layer. Mean ductility was varied by shortening at confining pressures (Pc) of 5, 25, 50, and 100 MPa. Sandstone layers fracture at all conditions. Fractures have preferred orientation symmetric to the cylinder axis, and display systematic spacing. At the lowest Pc and mean ductility, fractures in the sandstone are dominantly opening mode (joints) and mixed mode fractures oriented at high angles to layer boundaries. At greater Pc and mean ductility, fractures are dominantly shear mode (faults) and display conjugate geometry. Average dihedral angle of the conjugates increases from 16 to 67 degrees with increase in mean ductility. Maximum fracture density in the sandstone occurs at intermediate mean ductility and maximum interlayer thickness. Fractures propagate from the sandstone into the limestone and may link across the limestone interlayer as shortening is increased. Linkage is enhanced with decreasing mean ductility and interlayer thickness, and increasing shortening. At high mean ductility, fractures are confined to the sandstone layers. Limestone deforms by faulting and compactive cataclastic flow at low and high mean ductility, respectively. Faults in limestone are more variable in orientation and display larger dihedral angles than in the sandstone. Fracture mode and orientation are consistent with Mohr-Coulomb failure, and a spatially heterogeneous stress state where the most tensile stress occurs in the sandstone. Types of fracture networks in multilayer sequences with moderate ductility contrast vary from joints and faults, refracted faults, to faults and flow with increasing mean ductility. Fracture spacing depends on layer and interlayer thickness, mean ductility and ductility contrast, and magnitude of shortening.

Cubuk, Pelin

2002-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "fracture zones faults" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


141

High velocity impact fracture  

E-Print Network (OSTI)

An in-depth understanding of dynamic ductile fracture is one of the most important steps to improve the survivability of critical structures such as the lost Twin Towers. In the present thesis, the macroscopic fracture ...

Teng, Xiaoqing

2005-01-01T23:59:59.000Z

142

Development of Hydrologic Characterization Technology of Fault Zones  

E-Print Network (OSTI)

~FY2009 1. Field Investigation Conduct field investigationsinformation and conduct surface geologic investigation andat the detailed investigation stage. Conduct comprehensive

Karasaki, Kenzi

2009-01-01T23:59:59.000Z

143

Development of Hydrologic Characterization Technology of Fault Zones  

E-Print Network (OSTI)

113, 51-68. Swedish Nuclear Fuel and Waste Management Co. ,SEPM, 52 p. Swedish Nuclear Fuel and Waste Management Co. ,Disposal of Canada’s Nuclear Fuel Waste. AECL -10711, COG-

Karasaki, Kenzi

2009-01-01T23:59:59.000Z

144

Development of Hydrologic Characterization Technology of Fault Zones  

E-Print Network (OSTI)

transport, and heat transfer processes in porous media.transport, and heat transfer, we assume that these processesprocesses, as described by Equation (4) or (8), as well as heat transfer,

Karasaki, Kenzi

2009-01-01T23:59:59.000Z

145

Development of Hydrologic Characterization Technology of Fault Zones  

E-Print Network (OSTI)

London) Special Publication 148, p. 117-134. Flint, A.L. ,Flint, L.E. , Bodvarsson, G.S. , Kwicklis, E.M. , andVol. 32, No. 9, 825-828, 2004b. Flint, A.L. , Flint, L.E. ,

Karasaki, Kenzi

2009-01-01T23:59:59.000Z

146

Development of Characterization Technology for Fault Zone Hydrology  

E-Print Network (OSTI)

conducted using electrical resistivity survey and seismicWF3 WF2 WF1 TR1 Electrical Resistivity Seismic Reflectionat depth. Four electrical resistivity surveys and three

Karasaki, Kenzi

2010-01-01T23:59:59.000Z

147

The paragenesis chemistry of alteration associated with the P2and fault in metamorphic rocks underlying the Athabasca Basin  

E-Print Network (OSTI)

's largest high-grade uranium deposit. This deposit is classified as unconformity-type because it is located: i) pitchblende at the uranium sMcArthur River deposit, ii) mineral perched within the overlying Zone 2 McArthur River Mine VQ Fault Fault Unconformity U-mineralization Pegmatite Quartzite Arkose

148

Location of hydraulic fractures using microseismic techniques  

DOE Green Energy (OSTI)

Microearthquakes with magnitudes ranging between -6 and -2 have been observed in three successive massive injections of water at the Hot Dry Rock Geothermal Energy demonstration site at Fenton Hill, New Mexico. The injection was part of a program to increase the heat transfer area of hydraulic fractures and to decrease the flow-through impedance between wells. The microearthquakes were used in mapping the location of the extended hydraulic fractures. A downhole triaxial system positioned approximately 200 m vertically above the injection point in a shut-in production well was used for detection. The microearthquakes occurred in a north-northwest striking zone 400 m in length passing through the injection point. During a third substantially larger injection, microearthquakes occurred in a dispersed volume at distances as great as 800 m from the zone active in the first two injections.

Albright, J.A.; Pearson, C.F.

1980-01-01T23:59:59.000Z

149

Characterization of EGS Fracture Network Lifecycles  

DOE Green Energy (OSTI)

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 nation’s 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

Gillian R. Foulger

2008-03-31T23:59:59.000Z

150

A High shear stress segment along the San Andreas Fault: Inferences based on near-field stress direction and stress magnitude observations in the Carrizo Plain Area  

SciTech Connect

Nearly 200 new in-situ determinations of stress directions and stress magnitudes near the Carrizo plain segment of the San Andreas fault indicate a marked change in stress state occurring within 20 km of this principal transform plate boundary. A natural consequence of this stress transition is that if the observed near-field ``fault-oblique`` stress directions are representative of the fault stress state, the Mohr-Coulomb shear stresses resolved on San Andreas sub-parallel planes are substantially greater than previously inferred based on fault-normal compression. Although the directional stress data and near-hydrostatic pore pressures, which exist within 15 km of the fault, support a high shear stress environment near the fault, appealing to elevated pore pressures in the fault zone (Byerlee-Rice Model) merely enhances the likelihood of shear failure. These near-field stress observations raise important questions regarding what previous stress observations have actually been measuring. The ``fault-normal`` stress direction measured out to 70 km from the fault can be interpreted as representing a comparable depth average shear strength of the principal plate boundary. Stress measurements closer to the fault reflect a shallower depth-average representation of the fault zone shear strength. If this is true, only stress observations at fault distances comparable to the seismogenic depth will be representative of the fault zone shear strength. This is consistent with results from dislocation monitoring where there is pronounced shear stress accumulation out to 20 km of the fault as a result of aseismic slip within the lower crust loading the upper locked section. Beyond about 20 km, the shear stress resolved on San Andreas fault-parallel planes becomes negligible. 65 refs., 15 figs.

Castillo, D. A., [Department of Geology and Geophysics, University of Adelaide (Australia); Younker, L.W. [Lawrence Livermore National Lab., CA (United States)

1997-01-30T23:59:59.000Z

151

Fault Current Management Guidebook - Updated  

Science Conference Proceedings (OSTI)

Under the new paradigm of power market operation, electric utilities are forcing more power through the existing transmission lines; and these increased loads will increase the fault current level throughout the power system. Also, new generation sources including distributed generation added at the transmission and distribution network will increase power flows and, consequently, fault current levels. Under increased power flow conditions on the existing assets, managing fault currents is crucial in ord...

2007-12-20T23:59:59.000Z

152

Fault Mapping | Open Energy Information  

Open Energy Info (EERE)

form form View source History View New Pages Recent Changes All Special Pages Semantic Search/Querying Get Involved Help Apps Datasets Community Login | Sign Up Search Page Edit with form History Facebook icon Twitter icon » Fault Mapping Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Exploration Technique: Fault Mapping Details Activities (2) Areas (2) Regions (0) NEPA(0) Exploration Technique Information Exploration Group: Field Techniques Exploration Sub Group: Data Collection and Mapping Parent Exploration Technique: Data Collection and Mapping Information Provided by Technique Lithology: Stratigraphic/Structural: Locates active faults in the area of interest Hydrological: Can reveal whether faults are circulating hydrothermal fluids Thermal: Dictionary.png

153

Self-potential observations during hydraulic fracturing  

E-Print Network (OSTI)

potential measurements during hydraulic fracturing of BunterMonitoring during hydraulic fracturing using the TG-2 well,fracture processes in hydraulic fracturing, Quarterly Report

Moore, Jeffrey R.; Glaser, Steven D.

2008-01-01T23:59:59.000Z

154

Fracturing operations in a dry geothermal reservoir  

DOE Green Energy (OSTI)

Fracturing operations at the Fenton Hill, New Mexico, Hot Dry Rock (HDR) Geothermal Test Site initiated unique developments necessary to solve problems caused by an extremely harsh downhole environment. Two deep wells were drilled to approximately 15,000 ft (4.6 km); formation temperatures are in excess of 600/sup 0/F (315/sup 0/C). The wells were drilled during 1979 to 1981, inclined at 35 degrees, one above the other, and directionally drilled in an azimuthal direction orthogonal to the least principal in-situ crustal stress field. Hydraulic fracturing experiments to connect the two wells have used openhole packers, hydraulic jet notching of the borehole wall, cemented-in insolation liners and casing packers. Problems were encountered with hole drag, high fracture gradients, H/sub 2/S in vent back fluids, stress corrosion cracking of tubulars, and the complex nature of three-dimensional fracture growth that requires very large volumes of injected water. Two fractured zones have been formed by hydraulic fracturing and defined by close-in, borehole deployed, microseismic detectors. Initial operations were focused in the injection wellbore near total depth, where water injection treatments totalling 51,000 bbls (8100 m/sup 3/) were accomplished by pumping through a cemented-in 4-1/2 in. liner/PBR assembly. Retrievable casing packers were used to inject 26,000 bbls (4100 m/sup 3/) in the upper section of the open hole. Surface injection pressures (ISIP) varied from 4000 to 5900 psi (27 to 41 MPa) and the fracture gradient ranged from 0.7 to 0.96 psi/ft.

Rowley, J.C.; Pettitt, R.A.; Hendron, R.H.; Sinclair, A.R.; Nicholson, R.W.

1983-01-01T23:59:59.000Z

155

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

SciTech Connect

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.

Huang, Lianjie [Los Alamos National Laboratory; Albrecht, Michael [TBA Power; Kaufman, Greg [Jemez Purblo; Kelley, Shari [NM Bureau of Geology and Mineral Researces; Rehfeldt, Kenneth [Los Alamos National Laboratory; Zhang, Zhifu [EES-17 visitor

2011-01-01T23:59:59.000Z

156

Design and Implementation of Energized Fracture Treatment in Tight Gas Sands  

SciTech Connect

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.

Mukul Sharma; Kyle Friehauf

2009-12-31T23:59:59.000Z

157

Structural styles of the Wilcox and Frio growth-fault trends in Texas: Constraints on geopressured reservoirs  

DOE Green Energy (OSTI)

The wide variability in structural styles within the growth-faulted, geopressured trends of the Texas Gulf Coast is illustrated by detailed structural maps of selected areas of the Wilcox and Frio growth-fault trends and quantified by statistical analysis of fault compartment geometries. Structural variability is a key determinant of the size of geopressured aquifers in the deep subsurface. Two major structural styles exist in the Wilcox trend. (1) In southeast and Central Texas, the trend consists of continuous, closely spaced faults that have little associated rollover despite moderate expansion of section; the fault plane flattens little with depth. (2) By contrast, in South Texas a narrow band of growth faults having high expansion and moderate rollover lies above and downdip of a ridge of deformed, overpressured shale but updip of a deep basin formed by withdrawal of overpressured shale. Frio fault systems generally display greater rollover and wider spacing than do Wilcox fault systems; however, the Frio trend displays distinctive features in each study area. Most of the Frio growth faults, however, have a similar geometry, showing substantial rollover, expansion of section, and a moderate flattening of the fault zone with depth, possibly related to a deep decollement surface. The local variability in style is related to the magnitude of Frio sedimentation and progradation and to the presence of thick salt or shale. Finding and developing a large geopressured aquifer require recognition of a favorable combination of sand-body geometry, reservoir quality, and fault compartment size and shape.

Ewing, T.E.

1986-01-01T23:59:59.000Z

158

Multiple signal fault detection using fuzzy logic  

Science Conference Proceedings (OSTI)

In this paper, we describe a multiple Signal Fault Detection system that employs fuzzy logic at two levels of detection: signal segment fault and signal fault. The system involves signal segmentation, feature extraction and fuzzy logic based segment ...

Yi Lu Murphey; Jacob Crossman; ZhiHang Chen

2003-06-01T23:59:59.000Z

159

Brittle fracture phenomena: An hypothesis  

SciTech Connect

It is proposed that: volumetric dilation is a fundamental requirement for brittle fracture involving shear; such dilation commonly involves or is expressed as zonal overpressures; the overpressured zones radiate particle motions which are significant to or dominate seismic radiation from blasting; the overpressures are commonly significant to and may dominate the energetics of blastings. Outstanding problems and gaps in our knowledge regarding fragmentation are discussed. It is argued that there is a common missing factor, dilatancy. Supporting evidence is presented from soils and rock mechanics, blasting experimental data and blasting experience. Computer modeling of fragmentation is discussed and the necessity for the inclusion of dilatancy established. Implications are discussed and a test of the hypothesis proposed.

Britton, K.; Walton, O.R.

1987-05-01T23:59:59.000Z

160

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

Science Conference Proceedings (OSTI)

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.

Riha, B

2005-10-31T23:59:59.000Z

Note: This page contains sample records for the topic "fracture zones faults" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


161

Definition: Enhanced Fault Protection | Open Energy Information  

Open Energy Info (EERE)

Enhanced Fault Protection Enhanced Fault Protection Enhanced fault protection requires higher precision and greater discrimination of fault location and type with coordinated measurement among multiple devices. For distribution applications, these systems will detect and isolate faults without full-power re-closing, reducing the frequency of through-fault currents. Using high resolution sensors and fault signatures, these systems can better detect high impedance faults. For transmission applications, these systems will employ high speed communications between multiple elements (e.g., stations) to protect entire regions, rather than just single elements. They will also use the latest digital techniques to advance beyond conventional impedance relaying of transmission lines.[1] Related Terms

162

Definition: Fault Mapping | Open Energy Information  

Open Energy Info (EERE)

Mapping Jump to: navigation, search Dictionary.png Fault Mapping Faults are structural features of crustal rocks that are caused by tectonic forces. These features can create...

163

Hydraulic fracturing of a moderate permeability reservoir, Kuparuk River Unit  

SciTech Connect

Sixty-five percent of the proven reserves in one of the United States' largest oil fields, the Kuparuk River Unit, are contained in the lower of two producing horizons. This zone, commonly referred to as the ''A'' sand, has a permeability of between 30 and 100 md. Unfortunately this interval is easily damaged during drilling and completion operations. Low initial flow efficiencies have been confirmed by numerous pressure transient tests. A program of hydraulic fracturing was initiated in March 1984 to overcome near wellbore damage and provide stimulation to more efficiently tap ''A'' sand reserves. More than 300 fracture stimulations have been completed to date in the arctic setting of the Kuparuk River Unit. These jobs have used a variety of fluids, proppants, and pumping schedules. The current hydraulic fracture design was evolved by continual interpretation of field results and related data from these previous stimulations. Success of the overall program has been impressive. Average post-fracture flow efficiency has been in excess of 100%. Post-fracture rate increase has averaged approximately 300%, accounting for a total rate increase of over 125,000 BOPD (19,900 m/sup 3//d). Based on these results, fracturing will continue to play an important part in future field development. This paper is the first review of the Kuparuk River Unit fracture program. It provides a case history of the development of a standard fracture design. In addition, the findings of this study would be applicable to reservoirs elsewhere with similar characteristics.

Niemeyer, B.L.; Reinart, M.R.

1986-01-01T23:59:59.000Z

164

Modeling the fracture of ice sheets on parallel computers.  

SciTech Connect

The objective of this project is to investigate the complex fracture of ice and understand its role within larger ice sheet simulations and global climate change. 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. Dramatic illustrations of fracture-induced phenomena most notably include the recent collapse of ice shelves in Antarctica (e.g. partial collapse of the Wilkins shelf in March of 2008 and the diminishing extent of the Larsen B shelf from 1998 to 2002). Other fracture examples include ice calving (fracture of icebergs) which is presently approximated in simplistic ways within ice sheet models, and the draining of supraglacial lakes through a complex network of cracks, a so called ice sheet plumbing system, that is believed to cause accelerated ice sheet flows due essentially to lubrication of the contact surface with the ground. These dramatic changes are emblematic of the ongoing change in the Earth's polar regions and highlight the important role of fracturing ice. To model ice fracture, a simulation capability will be designed centered around extended finite elements and solved by specialized multigrid methods on parallel computers. In addition, appropriate dynamic load balancing techniques will be employed to ensure an approximate equal amount of work for each processor.

Waisman, Haim (Columbia University); Bell, Robin (Columbia University); Keyes, David (Columbia University); Boman, Erik Gunnar; Tuminaro, Raymond Stephen

2010-03-01T23:59:59.000Z

165

Technology Zones (Virginia)  

Energy.gov (U.S. Department of Energy (DOE))

Virginia’s 26 designated Technology Zones offer tax relief in the form of abatements, credits, deductions, deferrals, exemptions, or rebates. Local governments may designate technology zones to...

166

Behavior of Late Quaternary and historical faults in the western Basin and Range province  

Science Conference Proceedings (OSTI)

Quaternary stratigraphic relations and exploratory trenching in zones of historical surface faulting in the western Basin and Range Province suggest that faults with historical surface ruptures have similar, and in some cases lower, long-term (late Quaternary) and short-term (Holocene) slip rates than other adjacent and regional non-historical Quaternary faults. In the 1954 Dixie Valley earthquake (M6.8) zone, the range-front and piedmont faults collectively record a late Quaternary (200 ka) slip rate on the order of 0.2 mm/yr and a Holocene (7--12 ka) slip rate of 0.5--0.8 mm/yr. The principal segment of the 1932 Cedar Mountain earthquake (M7.2) zone has an estimated latest Quaternary (25--35 ka) slip rate of 0.2--0.7 mm/yr and a Holocene (6--13 ka) slip rate of 0.3--0.7 mm/yr. The 1954 Rainbow Mountain earthquakes (M6.6 and M6.8) and 1954 Fairview Peak earthquake (M7.1) zones have late Quaternary slip rates that are lower (=] 1 mm/yr. Based on a comparison of Holocene and late Quaternary rates, many, but not all, historical and non-historical zones show evidence of temporal clustering.

Bell, J.W. (Univ. of Nevada, Reno, NV (United States). Nevada Bureau of Mines and Geology)

1993-04-01T23:59:59.000Z

167

Finding Large Aperture Fractures in Geothermal Resource Areas Using a  

Open Energy Info (EERE)

Finding Large Aperture Fractures in Geothermal Resource Areas Using a Finding Large Aperture Fractures in Geothermal Resource Areas Using a Three-Component Long-Offset Surface Seismic Survey Geothermal Project Jump to: navigation, search Last modified on July 22, 2011. Project Title Finding Large Aperture Fractures in Geothermal Resource Areas Using a Three-Component Long-Offset Surface Seismic Survey Project Type / Topic 1 Recovery Act: Geothermal Technologies Program Project Type / Topic 2 Validation of Innovative Exploration Technologies Project Description Because fractures and faults with sub-commercial permeability can propagate hot fluid and hydrothermal alteration throughout a geothermal reservoir, potential field geophysical methods including resistivity, gravity, heatflow and magnetics cannot distinguish between low-permeability fractures and LAF's (Large Aperature Fractures). USG will develop and test the combination of three-component,long-offset seismic surveying, permanent scatter synthetic aperture radar interferometry (PSInSAR) and structural kinematic analysis as an integrated method for locating and 3-D mapping of LAF's in shallow to intermediate depth (600-4000 feet) geothermal systems. This project is designed to test the methodology on known occurrences of LAF's and then apply the technology to expand an existing production field and find a new production field in a separate but related resource area. A full diameter production well will be drilled into each of the two lease blocks covered by the geophysical exploration program.

168

Arc fault detection system  

DOE Patents (OSTI)

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.

Jha, Kamal N. (Bethel Park, PA)

1999-01-01T23:59:59.000Z

169

Arc fault detection system  

DOE Patents (OSTI)

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.

Jha, K.N.

1999-05-18T23:59:59.000Z

170

A Rare Isolated Trapezoid Fracture  

E-Print Network (OSTI)

Toh S, Tsubo K, et al. An occult fracture of the trapezoiddue to concern for an occult fracture revealed a comminuted

Afifi, Negean; Lu, Jenny J

2011-01-01T23:59:59.000Z

171

Hydraulic Fracturing in Particulate Materials .  

E-Print Network (OSTI)

??For more than five decades, hydraulic fracturing has been widely used to enhance oil and gas production. Hydraulic fracturing in solid materials (e.g., rock) has… (more)

Chang, Hong

2004-01-01T23:59:59.000Z

172

Vertical arrays for fracture mapping in geothermal systems  

DOE Green Energy (OSTI)

In collaboration with UNOCAL Geothermal Operations, Los Alamos National Laboratory assessed the feasibility of using vertical arrays of borehole seismic sensors for mapping of microseismicity in The Geysers geothermal field. Seismicity which arises from minute displacements along fracture or fault surfaces has been shown in studies of seismically active oil reservoirs to be useful in identifying fractures affected by and possibly contributing to production. Use of retrievable borehole seismic packages at The Geysers was found to reduce the threshold for detection of microearthquakes by an estimated 2--3 orders of magnitude in comparison to surface-based sensors. These studies led to the design, materials selection, fabrication, and installation of a permanent array of geophones intended for long term seismic monitoring and mapping of fractures in the vicinity of the array at The Geysers.

Albright, J.N. [Los Alamos National Lab., NM (United States); Rutledge, J.T.; Fairbanks, T.D. [Nambe Geophysics, Inc. (United States); Thomson, J.C. [Lithos Inc. (United States); Stevenson, M.A. [Petroleum Geo-Services (United States)

1998-12-01T23:59:59.000Z

173

Observer-based fault detection for nuclear reactors  

E-Print Network (OSTI)

This is a study of fault detection for nuclear reactor systems. Basic concepts are derived from fundamental theories on system observers. Different types of fault- actuator fault, sensor fault, and system dynamics fault ...

Li, Qing, 1972-

2001-01-01T23:59:59.000Z

174

Unsaturated Zone and Saturated Zone Transport Properties (U0100)  

Science Conference Proceedings (OSTI)

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.

J. Conca

2000-12-20T23:59:59.000Z

175

Fold Catastrophe Model of Fracture Propagation of Hydraulic Fracturing  

Science Conference Proceedings (OSTI)

According to energy conservation from the destruction of rock catastrophe, a new calculation method of the length of fracture propagation in hydraulic fracturing is proposed, and assuming the crack extends to approximate ellipse, the width calculation ... Keywords: hydraulic fracture, fold catastrophe, fracture parameters

Zhaowan Chun; Wan Tingting; Ai Chi; Ju Guoshuai

2010-05-01T23:59:59.000Z

176

EPRI Fault Current Management Guidebook, Fifth Edition  

Science Conference Proceedings (OSTI)

This document is an update of EPRI report 1020029, Fault Current Management Guidebook, Fourth Edition, on fault current effects and management in transmission and distribution systems. This guide is intended to be a snapshot of available references, information, and literature on the effects of high fault current on a number of power system components and various available and emerging fault-current-limiting technologies.

2011-12-19T23:59:59.000Z

177

Memory Fault Modeling Trends: A Case Study  

Science Conference Proceedings (OSTI)

In recent years, embedded memories are the fastest growing segment of system on chip. They therefore have a major impact on the overall Defect per Million (DPM). Further, the shrinking technologies and processes introduce new defects that cause previously ... Keywords: data backgrounds, dynamic faults, fault coverage, fault models, memory tests, static faults

Said Hamdioui; Rob Wadsworth; John Delos Reyes; Ad J. Van De Goor

2004-06-01T23:59:59.000Z

178

Fault Tree Analysis - A Bibliography  

Science Conference Proceedings (OSTI)

Fault tree analysis is a top-down approach to the identification of process hazards. It is touted as one of the best methods for systematically identifying and graphically displaying the many ways something can go wrong. This bibliography references ...

Program NASA Scientific and Technical Information

2000-07-01T23:59:59.000Z

179

SWIFT: Software Implemented Fault Tolerance  

Science Conference Proceedings (OSTI)

To improve performance and reduce power, processor designers employ advances that shrink feature sizes, lower voltage levels, reduce noise margins, and increase clock rates. However, these advances make processors more susceptible to transient faults ...

George A. Reis; Jonathan Chang; Neil Vachharajani; Ram Rangan; David I. August

2005-03-01T23:59:59.000Z

180

Subsurface fracture mapping from geothermal wellbores. Final report  

DOE Green Energy (OSTI)

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.

Hartenbaum, B.A.; Rawson, G.

1983-08-01T23:59:59.000Z

Note: This page contains sample records for the topic "fracture zones faults" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


181

Passive fault current limiting device  

DOE Patents (OSTI)

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.

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

1999-04-06T23:59:59.000Z

182

Measuring and Modeling Flow in Welded Fractured Tuffs  

SciTech Connect

We have carried out a series of in situ liquid-release experiments in conjunction with a numerical modeling study to examine the effect of the rock matrix on liquid flow and transport occurring primarily through the fracture network. Field experiments were conducted in the highly fractured Topopah Spring welded tuff at a site accessed from the Exploratory Studies Facility (ESFS), an underground laboratory in the unsaturated zone at Yucca Mountain, Nevada. During the experiment, wetting-front movement, flow-field evolution, and drainage of fracture flow paths were evaluated. Modeling was used to aid in experimental design, predict experimental results, and study the physical processes accompanying liquid flow through unsaturated fractured welded tuff. Field experiments and modeling suggest that it may not be sufficient to conceptualize the fractured tuff as consisting of a single network of high-permeability fractures embedded in a low-permeability matrix. The need to include a secondary fracture network is demonstrated by comparison to the liquid flow observed in the field.

R. Salve; C. Doughty; J.S. Wang

2001-10-03T23:59:59.000Z

183

Fracturing fluids -- then and now  

Science Conference Proceedings (OSTI)

Fracturing fluid provides the means by which the hydraulic fracturing process can take place. All applications of well stimulation by fracturing must include selection of fracturing fluid in the initial phases of fracture design and treatment planning. Fracturing fluid has two important purposes: (1) to provide sufficient viscosity to suspend and transport proppant deep into the created fracture system and (2) to decompose, or break, chemically to a low viscosity to allow flowback of a major part of the fluid to the surface for fracture cleanup after the treatment is completed. Because of the importance of its rheological properties and behavior in the fracture under reservoir conditions during (and immediately after) the treatment, service company research laboratories have spent millions of dollars on R and D of fracturing fluids.

Jennings, A.R. Jr. [Enhanced Well Stimulation Inc., Plano, TX (United States)

1996-07-01T23:59:59.000Z

184

Suspensions in hydraulic fracturing  

Science Conference Proceedings (OSTI)

Suspensions or slurries are widely used in well stimulation and hydraulic fracturing processes to enhance the production of oil and gas from the underground hydrocarbon-bearing formation. The success of these processes depends significantly upon having a thorough understanding of the behavior of suspensions used. Therefore, the characterization of suspensions under realistic conditions, for their rheological and hydraulic properties, is very important. This chapter deals with the state-of-the-art hydraulic fracturing suspension technology. Specifically it deals with various types of suspensions used in well stimulation and fracturing processes, their rheological characterization and hydraulic properties, behavior of suspensions in horizontal wells, review of proppant settling velocity and proppant transport in the fracture, and presently available measurement techniques for suspensions and their merits. Future industry needs for better understanding of the complex behavior of suspensions are also addressed. 74 refs., 21 figs., 1 tab.

Shah, S.N. [Univ. of Oklahoma, Norman, OK (United States)

1996-12-31T23:59:59.000Z

185

Relative permeability through fractures  

DOE Green Energy (OSTI)

The mechanism of two-phase flow through fractures is of importance in understanding many geologic processes. Currently, two-phase flow through fractures is still poorly understood. In this study, nitrogen-water experiments were done on both smooth and rough parallel plates to determine the governing flow mechanism for fractures and the appropriate methodology for data analysis. The experiments were done using a glass plate to allow visualization of flow. Digital video recording allowed instantaneous measurement of pressure, flow rate and saturation. Saturation was computed using image analysis techniques. The experiments showed that gas and liquid phases flow through fractures in nonuniform separate channels. The localized channels change with time as each phase path undergoes continues breaking and reforming due to invasion of the other phase. The stability of the phase paths is dependent on liquid and gas flow rate ratio. This mechanism holds true for over a range of saturation for both smooth and rough fractures. In imbibition for rough-walled fractures, another mechanism similar to wave-like flow in pipes was also observed. The data from the experiments were analyzed using Darcy's law and using the concept of friction factor and equivalent Reynold's number for two-phase flow. For both smooth- and rough-walled fractures a clear relationship between relative permeability and saturation was seen. The calculated relative permeability curves follow Corey-type behavior and can be modeled using Honarpour expressions. The sum of the relative permeabilities is not equal one, indicating phase interference. The equivalent homogeneous single-phase approach did not give satisfactory representation of flow through fractures. The graphs of experimentally derived friction factor with the modified Reynolds number do not reveal a distinctive linear relationship.

Diomampo, Gracel, P.

2001-08-01T23:59:59.000Z

186

FRACTURING FLUID CHARACTERIZATION FACILITY  

SciTech Connect

Hydraulic fracturing technology has been successfully applied for well stimulation of low and high permeability reservoirs for numerous years. Treatment optimization and improved economics have always been the key to the success and it is more so when the reservoirs under consideration are marginal. Fluids are widely used for the stimulation of wells. The Fracturing Fluid Characterization Facility (FFCF) has been established to provide the accurate prediction of the behavior of complex fracturing fluids under downhole conditions. The primary focus of the facility is to provide valuable insight into the various mechanisms that govern the flow of fracturing fluids and slurries through hydraulically created fractures. During the time between September 30, 1992, and March 31, 2000, the research efforts were devoted to the areas of fluid rheology, proppant transport, proppant flowback, dynamic fluid loss, perforation pressure losses, and frictional pressure losses. In this regard, a unique above-the-ground fracture simulator was designed and constructed at the FFCF, labeled ''The High Pressure Simulator'' (HPS). The FFCF is now available to industry for characterizing and understanding the behavior of complex fluid systems. To better reflect and encompass the broad spectrum of the petroleum industry, the FFCF now operates under a new name of ''The Well Construction Technology Center'' (WCTC). This report documents the summary of the activities performed during 1992-2000 at the FFCF.

Subhash Shah

2000-08-01T23:59:59.000Z

187

Tectonic Setting and Characteristics of Natural Fractures in Mesaverde and Dakota Reservoirs of the San Juan Basin, New Mexico and Colorado  

SciTech Connect

A set of vertical extension fractures, striking N-S to NNE-SSW but with local variations, is present in both the outcrop and subsurface in both Mesaverde and Dakota sandstones. Additional sets of conjugate shear fractures have been recognized in outcrops of Dakota strata and may be present in the subsurface. However, the deformation bands prevalent locally in outcrops in parts of the basin as yet have no documented subsurface equivalent. The immature Mesaverde sandstones typically contain relatively long, irregular extension fractures, whereas the quartzitic Dakota sandstones contain short, sub-parallel, closely spaced, extension fractures, and locally conjugate shear planes as well. Outcrops typically display secondary cross fractures which are rare in the subsurface, although oblique fractures associated with local structures such as the Hogback monocline may be present in similar subsurface structures. Spacings of the bed-normal extension fractures are approximately equal to or less than the thicknesses of the beds in which they formed, in both outcrop and subsurface. Fracture intensities increase in association with faults, where there is a gradation from intense fracturing into fault breccia. Bioturbation and minimal cementation locally inhibited fracture development in both formations, and the vertical limits of fracture growth are typically at bedding/lithology contrasts. Fracture mineralizations have been largely dissolved or replaced in outcrops, but local examples of preserved mineralization show that the quartz and calcite common to subsurface fractures were originally present in outcrop fractures. North-south trending compressive stresses created by southward indentation of the San Juan dome area (where Precambrian rocks are exposed at an elevation of 14,000 ft) and northward indentation of the Zuni uplift, controlled Laramide-age fracturing. Contemporaneous right-lateral transpressive wrench motion due to northeastward translation of the basin was both concentrated at the basin margins (Nacimiento uplift and Hogback monocline on east and west edges respectively) and distributed across the strata depth.

LORENZ, JOHN C.; COOPER, SCOTT P.

2001-01-01T23:59:59.000Z

188

Automatic fault extraction and simulation of layout realistic faults for integrated analogue circuits  

Science Conference Proceedings (OSTI)

A comprehensive tool has been implemented for the comparison of different test preparation techniques and target faults. It comprises of the realistic fault characterisation program LIFT that can extract sets of various faults from a given analogue or ... Keywords: AnaFAUL, LIFT, VCO, analogue integrated circuits, automatic analogue fault simulation program, catastrophic faults, circuit analysis computing, circuit layout, fault diagnosis, integrated analogue circuits, integrated circuit layout, integrated circuit testing, mixed analogue-digital integrated circuits, mixed-signal circuit, parametric faults, realistic fault characterisation program, simulation, test preparation, voltage-controlled oscillators

C. Sebeke; J. P. Teixeira; M. J. Ohletz

1995-03-01T23:59:59.000Z

189

Fault detection of fault ride through for doubly-fed induction generator based wind energy systems.  

E-Print Network (OSTI)

??Fault detection and mitigation is of high importance for existing DFIG based wind energy conversion systems. Keeping the doubly-fed induction generator (DFIG) online during faults… (more)

Ramroop, Shoba AD

2008-01-01T23:59:59.000Z

190

Self-potential observations during hydraulic fracturing  

E-Print Network (OSTI)

potential measurements during hydraulic fracturing of BunterSP response during hydraulic fracturing. Citation: Moore, J.observations during hydraulic fracturing, J. Geophys. Res. ,

Moore, J R; Glaser, Steven D

2007-01-01T23:59:59.000Z

191

Self-potential observations during hydraulic fracturing  

E-Print Network (OSTI)

and T. W. Keech (1977), Hydraulic fracture mapping usingpotential measurements during hydraulic fracturing of BunterSP Monitoring during hydraulic fracturing using the TG-2

Moore, Jeffrey R.; Glaser, Steven D.

2008-01-01T23:59:59.000Z

192

Hydraulic Fracturing Poster | Department of Energy  

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

Hydraulic Fracturing Poster Hydraulic Fracturing Poster Educational poster graphically displaying the key components of hydraulic fracturing. Teachers: If you would like hard...

193

Enterprise Zone Program (Illinois)  

Energy.gov (U.S. Department of Energy (DOE))

The Enterprise Zone Program provides eligible businesses that relocate or expand to a designated zone with tax incentives such as: 1) an investment tax credit; 2) a job tax credit for each job...

194

MODIFIED ZONE METHOD CALCULATOR  

NLE Websites -- All DOE Office Websites (Extended Search)

Zone Method is recommended for R-value calculations in steel stud walls by the 1997 ASHRAE Handbook of Fundamentals ASHRAE 1997. The Modified Zone Method is similar to the...

195

Reinvestment Zones (Texas)  

Energy.gov (U.S. Department of Energy (DOE))

Reinvestment Zones a local economic development tool used by municipalities and counties throughout the state of Texas. These zones can be created for the purpose of granting local businesses ad...

196

A Comprehensive Study Of Fracture Patterns And Densities In The Geysers  

Open Energy Info (EERE)

Study Of Fracture Patterns And Densities In The Geysers Study Of Fracture Patterns And Densities In The Geysers Geothermal Reservoir Using Microearthquake Shear-Wave Splitting Tomography Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Report: A Comprehensive Study Of Fracture Patterns And Densities In The Geysers Geothermal Reservoir Using Microearthquake Shear-Wave Splitting Tomography Details Activities (1) Areas (1) Regions (0) Abstract: In this project we developed a method for using seismic S-wave data to map the patterns and densities of sub-surface fractures in the NW Geysers Geothermal Field/ (1) This project adds to both the general methods needed to characterize the geothermal production fractures that supply steam for power generation and to the specific knowledge of these in the Geysers area. (2)By locating zones of high fracture density it will be

197

Experimental study of the transition from brittle shear fractures to joints  

E-Print Network (OSTI)

Current geologic thinking is that there are two, and only two, distinct types of brittle fractures, joints and shear fractures (faults). For over half a century, it has been debated that a third type of fracture, referred to as hybrid fractures, could exist and that joints and shear fractures may be end members of a continuous spectrum of brittle fractures. Hybrid fractures are hypothesized to form under mixed compressive and tensile stress states and have structural characteristics intermediate to those of joints and shear fractures. While this hypothesis is accepted in many modern structural geology textbooks used at the college and graduate level, no unchallenged evidence exists for the existence of hybrid fractures. Following the general methodology of a previously performed study by W.F. Brace (1964), but incorporating several key modifications to the experimental methods, a series of dog-bone triaxial experiments were performed on Carrara marble at room temperature, an axial extension rate of 2x10?² mm s?¹, and confining pressures between 7.5 and 170 MPa. The experiments provide strong evidence for the existence of hybrid fractures on the basis of the progressive change in fracture orientation, surface morphology, and failure strength between end-member joints and shear fractures. At the lowest confining pressures (7.5 to 60 MPa), fractures are oriented approximately parallel to the maximum principal stress, []?, form at an axial stress []?, of approximately -7.75 MPa (i.e. the uniaxial tensile strength), and display fracture surfaces characterized by many reflective cleavage faces, consistent with jointing. At the highest confining pressures (130 to 170 MPa), fractures are oriented from 13.4? to 21.6? to []?, form under completely compressive stress states with []? between 0 and 4.3 MPa, and are characterized by powdery white surfaces with short slip lineations, consistent with shear fracturing. At intermediate confining pressures (70 to 120 MPa), fractures are oriented from 3.7? to 12.4? to []?, form under mixed stress conditions with s3 ranging from -10.6 to -3.0 MPa, and display both reflective cleavage faces and powdery white surfaces with short slip lineations, consistent with hybrid fracturing.

Ramsey, Jonathan Michael

2003-01-01T23:59:59.000Z

198

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

Science Conference Proceedings (OSTI)

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 aquifer–3, lower clastic confining unit–1, and Mesozoic granite confining unit).

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

2011-02-01T23:59:59.000Z

199

Field Mapping At Walker-Lane Transitional Zone Region (Shevenell, Et Al.,  

Open Energy Info (EERE)

Walker-Lane Transitional Zone Region (Shevenell, Et Al., Walker-Lane Transitional Zone Region (Shevenell, Et Al., 2008) Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Exploration Activity: Field Mapping At Walker-Lane Transitional Zone Region (Shevenell, Et Al., 2008) Exploration Activity Details Location Walker-Lane Transition Zone Geothermal Region Exploration Technique Field Mapping Activity Date Usefulness could be useful with more improvements DOE-funding Unknown Notes On a more local scale, Faulds et al. (2003, 2005a, 2005b, 2006) have conducted structural analysis and detailed geologic mapping at a number of sites throughout Nevada and have found that productive geothermal systems typically occur in one of several structural settings, including step-overs in normal fault zones, near the ends of major normal faults where the

200

ASHRAE Climate Zones | Open Energy Information  

Open Energy Info (EERE)

ASHRAE Climate Zones Jump to: 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...

Note: This page contains sample records for the topic "fracture zones faults" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


201

Estimating fracture parameters from p-wave velocity profiles about a geothermal well  

DOE Green Energy (OSTI)

The feasibility of locating fracture zones and estimating their crack parameters was examined using an areal well shoot method centered on Utah State Geothermal Well 9-1, Beaver County, Utah. High-resolution travel time measurements were made between a borehole sensor and an array of shot stations distributed radially and azimuthally about the well. Directional velocity behavior in the vicinity of the well was investigated by comparing velocity logs derived from the travel time data. Three fracture zones were identified form the velocity data, corroborating fracture indicators seen in other geophysical logs conducted in Well 9-1. Crack densities and average crack aspect ratios for these fracture zones were estimated using a self-consistent velocity theory (O'Connell and Budiansy 1974). Probable trends of these fracture zones were established from a combination of the data from the more distant shot stations and the results of a gravity survey. The results of this study indicate that the areal well shoot is a potentially powerful tool for the reconnaisance of fracture-controlled fluid and gas reservoirs. Improvements in methodology and hardware could transform it into an operationally viable survey method.

Jenkinson, J.T.; Henyey, T.L.; Sammis, C.G.; Leary, P.C.; McRaney, J.K.

1981-12-01T23:59:59.000Z

202

Fault block kinematics at a releasing stepover of the Eastern California  

Open Energy Info (EERE)

block kinematics at a releasing stepover of the Eastern California block kinematics at a releasing stepover of the Eastern California shear zone: Partitioning of rotation style in and around the Coso geothermal area and nascent metamorphic core complex Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Journal Article: Fault block kinematics at a releasing stepover of the Eastern California shear zone: Partitioning of rotation style in and around the Coso geothermal area and nascent metamorphic core complex Details Activities (1) Areas (1) Regions (0) Abstract: Pliocene lavas and sediments of Wild Horse Mesa in the Coso Range, CA exhibit clockwise vertical-axis rotation of fault-bounded blocks. This indicates localization of one strand of the Eastern California shear zone/Walker Lane Belt within a large-scale, transtensional, dextral,

203

TEMPORAL VARIATIONS OF FRACTURE DIRECTIONS AND FRACTURE DENSITIES IN THE  

Open Energy Info (EERE)

TEMPORAL VARIATIONS OF FRACTURE DIRECTIONS AND FRACTURE DENSITIES IN THE TEMPORAL VARIATIONS OF FRACTURE DIRECTIONS AND FRACTURE DENSITIES IN THE COSO GEOTHERMAL FIELD FROM ANALYSES OF SHEAR-WAVE SPLITTING Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Conference Proceedings: TEMPORAL VARIATIONS OF FRACTURE DIRECTIONS AND FRACTURE DENSITIES IN THE COSO GEOTHERMAL FIELD FROM ANALYSES OF SHEAR-WAVE SPLITTING Details Activities (1) Areas (1) Regions (0) Abstract: This project aims to improve understanding of the subsurface fracture system in the Coso geothermal field, located in the east central California. We applied shear-wave splitting technique on a set of high quality, locally recorded microearthquake (MEQ) data. Four major fracture directions have been identified from the seismograms recorded by the permanent sixteen-station down-hole array: N10- 20W, NS, N20E, and N40-45E,

204

theoretical and applied fracture  

E-Print Network (OSTI)

example.A steam generator tubing severely affected by the stress corrosion cracking is studied during most of stress corrosion cracking in the tube expansion transition zone. 1. Introduction Steam generator (SG corrosion cracking (SCC)in the tube expansion transition zone seems presently to be the leading degradation

Cizelj, Leon

205

Definition: Fault Current Limiting | Open Energy Information  

Open Energy Info (EERE)

Limiting Limiting Jump to: navigation, search Dictionary.png Fault Current Limiting Fault current limiting can be achieved through sensors, communications, information processing, and actuators that allow the utility to use a higher degree of network coordination to reconfigure the system to prevent fault currents from exceeding damaging levels. Fault current limiting can also be achieved through the implementation of special stand alone devices known as Fault Current Limiters (FCLs) which act to automatically limit high through currents that occur during faults.[1] Related Terms fault, fault current limiter References ↑ SmartGrid.gov 'Description of Functions' Temp LikeLike UnlikeLike You like this.Sign Up to see what your friends like. late:ISGANAttributionsmart grid,smart grid,smart grid,smart grid,

206

Definition: Fault Current Limiter | Open Energy Information  

Open Energy Info (EERE)

Limiter Limiter Jump to: navigation, search Dictionary.png Fault Current Limiter A fault current limiter prevents current in an electrical circuit from exceeding a predetermined level by increasing the electrical impedance of that circuit before the current through the circuit exceeds that level. Fault current limiters are designed so as to minimize the impedance of the circuit under normal conditions to reduce losses, but increase the impedance of the circuit under fault conditions to limit fault current.[1] View on Wikipedia Wikipedia Definition A Fault Current Limiter (FCL) is a device which limits the prospective fault current when a fault occurs (e.g. in a power transmission network). The term includes superconducting devices and non-superconducting devices, however some of the more simple non-superconducting devices (such

207

Breakthrough in fracture mechanics  

SciTech Connect

Fracture mechanics, the science of calculating material characteristics, stress, and flaws in plant equipment to evaluate structural integrity, usually spares the owners of nuclear power plants unnecessary expense. Instead of replacing equipment prematurely or waiting for costly, unscheduled materials failures that can take months to repair and cost thousands of dollars a day for replacement power, utilities use fracture mechanics techniques to carefully consider their options. If analyses show repair is unnecessary, plant operation can confidently be resumed. If repair is required, it can either be done immediately or, if deferrable, be scheduled for a later, more convenient outage.

Lihach, N.

1981-05-01T23:59:59.000Z

208

Fracture characterization of multilayered reservoirs  

Science Conference Proceedings (OSTI)

Fracture treatment optimization techniques have been developed using Long-Spaced-Digital-Sonic (LSDS) log, pumpin-flowback, mini-frac, and downhole treating pressure data. These analysis techniques have been successfully applied in massive hydraulic fracturing (MHF) of ''tight gas'' wells. Massive hydraulic fracture stimulations have been used to make many tight gas reservoirs commercially attractive. However, studies have shown that short highly conductive fractures are optimum for the successful stimulation of wells in moderate permeability reservoirs. As a result, the ability to design and place optimal fractures in these reservoirs is critical. This paper illustrates the application of fracture analysis techniques to a moderate permeability multi-layered reservoir. These techniques were used to identify large zonal variations in rock properties and pore pressure which result from the complex geology. The inclusion of geologic factors in fracture treatment design allowed the placement of short highly conductive fractures which were used to improve injectivity and vertical sweep, and therefore, ultimate recovery.

Britt, L.K.; Larsen, M.J.

1986-01-01T23:59:59.000Z

209

Modeling interfacial fracture in Sierra.  

SciTech Connect

This report summarizes computational efforts to model interfacial fracture using cohesive zone models in the SIERRA/SolidMechanics (SIERRA/SM) finite element code. Cohesive surface elements were used to model crack initiation and propagation along predefined paths. Mesh convergence was observed with SIERRA/SM for numerous geometries. As the funding for this project came from the Advanced Simulation and Computing Verification and Validation (ASC V&V) focus area, considerable effort was spent performing verification and validation. Code verification was performed to compare code predictions to analytical solutions for simple three-element simulations as well as a higher-fidelity simulation of a double-cantilever beam. Parameter identification was conducted with Dakota using experimental results on asymmetric double-cantilever beam (ADCB) and end-notched-flexure (ENF) experiments conducted under Campaign-6 funding. Discretization convergence studies were also performed with respect to mesh size and time step and an optimization study was completed for mode II delamination using the ENF geometry. Throughout this verification process, numerous SIERRA/SM bugs were found and reported, all of which have been fixed, leading to over a 10-fold increase in convergence rates. Finally, mixed-mode flexure experiments were performed for validation. One of the unexplained issues encountered was material property variability for ostensibly the same composite material. Since the variability is not fully understood, it is difficult to accurately assess uncertainty when performing predictions.

Brown, Arthur A.; Ohashi, Yuki; Lu, Wei-Yang; Nelson, Stacy A. C.; Foulk, James W.,; Reedy, Earl David,; Austin, Kevin N.; Margolis, Stephen B.

2013-09-01T23:59:59.000Z

210

Fault diagnosis and fault tolerant control using set-membership approaches: Application to real case studies  

Science Conference Proceedings (OSTI)

This paper reviews the use of set-membership methods in fault diagnosis (FD) and fault tolerant control (FTC). Setmembership methods use a deterministic unknown-but-bounded description of noise and parametric uncertainty (interval ... Keywords: Fault Detection, Fault-Tolerant Control, Interval Models, Robustness, Set-Membership

Vicenç Puig

2010-12-01T23:59:59.000Z

211

Distribution Fault Location and Waveform Characterization  

Science Conference Proceedings (OSTI)

Automated fault location algorithms for distribution systems require monitoring equipment to record voltage and current waveforms during an event. In addition, most of these algorithms require circuit-impedance parameters to evaluate the fault location. Locating incipient faults and fault waveform characterization is the main aim of this project. This project builds on work done in 2008 towards sub-cycle blip identification using an algorithm based on arc voltage.

2009-12-11T23:59:59.000Z

212

Benchmarking of Fault-Location Technologies  

Science Conference Proceedings (OSTI)

This report resumes the studies on fault-location technologies that were conducted in 2009. These studies were undertaken in a joint project done with the collaboration of Hydro-Qubec, Long Island Power Authority, and the Electric Power Research Institute (EPRI). Two fault-location technologies were tested, the Reactance to Fault (RTF) implemented in the PQView application and the Voltage Drop Fault Location (VDFL) implemented in the MILE application. The RTF is based on substation voltage and current me...

2011-03-31T23:59:59.000Z

213

Investigation of Created Fracture Geometry through Hydraulic Fracture Treatment Analysis  

E-Print Network (OSTI)

Successful development of shale gas reservoirs is highly dependent on hydraulic fracture treatments. Many questions remain in regards to the geometry of the created fractures. Production data analysis from some shale gas wells quantifies a much smaller stimulated pore volume than what would be expected from microseismic evidence and reports of fracturing fluids reaching distant wells. In addition, claims that hydraulic fracturing may open or reopen a network of natural fractures is of particular interest. This study examines hydraulic fracturing of shale gas formations with specific interest in fracture geometry. Several field cases are analyzed using microseismic analysis as well as net pressure analysis of the fracture treatment. Fracture half lengths implied by microseismic events for some of the stages are several thousand feet in length. The resulting dimensions from microseismic analysis are used for calibration of the treatment model. The fracture profile showing created and propped fracture geometry illustrates that it is not possible to reach the full fracture geometry implied by microseismic given the finite amount of fluid and proppant that was pumped. The model does show however that the created geometry appears to be much larger than half the well spacing. From a productivity standpoint, the fracture will not drain a volume more than that contained in half of the well spacing. This suggests that for the case of closely spaced wells, the treatment size should be reduced to a maximum of half the well spacing. This study will provide a framework for understanding hydraulic fracture treatments in shale formations. In addition, the results from this study can be used to optimize hydraulic fracture treatment design. Excessively large treatments may represent a less than optimal approach for developing these resources.

Ahmed, Ibraheem 1987-

2012-12-01T23:59:59.000Z

214

High temperature superconducting fault current limiter  

DOE Patents (OSTI)

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.

Hull, J.R.

1997-02-04T23:59:59.000Z

215

Autonomic fault mitigation in embedded systems  

Science Conference Proceedings (OSTI)

Autonomy, particularly from a maintenance and fault-management perspective, is an increasingly desirable feature in embedded (and non-embedded) computer systems. The driving factors are several-including increasing pervasiveness of computer systems, ... Keywords: Autonomic computing, Embedded systems, Fault mitigation, Fault tolerance, Hierarchical concurrent finite-state machines, Model-based design

Sandeep Neema; Ted Bapty; Shweta Shetty; Steven Nordstrom

2004-10-01T23:59:59.000Z

216

Fault detection and diagnosis of technical systems  

Science Conference Proceedings (OSTI)

Sensors, actuators and/or physical components in technical systems are often affected by unpermitted or un-expected deviations from normal operation behaviour. The fault diagnosis task consists of determination of the fault type with as many details ... Keywords: fault detection and diagnosis, residuals, symptoms, technical systems

Ioana Fagarasan; S. ST. Iliescu

2008-06-01T23:59:59.000Z

217

CRT RSA algorithm protected against fault attacks  

Science Conference Proceedings (OSTI)

Embedded devices performing RSA signatures are subject to Fault Attacks, particularly when the Chinese Remainder Theorem is used. In most cases, the modular exponentiation and the Garner recombination algorithms are targeted. To thwart Fault Attacks, ... Keywords: RSA, chinese remainder theorem, fault attacks, modular exponentiation, simple power analysis, smart card

Arnaud Boscher; Robert Naciri; Emmanuel Prouff

2007-05-01T23:59:59.000Z

218

Designing Fault-Tolerant Mobile Systems  

Science Conference Proceedings (OSTI)

The purpose of this paper is to investigate how several innovative techniques, not all initially intended for fault-tolerance, can be applied in providing fault tolerance of complex mobile agent systems. Due to their roaming nature, mobile agents usually ... Keywords: exception handling, fault tolerance, mobile agents, software engineering, system structuring

Giovanna Di Marzo Serugendo; Alexander B. Romanovsky

2002-11-01T23:59:59.000Z

219

Rigid Body Simulation with Local Fracturing Effects  

Science Conference Proceedings (OSTI)

Focusing on the real-time and interactive ability features in the Virtual Reality application, we propose a fracture pattern based on local fracture mechanism. Taking advantage of the experience analysis or the offline computation verified fracture characteristic, ... Keywords: Rigid Body, pre-fracture, fracture pattern, local fracture, dynamics

Wu Bo; Zeng Liang; Wu Yagang

2011-05-01T23:59:59.000Z

220

High-resolution stratigraphic and structural characterization of the fault-partitioned Hickory Sandstone aquifer system, Mason County, central Texas  

E-Print Network (OSTI)

The Hickory Sandstone is an important aquifer in central Texas and is partitioned by faults that impede cross-fault fluid flow. This study provides a detailed stratigraphic and structural model in the vicinity of a normal, oblique-slip fault with 60' (18.3 m) of stratigraphic throw. The model is developed using 3500' (1050 m) of continuous core and geophysical logs from eleven closely spaced boreholes. The local stratigraphy is studied in detail and environments of deposition inferred. A model of fault evolution is inferred using the observed fault structure and throw distributions. Locally, the Hickory Sandstone consists of 450' (137 m) of Cambrian-aged, quartzose and arkosic sandstone with localized mudstone and siltstone interbeds and overlies Precambrian Town Mountain Granite. Within the study area, the Hickory Sandstone is subdivided into four facies: the cross-bedded facies, the mudstone facies, the interbedded sandstone facies and the hematite facies. These facies form a stacked sequence representing an initial braided-stream fluvial environment that grades into a high energy, open marine environment that closely matches the tide-dominated, high microtidal estuarine model of Reinson (1992). Lateral correlation of strata packages in the cross-bedded facies was very difficult and complicated development of the fault model. The study fault is a linked fault system consisting of several major segments. Two segments overlap and locally hard link along both strike and dip. The major fault segments also consist of several linked subsegments. Net stratigraphic throw decreases slightly upward from a maximum of 60' (18.3 m) near the granite basement. Where the major segments overlap, the throw exhibits systematic variations consistent with displacement transfer between the neighboring segments. The linked fault system is inferred to have formed by interaction and linkage of two, early, en echelon basement faults. Ultimately these faults propagated upward and laterally into the overlying Hickory Sandstone, interacted and partially hard-linked, producing a large linkage structure that affected subsequent, neighboring hanging wall deformation. Subsidiary small faults are common but do not exhibit simple spatial relations with the large fault segments. There is only a weak correlation between a fault's shear zone thickness and stratigraphic throw for faults with 1' to 60' (0.3 to 18.3 m) of throw.

Wilson, Jason Steven

2001-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "fracture zones faults" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


221

Sand control method employing special hydraulic fracturing technique  

SciTech Connect

A novel sand control method is disclosed wherein high viscosity, high sand concentration, fracturing fluids are pumped through sets of vertically oriented perforations in borehole casings located in unconsolidated or loosely consolidated pay zones. Various techniques are utilized to insure that sand fills disposed on either side of the borehole casing cover and substantially overlap each borehole casing perforation set. Procedures are then followed to bring the well into production without washing out the sand fills in these areas, whereby the resulting perforation-sand fill configurations effectively control sand production from the treated zone.

Medlin, W.L.; Mullins, L.D.; Zumwalt, G.L.

1983-04-05T23:59:59.000Z

222

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

DOE Green Energy (OSTI)

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.

Faybishenko, B. (ed.)

1999-02-01T23:59:59.000Z

223

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

SciTech Connect

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.

Faybishenko, B. (ed.)

1999-02-01T23:59:59.000Z

224

Geothermal: Educational Zone  

NLE Websites -- All DOE Office Websites (Extended Search)

GEOTHERMAL TECHNOLOGIES LEGACY COLLECTION - Educational Zone Geothermal Technologies Legacy Collection HelpFAQ | Site Map | Contact Us | Admin Log On HomeBasic Search About...

225

Renaissance Zones (North Dakota)  

Energy.gov (U.S. Department of Energy (DOE))

Renaissance Zones allow qualifying businesses and individuals to claim one or more tax incentives for purchasing, leasing, or making improvements to real property located in a North Dakota...

226

Isotopic evidence for the infiltration of mantle and metamorphic CO2-H2O fluids from below in faulted rocks from the San Andreas Fault System  

SciTech Connect

To characterize the origin of the fluids involved in the San Andreas Fault (SAF) system, we carried out an isotope study of exhumed faulted rocks from deformation zones, vein fillings and their hosts and the fluid inclusions associated with these materials. Samples were collected from segments along the SAF system selected to provide a depth profile from upper to lower crust. In all, 75 samples from various structures and lithologies from 13 localities were analyzed for noble gas, carbon, and oxygen isotope compositions. Fluid inclusions exhibit helium isotope ratios ({sup 3}He/{sup 4}He) of 0.1-2.5 times the ratio in air, indicating that past fluids percolating through the SAF system contained mantle helium contributions of at least 35%, similar to what has been measured in present-day ground waters associated with the fault (Kennedy et al., 1997). Calcite is the predominant vein mineral and is a common accessory mineral in deformation zones. A systematic variation of C- and O-isotope compositions of carbonates from veins, deformation zones and their hosts suggests percolation by external fluids of similar compositions and origin with the amount of fluid infiltration increasing from host rocks to vein to deformation zones. The isotopic trend observed for carbonates in veins and deformation zones follows that shown by carbonates in host limestones, marbles, and other host rocks, increasing with increasing contribution of deep metamorphic crustal volatiles. At each crustal level, the composition of the infiltrating fluids is thus buffered by deeper metamorphic sources. A negative correlation between calcite {delta}{sup 13}C and fluid inclusion {sup 3}He/{sup 4}He is consistent with a mantle origin for a fraction of the infiltrating CO{sub 2}. Noble gas and stable isotope systematics show consistent evidence for the involvement of mantle-derived fluids combined with infiltration of deep metamorphic H{sub 2}O and CO{sub 2} in faulting, supporting the involvement of deep fluids percolating through and perhaps weakening the fault zone. There is no clear evidence for a significant contribution from meteoric water, except for overprinting related to late weathering.

Pili, E.; Kennedy, B.M.; Conrad, M.E.; Gratier, J.-P.

2010-12-15T23:59:59.000Z

227

Vertical movement along the Cerro Prieto transform fault, Baja California, Mexico - a mechanism for geothermal energy renewal  

DOE Green Energy (OSTI)

Data from 53 geothermal wells to depths of 1 to 3 km on either side of the right-lateral Cerro Prieto fault, as well as geophysical data, indicate vertical displacements of this fault of 400 to 600 m. This episoidic vertical movement has offset deltaic sandstone reservoirs that are primarily at 1200 m and 1800 m depth and contain 250{sup 0} to 345{sup 0}C water. A major fracture system for convective fluid movement has been thus maintained, with production at 150 MW.

Vonder Haar, S.; Noble, J.E.; Puente Cruz, I.

1979-03-01T23:59:59.000Z

228

A Physically Based Approach for Modeling Multiphase Fracture-Matrix Interaction in Fractured Porous Media  

E-Print Network (OSTI)

in modeling multiphase flow in porous and fractured media,multiphase tracer transport in heterogeneous fractured porousof multiphase flow through fractured or porous media.

Wu, Yu-Shu; Pan, Lehua; Pruess, Karsten

2004-01-01T23:59:59.000Z

229

A physically based numerical approach for modeling fracture-matrix interaction in fractured reservoirs  

E-Print Network (OSTI)

in modeling multiphase flow in porous and fractured media,multiphase tracer transport in heterogeneous fractured porousof multiphase flow through fractured or porous media. 3.

Wu, Yu-Shu; Pruess, Karsten

2004-01-01T23:59:59.000Z

230

Barriers to faulting in the Basin-Range province: evidence from the Sou Hills transverse block  

Science Conference Proceedings (OSTI)

Transverse structural blocks may inhibit the propagation of fault ruptures in the Basin-Range province. The Sou Hills, between Dixie and Pleasant Valleys, is a block of uplifted Tertiary bedrock transverse to the NNE-SSW trend of the central Nevada seismic belt. Three lines of evidence indicate that offset due to normal faulting is much less in the Sou Hills compared to adjacent segments of the seismic belt. First, estimates of total late Cenozoic offsets of pre-extension basalts show that the total offset is less in the Sou Hills. Second, analyses of landforms that reflect rates of relative uplift show that Quaternary tectonic activity on range-bounding faults declines where faults join the Sou Hills. Third, measurements of late Quaternary fault scarps show that individual rupture segments in the Sou Hills are shorter in length and have smaller displacements compared to the nearly continuous ruptures of several meters offset found along the Tobin and Stillwater Ranges to the north and south. The Sou Hills rupture pattern is distinctive: ruptures are dispersed over a wide zone rather than being concentrated along well-defined range fronts. Normal faulting patterns produced by the 1915 Pleasant Valley, Nevada and the 1983 Borah Peak, Idaho earthquakes indicate that a discontinuous, spatially dispersed faulting style typifies ruptures which die out in transverse bedrock features. These historic analogues support a model for prehistoric faulting in which ruptures have repeatedly died out in the Sou Hills. Transverse blocks such as the Sou Hills appear to present barriers to propagating ruptures.

Fonseca, J.E.

1985-01-01T23:59:59.000Z

231

Correlating laboratory observations of fracture mechanical properties to hydraulically-induced microseismicity in geothermal reservoirs.  

Science Conference Proceedings (OSTI)

To date, microseismicity has provided an invaluable tool for delineating the fracture network produced by hydraulic stimulation of geothermal reservoirs. While the locations of microseismic events are of fundamental importance, there is a wealth of information that can be gleaned from the induced seismicity (e.g. fault plane solutions, seismic moment tensors, source characteristics). Closer scrutiny of the spatial and temporal evolution of seismic moment tensors can shed light on systematic characteristics of fractures in the geothermal reservoir. When related to observations from laboratory experiments, these systematic trends can be interpreted in terms of mechanical processes that most likely operate in the fracture network. This paper reports on mechanical properties that can be inferred from observations of microseismicity in geothermal systems. These properties lead to interpretations about fracture initiation, seismicity induced after hydraulic shut-in, spatial evolution of linked fractures, and temporal evolution of fracture strength. The correlations highlight the fact that a combination of temperature, stressing rate, time, and fluid-rock interactions can alter the mechanical and fluid transport properties of fractures in geothermal systems.

Stephen L. Karner, Ph.D

2006-02-01T23:59:59.000Z

232

Fault-ignorant Quantum Search  

E-Print Network (OSTI)

We investigate the problem of quantum searching on a noisy quantum computer. Taking a 'fault-ignorant' approach, we analyze quantum algorithms that solve the task for various different noise strengths, which are possibly unknown beforehand. We prove lower bounds on the runtime of such algorithms and thereby find that the quadratic speedup is necessarily lost (in our noise models). However, for low but constant noise levels the algorithms we provide (based on Grover's algorithm) still outperform the best noiseless classical search algorithm.

Peter Vrana; David Reeb; Daniel Reitzner; Michael M. Wolf

2013-07-02T23:59:59.000Z

233

Limitations for detecting small-scale faults using the coherency analysis of seismic data  

E-Print Network (OSTI)

Coherency analyzes the trace to trace amplitude similarities recorded by seismic waves. Coherency algorithms have been used to identify the structural or stratigraphic features of an area but the limitations for detecting small-scale features are not known. These limitations become extremely important when interpreting coherency within poorly acquired or processed data sets. In order to obtain a better understanding of the coherency limitations, various synthetic seismic data sets were created. The sensitivity of the coherency algorithms to variations in wave frequency, signal-to-noise ratio and fault throw was investigated. Correlation between the coherency values of a faulted reflector and the known offset shows that coherency has the ability to detect the presence of various scale features that may be previously thought to be below seismic resolution or difficult to discriminate with conventional interpretation methods. Coherency values had a smaller standard deviation and were less sensitive to noise when processed with a temporal window length less than one period. A fault could be detected by coherency when the signal-to-noise ratio was >3. A fault could also be detected as long as the throw-to-wavelength ratio was >5% or two-way traveltime-toperiod >10%. Therefore, this study suggests that coherency has the ability to detect a fault as long as the frequency of the data imaging that fault has a period no greater than one order of magnitude to the traveltime through the fault and that the signal can easily be distinguished from noise. Results from application of the coherency analysis were applied to the characterization of a very deep fault and fracture system imaged by a field seismic data set. A series of reverse and strike-slip faults were detected and mapped. Magnitudes of the throws for these faults were not known, but subtle amplitude anomalies in seismic sections confirmed the coherency analysis. The results of this study suggest that coherency has demonstrated an ability to detect features that would normally beoverlooked using traditional interpretation methods and has many future implications for poorly imaged seismic areas, such as sub-salt.

Barnett, David Benjamin

2003-05-01T23:59:59.000Z

234

CONTROL AND FAULT DETECTOR CIRCUIT  

DOE Patents (OSTI)

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.

Winningstad, C.N.

1958-04-01T23:59:59.000Z

235

Determination of the effect of formation water on fracture-fluid cleanup  

SciTech Connect

Understanding hydraulic-fracture cleanup is essential for improving well stimulation. Residual gel damages fracture conductivity, shortens effective fracture half-length, and limits well productivity. The drive to develop fluids, additives, and procedures that minimize this damage continues to be a dominant theme in fracture-fluid-development programs. Fracture cleanup is a complex problem, and many parameters (e.g., fluid system, job design, flowback procedure, and reservoir conditions) can influence polymer and fluid recovery efficiencies. Often, specific products and methods that work well in one reservoir have little effect in another. Systematic analysis of fluid and polymer returns after a treatment is completed is the only way to quantify fracture cleanup. This is referred to as flowback analysis. This paper discusses a flowback-analysis field study on large hydraulic-fracturing treatments in the Taylor zone of the Cotton Valley formation in east Texas. This is a low-permeability (approximately 0.01 md) tight gas formation. It is a heterogeneous zone with layers of productive sandstone interspersed with relatively impermeable layers of shale. A typical well in this field initially produces approximately 0.75 to 1.3 MMcf/D gas and 35 to 40 bbl of water/MMcf of gas. The returns from 10 wells in this field were analyzed thoroughly.

NONE

1998-03-01T23:59:59.000Z

236

Procedure for estimating fracture energy from fracture surface roughness  

DOE Patents (OSTI)

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.

Williford, Ralph E. (Kennewick, WA)

1989-01-01T23:59:59.000Z

237

Historic Surface Faulting and Paleoseismicity in the Area of the 1954  

Open Energy Info (EERE)

Historic Surface Faulting and Paleoseismicity in the Area of the 1954 Historic Surface Faulting and Paleoseismicity in the Area of the 1954 Rainbow Mountain-Stillwater Earthquake Sequence, Central Nevada Jump to: navigation, search OpenEI Reference LibraryAdd to library Journal Article: Historic Surface Faulting and Paleoseismicity in the Area of the 1954 Rainbow Mountain-Stillwater Earthquake Sequence, Central Nevada Abstract The Rainbow Mountain area was the site of three surface-rupturing earthquakes on 6 July and 23 August 1954. More than 50 field measurements of surface offsets constrain the distribution of slip along the discontinuous and distributed rupture zone that formed during the earthquake sequence. Vertical offsets reach a maximum of ~0.8 m with the average vertical offset being ~0.2 m. In contrast to original reports, we

238

Intersecting Fault Trends and Crustal-Scale Fluid Pathways Below the Dixie  

Open Energy Info (EERE)

Intersecting Fault Trends and Crustal-Scale Fluid Pathways Below the Dixie Intersecting Fault Trends and Crustal-Scale Fluid Pathways Below the Dixie Valley Geothermal Area, Nevada, Inferred from 3d Magnetotelluric Surveying Jump to: navigation, search OpenEI Reference LibraryAdd to library Conference Paper: Intersecting Fault Trends and Crustal-Scale Fluid Pathways Below the Dixie Valley Geothermal Area, Nevada, Inferred from 3d Magnetotelluric Surveying Abstract Geothermal systems may occur in zones of structural dilatency which create the crustal plumbing that al-lows concentration of high-temperature fluids from surrounding volumes. While structural orientations of the U.S. Great Basin are dominated visually by the NNE-oriented horst-graben morphology, other alignments are apparent, perhaps principally a NNW-trending grain

239

Uncertainty in the maximum principal stress estimated from hydraulic fracturing Measurements due to the presence of the induced fracture  

E-Print Network (OSTI)

Laboratory study of hydraulic fracturing pressure data?Howevaluation of hydraulic fracturing stress measurementreopening during hydraulic fracturing stress determinations.

Rutqvist, Jonny; Tsang, Chin-fu; Stephansson, Ove

2000-01-01T23:59:59.000Z

240

Identification of MHF (massive hydraulic fracturing) fracture planes and flow paths: A correlation of well log data with patterns in locations of induced seismicity  

DOE Green Energy (OSTI)

One of the critical steps in developing a hot dry rock geothermal system is the creation of flow paths through the rock between two wellbores. To date, circulation systems have only been created by drilling one wellbore, hydraulically fracturing the well (which induces microearthquakes), locating the microearthquakes and then drilling a second wellbore through the zone of seismicity. A technique for analyzing the pattern of seismicity to determine where fracture planes are located in the seismically active region has recently been developed. This allows us to distinguish portions of the seismically active volume which are most likely to contain significant flow paths. We applied this technique to seismic data collected during a massive hydraulic fracturing (MHF) treatment and found that the fracture planes determined by the seismic method are confirmed by borehole temperature and caliper logs which indicate where permeable fractures and/or zones of weakness intersect the wellbores. A geometric model based on these planes and well log data has enhanced our understanding of the reservoir flow paths created by fracturing and is consistent with results obtained during production testing of the reservoir.

Dreesen, D.; Malzahn, M.; Fehler, M.; Dash, Z.

1987-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "fracture zones faults" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


241

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

SciTech Connect

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.

Gary Mavko

2000-10-01T23:59:59.000Z

242

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

DOE Green Energy (OSTI)

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.

Regueiro, Richard A. (University of Colorado, Boulder, CO); Borja, R. I. (Stanford University, Stanford, CA); Foster, C. D. (Stanford University, Stanford, CA)

2006-10-01T23:59:59.000Z

243

Thermal depletion of a geothermal reservoir with both fracture and pore permeability  

DOE Green Energy (OSTI)

A method for estimating the useful lifetime of a reservoir in porous rock where the injection and production wells intersect a fracture system is presented. Equations were derived for the pore-fluid and fracture-fluid temperatures averaged over large regions of the geothermal field. Problems such as incomplete areal sweep and interfingering of cool and hot fluids are ignored. Approximate equations relating average temperatures to the heat flowing from rock to fluid were developed, and their use is justified by comparing the results with solutions of the exact equations. The equations for the temperature decline can be solved quickly. In the model, fractures are characterized by three parameters: aperture w, permeability k/sub fr/, and spacings between fractures D. For certain values of these parameters, cool reinjected fluid in fractures may reach the production wells long before all the warm pore fluid has been tapped, shortening the useful lifetime of the field. The traditional (and important) problems of reservoir engineering, flow rate determination, drawdown, sweep patterns, etc. were ignored. Thus the results are most useful in providing a correction factor which can be applied to lifetime estimates obtained from a detailed simulation of a field assuming porous rock. That correction factor is plotted for clean fractures (k/sub fr/ = w/sup 2//12) as a function of w and D for several lifetime ranges. Small-scale fractures seen in cores from the Salton Sea Geothermal Field are too closely spaced to reduce lifetime estimates. However, large-scale fault systems exist within that field, and they are attractive drilling targets because they produce large flow rates. If large scale faults communicate between injection and production wells, they may reduce the useful lifetime of those wells.

Kasameyer, P.W.; Schroeder, R.C.

1976-08-10T23:59:59.000Z

244

Faulting in the Yucca Mountain region: Critical review and analyses of tectonic data from the central Basin and Range  

SciTech Connect

Yucca Mountain, Nevada, has been proposed as the potential site for a high-level waste (HLW) repository. The tectonic setting of Yucca Mountain presents several potential hazards for a proposed repository, such as potential for earthquake seismicity, fault disruption, basaltic volcanism, magma channeling along pre-existing faults, and faults and fractures that may serve as barriers or conduits for groundwater flow. Characterization of geologic structures and tectonic processes will be necessary to assess compliance with regulatory requirements for the proposed high level waste repository. In this report, we specifically investigate fault slip, seismicity, contemporary stain, and fault-slip potential in the Yucca Mountain region with regard to Key Technical Uncertainties outlined in the License Application Review Plan (Sections 3.2.1.5 through 3.2.1.9 and 3.2.2.8). These investigations center on (i) alternative methods of determining the slip history of the Bare Mountain Fault, (ii) cluster analysis of historic earthquakes, (iii) crustal strain determinations from Global Positioning System measurements, and (iv) three-dimensional slip-tendency analysis. The goal of this work is to assess uncertainties associated with neotectonic data sets critical to the Nuclear Regulatory Commission and the Center for Nuclear Waste Regulatory Analyses` ability to provide prelicensing guidance and perform license application review with respect to the proposed HLW repository at Yucca Mountain.

Ferrill, D.A.; Stirewalt, G.L.; Henderson, D.B.; Stamatakos, J.; Morris, A.P.; Spivey, K.H. [Southwest Research Inst., San Antonio, TX (United States). Center for Nuclear Waste Regulatory Analyses; Wernicke, B.P. [California Inst. of Tech., Pasadena, CA (United States). Div. of Geological and Planetary Sciences

1996-03-01T23:59:59.000Z

245

Practical simulation of hierarchical brittle fracture  

Science Conference Proceedings (OSTI)

A novel practical method for brittle fracture simulation is presented. Our fracture model is represented by a tree structure, and all elementary fracture pieces are hierarchically connected. Each node in a fracture tree has a glue table to define connections ... Keywords: fluid, fracture, rigid body

Seungtaik Oh; Seunghyup Shin; Hyeryeong Jun

2012-05-01T23:59:59.000Z

246

Hardware Fault Insertion Techniques and Tools  

E-Print Network (OSTI)

The concept of dependability validation becomes more and more important regarding big public telecom systems. This is why fault insertion has been widely accepted as a means of testing the fault handling mechanisms of the systems. This master thesis classifies and compares fault insertion techniques used within the industry. It also looks into internal fault insertion techniques used by the people at Ericsson Telecom working with the AXD301 ATM switch. Hardware Fault Insertion Techniques and Tools 2 Acknowledgements The following people at Ericsson has contributed to this thesis in one way or another: Roger Nordmark Mattias Rimbark Bengt Kvist Anders strm Kenny Ohlsson Johan Jeppson Johan Eklv Also a thank you to my supervisor at KTH: Axel Jantsch A special thanks also to my good friend and colleague: Robert Thorhuus Hardware Fault Insertion Techniques and Tools 3 Abbreviations ASIC - Application Specific Integrated Circuit ATM - Asynchronous Transfer Mode BSDL - Boundary Scan De...

Emil Savqvist; Roger Nordmark; Mattias Rimbark; Bengt Kvist; Anders Åström; Kenny Ohlsson; Johan Eklöv; Axel Jantsch; Robert Thorhuus; Hw Hard Ware

2000-01-01T23:59:59.000Z

247

Fault Current Management Guidebook--Updated  

Science Conference Proceedings (OSTI)

Due to increased load demands and reduced incentives to build new transmission, energy companies are increasing power flows on existing transmission assets, which will increase fault current levels throughout the power system. Also, new generation sources to be added at the transmission and distribution network will increase power flows and, consequently, fault current levels. Under increased power flow conditions on existing assets, managing fault currents is crucial for avoiding damage to equipment as ...

2006-11-28T23:59:59.000Z

248

Fault Tree Based Diagnostics Using Fuzzy Logic  

Science Conference Proceedings (OSTI)

Fuzzy set theory is investigated as a tool for the diagnostics of systems described by means of a fault tree. The objective is to diagnose component failures from the observation of fuzzy symptoms using the information contained in a fault tree. A two-step ... Keywords: causal reasoning, component failures, failure analysis, failure modes, fault tree based diagnostics, fuzzy logic, fuzzy symptoms, minimal cut-sets, triggered gates, two-step procedure

P. Gmytrasiewicz; J. A. Hassberger; J. C. Lee

1990-11-01T23:59:59.000Z

249

Wormhole formation in dissolving fractures  

E-Print Network (OSTI)

We investigate the dissolution of artificial fractures with three-dimensional, pore-scale numerical simulations. The fluid velocity in the fracture space was determined from a lattice-Boltzmann method, and a stochastic solver was used for the transport of dissolved species. Numerical simulations were used to study conditions under which long conduits (wormholes) form in an initially rough but spatially homogeneous fracture. The effects of flow rate, mineral dissolution rate and geometrical properties of the fracture were investigated, and the optimal conditions for wormhole formation determined.

Szymczak, P

2009-01-01T23:59:59.000Z

250

Development Opportunity Zone Credit  

Energy.gov (U.S. Department of Energy (DOE))

The Development Opportunity Zone Credits incent new and expanding businesses in the Cities of Beloit, Janesville and Kenosha by providing non-refundable tax credits to assist with the creation and...

251

Keystone Opportunity Zones (Pennsylvania)  

Energy.gov (U.S. Department of Energy (DOE))

Keystone Opportunity Zones allows businesses located within designated areas to qualify for a tax exemption, deduction, credit, or abatement of state and local taxes such as sales and use tax,...

252

Deep Vadose Zone  

Energy.gov (U.S. Department of Energy (DOE))

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...

253

Fault diagnosis in reversible circuits under missing-gate fault model  

Science Conference Proceedings (OSTI)

This article presents a novel technique for fault detection as well as fault location in a reversible combinational circuit under the missing gate fault model. It is shown that in an (nxn) reversible circuit implemented with k-CNOT gates, addition of ...

Hafizur Rahaman; Dipak K. Kole; Debesh K. Das; Bhargab B. Bhattacharya

2011-07-01T23:59:59.000Z

254

Queen Anne's County- Solar Zoning  

Energy.gov (U.S. Department of Energy (DOE))

Queen Anne's County zoning code allows for ground mounted solar arrays in areas zoned as "open space," "agricultural," and "countryside" districts.

255

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

SciTech Connect

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.

Mattiozzi, Pierpaolo [Snamprogetti-Saipem, Via Toniolo, 1, 61032 Fano (Italy); Strom, Alexander [Institute of Geospheres Dynamics, Leninskiy Avenue, 38, Building 1, 119334, Moscow (Russian Federation)

2008-07-08T23:59:59.000Z

256

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

Science Conference Proceedings (OSTI)

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.

Vitali, Luigino [Snamprogetti-Saipem, Via Toniolo, 1, 61032 Fano, Luigino (Italy); Mattiozzi, Pierpaolo [Snamprogetti-Saipem, Via Toniolo, 1, 61032 Fano (Italy)

2008-07-08T23:59:59.000Z

257

Interferometric hydrofracture microseism localization using neighboring fracture  

E-Print Network (OSTI)

Hydraulic fracturing is the process of injecting high-pressure fluids into a reservoir to induce fractures and thus improve reservoir productivity. Microseismic event localization is used to locate created fractures. ...

Poliannikov, Oleg V.

258

Evaluation of fracturing results in deviated wellbores through on-site measurements  

SciTech Connect

Four adjacent oil wells in the Kuparuk River oil field, with deviated angles of 6{sup 0}5', 24{sup 0}6', 27{sup 0} and 36{sup 0}7' from the vertical at the perforations, were analyzed with prefracturing tests. The total fluid volume for these tests varied from 645 to 840 bbl(103 to 134 m/sup 3/) of either clean lease oil or water-based fracturing fluid at low to intermediate rates (up to 15bbl/min(2.4m/sup 3/)). These wells were subsequently fractured with proppant-laden fluid. A series of instantaneous shut-in pressures (ISIO's) was obtained for each well. ISIP's and fracturing pressures decreased with time in two of the four wells with a relatively high friction pressure at the end of the pumping. A radially propagating fracture from a point source of pressure explains this decreasing pressure with time. The elasticity theory predicts that a fracture in a deviated, cased wellbore should intersect the wellbore at one location. Only when the deviated wellbore azimuth is near that of the fracture orientation does the fracture sweep the entire perforated zone. This observation of the fracture orientation relative to the wellbore azimuth based on the pressure analysis is enhanced further by postfracture temperature surveys. It appears that only a relatively small volume of proppant could be displaced in a deviated wellbore. The degree of deviation, however, did not appear to be a major concern in the treatment of size.

Kim, C.M. (Halliburton Services, Duncan, OK (USA)); Champion, J.H. (Arco Alaska Inc. (US)); Cooper, G.D. (Guydon Software Services (US))

1989-08-01T23:59:59.000Z

259

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

Science Conference Proceedings (OSTI)

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.

Shah, S.; Zhoi, Y.X.; Bailey, M.; Hernandez, J. [University of Oklahoma, Norman, OK (United States)

2009-08-15T23:59:59.000Z

260

Deficiencies in Vadose Zone Understanding at the INEEL  

Science Conference Proceedings (OSTI)

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.

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

2000-08-01T23:59:59.000Z

Note: This page contains sample records for the topic "fracture zones faults" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


261

Meshless animation of fracturing solids  

Science Conference Proceedings (OSTI)

We present a new meshless animation framework for elastic and plastic materials that fracture. Central to our method is a highly dynamic surface and volume sampling method that supports arbitrary crack initiation, propagation, and termination, while ... Keywords: elasticity, fracture, meshless methods, physics-based animation, plasticity

Mark Pauly; Richard Keiser; Bart Adams; Philip Dutré; Markus Gross; Leonidas J. Guibas

2005-07-01T23:59:59.000Z

262

NETL: Discrete Fracture Reservoir Simulation Software  

NLE Websites -- All DOE Office Websites (Extended Search)

Discrete Fracture Reservoir Simulation FRACGENNFFLOW Shale Gas Flow Simulation Shale Gas Flow Simulation FRACGENNFFLOW, a fractured reservoir modeling software developed by the...

263

Self-potential observations during hydraulic fracturing  

E-Print Network (OSTI)

and T. W. Keech (1977), Hydraulic fracture mapping usingpotential measurements during hydraulic fracturing of Bunterbetween electrical and hydraulic flow patterns from rock

Moore, J R; Glaser, Steven D

2007-01-01T23:59:59.000Z

264

Some Fundamental Mechanisms of Hydraulic Fracturing .  

E-Print Network (OSTI)

??This dissertation focuses mainly on three topics: (1) mixed-mode branching and segmentation of hydraulic fractures in brittle materials, (2) hydraulic fracture propagation in particulate materials,… (more)

Wu, Ruiting

2006-01-01T23:59:59.000Z

265

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

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

Centers Field Sites Power Marketing Administration Other Agencies You are here Home Shale Gas Development Challenges: Fracture Fluids Shale Gas Development Challenges: Fracture...

266

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

Science Conference Proceedings (OSTI)

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.

Buss, Heather [University of Bristol, UK; Brantley, S. L. [Pennsylvania State University, University Park, PA; Scatena, Fred [University of Pennsylvania; Bazilevskaya, Ekaterina [Pennsylvania State University, University Park, PA; Blum, Alex [U. S. Geological Survey, Boulder, CO; Schulz, M [University of Pennsylvania; Jimenez, M [University of Pennsylvania; White, Art [U.S. Geological Survey, Menlo Park, CA; Cole, David [Ohio State University

2013-01-01T23:59:59.000Z

267

“Hanging” Pelvic Gallbladder Simulating Occult Hip Fracture Versus Appendicitis  

E-Print Network (OSTI)

Pelvic Gallbladder Simulating Occult Hip Fracture Versuspossibility of either an occult hip fracture or a subacute

Dolbec, Katherine W D; Higgins, George L; Jung, Michale W

2010-01-01T23:59:59.000Z

268

Downhole tool sniffs out fractures  

SciTech Connect

This article reports that a new tool has been designed and successfully tested that can designate which direction from a borehole a particular fracture is located. Albuquerque-based Sandia National Laboratories tested the new tool. The prototype was built by Southwest Research Institute of San Antonio. During field tests, the tool detected simulated fractures more than 30 ft away from a test borehole. It determines fracture direction by transmitting highly directional and powerful radar pulses in a known direction. The pulses last eight billionths of a second and their frequency spectrum range up to the VHF (very high frequency) band. Discontinuities in the rock interrupt and reflect radar signals so that a signal's return to the tool indicates the presence of fractures. The return signal's time delay translates into distance from the borehole. The transmitter and receiver rotate in place, permitting the tool to scan for fractures in all directions.

Not Available

1987-05-01T23:59:59.000Z

269

Distribution Fault Location Support Tools, Algorithms, and Implementation Approaches  

Science Conference Proceedings (OSTI)

Distribution grid modernization applications such as fault location and automatic sectionalizing require an accurate assessment of fault current. More-accurate prediction of fault locations will shorten the fault investigation (patrol) time, which in turn can reduce the total restoration time and duration of the outage experienced by the customer. This EPRI technical update report presents information on fault location applications, enumerates different methods used to detect the location of faults, ...

2013-08-14T23:59:59.000Z

270

ARMor: fully verified software fault isolation  

Science Conference Proceedings (OSTI)

We have designed and implemented ARMor, a system that uses software fault isolation (SFI) to sandbox application code running on small embedded processors. Sandboxing can be used to protect components such as the RTOS and critical control loops from ... Keywords: arm executables, automated theorem proving, program logic, software fault isolation

Lu Zhao; Guodong Li; Bjorn De Sutter; John Regehr

2011-10-01T23:59:59.000Z

271

A switch level fault simulation environment  

Science Conference Proceedings (OSTI)

This paper presents a fault simulation environment which accepts pure switch level or mixed switch/RT level descriptions of the design under test. Switch level fault injection strategies for the stuck-at, transition and logic bridge models are presented. ...

V. Krishnaswamy; J. Casas; T. Tetzlaff

2000-06-01T23:59:59.000Z

272

Representing parameterised fault trees using Bayesian networks  

Science Conference Proceedings (OSTI)

Fault trees are used to model how failures lead to hazards and so to estimate the frequencies of the identified hazards of a system. Large systems, such as a rail network, do not give rise to endless different hazards. Rather, similar hazards arise repeatedly ... Keywords: Bayesian network, fault tree, risk analysis

William Marsh; George Bearfield

2007-09-01T23:59:59.000Z

273

Gas Turbine Fault Diagnosis using Random Forests  

Science Conference Proceedings (OSTI)

In the present paper, Random Forests are used in a critical and at the same time non trivial problem concerning the diagnosis of Gas Turbine blading faults, portraying promising results. Random forests-based fault diagnosis is treated as a Pattern Recognition ...

Manolis Maragoudakis; Euripides Loukis; Panayotis-Prodromos Pantelides

2008-06-01T23:59:59.000Z

274

BASE: Using abstraction to improve fault tolerance  

Science Conference Proceedings (OSTI)

Software errors are a major cause of outages and they are increasingly exploited in malicious attacks. Byzantine fault tolerance allows replicated systems to mask some software errors but it is expensive to deploy. This paper describes a replication ... Keywords: Byzantine fault tolerance, N-version programming, asynchronous systems, proactive recovery, state machine replication

Miguel Castro; Rodrigo Rodrigues; Barbara Liskov

2003-08-01T23:59:59.000Z

275

Numeric simulation of faults in electrical networks  

Science Conference Proceedings (OSTI)

In the paper is presented a virtual simulator for three-phased medium voltage electric circuits. The simulator allows analyzing transient regimes caused by the faults produced in electric distribution networks (simple grounding, double grounding, broken ... Keywords: faults in electric network, numerical simulation, three phased circuits, transient regimes

Toader Dumitru; Haragus Stefan; Blaj Constantin

2009-03-01T23:59:59.000Z

276

INDUCTION MOTOR FAULT DIAGNOSTIC AND MONITORING METHODS  

E-Print Network (OSTI)

INDUCTION MOTOR FAULT DIAGNOSTIC AND MONITORING METHODS by Aderiano M. da Silva, B.S. A Thesis;i Abstract Induction motors are used worldwide as the "workhorse" in industrial applications material. However, induction motor faults can be detected in an initial stage in order to prevent

Povinelli, Richard J.

277

Active and passive seismic imaging of a hydraulic fracture in diatomite  

SciTech Connect

This paper reports on a comprehensive set of experiments including remote- and treatment-well microseismic monitoring, interwell shear-wave shadowing, and surface tiltmeter arrays, that was used to monitor the growth of a hydraulic fracture in the Belridge diatomite. To obtain accurate measurements, and extensive subsurface network of geophones was cemented spanning the diatomite formation in three closely spaced observation wells around the well to be fracture treated. Data analysis indicates that the minifracture and main hydraulic fracture stimulations resulted in a nearly vertical fracture zone (striking N26{degrees}E) vertically segregated into two separate elements, the uppermost of which grew 60 ft above the perforated interval. The interwell seismic effects are consistent with a side process zone of reduced shear velocity, which remote-well microseismic data independently suggest may be as wide as 40 ft. The experiments indicate complicated processes occurring during hydraulic fracturing that have significant implications for stimulation, waterflooding, in fill drilling, and EOR. These processes are neither well understood nor included in current hydraulic fracture models.

Vinegar, H.J.; Wills, P.B.; De Martini, D.C. (Shell Development Co. (US))

1992-01-01T23:59:59.000Z

278

Lisburne Formation fracture characterization and flow modeling  

E-Print Network (OSTI)

Evaluation of fractured reservoirs for fluid flow and optimal well placement is often very complicated. In general, fractures enhance permeability and increase access to matrix surface, but their random aspects create difficulties for analysis and performance prediction. Each reservoir has unique aspects which require individual assessment. This study examined fracture properties in a part of the Carboniferous Lisburne Formation. Field study of outcrops yielded information on two sets of large-scale fractures (NNW and ENE orientations) from the lower Wahoo Limestone in the eastern Sadlerochit Mountains. Several statistical methods were used on these data to find appropriate models describing the megafracture properties. For NNW fracture height and ENE fracture spacing, the gamma model appears to adequately describe the distribution. NNW fracture spacing and ENE fracture height are lognormally distributed. Results of the statistical analyses were used as input for fracture set generation and modeling using "FracMan". Modeling different borehole orientations in the fractured domain revealed that horizontal wells with 60? azimuth have an optimal trajectory, resulting in the maximum number and area of fracture connections. The orientation maximizing the number of fracture connections did not necessarily give the maximum area. Conductivity analysis showed that the fracture network is weakly anisotropic and above the percolation threshold. The fracture conductance is strongly dependent on the NNW fracture set; larger fractures influence fluid flow more than smaller fractures. Fracture strike and dip variability increased the system interconnectivity, but did not affect the optimal wellbore orientation. Incorporating ENE fracture termination against the NNW fractures decreased the system conductance and shifted the optimal wellbore trajectory towards the direction perpendicular to the NNW set. Reservoir engineering implications of this study include: guidelines for optimal wellbore orientations, the relative placement of injectors and producers along the bisectors between the two fracture sets, and the importance of including fracture terminations. Further work should investigate the influence of variations in fracture aperture and transmissivities, and drainage area, and extend the analysis to additional units of the Lisburne Group.

Karpov, Alexandre Valerievich

2001-01-01T23:59:59.000Z

279

Gradient effects on the fracture of inhomogeneous materials  

SciTech Connect

Functionally Graded Materials (FGMs) have a spatial variation in physical properties that can be tailored to meet the needs of a specific application and/or to minimize internal stresses arising from thermal and elastic mismatch. Modeling these materials as inhomogeneous continua allows assessment of the role of the gradient without requiring detailed knowledge of the microstructure. Motivated by the relative difficulty of obtaining analytical solutions to boundary value problems for FGMs, an accurate finite-element code is developed for obtaining numerical planar and axisymmetric linear thermoelastic solutions. In addition an approximate analytical technique for mapping homogeneous-modulus solutions to those for FGMs is assessed and classes of problems to which it applies accurately are identified. The fracture mechanics analysis of FGMs can be characterized by the classic stress intensities, KI and KII, but there has been scarce progress in understanding the role of the modulus gradient in determining fracture initiation and propagation. To address this question, a statistical fracture model is used to correlate near-tip stresses with brittle fracture initiation behavior. This describes the behavior of a material experiencing fracture initiation away from the crack tip. Widely dispersed zones of fracture initiation sites are expected. Finite-length kinks are analyzed to describe the crack path for continuous crack growth. For kink lengths much shorter than the gradient dimension, a parallel stress term describes the deviation of the kinking angle from that for homogeneous materials. For longer kinks there is a divergence of the kink angle predicted by the maximum energy release rate and the pure opening mode criteria.

Becker, T.L.

2000-05-01T23:59:59.000Z

280

Relative Permeability of Fractured Rock  

DOE Green Energy (OSTI)

Contemporary understanding of multiphase flow through fractures is limited. Different studies using synthetic fractures and various fluids have yielded different relative permeability-saturation relations. This study aimed to extend the understanding of multiphase flow by conducting nitrogen-water relative permeability experiments on a naturally-fractured rock from The Geysers geothermal field. The steady-state approach was used. However, steady state was achieved only at the endpoint saturations. Several difficulties were encountered that are attributed to phase interference and changes in fracture aperture and surface roughness, along with fracture propagation/initiation. Absolute permeabilities were determined using nitrogen and water. The permeability values obtained change with the number of load cycles. Determining the absolute permeability of a core is especially important in a fractured rock. The rock may change as asperities are destroyed and fractures propagate or st rain harden as the net stresses vary. Pressure spikes occurred in water a solute permeability experiments. Conceptual models of an elastic fracture network can explain the pressure spike behavior. At the endpoint saturations the water relative permeabilities obtained are much less than the nitrogen gas relative permeabilities. Saturations were determined by weighing and by resistivity calculations. The resistivity-saturation relationship developed for the core gave saturation values that differ by 5% from the value determined by weighing. Further work is required to complete the relative permeability curve. The steady-state experimental approach encountered difficulties due to phase interference and fracture change. Steady state may not be reached until an impractical length of time. Thus, unsteady-state methods should be pursued. In unsteady-state experiments the challenge will be in quantifying rock fracture change in addition to fluid flow changes.

Mark D. Habana

2002-06-30T23:59:59.000Z

Note: This page contains sample records for the topic "fracture zones faults" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


281

Detect and classify faults using neural nets  

SciTech Connect

The analysis of transmission line faults is essential to the proper performance of the power system. It is required if protective relays are to take the appropriate action and in monitoring the performance of relays, circuit breakers, and other protective and control elements. The detection and classification of transmission line faults is a fundamental component of such fault analysis. Another application of fault analysis is in software packages for automated analysis of digital fault recorder (DFR) files. Recently, such a package, called DFR Assistant, was developed for substation applications. This program can be installed locally in a substation, in which case it is connected directly to the DFR via a high speed parallel link, or it can be installed at a central station, in which case it can be configured to automatically analyze events coming from all DFRs.

Kezunovic, M.; Rikalo, I.

1996-10-01T23:59:59.000Z

282

Modeling and Measurement Constraints in Fault Diagnostics for HVAC Systems  

E-Print Network (OSTI)

in Fault Diagnostics for HVAC Systems Massieh Najafi 1 ,tools for determining HVAC diagnostics, methods todetect faults in HVAC systems are still generally

Najafi, Massieh

2010-01-01T23:59:59.000Z

283

Modeling and simulation of HVAC faults in EnergyPlus  

NLE Websites -- All DOE Office Websites (Extended Search)

simulation of HVAC faults in EnergyPlus Title Modeling and simulation of HVAC faults in EnergyPlus Publication Type Conference Paper Refereed Designation Refereed Year of...

284

Modeling and Measurement Constraints in Fault Diagnostics for...  

NLE Websites -- All DOE Office Websites (Extended Search)

Modeling and Measurement Constraints in Fault Diagnostics for HVAC Systems Title Modeling and Measurement Constraints in Fault Diagnostics for HVAC Systems Publication Type Journal...

285

fault diagnosis of a high voltage transmission line using waveform ...  

E-Print Network (OSTI)

Oct 4, 2013 ... FAULT DIAGNOSIS OF A HIGH VOLTAGE TRANSMISSION LINE USING ... Fault types such as single line to ground, line to line, double line to ...

286

CIFTS: Coordinated Infrastructure for Fault-Tolerant Systems...  

NLE Websites -- All DOE Office Websites (Extended Search)

CIFTS: Coordinated Infrastructure for Fault-Tolerant Systems CIFTS: Coordinated Infrastructure for Fault-Tolerant Systems Current systems software components for large-scale...

287

CIFTS: A Coordinated Infrastructure for Fault-Tolerant Systems...  

NLE Websites -- All DOE Office Websites (Extended Search)

CIFTS: A Coordinated Infrastructure for Fault-Tolerant Systems Title CIFTS: A Coordinated Infrastructure for Fault-Tolerant Systems Publication Type Conference Paper Year of...

288

Progress toward using hydraulic data to diagnose lost circulation zones  

DOE Green Energy (OSTI)

Several wellbore hydraulic models have been examined to determine their applicability in measuring the characteristics of lost circulation zones encountered in geothermal drilling. Characteristics such as vertical location in the wellbore, fracture size, effective permeability, and formation pressure must be known in order to optimize treatment of such zones. The models that have been examined to date are a steady-state model, a standpipe-pressure model, a raising-the-drill-bit model, a mud-weight model, a hydrofracture model, and several time-dependent models. None of these models yet have been found to adequately match the field data obtained from six loss zones in three geothermal wells. The development of these models is presented in this paper, and a discussion of their limitations is provided.

Mansure, A.J.; Glowka, D.A.

1995-07-01T23:59:59.000Z

289

Automated Fault Location In Smart Distribution Systems  

E-Print Network (OSTI)

Fault location in distribution systems is a critical component of outage management and service restoration, which directly impacts feeder reliability and quality of the electricity supply. Improving fault location methods supports the Department of Energy (DOE) “Grid 2030” initiatives for grid modernization by improving reliability indices of the network. Improving customer average interruption duration index (CAIDI) and system average interruption duration index (SAIDI) are direct advantages of utilizing a suitable fault location method. As distribution systems are gradually evolving into smart distribution systems, application of more accurate fault location methods based on gathered data from various Intelligent Electronic Devices (IEDs) installed along the feeders is quite feasible. How this may be done and what is the needed methodology to come to such solution is raised and then systematically answered. To reach this goal, the following tasks are carried out: 1) Existing fault location methods in distribution systems are surveyed and their strength and caveats are studied. 2) Characteristics of IEDs in distribution systems are studied and their impacts on fault location method selection and implementation are detailed. 3) A systematic approach for selecting optimal fault location method is proposed and implemented to pinpoint the most promising algorithms for a given set of application requirements. 4) An enhanced fault location method based on voltage sag data gathered from IEDs along the feeder is developed. The method solves the problem of multiple fault location estimations and produces more robust results. 5) An optimal IED placement approach for the enhanced fault location method is developed and practical considerations for its implementation are detailed.

Lotfifard, Saeed

2011-08-01T23:59:59.000Z

290

Near-field/altered-zone models report  

Science Conference Proceedings (OSTI)

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

Hardin, E. L., LLNL

1998-03-01T23:59:59.000Z

291

Fracturing Fluid Characterization Facility  

NLE Websites -- All DOE Office Websites (Extended Search)

Documentation Page Documentation Page 1. Report No. DE - FC 21 - 92MC29077 2. 3. Recipient's Accession No. 5. Report Date August 31, 2000 4. Title and Subtitle Fracturing Fluid Characterization Facility 6. 7. Author(s) The University of Oklahoma 8. Performing Organization Rept. No. 10. Project/Task/Work Unit No. 9. Performing Organization Name and Address The University of Oklahoma Sarkeys Energy Center T301 100 E Boyd St Norman, OK 73019 11. Contract (C) or Grant (G) No. DOE:DE FC21 92 MC29077 13. Type of Report & Period Covered Final Report 09 30 92 - 03 31 00 12. Sponsoring Organization Name and Address US Dept of Energy - FETL 3610 Collins Ferry Road Morgantown, WV 26505 14. 15. Supplementary Notes Several technical papers were prepared and presented at various Society of Petroleum Engineers Conferences and US

292

An arc fault detection system  

DOE Patents (OSTI)

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.

Jha, Kamal N.

1997-12-01T23:59:59.000Z

293

Fault diagnosis using substation computer  

SciTech Connect

A number of substation integrated control and protection systems (ICPS) are being developed around the world, where the protective relaying, control, and monitoring functions of a substation are implemented using microprocessors. In this design, conventional relays and control devices are replaced by clusters of microprocessors, interconnected by multiplexed digital communication channels using fibre optic, twisted wire pairs or coaxial cables. The ICPS incorporates enhanced functions of value to the utility and leads to further advancement of the automation of transmission substations. This paper presents an automated method of fault diagnosis which can be incorporated in the station computer of an integrated control and protection system. The effectiveness of this method is demonstrated using a transmission-level substation as an example.

Jeyasurya, B. (Indian Inst. of Tech., Bombay (India)); Venkata, S.S. (Washington Univ., Seattle, WA (USA). Dept. of Electrical Engineering); Vadari, S.V. (ESCA Corp., Bellevue, WA (USA)); Postforoosh, J. (T and D. Protection Group, Puget Sound Power and Light, Bellevue, WA (US))

1990-04-01T23:59:59.000Z

294

SPALL FRACTURE AND SPALL FRACTURE AND COMPACTION COMPACTION  

National Nuclear Security Administration (NNSA)

SPALL FRACTURE AND SPALL FRACTURE AND SPALL FRACTURE AND SPALL FRACTURE AND COMPACTION COMPACTION IN NATURAL URANIUM IN NATURAL URANIUM UNDER SHOCK UNDER SHOCK - - WAVE LOADING WAVE LOADING O.A. O.A. Tyupanova Tyupanova , S.S. , S.S. Nadezhin Nadezhin , A.N. , A.N. Malyshev Malyshev , , O.N. O.N. Ignatova Ignatova , V.I. , V.I. Skokov Skokov , V.N. , V.N. Knyazev Knyazev , , V.A. V.A. Raevsky Raevsky , N.A. , N.A. Yukina Yukina Russian Federal Nuclear Center Russian Federal Nuclear Center - - VNIIEF, VNIIEF, Sarov Sarov , Russia , Russia Introduction Introduction  Nucleation and growth of defects inside a solid under pulse tensile stresses signify a necessity to consider it as a damaged medium.  A certain volume of experimental data, obtained in correct tests, which are sensitive to a characteristic under study, is necessary

295

Subduction Zone | Open Energy Information  

Open Energy Info (EERE)

Subduction Zone Subduction Zone Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Print PDF Subduction Zone Dictionary.png Subduction Zone: A tectonic process in which one tectonic plate is forced beneath another and sinks into the mantle as the plates converge Other definitions:Wikipedia Reegle Tectonic Settings List of tectonic settings known to host modern geothermal systems: Extensional Tectonics Subduction Zone Rift Zone Hot Spot Non-Tectonic Strike-Slip A classic cartoon illustrating a typical simplified subduction zone. http://www.columbia.edu/~vjd1/subd_zone_basic.htm Subduction zones occur where one tectonic plate is pulled under another. Most often the subducting plate is oceanic crust and contains many hydrous minerals. As the oceanic plate subducts it dewaters into the mantle,

296

Contact zones and hydrothermal systems as analogues to repository conditions  

SciTech Connect

Radioactive waste isolation efforts in the US are currently focused on examining basalt, tuff, salt, and crystalline rock as candidate rock types to encompass waste repositories. As analogues to near-field conditions, the distributions of radio- and trace-elements have been examined across contacts between these rocks and dikes and stocks that have intruded them. The intensive study of the Stripa quartz monzonite has also offered the opportunity to observe the distribution of uranium and its daughters in groundwater and its relationship to U associated with fracture-filling and alteration minerals. Investigations of intrusive contact zones to date have included (1) a tertiary stock into Precambrian gneiss, (2) a stock into ash flow tuff, (3) a rhyodacite dike into Columbia River basalt, and (4) a kimberlite dike into salt. With respect to temperature and pressure, these contact zones may be considered "worst-case scenario" analogues. Results indicate that there has been no appreciable migration of radioelements from the more radioactive intrusives into the less radioactive country rocks, either in response to the intrusions or in the fracture-controlled hydrological systems that developed following emplacement. In many cases, the radioelements are locked up in accessory minerals, suggesting that artificial analogues to these would make ideal waste forms. Emphasis should now shift to examination of active hydrothermal systems, studying the distribution of key elements in water, fractures, and alteration minerals under pressure and temperature conditions most similar to those expected in the near-field environment of a repository. 14 refs.

Wollenberg, H.A.; Flexser, S.

1984-10-01T23:59:59.000Z

297

Advanced Vadose Zone Simulations Using TOUGH  

E-Print Network (OSTI)

multiphase flow and multicomponent transport in porous andmultiphase, multicomponent fluids in permeable (fractured and porous)multiphase fluid flow, heat transfer, and deformation in fractured porous

2008-01-01T23:59:59.000Z

298

Advanced Vadose Zone Simulations Using TOUGH  

E-Print Network (OSTI)

for modeling fluid and heat flow in fractured porous media.flows of multiphase, multicomponent fluids in permeable (fractured and porous) media (

2008-01-01T23:59:59.000Z

299

Cooperative application/OS DRAM fault recovery.  

Science Conference Proceedings (OSTI)

Exascale systems will present considerable fault-tolerance challenges to applications and system software. These systems are expected to suffer several hard and soft errors per day. Unfortunately, many fault-tolerance methods in use, such as rollback recovery, are unsuitable for many expected errors, for example DRAM failures. As a result, applications will need to address these resilience challenges to more effectively utilize future systems. In this paper, we describe work on a cross-layer application/OS framework to handle uncorrected memory errors. We illustrate the use of this framework through its integration with a new fault-tolerant iterative solver within the Trilinos library, and present initial convergence results.

Ferreira, Kurt Brian; Bridges, Patrick G. (University of New Mexico, Albuquerque, NM); Heroux, Michael Allen; Hoemmen, Mark; Brightwell, Ronald Brian

2012-05-01T23:59:59.000Z

300

Mechanical Models of Fault-Related Folding  

SciTech Connect

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).

Johnson, A. M.

2003-01-09T23:59:59.000Z

Note: This page contains sample records for the topic "fracture zones faults" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


301

Determining the 3-D fracture structure in the Geysers geothermal reservoir  

DOE Green Energy (OSTI)

The bulk of the steam at the Geysers geothermal field is produced from fractures in a relatively impermeable graywacke massif which has been heated by an underlying felsite intrusion. The largest of these fractures are steeply dipping right lateral strike-slip faults which are subparallel to the NW striking Collayomi and Mercuryville faults which form the NE and SW boundaries of the known reservoir. Where the graywacke source rock outcrops at the surface it is highly sheared and fractured over a wide range of scale lengths. Boreholes drilled into the reservoir rock encounter distinct ''steam entries'' at which the well head pressure jumps from a few to more than one hundred psi. This observation that steam is produced from a relatively small number of major fractures has persuaded some analysts to use the Warren and Root (1963) dual porosity model for reservoir simulation purposes. The largest fractures in this model are arranged in a regular 3-D array which partitions the reservoir into cubic ''matrix'' blocks. The net storage and transport contribution of all the smaller fractures in the reservoir are lumped into average values for the porosity and permeability of these matrix blocks which then feed the large fractures. Recent improvements of this model largely focus on a more accurate representation of the transport from matrix to fractures (e.g. Pruess et al., 1983; Ziminerman et al., 1992), but the basic geometry is rarely questioned. However, it has long been recognized that steam entries often occur in clusters separated by large intervals of unproductive rock (Thomas et al., 1981). Such clustering of fixtures at all scale lengths is one characteristic of self-similar distributions in which the fracture distribution is scale-independent. Recent studies of the geometry of fracture networks both in the laboratory and in the field are finding that such patterns are self-similar and can be best described using fractal geometry. Theoretical simulations of fracture development in heterogeneous media also produce fractal patterns. However, a physical interpretation of the mechanics which produce the observed fractal geometry remains an active area of current research. Two hypotheses for the physical cause of self-similarity are the Laplacian growth of fractures in a self-organized critical stress field, and the evolution of percolation clusters in a random medium. Each predicts a different, fractal dimension. The more important questions from a reservoir engineering point of view are: (1) is the network of fractures in the Geysers reservoir fractal and if so over what range of fracture sizes is the self-similarity observed and what is its fractal dimension, and (2) do the conventional dual porosity numerical simulation schemes provide an adequate description of flow and heat mining at the Geysers? Other papers in this volume by Acuna, Ershaghi, and Yortsos (1992) and Mukhopodhyoy and Sahimi (1992) address the second question. The primary objective of this paper is to try to answer the first. Toward this goal we have mapped fracture patterns in surface exposures of the graywacke source rock at the outcrop scale (meters), at the road-cut scale (tens of meters) and at the regional scale (kilometers). We have also examined cores collected at depth from the graywacke reservoir rocks, and analyzed drilling logs making use of the pattern of steam entries as well as the fluctuations in drilling rate.

Sammis, Charles G.; Linji An; Iraj Ershaghi

1992-01-01T23:59:59.000Z

302

Fracture of aluminum naval structures  

E-Print Network (OSTI)

Structural catastrophic failure of naval vessels due to extreme loads such as underwater or air explosion, high velocity impact (torpedoes), or hydrodynamic loads (high speed vessels) is primarily caused by fracture. ...

Galanis, Konstantinos, 1970-

2007-01-01T23:59:59.000Z

303

Fracture detection and mapping for geothermal reservoir definition: an assessment of current technology, research, and research needs  

DOE Green Energy (OSTI)

The detection and mapping of fractures and other zones of high permeability, whether natural or manmade, has been a subject of considerable economic and scientific interest to the pertroleum industry and to the geothermal community. Research related to fractured geothermal reservoirs has been conducted under several past DOE geothermal energy development programs. In this paper we review the present state of technology in fracture detection and mapping. We outline the major problems and limitations of the ''conventional'' techniques, and current research in new technologies. We also present research needs.

Goldstein, N.E.

1984-11-01T23:59:59.000Z

304

Temporary Sealing of Fractures | Open Energy Information  

Open Energy Info (EERE)

Temporary Sealing of Fractures Temporary Sealing of Fractures Jump to: navigation, search Contents 1 Geothermal Lab Call Projects for Temporary Sealing of Fractures 2 Geothermal ARRA Funded Projects for Temporary Sealing of Fractures Geothermal Lab Call Projects for Temporary Sealing of Fractures Loading map... {"format":"googlemaps3","type":"ROADMAP","types":["ROADMAP","SATELLITE","HYBRID","TERRAIN"],"limit":200,"offset":0,"link":"all","sort":[""],"order":[],"headers":"show","mainlabel":"","intro":"","outro":"","searchlabel":"\u2026

305

Neural Fault Diagnosis and Fuzzy Fault Control for a Complex Dynamic System  

E-Print Network (OSTI)

Fault diagnosis has become an issue of primary importance in modern process automation as it provides the prerequisites for the task of fault detection. The ability to detect the faults is essential to improve reliability and security of a complex control system. Parameter estimation methods, state observation schemes, statistical likelihood ratio tests, rule-based expert system reasoning, pattern recognition techniques, and artificial neural network approaches are the most common methodologies developed actively during recent years. In this paper, we describe a completed feasibility study demonstrating the merit of employing pattern recognition and an artificial neural network for fault diagnosis through back propagation learning algorithm and making the use of fuzzy approximate reasoning for fault control via parameter changes in a dynamic system. As a test case, a complex magnetic levitation vehicle (MLV) system is studied. Analytical fault symptoms are obtained by system dynamics m...

Ching-yu Tyan; Paul P. Wang; Dennis R. Bahler

1995-01-01T23:59:59.000Z

306

Ductile Fracture Handbook: Volume 2  

Science Conference Proceedings (OSTI)

The three-volume Ductile Fracture Handbook provides the structural analyst with computational methods for evaluating the integrity of flawed structures that are fabricated from ductile materials or have loads that may produce significant plasticity, specifically easy-to-use fracture mechanics solutions for a wide range of problems dealing with cylinders subjected to several types of elastic-plastic loading. Volume 2 presents new solutions and significant expansion of previous solutions, typically in the ...

1990-09-01T23:59:59.000Z

307

Ductile Fracture Handbook: Volume 3  

Science Conference Proceedings (OSTI)

The three-volume Ductile Fracture Handbook provides the structural analyst with computational methods for evaluating the integrity of flawed structures that are fabricated from ductile materials or have loads that may produce significant plasticity, specifically easy-to-use fracture mechanics solutions for a wide range of problems dealing with cylinders subjected to several types of elastic-plastic loading. Volume 3 presents solutions for axial part-throughwall cracks, cracks in elbows, tees, and nozzles...

1990-09-01T23:59:59.000Z

308

Quantification of Priority-OR gates in temporal fault trees  

Science Conference Proceedings (OSTI)

Fault Tree Analysis has been used in reliability engineering for many decades and has seen various modifications to enable it to analyse fault trees with dynamic and temporal gates so it can incorporate sequential failure in its analysis. Pandora is ... Keywords: Markov chains, Monte Carlo, Pandora, dynamic fault trees, fault trees, safety

Ernest Edifor; Martin Walker; Neil Gordon

2012-09-01T23:59:59.000Z

309

Online fault detection and tolerance for photovoltaic energy harvesting systems  

Science Conference Proceedings (OSTI)

Photovoltaic energy harvesting systems (PV systems) are subject to PV cell faults, which decrease the efficiency of PV systems and even shorten the PV system lifespan. Manual PV cell fault detection and elimination are expensive and nearly impossible ... Keywords: fault detection, fault tolerance, photovoltaic panel reconfiguration, photovoltaic system

Xue Lin; Yanzhi Wang; Di Zhu; Naehyuck Chang; Massoud Pedram

2012-11-01T23:59:59.000Z

310

A transmission line fault locator based on Elman recurrent networks  

Science Conference Proceedings (OSTI)

In this paper, a transmission line fault location model which is based on an Elman recurrent network (ERN) has been presented for balanced and unbalanced short circuit faults. All fault situations with different inception times are implemented on a 380-kV ... Keywords: Elman networks, Fault location, Transmission lines, Wavelet transform

Sami Ekici; Selcuk Yildirim; Mustafa Poyraz

2009-01-01T23:59:59.000Z

311

NaturAnalogs for the Unsaturated Zone  

Science Conference Proceedings (OSTI)

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.

A. Simmons; A. Unger; M. Murrell

2000-03-08T23:59:59.000Z

312

Fault intersections and hybrid transform faults in the southern Salton Trough geothermal area, Baja California, Mexico  

DOE Green Energy (OSTI)

Analysis of 55 wells drilled at the Cerro Prieto Geothermal Field and a suite of geological and geophysical studies throughout the southern Salton Trough from the Mexican-United States border to the Gulf of California clarify two concepts important to geothermal development: (1) increased natural convective fluid flow and better permeability should occur at intersecting faults both regionally and within a producing field, and (2) the Cerro Prieto and Imperial faults are best conceived of as hybrid types having features of both San Andreas style wrench faults and oceanic tranform faults.

Vonder Haar, S.; Puente Cruz, I.

1979-07-01T23:59:59.000Z

313

Fault Detection, Location, Isolation and Reconnection in ...  

A University of Colorado research team led by Jae-Do Park has developed a fault detection, location and isolation scheme for a low-voltage DC-bus microgrid system, ...

314

Fault tolerance for holonomic quantum computation  

E-Print Network (OSTI)

We review an approach to fault-tolerant holonomic quantum computation on stabilizer codes. We explain its workings as based on adiabatic dragging of the subsystem containing the logical information around suitable loops along which the information remains protected.

Ognyan Oreshkov; Todd A. Brun; Daniel A. Lidar

2013-12-01T23:59:59.000Z

315

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

SciTech Connect

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.

Potirakis, S. M. [Department of Electronics, Technological Education Institute (TEI) of Piraeus, 250 Thivon and P. Ralli, Aigaleo, Athens GR-12244 (Greece)] [Department of Electronics, Technological Education Institute (TEI) of Piraeus, 250 Thivon and P. Ralli, Aigaleo, Athens GR-12244 (Greece); Karadimitrakis, A. [Department of Physics, Section of Electronics, Computers, Telecommunications and Control, University of Athens, Panepistimiopolis, Zografos, Athens GR-15784 (Greece)] [Department of Physics, Section of Electronics, Computers, Telecommunications and Control, University of Athens, Panepistimiopolis, Zografos, Athens GR-15784 (Greece); Eftaxias, K. [Department of Physics, Section of Solid State Physics, University of Athens, Panepistimiopolis, Zografos, Athens GR-15784 (Greece)] [Department of Physics, Section of Solid State Physics, University of Athens, Panepistimiopolis, Zografos, Athens GR-15784 (Greece)

2013-06-15T23:59:59.000Z

316

Vaporizing Flow in Hot Fractures: Observations from Laboratory Experiments  

DOE Green Energy (OSTI)

Understanding water seepage in hot fractured rock is important in a number of fields including geothermal energy recovery and nuclear waste disposal. Heat-generating high-level nuclear waste packages which will be emplaced in the partially saturated fractured tuffs at the potential high-level nuclear waste repository at Yucca Mountain, Nevada, if it becomes a high-level nuclear waste repository, will cause significant impacts on moisture distribution and migration. Liquid water, which occupies anywhere from 30 to 100% of the porespace, will be vaporized as the temperature reaches the boiling temperature. Flowing primarily in fractures, the vapor will condense where it encounters cooler rock, generating mobile water. This water will flow under gravitational and capillary forces and may flow back to the vicinity of the emplaced waste where it may partially escape vaporization. Water flowing down (sub-) vertical fractures may migrate considerable distances through fractured rock that is at above-boiling temperatures; thus, flowing condensate may contact waste packages, and provide a pathway for the transport of water-soluble radionuclides downward to the saturated zone. Thermally-driven flow processes induced by repository heat may be as important or even more important for repository performance than natural infiltration. For a nominal thermal loading of 57 kW/acre, vaporization may generate an average equivalent percolation flux from condensate of 23.1 mm/yr over 1,000 years, and 5.2 mm/yr over 10,000 years. These numbers are comparable to or larger than current estimates of net infiltration at Yucca Mountain. This condensate, which is generated in the immediate vicinity (meters) of the waste packages, will likely have a larger impact on waste package and repository performance than a similar amount of water introduced at the land surface.

Kneafsey, T.; Pruess, K.

1998-12-01T23:59:59.000Z

317

Building Technologies Office: Climate Zones  

NLE Websites -- All DOE Office Websites (Extended Search)

Climate Zones to Climate Zones to someone by E-mail Share Building Technologies Office: Climate Zones on Facebook Tweet about Building Technologies Office: Climate Zones on Twitter Bookmark Building Technologies Office: Climate Zones on Google Bookmark Building Technologies Office: Climate Zones on Delicious Rank Building Technologies Office: Climate Zones on Digg Find More places to share Building Technologies Office: Climate Zones on AddThis.com... About Take Action to Save Energy Partner With DOE Activities Solar Decathlon Building America Research Innovations Research Tools Building Science Education Climate-Specific Guidance Solution Center Partnerships Meetings Publications Home Energy Score Home Performance with ENERGY STAR Better Buildings Neighborhood Program Challenge Home Guidelines for Home Energy Professionals

318

Rift Zone | Open Energy Information  

Open Energy Info (EERE)

Rift Zone Rift Zone Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Print PDF Rift Zone Dictionary.png Rift Zone: A divergent plate boundary within a continent Other definitions:Wikipedia Reegle Tectonic Settings List of tectonic settings known to host modern geothermal systems: Extensional Tectonics Subduction Zone Rift Zone Hot Spot Non-Tectonic Strike-Slip The Rio Grande Rift exemplifies rift zone tectonics - increased volcanic activity and the formation of graben structures (reference: science-art.com) Rift valleys occur at divergent plate boundaries, resulting in large graben structures and increased volcanism. The East African Rift is an example of a continental rift zone with increased volcanism, while the Atlantic's spreading Mid-Ocean Ridge is host to an enormous amount of geothermal

319

The Enterprise Zone (Rhode Island)  

Energy.gov (U.S. Department of Energy (DOE))

The Enterprise Zone offers tax incentives to business expanding their workforce by 5% at facilities in designated enterprise zones. The tax credit is equal to 50% of the annual wages paid to a new...

320

Radiant zone heated particulate filter  

DOE Patents (OSTI)

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.

Gonze, Eugene V [Pinckney, MI

2011-12-27T23:59:59.000Z

Note: This page contains sample records for the topic "fracture zones faults" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


321

Regional Analysis and Characterization of Fractured Aquifers in the Virginia Blue Ridge and Piedmont Provinces  

SciTech Connect

Areas related to low-temperature geothermal applications include the recognition of and exploration for deep fracture permeability in crystalline rocks. It is well known that the best currently available downhole techniques to identify the locations of fracture zones in crystalline rocks depend upon the measurement of some thermal parameter such as temperature or heat flow. The temperature-depth profiles and their derivatives provide a direct indication of those fracture zones that conduct water. The exploration for new groundwater resources is considered by many to be the new frontier in the general field of hydrology. The availability of adequate groundwater resources in fractured rocks is a major concern in many areas of the eastern US as well as in the other parts of the world. A geothermal database can therefore 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 augment our web site (http://rglsun1.geol.vt.edu) with new geothermal data as the data become available, and to advertise the increasing residential uses of geothermal energy in the eastern US. This work was originally titled ''Archival of Geothermal Exploration Data,'' and was initiated to make available to the public the extensive geothermal database for the southeastern US. These data include plots of temperature and geothermal gradient logs, scans of 7.5-min quadrangles where appropriate, and annotated location maps.

Costain, J.K.

2000-07-25T23:59:59.000Z

322

A physically based numerical approach for modeling fracture-matrix interaction in fractured reservoirs  

E-Print Network (OSTI)

modeling fluid and heat flow in fractured porous media, Soc.flow through unsaturated fractured porous media, Proceedings of the Second International Symposium on Dynamics of Fluids

Wu, Yu-Shu; Pruess, Karsten

2004-01-01T23:59:59.000Z

323

A Physically Based Approach for Modeling Multiphase Fracture-Matrix Interaction in Fractured Porous Media  

E-Print Network (OSTI)

modeling fluid and heat flow in fractured porous media, Soc.flow through unsaturated fractured porous media, Proceedings of the Second International Symposium on Dynamics of Fluids

Wu, Yu-Shu; Pan, Lehua; Pruess, Karsten

2004-01-01T23:59:59.000Z

324

The Essential Work of Fracture Method Applied to Mode II Interlaminar Fracture in Fiber Reinforced Polymers.  

E-Print Network (OSTI)

??This thesis presents a new method for determining mode II interlaminar fracture toughness in fiber reinforced polymers (FRP) using the essential work of fracture (EWF)… (more)

McKinney, Scott D

2013-01-01T23:59:59.000Z

325

Hydraulic fracture optimization using hydraulic fracture and reservoir modeling in the Piceance Basin, Colorado.  

E-Print Network (OSTI)

??Hydraulic fracturing is an important stimulation method for producing unconventional gas reserves. Natural fractures are present in many low-permeability gas environments and often provide important… (more)

Reynolds, Harris Allen

2012-01-01T23:59:59.000Z

326

A Site-Scale Model For Fluid And Heat Flow In The Unsaturated Zone Of Yucca  

Open Energy Info (EERE)

Site-Scale Model For Fluid And Heat Flow In The Unsaturated Zone Of Yucca Site-Scale Model For Fluid And Heat Flow In The Unsaturated Zone Of Yucca Mountain, Nevada Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Journal Article: A Site-Scale Model For Fluid And Heat Flow In The Unsaturated Zone Of Yucca Mountain, Nevada Details Activities (0) Areas (0) Regions (0) Abstract: A three-dimensional unsaturated-zone numerical model has been developed to simulate flow and distribution of moisture, gas and heat at Yucca Mountain, Nevada, a potential repository site for high-level radioactive waste. The model takes into account the simultaneous flow dynamics of liquid water, vapor, air and heat in the highly heterogeneous, fractured porous rock in the unsaturated zone (UZ). This model is intended for use in the prediction of the current and future conditions in the UZ so

327

Characterization of Fracture Patterns in the Geysers Geothermal Reservoir by Shear-wave Splitting  

DOE Green Energy (OSTI)

The authors have analyzed the splitting of shear waves from microearthquakes recorded by a 16-station three-component seismic network at the Northwest Geysers geothermal field, Geysers, California, to determine the preferred orientation of subsurface fractures and cracks. Average polarization crack directions with standard deviation were computed for each station. 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 steam field are predominantly in the N10{degree}E to N50{degree}E direction, consistent with expected fracture directions in a pull-apart basin created by sub-parallel right-lateral strike-slip faults related to the San Andreas fault system. Time delays range from 15--60 ms, similar to the time delays from previous studies at geothermal reservoirs. They have detected a significant increase in time delays between 1988 and 1994, which they attribute to widening of the cracks or filling of the cracks with fluid. Increase in production activities during this time also could have influenced this widening.

D. Erten; J. A. Rial

1999-09-15T23:59:59.000Z

328

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  

Science Conference Proceedings (OSTI)

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.

G. Michael Grammer

2005-11-09T23:59:59.000Z

329

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

SciTech Connect

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.

NONE

1997-12-31T23:59:59.000Z

330

CO2 Emissions - Panama Canal Zone  

NLE Websites -- All DOE Office Websites (Extended Search)

Panama Canal Zone Graphics CO2 Emissions from Panama Canal Zone Data graphic Data CO2 Emissions from Panama Canal Zone...

331

Transition Zone Geothermal Region | Open Energy Information  

Open Energy Info (EERE)

Transition Zone Geothermal Region (Redirected from Transition Zone) Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Transition Zone Geothermal Region edit Details...

332

A Closer Look at Salt, Faults, and Gas in the Northwestern Gulf of Mexico with 2-D Multichannel Seismic Data  

E-Print Network (OSTI)

The sedimentary wedge of the northern Gulf of Mexico is extensively deformed and faulted by salt tectonics. Industry 2-D multichannel seismic data covering a large area (33,800 km2) of the lower Texas continental slope [96 degrees 40'- 93 degrees 40'W; 27 degrees 10N - 26 degrees N] were examined to evaluate the interplay of salt, faults and gas. Seismic interpretation revealed the study area has two different styles of faulting and two different types of salt bodies that vary east to west. The eastern region of the study area has a thin sedimentary section and a massive, nearly continuous salt sheet characterized by minibasins and local salt highs. Faulting in this area appears to be the result of salt tectonism. The western region of the study area has a thick sedimentary wedge, and a few isolated salt diapirs. Long, linear faults are parallel to slope and imply some degree of gravitation sliding. The difference in faulting styles and salt bodies can be attributed to different depositional environments, different styles and amounts of sediment loading and different amounts of salt initially deposited. While there is a widespread occurrence of gas throughout the study area, little evidence of continuous bottom simulating reflectors (BSRs), a widely accepted geophysical indicator of gas hydrate, has been found. The gas hydrate stability zone (GHSZ) was modeled to provide information on the thickness and variability of the stability zone, and provide a baseline in a search for BSRs. The dataset was analyzed for multiple seismic expressions of BSRs, however only a few small and isolated examples were found. Potential fluid escape structures were seen in the seismic data. Despite the great number of potential features found in the seismic data only seven active seeps were found in a seep study by I. R. MacDonald. Seeps were seen in far less abundance than the number of seeps found offshore Louisiana. This may imply a lack of source offshore Texas.

Nemazi, Leslie A.

2010-05-01T23:59:59.000Z

333

Nonisothermal injection tests in fractured reservoirs  

DOE Green Energy (OSTI)

The paper extends the analysis of nonisothermal pressure transient data to fractured reservoirs. Two cases are considered: reservoirs with predominantly horzontal fractures and reservoirs with predominantly vertical fractures. Effects of conductive heat transfer between the fractures and the rock matrix are modeled, and the resulting pressure transients evaluated. Thermal conduction tends to retard the movement of the thermal front in the fractures, which significantly affects the pressure transient data. The purpose of the numerical simulation studies is to provide methods for analyzing nonisothermal injection/falloff data for fractured reservoirs.

Cox, B.L.; Bodvarsson, G.S.

1985-01-01T23:59:59.000Z

334

Monitoring hydraulic fracture growth: Laboratory experiments  

Science Conference Proceedings (OSTI)

The authors carry out small-scale hydraulic fracture experiments to investigate the physics of hydraulic fracturing. The laboratory experiments are combined with time-lapse ultrasonic measurements with active sources using both compressional and shear-wave transducers. For the time-lapse measurements they focus on ultrasonic measurement changes during fracture growth. As a consequence they can detect the hydraulic fracture and characterize its shape and geometry during growth. Hence, this paper deals with fracture characterization using time-lapse acoustic data. Hydraulic fracturing is used in the oil and gas industry to stimulate reservoir production.

Groenenboom, J.; Dam, D.B. van

2000-04-01T23:59:59.000Z

335

Measuring and Modeling Fault Density for Plume-Fault Encounter Probability Estimation  

Science Conference Proceedings (OSTI)

Emission of carbon dioxide from fossil-fueled power generation stations contributes to global climate change. Storage of this carbon dioxide within the pores of geologic strata (geologic carbon storage) is one approach to mitigating the climate change that would otherwise occur. The large storage volume needed for this mitigation requires injection into brine-filled pore space in reservoir strata overlain by cap rocks. One of the main concerns of storage in such rocks is leakage via faults. In the early stages of site selection, site-specific fault coverages are often not available. This necessitates a method for using available fault data to develop an estimate of the likelihood of injected carbon dioxide encountering and migrating up a fault, primarily due to buoyancy. Fault population statistics provide one of the main inputs to calculate the encounter probability. Previous fault population statistics work is shown to be applicable to areal fault density statistics. This result is applied to a case study in the southern portion of the San Joaquin Basin with the result that the probability of a carbon dioxide plume from a previously planned injection had a 3% chance of encountering a fully seal offsetting fault.

Jordan, P.D.; Oldenburg, C.M.; Nicot, J.-P.

2011-05-15T23:59:59.000Z

336

Liquid zone seal  

DOE Patents (OSTI)

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.

Klebanoff, Leonard E. (Dublin, CA)

2001-01-01T23:59:59.000Z

337

A fault location approach for fuzzy fault section estimation on radial distribution feeders  

E-Print Network (OSTI)

Locating the faulted section of a distribution system is a difficult task because of lack of accurate system models and the presence of uncertainty in the data used for estimating the fault section. Many of the methods used to account for the uncertainty use fuzzy logic techniques to estimate bounds of possibility of the input data and calculated quantities, or probabilistic modeling of the input data to estimate the likelihood of the location of the fault on a particular section of the feeder. Heuristic knowledge of control center dispatchers has also been used for uncertainty management. This thesis presents the design and implementation of a phase selector algorithm and a fault distance algorithm for use in an automated modular scheme for fault section estimation on radial distribution systems. These two algorithms will be executed in combination with two other fault location algorithms. The scheme is executed using the data record of an abnormal event in a three-stage scheme. The phase selector algorithm was used to obtain event-phase possibility values representing the possibility of involvement of each of the phases and the neutral in an event. A section-event possibility value that indicated the possibility that a section of the feeder was involved in the fault was evaluated using the event-phase possibility values and line section phase topology information. The fault distance algorithm was used to eliminate sections of the feeder that were not likely to be possible faulted section candidates by assuming a bolted fault and estimating its location. Each line section was assigned a fault possibility value of zero or one according to its location relative to the location of the fault. The phase selector algorithm was tested using real data measured at feeder substations and the fault distance algorithm was tested using data obtained by staging faults on a model of an overhead feeder using EMTP/ATP simulation. The results obtained from the tests were promising. A simple illustration of the combination of the results of the two algorithms is given. The result of this combination shows the potential of the simultaneous use of the two algorithms.

Andoh, Kwame Sarpong

2000-01-01T23:59:59.000Z

338

Holocene surface faulting along the west flank of the Santa Rosa Range (Nevada-Oregon) and the possible northern extension of the Central Nevada Seismic Belt  

Science Conference Proceedings (OSTI)

The 130 km long Santa Rose Range fault system extends northward from a point about 70 km north of the 1915 Pleasant Valley earthquake fault ruptures to Blue Mountain Pass, Oregon. The authors have examined 1:12,000 low-sun-angle aerial photographs and conducted surveys of scarp morphology to investigate the neotectonic evolution and paleoseismicity of this possible northern extension of the Central Nevada Seismic Belt. Two adjoining segments of the fault zone are separated by a right step in the range-front and apparent absence of Holocene scarps. Each segment records evidence of a Holocene faulting event. The southern 31 km segment between Frey Ranch and the Willow Creek fan shows both small scarps (Valley and larger scarps which oversteepen the base of the adjacent range-front to slopes of 20[degree] to 24[degree]. The northern 42 km segment between Flat Creek and Oregon Canyon Creek shows a recent offset which rejuvenates older (pre-Lahontan) fault scarps and also cuts Holocene terraces along the base of the piedmont pediment. Based on preliminary morphometric data, the maximum vertical displacement (3--4 m) and age of the faulting (early Holocene) are similar in both segments but it is not known whether both segments ruptured contemporaneously. Except for the lack of large historical surface faulting the main neotectonic and geomorphic features of the Santa Rose Range fault zone are similar to that of the Dixie Valley and Pleasant Valley regions of the Central Nevada Seismic Belt. Hence, the occurrence of a large earthquake rupture along this range-front in the near future should not be viewed as a surprise.

Michetti, A.M. (CNR/GNDT, Rome (Italy) Univ. of Nevada, Reno, NV (United States). Center for Neotectonic Studies); Wesnousky, S.G. (Univ. of Nevada, Reno, NV (United States). Center for Neotectonic Studies)

1993-04-01T23:59:59.000Z

339

Fault Locating, Prediction and Protection (FLPPS)  

Science Conference Proceedings (OSTI)

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, hi

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

2010-09-30T23:59:59.000Z

340

Fast Fault Recovery in Switched Networks for Carrying IP Telephony Traffic.  

E-Print Network (OSTI)

?? One of the most parts of VOIP management is fault management and, in having a good fault management, finding good mechanisms to detect faults… (more)

Eisazadeh, Ali Akbar

2010-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "fracture zones faults" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


341

Hydraulic Fracturing | Open Energy Information  

Open Energy Info (EERE)

Hydraulic Fracturing Hydraulic Fracturing Jump to: navigation, search More info on OpenEI Oil and Gas Gateway Federal Environmental Statues Federal Oil and Gas Statutes Oil and Gas Companies United States Oil and Gas Boards International Oil and Gas Boards Other Information Fracking Regulations by State Wells by State Fracking Chemicals Groundwater Protection Related Reports A Perspective on Health and Natural Gas Operations: A Report for Denton City Council Just the Fracking Facts The Politics of 'Fracking': Regulating Natural Gas Drilling Practices in Colorado and Texas Addressing the Environmental Risks from Shale Gas Development Water Management Technologies Used by Marcellus Shale Gas Producers Methane contamination of drinking wateraccompanying gas-well drilling and hydraulic fracturing

342

Method for directional hydraulic fracturing  

DOE Patents (OSTI)

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.

Swanson, David E. (West St. Paul, MN); Daly, Daniel W. (Crystal, MN)

1994-01-01T23:59:59.000Z

343

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

Science Conference Proceedings (OSTI)

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.

James R. Wood; William B. Harrison

2002-12-01T23:59:59.000Z

344

ADVANCED TECHNOLOGY FOR PREDICTING THE FLUID FLOW ATTRIBUTES OF NATURALLY FRACTURED RESERVOIRS FROM QUANTITATIVE GEOLOGIC DATA AND MODELING  

Science Conference Proceedings (OSTI)

This report summarizes the work carried out during the period of September 29, 2000 to September 28, 2001 under DOE Research Contract No. DE-FC26-00BC15308. Our goal is to establish an integrated methodology of fractured reservoir characterization and show how that can be incorporated into fluid flow simulation. We have made progress in the characterization of mineral infilling of natural fractures. The main advancement in this regard was to recognize the strong interplay between diagenetic and mechanical processes. We accomplished several firsts in documenting and quantifying these processes, including documenting the range of emergent threshold in several formations and quantifying the internal structures of crack-seal bridges in fractures. These results will be the basis for an appreciation of fracture opening and filling rates that go well beyond our original goals. Looking at geochemical modeling of fracture infilling, our theoretical analysis addressed the problem of calcite precipitation in a fracture. We have built a model for the deposition of calcite within a fracture. The diagenetic processes of dissolution and partial cementation are key controls on the creation and distribution of natural fractures within hydrocarbon reservoirs. Even with extensive data collection, fracture permeability still creates uncertainty in reservoir description and the prediction of well performance. Data on the timing and stages of diagenetic events can provide explanation as to why, when and where natural fractures will be open and permeable. We have been pursuing the fracture mechanics testing of a wide range of rocks, particularly sandstone using a key rock property test that has hitherto not been widely applied to sedimentary rocks. A major accomplishment in this first year has been to identify sample suites available in the core repository at the University of Texas that represent a wide range of diagenetic alteration and to begin to test these samples. The basis for the fluid flow simulations to be carried out in this part of the project is the adequate spatial characterization of fracture networks. Our initial focus has been on the tendency of fracture sets to cluster into highly fracture zones that are often widely separated. Our preliminary modeling work shows the extent of this clustering to be controlled by the subcritical fracture index of the material. With continued progress, we move toward an integrated fracture characterization methodology that will ultimately be applied through detailed reservoir simulation.

Jon E. Olson; Larry W. Lake; Steve E. Laubach

2003-04-01T23:59:59.000Z

345

Lithology, fault displacement, and origin of secondary calcium carbonate and opaline silica at Trenches 14 and 14D on the Bow Ridge Fault at Exile Hill, Nye County, Nevada  

SciTech Connect

Yucca Mountain, a proposed site for a high-level nuclear-waste repository, is located in southern Nevada, 20 km east of Beatty, and adjacent to the southwest comer of the Nevada Test Site (NTS) (fig. 1). Yucca Mountain is located within the Basin and Range province of the western United States. The climate is semiarid, and the flora is transitional between that of the Mojave Desert to the south and the Great Basin Desert to the north. As part of the evaluation, hydrologic conditions, especially water levels, of Yucca Mountain and vicinity during the Quaternary, and especially the past 20,000 years, are being characterized. In 1982, the US Geological Survey, in cooperation with the US Department of Energy (under interagency agreement DE-A104-78ET44802), excavated twenty-six bulldozer and backhoe trenches in the Yucca Mountain region to evaluate the nature and frequency of Quaternary faulting (Swadley and others, 1984). The trenches were oriented perpendicular to traces of suspected Quaternary faults and across projections of known bedrock faults into Quaternary deposits. Trench 14 exposes the Bow Ridge Fault on the west side of Exile Hill. Although the original purpose of the excavation of trench 14 was to evaluate the nature and frequency of Quaternary faulting on the Bow Ridge Fault, concern arose as to whether or not the nearly vertical calcium carbonate (the term ``carbonate`` in this study refers to calcium carbonate) and opaline silica veins in the fault zone were deposited by ascending waters (ground water). These veins resemble in gross morphology veins commonly formed by hydrothermal processes.

Taylor, E.M.; Huckins, H.E.

1995-02-01T23:59:59.000Z

346

Modeling flow and transport in unsaturated fractured rock: An evaluation of the continuum approach  

Science Conference Proceedings (OSTI)

Because the continuum approach is relatively simple and straightforward to implement, it has been commonly used in modeling flow and transport in unsaturated fractured rock. However, the usefulness of this approach can be questioned in terms of its adequacy for representing fingering flow and transport in unsaturated fractured rock. The continuum approach thus needs to be evaluated carefully by comparing simulation results with field observations directly related to unsaturated flow and transport processes. This paper reports on such an evaluation, based on a combination of model calibration and prediction, using data from an infiltration test carried out in a densely fractured rock within the unsaturated zone of Yucca Mountain, Nevada. Comparisons between experimental and modeling results show that the continuum approach may be able to capture important features of flow and transport processes observed from the test. The modeling results also show that matrix diffusion may have a significant effect on the overall transport behavior in unsaturated fractured rocks, which can be used to estimate effective fracture-matrix interface areas based on tracer transport data. While more theoretical, numerical, and experimental studies are needed to provide a conclusive evaluation, this study suggests that the continuum approach is useful for modeling flow and transport in unsaturated, densely fractured rock.

Liu, Hui-Hai; Haukwa, Charles B.; Ahlers, C. Fredrik; Bodvarsson, Gudmundur S.; Flint, Alan L.; Guertal, William B.

2002-09-01T23:59:59.000Z

347

Climate Zone 5C | Open Energy Information  

Open Energy Info (EERE)

Climate Zone 5C Jump to: navigation, search A type of climate defined in the ASHRAE 169-2006 standard consisting of Climate Zone Number 5 and Climate Zone Subtype C. Climate Zone...

348

History and Results of Surface Exploration in the Kilauea East Rift Zone |  

Open Energy Info (EERE)

History and Results of Surface Exploration in the Kilauea East Rift Zone History and Results of Surface Exploration in the Kilauea East Rift Zone Jump to: navigation, search OpenEI Reference LibraryAdd to library Conference Paper: History and Results of Surface Exploration in the Kilauea East Rift Zone Abstract Government-funded surveys of the Kilauea East Rift Zone have resulted in a wealth of geophysical and geochemical data from an active volcanic area. All data are clearly of academic interest; Hawaii was used as a testing ground for various geophysical methods in the early days of geothermal exploration. Some surveys, such as gravity and magnetic, are useful a regional perspective for determining broad structural trends and grossly identifying magmatic intrusions. Seismic data are currently being used for a more sitespecific purpose: to determine fault locations and geometries.

349

Acoustic Character Of Hydraulic Fractures In Granite  

E-Print Network (OSTI)

Hydraulic fractures in homogeneous granitic rocks were logged with conventional acoustic-transit-time, acoustic-waveform, and acoustic-televiewer logging systems. Fractured intervals ranged in depth from 45 to 570m. and ...

Paillet, Frederick I.

1983-01-01T23:59:59.000Z

350

Effects of dry fractures on matrix diffusion in unsaturated fractured rocks  

E-Print Network (OSTI)

Symposium on Multiphase Transport in Porous Media, ASMEmultiphase heat and mass flow in unsaturated fractured porous

Seol, Yongkoo; Liu, Hui Hai; Bodvarsson, Gudmundur S.

2002-01-01T23:59:59.000Z

351

Dissipative particle dynamics simulation of fluid motion through an unsaturated fracture and fracture junction  

Science Conference Proceedings (OSTI)

Multiphase fluid motion in unsaturated fractures and fracture networks involves complicated fluid dynamics, which is difficult to model using grid-based continuum methods. In this paper, the application of dissipative particle dynamics (DPD), a relatively ... Keywords: Dissipative particle dynamics (DPD), Fracture, Fracture flow, Smoothed particle hydrodynamics (SPH), Weight functions

Moubin Liu; Paul Meakin; Hai Huang

2007-03-01T23:59:59.000Z

352

Summary of Linear Elastic Fracture Mechanics Concepts  

Science Conference Proceedings (OSTI)

...in this Volume."Stress Intensity Factors"A brief summary of linear elastic fracture mechanics (LEFM) concepts

353

Development of a fixation device for robot assisted fracture reduction of femoral shaft fractures: A biomechanical study  

Science Conference Proceedings (OSTI)

Robot assisted fracture reduction of femoral shaft fractures provides precise alignment while reducing the amount of intraoperative imaging. The connection between the robot and the fracture fragment should allow conventional intramedullary nailing, ... Keywords: Robot, femur shaft, fracture reduction, interface

T. S. Weber-Spickschen; M. Oszwald; R. Westphal; C. Krettek; F. Wahl; T. Gosling

2010-08-01T23:59:59.000Z

354

Optimizing fracture stimulation using treatment-well tiltmeters and integrated fracture modeling  

Science Conference Proceedings (OSTI)

This paper covers the optimization of hydraulic fracture treatments in a new coalbed methane (CBM) reservoir in Wyoming. A multiwell pilot project was conducted in the Copper Ridge (CR) field to assess future development potential. Hydraulic fracture mapping was successfully performed with treatment-well tiltmeters on six wells including the first-ever used on propped treatments. The mapped fracture height was then used to calibrate the fracture model, perform on-site fracture-design changes, and optimize future fracture treatments. This paper shows how early use of fracture diagnostics can assist in the development of a new reservoir.

Mayerhofer, M.; Stutz, L.; Davis, E.; Wolhart, S. [Pinnacle Technology Houston, Houston, TX (United States)

2006-05-15T23:59:59.000Z

355

VCSEL fault location apparatus and method  

DOE Patents (OSTI)

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.

Keeler, Gordon A. (Albuquerque, NM); Serkland, Darwin K. (Albuquerque, NM)

2007-05-15T23:59:59.000Z

356

Fractured shale reservoirs: Towards a realistic model  

Science Conference Proceedings (OSTI)

Fractured shale reservoirs are fundamentally unconventional, which is to say that their behavior is qualitatively different from reservoirs characterized by intergranular pore space. Attempts to analyze fractured shale reservoirs are essentially misleading. Reliance on such models can have only negative results for fractured shale oil and gas exploration and development. A realistic model of fractured shale reservoirs begins with the history of the shale as a hydrocarbon source rock. Minimum levels of both kerogen concentration and thermal maturity are required for effective hydrocarbon generation. Hydrocarbon generation results in overpressuring of the shale. At some critical level of repressuring, the shale fractures in the ambient stress field. This primary natural fracture system is fundamental to the future behavior of the fractured shale gas reservoir. The fractures facilitate primary migration of oil and gas out of the shale and into the basin. In this process, all connate water is expelled, leaving the fractured shale oil-wet and saturated with oil and gas. What fluids are eventually produced from the fractured shale depends on the consequent structural and geochemical history. As long as the shale remains hot, oil production may be obtained. (e.g. Bakken Shale, Green River Shale). If the shale is significantly cooled, mainly gas will be produced (e.g. Antrim Shale, Ohio Shale, New Albany Shale). Where secondary natural fracture systems are developed and connect the shale to aquifers or to surface recharge, the fractured shale will also produce water (e.g. Antrim Shale, Indiana New Albany Shale).

Hamilton-Smith, T. [Applied Earth Science, Lexington, KY (United States)

1996-09-01T23:59:59.000Z

357

Breathing zone air sampler  

DOE Patents (OSTI)

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.

Tobin, John (Bethel Park, PA)

1989-01-01T23:59:59.000Z

358

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

SciTech Connect

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.

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

2008-09-30T23:59:59.000Z

359

Size effect and fracture characteristics of composite laminates  

Science Conference Proceedings (OSTI)

Measurements of the size effect on the nominal strength of notched specimens of fiber composite laminates are reported. Tests were conducted on graphite/epoxy crossply and quasi-isotropic laminates. The specimens were rectangular strips of widths 6.4, 12.7, 25.4 and 50.8 mm (0.25, 0.50, 1.00 and 2.00 in.) geometrically similar in two dimensions. The gage lengths were 25, 51, 102 and 203 mm (1.0, 2.0, 4.0 and 8.0 in.). One set of specimens had double-edge notches and a [0/92{sub 2}]{sub s} crossply layup, and another set had a single-sided edge notch and a [0/{+-}45/90]{sub s} quasi-isotropic layup. It has been found that there is a significant size effect on the nominal strength. It approximately agrees with the size effect law proposed by Bazant, according to which the curve of the logarithm of the nominal strength versus the logarithm of size represents a smooth transition from a horizontal asymptote, corresponding to the strength criterion (plastic limit analysis), to an inclined asymptote of {minus}0.5 slope, corresponding to linear elastic fracture mechanics. Optimum fits of the test results to identify the material fracture characteristics, particularly the fracture energy and the effective length of the fracture process zone. Finally, the R-curves are also identified on the basis of the maximum load data. The results show that in design situations with notches or large initial traction-free cracks the size effect on the nominal strength of fiber composite laminates must be taken into account.

Bazant, Z.P.; Daniel, I.M.; Li, Z. [Northwestern Univ., Evanston, IL (United States)

1996-07-01T23:59:59.000Z

360

Western Renewable Energy Zones (Presentation)  

DOE Green Energy (OSTI)

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

Hein, J.

2011-06-01T23:59:59.000Z

Note: This page contains sample records for the topic "fracture zones faults" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


361

DOE Solar Decathlon: Comfort Zone  

NLE Websites -- All DOE Office Websites (Extended Search)

Decathlon Comfort Zone Contest, teams design their houses to keep temperature and humidity steady, uniform, and comfortable. Full points are awarded for maintaining narrow...

362

Interfacial Transition Zone Bibliography Database  

Science Conference Proceedings (OSTI)

... Saito, M., and Kawamura, M., Effect of Fly Ash and Slag on the Interfacial Zone Between Cement and Aggregate , in ACI SP 114: Fly Ash, Silica ...

2013-05-14T23:59:59.000Z

363

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

E-Print Network (OSTI)

thus far, but to conduct investigation of possible abutmentNUMO when it conducts preliminary investigations at yet-to-Design and plan work Conduct surface investigation activity

Karasaki, Kenzi

2010-01-01T23:59:59.000Z

364

Development of a Hydrologic Characterization Technology for Fault Zones Phase II 2nd Report  

E-Print Network (OSTI)

sample, (b) Dieselstandard (c) motor oil, and (d) crude oilc) and (d) are the diesel, motor oil, and crude oil standardto be a mixture of diesel and motor oil. One alternative

Karasaki, Kenzi

2013-01-01T23:59:59.000Z

365

Development of a Hydrologic Characterization Technology for Fault Zones Phase II 2nd Report  

E-Print Network (OSTI)

deposition of the Monterey Formation and related siliceousJ.C.Jr, eds.The Monterey Formation and related siliceousin the Miocene Monterey Formation, Santa Barbara coastal

Karasaki, Kenzi

2013-01-01T23:59:59.000Z

366

Development of a Hydrologic Characterization Technology for Fault Zones Phase II 2nd Report  

E-Print Network (OSTI)

2-2 Original electrical resistivity survey interpretationnatural gamma, electrical resistivity, SP, televiewer,2-1 2.2 Electrical Resistivity Survey (ER-

Karasaki, Kenzi

2013-01-01T23:59:59.000Z

367

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

E-Print Network (OSTI)

1, 2 and 3 for electrical resistivity and seismic reflection89 Figure 3-36. Electrical resistivity profiles for Line 1(40. Superimposed plot of electrical resistivity and seismic

Karasaki, Kenzi

2010-01-01T23:59:59.000Z

368

Geometry of Cenozoic extensional faulting: Dixie Valley, Nevada | Open  

Open Energy Info (EERE)

Geometry of Cenozoic extensional faulting: Dixie Valley, Nevada Geometry of Cenozoic extensional faulting: Dixie Valley, Nevada Jump to: navigation, search OpenEI Reference LibraryAdd to library Journal Article: Geometry of Cenozoic extensional faulting: Dixie Valley, Nevada Abstract Precise definition of geometric relationships between individual basins and ranges may help to reveal the mechanical processes of Basin and Range Cenozoic extensional faulting at depth. Previous studies have attempted to identify simple horsts and grabens, tilted crustal blocks with planar faulting, or tilted crustal blocks with listric faulting in the shallow crust. Normal faults defining these crustal blocks may root (1) individually in the ductile lower crust, (2) in regional or local low-angle detachment faults, or (3) in igneous intrusions or decoupling surfaces

369

Synthesis and evaluation of fault-tolerant quantum computer architectures  

E-Print Network (OSTI)

Fault-tolerance is the cornerstone of practical, large-scale quantum computing, pushed into its prominent position with heroic theoretical efforts. The fault-tolerance threshold, which is the component failure probability ...

Cross, Andrew W. (Andrew William), 1979-

2005-01-01T23:59:59.000Z

370

Scalable Distributed Consensus to Support MPI Fault Tolerance  

Science Conference Proceedings (OSTI)

As system sizes increase, the amount of time in which an application can run without experiencing a failure decreases. Exascale applications will need to address fault tolerance. In order to support algorithm-based fault tolerance, communication libraries ...

Darius Buntinas

2012-05-01T23:59:59.000Z

371

Rough neural fault classification for hvdc power systems  

Science Conference Proceedings (OSTI)

This Ph.D. thesis proposes an approach to classify faults that commonly occur in a High Voltage Direct Current (HVDC) power system. These faults are distributed throughout the entire HVDC system. The most recently published techniques for power system ...

Liting Han

2008-01-01T23:59:59.000Z

372

High-level test synthesis for delay fault testability  

Science Conference Proceedings (OSTI)

A high-level test synthesis (HLTS) method targeted for delay fault testability is presented. The proposed method, when combined with hierarchical test pattern generation for embedded modules, guarantees 100% delay test coverage for detectable faults ...

Sying-Jyan Wang; Tung-Hua Yeh

2007-04-01T23:59:59.000Z

373

MODELING AND SIMULATION OF HVAC FAULTS IN ENERGYPLUS  

E-Print Network (OSTI)

sensor faults, Energy and Buildings. 42(4). April 2010.faults in buildings. Energy and Buildings. 42(1). Januaryon the DOE-2 model, Energy and Buildings. 21(2). 1994, Pages

Basarkar, Mangesh

2013-01-01T23:59:59.000Z

374

Stability of Distributed Algorithms in the Face of Incessant Faults  

Science Conference Proceedings (OSTI)

For large distributed systems built from inexpensive components, one expects to see incessant failures. This paper proposes two models for such faults and analyzes two well-known self-stabilizing algorithms under these fault models. For a small number ...

Robert E. Lee Deville; Sayan Mitra

2009-11-01T23:59:59.000Z

375

Design and Evaluation of Hybrid Fault-Detection Systems  

Science Conference Proceedings (OSTI)

As chip densities and clock rates increase, processors are becoming more susceptible to transient faults that can affect program correctness. Up to now, system designers have primarily considered hardware-only and software-only fault-detection mechanisms ...

George A. Reis; Jonathan Chang; Neil Vachharajani; Ram Rangan; David I. August; Shubhendu S. Mukherjee

2005-06-01T23:59:59.000Z

376

Two-person control administration: preventing administration faults through duplication  

Science Conference Proceedings (OSTI)

Modern computing systems are complex and difficult to administer, making them more prone to system administration faults. Faults can occur simply due to mistakes in the process of administering a complex system. These mistakes can make the system insecure ...

Shaya Potter; Steven M. Bellovin; Jason Nieh

2009-11-01T23:59:59.000Z

377

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

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

& Publications An Assessment of Fault Current Limiter Testing Requirements Superconductivity Program Overview Superconductivity for Electric Systems: 2008 Annual Peer Review...

378

EPRI Fault Current Management Guidebook, Sixth Edition (Maroon Book)  

Science Conference Proceedings (OSTI)

This document is an update of the document Fault Current Management Guidebook, Fifth Edition on fault current effects and management in transmission and distribution systems. This guide is intended to be a snapshot of available references, information, and literature on the effects of high fault current on a number of power system components and various available and emerging fault-current-limiting technologies.Results and FindingsDue to increased ...

2012-12-31T23:59:59.000Z

379

Underground Cable Fault Location Reference and Application Guide  

Science Conference Proceedings (OSTI)

This report summarizes underground cable fault location methods and details the application of the methods for transmission and distribution cable systems. It summarizes both terminal location and tracer location methods that can be applied to transmission and distribution cable systems. The report is an update to a summary of fault location methods. It provides practical technical material in the art and science of locating cable faults, including a description of common fault location instruments and p...

2011-12-23T23:59:59.000Z

380

Understanding Fault Characteristics of Inverter-Based Distributed Energy Resources  

SciTech Connect

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

Keller, J.; Kroposki, B.

2010-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "fracture zones faults" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


381

Method for enhancement of sequential hydraulic fracturing using control pulse fracturing  

Science Conference Proceedings (OSTI)

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.

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

1993-07-20T23:59:59.000Z

382

RESEARCH PROGRAM ON FRACTURED PETROLEUM RESERVOIRS  

Science Conference Proceedings (OSTI)

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.

Abbas Firoozabadi

2002-04-12T23:59:59.000Z

383

Interaction between Injection Points during Hydraulic Fracturing  

E-Print Network (OSTI)

We present a model of the hydraulic fracturing of heterogeneous poroelastic media. The formalism is an effective continuum model that captures the coupled dynamics of the fluid pressure and the fractured rock matrix and models both the tensile and shear failure of the rock. As an application of the formalism, we study the geomechanical stress interaction between two injection points during hydraulic fracturing (hydrofracking) and how this interaction influences the fracturing process. For injection points that are separated by less than a critical correlation length, we find that the fracturing process around each point is strongly correlated with the position of the neighboring point. The magnitude of the correlation length depends on the degree of heterogeneity of the rock and is on the order of 30-45 m for rocks with low permeabilities. In the strongly correlated regime, we predict a novel effective fracture-force that attracts the fractures toward the neighboring injection point.

Hals, Kjetil M D

2012-01-01T23:59:59.000Z

384

Microseismic Tracer Particles for Hydraulic Fracturing  

NLE Websites -- All DOE Office Websites (Extended Search)

Microseismic Tracer Particles for Hydraulic Fracturing Microseismic Tracer Particles for Hydraulic Fracturing Microseismic Tracer Particles for Hydraulic Fracturing Scientists at Los Alamos National Laboratory have developed a method by which microseismic events can be discriminated/detected that correspond to only the portion of the hydraulic fracture that contains the proppant material and can be expected to be conductive to the flow of oil and gas. July 3, 2013 Microseismic Tracer Particles for Hydraulic Fracturing Figure 1: A graph of ionic conductivity as a function of temperature for the anti-perovskite Li3OCl. Available for thumbnail of Feynman Center (505) 665-9090 Email Microseismic Tracer Particles for Hydraulic Fracturing Applications: Oil and gas production Geophysical exploration Benefits: Tracks the disposition of material in a hydraulic fracturing

385

Fault Diagnosis of Transformer Based on Probabilistic Neural Network  

Science Conference Proceedings (OSTI)

In order to improve the correct rate of transformer fault diagnosis based on three-ratio method of traditional dissolved gas analysis (DGA), a novel intelligent transformer fault diagnosis method based on both DGA and probabilistic neural network (PNN) ... Keywords: transformer fault diagnosis, probabilistic neural network (PNN), improved three-ratio method

Li Song; Li Xiu-ying; Wang Wen-xu

2011-03-01T23:59:59.000Z

386

New Burnside Anticline: part of Fluorspar area fault complex  

SciTech Connect

Field mapping in the Abbott Formation and examination of topographic lineaments in the Creal Springs, Stonefort, Eddyville, and Harrisburg Quadrangles (southeastern Illinois) reveal the New Burnside anticline and its northeastern extension, the Stonefort anticline to be a single, extensively faulted structure. Interpretation of this evidence also leads to the conclusion that this is a fault-block structure rather than an anticline. Trending notheast-southwest, the structure seems to be the northwesternmost extent of the Fluorspar Area fault complex. The authors found evidence for two episodes of faulting. The first involved northeast-trending, high-angle faults similar to those in the known Fluorspar complex to the southeast. Faults on the northeast (Stonefort antilcine) step down toward the center of the structure, forming a graben. Vertical movement also occurred to the southwest (New Burnside anticline), but the structure in this vicinity is a horst with some blocks tilted. As with other faults in the Fluorspar complex, horizontal slickensides are present locally. The second episode of movement occurred along northwest-southeast-trending strike-slip faults that offset the northeast-trending high-angle faults. This second phase of faulting may correspond with previously reported reactivation of northwest-trending faults elsewhere in the Fluorspar Area fault complex.

Jacobson, R.J.; Trask, C.B.

1983-09-01T23:59:59.000Z

387

Rigorous Development of Dependable Systems Using Fault Tolerance Views  

Science Conference Proceedings (OSTI)

This paper introduces the Mode and Fault Tolerance Views approach to stepwise rigorous development of critical systems. It supports systematic, structured and recursive modelling of system fault tolerance, including error detection, error recovery and ... Keywords: formal methods, Event-B, fault tolerance, modal systems, case study, AOCS

Ilya Lopatkin; Alexei Iliasov; Alexander Romanovsky

2011-11-01T23:59:59.000Z

388

Yet Another Fault Injection Technique : by Forward Body Biasing Injection  

E-Print Network (OSTI)

expensive fault injection tech- niques, like clock or voltage glitches, are well taken into accountYet Another Fault Injection Technique : by Forward Body Biasing Injection K. TOBICH1,2, P. MAURINE1 Injection, Electromag- netic Attacks, RSA, Chinese Remainder Theorem 1 Introduction Fault injection

389

Statistical estimation of multiple faults in aircraft gas turbine engines  

E-Print Network (OSTI)

415 Statistical estimation of multiple faults in aircraft gas turbine engines S Sarkar, C Rao of multiple faults in aircraft gas-turbine engines, based on a statistical pattern recognition tool called commercial aircraft engine. Keywords: aircraft propulsion, gas turbine engines, multiple fault estimation

Ray, Asok

390

Applications of fault detection methods to industrial processes  

Science Conference Proceedings (OSTI)

Components of industrial processes are often affected by un-permitted or un-expected deviations from normal operation behaviour. The fault detection task consists of determination of the fault present in a system and the time of detection. In addition ... Keywords: fault detection and diagnosis, industrial processes, residuals, symptoms

Ioana Fagarasan; S. S. T. Iliescu

2008-06-01T23:59:59.000Z

391

Collective operations in application-level fault-tolerant MPI  

Science Conference Proceedings (OSTI)

Fault-tolerance is becoming a critical issue on high-performance platforms. Checkpointing techniques make programs fault-tolerant by saving their state periodically and restoring this state after failure. System-level checkpointing saves the state ... Keywords: MPI, application-level checkpointing, collective communication, fault-tolerance, non-FIFO communication, scientific computing

Greg Bronevetsky; Daniel Marques; Keshav Pingali; Paul Stodghill

2003-06-01T23:59:59.000Z

392

Outlier Detection Rules for Fault Detection in Solar Photovoltaic Arrays  

E-Print Network (OSTI)

fault detection. Furthermore, the proposed models become more reliable as the number of PV measurements analysis specifically for PV installation. Several fault detection models and monitoring systems have been studied for PV systems [8]­[14]. PV monitoring and fault detection models based on energy yield and power

Lehman, Brad

393

A lightweight fault tolerance framework for Web services  

Science Conference Proceedings (OSTI)

In this paper, we present the design and implementation of a lightweight fault tolerance framework for Web services. With our framework, a Web service can be rendered fault tolerant by replicating it across several nodes. A consensus-based algorithm ... Keywords: Fault tolerance, Web services, distributed consensus, reliable messaging, replication

Wenbing Zhao; Honglei Zhang; Hua Chai

2009-08-01T23:59:59.000Z

394

Fault reconnaissance agent for sensor networks  

Science Conference Proceedings (OSTI)

One of the key prerequisite for a scalable, effective and efficient sensor network is the utilization of low-cost, low-overhead and high-resilient fault-inference techniques. To this end, we propose an intelligent agent system with a problem solving ... Keywords: Management, expectation maximization algorithm, intelligent agents, wireless sensor networks

Elhadi M. Shakshuki; Xinyu Xing; Tarek R. Sheltami

2010-08-01T23:59:59.000Z

395

Optimized Fault Location Final Project Report  

E-Print Network (OSTI)

excessive currents and voltages last long enough to cause equipment damage. CBs have the purpose to connect describes connectivity of the various components in the power system. In order to process retrieved fault, the system topology must be known. Beside the connectivity it is necessary to obtain information about

396

Hydrodynamics of a vertical hydraulic fracture  

DOE Green Energy (OSTI)

We have developed a numerical algorithm, HUBBERT, to simulate the hydrodynamics of a propagating vertical, rectangular fracture in an elastic porous medium. Based on the IFD method, this algorithm assumes fracture geometry to be prescribed. The breakdown and the creation of the incipient fracture is carried out according to the Hubbert-Willis theory. The propagation of the fracture is based on the criterion provided by Griffith, based on energy considerations. The deformation properties of the open fracture are based on simple elasticity solutions. The fracture is assumed to have an elliptical shape to a distance equal to the fracture height, beyond which the shape is assumed to be parallel plate. A consequence of Griffith's criterion is that the fracture must propagate in discrete steps. The parametric studies carried out suggest that for a clear understanding of the hydrodynamics of the hydraulic fracture many hitherto unrecognized parameters must be better understood. Among these parameters one might mention, efficiency, aperture of the newly formed fracture, stiffness of the newly formed fracture, relation between fracture aperture and permeability, and well bore compliance. The results of the studies indicate that the patterns of pressure transients and the magnitudes of fracture length appear to conform to field observations. In particular, the discrete nature of fracture propagation as well as the relevant time scales of interest inferred from the present work seem to be corroborated by seismic monitoring in the field. The results suggest that the estimation of least principal stress can be reliably made either with shut in data or with reinjection data provided that injection rates are very small.

Narasimhan, T.N.

1987-03-24T23:59:59.000Z

397

Zone refining of plutonium metal  

Science Conference Proceedings (OSTI)

The zone refining process was applied to Pu metal containing known amounts of impurities. Rod specimens of plutonium metal were melted into and contained in tantalum boats, each of which was passed horizontally through a three-turn, high-frequency coil in such a manner as to cause a narrow molten zone to pass through the Pu metal rod 10 times. The impurity elements Co, Cr, Fe, Ni, Np, U were found to move in the same direction as the molten zone as predicted by binary phase diagrams. The elements Al, Am, and Ga moved in the opposite direction of the molten zone as predicted by binary phase diagrams. As the impurity alloy was zone refined, {delta}-phase plutonium metal crystals were produced. The first few zone refining passes were more effective than each later pass because an oxide layer formed on the rod surface. There was no clear evidence of better impurity movement at the slower zone refining speed. Also, constant or variable coil power appeared to have no effect on impurity movement during a single run (10 passes). This experiment was the first step to developing a zone refining process for plutonium metal.

Blau, M.S.

1994-08-01T23:59:59.000Z

398

Evaluation and Effect of Fracturing Fluids on Fracture Conductivity in Tight Gas Reservoirs Using Dynamic Fracture Conductivity Test  

E-Print Network (OSTI)

Unconventional gas has become an important resource to help meet our future energy demands. Although plentiful, it is difficult to produce this resource, when locked in a massive sedimentary formation. Among all unconventional gas resources, tight gas sands represent a big fraction and are often characterized by very low porosity and permeability associated with their producing formations, resulting in extremely low production rate. The low flow properties and the recovery factors of these sands make necessary continuous efforts to reduce costs and improve efficiency in all aspects of drilling, completion and production techniques. Many of the recent improvements have been in well completions and hydraulic fracturing. Thus, the main goal of a hydraulic fracture is to create a long, highly conductive fracture to facilitate the gas flow from the reservoir to the wellbore to obtain commercial production rates. Fracture conductivity depends on several factors, such as like the damage created by the gel during the treatment and the gel clean-up after the treatment. This research is focused on predicting more accurately the fracture conductivity, the gel damage created in fractures, and the fracture cleanup after a hydraulic fracture treatment under certain pressure and temperature conditions. Parameters that alter fracture conductivity, such as polymer concentration, breaker concentration and gas flow rate, are also examined in this study. A series of experiments, using a procedure of “dynamical fracture conductivity test”, were carried out. This procedure simulates the proppant/frac fluid slurries flow into the fractures in a low-permeability rock, as it occurs in the field, using different combinations of polymer and breaker concentrations under reservoirs conditions. The result of this study provides the basis to optimize the fracturing fluids and the polymer loading at different reservoir conditions, which may result in a clean and conductive fracture. Success in improving this process will help to decrease capital expenditures and increase the production in unconventional tight gas reservoirs.

Correa Castro, Juan

2011-05-01T23:59:59.000Z

399

Stratigraphic Boundaries | Open Energy Information  

Open Energy Info (EERE)

Stratigraphic Boundaries Stratigraphic Boundaries Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Print PDF Stratigraphic Boundaries Dictionary.png Stratigraphic Boundaries: No definition has been provided for this term. Add a Definition Controlling Structures List of controlling structures typically associated with geothermal systems: Major Normal Fault Termination of a Major Normal Fault Stepover or Relay Ramp in Normal Fault Zones Apex or Salient of Normal Fault Fault Intersection Accommodation Zone Displacement Transfer Zone Pull-Apart in Strike-Slip Fault Zone Intrusion Margins and Associated Fractures Stratigraphic Boundaries Fissure Swarms Caldera Rim Margins Lithologically Controlled Hydrothermal circulation may occur at the contacts between different lithologies. Examples

400

THE STATE OF THE ART OF NUMERICAL MODELING OF THERMOHYDROLOGIC FLOW IN FRACTURED ROCK MASSES  

E-Print Network (OSTI)

improving production by hydraulic fracturing 8 the focus otfor fractures. (d) Hydraulic Fracturing: The model has been

Wang, J.S.Y.

2013-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "fracture zones faults" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


401

Hydraulic fracturing of jointed formations  

DOE Green Energy (OSTI)

Measured by volume, North America's largest hydraulic fracturing operations have been conducted at Fenton Hill, New Mexico to create geothermal energy reservoirs. In the largest operation 21,000 m/sup 3/ of water were injected into jointed granitic rock at a depth of 3.5 km. Microearthquakes induced by this injection were measured with geophones placed in five wells drilled into, or very close, to the reservoir, as well as 11 surface seismometers. The large volume of rock over which the microearthquakes were distributed indicates a mechanism of hydraulic stimulation which is at odds with conventional fracturing theory, which predicts failure along a plane which is perpendicular to the least compressive earth stress. A coupled rock mechanics/fluid flow model provides much of the explanation. Shear slippage along pre-existing joints in the rock is more easily induced than conventional tensile failure, particularly when the difference between minimum and maximum earth stresses is large and the joints are oriented at angles between 30 and 60 degrees to the principal earth stresses, and a low viscosity fluid like water is injected. Shear slippage results in local redistribution of stresses, which allows a branching, or dendritic, stimulation pattern to evolve, in agreement with the patterns of microearthquake locations. These results are qualitatively similar to the controversial process known as ''Kiel'' fracturing, in which sequential injections and shut-ins are repeated to create dendritic fractures for enhanced oil and gas recovery. However, we believe that the explanation is shear slippage of pre-existing joints and stress redistribution, not proppant bridging and fluid blocking as suggested by Kiel. 15 refs., 10 figs.

Murphy, H.D.; Fehler, M.C.

1986-01-01T23:59:59.000Z

402

Coordinated Fault Tolerance for High-Performance Computing  

SciTech Connect

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.

Dongarra, Jack; Bosilca, George; et al.

2013-04-08T23:59:59.000Z

403

Preferential flow paths and heat pipes: Results from laboratory experiments on heat-driven flow in natural and artificial rock fractures  

SciTech Connect

Water flow in fractures under the conditions of partial saturation and thermal drive may lead to fast flow along preferential localized pathways and heat pipe conditions. Water flowing in fast pathways may ultimately contact waste packages at Yucca Mountain and transport radionuclides to the accessible environment. Sixteen experiments were conducted to visualize liquid flow in glass fracture models, a transparent epoxy fracture replica, and a rock/replica fracture assembly. Spatially resolved thermal monitoring was performed in seven of these experiments to evaluate heat-pipe formation. Depending on the fracture apertures and flow conditions, various flow regimes were observed including continuous rivulet flow for high flow rates, intermittent rivulet flow and drop flow for intermediate flow rates, and film flow for low flow rates and wide apertures. These flow regimes were present in both fracture models and in the replica of a natural fracture. Heat-pipe conditions indicated by low thermal gradients were observed in five experiments. Conditions conducive to heat-pipe formation include an evaporation zone, condensation zone, adequate space for vapor and liquid to travel, and appropriate fluid driving forces. In one of the two experiments where heat pipe conditions were not observed, adequate space for liquid-vapor counterflow was not provided. Heat pipe conditions were not established in the other, because liquid flow was inadequate to compensate for imbibition and the quantity of heat contained within the rock.

Kneafsey, T.J.; Pruess, K. [Lawrence Berkeley National Lab., CA (United States). Earth Sciences Div.

1997-06-01T23:59:59.000Z

404

Fluid Flow Within Fractured Porous Media  

Science Conference Proceedings (OSTI)

Fractures provide preferential flow paths to subterranean fluid flows. In reservoir scale modeling of geologic flows fractures must be approximated by fairly simple formulations. Often this is accomplished by assuming fractures are parallel plates subjected to an applied pressure gradient. This is known as the cubic law. An induced fracture in Berea sandstone has been digitized to perform numerical flow simulations. A commercially available computational fluid dynamics software package has been used to solve the flow through this model. Single phase flows have been compared to experimental works in the literature to evaluate the accuracy with which this model can be applied. Common methods of fracture geometry classification are also calculated and compared to experimentally obtained values. Flow through regions of the fracture where the upper and lower fracture walls meet (zero aperture) are shown to induce a strong channeling effect on the flow. This model is expanded to include a domain of surrounding porous media through which the flow can travel. The inclusion of a realistic permeability in this media shows that the regions of small and zero apertures contribute to the greatest pressure losses over the fracture length and flow through the porous media is most prevalent in these regions. The flow through the fracture is shown to be the largest contributor to the net flow through the media. From this work, a novel flow relationship is proposed for flow through fractured media.

Crandall, D.M.; Ahmadi, G. (Clarkson Univ., Potsdam, NY); Smith, D.H.; Bromhal, G.S.

2006-10-01T23:59:59.000Z

405

Well test analysis in fractured media  

DOE Green Energy (OSTI)

The behavior of fracture systems under well test conditions and methods for analyzing well test data from fractured media are investigated. Several analytical models are developed to be used for analyzing well test data from fractured media. Numerical tools that may be used to simulate fluid flow in fractured media are also presented. Three types of composite models for constant flux tests are investigated. These models are based on the assumption that a fracture system under well test conditions may be represented by two concentric regions, one representing a small number of fractures that dominates flow near the well, and the other representing average conditions farther away from the well. Type curves are presented that can be used to find the flow parameters of these two regions and the extent of the inner concentric region. Several slug test models with different geometric conditions that may be present in fractured media are also investigated. A finite element model that can simulate transient fluid flow in fracture networks is used to study the behavior of various two-dimensional fracture systems under well test conditions. A mesh generator that can be used to model mass and heat flow in a fractured-porous media is presented.

Karasaki, K.

1987-04-01T23:59:59.000Z

406

Nonlinear Hertzian indentation fracture mechanics  

SciTech Connect

Indentation cracking under blunt indenters is analyzed using nonlinear fracture mechanics. The usual assumptions of linear elastic fracture mechanics have been replaced with a nonlinear load vs load-point displacement curve while assuming the material is linear elastic. The load, the load-point displacement, and a function of the crack area have been related to the crack driving force, J, while assuming a cone fracture under the Hertzian sphere. Experimentally, it was found that the load-displacement curve during loading, cracking, and unloading is nonlinear. The crack length is empirically shown to be proportional to the load-point displacement for several indenters. The experimentally measured relations between indenter load, load-point displacement, and crack geometries are then analyzed with mechanical energy balances based on the similitude of crack lengths with load-point displacements. The Hertz hardness that describes the nonlinear load vs load-point displacement relation during cracking is derived on the constant J line in load-displacement space. Finally, well-known experimental expressions that relate load to crack length are shown to be indistinguishable from the load-point displacement analysis reported.

Burns, S.J.; Chia, K.Y. [Univ. of Rochester, NY (United States). Dept. of Mechanical Engineering

1995-09-01T23:59:59.000Z

407

Naturally fractured tight gas reservoir detection optimization. Annual report, September 1993--September 1994  

Science Conference Proceedings (OSTI)

This report is an annual summarization of an ongoing research in the field of modeling and detecting naturally fractured gas reservoirs. The current research is in the Piceance basin of Western Colorado. The aim is to use existing information to determine the most optimal zone or area of fracturing using a unique reaction-transport-mechanical (RTM) numerical basin model. The RTM model will then subsequently help map subsurface lateral and vertical fracture geometries. The base collection techniques include in-situ fracture data, remote sensing, aeromagnetics, 2-D seismic, and regional geologic interpretations. Once identified, high resolution airborne and spaceborne imagery will be used to verify the RTM model by comparing surficial fractures. If this imagery agrees with the model data, then a further investigation using a three-dimensional seismic survey component will be added. This report presents an overview of the Piceance Creek basin and then reviews work in the Parachute and Rulison fields and the results of the RTM models in these fields.

NONE

1994-10-01T23:59:59.000Z

408

Proceedings of the Second International Symposium on Dynamics of Fluids in Fractured Rock  

E-Print Network (OSTI)

new fracture surface by hydraulic fracturing. Termination ofwas impossible until hydraulic fracturing was applied. ForFor conventional hydraulic fracturing, this is not crucial

Faybishenko, Boris; Witherspoon, Paul A.

2004-01-01T23:59:59.000Z

409

Acoustic Emission in a Fluid Saturated Hetergeneous Porous Layer with Application to Hydraulic Fracture  

E-Print Network (OSTI)

responses during hydraulic fracturing, and aid developmentFracture Monitoring Hydraulic fracturing is a method forfluids" used for hydraulic fracturing, the above frequencies

Nelson, J.T.

2009-01-01T23:59:59.000Z

410

The origin of high-temperature zones in vapor-dominated geothermal systems  

DOE Green Energy (OSTI)

Vapor-dominated geothermal systems are proposed to originate by downward extension (by the ''heat pipe'' mechanism) into hot dry fractured rock above a large cooling igneous intrusion. High temperature zones found by drilling are shallow parts of the original hot dry rock where the penetration of the vapor reservoir was limited, and hot dry rock may extend under much of these reservoirs. An earlier hot water geothermal system may have formed during an early phase of the heating episode.

Truesdell, Alfred H.

1991-01-01T23:59:59.000Z

411

Active Fault Segments As Potential Earthquake Sources- Inferences From  

Open Energy Info (EERE)

Active Fault Segments As Potential Earthquake Sources- Inferences From Active Fault Segments As Potential Earthquake Sources- Inferences From Integrated Geophysical Mapping Of The Magadi Fault System, Southern Kenya Rift Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Journal Article: Active Fault Segments As Potential Earthquake Sources- Inferences From Integrated Geophysical Mapping Of The Magadi Fault System, Southern Kenya Rift Details Activities (0) Areas (0) Regions (0) Abstract: Southern Kenya Rift has been known as a region of high geodynamic activity expressed by recent volcanism, geothermal activity and high rate of seismicity. The active faults that host these activities have not been investigated to determine their subsurface geometry, faulting intensity and constituents (fluids, sediments) for proper characterization of tectonic

412

Definition: Enhanced Fault Detection Technology | Open Energy Information  

Open Energy Info (EERE)

Technology Technology Jump to: navigation, search Dictionary.png Enhanced Fault Detection Technology Enhanced fault detection technology enables higher precision and greater discrimination of fault location and type with coordinated measurement among multiple devices. For distribution applications, this technology can detect and isolate faults without full-power re-closing, reducing the frequency of through-fault currents. Using high resolution sensors and fault signatures, this technology can better detect high impedance faults. For transmission applications, this technology will employ high speed communications between multiple elements (e.g., stations) to protect entire regions, rather than just single elements. It can also use the latest digital techniques to advance beyond conventional impedance relaying of

413

New method for abbreviating the fault tree graphical representation  

SciTech Connect

Fault tree analysis is being widely used for reliability and safety analysis of systems encountered in the nuclear industry and elsewhere. A disadvantage of the fault tree method is the voluminous fault tree graphical representation that conventionally results from analysis of a complex system. Previous methods for shortening the fault tree graphical representation include (1) transfers within the fault tree, and (2) the use of the SAMPLE (K out of N logic) gate, the MATRIX gate, and the SUMMATION gate. The purpose of this presentation is to introduce TABULATION gates as a method to abbreviate the fault tree graphical representation. These new gates reduce the cost of analysis and generally increase the system behavior visibility that is inherent in the fault tree technique. (auth)

Stewart, M.E.; Fussell, J.B.; Crump, R.J.

1974-12-01T23:59:59.000Z

414

Investigation of the effect of gel residue on hydraulic fracture conductivity using dynamic fracture conductivity test  

E-Print Network (OSTI)

The key to producing gas from tight gas reservoirs is to create a long, highly conductive flow path, via the placement of a hydraulic fracture, to stimulate flow from the reservoir to the wellbore. Viscous fluid is used to transport proppant into the fracture. However, these same viscous fluids need to break to a thin fluid after the treatment is over so that the fracture fluid can be cleaned up. In shallower, lower temperature (less than 250°F) reservoirs, the choice of a fracture fluid is very critical to the success of the treatment. Current hydraulic fracturing methods in unconventional tight gas reservoirs have been developed largely through ad-hoc application of low-cost water fracs, with little optimization of the process. It seems clear that some of the standard tests and models are missing some of the physics of the fracturing process in low-permeability environments. A series of the extensive laboratory "dynamic fracture conductivity" tests have been conducted. Dynamic fracture conductivity is created when proppant slurry is pumped into a hydraulic fracture in low permeability rock. Unlike conventional fracture conductivity tests in which proppant is loaded into the fracture artificially, we pump proppant/ fracturing fluid slurries into a fracture cell, dynamically placing the proppant just as it occurs in the field. Test results indicate that increasing gel concentration decreases retained fracture conductivity for a constant gas flow rate and decreasing gas flow rate decreases retained fracture conductivity. Without breaker, the damaging effect of viscous hydraulic fracturing fluids on the conductivity of proppant packs is significant at temperature of 150°F. Static conductivity testing results in higher retained fracture conductivity when compared to dynamic conductivity testing.

Marpaung, Fivman

2007-12-01T23:59:59.000Z

415

Investigation of the effect of gel residue on hydraulic fracture conductivity using dynamic fracture conductivity test  

E-Print Network (OSTI)

The key to producing gas from tight gas reservoirs is to create a long, highly conductive flow path, via the placement of a hydraulic fracture, to stimulate flow from the reservoir to the wellbore. Viscous fluid is used to transport proppant into the fracture. However, these same viscous fluids need to break to a thin fluid after the treatment is over so that the fracture fluid can be cleaned up. In shallower, lower temperature (less than 250oF) reservoirs, the choice of a fracture fluid is very critical to the success of the treatment. Current hydraulic fracturing methods in unconventional tight gas reservoirs have been developed largely through ad-hoc application of low-cost water fracs, with little optimization of the process. It seems clear that some of the standard tests and models are missing some of the physics of the fracturing process in low-permeability environments. A series of the extensive laboratory “dynamic fracture conductivity” tests have been conducted. Dynamic fracture conductivity is created when proppant slurry is pumped into a hydraulic fracture in low permeability rock. Unlike conventional fracture conductivity tests in which proppant is loaded into the fracture artificially, we pump proppant/ fracturing fluid slurries into a fracture cell, dynamically placing the proppant just as it occurs in the field. Test results indicate that increasing gel concentration decreases retained fracture conductivity for a constant gas flow rate and decreasing gas flow rate decreases retained fracture conductivity. Without breaker, the damaging effect of viscous hydraulic fracturing fluids on the conductivity of proppant packs is significant at temperature of 150oF. Static conductivity testing results in higher retained fracture conductivity when compared to dynamic conductivity testing.

Marpaung, Fivman

2007-12-01T23:59:59.000Z

416

Using seismic tomography to characterize fracture systems induced by hydraulic fracturing  

DOE Green Energy (OSTI)

Microearthquakes induced by hydraulic fracturing have been studied by many investigators to characterize fracture systems created by the fracturing process and to better understand the locations of energy resources in the earth`s subsurface. The pattern of the locations often contains a great deal of information about the fracture system stimulated during the hydraulic fracturing. Seismic tomography has found applications in many areas for characterizing the subsurface of the earth. It is well known that fractures in rock influence both the P and S velocities of the rock. The influence of the fractures is a function of the geometry of the fractures, the apertures and number of fractures, and the presence of fluids in the fractures. In addition, the temporal evolution of the created fracture system can be inferred from the temporal changes in seismic velocity and the pattern of microearthquake locations. Seismic tomography has been used to infer the spatial location of a fracture system in a reservoir that was created by hydraulic fracturing.

Fehler, M.; Rutledge, J.

1995-01-01T23:59:59.000Z

417

Weathering of the Rio Blanco Quartz Diorite, Luquillo Mountains, Puerto Rico: Coupling Oxidation, Dissolution, And Fracturing  

Science Conference Proceedings (OSTI)

In the mountainous Rio Icacos watershed in northeastern Puerto Rico, quartz diorite bedrock weathers spheroidally, producing a 0.2-2 m thick zone of partially weathered rock layers ({approx}2.5 cm thickness each) called rindlets, which form concentric layers around corestones. Spheroidal fracturing has been modeled to occur when a weathering reaction with a positive {Delta}V of reaction builds up elastic strain energy. The rates of spheroidal fracturing and saprolite formation are therefore controlled by the rate of the weathering reaction. Chemical, petrographic, and spectroscopic evidence demonstrates that biotite oxidation is the most likely fracture-inducing reaction. This reaction occurs with an expansion in d (0 0 1) from 10.0 to 10.5 {angstrom}, forming 'altered biotite'. Progressive biotite oxidation across the rindlet zone was inferred from thin sections and gradients in K and Fe(II). Using the gradient in Fe(II) and constraints based on cosmogenic age dates, we calculated a biotite oxidation reaction rate of 8.2 x 10{sup -14} mol biotite m{sup -2} s{sup -1}. Biotite oxidation was documented within the bedrock corestone by synchrotron X-ray microprobe fluorescence imaging and XANES. X-ray microprobe images of Fe(II) and Fe(III) at 2 {micro}m resolution revealed that oxidized zones within individual biotite crystals are the first evidence of alteration of the otherwise unaltered corestone. Fluids entering along fractures lead to the dissolution of plagioclase within the rindlet zone. Within 7 cm surrounding the rindlet-saprolite interface, hornblende dissolves to completion at a rate of 6.3 x 10{sup -13} mol hornblende m{sup -2} s{sup -1}: the fastest reported rate of hornblende weathering in the field. This rate is consistent with laboratory-derived hornblende dissolution rates. By revealing the coupling of these mineral weathering reactions to fracturing and porosity formation we are able to describe the process by which the quartz diorite bedrock disaggregates and forms saprolite. In the corestone, biotite oxidation induces spheroidal fracturing, facilitating the influx of fluids that react with other minerals, dissolving plagioclase and chlorite, creating additional porosity, and eventually dissolving hornblende and precipitating secondary minerals. The thickness of the resultant saprolite is maintained at steady state by a positive feedback between the denudation rate and the weathering advance rate driven by the concentration of pore water O{sub 2} at the bedrock-saprolite interface.

Buss, H.L.; Sak, P.B.; Webb, S.M.; Brantley, S.L.

2009-05-12T23:59:59.000Z

418

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

Science Conference Proceedings (OSTI)

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.

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

2004-07-01T23:59:59.000Z

419

Apparatus and method for monitoring underground fracturing  

DOE Patents (OSTI)

An apparatus and method for measuring deformation of a rock mass around the vicinity of a fracture, commonly induced by hydraulic