Sample records for outflow fracture permeability

  1. Fracture Propagation Driven by Fluid Outflow from a Low-permeability Reservoir

    E-Print Network [OSTI]

    Gor, Gennady Yu

    2012-01-01T23:59:59.000Z

    Fracturing of the caprock during CO2 storage in deep saline aquifers can lead to leakage. Estimation of the rate of fracture propagation allows one to assess the leakage risk. Here we propose an analytical model for calculating the length of the fracture, which propagates due to the fluid outflow from a low-permeability aquifer. We present a self-similar solution of the pressure diffusion equation in the system of reservoir and fracture, allowing us to get the analytical expression for the fracture length as a function of time. We calculate the evolution of the fracture length for a characteristic aquifer. We show that the analytical solution provides an estimate from below for the fracture length, since the driving force for propagation grows with elevation.

  2. Relative Permeability of Fractured Rock

    SciTech Connect (OSTI)

    Mark D. Habana

    2002-06-30T23:59:59.000Z

    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.

  3. Fracture permeability and seismic wave scattering ŒPoroelastic ...

    E-Print Network [OSTI]

    Seiji Nakagawa

    2010-02-03T23:59:59.000Z

    Jun 18, 2010 ... The new model contains fracture permeability in the plan-parallel direction. ... Division of Chemical Sciences of the U.S. Department of Energy ...

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

    Open Energy Info (EERE)

    deposits along fault zones can potentially provide a tool for studying fault-zone evolution. Authors Daniel Curewitz and Jeffrey A. Karson Published Journal Journal of...

  5. Structural Settings Of Hydrothermal Outflow- Fracture Permeability

    Open Energy Info (EERE)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page onYou are now leaving Energy.gov You are now leaving Energy.gov You are beingZealand Jump to:Ezfeedflag JumpID-f <Maintained By Fault Propagation And Interaction | Open Energy

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

    Open Energy Info (EERE)

    Nevada, Geothermal Field Jump to: navigation, search OpenEI Reference LibraryAdd to library Conference Paper: Reservoir-Scale Fracture Permeability in the Dixie Valley,...

  7. Permeability and Dispersion Coefficients in Rocks with Fracture Network - 12140

    SciTech Connect (OSTI)

    Lee, C.K.; Htway, M.Z. [Handong Global University, 3 Namsong-ri, Heunghae-eub, Buk-gu, Pohang, Kyungbuk, 791-708 (Korea, Republic of); Yim, S.P. [Korea Atomic Energy Research Institute, P.O.Box 150, Yusong, Daejon, 305-600 (Korea, Republic of)

    2012-07-01T23:59:59.000Z

    Fluid flow and solute transport are considered for a rock medium with a fracture network with regard to the effective permeability and the dispersion coefficients. To investigate the effects of individual fractures a three-fracture system is chosen in which two are parallel and the third one connects the two at different angles. Specifically the micro-cell boundary-value problems(defined through multiple scale analysis) are solved numerically by using finite elements to calculate the permeability and dispersion coefficients. It is shown that the permeability depends significantly on the pattern of the fracture distribution and the dispersion coefficient is influenced by both the externally imposed pressure gradient (which also reflects the flow field) and the direction of the gradient of solute concentration on the macro-scale. From the calculations of the permeability and dispersion coefficients for solute in a rock medium with a fracture network the following conclusions are drawn. 1. The permeability of fractured medium depends on the primary orientation of the fracture network and is influenced by the connecting fractures in the medium. 2. The cross permeability, e.g., permeability in the direction normal to the direction of the external pressure gradient is rather insensitive to the orientation of the fracture network. 3. Calculation of permeability is most efficiently achieved with optimal discretization across individual fractures and is rather insensitive to the discretization along the fracture.. 4. The longitudinal dispersion coefficient Dxx of a fractured medium depends on both the macro-scale concentration gradient and the direction of the flow (pressure gradient). Hence both features must be considered when investigating solute transport in a fractured medium. (authors)

  8. Fracture permeability and seismic wave scattering--Poroelastic linear-slip interface model for heterogeneous fractures

    SciTech Connect (OSTI)

    Nakagawa, S.; Myer, L.R.

    2009-06-15T23:59:59.000Z

    Schoenberg's Linear-slip Interface (LSI) model for single, compliant, viscoelastic fractures has been extended to poroelastic fractures for predicting seismic wave scattering. However, this extended model results in no impact of the in-plane fracture permeability on the scattering. Recently, we proposed a variant of the LSI model considering the heterogeneity in the in-plane fracture properties. This modified model considers wave-induced, fracture-parallel fluid flow induced by passing seismic waves. The research discussed in this paper applies this new LSI model to heterogeneous fractures to examine when and how the permeability of a fracture is reflected in the scattering of seismic waves. From numerical simulations, we conclude that the heterogeneity in the fracture properties is essential for the scattering of seismic waves to be sensitive to the permeability of a fracture.

  9. Low permeability gas reservoir production using large hydraulic fractures

    E-Print Network [OSTI]

    Holditch, Stephen A

    1970-01-01T23:59:59.000Z

    extending up to three thousand feet from the producing well. Also, a model simulating a nuclear cavity was designed. This model simulated a well containing an eighty foot radius cavity with a fractured zone of one hundred times the reservoir permeability... of each system was prepared. The results of this study showed that all fractures of greater than one thousand foot radius had greater productivity and greater cumu- lative gas produced than did the nuclear cavity. It appears that large hydraulic...

  10. Property measurement and correlation for homogeneous and naturally fractured low permeability cores

    E-Print Network [OSTI]

    Fan, Jin

    1993-01-01T23:59:59.000Z

    pseudopressures for fracture permeabilities of I, 10, 100, and 1000 md are plotted versus time, with other parameters being constant. Fig, 6. 3 shows that as fracture permeability increases, the convergence time decreases because the rate of gas flow from...

  11. Determination of formation permeability using back-pressure test data from hydraulically-fractured, low-permeability gas wells

    E-Print Network [OSTI]

    Krawtz, John Paul

    1984-01-01T23:59:59.000Z

    DETERMINATION OF FORMATION PERMEABILITY USING BACX-PRESSURE TEST DATA FROM HYDRAULICALLY-FRACTURED, LOW-PERMEABILITY GAS WELLS A Thesis JOHN PAUL KRAWTZ Submitted to the Graduate College of Texas AsJ4 University in partial fulfillment... of the requirements for the degree of MASTER OF SCIENCE August 1984 Major subject: petroleum Engineering DETERMINATION OF FORMATION PERMEABILITY USING BACK-PRESSURE TEST DATA FROM HYDRAULICALLY-FRACTURED, LOW-PERMEABILITY GAS WELLS A Thesis JOHN PAUL KRAWTZ...

  12. Modelling effective permeability of fracture networks in permeable rock formation by

    E-Print Network [OSTI]

    Paris-Sud XI, Université de

    such as underground nuclear waste disposal in claystone, geological CO2 storage or hydrocabure reservoir in a fractured porous rock are used to investigate its effective permeability. If the far field inflow is uniform, the theoretical solution shows that the pressure field in the matrix is a function of the discharge

  13. STRUCTURE OF THE LOW PERMEABLE NATURALLY FRACTURED GEOTHERMAL RESERVOIR Chrystel Dezayes*, Albert Genter** & Benot Valley ***

    E-Print Network [OSTI]

    Paris-Sud XI, Université de

    1 STRUCTURE OF THE LOW PERMEABLE NATURALLY FRACTURED GEOTHERMAL RESERVOIR AT SOULTZ Chrystel cluster appears as a fractured reservoir developed within a low permeable matrix. Fracture zones represent) where reservoir development involved the reactivation of the pre- existing fractures in the granite [16

  14. A New Coal-Permeability Model: Internal Swelling Stress and Fracture–Matrix Interaction

    E-Print Network [OSTI]

    Liu, Hui-Hai; Rutqvist, Jonny

    2010-01-01T23:59:59.000Z

    L. : Adsorption-induced coal swelling and stress:acid gas sequestration into coal seams. J Geophys. Res. (fracturing on permeability of coal. Min. Sci. Technol. 3,

  15. 3.3 NUMERICAL MODELING OF SOLID DEFORMATION AND STRESS-DEPENDENT PERMEABILITY IN NATURALLY FRACTURED

    E-Print Network [OSTI]

    Schechter, David S.

    permeability. When the pore pressure depletes due to oil/gas production rates in highly stress FRACTURED RESERVOIRS During the first year of this project, we analyzed the productivity behavior was demonstrated. 3.3.1 Introduction Fractures are the main fluid flow paths in naturally fractured reservoirs

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

    SciTech Connect (OSTI)

    Min, Ki-Bok; Rutqvist, J.; Tsang, Chin-Fu; Jing, Lanru

    2004-04-30T23:59:59.000Z

    We investigate the stress-dependent permeability issue in fractured rock masses considering the effects of nonlinear normal deformation and shear dilation of fractures using a two-dimensional distinct element method program, UDEC, based on a realistic discrete fracture network realization. A series of ''numerical'' experiments were conducted to calculate changes in the permeability of simulated fractured rock masses under various loading conditions. Numerical experiments were conducted in two ways: (1) increasing the overall stresses with a fixed ratio of horizontal to vertical stresses components; and (2) increasing the differential stresses (i.e., the difference between the horizontal and vertical stresses) while keeping the magnitude of vertical stress constant. These numerical experiments show that the permeability of fractured rocks decreases with increased stress magnitudes when the stress ratio is not large enough to cause shear dilation of fractures, whereas permeability increases with increased stress when the stress ratio is large enough. Permeability changes at low stress levels are more sensitive than at high stress levels due to the nonlinear fracture normal stress-displacement relation. Significant stress-induced channeling is observed as the shear dilation causes the concentration of fluid flow along connected shear fractures. Anisotropy of permeability emerges with the increase of differential stresses, and this anisotropy can become more prominent with the influence of shear dilation and localized flow paths. A set of empirical equations in closed-form, accounting for both normal closure and shear dilation of the fractures, is proposed to model the stress-dependent permeability. These equations prove to be in good agreement with the results obtained from our numerical experiments.

  17. Analytical and Numerical Solutions for the Case of a Horizontal Well with a Radial Power-Law Permeability Distribution--Comparison to the Multi-Fracture Horizontal Case

    E-Print Network [OSTI]

    Broussard, Ryan Sawyer

    2013-02-08T23:59:59.000Z

    . The unstimulated outer region has homogeneous reservoir properties. The current norm for successful stimulation of low permeability reservoir rocks is multi-stage hydraulic fracturing. The process of hydraulic fracturing creates thin, high permeability fractures...

  18. Stress- and Chemistry-Mediated Permeability Enhancement/Degradation in Stimulated Critically-Stressed Fractures

    SciTech Connect (OSTI)

    Derek Elsworth; Abraham S. Grader; Chris Marone; Phillip Halleck; Peter Rose; Igor Faoro; Joshua Taron; André Niemeijer; Hideaki Yasuhara

    2009-03-30T23:59:59.000Z

    This work has investigated the interactions between stress and chemistry in controlling the evolution of permeability in stimulated fractured reservoirs through an integrated program of experimentation and modeling. Flow-through experiments on natural and artificial fractures in Coso diorite have examined the evolution of permeability under paths of mean and deviatoric stresses, including the role of dissolution and precipitation. Models accommodating these behaviors have examined the importance of incorporating the complex couplings between stress and chemistry in examining the evolution of permeability in EGS reservoirs. This document reports the findings of experiment [1,2] and analysis [3,4], in four sequential chapters.

  19. Fracture Propagation and Permeability Change under Poro-thermoelastic Loads & Silica Reactivity in Enhanced Geothermal Systems

    SciTech Connect (OSTI)

    Ahmad Ghassemi

    2009-10-01T23:59:59.000Z

    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. Therefore, knowledge of the conditions leading to formation of fractures and fracture networks is of paramount importance. Furthermore, in the absence of natural fractures or adequate connectivity, artificial fractures are created in the reservoir using hydraulic fracturing. 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 developed advanced poro-thermo-chemo-mechanical fracture models for rock fracture research in support of EGS design. The fracture propagation models are based on a regular displacement discontinuity formulation. The fracture propagation studies include modeling interaction of induced fractures. In addition to the fracture propagation studies, two-dimensional solution algorithms have been developed and used to estimate the impact of pro-thermo-chemical processes on fracture permeability and reservoir pressure. Fracture permeability variation is studied using a coupled thermo-chemical model with quartz reaction kinetics. The model is applied to study quartz precipitation/dissolution, as well as the variation in fracture aperture and pressure. Also, a three-dimensional model of injection/extraction has been developed to consider the impact poro- and thermoelastic stresses on fracture slip and injection pressure. These investigations shed light on the processes involved in the observed phenomenon of injection pressure variation (e.g., in Coso), and allow the assessment of the potential of thermal and chemical stimulation strategies.

  20. A new coal-permeability model: Internal swelling stress and fracture-matrix interaction

    SciTech Connect (OSTI)

    Liu, H.H.; Rutqvist, J.

    2009-10-01T23:59:59.000Z

    We have developed a new coal-permeability model for uniaxial strain and constant confining stress conditions. The model is unique in that it explicitly considers fracture-matrix interaction during coal deformation processes and is based on a newly proposed internal-swelling stress concept. This concept is used to account for the impact of matrix swelling (or shrinkage) on fracture-aperture changes resulting from partial separation of matrix blocks by fractures that do not completely cut through the whole matrix. The proposed permeability model is evaluated with data from three Valencia Canyon coalbed wells in the San Juan Basin, where increased permeability has been observed during CH{sub 4} gas production, as well as with published data from laboratory tests. Model results are generally in good agreement with observed permeability changes. The importance of fracture-matrix interaction in determining coal permeability, demonstrated in this work using relatively simple stress conditions, underscores the need for a dual-continuum (fracture and matrix) mechanical approach to rigorously capture coal-deformation processes under complex stress conditions, as well as the coupled flow and transport processes in coal seams.

  1. An experimental study of the permeability of fracture intersections in Sioux quartzite

    E-Print Network [OSTI]

    Juddo, Edward Paul

    1986-01-01T23:59:59.000Z

    ) experiment (If26). 26 I. OO 0. 80 co IO V 0. 60 OAO Second Loading 0. 20 First Loading 26 (2) 24 0 0 20 40 60 80 IOO P (MPa) Figure 5. Normalized fracture permeability (kf/kf3 6) versus confin- ing pressure (PC) for fractured cohesive... specimens (FCS), second-loading cycle. (2) indicates two-intersecting-fractures (TIF) experiments (f26 5 38). 33 I. OO 0. 80 co ro 0. 60 0. 40 40 FCS 0. 20 1' FNCS 38 (2) 37 42 0 0 20 40 60 80 [00 Pc (MPa Figure 10. Normalized fracture...

  2. Multiporosity Flow in Fractured Low-Permeability Rocks

    E-Print Network [OSTI]

    Kuhlman, Kristopher L; Heath, Jason E

    2015-01-01T23:59:59.000Z

    A multiporosity extension of classical double and triple porosity fractured rock flow models for slightly compressible fluids is presented. The multiporosity model is an adaptation of the multirate solute transport model of Haggerty and Gorelick (1995) to viscous flow in fractured rock reservoirs. It is a generalization of both pseudo-steady-state and transient interporosity flow double porosity models. The model includes a fracture continuum and an overlapping distribution of multiple rock matrix continua, whose fracture-matrix exchange coefficients are specified through a discrete probability mass function. Semi-analytical cylindrically symmetric solutions to the multiporosity mathematical model are developed using the Laplace transform to illustrate its behavior. The multiporosity model presented here is conceptually simple, yet flexible enough to simulate common conceptualizations of double and triple porosity flow. This combination of generality and simplicity makes the multiporosity model a good choice ...

  3. A Permeability Model for Coal and Other Fractured, Sorptive-Elastic Media

    SciTech Connect (OSTI)

    Eric P. Robertson; Richard L. Christiansen

    2006-10-01T23:59:59.000Z

    This paper describes the derivation of a new equation that can be used to model the permeability behavior of a fractured, sorptive-elastic media, such as coal, under variable stress conditions commonly used during measurement of permeability data in the laboratory. The model is derived for cubic geometry under biaxial or hydrostatic confining pressures. The model is also designed to handle changes in permeability caused by adsorption and desorption of gases from the matrix blocks. The model equations can be used to calculate permeability changes caused by the production of methane from coal as well as the injection of gases, such as carbon dioxide, for sequestration in coal. Sensitivity analysis of the model found that each of the input variables can have a significant impact on the outcome of the permeability forecast as a function of changing pore pressure; thus, accurate input data are essential. The permeability model can also be used as a tool to determine input parameters for field simulations by curve-fitting laboratory-generated permeability data. The new model is compared to two other widely used coal permeability models using a hypothetical coal with average properties.

  4. Fractured gas well analysis: evaluation of in situ reservoir properties of low permeability gas wells stimulated by finite conductivity hydraulic fractures

    E-Print Network [OSTI]

    Makoju, Charles Adoiza

    1978-01-01T23:59:59.000Z

    FRACTURED GAS WELL ANALYSIS - EVALUATION OF IN SITU RESERVOIR PROPERTIES OF LOW PERMEABILITY GAS WELLS STIMULATED BY FINITE CONDUCTIVITY HYDRAULIC FRACTURES A Thesis by CHARLES ADOIZA MAKOJU Submitted to the Graduate College of Texas AQ1... BY FINITE CONDUCTIVITY HYDRAULIC FRACTURES A Thesis by CHARLES ADOIZA MAKOJU Approved as to style and content by: C a~ an o ommsttee Member Member em er Hea o Department December 1978 ABSTRACT FRACTURED GAS HELL ANALYSIS - EVALUATION OF IN SITU...

  5. Stimulation results in the low-permeability Wasatch formation - An evolution to foam fracturing

    SciTech Connect (OSTI)

    Harris, P.C.; Bailey, D.E.; Evertz, G.L.

    1984-05-01T23:59:59.000Z

    The Wasatch Formation of the Uinta Basin in eastern Utah is typical of many formations in the Rocky Mountains, having low permeability and high sensitivity to water. Stimulation treatments with several types of fracturing fluids, including oilwater emulsion fluids, complex gel fluids and foam fluids, have been generally successful. Production decline curves from twenty four wells in the field were used for comparison of the different stimulation methods. Although foam fracturing has been used for the shortest period of time, comparison of the production histories show the relatively higher efficiency of the foam fracturing treatments compared to other stimulation methods in the Wasatch formation. Foam fluids gave higher production rates and higher flowing pressures than offset wells fractured with complex gel fluids. A stimulation model for oil and gas production was used to match the production history from this reservoir. The model allowed a projection of gas production based on early production from the wells and knowledge of the reservoir.

  6. Modeling Mud-Filtrate Invasion Effects on Resistivity Logs to Estimate Permeability of Vuggy and Fractured Carbonate Formations

    E-Print Network [OSTI]

    Torres-Verdín, Carlos

    measurements with conventional and non- conventional well logs to calculate static and dynamic petrophysical/or fractures in the displacement of hydrocarbons by mud filtrate. Introduction Permeability estimation is one

  7. Oil recovery enhancement from fractured, low permeability reservoirs. Annual report 1990--1991, Part 1

    SciTech Connect (OSTI)

    Poston, S.W.

    1991-12-31T23:59:59.000Z

    Joint funding by the Department of Energy and the State of Texas has Permitted a three year, multi-disciplinary investigation to enhance oil recovery from a dual porosity, fractured, low matrix permeability oil reservoir to be initiated. The Austin Chalk producing horizon trending thru the median of Texas has been identified as the candidate for analysis. Ultimate primary recovery of oil from the Austin Chalk is very low because of two major technological problems. The commercial oil producing rate is based on the wellbore encountering a significant number of natural fractures. The prediction of the location and frequency of natural fractures at any particular region in the subsurface is problematical at this time, unless extensive and expensive seismic work is conducted. A major portion of the oil remains in the low permeability matrix blocks after depletion because there are no methods currently available to the industry to mobilize this bypassed oil. The following multi-faceted study is aimed to develop new methods to increase oil and gas recovery from the Austin Chalk producing trend. These methods may involve new geological and geophysical interpretation methods, improved ways to study production decline curves or the application of a new enhanced oil recovery technique. The efforts for the second year may be summarized as one of coalescing the initial concepts developed during the initial phase to more in depth analyses. Accomplishments are predicting natural fractures; relating recovery to well-log signatures; development of the EOR imbibition process; mathematical modeling; and field test.

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

    SciTech Connect (OSTI)

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

    2008-09-30T23:59:59.000Z

    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.

  9. Critical Chemical-Mechanical Couplings that Define Permeability Modifications in Pressure-Sensitive Rock Fractures

    SciTech Connect (OSTI)

    Derek Elsworth; Abraham Grader; Susan Brantley

    2007-04-25T23:59:59.000Z

    This work examined and quantified processes controlling changes in the transport characteristics of natural fractures, subjected to coupled thermal-mechanical-chemical (TMC) effects. Specifically, it examined the effects of mineral dissolution and precipitation mediated by mechanical effects, using laboratory through-flow experiments concurrently imaged by X-ray CT. These were conducted on natural and artificial fractures in cores using water as the permeant. Fluid and mineral mass balances are recorded and are correlated with in-sample saturation, porosity and fracture aperture maps, acquired in real-time by X-ray CT-imaging at a maximum spatial resolution of 15-50 microns per pixel. Post-test, the samples were resin-impregnated, thin-sectioned, and examined by microscopy to define the characteristics of dissolution and precipitation. The test-concurrent X-ray imaging, mass balances, and measurements of permeability, together with the post-test microscopy, were used to define dissolution/precipitation processes, and to constrain process-based models. These models define and quantify key processes of pressure solution, free-face dissolution, and shear-dilation, and the influence of temperature, stress level, and chemistry on the rate of dissolution, its distribution in space and time, and its influence on the mechanical and transport properties of the fracture.

  10. Modelling of steady-state fluid flow in 3D fractured isotropic porous media: Application to effective permeability calculation

    E-Print Network [OSTI]

    Paris-Sud XI, Université de

    -Est, Laboratoire Navier (ENPC-IFSTTAR-CNRS) 77455 Marne la Vallée, France 2 BRGM, Risks Division, F-45060 Orléans, geological CO2 storage, geothermal energy, etc. However, determining effective permeability for fractured reservoirs for a long time [1-4]. DFN is introduced in several commercial softwares as UDEC (Itasca) [5

  11. Numerical Modeling of Fracture Permeability Change in Naturally Fractured Reservoirs Using a Fully Coupled Displacement Discontinuity Method.

    E-Print Network [OSTI]

    Tao, Qingfeng

    2010-07-14T23:59:59.000Z

    finite difference method to solve the fluid flow in fractures, a fully coupled displacement discontinuity method to build the global relation of fracture deformation, and the Barton-Bandis model of fracture deformation to build the local relation...

  12. Liquid-Gas Relative Permeabilities in Fractures: Effects of Flow Structures, Phase Transformation and Surface

    E-Print Network [OSTI]

    Stanford University

    Transformation and Surface Roughness Chih-Ying Chen June 2005 Financial support was provided through the Stanford permeabilities, accounting for phase transformations, the inviscid bubble train models coupled with relative permeability concepts were developed. The phase transformation effects were evaluated by accounting

  13. Upscaling permeability for fractured concrete: meso-macro numerical approach coupled to strong discontinuities

    E-Print Network [OSTI]

    - cations in Civil engineering such as geological CO2 storage or civil nuclear industry. In France, the latter aims at extending its nuclear powerplants lifetime which requires accurate quantifications of the outflow through the concrete vessel along different cases and accounting for the long-term evolution

  14. Permeability Estimation from Fracture Calibration Test Analysis in Shale and Tight Gas

    E-Print Network [OSTI]

    Xue, Han 1988-

    2012-12-13T23:59:59.000Z

    to these two tests, a step-rate test is sometimes conducted before a mini-fracture test to determine fracture extension pressure. (Figure 2. 1) In tight gas or shale gas formation the short and low rate injection-fall off test using slick water as injection...

  15. Predicting flow through low-permeability, partially saturated, fractured rock: A review of modeling and experimental efforts at Yucca Mountain

    SciTech Connect (OSTI)

    Eaton, R.R.; Bixler, N.E.; Glass, R.J.

    1989-11-01T23:59:59.000Z

    Current interest in storing high-level nuclear waste in underground repositories has resulted in an increased effort to understand the physics of water flow through low-permeability rock. The US Department of Energy is investigating a prospective repository site located in volcanic ash (tuff) hundreds of meters above the water table at Yucca Mountain, Nevada. Consequently, mathematical models and experimental procedures are being developed to provide a better understanding of the hydrology of this low-permeability, partially saturated, fractured rock. Modeling water flow in the vadose zone in soils and in relatively permeable rocks such as sandstone has received considerable attention for many years. The treatment of flow (including nonisothermal conditions) through materials such as the Yucca Mountain tuffs, however, has not received the same level of attention, primarily because it is outside the domain of agricultural and petroleum technology. This paper reviews the status of modeling and experimentation currently being used to understand and predict water flow at the proposed repository site. Several areas of research needs emphasized by the review are outlined. The extremely nonlinear hydraulic properties of these tuffs in combination with their heterogeneous nature makes it a challenging and unique problem from a computational and experimental view point. 101 refs., 14 figs., 1 tab.

  16. Mechanical and transport properties of rocks at high temperatures and pressures. Task II: fracture permeability of crystalline rocks as a function of temperature, pressure, and hydrothermal alteration

    SciTech Connect (OSTI)

    Not Available

    1981-01-01T23:59:59.000Z

    The primary objective is to measure and understand the variation of the fracture permeability of quartzite subjected to hydrothermal conditions. Pore fluids will consist of distilled water and aqueous Na/sub 2/CO/sub 3/ solutions at temperatures to 250/sup 0/C, fluid pressures to 20 MPa and effective normal stresses to 70 MPa. Fluid flow rates will be controllable to rates at least as small as 0.2 ml/day (approx. 4 fracture volumes). Experiments are designed to assess what role, if any, pressure solution may play at time scales of those of the experiments (less than or equal to 2 weeks). Secondary objectives are: (1) continue simulated fracture studies, incorporating inelastic deformation into model and characterize the nature of inelastic deformation occurring on loaded tensile fractures in quartzite; (2) continue dissolution experiment, with emphasis on dissolution modification of tensile fracture surfaces on quartzite; and (3) study natural fractures in a quartzite exhibiting hydrothermal dissolution features.

  17. Gas Permeability of Fractured Sandstone/Coal Samples under Variable Confining Pressure

    E-Print Network [OSTI]

    Liu, Weiqun; Li, Yushou; Wang, Bo

    2010-01-01T23:59:59.000Z

    argillite under con?nement: gas and water testing. Phys.Gascoyne, M. , Wuschke, D.M. : Gas migration through water-fractured rock: results of a gas injection test. J.

  18. Upscaling permeability for fractured concrete: meso-macro numerical approach coupled to strong discontinuities

    E-Print Network [OSTI]

    Métiers ParisTech, France Abstract A two scales numerical analysis is set up in order to upscale, in the spirit of sequential multi-scale methods [7]. The latter tend to build macroscopic models from a sequence discon- tinuities) representing fine scale cracks to the fine scale permeability tensor. The latter may

  19. Property measurement and correlation for homogeneous and naturally fractured low permeability cores 

    E-Print Network [OSTI]

    Fan, Jin

    1993-01-01T23:59:59.000Z

    pulse method. The principles of pressure pulse test are reviewed and the new laboratory equipment is described in this thesis. The new laboratory technique can be used to determine (1) the porosity of the matrix, (2) the permeability of the matrix, (3...

  20. OVERBURDEN PRESSURE AFFECTS FRACTURE APERTURE

    E-Print Network [OSTI]

    Schechter, David S.

    OVERBURDEN PRESSURE AFFECTS FRACTURE APERTURE AND FRACTURE PERMEABILITY IN A FRACTURED RESERVOIR are in integrated reservoir study, reservoir charac- terization, naturally fractured reservoirs, waterflooding in Hydraulically and Naturally Fractured Reservoirs." His research areas include experimental analysis

  1. A comparative simulation study of coupled THM processes and their effect on fractured rock permeability around nuclear waste repositories

    E-Print Network [OSTI]

    Rutqvist, Jonny

    2008-01-01T23:59:59.000Z

    hydrothermomechanical design of nuclear waste repositories.Associated with Nuclear Waste Repositories, Academic Press,rock permeability around nuclear waste repositories Jonny

  2. The effects of damage in and around a fracture upon the analysis of pressure data from low permeability gas wells

    E-Print Network [OSTI]

    Fox, Thomas Lee

    1980-01-01T23:59:59.000Z

    Buildup Data for a 100 Foot Fracture in an Unbounded Reservoir 15 16 Horner Plot of Pressure Buildup Data for a 100 Foot Fracture in an Unbounded Reservoir--Closure and non- Darcy Flow Included 17 Horner Plot of Pressure Buildup Data for a 100 Foot... Fracture in an Unbounded Reservoir--Closure and non- Darcy Flow Included--500 MCFPD Rate 18 10 Horner Plot of Pressure Buildup Data for a 100 Foot Fracture in an Unbounded Reservoir--Closure and non- Darcy Flow Included--1000 MCFPD Rate...

  3. X-231A demonstration of in-situ remediation of DNAPL compounds in low permeability media by soil fracturing with thermally enhanced mass recovery or reactive barrier destruction

    SciTech Connect (OSTI)

    Siegrist, R.L. [Oak Ridge National Lab., TN (United States)] [Oak Ridge National Lab., TN (United States); [Colorado School of Mines, Golden, CO (United States). Environmental Science and Engineering Div.; Lowe, K.S. [Oak Ridge National Lab., Grand Junction, CO (United States). Life Sciences Div.] [Oak Ridge National Lab., Grand Junction, CO (United States). Life Sciences Div.; Murdoch, L.D. [FRx, Inc., Cincinnati, OH (United States)] [FRx, Inc., Cincinnati, OH (United States); [Clemson Univ., SC (United States); Slack, W.W. [FRx, Inc., Cincinnati, OH (United States)] [FRx, Inc., Cincinnati, OH (United States); Houk, T.C. [Lockheed Martin Energy Systems, Piketon, OH (United States)] [Lockheed Martin Energy Systems, Piketon, OH (United States)

    1998-03-01T23:59:59.000Z

    The overall goal of the program of activities is to demonstrate robust and cost-effective technologies for in situ remediation of DNAPL compounds in low permeability media (LPM), including adaptations and enhancements of conventional technologies to achieve improved performance for DNAPLs in LPM. The technologies sought should be potential for application at simple, small sites (e.g., gasoline underground storage tanks) as well as at complex, larger sites (e.g., DOE land treatment units). The technologies involved in the X-231A demonstration at Portsmouth Gaseous Diffusion Plant (PORTS) utilized subsurface manipulation of the LPM through soil fracturing with thermally enhanced mass recovery or horizontal barrier in place destruction. To enable field evaluation of these approaches, a set of four test cells was established at the X-231A land treatment unit at the DOE PORTS plant in August 1996 and a series of demonstration field activities occurred through December 1997. The principal objectives of the PORTS X-231A demonstration were to: determine and compare the operational features of hydraulic fractures as an enabling technology for steam and hot air enhanced soil vapor extraction and mass recovery, in situ interception and reductive destruction by zero valent iron, and in situ interception and oxidative destruction by potassium permanganate; determine the interaction of the delivered agents with the LPM matrix adjacent to the fracture and within the fractured zone and assess the beneficial modifications to the transport and/or reaction properties of the LPM deposit; and determine the remediation efficiency achieved by each of the technology strategies.

  4. Simulation of fluid flow mechanisms in high permeability zones (Super-K) in a giant naturally fractured carbonate reservoir

    E-Print Network [OSTI]

    Abu-Hassoun, Amer H.

    2009-05-15T23:59:59.000Z

    and fractures were treated as two systems. Reservoir management practices and decisions should be very carefully reviewed and executed in this dual continuum reservoir based on the results of this work. Studying this dual media flow behavior is vital for better...

  5. METHOD DEVELOPMENT FOR DETERMINING THE HYDRAULIC CONDUCTIVITY OF FRACTURED POROUS MEDIA

    SciTech Connect (OSTI)

    Dixon, K.

    2013-09-30T23:59:59.000Z

    Plausible, but unvalidated, theoretical model constructs for unsaturated hydraulic conductivity of fractured porous media are currently used in Performance Assessment (PA) modeling for cracked saltstone and concrete (Flach 2011). The Nuclear Regulatory Commission (NRC) has expressed concern about the lack of model support for these assumed Moisture Characteristic Curves (MCC) data, as noted in Requests for Additional Information (RAIs) PA-8 and SP-4 (Savannah River Remediation, LLC, 2011). The objective of this task was to advance PA model support by developing an experimental method for determining the hydraulic conductivity of fractured cementitious materials under unsaturated conditions, and to demonstrate the technique on fractured saltstone samples. The task was requested through Task Technical Request (TTR) HLW-SSF-TTR-2012-0016 and conducted in accordance with Task Technical & Quality Assurance Plan (TTQAP) SRNL-TR-2012-00090. Preliminary method development previously conducted by Kohn et al. (2012) identified transient outflow extraction as the most promising method for characterizing the unsaturated properties of fractured porous media. While the research conducted by Kohn et al. (2012) focused on fractured media analogs such as stacked glass slides, the current task focused directly on fractured saltstone. For this task, four sample types with differing fracture geometries were considered: 1) intact saltstone, 2) intact saltstone with a single saw cut, smooth surface fracture, 3) micro-fractured saltstone (induced by oven drying), and 4) micro-fractured saltstone with a single, fully-penetrating, rough-surface fracture. Each sample type was tested initially for saturated hydraulic conductivity following method ASTM D 5084 using a flexible wall permeameter. Samples were subsequently tested using the transient outflow extraction method to determine cumulative outflow as a function of time and applied pressure. Of the four sample types tested, two yielded datasets suitable for analysis (sample types 3 and 4). The intact saltstone sample (sample type 1) did not yield any measureable outflow over the pressure range of the outflow test (0-1000 cm H{sub 2}O). This was expected because the estimated air entry pressure for intact saltstone is on the order of 100,000 cm H{sub 2}O (Dixon et al., 2009). The intact saltstone sample with a single saw cut smooth surface fracture (sample type 2) did not produce useable data because the fracture completely drained at less than 10 cm H{sub 2}O applied pressure. The cumulative outflow data from sample types 3 and 4 were analyzed using an inverse solution of the Richard’s equation for water flow in variably saturated porous media. This technique was implemented using the computer code Hydrus-1D (Šim?nek et al., 2008) and the resulting output included the van Genuchten-Mualem water retention and relative permeability parameters and predicted saturated hydraulic conductivity (Van Genuchten, 1980; Van Genuchten et al., 1991). Estimations of relative permeability and saturated conductivity are possible because the transient response of the sample to pressure changes is recorded during the multi-step outflow extraction test. Characteristic curves were developed for sample types 3 and 4 based on the results of the transient outflow method and compared to that of intact saltstone previously reported by Dixon et al. (2009). The overall results of this study indicate that the outflow extraction method is suitable for measuring the hydraulic properties of micro-fractured porous media. The resulting cumulative outflow data can be analyzed using the computer code Hydrus-1D to generate the van Genuchten curve fitting parameters that adequately describe fracture drainage. The resulting characteristic curves are consistent with blended characteristic curves that combine the behaviors of low pressure drainage associated with fracture flow with high pressure drainage from the bulk saltstone matrix.

  6. Predicting the spatial extent of injection-induced zones of enhanced permeability at the Northwest Geysers EGS Demonstration Project

    E-Print Network [OSTI]

    Rutqvist, J.

    2010-01-01T23:59:59.000Z

    are drawn into the fractured reservoir rock under vacuum.equivalent fractured rock permeability in the reservoir is

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

    E-Print Network [OSTI]

    Lolon, Elyezer P.

    2006-04-12T23:59:59.000Z

    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...

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

    E-Print Network [OSTI]

    Lolon, Elyezer P.

    2006-04-12T23:59:59.000Z

    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...

  9. The Role of Geochemistry and Stress on Fracture Development and Proppant Behavior in EGS Reservoirs

    Broader source: Energy.gov [DOE]

    Project objective: Develop Improved Methods For Maintaining Permeable Fracture Volumes In EGS Reservoirs.

  10. Interaction between Injection Points during Hydraulic Fracturing Kjetil M. D. Hals1,

    E-Print Network [OSTI]

    Santos, Juan

    fluid to create fracture networks in rock layers with low permeabilities. A fracking fluid is injected

  11. Method for directional hydraulic fracturing

    DOE Patents [OSTI]

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

    1994-01-01T23:59:59.000Z

    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.

  12. Geothermal Permeability Enhancement - Final Report

    SciTech Connect (OSTI)

    Joe Beall; Mark Walters

    2009-06-30T23:59:59.000Z

    The overall objective is to apply known permeability enhancement techniques to reduce the number of wells needed and demonstrate the applicability of the techniques to other undeveloped or under-developed fields. The Enhanced Geothermal System (EGS) concept presented in this project enhances energy extraction from reduced permeability zones in the super-heated, vapor-dominated Aidlin Field of the The Geysers geothermal reservoir. Numerous geothermal reservoirs worldwide, over a wide temperature range, contain zones of low permeability which limit the development potential and the efficient recovery of heat from these reservoirs. Low permeability results from poorly connected fractures or the lack of fractures. The Enhanced Geothermal System concept presented here expands these technologies by applying and evaluating them in a systematic, integrated program.

  13. A Global Model for Fracture Falloff Analysis

    E-Print Network [OSTI]

    Marongiu-Porcu, Matteo

    2014-10-29T23:59:59.000Z

    The reservoir permeability is an essential input for the optimum design of modern hydraulic fracture treatments, which are undeniably the crucial technology involved in the development of tight and/or unconventional gas reservoirs. The fracture...

  14. Hydrocarbon anomaly in soil gas as near-surface expressions of upflows and outflows in geothermal systems

    SciTech Connect (OSTI)

    Ong, H.L.; Higashihara, M.; Klusman, R.W.; Voorhees, K.J.; Pudjianto, R.; Ong, J

    1996-01-24T23:59:59.000Z

    A variety of hydrocarbons, C1 - C12, have been found in volcanic gases (fumarolic) and in geothermal waters and gases. The hydrocarbons are thought to have come from products of pyrolysis of kerogen in sedimentary rocks or they could be fed into the geothermal system by the recharging waters which may contain dissolved hydrocarbons or hydrocarbons extracted by the waters from the rocks. In the hot geothermal zone, 300°+ C, many of these hydrocarbons are in their critical state. It is thought that they move upwards due to buoyancy and flux up with the upflowing geothermal fluids in the upflow zones together with the magmatic gases. Permeability which could be provided by faults, fissures, mini and micro fractures are thought to provide pathways for the upward flux. A sensitive technique (Petrex) utilizing passive integrative adsorption of the hydrocarbons in soil gas on activated charcoal followed by desorption and analysis of the hydrocarbons by direct introduction mass spectrometry allows mapping of the anomalous areas. Surveys for geothermal resources conducted in Japan and in Indonesia show that the hydrocarbon anomaly occur over known fields and over areas strongly suspected of geothermal potential. The hydrocarbons found and identified were n-paraffins (C7-C9) and aromatics (C7-C8). Detection of permeable, i.e. active or open faults, parts of older faults which have been reactivated, e.g. by younger intersecting faults, and the area surrounding these faulted and permeable region is possible. The mechanism leading to the appearance of the hydrocarbon in the soil gas over upflow zones of the geothermal reservoir is proposed. The paraffins seems to be better pathfinders for the location of upflows than the aromatics. However the aromatics may, under certain circumstances, give better indications of the direction of the outflow of the geothermal system. It is thought that an upflow zone can be defined when conditions exist where the recharging waters containing the hydrocarbons feed into the geothermal kitchen. The existence of open and active faults, fissures, mini and micro fractures allow sufficient permeability for the gases to flux up and express themselves at the surface as hydrocarbon anomaly in the soil gas. When any of the requirements is absent, i.e. in the absence of the recharging waters, hydrocarbons, temperature, or permeability, no anomaly can be expected. It assumes a dynamic convective system, i.e. recharging waters, upflow and outflow. The anomalies however can define to a certain extent, regions of geothermal upflow, buoyant transport of gases, and frequently down-gradient of cooling waters.

  15. The effect of various states of stress on the permeability of Berea sandstone

    E-Print Network [OSTI]

    Gatto, Henrietta G

    1984-01-01T23:59:59.000Z

    . . EXPERIMENTAL PROCEDURES. Rock Samples. Specimen Preparation. Triaxial Apparatus. Permeability Measurements. Data Reduction. Performance of the Tests. TEST RESULTS. Hydrostatic Stress Conditions. Triaxial Test Results; Stress vs. Permeability.... . Uniaxial Strain Data Triaxial Test Results; Stress-Strain Data. . . . . . . Observational Results. . . . . . . . . . . . . . . . . , . . . . . . . . . DISCUSSION. Whole Rock Permeability. Fracture (Pre-cut Specimen) Permeability. . . Significance...

  16. Evidence of Pressure Dependent Permeability in Long-Term Shale Gas Production and Pressure Transient Responses

    E-Print Network [OSTI]

    Vera Rosales, Fabian 1986-

    2012-12-11T23:59:59.000Z

    The current state of shale gas reservoir dynamics demands understanding long-term production, and existing models that address important parameters like fracture half-length, permeability, and stimulated shale volume assume constant permeability...

  17. Evidence of Pressure Dependent Permeability in Long-Term Shale Gas Production and Pressure Transient Responses 

    E-Print Network [OSTI]

    Vera Rosales, Fabian 1986-

    2012-12-11T23:59:59.000Z

    The current state of shale gas reservoir dynamics demands understanding long-term production, and existing models that address important parameters like fracture half-length, permeability, and stimulated shale volume assume constant permeability...

  18. Numerical Investigation of Fractured Reservoir Response to Injection/Extraction Using a Fully Coupled Displacement Discontinuity Method

    E-Print Network [OSTI]

    Lee, Byungtark

    2011-10-21T23:59:59.000Z

    In geothermal reservoirs and unconventional gas reservoirs with very low matrix permeability, fractures are the main routes of fluid flow and heat transport, so the fracture permeability change is important. In fact, reservoir development under...

  19. Fluid escape from reservoirs: implications from cold seeps, fractures and injected sands

    E-Print Network [OSTI]

    Mazzini, Adriano

    Abstract Fluid escape from reservoirs: implications from cold seeps, fractures and injected sands fluids escape from hydrocarbon reservoirs through permeable networks of fractures, injected sands. Within fractures and injected sands, oxidation of chained hydrocarbons supplies bicarbonate to the co

  20. Aligned fractures modeled as boundary conditions within saturated ...

    E-Print Network [OSTI]

    2015-03-30T23:59:59.000Z

    e di Geofisica Sperimentale, OGS. SUMMARY. Fractures in a fluid-saturated poroelastic -Biot- medium are very thin, compliant and highly permeable layers.

  1. Fractured reservoirs: An analysis of coupled elastodynamic and ...

    E-Print Network [OSTI]

    Daley, T., Schoenberg, M., Rutqvist, J., and Nihei, K.

    2006-08-28T23:59:59.000Z

    Aug 28, 2006 ... pliance and fluid-permeability tensors of a layer containing closely spaced ...... Coupled thermo-hydromechanical processes of fractured media.

  2. Three dimensional geologic modeling of a fractured reservoir, Saudi Arabia

    SciTech Connect (OSTI)

    Luthy, S.T.; Grover, G.A. [Saudi Aramco, Dhahran (Saudi Arabia)

    1995-11-01T23:59:59.000Z

    A geological assessment of a large carbonate reservoir in Saudi Arabia shows that it is a Type 2 fractured reservoir in which fractures provide the essential permeability. Intercrystalline microporosity, found within the basinally deposited mudstones and wackestones, is the dominant porosity type. Near-vertical, east-west-oriented extension fractures are preferentially localized in low-to-moderate porosities associated with stylolites. Porosity/fracture density relationships, combined with the results of structural curvature mapping, yielded a 3-dimensional model of fracture density. Fracture permeability and fracture porosity distributions were generated by integrating fracture density modeling results with average fracture aperture information derived from well test data. Dramatic differences exist between matrix- and fracture-related porosity, permeability models that help explain observed production behavior within the field. These models are being used by reservoir and simulation engineers for daily reservoir management, history matching, and long-term development drilling planning.

  3. Hydraulic Fracture Monitoring: A Jonah Field Case Study

    E-Print Network [OSTI]

    Seher, T.

    2011-01-01T23:59:59.000Z

    Hydraulic fracturing involves the injection of a fluid to fracture oil and gas reservoirs, and thus increase their permeability. The process creates numerous microseismic events, which can be used to monitor subsurface ...

  4. Use of fracture surface features to improve core description and fracture interpretation in Niobrara and Gallup formations, Colorado and New Mexico

    SciTech Connect (OSTI)

    Ward, B.J.; Petrusak, R.L.; Kulander, B.R. (Amoco Production Co. Research, Tulsa, OK (USA))

    1989-09-01T23:59:59.000Z

    The Niobrara formation in the Denver basin and the Gallup formation in the eastern San Juan Basin are very fine-grained, low-permeability reservoirs. Natural fracturing provides essential reservoir permeability. When natural and induced fractures are correctly identified in core, understanding of key fractured reservoir characteristics such as fracture spacing, fracture intensity, and fracture size improves greatly. For example, the Gallup has a significant amount of non-mineralized natural fractures which are generally difficult to identify in core as natural. If these fractures are misidentified as induced, fracture intensity may be underestimated and fracture spacing may be overestimated. Diagnostic fracture surface features are very well developed in the Gallup and Niobrara. Proper identification of induced fractures and nonmineralized natural fractures is done by examining these fracture surface features under oblique illumination. The Niobrara cores that were examined provide excellent examples of induced fractures. These cores have predominately mineral-filled and slickened natural fractures. Fracture surface features on the non-mineralized fractures positively identify these fractures as induced and demonstrate that nonmineralized natural fractures are a minor component of the reservoir. The Gallup cores provide excellent examples of the diagnostic surface features of natural fractures. Fractured intervals up to 20 ft long have been recovered in Gallup core. Multiple individual fractures which comprise the larger fractured intervals are identified using fracture surface morphology. This type of detailed fracture description improves evaluations of fractured reservoir quality in the Gallup formation.

  5. Metallicity and Quasar Outflows

    E-Print Network [OSTI]

    Wang, Huiyuan; Yuan, Weimin; Wang, Tinggui

    2012-01-01T23:59:59.000Z

    Correlations are investigated of the outflow strength of quasars, as measured by the blueshift and asymmetry index (BAI) of the CIV line (Wang et al. 2011), with intensities and ratios of broad emission lines, based on composite quasar spectra built from the Sloan Digital Sky Survey. We find that most of the line ratios of other ions to CIV prominently increases with BAI. These behaviors can be well understood in the context of increasing metallicity with BAI. The strength of dominant coolant, CIV line, decreases and weak collisionally excited lines increase with gas metallicity as a result of the competition between different line coolants. Using SiIV+OIV]/CIV as an indicator of gas metallicity, we present, for the first time, a strong correlation between the metallicitiy and the outflow strength of quasars over a wide range of 1.7 to 6.9 times solar abundance. Our result implies that the metallicity plays an important role in the formation of quasar outflows, likely via affecting outflow acceleration. This ...

  6. Anisotropic Outflows and IGM Enrichment

    E-Print Network [OSTI]

    Hugo Martel; Matthew M. Pieri; Cedric Grenon

    2006-11-17T23:59:59.000Z

    We have designed an analytical model for the evolution of anisotropic galactic outflows. These outflows follow the path of least resistance, and thus travel preferentially into low-density regions, away from cosmological structures where galaxies form. We show that anisotropic outflows can significantly enrich low-density systems with metals.

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

    E-Print Network [OSTI]

    Marpaung, Fivman

    2008-10-10T23:59:59.000Z

    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... different or special methods for completion, stimulation, and/or production techniques to retrieve the resource. Natural gas from coal or coal bed methane, tight gas sands, shale gas, and gas hydrates are all examples of unconventional gas reservoirs...

  8. Characterization of natural fractures in Mesaverde core from the multiwell experiment

    SciTech Connect (OSTI)

    Finley, S.J.; Lorenz, J.C.

    1988-09-01T23:59:59.000Z

    Natural fractures dominate the permeability of tight sandstone reservoirs in the Mesaverde Formation of the Piceance Creek Basin, north-western Colorado. Roughly 1900 natural fractures, detected in 4200 ft of Mesaverde core from the US Department of Energy's Multiwell Experiment (MWX), have been differentiated into 10 different fracture types on the basis of fracture morphology, inclination, the presence of slickensides, the presence of dickite mineralization and/or host lithology. Approximately 75% of the MWX core fractures are dewatering planes in mudstone and are probably unimportant to reservoir permeability. The remaining 25% of the MWX core fractures include 275 mostly calcite-mineralized, vertical extension fractures, 61 irregular, dickite-mineralized extension fractures, 27 mostly calcite-mineralized, horizontal extension fractures, and 90 slickensided, occasionally mineralized shear fractures. These extension and shear fractures are all potentially important to reservoir permeability and consequently productivity. 13 refs., 61 figs., 2 tabs.

  9. A Triple-Porosity Model for Fractured Horizontal Wells

    E-Print Network [OSTI]

    Alahmadi, Hasan Ali H.

    2010-10-12T23:59:59.000Z

    . The model consists of three contiguous porous media: the matrix, less permeable micro-fractures and more permeable macro-fractures. Only the macro-fractures produce to the well while they are fed by the micro-fractures only. Consequently, the matrix feeds... the micro-fractures only. Therefore, the flow is sequential from one medium to the other. Four sub-models are derived based on the interporosity flow assumption between adjacent media, i.e., pseudosteady state or transient flow assumption. These are fully...

  10. Estimating Major and Minor Natural Fracture Patterns in Gas

    E-Print Network [OSTI]

    Mohaghegh, Shahab

    Estimating Major and Minor Natural Fracture Patterns in Gas Shales Using Production Data Razi Identification of infill drilling locations has been challenging with mixed results in gas shales. Natural fractures are the main source of permeability in gas shales. Natural fracture patterns in shale has a random

  11. The Effect of Proppant Size and Concentration on Hydraulic Fracture Conductivity in Shale Reservoirs 

    E-Print Network [OSTI]

    Kamenov, Anton

    2013-04-11T23:59:59.000Z

    Hydraulic fracture conductivity in ultra-low permeability shale reservoirs is directly related to well productivity. The main goal of hydraulic fracturing in shale formations is to create a network of conductive pathways in the rock which increase...

  12. The Effect of Proppant Size and Concentration on Hydraulic Fracture Conductivity in Shale Reservoirs

    E-Print Network [OSTI]

    Kamenov, Anton

    2013-04-11T23:59:59.000Z

    Hydraulic fracture conductivity in ultra-low permeability shale reservoirs is directly related to well productivity. The main goal of hydraulic fracturing in shale formations is to create a network of conductive pathways in the rock which increase...

  13. FRACTURING FLUID CHARACTERIZATION FACILITY

    SciTech Connect (OSTI)

    Subhash Shah

    2000-08-01T23:59:59.000Z

    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.

  14. Slator Ranch fracture optimization study

    SciTech Connect (OSTI)

    Ventura, J.L.

    1985-07-01T23:59:59.000Z

    The Las Ovejas (Lobo) field in Zapata County, TX, is being developed actively. The field was discovered on Tenneco Oil EandP's Slator Ranch lease with the successful completion of the Sanchez-O'Brien Vaquillas Ranch Well 1. Tenneco operates all of the 17,712-acre (71 678 X 10/sup 3/-m/sup 2/) lease (with the exception of a 320-acre (1295 X 10/sup 3/-m/sup 2/) tract assigned to the Vaquillas Ranch Well 1) and has successfully completed five wells in the Lobo field subsequent to the discovery well. The Lobo interval in the Slator Ranch area is a tight gas sand, and all these wells require fracture stimulation. Because a successful fracture is essential for a good Lobo completion and because hydraulic fracturing represents a significant portion of the completed well cost, it is important to optimize this phase of the completion. The purpose of this study was to determine the following for Slator Ranch Lobo completions: an optimum fracture length as a function of permeability; whether wells should be tailed-in with bauxite, or fractured with all bauxite or sand (if an optimum tail-in does exist, to determine the optimum tail-in for a fixed fracture length as a function of permeability); the drainage area and abandonment pressure for Slator Ranch Well 2; the effect of compression on reserves; and closure pressure as a function of time and distance along the fracture for Slator Ranch Well 2.

  15. 2006 GeoX Conference, pages 1 to 6 Characterisation of hydraulic fractures in

    E-Print Network [OSTI]

    2006 GeoX Conference, pages 1 to 6 Characterisation of hydraulic fractures in limestones using X, France Jacques.Desrues@hmg.inpg.fr ABSTRACT: Hydraulic tension fractures were produced in porous, hydraulic fracture, permeability tensor MOTS-CLÃ?S: microtomographie, fracturation hydraulique, tenseur de

  16. Dual-porosity reservoir modeling of the fractured Hanifa reservoir, Abqaiq Field, Saudi Arabia

    SciTech Connect (OSTI)

    Luthy, S.T. [Saudi Aramco, Dhahran (Saudi Arabia)

    1996-12-31T23:59:59.000Z

    Fractures play a significant role in the transmissibility of the Hanifa reservoir at Abqaiq Field. The Hanifa is a Type 2 fractured reservoir characterized by a finely-crystalline carbonate matrix which contains most of the reservoir storage porosity, and a stylolitic fracture system which provides essential permeability. Comparisons of over 5000 fractures identified from core and borehole image data with open-hole log data showed that porosity is negatively correlated with fracture density and mechanical rock strength. From these relationships, it was possible to utilize additional wells where porosity log data was available to calculate fracture densities. These wells were used to generate matrix porosity and permeability as well as fracture density attributes in a 12-sequence, 29-layer geocellular model. The effect of structural curvature on fracture intensity in the reservoir was estimated by mapping the derivative of structural dip. Incorporation of structural curvature explained variations in well test behavior not predicted by initial estimates of fracture density from porosity alone. Resultant fracture permeabilities compared favorably with well-test derived productivity indices. Three-dimensional visualization of model attributes showed that a monotonous and low (<10 md) distribution of matrix-related permeability contrasts sharply with highly variable and relatively high (>50 md) permeabilities of the fracture system. Reliability of the geocellular model to predict fracture densities and associated permeabilities has been confirmed by subsequent drilling of high cost horizontal wells, and is being used in reservoir engineering and development drilling planning efforts.

  17. Dual-porosity reservoir modeling of the fractured Hanifa reservoir, Abqaiq Field, Saudi Arabia

    SciTech Connect (OSTI)

    Luthy, S.T. (Saudi Aramco, Dhahran (Saudi Arabia))

    1996-01-01T23:59:59.000Z

    Fractures play a significant role in the transmissibility of the Hanifa reservoir at Abqaiq Field. The Hanifa is a Type 2 fractured reservoir characterized by a finely-crystalline carbonate matrix which contains most of the reservoir storage porosity, and a stylolitic fracture system which provides essential permeability. Comparisons of over 5000 fractures identified from core and borehole image data with open-hole log data showed that porosity is negatively correlated with fracture density and mechanical rock strength. From these relationships, it was possible to utilize additional wells where porosity log data was available to calculate fracture densities. These wells were used to generate matrix porosity and permeability as well as fracture density attributes in a 12-sequence, 29-layer geocellular model. The effect of structural curvature on fracture intensity in the reservoir was estimated by mapping the derivative of structural dip. Incorporation of structural curvature explained variations in well test behavior not predicted by initial estimates of fracture density from porosity alone. Resultant fracture permeabilities compared favorably with well-test derived productivity indices. Three-dimensional visualization of model attributes showed that a monotonous and low (<10 md) distribution of matrix-related permeability contrasts sharply with highly variable and relatively high (>50 md) permeabilities of the fracture system. Reliability of the geocellular model to predict fracture densities and associated permeabilities has been confirmed by subsequent drilling of high cost horizontal wells, and is being used in reservoir engineering and development drilling planning efforts.

  18. The evaluation of waterfrac technology in low-permeability gas sands in the East Texas basin

    E-Print Network [OSTI]

    Tschirhart, Nicholas Ray

    2005-11-01T23:59:59.000Z

    operators believe that low-viscosity, low-proppant concentration fracture stimulation treatments known as ??waterfracs?? produce comparable stimulation results in low-permeability gas sands and are preferred because they are less expensive than gelled...

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

    SciTech Connect (OSTI)

    Huang, Hai; Plummer, Mitchell; Podgorney, Robert

    2013-02-01T23:59:59.000Z

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

  20. Protostellar outflow-driven turbulence

    E-Print Network [OSTI]

    Christopher D. Matzner

    2007-01-01T23:59:59.000Z

    Protostellar outflows crisscross the regions of star cluster formation, stirring turbulence and altering the evolution of the forming cluster. We model the stirring of turbulent motions by protostellar outflows, building on an observation that the scaling law of supersonic turbulence implies a momentum cascade analogous to the energy cascade in Kolmogorov turbulence. We then generalize this model to account for a diversity of outflow strengths, and for outflow collimation, both of which enhance turbulence. For a single value of its coupling coefficient the model is consistent with turbulence simulations by Li & Nakamura and, plausibly, with observations of the NGC 1333 cluster-forming region. Outflow-driven turbulence is strong enough to stall collapse in cluster-forming regions for several crossing times, relieving the mismatch between star formation and turbulent decay rates. The predicted line-width-size scaling implies radial density indices between -1 and -2 for regions supported by outflow-driven turbulence, with a tendency for steeper profiles in regions that are more massive or have higher column densities.

  1. Interaction between Injection Points during Hydraulic Fracturing

    E-Print Network [OSTI]

    Hals, Kjetil M D

    2012-01-01T23:59:59.000Z

    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.

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

    Broader source: Energy.gov [DOE]

    Determine if fracturing could be used to enhance permeability; and whether dilution of existing fluids with injected water would lower corrosivity enough to allow economic production of power.

  3. A Study of Hydraulic Fracturing Initiation in Transversely Isotropic Rocks

    E-Print Network [OSTI]

    Serajian, Vahid

    2011-10-21T23:59:59.000Z

    fractures and also can be used to develop information about in-situ rock properties using failure pressure values observed in the field. Finally, mechanical and permeability anisotropy are measured using Pulse Permeameter and triaxial tests on Pierre shale....

  4. Optimization of fractured well performance of horizontal gas wells

    E-Print Network [OSTI]

    Magalhaes, Fellipe Vieira

    2009-06-02T23:59:59.000Z

    In low-permeability gas reservoirs, horizontal wells have been used to increase the reservoir contact area, and hydraulic fracturing has been further extending the contact between wellbores and reservoirs. This thesis presents an approach...

  5. Permeability of WIPP Salt During Damage Evolution and Healing

    SciTech Connect (OSTI)

    BODNER,SOL R.; CHAN,KWAI S.; MUNSON,DARRELL E.

    1999-12-03T23:59:59.000Z

    The presence of damage in the form of microcracks can increase the permeability of salt. In this paper, an analytical formulation of the permeability of damaged rock salt is presented for both initially intact and porous conditions. The analysis shows that permeability is related to the connected (i.e., gas accessible) volumetric strain and porosity according to two different power-laws, which may be summed to give the overall behavior of a porous salt with damage. This relationship was incorporated into a constitutive model, known as the Multimechanism Deformation Coupled Fracture (MDCF) model, which has been formulated to describe the inelastic flow behavior of rock salt due to coupled creep, damage, and healing. The extended model was used to calculate the permeability of rock salt from the Waste Isolation Pilot Plant (WIPP) site under conditions where damage evolved with stress over a time period. Permeability changes resulting from both damage development under deviatoric stresses and damage healing under hydrostatic pressures were considered. The calculated results were compared against experimental data from the literature, which indicated that permeability in damaged intact WIPP salt depends on the magnitude of the gas accessible volumetric strain and not on the total volumetric strain. Consequently, the permeability of WIPP salt is significantly affected by the kinetics of crack closure, but shows little dependence on the kinetics of crack removal by sintering.

  6. Dual-porosity reservoir modeling of the fractured Hanifa reservoir, Abqaiq Field, Saudi Arabia

    SciTech Connect (OSTI)

    Luthy, S.T. [Saudi Aramco, Dhahran (Saudi Arabia)

    1995-08-01T23:59:59.000Z

    Fractures play a significant role in the transmissibility of the Hanifa reservoir at Abqaiq Field. The Hanifa is a Type 2 fractured reservoir characterized by a finely-crystalline carbonate matrix which contains most of the reservoir storage porosity, and a stylolitic fracture system which provides essential permeability. Integration of borehole imaging data with available open-hole log, core, and well-test data from horizontal and vertical wells allowed for the distribution of fracture parameters, including fracture density, aperture, porosity, and permeability throughout a geocellular model. Analysis of over 5000 fractures showed that changes in lithology, grain size, and/or bed thickness do not correlate with changes in fracture densities. Review of P- and S-wave log data showed that porosity is negatively correlated with fracture density and mechanical rock strength. From these relationships, it was possible to utilize additional wells where porosity log data was available to calculate fracture densities. These wells were used to generate matrix porosity and permeability as well as fracture density attributes in a 12-sequence, 29-layer geocellular model. Fracture permeabilities compare favorably with well-test derived productivity indices. Three-dimensional visualization of model attributes showed that a monotonous and low (<10 md) distribution of matrix- related permeability contrasts sharply with highly variable and relatively high (ER 50 md) permeabilities of the fracture system. Reliability of the geocellular model to predict fracture densities and associated permeabilities has been confirmed by subsequent drilling of high cost horizontal wells, and is being used in reservoir engineering and development drilling planning efforts.

  7. Poroelastic modeling of fracture-seismic wave interaction

    SciTech Connect (OSTI)

    Nakagawa, Seiji

    2008-08-15T23:59:59.000Z

    Rock containing a compliant, fluid-filled fracture can be viewed as one case of heterogeneous poroelastic media. When this fracture is subjected to seismic waves, a strong contrast in the elastic stiffness between the fracture itself and the background can result in enhanced grain-scale local fluid flow. Because this flow--relaxing the pressure building up within the fracture--can increase the dynamic compliance of the fracture and change energy dissipation (attenuation), the scattering of seismic waves can be enhanced. Previously, for a flat, infinite fracture, we derived poroelastic seismic boundary conditions that describe the relationship between a finite jump in the stress and displacement across a fracture, expressed as a function of the stress and displacement at the boundaries. In this paper, we use these boundary conditions to determine frequency-dependent seismic wave transmission and reflection coefficients. Fluid-filled fractures with a range of mechanical and hydraulic properties are examined. From parametric studies, we found that the hydraulic permeability of a fracture fully saturated with water has little impact on seismic wave scattering. In contrast, the seismic response of a partially water-saturated fracture and a heterogeneous fracture filled with compliant liquid (e.g., supercritical CO{sub 2}) depended on the fracture permeability.

  8. A Numerical Algorithm for Fluid Flow in 3D Naturally Fractured Porous Media

    E-Print Network [OSTI]

    Kentucky, University of

    . Such fractured reservoirs could be modeled by permitting the porosity and permeability to vary rapidly as if the reservoir has two porous structures, one for the fractures and the other for the matrix blocksA Numerical Algorithm for Fluid Flow in 3D Naturally Fractured Porous Media Seongjai Kim Abstract

  9. Department of Earth Sciences www.rhul.ac.uk/earthsciences Page 1 of 2 New methods for maximising shale permeability and minimising risk

    E-Print Network [OSTI]

    Sheldon, Nathan D.

    shale permeability and minimising risk during hydraulic fracturing Supervisor(s): Agust Gudmundsson-fracture mechanics, rock physics, and sedimentology there are three aspects of hydraulic fracturing of gas shales three relate to the composition and lamination/layering (fissility) of the shales and adjacent rocks

  10. Indirect fracture delineation in a carbonate reservoir: The Upper Jurassic Hanifa of Abqaiq field, Saudi Arabia

    SciTech Connect (OSTI)

    Bailey, D.L. (Saudi Aramco, Dhahran (Saudi Arabia))

    1991-03-01T23:59:59.000Z

    Abqaiq field is a northeast-trending anticline approximately 60 km long and 12 km wide and contains several reservoirs. The Hanifa Reservoir is approximately 100 m thick and consists of fine-grained, muddy limestone with subordinate dolomite and anhydrite. Since discovery of the Hanifa oil pool in 1947, pressure fluctuations have indicated communication with the overlying Arab-D Reservoir. Welltest permeability measurements are approximately 40 times higher than core permeability measurements of the Hanifa. This divergence of Hanifa permeability measurements combined with the indicated Arab-D communication suggests the presence of a natural fracture network. Direct observations of Hanifa cores reveal common, sub-vertical fractures with average apertures <200 microns. With limited core coverage and no oriented cores, a new technique was needed to delineate the areas affected by fractures. A technique combining indirect fracture indicators was devised for Abqaiq field and can be applied to other, similar fields. The actual flow system of the Abqaiq Hanifa is a complex interaction between matrix porosity/permeability and fracture permeability or enhanced permeability. Future development plans allow for low matrix permeability access to much of the Hanifa storage space and high fracture permeability both within the Hanifa and connecting to the Arab-D Reservoir.

  11. Design and construction of an experiment for two-phase flow in fractured porous media

    SciTech Connect (OSTI)

    Ayala, R.E.G.; Aziz, K.

    1993-08-01T23:59:59.000Z

    In numerical reservoir simulation naturally fractured reservoirs are commonly divided into matrix and fracture systems. The high permeability fractures are usually entirely responsible for flow between blocks and flow to the wells. The flow in these fractures is modeled using Darcy`s law and its extension to multiphase flow by means of relative permeabilities. The influence and measurement of fracture relative permeability for two-phase flow in fractured porous media have not been studied extensively, and the few works presented in the literature are contradictory. Experimental and numerical work on two-phase flow in fractured porous media has been initiated. An apparatus for monitoring this type of flow was designed and constructed. It consists of an artificially fractured core inside an epoxy core holder, detailed pressure and effluent monitoring, saturation measurements by means of a CT-scanner and a computerized data acquisition system. The complete apparatus was assembled and tested at conditions similar to the conditions expected for the two-phase flow experiments. Fine grid simulations of the experimental setup-were performed in order to establish experimental conditions and to study the effects of several key variables. These variables include fracture relative permeability and fracture capillary pressure. The numerical computations show that the flow is dominated by capillary imbibition, and that fracture relative permeabilities have only a minor influence. High oil recoveries without water production are achieved due to effective water imbibition from the fracture to the matrix. When imbibition is absent, fracture relative permeabilities affect the flow behavior at early production times.

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

    SciTech Connect (OSTI)

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

    2004-03-15T23:59:59.000Z

    Modeling fracture-matrix interaction within a complex multiple phase flow system is a key issue for fractured reservoir simulation. Commonly used mathematical models for dealing with such interactions employ a dual- or multiple-continuum concept, in which fractures and matrix are represented as overlapping, different, but interconnected continua, described by parallel sets of conservation equations. The conventional single-point upstream weighting scheme, in which the fracture relative permeability is used to represent the counterpart at the fracture-matrix interface, is the most common scheme by which to estimate flow mobility for fracture-matrix flow terms. However, such a scheme has a serious flaw, which may lead to unphysical solutions or significant numerical errors. To overcome the limitation of the conventional upstream weighting scheme, this paper presents a physically based modeling approach for estimating physically correct relative permeability in calculating multiphase flow between fractures and the matrix, using continuity of capillary pressure at the fracture-matrix interface. The proposed approach has been implemented into two multiphase reservoir simulators and verified using analytical solutions and laboratory experimental data. The new method is demonstrated to be accurate, numerically efficient, and easy to implement in dual- or multiple-continuum models.

  13. Hydraulic Fracturing (Vermont)

    Broader source: Energy.gov [DOE]

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

  14. Enthalpy transients in fractured two-phase geothermal systems

    SciTech Connect (OSTI)

    Lippmann, M.J.; Bodvarsson, G.S.; Gaulke, S.W.

    1985-03-01T23:59:59.000Z

    Numerical modeling techniques are used to study the changes in flowing enthalpy of fluids produced from a well completed in a fractured two-phase geothermal reservoir. Complex interactions between different fracture and porous matrix parameters control the enthalpy transients. The results show that the flowing enthalpy is most sensitive to the characteristics of the relative permeability curves, the magnitude of the matrix permeability and the effective fracture porosity. Other parameters such as the thermal conductivity and fracture spacing also significantly affect the flowing enthalpy. In spite of the complex phenomena associated with enthalpy transients in fractured two-phase systems, it is possible to infer useful information about the producing geothermal reservoirs from field data. 15 refs., 13 figs., 2 tabs.

  15. Laboratory investigation of crushed salt consolidation and fracture healing

    SciTech Connect (OSTI)

    Not Available

    1987-01-01T23:59:59.000Z

    A laboratory test program was conducted to investigate the consolidation behavior of crushed salt and fracture healing in natural and artificial salt. Crushed salt is proposed for use as backfill in a nuclear waste repository in salt. Artificial block salt is proposed for use in sealing a repository. Four consolidation tests were conducted in a hydrostatic pressure vessel at a maximum pressure of 2500 psi (17.2 MPa) and at room temperature. Three 1-month tests were conducted on salt obtained from the Waste Isolation Pilot Plant and one 2-month test was conducted on salt from Avery Island. Permeability was obtained using argon and either a steady-state or transient method. Initial porosities ranged from 0.26 to 0.36 and initial permeabilities from 2000 to 50,000 md. Final porosities and permeabilities ranged from 0.05 to 0.19 and from <10/sup -5/ md to 110 md, respectively. The lowest final porosity (0.05) and permeability (<10/sup -5/ md) were obtained in a 1-month test in which 2.3% moisture was added to the salt at the beginning of the test. The consolidation rate was much more rapid than in any of the dry salt tests. The fracture healing program included 20 permeability tests conducted on fractured and unfractured samples. The tests were conducted in a Hoek cell at hydrostatic pressures up to 3000 psi (20.6 MPa) with durations up to 8 days. For the natural rock salt tested, permeability was strongly dependent on confining pressure and time. The effect of confining pressure was much weaker in the artificial salt. In most cases the combined effects of time and pressure were to reduce the permeability of fractured samples to the same order of magnitude (or less) as the permeability measured prior to fracturing.

  16. Advanced hydraulic fracturing methods to create in situ reactive barriers

    SciTech Connect (OSTI)

    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

    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.

  17. Outflow Driven Turbulence in Molecular Clouds

    E-Print Network [OSTI]

    Jonathan J. Carroll; Adam Frank; Eric G. Blackman; Andrew J. Cunningham; Alice C. Quillen

    2008-05-30T23:59:59.000Z

    In this paper we explore the relationship between protostellar outflows and turbulence in molecular clouds. Using 3-D numerical simulations we focus on the hydrodynamics of multiple outflows interacting within a parsec scale volume. We explore the extent to which transient outflows injecting directed energy and momentum into a sub-volume of a molecular cloud can be converted into random turbulent motions. We show that turbulence can readily be sustained by these interactions and show that it is possible to broadly characterize an effective driving scale of the outflows. We compare the velocity spectrum obtained in our studies to that of isotropically forced hydrodynamic turbulence finding that in outflow driven turbulence a power law is indeed achieved. However we find a steeper spectrum (beta ~ 3) is obtained in outflow driven turbulence models than in isotropically forced simulations (beta ~ 2). We discuss possible physical mechanisms responsible for these results as well and their implications for turbulence in molecular clouds where outflows will act in concert with other processes such as gravitational collapse.

  18. Accretion and plasma outflow from dissipationless discs

    E-Print Network [OSTI]

    Sergei Bogovalov; Stanislav Kelner

    2008-09-02T23:59:59.000Z

    We consider an extreme case of disc accretion onto a gravitating centre when the viscosity in the disc is negligible. The angular momentum and the rotational energy of the accreted matter is carried out by a magnetized wind outflowing from the disc. The outflow of matter from the disc occurs due to the Blandford & Payne(1982) centrifugal mechanism. The disc is assumed to be cold. Accretion and outflow are connected by the conservation of the energy, mass and the angular momentum. The basic properties of the outflow, angular momentum flux and energy flux per particle in the wind, do not depend on the details of the structure of the accretion disc. In the case of selfsimilar accretion/outflow, the dependence of the rate of accretion $\\dot M$ in the disc depends on the disc radius $r$ on the law $\\dot M \\sim r^{{1\\over2(\\alpha^2-1)}}$, where $\\alpha$ is a dimensionless Alfvenic radius. In the case of $\\alpha \\gg 1$, the accretion in the disc is provided by very weak matter outflow from the disc and the outflow predominantly occurs from the very central part of the disc. The solution obtained in the work provides mechanism which transforms the gravitational energy of the accreted matter into the energy of the outflowing wind with efficiency close to 100%. The final velocity can essentially exceed Kepler velocity at the site of the wind launch. This mechanism allows us to understand the nature of the astrophysical objects with low luminosity discs and energetic jet-like outflows.

  19. A PKN Hydraulic Fracture Model Study and Formation Permeability Determination

    E-Print Network [OSTI]

    Xiang, Jing

    2012-02-14T23:59:59.000Z

    . Two different approaches to fluid leak-off are considered, which are the classical Carter's leak-off theory with a constant leak-off coefficient, and Pressure-dependent leak-off theory. Existence of poroelastic effect in the reservoir is also...

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

    Open Energy Info (EERE)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page onYou are now leaving Energy.gov You are now leaving Energy.gov You are beingZealand Jump to:Ezfeedflag JumpID-f < RAPID‎ | RoadmapRenewableGeothermal Field | Open Energy

  1. Hydraulic fracturing-1

    SciTech Connect (OSTI)

    Not Available

    1990-01-01T23:59:59.000Z

    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.

  2. Permeable Pavements, Green Roofs, and Cisterns

    E-Print Network [OSTI]

    Hunt, William F.

    Permeable Pavements, Green Roofs, and Cisterns Stormwater Treatment Practices for Low site planning and engineer- pavements, green roofs, and cisterns, are ing to reduce or prevent cooperating. #12;Permeable Pavements What are they? Permeable pavements provide alternatives to standard

  3. Bipolar Outflows and the Evolution of Stars

    E-Print Network [OSTI]

    Adam Frank

    1998-05-20T23:59:59.000Z

    Hypersonic bipolar outflows are a ubiquitous phenomena associated with both young and highly evolved stars. Observations of Planetary Nebulae, the nebulae surrounding Luminous Blue Variables such as $\\eta$ Carinae, Wolf Rayet bubbles, the circumstellar environment of SN 1987A and Young Stellar Objects all revealed high velocity outflows with a wide range of shapes. In this paper I review the current state of our theoretical understanding of these outflows. Beginning with Planetary Nebulae considerable progress has been made in understanding bipolar outflows as the result of stellar winds interacting with the circumstellar environment. In what has been called the "Generalized Wind Blown Bubble" (GWBB) scenario, a fast tenuous wind from the central star expands into a ambient medium with an aspherical (toroidal) density distribution. Inertial gradients due to the gaseous torus quickly lead to an expanding prolate or bipolar shell of swept-up gas bounded by strong shock waves. Numerical simulations of the GWBB scenario show a surprisingly rich variety of gasdynamical behavior, allowing models to recover many of the observed properties of stellar bipolar outflows including the development of collimated supersonic jets. In this paper we review the physics behind the GWBB scenario in detail and consider its strengths and weakness. Alternative models involving MHD processes are also examined. Applications of these models to each of the principle classes of stellar bipolar outflow (YSO, PNe, LBV, SN87A) are then reviewed. Outstanding issues in the study of bipolar outflows are considered as are those questions which arise when the outflows are viewed as a single class of phenomena occuring across the HR diagram.

  4. Numerical Investigation of Interaction Between Hydraulic Fractures and Natural Fractures

    E-Print Network [OSTI]

    Xue, Wenxu

    2011-02-22T23:59:59.000Z

    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...

  5. Gas permeability of carbon aerogels

    SciTech Connect (OSTI)

    Kong, F.; LeMay, J.D.; Hulsey, S.S.; Alviso, C.T.; Pekala, R.W. (Chemistry and Materials Science Department, Lawrence Livermore National Laboratory, Livermore, California 94550 (United States))

    1993-12-01T23:59:59.000Z

    Carbon aerogels are synthesized via the aqueous polycondensation of resorcinol with formaldehyde, followed by supercritical drying and subsequent pyrolysis at 1050 [degree]C. As a result of their interconnected porosity, ultrafine cell/pore size, and high surface area, carbon aerogels have many potential applications such as supercapacitors, battery electrodes, catalyst supports, and gas filters. The performance of carbon aerogels in the latter two applications depends on the permeability or gas flow conductance in these materials. By measuring the pressure differential across a thin specimen and the nitrogen gas flow rate in the viscous regime, the permeability of carbon aerogels was calculated from equations based upon Darcy's law. Our measurements show that carbon aerogels have permeabilities on the order of 10[sup [minus]12] to 10[sup [minus]10] cm[sup 2] over the density range from 0.05--0.44 g/cm[sup 3]. Like many other aerogel properties, the permeability of carbon aerogels follows a power law relationship with density, reflecting differences in the average mesopore size. Comparing the results from this study with the permeability of silica aerogels reported by other workers, we found that the permeability of aerogels is governed by a simple universal flow equation. This paper discusses the relationship between permeability, pore size, and density in carbon aerogels.

  6. In situ permeability modification using gelled polymer systems. Annual report, April 11, 1997--April 10, 1998

    SciTech Connect (OSTI)

    Green, D.W.; Willhite, G.P.; McCool, C.S.; Heppert, J.A.; Vossoughi, S.; Michnick, M.J.

    1998-09-01T23:59:59.000Z

    Results from a research program on the application of gelled polymer technology for in situ permeability modification are presented in this report. The objective of this technology when used with displacement processes such as waterflooding is to reduce the permeability in fractures and/or high permeability matrix zones to improve volumetric sweep efficiency of the displacement process. In production wells, the objective is to reduce water influx. The research program focused on five areas: Gel treatment in fractured systems; Gel treatment in carbonate rocks; In-depth placement of gels; Gel systems for application in carbon dioxide flooding; and Gel treatment in production wells. The research program is primarily an experimental program directed toward improving the understanding of gelled polymer systems and how these systems can be used to increase oil recovery from petroleum reservoirs. A summary of progress for research conducted in the second 12 month period of a 28 month program is described.

  7. In situ permeability modification using gelled polymer systems. Topical report, June 10, 1996--April 10, 1997

    SciTech Connect (OSTI)

    Green, D.W.; Willhite, G.P.; McCool, C.S.; Heppert, J.A.; Vossoughi, S.

    1997-10-01T23:59:59.000Z

    Results from a research program on the application of gelled polymer technology for in situ permeability modification are presented in this report. The objective of this technology when used with displacement processes such as waterflooding is to reduce the permeability in fractures and/or high permeability matrix zones to improve volumetric sweep efficiency of the displacement process. In production wells, the objective is to reduce water influx. The research program is focused on five areas: gel treatment in fractured systems; gel treatment in carbonate rocks; in-depth placement of gels; gel systems for application in carbon dioxide flooding; and gel treatment in production wells. The research program is primarily an experimental program directed at improving the understanding of gelled polymer systems and how these systems can be used to increase oil recovery from petroleum reservoirs. A summary of progress for research conducted in the first 10 months of a 28 month program is described in the following sections.

  8. Effects of stress-dependent permeability on methane production from deep coal seams

    SciTech Connect (OSTI)

    McKee, C.R.; Bell, G.J.; Bumb, A.C.

    1984-05-01T23:59:59.000Z

    Methane resources are frequently associated with deeply buried coal seams which are also saturated with water; therefore, knowledge of their hydrologic properties is essential. As the formation pressure is lowered during dewatering, permeability may decline by one to two orders of magnitude. Theoretical relationships have been developed which fit laboratory data well for porosity and permeability as a function of effective stress. It was discovered that for practical purposes permeability is a function only of effective stress and the ratio of initial fracture porosity to matrix compressibility (fracture closure pressure). An approximate analytical solution for well testing has been obtained using the model developed. A new method for pump test analysis is then proposed.

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

    SciTech Connect (OSTI)

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

    1997-08-01T23:59:59.000Z

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

  10. Identification and quantification of fracture behavior through reservoir simulation

    SciTech Connect (OSTI)

    Cline, S. [Univ. of Oklahoma, Oklahoma City, OK (United States)]|[Hefner Corporation, Oklahoma City, OK (United States)

    1995-08-01T23:59:59.000Z

    This study demonstrated the use of reservoir simulation as a tool for quantifying and describing the relative significance of fracture and matrix flow units to overall reservoir storage capacity and transmissibility in a field development example. A high matrix porosity Pennsylvanian age sandstone oil reservoir, that is currently undergoing the early stages of secondary recovery by waterflood, was studied. Unexpected early water breakthrough indicated the presence of a high directional permeability fracture system superimposed on the high porosity matrix system. To further understand the reservoir behavior, improve field performance and to quantify the relative contributions of fracture and matrix units to permeability and storage capacity, a reservoir simulation and characterization project was initiated. Well test, well log, tracer and geologic data were integrated into the simulation project. The integrated study indicated that the fractures exhibited high directional permeability but low storage capacity relative to the matrix portion of the reservoir. Although fractures heavily influenced overall fluid flow behavior, they did not contain large storage capacity. The system had a low calculated fracture intensity index. Reservoir simulation enabled the quantification of the relative importance of the two flow systems which in turn had a large impact on total reserves estimates and production forecasting. Simulation results indicated a need to realign injector and producer patterns which improved production rates and ultimate recovery.

  11. Changes in seal capacity of fractured claystone caprocks induced by dissolved and gaseous CO2 seepage

    E-Print Network [OSTI]

    Luquot, Linda

    reactivate pre-existing weaknesses inherited from reservoir production periods and create new fracturesChanges in seal capacity of fractured claystone caprocks induced by dissolved and gaseous CO2 underground storage when residual CO2 gas reaches the reservoir top due to buoyancy. Permeability changes

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

    SciTech Connect (OSTI)

    Ahmad Ghassemi

    2003-06-30T23:59:59.000Z

    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.

  13. Neo-tectonic fracturing after emplacement of quaternary granitic pluton in the Kakkonda geothermal field, Japan

    SciTech Connect (OSTI)

    Doi, N.; Kato, O. [JMC Goethermal Eng. Co., Ltd., Iwate-ken (Japan); Kanisawa, S.; Ishikawa, K. [Tohoku Univ., Sendai (Japan)

    1995-12-31T23:59:59.000Z

    The fracture which occurs in the Kakkonda geothermal system was formed by neo-tectonic stress after the emplacement of the neo-granite (Quaternary Kakkonda Granite) at middle Pleistocene to recent. The characteristic contrast in permeability at ca.1.5 km is strongly controlled by the contact metamorphic zone, especially cordierite and higher grade metamorphic zones, in which the high temperature (320{degrees}C<) and low permeable deep reservoir was created. The five geothermal wells 2.5-3.0 km deep have clarified that a microearthquake zone below -1.0 km shows high permeability especially at the margin of the Kakkonda Granite, and low permeability outside of a microearthquake zone. The Kakkonda Granite is a composite pluton which has very few fractures inside of it. Thus, neo-tectonic fracturing has developed in the non-metamorphosed Tertiary formations and the margin of the Kakkonda Granite.

  14. Measurement and analysis of fractures in vertical, slant, and horizontal core, with examples from the Mesaverde formation

    SciTech Connect (OSTI)

    Lorenz, J.C. (Sandia National Labs., Albuquerque, NM (United States)); Hill, R.E. (CER Corp., Las Vegas, NV (United States))

    1991-01-01T23:59:59.000Z

    Optimum analysis of natural fracture characteristics and distributions in reservoirs requires conscientious supervision of coring operations, on-site core processing, careful layout and marketing of the core, and detailed measurement of fracture characteristics. Natural fractures provide information on the in situ permeability system, and coring-induced fractures provide data on the in situ stresses. Fracture data derived from vertical core should include fracture height, type and location of fracture terminations with respect to lithologic heterogeneity, fracture planatary and roughness, and distribution with depth. Fractures in core from either a vertical or a deviated well will yield information on dip, dip azimuth, strike, mineralization, and the orientation of fractures relative to the in situ stresses. Only measurements of fractures in core from a deviated/horizontal well will provide estimates of fracture spacing and porosity. These data can be graphed and cross-plotted to yield semi-quantitative fracture characteristics for reservoir models. Data on the orientations of fractures relative to each other in unoriented core can be nearly as useful as the absolute orientations of fractures. A deviated pilot hole is recommended for fracture assessment prior to a drilling horizontal production well because it significantly enhances the chances of fracture intersection, and therefore of fracture characterization. 35 refs., 20 figs., 2 tabs.

  15. Characterization and fluid flow simulation of naturally fractured Frontier sandstone, Green River Basin, Wyoming

    SciTech Connect (OSTI)

    Harstad, H. [New Mexico Tech, Socorro, NM (United States); Teufel, L.W.; Lorenz, J.C.; Brown, S.R. [Sandia National Labs., Albuquerque, NM (United States). Geomechanics Dept.

    1996-08-01T23:59:59.000Z

    Significant gas reserves are present in low-permeability sandstones of the Frontier Formation in the greater Green River Basin, Wyoming. Successful exploitation of these reservoirs requires an understanding of the characteristics and fluid-flow response of the regional natural fracture system that controls reservoir productivity. Fracture characteristics were obtained from outcrop studies of Frontier sandstones at locations in the basin. The fracture data were combined with matrix permeability data to compute an anisotropic horizontal permeability tensor (magnitude and direction) corresponding to an equivalent reservoir system in the subsurface using a computational model developed by Oda (1985). This analysis shows that the maximum and minimum horizontal permeability and flow capacity are controlled by fracture intensity and decrease with increasing bed thickness. However, storage capacity is controlled by matrix porosity and increases linearly with increasing bed thickness. The relationship between bed thickness and the calculated fluid-flow properties was used in a reservoir simulation study of vertical, hydraulically-fractured and horizontal wells and horizontal wells of different lengths in analogous naturally fractured gas reservoirs. The simulation results show that flow capacity dominates early time production, while storage capacity dominates pressure support over time for vertical wells. For horizontal wells drilled perpendicular to the maximum permeability direction a high target production rate can be maintained over a longer time and have higher cumulative production than vertical wells. Longer horizontal wells are required for the same cumulative production with decreasing bed thickness.

  16. Permeability extraction: A sonic log inversion

    SciTech Connect (OSTI)

    Akbar, N.; Kim, J.J. [Saudi Aramco, Dhahran (Saudi Arabia)

    1994-12-31T23:59:59.000Z

    In this paper the authors provide the missing important link between permeability and acoustic velocities by generating a permeability-dependent synthetic sonic log in a carbonate reservoir. The computations are based on Akbar`s theory that relates wave velocity to frequency, rock properties (e.g., lithology, permeability, and porosity), and fluid saturation and properties (viscosity, density, and compressibility). An inverted analytical expression of the theory is used to extract permeability from sonic velocity. The synthetic sonic and the computed permeability are compared with the observed sonic log and with plug permeability, respectively. The results demonstrate, as predicted by theory, that permeability can be related directly to acoustic velocities.

  17. Transient pressure behavior of multiple-fractured gas wells

    E-Print Network [OSTI]

    Choo, Yew Kai

    1985-01-01T23:59:59.000Z

    -theta" coordinates will be developed. This simulator will then be employed to study the tr ansient pressure behavior of low-permeability gas wells with multiple finite-conductivity fractures. This thesis follows the form and style of the Journal of Petr oleum...

  18. The lifecycle of powerful AGN outflows

    E-Print Network [OSTI]

    Christian R. Kaiser; Philip N. Best

    2006-11-07T23:59:59.000Z

    During the course of this conference, much evidence was presented that points to an intimate connection between the energetic outflows driven by AGN and the energy budget and quite possibly also the evolution of their gaseous environments. However, it is still not clear if and how the AGN activity is triggered by the cooling gas, how long the activity lasts for and how these effects give rise to the observed distribution of morphologies of the outflows. In this contribution we concentrate on the high radio luminosity end of the AGN population. While most of the heating of the environmental gas may be due to less luminous and energetic outflows, these more powerful objects have a very profound influence on their surroundings. We will describe a simple model for powerful radio galaxies and radio-loud quasars that explains the dichotomy of their large-scale radio morphologies as well as their radio luminosity function.

  19. The lifecycle of powerful AGN outflows

    E-Print Network [OSTI]

    Kaiser, C R; Kaiser, Christian R.; Best, Philip N.

    2006-01-01T23:59:59.000Z

    During the course of this conference, much evidence was presented that points to an intimate connection between the energetic outflows driven by AGN and the energy budget and quite possibly also the evolution of their gaseous environments. However, it is still not clear if and how the AGN activity is triggered by the cooling gas, how long the activity lasts for and how these effects give rise to the observed distribution of morphologies of the outflows. In this contribution we concentrate on the high radio luminosity end of the AGN population. While most of the heating of the environmental gas may be due to less luminous and energetic outflows, these more powerful objects have a very profound influence on their surroundings. We will describe a simple model for powerful radio galaxies and radio-loud quasars that explains the dichotomy of their large-scale radio morphologies as well as their radio luminosity function.

  20. Multi-Site Application of the Geomechanical Approach for Natural Fracture Exploration

    SciTech Connect (OSTI)

    R. L. Billingsley; V. Kuuskraa

    2006-03-31T23:59:59.000Z

    In order to predict the nature and distribution of natural fracturing, Advanced Resources Inc. (ARI) incorporated concepts of rock mechanics, geologic history, and local geology into a geomechanical approach for natural fracture prediction within mildly deformed, tight (low-permeability) gas reservoirs. Under the auspices of this project, ARI utilized and refined this approach in tight gas reservoir characterization and exploratory activities in three basins: the Piceance, Wind River and the Anadarko. The primary focus of this report is the knowledge gained on natural fractural prediction along with practical applications for enhancing gas recovery and commerciality. Of importance to tight formation gas production are two broad categories of natural fractures: (1) shear related natural fractures and (2) extensional (opening mode) natural fractures. While arising from different origins this natural fracture type differentiation based on morphology is sometimes inter related. Predicting fracture distribution successfully is largely a function of collecting and understanding the available relevant data in conjunction with a methodology appropriate to the fracture origin. Initially ARI envisioned the geomechanical approach to natural fracture prediction as the use of elastic rock mechanics methods to project the nature and distribution of natural fracturing within mildly deformed, tight (low permeability) gas reservoirs. Technical issues and inconsistencies during the project prompted re-evaluation of these initial assumptions. ARI's philosophy for the geomechanical tools was one of heuristic development through field site testing and iterative enhancements to make it a better tool. The technology and underlying concepts were refined considerably during the course of the project. As with any new tool, there was a substantial learning curve. Through a heuristic approach, addressing these discoveries with additional software and concepts resulted in a stronger set of geomechanical tools. Thus, the outcome of this project is a set of predictive tools with broad applicability across low permeability gas basins where natural fractures play an important role in reservoir permeability. Potential uses for these learnings and tools range from rank exploration to field-development portfolio management. Early incorporation of the permeability development concepts presented here can improve basin assessment and direct focus to the high potential areas within basins. Insight into production variability inherent in tight naturally fractured reservoirs leads to improved wellbore evaluation and reduces the incidence of premature exits from high potential plays. A significant conclusion of this project is that natural fractures, while often an important, overlooked aspect of reservoir geology, represent only one aspect of the overall reservoir fabric. A balanced perspective encompassing all aspects of reservoir geology will have the greatest impact on exploration and development in the low permeability gas setting.

  1. Simulating infiltration tests in fractured basalt at the Box Canyon Site, Idaho

    SciTech Connect (OSTI)

    Unger, Andre J.A.; Faybishenko, Boris; Bodvarsson, Gudmundur S.; Simmons, Ardyth M.

    2003-04-01T23:59:59.000Z

    The results of a series of ponded infiltration tests in variably saturated fractured basalt at Box Canyon, Idaho, were used to build confidence in conceptual and numerical modeling approaches used to simulate infiltration in fractured rock. Specifically, we constructed a dual-permeability model using TOUGH2 to represent both the matrix and fracture continua of the upper basalt flow at the Box Canyon site. A consistent set of hydrogeological parameters was obtained by calibrating the model to infiltration front arrival times in the fracture continuum as inferred from bromide samples collected from fracture/borehole intersections observed during the infiltrating tests. These parameters included the permeability of the fracture and matrix continua, the interfacial area between the fracture and matrix continua, and the porosity of the fracture continuum. To calibrate the model, we multiplied the fracture-matrix interfacial area by a factor between 0.1 and 0.01 to reduce imbibition of water from the fracture continuum into the matrix continuum during the infiltration tests. Furthermore, the porosity of the fracture continuum, as calculated using the fracture aperture inferred from pneumatic-test permeabilities, was increased by a factor of 50 yielding porosity values for the upper basalt flow in the range of 0.01 to 0.02. The fracture-continuum porosity was a highly sensitive parameter controlling the arrival times of the simulated infiltration fronts. Porosity values are consistent with those determined during the Large-Scale Aquifer Pumping and Infiltration Test at the Idaho National Engineering and Environmental Laboratory.

  2. Fracture Properties From Seismic Scattering

    E-Print Network [OSTI]

    Burns, Daniel R.

    2007-01-01T23:59:59.000Z

    Fractures scatter seismic energy and this energy can be analyzed to provide information about fracture

  3. Seismic characterization of fractures

    E-Print Network [OSTI]

    JM Carcione

    2014-06-07T23:59:59.000Z

    Seismic characterization of fractures. José M. Carcione, OGS, Italy. Fractured geological formations are generally represented with a stress-strain relation.

  4. Anisotropic Outflows and Enrichment of the Intergalactic Medium

    E-Print Network [OSTI]

    Matthew M. Pieri; Hugo Martel; Cedric Grenon

    2006-11-17T23:59:59.000Z

    We have developed an analytical model for the evolution of anisotropic galactic outflows. These outflows follow the path of least resistance, and thus travel preferentially into low-density regions, away from cosmological structures where galaxies form. We show that anisotropic outflows can significantly enrich low-density systems, while reducing the enrichment of overdense regions.

  5. Colloidosomes: Selectively Permeable Capsules Composed

    E-Print Network [OSTI]

    Weeks, Eric R.

    structures, which we call "col- loidosomes," are hollow, elastic shells whose permeability and elasticity can at the surface of water drops can be used to fabricate nano- or microporous capsules (1­5, 9); other fluid a flexible approach to the prep- aration of hollow, elastic capsules, with sizes ranging from micrometers

  6. Wellbore cement fracture evolution at the cement–basalt caprock interface during geologic carbon sequestration

    SciTech Connect (OSTI)

    Jung, Hun Bok; Kabilan, Senthil; Carson, James P.; Kuprat, Andrew P.; Um, Wooyong; Martin, Paul F.; Dahl, Michael E.; Kafentzis, Tyler A.; Varga, Tamas; Stephens, Sean A.; Arey, Bruce W.; Carroll, KC; Bonneville, Alain; Fernandez, Carlos A.

    2014-08-01T23:59:59.000Z

    Composite Portland cement-basalt caprock cores with fractures, as well as neat Portland cement columns, were prepared to understand the geochemical and geomechanical effects on the integrity of wellbores with defects during geologic carbon sequestration. The samples were reacted with CO2-saturated groundwater at 50 ºC and 10 MPa for 3 months under static conditions, while one cement-basalt core was subjected to mechanical stress at 2.7 MPa before the CO2 reaction. Micro-XRD and SEM-EDS data collected along the cement-basalt interface after 3-month reaction with CO2-saturated groundwater indicate that carbonation of cement matrix was extensive with the precipitation of calcite, aragonite, and vaterite, whereas the alteration of basalt caprock was minor. X-ray microtomography (XMT) provided three-dimensional (3-D) visualization of the opening and interconnection of cement fractures due to mechanical stress. Computational fluid dynamics (CFD) modeling further revealed that this stress led to the increase in fluid flow and hence permeability. After the CO2-reaction, XMT images displayed that calcium carbonate precipitation occurred extensively within the fractures in the cement matrix, but only partially along the fracture located at the cement-basalt interface. The 3-D visualization and CFD modeling also showed that the precipitation of calcium carbonate within the cement fractures after the CO2-reaction resulted in the disconnection of cement fractures and permeability decrease. The permeability calculated based on CFD modeling was in agreement with the experimentally determined permeability. This study demonstrates that XMT imaging coupled with CFD modeling represent a powerful tool to visualize and quantify fracture evolution and permeability change in geologic materials and to predict their behavior during geologic carbon sequestration or hydraulic fracturing for shale gas production and enhanced geothermal systems.

  7. Review of hydrogen isotope permeability through materials

    SciTech Connect (OSTI)

    Steward, S.A.

    1983-08-15T23:59:59.000Z

    This report is the first part of a comprehensive summary of the literature on hydrogen isotope permeability through materials that do not readily form hydrides. While we mainly focus on pure metals with low permeabilities because of their importance to tritium containment, we also give data on higher-permeability materials such as iron, nickel, steels, and glasses.

  8. STEAM-WATER RELATIVE PERMEABILITY A DISSERTATION

    E-Print Network [OSTI]

    Stanford University

    STEAM-WATER RELATIVE PERMEABILITY A DISSERTATION SUBMITTED TO THE DEPARTMENT OF PETROLEUM Laboratory. iv #12;ABSTRACT Steam-water relative permeability curves are required for mathematical models of two-phase geothermal reservoirs. In this study, drainage steam- water relative permeabilities were

  9. Porosity and permeability of Eastern Devonian gas shale

    SciTech Connect (OSTI)

    Soeder, D.J.

    1988-03-01T23:59:59.000Z

    High-precision core analysis has been performed on eight Devonian gas shale samples from the Appalachian basin. Seven of the core samples consist of the Upper Devonian Age Huron member of the Ohio shale, six of which came from wells in the Ohio River valley, and the seventh from a well in east-central Kentucky. The eight core sample consists of Middle Devonian Age Marcellus shale obtained from a well in Morgantown, WV. The core analysis was originally intended to supply accurate input data for Devonian shale numerical reservoir simulation. Unexpectedly, the work has identified a number of geological factors that influence gas production from organic-rich shales. The presence of petroleum as a mobile liquid phase in the pores of all seven Huron shale samples effectively limits the gas porosity of this formation to less than 0.2%, and gas permeability of the rock matrix is commonly less than 0.1 ..mu..d at reservoir stress. The Marcellus shale core, on the other hand, was free of a mobile liquid phase and had a measured gas porosity of approximately 10%, and a surprisingly high permeability of 20 ..mu..d. Gas permeability of the Marcellus was highly stress-dependent, however; doubling the net confining stress reduced the permeability by nearly 70%. The conclusion reached from this study is that the gas productivity potential of Devonian shale in the Appalachian basin is influenced by a wide range of geologic factors. Organic content, thermal maturity, natural fracture spacing, and stratigraphic relationships between gray and black shales all affect gas content and mobility. Understanding these factors can improve the exploration and development of Devonian shale gas.

  10. Implementation of the Ensemble Kalman Filter in the Characterization of Hydraulic Fractures in Shale Gas Reservoirs by Integrating Downhole Temperature Sensing Technology

    E-Print Network [OSTI]

    Moreno, Jose A

    2014-08-12T23:59:59.000Z

    -length and permeability, by assimilating data from downhole temperature sensors. The ensemble Kalman filter is implemented to assimilate DTS data and estimate fracture parameters. This inverse method is suitable for applications to non-linear assimilation problems and is...

  11. Geochemical and geomechanical effects on wellbore cement fractures

    SciTech Connect (OSTI)

    Um, Wooyong; Jung, Hun Bok; Kabilan, Senthil; Fernandez, Carlos A.; Brown, Christopher F.

    2014-01-01T23:59:59.000Z

    Experimental studies were conducted using batch reactors, X-ray microtomograpy (XMT), and computational fluid dynamics (CFD) simulation to determine changes in cement fracture surfaces, fluid flow pathways, and permeability with geochemical and geomechanical processes. Composite Portland cement-basalt caprock core with artificial fractures was prepared and reacted with CO2-saturated groundwater at 50°C and 10 MPa for 3 to 3.5 months under static conditions to understand the geochemical and geomechanical effects on the integrity of wellbores containing defects. Cement-basalt interface samples were subjected to mechanical stress at 2.7 MPa before the CO2 reaction. XMT provided three-dimensional (3-D) visualization of the opening and interconnection of cement fractures due to mechanical stress. After the CO2 reaction, XMT images revealed that calcium carbonate precipitation occurred extensively within the fractures in the cement matrix, but only partially along fractures located at the cement-basalt interface. The permeability calculated based on CFD simulation was in agreement with the experimentally measured permeability. The experimental results imply that the wellbore cement with fractures is likely to be healed during exposure to CO2-saturated groundwater under static conditions, whereas fractures along the cement-caprock interface are still likely to remain vulnerable to the leakage of CO2. CFD simulation for the flow of different fluids (CO2-saturated brine and supercritical CO2) using a pressure difference of 20 kPa and 200 kPa along ~2 cm-long cement fractures showed that a pressure gradient increase resulted in an increase of CO2 fluids flux by a factor of only ~3-9 because the friction of CO2 fluids on cement fracture surfaces increased with higher flow rate as well. At the same pressure gradient, the simulated flow rate was higher for supercritical CO2 than CO2-saturated brine by a factor of only ~2-3, because the viscosity of supercritical CO2 is much lower than that of CO2-saturated brine. The study suggests that in deep geological reservoirs the geochemical and geomechanical processes have coupled effects on the wellbore cement fracture evolution and fluid flow along the fracture surfaces.

  12. Stimuli-Responsive/Rheoreversible Hydraulic Fracturing Fluids as a Greener Alternative to Support Geothermal and Fossil Energy Production

    SciTech Connect (OSTI)

    Jung, Hun Bok; Carroll, KC; Kabilan, Senthil; Heldebrant, David J.; Hoyt, David W.; Zhong, Lirong; Varga, Tamas; Stephens, Sean A.; Adams, Lexor; Bonneville, Alain; Kuprat, Andrew P.; Fernandez, Carlos A.

    2015-01-01T23:59:59.000Z

    Cost-effective yet safe creation of high-permeability reservoirs within deep bedrock is the primary challenge for the viability of enhanced geothermal systems (EGS) and unconventional oil/gas recovery. Although fracturing fluids are commonly used for oil/gas, standard fracturing methods are not developed or proven for EGS temperatures and pressures. Furthermore, the environmental impacts of currently used fracturing methods are only recently being determined. Widespread concerns about the environmental contamination have resulted in a number of regulations for fracturing fluids advocating for greener fracturing processes. To enable EGS feasibility and lessen environmental impact of reservoir stimulation, an environmentally benign, CO2-activated, rheoreversible fracturing fluid that enhances permeability through fracturing (at significantly lower effective stress than standard fracturing fluids) due to in situ volume expansion and gel formation is investigated herein. The chemical mechanism, stability, phase-change behavior, and rheology for a novel polyallylamine (PAA)-CO2 fracturing fluid was characterized at EGS temperatures and pressures. Hydrogel is formed upon reaction with CO2 and this process is reversible (via CO2 depressurization or solubilizing with a mild acid) allowing removal from the formation and recycling, decreasing environmental impact. Rock obtained from the Coso geothermal field was fractured in laboratory experiments under various EGS temperatures and pressures with comparison to standard fracturing fluids, and the fractures were characterized with imaging, permeability measurement, and flow modeling. This novel fracturing fluid and process may vastly reduce water usage and the environmental impact of fracturing practices and effectively make EGS production and unconventional oil/gas exploitation cost-effective and cleaner.

  13. Modeling shear failure and permeability enhancement due to coupled Thermal-Hydrological-Mechanical processes in Enhanced Geothermal Reservoirs

    SciTech Connect (OSTI)

    Kelkar, Sharad [Los Alamos National Laboratory

    2011-01-01T23:59:59.000Z

    The connectivity and accessible surface area of flowing fractures, whether natural or man-made, is possibly the single most important factor, after temperature, which determines the feasibility of an Enhanced Geothermal System (EGS). Rock deformation and in-situ stress changes induced by injected fluids can lead to shear failure on preexisting fractures which can generate microseismic events, and also enhance the permeability and accessible surface area of the geothermal formation. Hence, the ability to accurately model the coupled thermal-hydrologic-mechanical (THM) processes in fractured geological formations is critical in effective EGS reservoir development and management strategies. The locations of the microseismic events can serve as indicators of the zones of enhanced permeability, thus providing vital information for verification of the coupled THM models. We will describe a general purpose computational code, FEHM, developed for this purpose, that models coupled THM processes during multiphase fluid flow and transport in fractured porous media. The code incorporates several models of fracture aperture and stress behavior combined with permeability relationships. We provide field scale examples of applications to geothermal systems to demonstrate the utility of the method.

  14. Permeability enhancement using explosive techniques

    SciTech Connect (OSTI)

    Adams, T.F.; Schmidt, S.C.; Carter, W.J.

    1980-01-01T23:59:59.000Z

    In situ recovery methods for many of our hydrocarbon and mineral resources depend on the ability to create or enhance permeability in the resource bed to allow uniform and predictable flow. To meet this need, a new branch of geomechanics devoted to computer prediction of explosive rock breakage and permeability enhancement has developed. The computer is used to solve the nonlinear equations of compressible flow, with the explosive behavior and constitutive properties of the medium providing the initial/boundary conditions and material response. Once the resulting computational tool has been verified and calibrated with appropriate large-scale field tests, it can be used to develop and optimize commercially useful explosive techniques for in situ resource recovery.

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

    E-Print Network [OSTI]

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

    2008-01-01T23:59:59.000Z

    of Naturally Fractured Reservoirs, Society of Petroleumresources from fractured reservoirs (e.g. , Warren and Root,Reservoir Engineering Stanford University, Stanford, California, January 28-30, 2008 SGP-TR-185 FRACTURE-FLOW-ENHANCED SOLUTE DIFFUSION INTO FRACTURED

  16. Naturally fractured tight gas reservoir detection optimization

    SciTech Connect (OSTI)

    NONE

    1999-06-01T23:59:59.000Z

    Building upon the partitioning of the Greater Green River Basin (GGRB) that was conducted last quarter, the goal of the work this quarter has been to conclude evaluation of the Stratos well and the prototypical Green River Deep partition, and perform the fill resource evaluation of the Upper Cretaceous tight gas play, with the goal of defining target areas of enhanced natural fracturing. The work plan for the quarter of November 1-December 31, 1998 comprised four tasks: (1) Evaluation of the Green River Deep partition and the Stratos well and examination of potential opportunity for expanding the use of E and P technology to low permeability, naturally fractured gas reservoirs, (2) Gas field studies, and (3) Resource analysis of the balance of the partitions.

  17. Spatial statistics for predicting flow through a rock fracture

    SciTech Connect (OSTI)

    Coakley, K.J.

    1989-03-01T23:59:59.000Z

    Fluid flow through a single rock fracture depends on the shape of the space between the upper and lower pieces of rock which define the fracture. In this thesis, the normalized flow through a fracture, i.e. the equivalent permeability of a fracture, is predicted in terms of spatial statistics computed from the arrangement of voids, i.e. open spaces, and contact areas within the fracture. Patterns of voids and contact areas, with complexity typical of experimental data, are simulated by clipping a correlated Gaussian process defined on a N by N pixel square region. The voids have constant aperture; the distance between the upper and lower surfaces which define the fracture is either zero or a constant. Local flow is assumed to be proportional to local aperture cubed times local pressure gradient. The flow through a pattern of voids and contact areas is solved using a finite-difference method. After solving for the flow through simulated 10 by 10 by 30 pixel patterns of voids and contact areas, a model to predict equivalent permeability is developed. The first model is for patterns with 80% voids where all voids have the same aperture. The equivalent permeability of a pattern is predicted in terms of spatial statistics computed from the arrangement of voids and contact areas within the pattern. Four spatial statistics are examined. The change point statistic measures how often adjacent pixel alternate from void to contact area (or vice versa ) in the rows of the patterns which are parallel to the overall flow direction. 37 refs., 66 figs., 41 tabs.

  18. Recent advances in hydraulic fracturing

    SciTech Connect (OSTI)

    Gidley, J.L.

    1989-01-01T23:59:59.000Z

    This book is a reference to the application of significant technological advances in hydraulic fracturing. It features illustrative problems to demonstrate specific applications of advanced technologies. Chapters examine pretreatment formation evaluation, rock mechanics and fracture geometry, 2D and 3D fracture-propagation models, propping agents and fracture conductivity, fracturing fluids and additives, fluid leakoff, flow behavior, proppant transport, treatment design, well completions, field implementation, fracturing-pressure analysis, postfracture formation evaluation, fracture azimuth and geometry determination, and economics of fracturing.

  19. Low-frequency fluid waves in fractures and pipes

    SciTech Connect (OSTI)

    Korneev, Valeri

    2010-09-01T23:59:59.000Z

    Low-frequency analytical solutions have been obtained for phase velocities of symmetrical fluid waves within both an infinite fracture and a pipe filled with a viscous fluid. Three different fluid wave regimes can exist in such objects, depending on the various combinations of parameters, such as fluid density, fluid viscosity, walls shear modulus, channel thickness, and frequency. Equations for velocities of all these regimes have explicit forms and are verified by comparisons with the exact solutions. The dominant role of fractures in rock permeability at field scales and the strong amplitude and frequency effects of Stoneley guided waves suggest the importance of including these wave effects into poroelastic theories.

  20. High velocity impact fracture

    E-Print Network [OSTI]

    Teng, Xiaoqing

    2005-01-01T23:59:59.000Z

    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 ...

  1. An outflow boundary condition and algorithm for incompressible two ...

    E-Print Network [OSTI]

    S. Dong

    2014-03-05T23:59:59.000Z

    Feb 22, 2014 ... [8] S. Dong, G.E. Karniadakis, C. Chryssostomidis, A robust and accurate outflow boundary condition for incompressible flow simulations on ...

  2. Neutrino-Driven Mass Loading of GRMHD Outflows

    E-Print Network [OSTI]

    Amir Levinson

    2006-10-15T23:59:59.000Z

    A GRMHD model of disk outflows with neutrino-driven mass ejection is presented. The model is used to calculate the structure of the outflow in the sub-slow magnetosonic region and the mass loading of the outflow, under conditions anticipated in the central engines of gamma-ray bursts. It is concluded that magnetic launching of ultra-relativistic polar outflows is in principle possible along low inclination field lines (with respect to the symmetry axis), provided the neutrino luminosity is sufficiently low, $L_\

  3. Occurrence Frequency of CO Outflows in Massive Protostellar Candidates

    E-Print Network [OSTI]

    Kee-Tae Kim; S. E. Kurtz

    2006-01-24T23:59:59.000Z

    We mapped 12 massive protostellar candidates in the CO J=2-1 line, which in combination with Zhang et al. (2005) completes an unbiased survey of outflows for all 48 sources with l>50^o in a sample of 101 massive protostellar candidates. We detected outflows in 10 sources, implying 88% occurrence frequency of outflows for the 48 sources. This supports the conclusion of previous studies that bipolar outflows are an integral component in the formation process of massive stars. The vast majority of the observed outflows are much more massive (>10~Mo) and energetic (>100~Mo~km/s) than outflows from low-mass protostars. They also have large mass outflow rates (>2x10^{-4}~Mo/yr), suggesting large (~1x10^{-4}~Mo/yr) accretion rates sufficient to overcome radiation pressure of the central massive protostars. We compared the frequency distribution of collimation factors of 40 massive outflows including those of this study with that of 36 low-mass outflows from the literature, and found NO significant difference between the two. All these results are consistent with the suggestion that massive stars form through accretion as do low-mass stars but with much higher accretion rates.

  4. aqueous outflow facility: Topics by E-print Network

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

    systems. Z. Paragi; I. Fejes; R. C. Vermeulen; R. T. Schilizzi; R. E. Spencer; A. M. Stirling 2002-07-03 82 Protostellar outflows with Smoothed Particle Magnetohydrodynamics...

  5. aqueous humor outflow: Topics by E-print Network

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

    systems. Z. Paragi; I. Fejes; R. C. Vermeulen; R. T. Schilizzi; R. E. Spencer; A. M. Stirling 2002-07-03 103 Protostellar outflows with Smoothed Particle Magnetohydrodynamics...

  6. The Political History of Hydraulic Fracturing’s Expansion Across the West

    E-Print Network [OSTI]

    Forbis, Robert E.

    2014-01-01T23:59:59.000Z

    Political History of Hydraulic Fracturing’s Expansion AcrossPolitical History of Hydraulic Fracturing’s Expansion Acrosss use of the hydraulic fracturing development process.

  7. Characterisation of hydraulic fractures in limestones using X-ray microtomography

    E-Print Network [OSTI]

    Renard, Francois; Desrues, Jacques; Plougonven, Erwan; Ougier-Simonin, Audrey

    2006-01-01T23:59:59.000Z

    Hydraulic tension fractures were produced in porous limestones using a specially designed hydraulic cell. The 3D geometry of the samples was imaged using X-ray computed microtomography before and after fracturation. Using these data, it was possible to estimate the permeability tensor of the core samples, extract the path of the rupture and compare it to the heterogeneities initially present in the rock.

  8. Application of computed tomography to enhanced oil recovery studies in naturally fractured reservoirs 

    E-Print Network [OSTI]

    Fineout, James Mark

    1992-01-01T23:59:59.000Z

    , they developed both a single matrix block model and a dual matrix block model with variable fracture width. These tests related imbibition theory with regard to matrix block size, permeability and fluid viscosity affects on oil recovery. They also determined... in naturally fractured reservoirs have relied upon material balance calculations to determine saturation changes. Through the use of Computed Tomography scanning, we have developed a technique not only to determine saturation changes but also positional...

  9. Statistical analysis of liquid seepage in partially saturated heterogeneous fracture systems

    SciTech Connect (OSTI)

    Liou, T.S.

    1999-12-01T23:59:59.000Z

    Field evidence suggests that water flow in unsaturated fracture systems may occur along fast preferential flow paths. However, conventional macroscale continuum approaches generally predict the downward migration of water as a spatially uniform wetting front subjected to strong inhibition into the partially saturated rock matrix. One possible cause of this discrepancy may be the spatially random geometry of the fracture surfaces, and hence, the irregular fracture aperture. Therefore, a numerical model was developed in this study to investigate the effects of geometric features of natural rock fractures on liquid seepage and solute transport in 2-D planar fractures under isothermal, partially saturated conditions. The fractures were conceptualized as 2-D heterogeneous porous media that are characterized by their spatially correlated permeability fields. A statistical simulator, which uses a simulated annealing (SA) algorithm, was employed to generate synthetic permeability fields. Hypothesized geometric features that are expected to be relevant for seepage behavior, such as spatially correlated asperity contacts, were considered in the SA algorithm. Most importantly, a new perturbation mechanism for SA was developed in order to consider specifically the spatial correlation near conditioning asperity contacts. Numerical simulations of fluid flow and solute transport were then performed in these synthetic fractures by the flow simulator TOUGH2, assuming that the effects of matrix permeability, gas phase pressure, capillary/permeability hysteresis, and molecular diffusion can be neglected. Results of flow simulation showed that liquid seepage in partially saturated fractures is characterized by localized preferential flow, along with bypassing, funneling, and localized ponding. Seepage pattern is dominated by the fraction of asperity contracts, and their shape, size, and spatial correlation. However, the correlation structure of permeability field is less important than the spatial correlation of asperity contacts. A faster breakthrough was observed in fractures subjected to higher normal stress, accompanied with a nonlinearly decreasing trend of the effective permeability. Interestingly, seepage dispersion is generally higher in fractures with intermediate fraction of asperity contacts; but it is lower for small or large fractions of asperity contacts. However, it may become higher if the ponding becomes significant. Transport simulations indicate that tracers bypass dead-end pores and travel along flow paths that have less flow resistance. Accordingly, tracer breakthrough curves generally show more spreading than breakthrough curves for water. Further analyses suggest that the log-normal time model generally fails to fit the breakthrough curves for water, but it is a good approximation for breakthrough curves for the tracer.

  10. New cement additives that eliminate cement body permeability

    SciTech Connect (OSTI)

    Talabani, S.; Hareland, G. [New Mexico Inst. of Mining and Technology, Socorro, NM (United States)

    1995-10-01T23:59:59.000Z

    An experimental investigation was carried out replacing some currently used cement additives with three new additives. The experiments performed monitored the cement slurry pressure during the setting of the cement. During the setting period of the cement, two time cycles of cement expansion and contraction are observed. This is due to the individual contribution of each component in the cement mixture. To obtain the optimum tightness of the cement, final contraction in the cycle is crucial for blockage of gas migration. In these studies optimum concentrations of the additives were obtained experimentally, where the cyclic pressure behavior of the cement was optimized and the permeability reduced for the best final cement results. The parameters investigated in this study were; change in the applied pressure on the slurry with time, the compressive strength and permeability of the set cement. The major causes of the early microfractures are the in-complete cement-water reaction, low compressive strength of the set cement, and the sudden change in the hydrostatic pressure as the cement changes its phase from liquid to a solid state. The fluid loss and free water content were measured and controlled for each sample. The results of this study is that proper amounts of X-C polymer, Anchorage clay, Ironite Sponge, and Synthetic Rubber can be used to optimize the compressive strength and eliminate both micro-fracture and micro-annulus. There are certain limits to the amount and type of Synthetic Rubber powder which cement will set and the micro-fractures are eliminated. This experimental approach can be used to eliminate gas migration through a cement design that is environmentally safe, inexpensive, and uses recyclable materials.

  11. IC5063: AGN driven outflow of warm and cold gas

    E-Print Network [OSTI]

    R. Morganti; J. Holt; L. Saripalli; T. A. Oosterloo; C. N. Tadhunter

    2007-10-05T23:59:59.000Z

    We present new ATCA 17- and 24-GHz radio images and ESO-NTT optical spectra of the radio-loud Seyfert galaxy IC5063, the first galaxy in which a fast (~ 600 km/s) outflow of neutral hydrogen was discovered. The new radio data confirm the triple radio structure with a central core and two resolved radio lobes. This implies that the previously detected fast outflow of neutral gas is occurring off-nucleus, near a radio lobe about 0.5 kpc from the core. The ionised gas shows complex kinematics in the region co-spatial with the radio emission. Broad and blueshifted (~ 500 km/s) emission is observed in the region of the radio lobe, at the same location as the blueshifted HI absorption. The velocity of the ionised outflow is similar to the one found in HI. The first order correspondence between the radio and optical properties suggests that the outflow is driven by the interaction between the radio jet and the ISM. Despite the high outflow velocities, no evidence is found for the ionisation of the gas being due to fast shocks in the region of the outflow, indicating that photoionisation from the AGN is likely to be the dominant ionisation mechanism. The outflow rate of the warm (ionised) gas is small compared to that of the cold gas. The mass outflow rate associated with the HI is in the same range as for ``mild'' starburst-driven superwinds in ULIRGs. However, in IC5063, the AGN-driven outflow appears to be limited to the inner kpc region of the galaxy. The kinetic power associated with the HI outflow is a small fraction (a few x 10^-4) of the Eddington luminosity of the galaxy but is a significant fraction (~ 0.1) of the nuclear bolometric luminosity. In IC5063, the outflows may have sufficient kinetic power to have a significant impact on the evolution of the ISM in the host galaxy.

  12. Rejuvenating Permeable Reactive Barriers by Chemical Flushing

    Broader source: Energy.gov [DOE]

    Final Report:Rejuvenating Permeable Reactive Barriers by Chemical Flushing,U.S. Environmental Protection Agency, Region 8 Support.August 2004

  13. Magma energy and geothermal permeability enhancement programs

    SciTech Connect (OSTI)

    Dunn, J.C.

    1985-01-01T23:59:59.000Z

    Accomplishments during FY85 and project plans for FY86 are described for the Magma Energy Extraction and Permeability Enhancement programs. (ACR)

  14. Simulating galactic outflows with kinetic supernova feedback

    E-Print Network [OSTI]

    Claudio Dalla Vecchia; Joop Schaye

    2008-05-07T23:59:59.000Z

    Feedback from star formation is thought to play a key role in the formation and evolution of galaxies, but its implementation in cosmological simulations is currently hampered by a lack of numerical resolution. We present and test a sub-grid recipe to model feedback from massive stars in cosmological smoothed particle hydrodynamics simulations. The energy is distributed in kinetic form among the gas particles surrounding recently formed stars. The impact of the feedback is studied using a suite of high-resolution simulations of isolated disc galaxies embedded in dark halos with total mass 10^{10} and 10^{12} Msol/h. We focus in particular on the effect of pressure forces on wind particles within the disc, which we turn off temporarily in some of our runs to mimic a recipe that has been widely used in the literature. We find that this popular recipe gives dramatically different results because (ram) pressure forces on expanding superbubbles determine both the structure of the disc and the development of large-scale outflows. Pressure forces exerted by expanding superbubbles puff up the disc, giving the dwarf galaxy an irregular morphology and creating a galactic fountain in the massive galaxy. Hydrodynamic drag within the disc results in a strong increase of the effective mass loading of the wind for the dwarf galaxy, but quenches much of the outflow in the case of the high-mass galaxy.

  15. Power spectra of outflow-driven turbulence

    E-Print Network [OSTI]

    Moraghan, Anthony; Yoon, Suk-Jin

    2015-01-01T23:59:59.000Z

    We investigate the power spectra of outflow-driven turbulence through high-resolution three-dimensional isothermal numerical simulations where the turbulence is driven locally in real-space by a simple spherical outflow model. The resulting turbulent flow saturates at an average Mach number of ~2.5 and is analysed through density and velocity power spectra, including an investigation of the evolution of the solenoidal and compressional components. We obtain a shallow density power spectrum with a slope of ~-1.2 attributed to the presence of a network of localised dense filamentary structures formed by strong shock interactions. The total velocity power spectrum slope is found to be ~-2.0, representative of Burgers shock dominated turbulence model. The density weighted velocity power spectrum slope is measured as ~-1.6, slightly less than the expected Kolmogorov scaling value (slope of -5/3) found in previous works. The discrepancy may be caused by the nature of our real space driving model and we suggest ther...

  16. Multiphase Fluid Flow in Deformable Variable-Aperture Fractures - Final Report

    SciTech Connect (OSTI)

    Detwiler, Russell

    2014-04-30T23:59:59.000Z

    Fractures provide flow paths that can potentially lead to fast migration of fluids or contaminants. A number of energy-­?related applications involve fluid injections that significantly perturb both the pressures and chemical composition of subsurface fluids. These perturbations can cause both mechanical deformation and chemical alteration of host rocks with potential for significant changes in permeability. In fractured rock subjected to coupled chemical and mechanical stresses, it can be difficult to predict the sign of permeability changes, let alone the magnitude. This project integrated experimental and computational studies to improve mechanistic understanding of these coupled processes and develop and test predictive models and monitoring techniques. The project involved three major components: (1) study of two-­?phase flow processes involving mass transfer between phases and dissolution of minerals along fracture surfaces (Detwiler et al., 2009; Detwiler, 2010); (2) study of fracture dissolution in fractures subjected to normal stresses using experimental techniques (Ameli, et al., 2013; Elkhoury et al., 2013; Elkhoury et al., 2014) and newly developed computational models (Ameli, et al., 2014); (3) evaluation of electrical resistivity tomography (ERT) as a method to detect and quantify gas leakage through a fractured caprock (Breen et al., 2012; Lochbuhler et al., 2014). The project provided support for one PhD student (Dr. Pasha Ameli; 2009-­?2013) and partially supported a post-­?doctoral scholar (Dr. Jean Elkhoury; 2010-­?2013). In addition, the project provided supplemental funding to support collaboration with Dr. Charles Carrigan at Lawrence Livermore National Laboratory in connection with (3) and supported one MS student (Stephen Breen; 2011-­?2013). Major results from each component of the project include the following: (1) Mineral dissolution in fractures occupied by two fluid phases (e.g., oil-­?water or water-­?CO{sub 2}) causes changes in local capillary forces and redistribution of fluids. These coupled processes enhance channel formation and the potential for development of fast flow paths through fractures. (2) Dissolution in fractures subjected to normal stress can result in behaviors ranging from development of dissolution channels and rapid permeability increases to fracture healing and significant permeability decreases. The timescales associated with advective transport of dissolved ions in the fracture, mineral dissolution rates, and diffusion within the adjacent porous matrix dictate the sign and magnitude of the resulting permeability changes. Furthermore, a high-­? resolution mechanistic model that couples elastic deformation of contacts and aperture-­?dependent dissolution rates predicts the range of observed behaviors reasonably well. (3) ERT has potential as a tool for monitoring gas leakage in deep formations. Using probabilistic inversion methods further enhances the results by providing uncertainty estimates of inverted parameters.

  17. Giant Molecular Outflows Powered by Protostars in L1448

    E-Print Network [OSTI]

    G. A. Wolf-Chase; M. Barsony; J. O'Linger

    2000-05-15T23:59:59.000Z

    We present sensitive, large-scale maps of the CO J=1-0 emission of the L1448 dark cloud. These maps were acquired using the On-The-Fly capability of the NRAO 12-meter telescope. CO outflow activity is seen in L1448 on parsec-scales for the first time. Careful comparison of the spatial and velocity distribution of our high-velocity CO maps with previously published optical and near-infrared images and spectra has led to the identification of six distinct CO outflows. We show the direct link between the heretofore unknown, giant, highly-collimated, protostellar molecular outflows and their previously discovered, distant optical manifestations. The outflows traced by our CO mapping generally reach the projected cloud boundaries. Integrated intensity maps over narrow velocity intervals indicate there is significant overlap of blue- and red-shifted gas, suggesting the outflows are highly inclined with respect to the line-of-sight, although the individual outflow position angles are significantly different. The velocity channel maps also show that the outflows dominate the CO line cores as well as the high-velocity wings. The magnitude of the combined flow momenta, as well as the combined kinetic energy of the flows, are sufficient to disperse the 50 solar mass NH3 cores in which the protostars are currently forming, although some question remains as to the exact processes involved in redirecting the directionality of the outflow momenta to effect the complete dispersal of the parent cloud.

  18. Bipolar molecular outflows driven by hydromagnetic protostellar winds

    E-Print Network [OSTI]

    Christopher D. Matzner; Christopher F. McKee

    1999-09-29T23:59:59.000Z

    We demonstrate that magnetically-collimated protostellar winds will sweep ambient material into thin, radiative, momentum-conserving shells whose features reproduce those commonly observed in bipolar molecular outflows. We find the typical position-velocity and mass-velocity relations to occur in outflows in a wide variety of ambient density distributions, regardless of the time histories of their driving winds.

  19. THE TEMPERATURE DEPENDENCE OF SOLAR ACTIVE REGION OUTFLOWS

    SciTech Connect (OSTI)

    Warren, Harry P.; Ugarte-Urra, Ignacio; Young, Peter R.; Stenborg, Guillermo [Space Science Division, Naval Research Laboratory, Washington, DC 20375 (United States)

    2011-01-20T23:59:59.000Z

    Spectroscopic observations with the EUV Imaging Spectrometer (EIS) on Hinode have revealed large areas of high-speed outflows at the periphery of many solar active regions. These outflows are of interest because they may connect to the heliosphere and contribute to the solar wind. In this paper, we use slit rasters from EIS in combination with narrowband slot imaging to study the temperature dependence and morphology of an outflow region and show that it is more complicated than previously thought. Outflows are observed primarily in emission lines from Fe XI to Fe XV. Observations at lower temperatures (Si VII), in contrast, show bright fan-like structures that are dominated by inflows. These data also indicate that the morphology of the outflows and the fans is different, outflows are observed in regions where there is no emission in Si VII. This suggests that the fans, which are often associated with outflows in studies involving imaging data, are not directly related to the active region outflows.

  20. Reconnection outflow generated turbulence in the solar wind

    E-Print Network [OSTI]

    Vörös, Z; Semenov, V S; Zaqarashvili, T V; Bruno, R; Khodachenko, M

    2014-01-01T23:59:59.000Z

    Petschek-type time-dependent reconnection (TDR) and quasi-stationary reconnection (QSR) models are considered to understand reconnection outflow structures and the features of the associated locally generated turbulence in the solar wind. We show that the outflow structures, such as discontinuites, Kelvin-Helmholtz (KH) unstable flux tubes or continuous space filling flows cannot be distinguished from one-point WIND measurements. In both models the reconnection outflows can generate more or less spatially extended turbulent boundary layers (TBDs). The structure of an unique extended reconnection outflow is investigated in detail. The analysis of spectral scalings and break locations show that reconnection outflows can control the local field and plasma conditions which may play in favor of one or another turbulent dissipation mechanisms with their characteristic scales and wavenumbers.

  1. Self-potential observations during hydraulic fracturing

    E-Print Network [OSTI]

    Moore, Jeffrey R.; Glaser, Steven D.

    2008-01-01T23:59:59.000Z

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

  2. Integrated seismic study of naturally fractured tight gas reservoirs. Technical progress report for the period: 7/1/93--9/31/93

    SciTech Connect (OSTI)

    Mavko, G.; Nur, A.

    1993-10-23T23:59:59.000Z

    The study area is located at the southern end of the Powder River Basin in Converse County in east-central Wyoming. It is a low permeability fractured site, with both gas and oil present. Reservoirs are highly compartmentalized due to the low permeabilities, and fractures provide the only practical paths of production. During this eighth quarter of the seismic study of this area, work continued in processing seismic data, collecting additional geological information to aid in the interpretation, and integrating regional structural information and fracture trends with observations of structure in the study area.

  3. TRACER ANALYSIS IN A FRACTURED GEO'MERMAL RESERVOIR: FIELD RESULTS FROM WAIRAKEI, NEW ZEALAND

    E-Print Network [OSTI]

    Stanford University

    TRACER ANALYSIS IN A FRACTURED GEO'MERMAL RESERVOIR: FIELD RESULTS FROM WAIRAKEI, NEW ZEALAND . . . . . . . . . . . . . . . . . . . . . . . . . . . 122 -V- #12;Chapter I INTRODUCTION Interwell tracers have been used extensively in oil reservoirs to detect reservoir heterogeneities. High permeability production zones can channel a disproportionate

  4. ADVANCED FRACTURING TECHNOLOGY FOR TIGHT GAS: AN EAST TEXAS FIELD DEMONSTRATION

    SciTech Connect (OSTI)

    Mukul M. Sharma

    2005-03-01T23:59:59.000Z

    The primary objective of this research was to improve completion and fracturing practices in gas reservoirs in marginal plays in the continental United States. The Bossier Play in East Texas, a very active tight gas play, was chosen as the site to develop and test the new strategies for completion and fracturing. Figure 1 provides a general location map for the Dowdy Ranch Field, where the wells involved in this study are located. The Bossier and other tight gas formations in the continental Unites States are marginal plays in that they become uneconomical at gas prices below $2.00 MCF. It was, therefore, imperative that completion and fracturing practices be optimized so that these gas wells remain economically attractive. The economic viability of this play is strongly dependent on the cost and effectiveness of the hydraulic fracturing used in its well completions. Water-fracs consisting of proppant pumped with un-gelled fluid is the type of stimulation used in many low permeability reservoirs in East Texas and throughout the United States. The use of low viscosity Newtonian fluids allows the creation of long narrow fractures in the reservoir, without the excessive height growth that is often seen with cross-linked fluids. These low viscosity fluids have poor proppant transport properties. Pressure transient tests run on several wells that have been water-fractured indicate a long effective fracture length with very low fracture conductivity even when large amounts of proppant are placed in the formation. A modification to the water-frac stimulation design was needed to transport proppant farther out into the fracture. This requires suspending the proppant until the fracture closes without generating excessive fracture height. A review of fracture diagnostic data collected from various wells in different areas (for conventional gel and water-fracs) suggests that effective propped lengths for the fracture treatments are sometimes significantly shorter than those predicted by fracture models. There was no accepted optimal method for conducting hydraulic fracturing in the Bossier. Each operator used a different approach. Anadarko, the most active operator in the play, had tested at least four different kinds of fracture treatments. The ability to arrive at an optimal fracturing program was constrained by the lack of adequate fracture models to simulate the fracturing treatment, and an inability to completely understand the results obtained in previous fracturing programs. This research aimed at a combined theoretical, experimental and field-testing program to improve fracturing practices in the Bossier and other tight gas plays.

  5. Slow Waves in Fractures Filled with Viscous Fluid

    SciTech Connect (OSTI)

    Korneev, Valeri

    2008-01-08T23:59:59.000Z

    Stoneley guided waves in a fluid-filled fracture generally have larger amplitudes than other waves, and therefore, their properties need to be incorporated in more realistic models. In this study, a fracture is modeled as an infinite layer of viscous fluid bounded by two elastic half-spaces with identical parameters. For small fracture thickness, I obtain a simple dispersion equation for wave-propagation velocity. This velocity is much smaller than the velocity of a fluid wave in a Biot-type solution, in which fracture walls are assumed to be rigid. At seismic prospecting frequencies and realistic fracture thicknesses, the Stoneley guided wave has wavelengths on the order of several meters and an attenuation Q factor exceeding 10, which indicates the possibility of resonance excitation in fluid-bearing rocks. The velocity and attenuation of Stoneley guided waves are distinctly different at low frequencies for water and oil. The predominant role of fractures in fluid flow at field scales is supported by permeability data showing an increase of several orders of magnitude when compared to values obtained at laboratory scales. These data suggest that Stoneley guided waves should be taken into account in theories describing seismic wave propagation in fluid-saturated rocks.

  6. State-of-the-art fracturing in the North Sea

    SciTech Connect (OSTI)

    Domelen, M.S. Van; Jacquier, R.C.; Sanders, M.W.

    1995-12-31T23:59:59.000Z

    This paper will focus on recent advances in hydraulic fracturing technology with emphasis on North Sea applications. Five generalized applications that will benefit most from advances in technology have been identified. Because North Sea oil and gas field development requires the use of platform facilities for wellhead and processing equipment, deviated and horizontal wells are often used to effectively drain the reservoirs. Many of these wells require fracture stimulation. The success rate of such wells has increased significantly in recent years as a result of the following: Researchers better understand how fractures initiate and grow; Pre-treatment diagnostic techniques have improved substantially; Engineers better understand how completion design affects well performance. With improved understanding of post-frac well performance, engineers can evaluate the feasibility of developing a reservoir through fractured, horizontal wells. In addition to a review of the advances in HPHT technology that would apply to North Sea applications, this paper will identify improvements necessary before these techniques are applied in the North Sea. Hydraulic fracturing is being used more frequently (1) in high-permeability reservoirs to improve the overall profitability of the project, and (2) as an alternative to traditional sand control applications in soft, weakly consolidated reservoirs. The effect of hydraulic fracturing operations on the North Sea environment must be recognized. The advances in fluid design and post-treatment flowback procedures that minimize these effects are discussed. 78 refs., 19 figs.

  7. Simulation of Hydraulic Fractures and their Interactions with Natural Fractures

    E-Print Network [OSTI]

    Sesetty, Varahanaresh

    2012-10-19T23:59:59.000Z

    Modeling the stimulated reservoir volume during hydraulic fracturing is important to geothermal and petroleum reservoir stimulation. The interaction between a hydraulic fracture and pre-existing natural fractures exerts significant control...

  8. Multiple-point statistical prediction on fracture networks at Yucca Mountain

    SciTech Connect (OSTI)

    Liu, X.Y; Zhang, C.Y.; Liu, Q.S.; Birkholzer, J.T.

    2009-05-01T23:59:59.000Z

    In many underground nuclear waste repository systems, such as at Yucca Mountain, water flow rate and amount of water seepage into the waste emplacement drifts are mainly determined by hydrological properties of fracture network in the surrounding rock mass. Natural fracture network system is not easy to describe, especially with respect to its connectivity which is critically important for simulating the water flow field. In this paper, we introduced a new method for fracture network description and prediction, termed multi-point-statistics (MPS). The process of the MPS method is to record multiple-point statistics concerning the connectivity patterns of a fracture network from a known fracture map, and to reproduce multiple-scale training fracture patterns in a stochastic manner, implicitly and directly. It is applied to fracture data to study flow field behavior at the Yucca Mountain waste repository system. First, the MPS method is used to create a fracture network with an original fracture training image from Yucca Mountain dataset. After we adopt a harmonic and arithmetic average method to upscale the permeability to a coarse grid, THM simulation is carried out to study near-field water flow in the surrounding waste emplacement drifts. Our study shows that connectivity or patterns of fracture networks can be grasped and reconstructed by MPS methods. In theory, it will lead to better prediction of fracture system characteristics and flow behavior. Meanwhile, we can obtain variance from flow field, which gives us a way to quantify model uncertainty even in complicated coupled THM simulations. It indicates that MPS can potentially characterize and reconstruct natural fracture networks in a fractured rock mass with advantages of quantifying connectivity of fracture system and its simulation uncertainty simultaneously.

  9. Experimental and Theoretical Investigation of Multiphase Flow in Fractured Porous media, SUPRI TR-116, Topical Report

    SciTech Connect (OSTI)

    Akin, Serhat; Castanier, Louis M.; German, Edgar Rene Rangel

    1999-08-09T23:59:59.000Z

    The fluid transfer parameters between rock matrix and fracture are not well known. Consequently, simulation of fractured reservoirs uses, in general, very crude and unproven hypotheses such as zero capillary pressure in the fracture and/or relative permeability linear with saturation. In order to improve the understanding of flow in fractured media, an experimental study was conducted and numerical simulations of the experiments were made. A laboratory flow apparatus was built to obtain data on water- air imbibition and oil-water drainage displacements in horizontal single-fractured block systems. For this purpose, two configurations have been used: a two-block system with a 1 mm spacer between the blocks, and a two-block system with no spacer. During the experiments, porosity and saturation measurements along the cores have been made utilizing an X-ray Computerized Tomography (CT) scanner. Saturation images were reconstructed in 3-D to observe matrix-fracture interactions. Differences in fluid saturations and relative permeabilities caused by changes in fracture width have also been analyzed.

  10. Hydrogen Permeability and Integrity of Hydrogen Delivery Pipelines...

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

    Permeability and Integrity of Hydrogen Delivery Pipelines Hydrogen Permeability and Integrity of Hydrogen Delivery Pipelines Project Objectives: To gain basic understanding of...

  11. Hydrogen permeability and Integrity of hydrogen transfer pipelines...

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

    permeability and Integrity of hydrogen transfer pipelines Hydrogen permeability and Integrity of hydrogen transfer pipelines Presentation by 03-Babu for the DOE Hydrogen Pipeline...

  12. Sustainability of Shear-Induced Permeability for EGS Reservoirs...

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

    Sustainability of Shear-Induced Permeability for EGS Reservoirs A Laboratory Study Sustainability of Shear-Induced Permeability for EGS Reservoirs A Laboratory Study...

  13. Field Demonstration Of Permeable Reactive Barriers To Remove

    E-Print Network [OSTI]

    Field Demonstration Of Permeable Reactive Barriers To Remove Dissolved Uranium From Groundwater-001 November 2000 FIELD DEMONSTRATION OF PERMEABLE REACTIVE BARRIERS TO REMOVE DISSOLVED URANIUM FROM

  14. Uranium(VI) Diffusion in Low-Permeability Subsurface Materials...

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

    Uranium(VI) Diffusion in Low-Permeability Subsurface Materials. Uranium(VI) Diffusion in Low-Permeability Subsurface Materials. Abstract: Uranium(VI) diffusion was investigated in...

  15. aqp1 water permeability: Topics by E-print Network

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

    RELATIVE PERMEABILITY A DISSERTATION Renewable Energy Websites Summary: STEAM-WATER RELATIVE PERMEABILITY A DISSERTATION SUBMITTED TO THE DEPARTMENT OF PETROLEUM...

  16. TEMPORAL VARIATIONS OF FRACTURE DIRECTIONS AND FRACTURE DENSITIES...

    Open Energy Info (EERE)

    OF SHEAR-WAVE SPLITTING Jump to: navigation, search OpenEI Reference LibraryAdd to library Conference Proceedings: TEMPORAL VARIATIONS OF FRACTURE DIRECTIONS AND FRACTURE...

  17. DEVELOPMENT OF RESERVOIR CHARACTERIZATION TECHNIQUES AND PRODUCTION MODELS FOR EXPLOITING NATURALLY FRACTURED RESERVOIRS

    SciTech Connect (OSTI)

    Michael L. Wiggins; Raymon L. Brown; Faruk Civan; Richard G. Hughes

    2002-12-31T23:59:59.000Z

    For many years, geoscientists and engineers have undertaken research to characterize naturally fractured reservoirs. Geoscientists have focused on understanding the process of fracturing and the subsequent measurement and description of fracture characteristics. Engineers have concentrated on the fluid flow behavior in the fracture-porous media system and the development of models to predict the hydrocarbon production from these complex systems. This research attempts to integrate these two complementary views to develop a quantitative reservoir characterization methodology and flow performance model for naturally fractured reservoirs. The research has focused on estimating naturally fractured reservoir properties from seismic data, predicting fracture characteristics from well logs, and developing a naturally fractured reservoir simulator. It is important to develop techniques that can be applied to estimate the important parameters in predicting the performance of naturally fractured reservoirs. This project proposes a method to relate seismic properties to the elastic compliance and permeability of the reservoir based upon a sugar cube model. In addition, methods are presented to use conventional well logs to estimate localized fracture information for reservoir characterization purposes. The ability to estimate fracture information from conventional well logs is very important in older wells where data are often limited. Finally, a desktop naturally fractured reservoir simulator has been developed for the purpose of predicting the performance of these complex reservoirs. The simulator incorporates vertical and horizontal wellbore models, methods to handle matrix to fracture fluid transfer, and fracture permeability tensors. This research project has developed methods to characterize and study the performance of naturally fractured reservoirs that integrate geoscience and engineering data. This is an important step in developing exploitation strategies for optimizing the recovery from naturally fractured reservoir systems. The next logical extension of this work is to apply the proposed methods to an actual field case study to provide information for verification and modification of the techniques and simulator. This report provides the details of the proposed techniques and summarizes the activities undertaken during the course of this project. Technology transfer activities were highlighted by a two-day technical conference held in Oklahoma City in June 2002. This conference attracted over 90 participants and included the presentation of seventeen technical papers from researchers throughout the United States.

  18. Correlation of hydrothermal sericite composition with permeability...

    Open Energy Info (EERE)

    zones and temperature. The wells studied intersect rhyolitic dikes and sills in the fractured granitic and dioritic basement rocks which serve as the reservoir for the...

  19. Core analysis in a low permeability sandstone reservoir: Results from the Multiwell Experiment

    SciTech Connect (OSTI)

    Sattler, A.R.

    1989-04-01T23:59:59.000Z

    Over 4100 ft (1100 ft oriented) of Mesaverde core was taken during the drilling of the three Multiwell Experiment (MWX) wells, for study in a comprehensive core analysis program. This core traversed five separate depositional environments (shoreline/marine, coastal, paludal, fluvial, and paralic), and almost every major sand in the Mesaverde at the site was sampled. This paper summarizes MWX core analysis and describes the petrophysical properties at the MWX site; reservoir parameters, including permeabilities of naturally fractured core; and mechanical rock properties including stress-related measurements. Some correlations are made between reservoir properties and mineralogy/petrology data. Comparisons are made between the properties of lenticular and blanket sandstone morphologies existing at the site. This paper provides an overview of a complete core analysis in a low-permeability sandstone reservoir. 66 refs., 17 figs. , 9 tabs.

  20. Advection-Dominated Accretion with Infall and Outflows

    E-Print Network [OSTI]

    Thomas Beckert

    2000-03-22T23:59:59.000Z

    We present self-similar solutions for advection-dominated accretion flows with radial viscous force in the presence of outflows from the accretion flow or infall. The axisymmetric flow is treated in variables integrated over polar sections and the effects of infall and outflows on the accretion flow are parametrised for possible configurations compatible with the self-similar solution. We investigate the resulting accretion flows for three different viscosity laws and derive upper limits on the viscosity parameter alpha. In addition, we find a natural connection to non-rotating and spherical accretion with turbulent viscosity, which is assumed to persist even without differential rotation. Positive Bernoulli numbers for advection-dominated accretion allow a fraction of the gas to be expelled in an outflow and the upper limit on the viscosity predicts that outflows are inevitable for equations of state close to an ideal gas.

  1. MISALIGNMENT OF MAGNETIC FIELDS AND OUTFLOWS IN PROTOSTELLAR CORES

    SciTech Connect (OSTI)

    Hull, Charles L. H.; Plambeck, Richard L.; Bower, Geoffrey C.; Heiles, Carl; Meredith Hughes, A. [Astronomy Department and Radio Astronomy Laboratory, University of California, Berkeley, CA 94720-3411 (United States); Bolatto, Alberto D.; Jameson, Katherine; Mundy, Lee; Pound, Marc W. [Astronomy Department and Laboratory for Millimeter-wave Astronomy, University of Maryland, College Park, MD 20742 (United States); Carpenter, John M.; Lamb, James W.; Pillai, Thushara [Department of Astronomy, California Institute of Technology, 1200 E. California Blvd., MC 249-17, Pasadena, CA 91125 (United States); Crutcher, Richard M.; Hakobian, Nicholas S.; Kwon, Woojin; Looney, Leslie W. [Department of Astronomy, University of Illinois at Urbana-Champaign, 1002 W Green Street, Urbana, IL 61801 (United States); Fiege, Jason D.; Franzmann, Erica [Department of Physics and Astronomy, University of Manitoba, Winnipeg, MB R3T 2N2 (Canada); Houde, Martin [Department of Physics and Astronomy, University of Western Ontario, London, ON N6A 3K7 (Canada); Matthews, Brenda C., E-mail: chat@astro.berkeley.edu [Department of Physics and Astronomy, University of Victoria, 3800 Finnerty Rd., Victoria, BC V8P 5C2 (Canada); and others

    2013-05-10T23:59:59.000Z

    We present results of {lambda}1.3 mm dust-polarization observations toward 16 nearby, low-mass protostars, mapped with {approx}2.''5 resolution at CARMA. The results show that magnetic fields in protostellar cores on scales of {approx}1000 AU are not tightly aligned with outflows from the protostars. Rather, the data are consistent with scenarios where outflows and magnetic fields are preferentially misaligned (perpendicular), or where they are randomly aligned. If one assumes that outflows emerge along the rotation axes of circumstellar disks, and that the outflows have not disrupted the fields in the surrounding material, then our results imply that the disks are not aligned with the fields in the cores from which they formed.

  2. HP-41 Calculates Dykstra-Parsons permeability

    SciTech Connect (OSTI)

    Bixler, B.

    1983-07-01T23:59:59.000Z

    A new program for the HP-41 programmable calculator has been written which will calculate the often used Dykstra-Parsons permeability variation factor, V. No longer must numerous individual permeability values be plotted on log probability paper as a first step in determining V. Input is simply these same permeability values selected at equal spacing along the interval in question. For most core analysis this spacing will be 1 ft. This program is labeled ''KVAR'' (for permeability variation) and is listed here, along with its bar code for those with optical wands. It requires only nine registers for program storage (since it uses HP built-in statistical functions) and eight registers for data storage. Also, it can be stored on one track of the standard two-track magnetic card. Data entry is terminated by entering ''O''. Lastly, it will run with or without a printer.

  3. Reservoir permeability from seismic attribute analysis

    E-Print Network [OSTI]

    Goloshubin, G.

    2008-01-01T23:59:59.000Z

    of the reservoir permeability based on seismic and log data.seismic reservoir response based on well and 3D seismic datadata analysis we suggest seismic imaging of the reservoir

  4. Ultra-fast outflows (aka UFOs) from AGNs and QSOs

    E-Print Network [OSTI]

    Cappi, M; Giustini, M

    2013-01-01T23:59:59.000Z

    During the last decade, strong observational evidence has been accumulated for the existence of massive, high velocity winds/outflows (aka Ultra Fast Outflows, UFOs) in nearby AGNs and in more distant quasars. Here we briefly review some of the most recent developments in this field and discuss the relevance of UFOs for both understanding the physics of accretion disk winds in AGNs, and for quantifying the global amount of AGN feedback on the surrounding medium.

  5. HOT ELECTROMAGNETIC OUTFLOWS. II. JET BREAKOUT

    SciTech Connect (OSTI)

    Russo, Matthew [Department of Physics, University of Toronto, 60 St. George Street, Toronto, ON M5S 1A7 (Canada); Thompson, Christopher [Canadian Institute for Theoretical Astrophysics, 60 St. George Street, Toronto, ON M5S 3H8 (Canada)

    2013-08-20T23:59:59.000Z

    We consider the interaction between radiation, matter, and a magnetic field in a compact, relativistic jet. The entrained matter accelerates outward as the jet breaks out of a star or other confining medium. In some circumstances, such as gamma-ray bursts (GRBs), the magnetization of the jet is greatly reduced by an advected radiation field while the jet is optically thick to scattering. Where magnetic flux surfaces diverge rapidly, a strong outward Lorentz force develops and radiation and matter begin to decouple. The increase in magnetization is coupled to a rapid growth in Lorentz factor. We take two approaches to this problem. The first examines the flow outside the fast magnetosonic critical surface, and calculates the flow speed and the angular distribution of the radiation field over a range of scattering depths. The second considers the flow structure on both sides of the critical surface in the optically thin regime, using a relaxation method. In both approaches, we find how the terminal Lorentz factor and radial profile of the outflow depend on the radiation intensity and optical depth at breakout. The effect of bulk Compton scattering on the radiation spectrum is calculated by a Monte Carlo method, while neglecting the effects of internal dissipation. The peak of the scattered spectrum sits near the seed peak if radiation pressure dominates the acceleration, but is pushed to a higher frequency if the Lorentz force dominates. The unscattered seed radiation can form a distinct, low-frequency component of the spectrum, especially if the magnetic Poynting flux dominates.

  6. Determination of Transport Properties From Flowing Fluid Temperature LoggingIn Unsaturated Fractured Rocks: Theory And Semi-Analytical Solution

    SciTech Connect (OSTI)

    Mukhopadhyay, Sumit; Tsang, Yvonne W.

    2008-08-01T23:59:59.000Z

    Flowing fluid temperature logging (FFTL) has been recently proposed as a method to locate flowing fractures. We argue that FFTL, backed up by data from high-precision distributed temperature sensors, can be a useful tool in locating flowing fractures and in estimating the transport properties of unsaturated fractured rocks. We have developed the theoretical background needed to analyze data from FFTL. In this paper, we present a simplified conceptualization of FFTL in unsaturated fractured rock, and develop a semianalytical solution for spatial and temporal variations of pressure and temperature inside a borehole in response to an applied perturbation (pumping of air from the borehole). We compare the semi-analytical solution with predictions from the TOUGH2 numerical simulator. Based on the semi-analytical solution, we propose a method to estimate the permeability of the fracture continuum surrounding the borehole. Using this proposed method, we estimated the effective fracture continuum permeability of the unsaturated rock hosting the Drift Scale Test (DST) at Yucca Mountain, Nevada. Our estimate compares well with previous independent estimates for fracture permeability of the DST host rock. The conceptual model of FFTL presented in this paper is based on the assumptions of single-phase flow, convection-only heat transfer, and negligible change in system state of the rock formation. In a sequel paper [Mukhopadhyay et al., 2008], we extend the conceptual model to evaluate some of these assumptions. We also perform inverse modeling of FFTL data to estimate, in addition to permeability, other transport parameters (such as porosity and thermal conductivity) of unsaturated fractured rocks.

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

    SciTech Connect (OSTI)

    Mukul Sharma; Kyle Friehauf

    2009-12-31T23:59:59.000Z

    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.

  8. Dominant Nuclear Outflow Driving Mechanisms in Powerful Radio Galaxies

    E-Print Network [OSTI]

    Dan Batcheldor; Clive Tadhunter; Joanna Holt; Raffaella Morganti; Christopher P. O'Dea; David J. Axon; Anton Koekemoer

    2007-02-20T23:59:59.000Z

    In order to identify the dominant nuclear outflow mechanisms in Active Galactic Nuclei, we have undertaken deep, high resolution observations of two compact radio sources (PKS 1549-79 and PKS 1345+12) with the Advanced Camera for Surveys (ACS) aboard the Hubble Space Telescope. Not only are these targets known to have powerful emission line outflows, but they also contain all the potential drivers for the outflows: relativistic jets, quasar nuclei and starbursts. ACS allows the compact nature (nuclear position angles of both the optical emission line and radio data. There is no evidence for bi-conical emission line features on the large-scale and there is a divergance in the relative position angles of the optical and radio structure. This enables us to exclude starburst driven outflows. However, we are unable to clearly distinguish between radiative AGN wind driven outflows and outflows powered by relativistic radio jets. The small scale bi-conical features, indicative of such mechanisms could be below the resolution limit of ACS, especially if aligned close to the line of sight. In addition, there may be offsets between the radio and optical nuclei induced by heavy dust obscuration, nebular continuum or scattered light from the AGN.

  9. Continuous time random walk analysis of solute transport in fractured porous media

    SciTech Connect (OSTI)

    Cortis, Andrea; Cortis, Andrea; Birkholzer, Jens

    2008-06-01T23:59:59.000Z

    The objective of this work is to discuss solute transport phenomena in fractured porous media, where the macroscopic transport of contaminants in the highly permeable interconnected fractures can be strongly affected by solute exchange with the porous rock matrix. We are interested in a wide range of rock types, with matrix hydraulic conductivities varying from almost impermeable (e.g., granites) to somewhat permeable (e.g., porous sandstones). In the first case, molecular diffusion is the only transport process causing the transfer of contaminants between the fractures and the matrix blocks. In the second case, additional solute transfer occurs as a result of a combination of advective and dispersive transport mechanisms, with considerable impact on the macroscopic transport behavior. We start our study by conducting numerical tracer experiments employing a discrete (microscopic) representation of fractures and matrix. Using the discrete simulations as a surrogate for the 'correct' transport behavior, we then evaluate the accuracy of macroscopic (continuum) approaches in comparison with the discrete results. However, instead of using dual-continuum models, which are quite often used to account for this type of heterogeneity, we develop a macroscopic model based on the Continuous Time Random Walk (CTRW) framework, which characterizes the interaction between the fractured and porous rock domains by using a probability distribution function of residence times. A parametric study of how CTRW parameters evolve is presented, describing transport as a function of the hydraulic conductivity ratio between fractured and porous domains.

  10. OPTIMIZATION OF INFILL DRILLING IN NATURALLY-FRACTURED TIGHT-GAS RESERVOIRS

    SciTech Connect (OSTI)

    Lawrence W. Teufel; Her-Yuan Chen; Thomas W. Engler; Bruce Hart

    2004-05-01T23:59:59.000Z

    A major goal of industry and the U.S. Department of Energy (DOE) fossil energy program is to increase gas reserves in tight-gas reservoirs. Infill drilling and hydraulic fracture stimulation in these reservoirs are important reservoir management strategies to increase production and reserves. Phase II of this DOE/cooperative industry project focused on optimization of infill drilling and evaluation of hydraulic fracturing in naturally-fractured tight-gas reservoirs. The cooperative project involved multidisciplinary reservoir characterization and simulation studies to determine infill well potential in the Mesaverde and Dakota sandstone formations at selected areas in the San Juan Basin of northwestern New Mexico. This work used the methodology and approach developed in Phase I. Integrated reservoir description and hydraulic fracture treatment analyses were also conducted in the Pecos Slope Abo tight-gas reservoir in southeastern New Mexico and the Lewis Shale in the San Juan Basin. This study has demonstrated a methodology to (1) describe reservoir heterogeneities and natural fracture systems, (2) determine reservoir permeability and permeability anisotropy, (3) define the elliptical drainage area and recoverable gas for existing wells, (4) determine the optimal location and number of new in-fill wells to maximize economic recovery, (5) forecast the increase in total cumulative gas production from infill drilling, and (6) evaluate hydraulic fracture simulation treatments and their impact on well drainage area and infill well potential. Industry partners during the course of this five-year project included BP, Burlington Resources, ConocoPhillips, and Williams.

  11. RADIATION TRANSPORT FOR EXPLOSIVE OUTFLOWS: OPACITY REGROUPING

    SciTech Connect (OSTI)

    Wollaeger, Ryan T. [Department of Nuclear Engineering and Engineering Physics, University of Wisconsin, Madison 1500 Engineering Drive, 410 ERB, Madison, WI 53706 (United States); Van Rossum, Daniel R., E-mail: wollaeger@wisc.edu, E-mail: daan@flash.uchicago.edu [Flash Center for Computational Science, Department of Astronomy and Astrophysics, University of Chicago, Chicago, IL 60637 (United States)

    2014-10-01T23:59:59.000Z

    Implicit Monte Carlo (IMC) and Discrete Diffusion Monte Carlo (DDMC) are methods used to stochastically solve the radiative transport and diffusion equations, respectively. These methods combine into a hybrid transport-diffusion method we refer to as IMC-DDMC. We explore a multigroup IMC-DDMC scheme that in DDMC, combines frequency groups with sufficient optical thickness. We term this procedure ''opacity regrouping''. Opacity regrouping has previously been applied to IMC-DDMC calculations for problems in which the dependence of the opacity on frequency is monotonic. We generalize opacity regrouping to non-contiguous groups and implement this in SuperNu, a code designed to do radiation transport in high-velocity outflows with non-monotonic opacities. We find that regrouping of non-contiguous opacity groups generally improves the speed of IMC-DDMC radiation transport. We present an asymptotic analysis that informs the nature of the Doppler shift in DDMC groups and summarize the derivation of the Gentile-Fleck factor for modified IMC-DDMC. We test SuperNu using numerical experiments including a quasi-manufactured analytic solution, a simple 10 group problem, and the W7 problem for Type Ia supernovae. We find that opacity regrouping is necessary to make our IMC-DDMC implementation feasible for the W7 problem and possibly Type Ia supernova simulations in general. We compare the bolometric light curves and spectra produced by the SuperNu and PHOENIX radiation transport codes for the W7 problem. The overall shape of the bolometric light curves are in good agreement, as are the spectra and their evolution with time. However, for the numerical specifications we considered, we find that the peak luminosity of the light curve calculated using SuperNu is ?10% less than that calculated using PHOENIX.

  12. Transport in Cement:Transport in Cement: Relating Permeability and PoreRelating Permeability and Pore

    E-Print Network [OSTI]

    Petta, Jason

    Transport in Cement:Transport in Cement: Relating Permeability and PoreRelating Permeability, 2004 #12;OutlineOutline Cement Manufacturing and StructureCement Manufacturing and Structure ofofCalcinated in rotaryin rotary kiln at 1500 C for 30kiln at 1500 C for 30-- 40 minutes40 minutes Produces Cement

  13. Fracture and Healing of Rock Salt Related to Salt Caverns

    SciTech Connect (OSTI)

    Chan, K.S.; Fossum, A.F.; Munson, D.E.

    1999-03-01T23:59:59.000Z

    In recent years, serious investigations of potential extension of the useful life of older caverns or of the use of abandoned caverns for waste disposal have been of interest to the technical community. All of the potential applications depend upon understanding the reamer in which older caverns and sealing systems can fail. Such an understanding will require a more detailed knowledge of the fracture of salt than has been necessary to date. Fortunately, the knowledge of the fracture and healing of salt has made significant advances in the last decade, and is in a position to yield meaningful insights to older cavern behavior. In particular, micromechanical mechanisms of fracture and the concept of a fracture mechanism map have been essential guides, as has the utilization of continuum damage mechanics. The Multimechanism Deformation Coupled Fracture (MDCF) model, which is summarized extensively in this work was developed specifically to treat both the creep and fracture of salt, and was later extended to incorporate the fracture healing process known to occur in rock salt. Fracture in salt is based on the formation and evolution of microfractures, which may take the form of wing tip cracks, either in the body or the boundary of the grain. This type of crack deforms under shear to produce a strain, and furthermore, the opening of the wing cracks produce volume strain or dilatancy. In the presence of a confining pressure, microcrack formation may be suppressed, as is often the case for triaxial compression tests or natural underground stress situations. However, if the confining pressure is insufficient to suppress fracture, then the fractures will evolve with time to give the characteristic tertiary creep response. Two first order kinetics processes, closure of cracks and healing of cracks, control the healing process. Significantly, volume strain produced by microfractures may lead to changes in the permeability of the salt, which can become a major concern in cavern sealing and operation. The MDCF model is used in three simulations of field experiments in which indirect measures were obtained of the generation of damage. The results of the simulations help to verify the model and suggest that the model captures the correct fracture behavior of rock salt. The model is used in this work to estimate the generation and location of damage around a cylindrical storage cavern. The results are interesting because stress conditions around the cylindrical cavern do not lead to large amounts of damage. Moreover, the damage is such that general failure can not readily occur, nor does the extent of the damage suggest possible increased permeation when the surrounding salt is impermeable.

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

    SciTech Connect (OSTI)

    Gary Mavko

    2000-10-01T23:59:59.000Z

    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.

  15. Suspensions in hydraulic fracturing

    SciTech Connect (OSTI)

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

    1996-12-31T23:59:59.000Z

    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.

  16. Naturally fractured tight gas reservoir detection optimization. Final report

    SciTech Connect (OSTI)

    NONE

    1997-11-19T23:59:59.000Z

    This DOE-funded research into seismic detection of natural fractures is one of six projects within the DOE`s Detection and Analysis of Naturally Fractured Gas Reservoirs Program, a multidisciplinary research initiative to develop technology for prediction, detection, and mapping of naturally fractured gas reservoirs. The demonstration of successful seismic techniques to locate subsurface zones of high fracture density and to guide drilling orientation for enhanced fracture permeability will enable better returns on investments in the development of the vast gas reserves held in tight formations beneath the Rocky Mountains. The seismic techniques used in this project were designed to capture the azimuthal anisotropy within the seismic response. This seismic anisotropy is the result of the symmetry in the rock fabric created by aligned fractures and/or unequal horizontal stresses. These results may be compared and related to other lines of evidence to provide cross-validation. The authors undertook investigations along the following lines: Characterization of the seismic anisotropy in three-dimensional, P-wave seismic data; Characterization of the seismic anisotropy in a nine-component (P- and S-sources, three-component receivers) vertical seismic profile; Characterization of the seismic anisotropy in three-dimensional, P-to-S converted wave seismic data (P-wave source, three-component receivers); and Description of geological and reservoir-engineering data that corroborate the anisotropy: natural fractures observed at the target level and at the surface, estimation of the maximum horizontal stress in situ, and examination of the flow characteristics of the reservoir.

  17. Outflows and Jets from Collapsing Magnetized Cloud Cores

    E-Print Network [OSTI]

    Robi Banerjee; Ralph E. Pudritz

    2005-12-13T23:59:59.000Z

    Star formation is usually accompanied by outflow phenomena. There is strong evidence that these outflows and jets are launched from the protostellar disk by magneto-rotational processes. Here, we report on our three dimensional, adaptive mesh, magneto-hydrodynamic simulations of collapsing, rotating, magnetized Bonnor-Ebert-Spheres whose properties are taken directly from observations. In contrast to the pure hydro case where no outflows are seen, our present simulations show an outflow from the protodisk surface at ~ AU and a jet at ~ 0.07 AU after a strong toroidal magnetic field build up. The large scale outflow, which extends up to ~ AU at the end of our simulation, is driven by toroidal magnetic pressure (spring), whereas the jet is powered by magneto-centrifugal force (fling). At the final stage of our simulation these winds are still confined within two respective shock fronts. Furthermore, we find that the jet-wind and the disk-anchored magnetic field extracts a considerable amount of angular momentum from the protostellar disk. The initial spin of our cloud core was chosen high enough to produce a binary system. We indeed find a close binary system (separation ~ 3 R_sol) which results from the fragmentation of an earlier formed ring structure. The magnetic field strength in these protostars reaches ~ 3 kG and becomes about 3 G at 1 AU from the center in agreement with recent observational results.

  18. Self-potential observations during hydraulic fracturing

    E-Print Network [OSTI]

    Moore, J R; Glaser, Steven D

    2007-01-01T23:59:59.000Z

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

  19. Can a fractured caprock self-heal?

    E-Print Network [OSTI]

    Elkhoury, JE; Elkhoury, JE; Detwiler, RL; Ameli, P

    2015-01-01T23:59:59.000Z

    characterization of fractured reservoirs. J. Geophys. Eng.fractured carbonates caused by flow of CO 2 -rich brine under reservoirreservoirs. We present results from two experiments in fractured

  20. Pressure grouting of fractured basalt flows

    SciTech Connect (OSTI)

    Shaw, P.; Weidner, J.; Phillips, S.; Alexander, J.

    1996-04-01T23:59:59.000Z

    This report describes a field trial of pressure grouting in basalt and the results of subsequent coring and permeability measurement activities. The objective was to show that the hydraulic conductivity of fractured basalt bedrock can be significantly reduced by pressure injection of cementitious materials. The effectiveness of the pressure grout procedure was evaluated by measuring the change in the hydraulic conductivity of the bedrock. The extent of grout penetration was established by analyzing postgrout injection drilling chips for the presence of a tracer in the grout and also by examining cores of the treated basalt. Downhole radar mapping was used to establish major lava flow patterns and follow water movement during a surface infiltration test. A site called Box Canyon, which is located northwest of the INEL, was chosen for this study due to the similarity of this surface outcrop geology to that of the underlying bedrock fracture system found at the Radioactive Waste Management Complex. This study showed that hydraulic conductivity of basalt can be reduced through pressure grouting of cementitious material.

  1. Coordinated studies in support of hydraulic fracturing of coalbed methane. Annual report, November 1991-December 1992

    SciTech Connect (OSTI)

    Not Available

    1993-04-01T23:59:59.000Z

    The purpose of the work is to characterize common and potential fracturing fluids in terms of coal-fluid interactions to identify reasons for less than satisfactory performance and to ultimately devise alternative fluids and treatment procedures to optimize production following hydraulic fracturing. The laboratory data reported herein has proven helpful in designing improved hydraulic fracturing treatments and remedial treatments in the Black Warrior Basin. Acid inhibitors, scale inhibitors, additives to improve coal relative permeability to gas, and non-damaging polymer systems for hydraulic fracturing have been screened in coal damage tests. The optimum conditions for creating field-like foams in the laboratory have been explored. Tests have been run to identify minimum polymer and surfactant concentrations for applications of foam in coal. The roll of 100 mesh sand in controlling leakoff and impairing conductivity in coal has been investigated.

  2. Magnetic Reconnection with Asymmetry in the Outflow Direction

    E-Print Network [OSTI]

    Murphy, N A; Cassak, P A

    2009-01-01T23:59:59.000Z

    Magnetic reconnection with asymmetry in the outflow direction occurs in the Earth's magnetotail, coronal mass ejections, flux cancellation events, astrophysical disks, spheromak merging experiments, and elsewhere in nature and the laboratory. A control volume analysis is performed for the case of steady antiparallel magnetic reconnection with asymmetric downstream pressure, which is used to derive scaling relations for the outflow velocity from each side of the current sheet and the reconnection rate. Simple relationships for outflow velocity are presented for the incompressible case and the case of symmetric downstream pressure but asymmetric downstream density. Asymmetry alone is not found to greatly affect the reconnection rate. The flow stagnation point and magnetic field null do not coincide in a steady state unless the pressure gradient is negligible at the flow stagnation point.

  3. CORONAL MASS EJECTION INDUCED OUTFLOWS OBSERVED WITH HINODE/EIS

    SciTech Connect (OSTI)

    Jin, M.; Ding, M. D.; Chen, P. F.; Fang, C. [Department of Astronomy, Nanjing University, Nanjing 210093 (China); Imada, S. [National Astronomical Observatory of Japan, 2-21-1 Osawa, Mitaka, Tokyo 181-8588 (Japan)], E-mail: dmd@nju.edu.cn, E-mail: shinsuke.imada@nao.ac.jp

    2009-09-01T23:59:59.000Z

    We investigate the outflows associated with two halo coronal mass ejections (CMEs) that occurred on 2006 December 13 and 14 in NOAA 10930, using the Hinode/EIS observations. Each CME was accompanied by an EIT wave and coronal dimmings. Dopplergrams in the dimming regions are obtained from the spectra of seven EIS lines. The results show that strong outflows are visible in the dimming regions during the CME eruption at different heights from the lower transition region to the corona. It is found that the velocity is positively correlated with the photospheric magnetic field, as well as the magnitude of the dimming. We estimate the mass loss based on height-dependent EUV dimmings and find it to be smaller than the CME mass derived from white-light observations. The mass difference is attributed partly to the uncertain atmospheric model, and partly to the transition region outflows, which refill the coronal dimmings.

  4. SCATTERED EMISSION FROM z {approx} 1 GALACTIC OUTFLOWS

    SciTech Connect (OSTI)

    Martin, Crystal L.; Pancoast, Anna [Department of Physics, University of California, Santa Barbara, CA 93106 (United States); Shapley, Alice E.; Kornei, Katherine A. [Department of Physics and Astronomy, University of California, Los Angeles, CA 90025 (United States); Coil, Alison L. [Center for Astrophysics and Space Sciences, Department of Physics, University of California, San Diego, CA 92093 (United States); Murray, Norman, E-mail: cmartin@physics.ucsb.edu [Canadian Institute for Theoretical Astrophysics, 60 St. George Street, University of Toronto, Toronto, ON M5S 3H8 (Canada)

    2013-06-10T23:59:59.000Z

    Mapping Mg II resonance emission scattered by galactic winds offers a means to determine the spatial extent and density of the warm outflow. Using Keck/LRIS spectroscopy, we have resolved scattered Mg II emission to the east of 32016857, a star-forming galaxy at z = 0.9392 with an outflow. The Mg II emission from this galaxy exhibits a P-Cygni profile, extends further than both the continuum and [O II] emission along the eastern side of the slit, and has a constant Doppler shift along the slit which does not follow the velocity gradient of the nebular [O II] emission. Using the Sobolev approximation, we derive the density of Mg{sup +} ions at a radius of 12-18 kpc in the outflow. We model the ionization correction and find that much of the outflowing Mg is in Mg{sup ++}. We estimate that the total mass flux could be as large as 330-500 M{sub Sun} yr{sup -1}, with the largest uncertainties coming from the depletion of Mg onto grains and the clumpiness of the warm outflow. We show that confining the warm clouds with a hot wind reduces the estimated mass flux of the warm outflow and indicates a mass-loading factor near unity in the warm phase alone. Based on the high blue luminosities that distinguish 32016857 and TKRS 4389, described by Rubin et al., from other galaxies with P-Cygni emission, we suggest that, as sensitivity to diffuse emission improves, scattering halos may prove to be a generic property of star-forming galaxies at intermediate redshifts.

  5. THE ANATOMY OF THE YOUNG PROTOSTELLAR OUTFLOW HH 211

    SciTech Connect (OSTI)

    Tappe, A.; Forbrich, J.; Lada, C. J. [Harvard-Smithsonian Center for Astrophysics, 60 Garden Street, MS-72, Cambridge, MA 02138 (United States); Martin, S. [European Southern Observatory, Alonso de Cordova 3107, Vitacura, Casilla 19001, Santiago 19 (Chile); Yuan, Y., E-mail: atappe@cfa.harvard.edu [Department of Physics and Astronomy, Johns Hopkins University, 3400 North Charles Street, Baltimore, MD 21218 (United States)

    2012-05-20T23:59:59.000Z

    We present Spitzer Space Telescope 5-36 {mu}m mapping observations toward the southeastern lobe of the young protostellar outflow HH 211. The southeastern terminal shock of the outflow shows a rich mid-infrared spectrum including molecular emission lines from OH, H{sub 2}O, HCO{sup +}, CO{sub 2}, H{sub 2}, and HD. The spectrum also shows a rising infrared continuum toward 5 {mu}m, which we interpret as unresolved emission lines from highly excited rotational levels of the CO v = 1-0 fundamental band. This interpretation is supported by a strong excess flux observed in the Spitzer/IRAC 4-5 {mu}m channel 2 image compared to the other IRAC channels. The extremely high critical densities of the CO v = 1-0 ro-vibrational lines and a comparison to H{sub 2} and CO excitation models suggest jet densities larger than 10{sup 6} cm{sup -3} in the terminal shock. We also observed the southeastern terminal outflow shock with the Submillimeter Array and detected pure rotational emission from CO 2-1, HCO{sup +} 3-2, and HCN 3-2. The rotationally excited CO traces the collimated outflow backbone as well as the terminal shock. HCN traces individual dense knots along the outflow and in the terminal shock, whereas HCO{sup +} solely appears in the terminal shock. The unique combination of our mid-infrared and submillimeter observations with previously published near-infrared observations allow us to study the interaction of one of the youngest known protostellar outflows with its surrounding molecular cloud. Our results help us to understand the nature of some of the so-called green fuzzies (Extended Green Objects), and elucidate the physical conditions that cause high OH excitation and affect the chemical OH/H{sub 2}O balance in protostellar outflows and young stellar objects. In an appendix to this paper, we summarize our Spitzer follow-up survey of protostellar outflow shocks to find further examples of highly excited OH occurring together with H{sub 2}O and H{sub 2}.

  6. Investigation of Created Fracture Geometry through Hydraulic Fracture Treatment Analysis

    E-Print Network [OSTI]

    Ahmed, Ibraheem 1987-

    2012-11-30T23:59:59.000Z

    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...

  7. Reservoir fracture characterizations from seismic scattered waves

    E-Print Network [OSTI]

    Fang, Xinding

    2012-01-01T23:59:59.000Z

    The measurements of fracture parameters, such as fracture orientation, fracture density and fracture compliance, in a reservoir is very important for field development and exploration. Traditional seismic methods for ...

  8. INTRODUCTION Permeability is a critical geologic parameter,

    E-Print Network [OSTI]

    Manning, Craig

    a fundamental role in mass and heat transfer and crustal rheology (e.g., Ingebritsen and Sanford, 1998 result. In contrast, the primary data from studies of meta- morphic systems consist of time-integrated fluid- flux (Q, or qt) estimates, which must be trans- lated to time-averaged permeabilities through (2

  9. WINTER PERFORMANCE ASSESSMENT OF PERMEABLE PAVEMENTS

    E-Print Network [OSTI]

    WINTER PERFORMANCE ASSESSMENT OF PERMEABLE PAVEMENTS A COMPARATIVE STUDY OF POROUS ASPHALT, PERVIOUS CONCRETE, AND CONVENTIONAL ASPHALT IN A NORTHERN CLIMATE BY KRISTOPHER M. HOULE BS, Worcester the University of New Hampshire, the Northern New England Concrete Promotion Association (NNECPA), the Northeast

  10. Effective Permeability Change in Wellbore Cement with Carbon Dioxide Reaction

    SciTech Connect (OSTI)

    Um, Wooyong; Jung, Hun Bok; Martin, Paul F.; McGrail, B. Peter

    2011-11-01T23:59:59.000Z

    Portland cement, a common sealing material for wellbores for geological carbon sequestration was reacted with CO{sub 2} in supercritical, gaseous, and aqueous phases at various pressure and temperature conditions to simulate cement-CO{sub 2} reaction along the wellbore from carbon injection depth to the near-surface. Hydrated Portland cement columns (14 mm diameter x 90 mm length; water-to-cement ratio = 0.33) including additives such as steel coupons and Wallula basalt fragments were reacted with CO{sub 2} in the wet supercritical (the top half) and dissolved (the bottom half) phases under carbon sequestration condition with high pressure (10 MPa) and temperature (50 C) for 5 months, while small-sized hydrated Portland cement columns (7 mm diameter x 20 mm length; water-to-cement ratio = 0.38) were reacted with CO{sub 2} in dissolved phase at high pressure (10 MPa) and temperature (50 C) for 1 month or with wet CO{sub 2} in gaseous phase at low pressure (0.2 MPa) and temperature (20 C) for 3 months. XMT images reveal that the cement reacted with CO{sub 2} saturated groundwater had degradation depth of {approx}1 mm for 1 month and {approx}3.5 mm for 5 month, whereas the degradation was minor with cement exposure to supercritical CO{sub 2}. SEM-EDS analysis showed that the carbonated cement was comprised of three distinct zones; the innermost less degraded zone with Ca atom % > C atom %, the inner degraded zone with Ca atom % {approx} C atom % due to precipitation of calcite, the outer degraded zone with C atom % > Ca atom % due to dissolution of calcite and C-S-H, as well as adsorption of carbon to cement matrix. The outer degraded zone of carbonated cement was porous and fractured because of dissolution-dominated reaction by carbonic acid exposure, which resulted in the increase in BJH pore volume and BET surface area. In contrast, cement-wet CO{sub 2}(g) reaction at low P (0.2 MPa)-T (20 C) conditions for 1 to 3 months was dominated by precipitation of micron-sized calcite on the outside surface of cement, which resulted in the decrease in BJH pore volume and BET surface area. Cement carbonation and pore structure change are significantly dependent on pressure and temperature conditions as well as the phase of CO{sub 2}, which controls the balance between precipitation and dissolution in cement matrix. Geochemical modeling result suggests that ratio of solid (cement)-to-solution (carbonated water) has a significant effect on cement carbonation, thus the cement-CO{sub 2} reaction experiment needs to be conducted under realistic conditions representing the in-situ wellbore environment of carbon sequestration field site. Total porosity and air permeability for a duplicate cement column with water-to-cement ratio of 0.38 measured after oven-drying by Core Laboratories using Boyle's Law technique and steady-state method were 31% and 0.576 mD. A novel method to measure the effective liquid permeability of a cement column using X-ray micro-tomography images after injection of pressurized KI (potassium iodide) is under development by PNNL. Preliminary results indicate the permeability of a cement column with water-to-cement ratio of 0.38 is 4-8 mD. PNNL will apply the method to understand the effective permeability change of Portland cement by CO{sub 2}(g) reaction under a variety of pressure and temperature conditions to develop a more reliable well-bore leakage risk model.

  11. ARE MOLECULAR OUTFLOWS AROUND HIGH-MASS STARS DRIVEN BY IONIZATION FEEDBACK?

    SciTech Connect (OSTI)

    Peters, Thomas; Klessen, Ralf S. [Institut fuer Theoretische Astrophysik, Universitaet Heidelberg, Zentrum fuer Astronomie, Albert-Ueberle-Str. 2, D-69120 Heidelberg (Germany); Klaassen, Pamela D. [European Southern Observatory, Karl-Schwarzschild-Strasse 2, D-85748 Garching (Germany); Mac Low, Mordecai-Mark [Department of Astrophysics, American Museum of Natural History, 79th Street at Central Park West, New York, NY 10024-5192 (United States); Banerjee, Robi, E-mail: tpeters@physik.uzh.ch [Hamburger Sternwarte, Gojenbergsweg 112, D-21029 Hamburg (Germany)

    2012-11-20T23:59:59.000Z

    The formation of massive stars exceeding 10 M {sub Sun} usually results in large-scale molecular outflows. Numerical simulations, including ionization, of the formation of such stars show evidence for ionization-driven molecular outflows. Here we examine whether the outflows seen in these models reproduce the observations. We compute synthetic ALMA and CARMA maps of CO emission lines of the outflows, and compare their signatures to existing single-dish and interferometric data. We find that the ionization-driven models can only reproduce weak outflows around high-mass star-forming regions. We argue that expanding H II regions probably do not represent the dominant mechanism for driving observed outflows. We suggest instead that observed outflows are driven by the collective action of the outflows from the many lower-mass stars that inevitably form around young massive stars in a cluster.

  12. Parameter estimation from flowing fluid temperature logging data in unsaturated fractured rock using multiphase inverse modeling

    SciTech Connect (OSTI)

    Mukhopadhyay, S.; Tsang, Y.; Finsterle, S.

    2009-01-15T23:59:59.000Z

    A simple conceptual model has been recently developed for analyzing pressure and temperature data from flowing fluid temperature logging (FFTL) in unsaturated fractured rock. Using this conceptual model, we developed an analytical solution for FFTL pressure response, and a semianalytical solution for FFTL temperature response. We also proposed a method for estimating fracture permeability from FFTL temperature data. The conceptual model was based on some simplifying assumptions, particularly that a single-phase airflow model was used. In this paper, we develop a more comprehensive numerical model of multiphase flow and heat transfer associated with FFTL. Using this numerical model, we perform a number of forward simulations to determine the parameters that have the strongest influence on the pressure and temperature response from FFTL. We then use the iTOUGH2 optimization code to estimate these most sensitive parameters through inverse modeling and to quantify the uncertainties associated with these estimated parameters. We conclude that FFTL can be utilized to determine permeability, porosity, and thermal conductivity of the fracture rock. Two other parameters, which are not properties of the fractured rock, have strong influence on FFTL response. These are pressure and temperature in the borehole that were at equilibrium with the fractured rock formation at the beginning of FFTL. We illustrate how these parameters can also be estimated from FFTL data.

  13. Integrated seismic study of naturally fractured tight gas reservoirs. Technical progress report, October 1, 1993--December 31, 1993

    SciTech Connect (OSTI)

    Mavko, G.; Nur, A.

    1994-01-29T23:59:59.000Z

    This was the ninth quarter of the contract. During this quarter we (1) continued processing the seismic data, (2) collected additional logs to aid in the interpretation, and (3)began modeling some of the P-wave amplitude anomalies that we see in the data. The study area is located at the southern end of the powder river Basin in Converse county in east-central Wyoming. It is a low permeability fractured site, with both has and oil present. Reservoirs are highly compartmentalized due tot he low permeabilities, and fractures provide the only practical drainage paths for production. The two formations of interest are: The Niobrara; a fractured shale and limey shale to chalk, which is a reservoir rock, but also its own source rock. The Frontier, a tight sandstone lying directly below the Niobrara, brought into contract with it by an unconformity.

  14. Integrated seismic study of naturally fractured tight gas reservoirs. Technical progress report, January 1, 1994--March 31, 1994

    SciTech Connect (OSTI)

    Mavko, G.; Nur, A.

    1994-04-29T23:59:59.000Z

    The study area is located at the southern end of the Powder River Basin in Converse County in east-central Wyoming. It is a low permeability fractured site, with both gas and oil present. Reservoirs are highly compartmentalized due to the low permeabilities, and fractures provide the only practical drainage paths for production. The two formations of interest are: The Niobrara, a fractured shale and limey shale to chalk, which is a reservoir rock, but also its own source rock; and the Frontier, a tight sandstone lying directly below the Niobrara, brought into contact with it by an unconformity. This was the tenth quarter of the contract. During this quarter the investigators (1) continued processing the seismic data, and (2) continued modeling some of the P-wave amplitude anomalies that we see in the data.

  15. Fracture induced anisotropy in viscoelastic media

    E-Print Network [OSTI]

    santos,,,

    ... seismology and mining. Fractures constitute the sources of earthquakes, and hydrocarbon and geothermal reservoirs are mainly composed of fractured rocks.

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

    Broader source: Energy.gov (indexed) [DOE]

    Seismic Fracture Characterization Methods for Enhanced Geothermal Systems Seismic Fracture Characterization Methods for Enhanced Geothermal Systems Project objective: Make Seismic...

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

    Broader source: Energy.gov (indexed) [DOE]

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

  18. Double torsion testing and finite element analysis for determining the electric fracture properties of piezoelectric ceramics

    SciTech Connect (OSTI)

    Shindo, Yasuhide; Narita, Fumio; Mikami, Masaru [Department of Materials Processing, Graduate School of Engineering, Tohoku University, Aoba-yama 6-6-02, Sendai 980-8579 (Japan)

    2005-06-01T23:59:59.000Z

    This paper presents the results of an experimental and numerical investigation in electric fracture behavior of composite [Pb(Zr,Ti)O{sub 3}] double torsion (DT) specimens. DT tests were conducted on a commercial piezoelectric ceramic bonded between two metals. Fracture loads under different electric fields were obtained from the experiment. Nonlinear three-dimensional finite element analysis was also employed to calculate the energy release rate for DT specimens based on the exact (permeable) and approximate (impermeable) crack models. The effects of applied electric field and domain switching on the energy release rate are discussed, and the model predictions are compared with the results of the experiments.

  19. Moisture Durability of Vapor Permeable Insulating Sheathing (Fact Sheet)

    SciTech Connect (OSTI)

    Not Available

    2013-10-01T23:59:59.000Z

    In this project, Building America team Building Science Corporation researched some of the ramifications of using exterior, vapor permeable insulation on retrofit walls with vapor permeable cavity insulation. Retrofit strategies are a key factor in reducing exterior building stock consumption.

  20. Permeability anisotropy and resistivity anisotropy of mechanically compressed mudrocks

    E-Print Network [OSTI]

    Adams, Amy Lynn

    2014-01-01T23:59:59.000Z

    Permeability anisotropy (the ratio of the horizontal to vertical permeability) is an important parameter used in sedimentary basin models and geotechnical design to model fluid flow, locate hydrocarbon reserves and estimate ...

  1. Semi-analytical estimates of permeability obtained from capillary pressure 

    E-Print Network [OSTI]

    Huet, Caroline Cecile

    2006-04-12T23:59:59.000Z

    The objective of this research is to develop and test a new concept for predicting permeability from routine rock properties. First, we develop a model predicting permeability as a function of capillary pressure. Our model, ...

  2. Modeling of multiphase flow in permeable media: (1) Mathematical model; (2) Analysis of imbibition and drying experiments

    SciTech Connect (OSTI)

    Bixler, N.E.; Eaton, R.R.

    1986-12-31T23:59:59.000Z

    Calculating multiphase flow of water through fractured porous media, such as volcanic tuff, is a numerically challenging problem because of the highly nonlinear material characteristics of permeability and saturation which describe liquid and gas transport. Typically, the permeability of the fractured host rock being investigated for an underground nuclear waste repository at Yucca Mountain, Nevada increases by 15 orders of magnitude as the rock becomes saturated. Furthermore, permeability may vary by five orders of magnitude between geologic strata. Other nonlinear mechanisms - Knudsen diffusion, binary diffusion, vapor pressure lowering, and adsorption of vapor onto pore walls - may also strongly affect liquid and gas transport. In Part I of the presentation, the mathematical model and its computer implementation are presented. The application of these equations and solution procedures to problems related to underground waste repositories are addressed in Part II. Predicted results will be compared with the results of laboratory experiments in which a core of volcanic tuff has first undergone controlled imbibition, then drying. The importance of the various transport mechanisms is demonstrated by examining the predicted results. 14 figs.

  3. Characterization and simulation of an exhumed fractured petroleum reservoir. Final report, March 18, 1996--September 30, 1998

    SciTech Connect (OSTI)

    Forster, C.B.; Nielson, D.L.; Deo, M.

    1998-12-01T23:59:59.000Z

    An exhumed fractured reservoir located near Alligator Ridge in central Nevada provides the basis for developing and testing different approaches for simulating fractured petroleum reservoirs. The fractured analog reservoir comprises a 90 m thickness of silty limestone and shaly interbeds within the Devonian Pilot Shale. A period of regional compression followed by ongoing basin and range extension has created faults and fractures that, in tern, have controlled the migration of both oil and gold ore-forming fluids. Open pit gold mines provide access for observing oil seepage, collecting the detailed fracture data needed to map variations in fracture intensity near faults, build discrete fracture network models and create equivalent permeability structures. Fault trace patterns mapped at the ground surface provide a foundation for creating synthetic fault trace maps using a stochastic procedure conditioned by the outcrop data. Conventional simulations of petroleum production from a 900 by 900 m sub-domain within the reservoir analog illustrate the possible influence of faults and fractures on production. The consequences of incorporating the impact of different stress states (e.g., extension, compression or lithostatic) are also explored. Simulating multiphase fluid flow using a discrete fracture, finite element simulator illustrates how faults acting as conduits might be poorly represented by the upscaling procedures used to assign equivalent permeability values within reservoir models. The parallelized reservoir simulators developed during this project provide a vehicle to evaluate when it might be necessary to incorporate very fine scale grid networks in conventional reservoir simulators or to use finely gridded discrete fracture reservoir simulators.

  4. Chemical Signatures of and Precursors to Fractures Using Fluid Inclusion Stratigraphy

    SciTech Connect (OSTI)

    Lorie M. Dilley

    2011-03-30T23:59:59.000Z

    Enhanced Geothermal Systems (EGS) are designed to recover heat from the subsurface by mechanically creating fractures in subsurface rocks. Open or recently closed fractures would be more susceptible to enhancing the permeability of the system. Identifying dense fracture areas as well as large open fractures from small fracture systems will assist in fracture stimulation site selection. Geothermal systems are constantly generating fractures (Moore, Morrow et al. 1987), and fluids and gases passing through rocks in these systems leave small fluid and gas samples trapped in healed microfractures. These fluid inclusions are faithful records of pore fluid chemistry. Fluid inclusions trapped in minerals as the fractures heal are characteristic of the fluids that formed them, and this signature can be seen in fluid inclusion gas analysis. This report presents the results of the project to determine fracture locations by the chemical signatures from gas analysis of fluid inclusions. With this project we hope to test our assumptions that gas chemistry can distinguish if the fractures are open and bearing production fluids or represent prior active fractures and whether there are chemical signs of open fracture systems in the wall rock above the fracture. Fluid Inclusion Stratigraphy (FIS) is a method developed for the geothermal industry which applies the mass quantification of fluid inclusion gas data from drill cuttings and applying known gas ratios and compositions to determine depth profiles of fluid barriers in a modern geothermal system (Dilley, 2009; Dilley et al., 2005; Norman et al., 2005). Identifying key gas signatures associated with fractures for isolating geothermal fluid production is the latest advancement in the application of FIS to geothermal systems (Dilley and Norman, 2005; Dilley and Norman, 2007). Our hypothesis is that peaks in FIS data are related to location of fractures. Previous work (DOE Grant DE-FG36-06GO16057) has indicated differences in the chemical signature of fluid inclusions between open and closed fractures as well as differences in the chemical signature of open fractures between geothermal systems. Our hypothesis is that open fracture systems can be identified by their FIS chemical signature; that there are differences based on the mineral assemblages and geology of the system; and that there are chemical precursors in the wall rock above open, large fractures. Specific goals for this project are: (1) To build on the preliminary results which indicate that there are differences in the FIS signatures between open and closed fractures by identifying which chemical species indicate open fractures in both active geothermal systems and in hot, dry rock; (2) To evaluate the FIS signatures based on the geology of the fields; (3) To evaluate the FIS signatures based on the mineral assemblages in the fracture; and (4) To determine if there are specific chemical signatures in the wall rock above open, large fractures. This method promises to lower the cost of geothermal energy production in several ways. Knowledge of productive fractures in the boreholes will allow engineers to optimize well production. This information can aid in well testing decisions, well completion strategies, and in resource calculations. It will assist in determining the areas for future fracture enhancement. This will develop into one of the techniques in the 'tool bag' for creating and managing Enhanced Geothermal Systems.

  5. Fracture prediction in metal sheets

    E-Print Network [OSTI]

    Lee, Young-Woong

    2005-01-01T23:59:59.000Z

    One of the most important failure modes of thin-walled structures is fracture. Fracture is predominantly tensile in nature and, in most part, is operated by the physical mechanisms of void nucleation, growth, and linkage. ...

  6. Self-potential observations during hydraulic fracturing

    E-Print Network [OSTI]

    Moore, J R; Glaser, Steven D

    2007-01-01T23:59:59.000Z

    1968), Permeability of granite under high pressure, J.permeability of Westerly granite, J. Geophys. Res. , 80(5),resistivity during creep in granite, Pure Appl. Geophys. ,

  7. PROTOSTELLAR OUTFLOW HEATING IN A GROWING MASSIVE PROTOCLUSTER

    SciTech Connect (OSTI)

    Wang Ke; Wu Yuefang; Zhang Huawei [Department of Astronomy, School of Physics, Peking University, Beijing 100871 (China); Zhang Qizhou [Harvard-Smithsonian Center for Astrophysics, 60 Garden Street, Cambridge, MA 02138 (United States); Li Huabai, E-mail: kwang@cfa.harvard.edu [Max-Planck Institute for Astronomy, Koenigstuhl 17, D-69117 Heidelberg (Germany)

    2012-02-15T23:59:59.000Z

    The dense molecular clump P1 in the infrared dark cloud complex G28.34+0.06 harbors a massive protostellar cluster at its extreme youth. Our previous Submillimeter Array observations revealed several jet-like CO outflows emanating from the protostars, indicative of intense accretion and potential interaction with ambient natal materials. Here, we present the Expanded Very Large Array spectral line observations toward P1 in the NH{sub 3} (J,K) = (1,1), (2,2), (3,3) lines, as well as H{sub 2}O and class I CH{sub 3}OH masers. Multiple NH{sub 3} transitions reveal the heated gas widely spread in the 1 pc clump. The temperature distribution is highly structured; the heated gas is offset from the protostars, and morphologically matches the outflows very well. Hot spots of spatially compact, spectrally broad NH{sub 3} (3,3) emission features are also found coincident with the outflows. A weak NH{sub 3} (3,3) maser is discovered at the interface between an outflow jet and the ambient gas. These findings suggest that protostellar heating may not be effective in suppressing fragmentation during the formation of massive cores.

  8. Nucleosynthesis in the Outflow from Gamma Ray Burst Accretion Disks

    E-Print Network [OSTI]

    R. Surman; G. C. McLaughlin; W. R. Hix

    2005-09-13T23:59:59.000Z

    We examine the nucleosynthesis products that are produced in the outflow from rapidly accreting disks. We find that the type of element synthesis varies dramatically with the degree of neutrino trapping in the disk and therefore the accretion rate of the disk. Disks with relatively high accretion rates such as 10 M_solar/s can produce very neutron rich nuclei that are found in the r process. Disks with more moderate accretion rates can produce copious amounts of Nickel as well as the light elements such as Lithium and Boron. Disks with lower accretion rates such as 0.1 M_solar/s produce large amounts of Nickel as well as some unusual nuclei such as Ti-49, Sc-45, Zn-64, and Mo-92. This wide array of potential nucleosynthesis products is due to the varying influence of electron neutrinos and antineutrinos emitted from the disk on the neutron-to-proton ratio in the outflow. We use a parameterization for the outflow and discuss our results in terms of entropy and outflow acceleration.

  9. Satellite observations of Mexico City pollution outflow from the Tropospheric Emissions Spectrometer (TES)

    E-Print Network [OSTI]

    Satellite observations of Mexico City pollution outflow from the Tropospheric Emissions 12 November 2008 Keyword: Mega-city pollution TES O3­CO correlation INTEX-B Mexico city a b s t r a c regions were used to examine Mexico City pollution outflow on a regional scale. The pollution outflow from

  10. EXPERIMENTAL DETERMINATION OF STEAM WATER RELATIVE PERMEABILITY RELATIONS

    E-Print Network [OSTI]

    Stanford University

    EXPERIMENTAL DETERMINATION OF STEAM WATER RELATIVE PERMEABILITY RELATIONS A REPORT SUBMITTED;Abstract A set of relative permeability relations for simultaneous ow of steam and water in porous media with saturation and pressure measurements. These relations show that the relative permeability for steam phase

  11. The impact of gravity segregation on multiphase non-Darcy flow in hydraulically fractured gas wells

    E-Print Network [OSTI]

    Dickins, Mark Ian

    2008-10-10T23:59:59.000Z

    Solution for Uniform Influx................................. 28 2.5 Effect of Stress on Non-Darcy Flow with Uniform Influx............................. 40 2.6 Hydraulically Fractured Reservoir with Two-Phase Flow ............................. 45 2... ............................................................................................................... 21 2.6 Gas expansion factor divided by gas viscosity Eg/µg = 1/(Bµ), which is roughly constant at or above pressures of 6,000 psi. .................................... 22 2.7 Relative permeability functions from Table 2.1 normalized...

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

    SciTech Connect (OSTI)

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

    2013-08-01T23:59:59.000Z

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

  13. PERMEABILITY TESTING OF SIMULATED SALTSTONE CORE AND VAULT 4 CELL E SALTSTONE

    SciTech Connect (OSTI)

    Nichols, R.; Dixon, K.

    2011-08-22T23:59:59.000Z

    The Engineering Process Development Group (EPD) of the Savannah River National Laboratory (SRNL) prepared simulated saltstone core samples to evaluate the effect of sample collection by coring on the permeability of saltstone. The Environmental Restoration Technology Section (ERTS) of the SRNL was given the task of measuring the permeability of cores of simulated saltstone. Saltstone samples collected from Vault 4 Cell E using both dry and wet coring methods were also submitted for permeability analysis. The cores from Vault 4 Cell E were in multiple pieces when they were recovered (Smith, 2008 Cheng et.al, 2009). Permeability testing was only performed on the portions of the core sample that were intact, had no visible fractures or cracks, and met the specifications for 'undisturbed specimens' identified in Method ASTM D5084-03 Standard Test Methods for Measurement of Hydraulic Conductivity of Saturated Porous Materials Using a Flexible Wall Permeameter that was used for the testing. Permeability values for cores of simulated saltstone compared with values from permeability tests conducted on molded saltstone samples by an independent laboratory using the same method. All hydraulic conductivity results for Vault 4 samples exceeded results for both molded and cored saltstone simulant samples. The average hydraulic conductivity result for Vault 4 Cell E samples of 3.9 x 10{sup -7} cm/sec is approximately two orders of magnitude greater than that of the simulated saltstone with an average of 4.1 x 10{sup -9} cm/sec. Numerical flow and transport simulations of moisture movement through saltstone performed for the performance assessment of the Saltstone Disposal Facility (SDF) used 2.0 x 10{sup -9} cm/sec for the hydraulic conductivity of saltstone (Flach et al, 2009). The results for simulated versus actual saltstone were further compared using non-parametric statistics. The results from non-parametric statistical analysis of results indicate that there is at least a 98% probability that the hydraulic conductivity of saltstone samples collected from Vault 4 Cell E saltstone is greater than that of the baseline simulant mix.

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

    E-Print Network [OSTI]

    Wu, Yu-Shu; Pruess, Karsten

    2004-01-01T23:59:59.000Z

    of naturally fractured reservoirs with uniform fracturefor naturally fractured reservoirs, SPE-11688, Presented atflow simulations in fractured reservoirs, Report LBL- 15227,

  15. Laboratory imaging of stimulation fluid displacement from hydraulic fractures

    SciTech Connect (OSTI)

    Tidwell, V. [Sandia National Lab., Albuquerque, NM (United States); Parker, M. [SPE, Richardson, TX (United States)

    1996-11-01T23:59:59.000Z

    Laboratory experiments were conducted to physically investigate the processes governing stimulation fluid displacement from hydraulic fractures. Experiments were performed on two scales: meter-scale in a 1500 cm{sup 2} sand pack and core-scale in a 65 cm{sup 2} API linear conductivity cell. High-resolution light transmission imaging was employed at the meter-scale to visualize and quantify processes governing fluid displacement. For comparison, complimentary tests were performed using an API conductivity cell under ambient test conditions and at elevated closure stress. In these experiments viscous fingering and gravity drainage were identified as the dominant processes governing fluid displacement. Fluid viscosity was found to dictate the relative importance of the competing displacement processes and ultimately determine the residual liquid saturation of the sand pack. The process by which fluid displacement occurs was seen to effect the shape of both the gas and liquid phase relative permeability functions. Knowledge of such viscosity/relative permeability relationships may prove useful in bounding predictions of post-stimulation recovery of gels from the fracture pack.

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

    E-Print Network [OSTI]

    Correa Castro, Juan

    2011-08-08T23:59:59.000Z

    EVALUATION AND EFFECT OF FRACTURING FLUIDS ON FRACTURE CONDUCTIVITY IN TIGHT GAS RESERVOIRS USING DYNAMIC FRACTURE CONDUCTIVITY TEST A Thesis by JUAN CARLOS CORREA CASTRO Submitted to the Office of Graduate Studies of Texas A... in Tight Gas Reservoirs Using Dynamic Fracture Conductivity Test Copyright 2011 Juan Carlos Correa Castro EVALUATION AND EFFECT OF FRACTURING FLUIDS ON FRACTURE CONDUCTIVITY IN TIGHT GAS RESERVOIRS USING DYNAMIC FRACTURE CONDUCTIVITY TEST A...

  17. Endothelial cell permeability to water and antipyrine

    SciTech Connect (OSTI)

    Garrick, R.A.

    1986-03-05T23:59:59.000Z

    The endothelium provides a structural barrier between plasma constituents and the tissues. The permeability characteristics of the the endothelial cells regulate the transcellular movement of materials across this barrier while other movement is paracellular. In this study the permeability of the endothelial cells to tritiated water (/sup 3/HHO) and /sup 14/C-labeled antipyrine (AP) was investigated. The cells were isolated non-enzymatically from calf pulmonary artery and were maintained in culture and used between the seventh and fifteenth passage. The cells were removed from the T-flasks with a rubber policeman, titurated with a 22g needle and centrifuged. The cells were mixed with an extracellular marker, drawn into polyethylene tubing and packed by centrifugation for use in the linear diffusion technique. All measurements were made at 37 C. The diffusion coefficients for /sup 3/HHO through the packed cells (D), the intracellular material (D/sub 2/), and the extracellular material (D/sub 1/) were 0.682, 0.932 and 2.45 x 10/sup -5/ cm/sup 2/ s/sup -1/ and for AP were 0.273, 0.355 and 1.13 x 10/sup -5/ cm/sup 2/ s/sup -1/ respectively. The permeability coefficient calculated by the series-parallel pathway model for /sup 3/HHO was higher than that for AP and for both /sup 3/HHO and AP were lower than those calculated for isolated lung cells and erythrocytes.

  18. Atrial natriuretic factor increases vascular permeability

    SciTech Connect (OSTI)

    Lockette, W.; Brennaman, B. (Wayne State Univ. School of Medicine, Detroit, MI (USA))

    1990-12-01T23:59:59.000Z

    An increase in central blood volume in microgravity may result in increased plasma levels of atrial natriuretic factor (ANF). Since elevations in plasma ANF are found in clinical syndromes associated with edema, and since space motion sickness induced by microgravity is associated with an increase in central blood volume and facial edema, we determined whether ANF increases capillary permeability to plasma protein. Conscious, bilaterally nephrectomized male rats were infused with either saline, ANF + saline, or hexamethonium + saline over 2 h following bolus injections of 125I-albumin and 14C-dextran of similar molecular size. Blood pressure was monitored and serial determinations of hematocrits were made. Animals infused with 1.0 micrograms.kg-1.min-1 ANF had significantly higher hematocrits than animals infused with saline vehicle. Infusion of ANF increased the extravasation of 125I-albumin, but not 14C-dextran from the intravascular compartment. ANF also induced a depressor response in rats, but the change in blood pressure did not account for changes in capillary permeability to albumin; similar depressor responses induced by hexamethonium were not accompanied by increased extravasation of albumin from the intravascular compartment. ANF may decrease plasma volume by increasing permeability to albumin, and this effect of ANF may account for some of the signs and symptoms of space motion sickness.

  19. Discovery of superthermal hydroxyl (OH) in the HH211 outflow

    E-Print Network [OSTI]

    A. Tappe; C. J. Lada; J. H. Black; A. A. Muench

    2008-05-12T23:59:59.000Z

    We present a 5-37 micron infrared spectrum obtained with the Spitzer Space Telescope toward the southeastern lobe of the young protostellar outflow HH211. The spectrum shows an extraordinary sequence of OH emission lines arising in highly excited rotational levels up to an energy E/k~28200K above the ground level. This is, to our knowledge, by far the highest rotational excitation of OH observed outside Earth. The spectrum also contains several pure rotational transitions of H2O (v=0), H2 (v=0) S(0) to S(7), HD (v=0) R(3) to R(6), and atomic fine-structure lines of [Fe II], [Si II], [Ne II], [S I], and [Cl I]. The origin of the highly excited OH emission is most likely the photodissociation of H2O by the UV radiation generated in the terminal outflow shock of HH211.

  20. Discovery of superthermal hydroxyl (OH) in the HH211 outflow

    E-Print Network [OSTI]

    Tappe, A; Black, J H; Muench, A A

    2008-01-01T23:59:59.000Z

    We present a 5-37 micron infrared spectrum obtained with the Spitzer Space Telescope toward the southeastern lobe of the young protostellar outflow HH211. The spectrum shows an extraordinary sequence of OH emission lines arising in highly excited rotational levels up to an energy E/k~28200K above the ground level. This is, to our knowledge, by far the highest rotational excitation of OH observed outside Earth. The spectrum also contains several pure rotational transitions of H2O (v=0), H2 (v=0) S(0) to S(7), HD (v=0) R(3) to R(6), and atomic fine-structure lines of [Fe II], [Si II], [Ne II], [S I], and [Cl I]. The origin of the highly excited OH emission is most likely the photodissociation of H2O by the UV radiation generated in the terminal outflow shock of HH211.

  1. A new coal-permeability model: Internal swelling stress and fracture-matrix interaction

    E-Print Network [OSTI]

    Liu, H.H.

    2010-01-01T23:59:59.000Z

    of carbon dioxide in coal with enhanced coalbed methaneL. Adsorption-induced coal swelling and stress: Implicationsand acid gas sequestration into coal seams. J Geophys Res. (

  2. Laboratory observations of permeability enhancement by fluid pressure oscillation of in situ fractured rock

    E-Print Network [OSTI]

    Elkhoury, Jean E.; Niemeijer, Andre; Brodsky, Emily E.; Marone, Chris

    2011-01-01T23:59:59.000Z

    Istituto Nazionale di Geofisica e Vulcanologia, Via di VignaNow at Istituto Nazionale di Geofisica e Vulcanologia, Rome,

  3. EFFECTS OF SAMPLE SIZE ON THE STRESS-PERMEABILITY RELATIONSHIP FOR NATURAL FRACTURES

    E-Print Network [OSTI]

    Gale, J.E.

    2013-01-01T23:59:59.000Z

    APPENDIX B: REFORMATORY GRANITE AND CORE DEFORMATION DATAProperties of in situ Jointed Granite," Int Mech. Min. Sci.Whole and Jointed Barrier Granite," Int. J. Rock Mech. Min.

  4. A new coal-permeability model: Internal swelling stress and fracture-matrix interaction

    E-Print Network [OSTI]

    Liu, H.H.

    2010-01-01T23:59:59.000Z

    gas sequestration into coal seams. J Geophys Res. (2007)Reservoir engineering in coal seams: Part 1 – the physicaland movement in coal seams. SPE Reservoir engineering.

  5. A New Coal-Permeability Model: Internal Swelling Stress and Fracture–Matrix Interaction

    E-Print Network [OSTI]

    Liu, Hui-Hai; Rutqvist, Jonny

    2010-01-01T23:59:59.000Z

    gas sequestration into coal seams. J Geophys. Res. (2007).Reservoir engineering in coal seams: part 1—the physicalstorage and movement in coal seams. SPE Reserv. Eng. , 2(1),

  6. EFFECTS OF SAMPLE SIZE ON THE STRESS-PERMEABILITY RELATIONSHIP FOR NATURAL FRACTURES

    E-Print Network [OSTI]

    Gale, J.E.

    2013-01-01T23:59:59.000Z

    geology problems. Rock slope design, mine drainage, and the effective exploration and development of oil,

  7. In-situ remediation of naturally occurring radioactive materials with high-permeability hydraulic fracturing

    E-Print Network [OSTI]

    Demarchos, Andronikos Stavros

    1998-01-01T23:59:59.000Z

    in the petroleum industry, is the recommended technique. NORM are found throughout subterranean formations. Whenever fluids from petroleum or water reservoirs are produced NORM are present in varying quantities. NORM can only be sensed with radiation detectors...

  8. Numerical modeling of hydraulic fracture problem in permeable medium using cohesive zone model

    E-Print Network [OSTI]

    Paris-Sud XI, Université de

    or radioactive waste [30], geothermal Corresponding author Email address: benoit.carrier@enpc.fr (Benoit Carrier processes. During the last sixty years, numerous papers [3, 7, 14, 21, 35, 34, 41, 25, 27, 22, 38, 36, 1. In the recent years, a scaling and asymptotic framework was built to determine the influence of the physical

  9. Final Report Multiazimuth Seismic Diffraction Imaging for Fracture Characterization in Low-Permeability

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

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative1 First Use of Energy for All Purposes (Fuel and Nonfuel), 2002; Level: National5Sales for4,645U.S. DOEThe Bonneville Power AdministrationField8,Dist.New Mexico Feb.Information 91, 20159,Final Reminder:Final

  10. Stresses and fractures in the Frontier Formation, Green River Basin, predicted from basin-margin tectonic element interactions

    SciTech Connect (OSTI)

    Lorenz, J.C.

    1996-01-01T23:59:59.000Z

    Natural fractures and in situ stresses commonly dictate subsurface reservoir permeability and permeability anisotropy, as well as the effectiveness of stimulation techniques in low-permeability, natural gas reservoirs. This paper offers an initial prediction for the orientations of the fracture and stress systems in the tight gas reservoirs of the Frontier Formation, in the Green River basin of southwestern Wyoming. It builds on a previous report that addressed fractures and stresses in the western part of the basin and on ideas developed for the rest of the basin, using the principle that thrust faults are capable of affecting the stress magnitudes and orientations in little-deformed strata several hundreds of kilometers in front of a thrust. The prediction of subsurface stresses and natural fracture orientations is an undertaking that requires the willingness to revise models as definitive data are acquired during drilling. The predictions made in this paper are offered with the caveat that geology in the subsurface is always full of surprises.

  11. Method for fracturing silicon-carbide coatings on nuclear-fuel particles

    DOE Patents [OSTI]

    Turner, Lloyd J. (Oak Ridge, TN); Willey, Melvin G. (Knoxville, TN); Tiegs, Sue M. (Lenoir City, TN); Van Cleve, Jr., John E. (Kingston, TN)

    1982-01-01T23:59:59.000Z

    This invention is a device for fracturing particles. It is designed especially for use in "hot cells" designed for the handling of radioactive materials. In a typical application, the device is used to fracture a hard silicon-carbide coating present on carbon-matrix microspheres containing nuclear-fuel material, such as uranium or thorium compounds. To promote remote control and facilitate maintenance, the particle breaker is pneumatically operated and contains no moving parts. It includes means for serially entraining the entrained particles on an anvil housed in a leak-tight chamber. The flow rate of the gas is at a value effecting fracture of the particles; preferably, it is at a value fracturing them into product particulates of fluidizable size. The chamber is provided with an outlet passage whose cross-sectional area decreases in the direction away from the chamber. The outlet is connected tangentially to a vertically oriented vortex-flow separator for recovering the product particulates entrained in the gas outflow from the chamber. The invention can be used on a batch or continuous basis to fracture the silicon-carbide coatings on virtually all of the particles fed thereto.

  12. Fracture Modeling and Flow Behavior in Shale Gas Reservoirs Using Discrete Fracture Networks

    E-Print Network [OSTI]

    Ogbechie, Joachim Nwabunwanne

    2012-02-14T23:59:59.000Z

    Gen and NFflow) for fracture modeling of a shale gas reservoir and also studies the interaction of the different fracture properties on reservoir response. The most important results of the study are that a uniform fracture network distribution and fracture...

  13. Procedure for estimating fracture energy from fracture surface roughness

    DOE Patents [OSTI]

    Williford, Ralph E. (Kennewick, WA)

    1989-01-01T23:59:59.000Z

    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.

  14. Diagnostics of a Subsurface Radial Outflow From a Sunspot

    E-Print Network [OSTI]

    D. C. Braun; Y. Fan; C. Lindsey; S. M. Jefferies

    1996-03-15T23:59:59.000Z

    We measure the mean frequencies of acoustic waves propagating toward and away from a sunspot employing a spot-centered Fourier-Hankel decomposition of p-mode amplitudes as measured from a set of observations made at the South Pole in 1991. We demonstrate that there is a significant frequency shift between the inward and outward traveling waves which is consistent with the Doppler effect of a radial outflow from the sunspot. For p-modes of temporal frequencies of 3 mHz it is observed that the frequency shift decreases slightly with spatial frequency, for modes with degree l between 160 to 600. From the l dependence of the frequency shift, we infer that the mean radial outflow within the observed annular region (which extends between 30 and 137 Mm from the spot) increases nearly linearly with depth, reaching a magnitude of about 200 m/s at a depth of 20 Mm. This outflow exhibits properties similar to flows recently reported by Lindsey, et al. (1996) using spatially sensitive local helioseismic techniques.

  15. A RECONNECTION-DRIVEN RAREFACTION WAVE MODEL FOR CORONAL OUTFLOWS

    SciTech Connect (OSTI)

    Bradshaw, S. J. [Department of Physics and Astronomy, Rice University, Houston, TX 77005 (United States); Aulanier, G. [LESIA, Observatoire de Paris, CNRS, UPMC, Universite Paris Diderot, 5 place Jules Janssen, 92190 Meudon (France); Del Zanna, G., E-mail: stephen.bradshaw@rice.edu [DAMTP, Centre for Mathematical Sciences, Wilberforce Road, Cambridge, CB3 0WA (United Kingdom)

    2011-12-10T23:59:59.000Z

    We conduct numerical experiments to determine whether interchange reconnection at high altitude coronal null points can explain the outflows observed as blueshifts in coronal emission lines at the boundaries between open and closed magnetic field regions. In this scenario, a strong, post-reconnection pressure gradient forms in the field-aligned direction when dense and hot, active region core loops reconnect with neighboring tenuous and cool, open field lines. We find that the pressure gradient drives a supersonic outflow and a rarefaction wave develops in both the open and closed post-reconnection magnetic field regions. We forward-model the spectral line profiles for a selection of coronal emission lines to predict the spectral signatures of the rarefaction wave. We find that the properties of the rarefaction wave are consistent with the observed velocity versus temperature structure of the corona in the outflow regions, where the velocity increases with the formation temperature of the emission lines. In particular, we find excellent agreement between the predicted and observed Fe XII 195.119 A spectral line profiles in terms of the blueshift (10 km s{sup -1}), full width at half-maximum (83 mA) and symmetry. Finally, we find that T{sub i} < T{sub e} in the open field region, which indicates that the interchange reconnection scenario may provide a viable mechanism and source region for the slow solar wind.

  16. EPA/ITRC-RTDF permeable reactive barrier short course. Permeable reactive barriers: Application and deployment

    SciTech Connect (OSTI)

    Not Available

    1999-01-01T23:59:59.000Z

    This report focuses on the following: Permeable Reactive Barriers: Application and Deployment; Introduction to Permeable Reactive Barriers (PRBs) for Remediating and Managing Contaminated Groundwater in Situ; Collection and Interpretation of Design Data 1: Site Characterization for PRBs; Reactive Materials: Zero-Valent Iron; Collection and Interpretation of Design Data 2: Laboratory and Pilot Scale Tests; Design Calculations; Compliance Monitoring, Performance Monitoring and Long-Term Maintenance for PRBs; PRB Emplacement Techniques; PRB Permitting and Implementation; Treatment of Metals; Non-Metallic Reactive Materials; Economic Considerations for PRB Deployment; and Bibliography.

  17. EPA/ITRC-RTDF permeable reactive barrier short course. Permeable reactive barriers: Application and deployment

    SciTech Connect (OSTI)

    NONE

    1999-11-01T23:59:59.000Z

    This report focuses on the following: Permeable Reactive Barriers: Application and Deployment; Introduction to Permeable Reactive Barriers (PRBs) for Remediating and Managing Contaminated Groundwater in Situ; Collection and Interpretation of Design Data 1: Site Characterization for PRBs; Reactive Materials: Zero-Valent Iron; Collection and Interpretation of Design Data 2: Laboratory and Pilot Scale Tests; Design Calculations; Compliance Monitoring, Performance Monitoring and Long-Term Maintenance for PRBs; PRB Emplacement Techniques; PRB Permitting and Implementation; Treatment of Metals; Non-Metallic Reactive Materials; Economic Considerations for PRB Deployment; and Bibliography.

  18. Hydraulic interactions between fractures and bedding planes in a carbonate aquifer studied by means of experimentally induced water-table fluctuations (Coaraze

    E-Print Network [OSTI]

    Boyer, Edmond

    1 Hydraulic interactions between fractures and bedding planes in a carbonate aquifer studied high and low permeability regions are controlled by the hydraulic head gradient. Past studies have addressed this problem mainly considering steady- state hydraulic conditions. To study such exchanges during

  19. Coordinated studies in support of hydraulic fracturing of coalbed methane. Annual report, January 1993-April 1994

    SciTech Connect (OSTI)

    Penny, G.S.; Conway, M.W.

    1994-08-01T23:59:59.000Z

    The production of natural gas from coal typically requires stimulation in the form of hydraulic fracturing and, more recently, cavity completions. The results of hydraulic fracturing treatments have ranged from extremely successful to less than satisfactory. The purpose of this work is to characterize common and potential fracturing fluids in terms of coal-fluid interactions to identify reasons for less than satisfactory performance and to ultimately devise alternative fluids and treatment procedures to optimize production following hydraulic fracturing. The laboratory data reported herein has proven helpful in designing improved hydraulic fracturing treatments and remedial treatments in the Black Warrior Basin. Acid inhibitors, scale inhibitors, additives to improve coal relative permeability to gas, and non-damaging polymer systems for hydraulic fracturing have been screened in coal damage tests. The optimum conditions for creating field-like foams in the laboratory have been explored. Tests have been run to identify minimum polymer and surfactant concentrations for applications of foam in coal. The roll of 100 mesh sand in controlling leakoff and impairing conductivity in coal has been investigated. The leakoff and proppant transport of fluids with breaker has been investigated and recommendations have been made for breaker application to minimize damage potential in coal. A data base called COAL`S has been created in Paradox (trademark) for Windows to catalogue coalbed methane activities in the Black Warrior and San Juan Basins.

  20. Numerical simulation of hydraulic fracturing

    E-Print Network [OSTI]

    Warner, Joseph Barnes

    1987-01-01T23:59:59.000Z

    ~ared that the results of such treatments were not always adequately described by the two-dimensional models. With recent advances in hydraulic fracturing and computing technology, attempts have been made to formulate more realistic fracture models. These three...NUMERICAL SIMULATION OF HYDRAULIC FRACTURING A Thesis by JOSEPH BARNES WARNER Submitted to the Graduate College of Texas A&M University in partial fulfillment of the requirements for the degree of MASTER OF SCIENCE May 1987 Maj or Subj ect...

  1. Towards a characteristic equation for permeability

    E-Print Network [OSTI]

    Siddiqui, Adil Ahmed

    2008-10-10T23:59:59.000Z

    on a fractal-based derivation of permeability from porosity. The Pape et al. result is presented as an additive power law relation, typically of the form: k = a? + b? 2 + c? 10 . We do not believe that the Pape et al. model will find significant... utility in the petroleum industry, apart from unconsolidated materials and rocks of very uniform grain sizes. We do not wish to diminish the work of Pape et al. rather we just do not see the same behavior in our rock sample data (i.e., extremely well...

  2. Gas permeable electrode for electrochemical system

    DOE Patents [OSTI]

    Ludwig, Frank A. (Rancho Palos Verdes, CA); Townsend, Carl W. (Los Angeles, CA)

    1989-01-01T23:59:59.000Z

    An electrode apparatus adapted for use in electrochemical systems having an anode compartment and a cathode compartment in which gas and ions are produced and consumed in the compartments during generation of electrical current. The electrode apparatus includes a membrane for separating the anode compartment from the cathode compartment wherein the membrane is permeable to both ions and gas. The cathode and anode for the assembly are provided on opposite sides of the membrane. During use of the membrane-electrode apparatus in electrochemical cells, the gas and ions generated at the cathode or anode migrate through the membrane to provide efficient transfer of gas and ions between the anode and cathode compartments.

  3. Gas permeability measurements for film envelope materials

    DOE Patents [OSTI]

    Ludtka, G.M.; Kollie, T.G.; Watkin, D.C.; Walton, D.G.

    1998-05-12T23:59:59.000Z

    Method and apparatus for measuring the permeability of polymer film materials such as used in super-insulation powder-filled evacuated panels (PEPs) reduce the time required for testing from several years to weeks or months. The method involves substitution of a solid non-outgassing body having a free volume of between 0% and 25% of its total volume for the usual powder in the PEP to control the free volume of the ``body-filled panel.`` Pressure versus time data for the test piece permit extrapolation to obtain long term performance of the candidate materials. 4 figs.

  4. Gas permeability measurements for film envelope materials

    DOE Patents [OSTI]

    Ludtka, Gerard M. (Oak Ridge, TN); Kollie, Thomas G. (Oak Ridge, TN); Watkin, David C. (Clinton, TN); Walton, David G. (Knoxville, TN)

    1998-01-01T23:59:59.000Z

    Method and apparatus for measuring the permeability of polymer film materials such as used in super-insulation powder-filled evacuated panels (PEPs) reduce the time required for testing from several years to weeks or months. The method involves substitution of a solid non-outgassing body having a free volume of between 0% and 25% of its total volume for the usual powder in the PEP to control the free volume of the "body-filled panel". Pressure versus time data for the test piece permit extrapolation to obtain long term performance of the candidate materials.

  5. Osmotic water permeability of human red cells

    SciTech Connect (OSTI)

    Terwilliger, T.C.; Solomon, A.K.

    1981-05-01T23:59:59.000Z

    The osmotic water permeability of human red cells has been reexamined with a stopped-flow device and a new perturbation technique. Small osmotic gradients are used to minimize the systematic error caused by nonlinearities in the relationship between cell volume and light scattering. Corrections are then made for residual systematic error. Our results show that the hydraulic conductivity, Lp, is essentially independent of the direction of water flow and of osmolality in the range 184-365 mosM. the mean value of Lp obtained obtained was 1.8 +/- 0.1 (SEM) X 10-11 cm3 dyne -1 s-1.

  6. BTEX biodegradation in fractured shale

    SciTech Connect (OSTI)

    O`Cleirigh, D.; Coryea, H. [Roy F. Weston, Inc., Austin, TX (United States); Christopher, M.; Vaughn, C. [Roy F. Weston, Inc., Houston, TX (United States)

    1997-12-31T23:59:59.000Z

    A petroleum hydrocarbon groundwater plume was identified at a Federal Aviation Administration (FAA) facility in Oklahoma. The affected area had an average BTEX concentration of 3.8 mg/L. Previous aquifer tests indicated preferential groundwater flow paths resulting from natural fractures present in the aquifer formation (primarily shale). A pneumatic fracturing pilot study was performed to evaluate the technology`s effectiveness in creating a more isotropic aquifer. As part of the study, pre-fracture/post-fracture pump tests were performed. Pre-fracture and post-fracture graphs confirmed the study`s hypothesis that pneumatic fracturing would eliminate preferential flow paths and increase groundwater yield. Based on the successful pneumatic fracturing test, an area within the petroleum hydrocarbon plume was fractured and a pilot-scale biodegradation system was operated for four months. The remediation system provided groundwater circulation amended with nutrients and oxygen. Results of the study indicated a significant decrease in BTEX concentrations between the injection well and the observation wells. By Day 113, the benzene concentration (0.044 mg/L) at one of the observation wells was less than the desired state cleanup goal of 0.05 mg/L.

  7. Fracture model for cemented aggregates

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

    Zubelewicz, Aleksander; Thompson, Darla G.; Ostoja-Starzewski, Martin; Ionita, Axinte; Shunk, Devin; Lewis, Matthew W.; Lawson, Joe C.; Kale, Sohan; Koric, Seid

    2013-01-01T23:59:59.000Z

    A mechanisms-based fracture model applicable to a broad class of cemented aggregates and, among them, plastic-bonded explosive (PBX) composites, is presented. The model is calibrated for PBX 9502 using the available experimental data under uniaxial compression and tension gathered at various strain rates and temperatures. We show that the model correctly captures inelastic stress-strain responses prior to the load peak and it predicts the post-critical macro-fracture processes, which result from the growth and coalescence of micro-cracks. In our approach, the fracture zone is embedded into elastic matrix and effectively weakens the material's strength along the plane of the dominant fracture.

  8. Interferometric hydrofracture microseism localization using neighboring fracture

    E-Print Network [OSTI]

    Poliannikov, Oleg V.

    2011-05-19T23:59:59.000Z

    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. ...

  9. Interferometric hydrofracture microseism localization using neighboring fracture

    E-Print Network [OSTI]

    Poliannikov, Oleg V.

    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. ...

  10. Fracture compliance estimation using borehole tube waves

    E-Print Network [OSTI]

    Bakku, Sudhish Kumar

    We tested two models, one for tube-wave generation and the other for tube-wave attenuation at a fracture intersecting a borehole that can be used to estimate fracture compliance, fracture aperture, and lateral extent. In ...

  11. astrocyte water permeability: Topics by E-print Network

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

    19 Predicting relative permeability from water retention: A direct approach based on fractal geometry Environmental Management and Restoration Websites Summary: curves (e.g.,...

  12. arterioso permeable por: Topics by E-print Network

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

    mol% yttria-stabilized (more) Sweeney, Sean 2005-01-01 13 Permeability prediction from well log data using multiple regression analysis. Open Access Theses and Dissertations...

  13. "EFICIENCIA DE FUNCIONAMIENTO DE LA PRB (Barrera Permeable Reactiva)

    E-Print Network [OSTI]

    Politècnica de Catalunya, Universitat

    "EFICIENCIA DE FUNCIONAMIENTO DE LA PRB (Barrera Permeable Reactiva) EN AZNALCOLLAR (ESPAÑA)" Autor Barrera Geoquímica Experimental (PRB)? ·Un emplazamiento subsuperficial de materiales reactivos ·Diseñado

  14. Mineral Precipitation Upgradient from a Zero-Valent Iron Permeable...

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

    Abstract: Core samples taken from a zero-valent iron permeable reactive barrier (ZVI PRB) at Cornhusker Army Ammunition Plant, Nebraska, were analyzed for physical and chemical...

  15. IMPROVED METHODS FOR MAPPING PERMEABILITY AND HEAT SOURCES IN...

    Open Energy Info (EERE)

    USING MICROEARTHQUAKE DATA Jump to: navigation, search OpenEI Reference LibraryAdd to library Conference Proceedings: IMPROVED METHODS FOR MAPPING PERMEABILITY AND HEAT SOURCES...

  16. A Film Depositional Model of Permeability for Mineral Reactions...

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

    to solid-aqueous phase reactions. Citation: Freedman VL, P Saripalli, DH Bacon, and PD Meyer.2004."A Film Depositional Model of Permeability for Mineral Reactions in Unsaturated...

  17. New additives for minimizing cement body permeability

    SciTech Connect (OSTI)

    Talabani, S. [Western Atlas International, Abu Dhabi (United Arab Emirates); Hareland, G. [New Mexico Inst. of Mining and Technology, Socorro, NM (United States). Dept. of Petroleum Engineering; Islam, M.R. [Univ. of Regina, Saskatchewan (Canada). Faculty of Engineering

    1999-01-01T23:59:59.000Z

    An experimental investigation was carried out with a new array of cement additives, replacing some of the currently used ones. In this study, the cement slurry pressure was monitored during the setting of the element. To obtain the optimum tightness of the cement, final contraction in the cycle is crucial for blockage of gas migration. Concentrations of the additives were obtained experimentally in this study for which the cyclic pressure behavior of the cement was optimized and the permeability reduced for the best final cement results. The parameters investigated in this study were as follows: pressure applied on the slurry with time, compressive strength, and permeability of the set cement. The major causes of the early microfractures are the incomplete cement-water reaction, low compressive strength of the set cement, and the sudden change in the hydrostatic pressure as the cement changes its phase from a liquid to a solid state. This paper reports the appropriate amounts of X-C polymer, Anchorage clay, Ironite Sponge, and synthetic rubber needed to optimize the compressive strength and eliminate both microfracture and microannulus. There are certain limits to the amount and type of synthetic rubber powder for which microfractures are eliminated. The article reports an experimental approach that can be used to eliminate gas migration through a cement design that is environmentally safe and inexpensive, using recyclable materials.

  18. Highly porous aerogels of very low permeability *

    E-Print Network [OSTI]

    J. Phalippou; T. Woignier; R. Sempéré; P. Dieudonné

    In this paper, we firstly investigate the way the pores are created in silica gel during gelation. Then we show that the solid particle arrangement acts on the geometrical pore characteristics (pore volume and pore size distribution). According to the pore size value, the permeability of gels is quite low even if the value of the gel porosity exceeds 95%. Analogous properties can be extended to silica aerogels for which now the solvent is replaced by air. Consequently, and according to their low permeability, light weight aerogels exhibit very striking response to mechanical stresses. Here we report unusual experiments allowing us to estimate the mechanical properties of aerogels thanks to their low value of the average pore size. Moreover, one demonstrates that aerogels may be densified at room temperature using an external isostatic pressure. In that case, the pore size may be tailored with respect to the nature and the characteristics of the starting aerogel. The evolution of the textural properties such as the mean pore size and the specific surface area of these tailored aerogels is investigated as a function of isostatic pressure. 1.

  19. Calculation of large scale relative permeabilities from stochastic properties of the permeability field and fluid properties

    SciTech Connect (OSTI)

    Lenormand, R.; Thiele, M.R. [Institut Francais du Petrole, Rueil Malmaison (France)

    1997-08-01T23:59:59.000Z

    The paper describes the method and presents preliminary results for the calculation of homogenized relative permeabilities using stochastic properties of the permeability field. In heterogeneous media, the spreading of an injected fluid is mainly sue to the permeability heterogeneity and viscosity fingering. At large scale, when the heterogeneous medium is replaced by a homogeneous one, we need to introduce a homogenized (or pseudo) relative permeability to obtain the same spreading. Generally, is derived by using fine-grid numerical simulations (Kyte and Berry). However, this operation is time consuming and cannot be performed for all the meshes of the reservoir. We propose an alternate method which uses the information given by the stochastic properties of the field without any numerical simulation. The method is based on recent developments on homogenized transport equations (the {open_quotes}MHD{close_quotes} equation, Lenormand SPE 30797). The MHD equation accounts for the three basic mechanisms of spreading of the injected fluid: (1) Dispersive spreading due to small scale randomness, characterized by a macrodispersion coefficient D. (2) Convective spreading due to large scale heterogeneities (layers) characterized by a heterogeneity factor H. (3) Viscous fingering characterized by an apparent viscosity ration M. In the paper, we first derive the parameters D and H as functions of variance and correlation length of the permeability field. The results are shown to be in good agreement with fine-grid simulations. The are then derived a function of D, H and M. The main result is that this approach lead to a time dependent . Finally, the calculated are compared to the values derived by history matching using fine-grid numerical simulations.

  20. YSO Jets and Molecular Outflows: Tracing the History of Star Formation

    E-Print Network [OSTI]

    Adam Frank

    1998-04-29T23:59:59.000Z

    Collimated outflows from Young Stellar Objects (YSOs) can be seen as tracers of the accretion powered systems which drive them. In this paper I review some theoretical and observational aspects of YSO outflows through the prism of questions relating to the protostellar source. The issue I address is: can collimated outflows be used as ``fossils'' allowing the history of protostellar evolution to be recovered? Answering this question relies on accurately identifying where theoretical tools and observational diagnostics converge to provide unique solutions of the protostellar physics. I discuss potential links between outflow and source including the time and direction variability of jets, the jet/molecular outflow connection, and the the effect of magnetic fields. I also discuss models of the jet/outflow collimation mechanism.

  1. Integrated seismic study of naturally fractured tight gas reservoirs. Technical progress report, April 1, 1993--June 31, 1993

    SciTech Connect (OSTI)

    Mavko, G.; Nur, A.

    1993-07-26T23:59:59.000Z

    This was the seventh quarter of the contract. During this quarter we (1) continued the large task of processing the seismic data, (2) collected additional geological information to aid in the interpretation, (3) tied the well log data to the seismic via generation of synthetic seismograms, (4) began integrating regional structural information and fracture trends with our observations of structure in the study area, (5) began constructing a velocity model for time-to-depth conversion and subsequent AVO and raytrace modeling experiments, and (6) completed formulation of some theoretical tools for relating fracture density to observed elastic anisotropy. The study area is located at the southern end of the Powder River Basin in Converse County in east-central Wyoming. It is a low permeability fractured site, with both gas and oil present. Reservoirs are highly compartmentalized due to the low permeabilities, and fractures provide the only practical drainage paths for production. The two formations of interest are: The Niobrara: a fractured shale and limey shale to chalk, which is a reservoir rock, but also its own source rock. The Frontier: a tight sandstone lying directly below the Niobrara, brought into contact with it by an unconformity. A basemap is presented with the seismic lines being analyzed for this project plus locations of 13 wells that we are using to supplement the analysis. The arrows point to two wells for which we have constructed synthetic seismograms.

  2. Mechanics of layered anisotropic poroelastic media with applications to effective stress for fluid permeability

    SciTech Connect (OSTI)

    Berryman, J.G.

    2010-06-01T23:59:59.000Z

    The mechanics of vertically layered porous media has some similarities to and some differences from the more typical layered analysis for purely elastic media. Assuming welded solid contact at the solid-solid interfaces implies the usual continuity conditions, which are continuity of the vertical (layering direction) stress components and the horizontal strain components. These conditions are valid for both elastic and poroelastic media. Differences arise through the conditions for the pore pressure and the increment of fluid content in the context of fluid-saturated porous media. The two distinct conditions most often considered between any pair of contiguous layers are: (1) an undrained fluid condition at the interface, meaning that the increment of fluid content is zero (i.e., {delta}{zeta} = 0), or (2) fluid pressure continuity at the interface, implying that the change in fluid pressure is zero across the interface (i.e., {delta}p{sub f} = 0). Depending on the types of measurements being made on the system and the pertinent boundary conditions for these measurements, either (or neither) of these two conditions might be directly pertinent. But these conditions are sufficient nevertheless to be used as thought experiments to determine the expected values of all the poroelastic coefficients. For quasi-static mechanical changes over long time periods, we expect drained conditions to hold, so the pressure must then be continuous. For high frequency wave propagation, the pore-fluid typically acts as if it were undrained (or very nearly so), with vanishing of the fluid increment at the boundaries being appropriate. Poroelastic analysis of both these end-member cases is discussed, and the general equations for a variety of applications to heterogeneous porous media are developed. In particular, effective stress for the fluid permeability of such poroelastic systems is considered; fluid permeabilities characteristic of granular media or tubular pore shapes are treated in some detail, as are permeabilities of some of the simpler types of fractured materials.

  3. Exploring the physicochemical processes that govern hydraulic fracture through laboratory

    E-Print Network [OSTI]

    Belmonte A; Connelly P

    ) containing model boreholes as an analog to hydraulic fracturing with various fracture-driving fluids. The

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

    Broader source: Energy.gov (indexed) [DOE]

    Seismic Fracture Characterization Methods for Enhanced Geothermal Systems Principal Investigator: John H. Queen Hi-Q Geophysical Inc. Track Name: Seismicity and Reservoir Fracture...

  5. Estimation of fracture flow parameters through numerical analysis of hydromechanical pressure pulses

    E-Print Network [OSTI]

    Cappa, F.

    2009-01-01T23:59:59.000Z

    an Engineered Fractured Geothermal Reservoir. Example of theinteractions in a fractured carbonate reservoir inferredwithin a shallow fractured carbonate reservoir. Fracture

  6. Spectral Evidence for Widespread Galaxy Outflows at z>4

    E-Print Network [OSTI]

    Brenda Frye; Tom Broadhurst; Narciso Benitez

    2001-12-04T23:59:59.000Z

    We present discovery spectra of a sample of eight lensed galaxies at high redshift, 3.7outflow velocity of interstellar gas. Local starburst galaxies show similar behavior, associated with obvious gas outflows. We also find a trend of increasing equivalent width of Ly-alpha emission with redshift, which may be a genuine evolutionary effect towards younger stellar populations at high redshift with less developed stellar continua. No obvious emission is detected below the Lyman limit in any of our spectra, nor in deep U or B-band images. The UV continua are reproduced well by early B-stars, although some dust absorption would allow a fit to hotter stars. After correcting for the lensing, we derive small physical sizes for our objects, ~0.5-5 kpc/h for a flat cosmology with Omega_m=0.3, Omega_Lambda=0.7. The lensed images are only marginally resolved in good seeing despite their close proximity to the critical curve, where large arcs are visible and hence high magnifications of up to ~20x are inferred. Two objects show a clear spatial extension of the Ly-alpha emission relative to the continuum starlight, indicating a ``breakout'' of the gas. The sizes of our galaxies together with their large gas motion suggests that outflows of gas are common at high redshift and associated with galaxy formation.

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

    SciTech Connect (OSTI)

    Fred Sabins

    2005-03-31T23:59:59.000Z

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

  8. Fluid permeability measurement system and method

    DOE Patents [OSTI]

    Hallman, Jr., Russell Louis (Knoxville, TN); Renner, Michael John (Oak Ridge, TN)

    2008-02-05T23:59:59.000Z

    A system for measuring the permeance of a material. The permeability of the material may also be derived. The system provides a liquid or high concentration fluid bath on one side of a material test sample, and a gas flow across the opposing side of the material test sample. The mass flow rate of permeated fluid as a fraction of the combined mass flow rate of gas and permeated fluid is used to calculate the permeance of the material. The material test sample may be a sheet, a tube, or a solid shape. Operational test conditions may be varied, including concentration of the fluid, temperature of the fluid, strain profile of the material test sample, and differential pressure across the material test sample.

  9. Ground rubber: Reactive permeable barrier sorption media

    SciTech Connect (OSTI)

    Kershaw, D.S.; Pamukcu, S. [Lehigh Univ., Bethlehem, PA (United States)

    1997-12-31T23:59:59.000Z

    The objective of this research was to examine the feasibility of using ground tire rubber as a sorbent media in reactive permeable barrier systems. Previous research by the current authors has demonstrated that tire rubber can sorb significant quantities of benzene, toluene, ethylbenzene and O-xylene from aqueous solutions. The current research was run to examine the usage rate of ground rubber in a packed bed reactor under specific contact times. In addition, desorption and repetitive sorption tests were run to determine the reversibility of the sorption process for ground tire rubber. These tests were run to determine the regeneration capacity of ground tire rubber. Results of the study show that the usage rates are greater than 50% with an empty bed contact times of 37 minutes, and minimal amounts of energy are needed to regenerate the tire rubber after use.

  10. Gas permeable electrode for electrochemical system

    DOE Patents [OSTI]

    Ludwig, F.A.; Townsend, C.W.

    1989-09-12T23:59:59.000Z

    An electrode apparatus is described which is adapted for use in electrochemical systems having an anode compartment and a cathode compartment in which gas and ions are produced and consumed in the compartments during generation of electrical current. The electrode apparatus includes a membrane for separating the anode compartment from the cathode compartment wherein the membrane is permeable to both ions and gas. The cathode and anode for the assembly are provided on opposite sides of the membrane. During use of the membrane-electrode apparatus in electrochemical cells, the gas and ions generated at the cathode or anode migrate through the membrane to provide efficient transfer of gas and ions between the anode and cathode compartments. 3 figs.

  11. Hydrogen-permeable composite metal membrane and uses thereof

    DOE Patents [OSTI]

    Edlund, David J. (Bend, OR); Friesen, Dwayne T. (Bend, OR)

    1993-06-08T23:59:59.000Z

    Various hydrogen production and hydrogen sulfide decomposition processes are disclosed that utilize composite metal membranes that contain an intermetallic diffusion barrier separating a hydrogen-permeable base metal and a hydrogen-permeable coating metal. The barrier is a thermally stable inorganic proton conductor.

  12. EXPERIMENTAL MEASUREMENT OF STEAM-WATER RELATIVE PERMEABILITY

    E-Print Network [OSTI]

    Stanford University

    EXPERIMENTAL MEASUREMENT OF STEAM-WATER RELATIVE PERMEABILITY A REPORT SUBMITTED TO THE DEPARTMENT calculations. X-ray computer tomography (CT) aided by measuring in-situ steam saturation more directly. The measured steam-water relative permeability curves assume a shape similar to those obtained by Corey (1954

  13. Modeling of Damage, Permeability Changes and Pressure Responses during Excavation of the TSX Tunnel in Granitic Rock at URL, Canada

    E-Print Network [OSTI]

    Rutqvist, Jonny

    2009-01-01T23:59:59.000Z

    Modeling of Damage, Permeability Changes and Pressureof excavation-induced damage, permeability changes, andrange of approaches to model damage and permeability changes

  14. Variability of the NGC 1333 IRAS 4A Outflow: Molecular Hydrogen and Silicon Monoxide Images

    E-Print Network [OSTI]

    Minho Choi; Klaus W. Hodapp; Masahiko Hayashi; Kentaro Motohara; Soojong Pak; Tae-Soo Pyo

    2006-04-19T23:59:59.000Z

    The NGC 1333 region was observed in the H2 1-0 S(1) line. The H2 images cover a 5' x 7' region around IRAS 4. Numerous H2 emission features were detected. The northeast-southwest bipolar outflow driven by IRAS 4A was studied by combining the H2 images with SiO maps published previously. The SiO-H2 outflows are continuous on the southwestern side but show a gap on the northeastern side. The southwestern outflow lobe curves smoothly, and the position angle increases with the distance from the driving source. The base and the outer tip of the northeastern outflow lobe are located at positions opposite to the corresponding parts of the southwestern lobe. This point-symmetry suggests that the outflow axis may be drifting or precessing clockwise in the plane of the sky and that the cause of the axis drift may be intrinsic to the outflow engine. The axis drift model is supported by the asymmetric lateral intensity profile of the SiO outflow. The axis drift rate is about 0.011 deg yr-1. The middle part of the northeastern outflow does not exactly follow the point symmetry because of the superposition of two different kinds of directional variability: the axis drift of the driving source and the deflection by a dense core. The axis drift model provides a good explanation for the large deflection angle of the northeastern outflow. Other H2 emission features around the IRAS 4 region are discussed briefly. Some of them are newly found outflows, and some are associated with outflows already known before.

  15. Impacts of pure shocks in the BHR71 bipolar outflow

    E-Print Network [OSTI]

    Gusdorf, Antoine; Anderl, Sibylle; Eisloeffel, Jochen; Codella, Claudio; Gomez-Ruiz, Arturo; Graf, Urs; Kristensen, Lars; Leurini, Silvia; Parise, Berengere; Requena-Torres, Migel; Ricken, Oliver; Guesten, Rolf

    2015-01-01T23:59:59.000Z

    During the formation of a star, material is ejected along powerful jets that impact the ambient material. This outflow regulates star formation by e.g. inducing turbulence and heating the surrounding gas. Understanding the associated shocks is therefore essential to the study of star formation. We present comparisons of shock models with CO, H2, and SiO observations in a 'pure' shock position in the BHR71 bipolar outflow. These comparisons provide an insight into the shock and pre-shock characteristics, and allow us to understand the energetic and chemical feedback of star formation on Galactic scales. New CO (Jup = 16, 11, 7, 6, 4, 3) observations from the shocked regions with the SOFIA and APEX telescopes are presented and combined with earlier H2 and SiO data (from the Spitzer and APEX telescopes). The integrated intensities are compared to a grid of models that were obtained from a magneto-hydrodynamical shock code which calculates the dynamical and chemical structure of these regions combined with a radi...

  16. Massive disk outflows mediated by extreme magnetic fields

    E-Print Network [OSTI]

    Shiber, Sagiv; Soker, Noam

    2015-01-01T23:59:59.000Z

    We argue that magnetic fields amplified within a very high accretion-rate disk around main sequence stars can lead to the formation of massive bipolar outflows that can remove most of the disk's mass and energy. This efficient directional removal of energy and mass allows the high accretion-rate disk to be built. We construct thick disks where the magnetic fields are amplified by an Alpha-Omega dynamo in the disk, bringing the fluctuating components of the magnetic field to be much stronger than the large-scale component. By examining the possible activity of the magnetic fields we conclude that main sequence stars can accrete mass at very high rates, up to 0.01Mo/yr for solar type stars, and up to 1Mo/yr for very massive stars. Such energetic outflows can account for the powering of some eruptive objects, such as merging main sequence stars, major eruptions of luminous blue variables, such as the Great Eruption of Eta Carinae, and other intermediate luminosity optical transients (ILOTs; Red Novae; Red Transi...

  17. Probing T Tauri Accretion and Outflow with 1 Micron Spectroscopy

    E-Print Network [OSTI]

    Suzan Edwards; William Fischer; Lynne Hillenbrand; John Kwan

    2006-04-01T23:59:59.000Z

    In a high dispersion 1 micron survey of 39 classical T Tauri stars veiling is detected in 80%, and He I 10830 and Pgamma line emission in 97% of the stars. On average, the 1 micron veiling exceeds the level expected from previously identified sources of excess emission, suggesting the presence of an additional contributor to accretion luminosity in the star-disk interface region. Strengths of both lines correlate with veiling, and at Pgamma there is a systematic progression in profile morphology with veiling. He I 10830 has an unprecedented sensitivity to inner winds, showing blueshifted absorption below the continuum in 71% of the CTTS compared to 0% at pgamma. This line is also sensitive to magnetospheric accretion flows, with redshifted absorption below the continuum found in 47% of the CTTS compared to 24% at Pgamma. The blueshifted absorption at 10830 shows considerable diversity in its breadth and penetration depth into the continuum, indicating that a range of inner wind conditions exist in accreting stars. We interpret the broadest and deepest blue absorptions as formed from scattering of the 1 micron continuum by outflowing gas whose full acceleration region envelopes the star, suggesting radial outflow from the star. In contrast, narrow blue absorption with a range of radial velocities more likely arises via scattering of the 1 micron continuum by a wind emerging from the inner disk. Both stellar and disk winds are accretion powered since neither is seen in non-accreting WTTS and among the CTTS helium strength correlates with veiling.

  18. Feedback from Protostellar Outflows in Star and Star Cluster Formation

    E-Print Network [OSTI]

    Christopher D. Matzner

    2000-07-13T23:59:59.000Z

    Magnetic stresses collimate protostellar winds into a common distribution of force with angle. Sweeping into the ambient medium, such winds drive bipolar molecular outflows whose properties are insensitive to the distribution of ambient gas and to the details of how the wind is launched, and how its intensity varies over time. Moreover, these properties are in accord with the commonly observed features of outflows. This model is simple enough to permit a quantitative study of the feedback effects from low-mass star formation. It predicts the rate at which star-forming gas is ejected by winds, and hence the efficiency with which stars form. Applied to individual star formation, it relates the stellar initial mass function to the distribution of pre-stellar cores. Applied to cluster formation, it indicates whether the resulting stellar system will remain gravitationally bound. Using the energy injection and mass ejection implied by this model, we investigate the dynamical evolution of a molecular clump as a stellar cluster forms within it. This depends critically on the rate at which turbulence decays: it may involve equilibrium star formation (slow decay), overstable oscillations, or collapse (fast decay).

  19. Filaments, Collapse and Outflows in Massive Star Formation

    E-Print Network [OSTI]

    Robi Banerjee; Ralph E. Pudritz

    2008-07-04T23:59:59.000Z

    We present results from our numerical simulations of collapsing massive molecular cloud cores. These numerical calculations show that massive stars assemble quickly with mass accretion rates exceeding 10^-3 Msol/yr and confirm that the mass accretion during the collapsing phase is much more efficient than predicted by selfsimilar collapse solutions, dM/dt ~ c^3/G. We find that during protostellar assembly out of a non-turbulent core, the mass accretion reaches 20 - 100 c^3/G. Furthermore, we explore the self-consistent structure of bipolar outflows that are produced in our three dimensional magnetized collapse simulations. These outflows produce cavities out of which radiation pressure can be released, thereby reducing the limitations on the final mass of massive stars formed by gravitational collapse. Additional enhancement of the mass accretion rate comes from accretion along filaments that are built up by supersonic turbulent motions. Our numerical calculations of collapsing turbulent cores result in mass accretion rates as high as 10^-2 Msol/yr.

  20. ULTRAFAST OUTFLOWS: GALAXY-SCALE ACTIVE GALACTIC NUCLEUS FEEDBACK

    SciTech Connect (OSTI)

    Wagner, A. Y.; Umemura, M. [Center for Computational Sciences, University of Tsukuba, 1-1-1 Tennodai, Tsukuba, Ibaraki, 305-8577 (Japan); Bicknell, G. V., E-mail: ayw@ccs.tsukuba.ac.jp [Research School of Astronomy and Astrophysics, Australian National University, ACT 2611 (Australia)

    2013-01-20T23:59:59.000Z

    We show, using global three-dimensional grid-based hydrodynamical simulations, that ultrafast outflows (UFOs) from active galactic nuclei (AGNs) result in considerable feedback of energy and momentum into the interstellar medium (ISM) of the host galaxy. The AGN wind interacts strongly with the inhomogeneous, two-phase ISM consisting of dense clouds embedded in a tenuous, hot, hydrostatic medium. The outflow floods through the intercloud channels, sweeps up the hot ISM, and ablates and disperses the dense clouds. The momentum of the UFO is primarily transferred to the dense clouds via the ram pressure in the channel flow, and the wind-blown bubble evolves in the energy-driven regime. Any dependence on UFO opening angle disappears after the first interaction with obstructing clouds. On kpc scales, therefore, feedback by UFOs operates similarly to feedback by relativistic AGN jets. Negative feedback is significantly stronger if clouds are distributed spherically rather than in a disk. In the latter case, the turbulent backflow of the wind drives mass inflow toward the central black hole. Considering the common occurrence of UFOs in AGNs, they are likely to be important in the cosmological feedback cycles of galaxy formation.

  1. The Water Vapor Abundance in Orion KL Outflows

    E-Print Network [OSTI]

    J. Cernicharo; J. R. Goicoechea; F. Daniel; M. R. Lerate; M. J. Barlow; B. M. Swinyard; E. van Dishoeck; T. L. Lim; S. Viti; J. Yates

    2006-08-16T23:59:59.000Z

    We present the detection and modeling of more than 70 far-IR pure rotational lines of water vapor, including the 18O and 17O isotopologues, towards Orion KL. Observations were performed with the Long Wavelength Spectrometer Fabry-Perot (LWS/FP; R~6800-9700) on board the Infrared Space Observatory (ISO) between ~43 and ~197 um. The water line profiles evolve from P-Cygni type profiles (even for the H2O18 lines) to pure emission at wavelengths above ~100 um. We find that most of the water emission/absorption arises from an extended flow of gas expanding at 25+-5 kms^-1. Non-local radiative transfer models show that much of the water excitation and line profile formation is driven by the dust continuum emission. The derived beam averaged water abundance is 2-3x10^-5. The inferred gas temperature Tk=80-100 K suggests that: (i) water could have been formed in the "plateau" by gas phase neutral-neutral reactions with activation barriers if the gas was previously heated (e.g. by shocks) to >500 K and/or (ii) H2O formation in the outflow is dominated by in-situ evaporation of grain water-ice mantles and/or (iii) H2O was formed in the innermost and warmer regions (e.g. the hot core) and was swept up in ~1000 yr, the dynamical timescale of the outflow.

  2. Transport pathways for Asian pollution outflow over the Pacific: Interannual and seasonal variations

    E-Print Network [OSTI]

    Liu, Hongyu

    is frontal lifting ahead of southeastward-moving cold fronts (the leading edge of cold surges) and transport with the cold fronts to promote the transport of Chinese pollution to the free troposphere. Outflow of seasonalTransport pathways for Asian pollution outflow over the Pacific: Interannual and seasonal

  3. Acid Fracture and Fracture Conductivity Study of Field Rock Samples 

    E-Print Network [OSTI]

    Underwood, Jarrod

    2013-11-15T23:59:59.000Z

    carbonate reservoir were labeled A through F to protect proprietary information included in this research. A 2% potassium chloride solution was used for the acid system and fracture conductivity measurements to prevent clay swelling. Injection temperature...

  4. Optimization of fracture treatment designs

    E-Print Network [OSTI]

    Rueda, Jose Ignacio

    1992-01-01T23:59:59.000Z

    using the type curves published by Holditch et al2O. n f H r lic Fracture Pro a ation imula or In 1955, the first model to simulate the propagation of a vertical hydraulic fracture was developed by Khristianovitch and Zheltov O (K-Z model). This two... . . . . 93 97 LIST OF TABLES Table Page 5. I Reservoir and well data for base case example 54 5. 2 Fracture design data for base case example . 54 5. 3 Economic data for base case example . . 54 5. 4 Comparison of the methods used in STIMOP and LPOP...

  5. 4D imaging of fracturing in organic-rich shales during heating

    SciTech Connect (OSTI)

    Maya Kobchenko; Hamed Panahi; François Renard; Dag K. Dysthe; Anders Malthe-Sørenssen; Adriano Mazzini; Julien Scheibert1; Bjørn Jamtveit; Paul Meakin

    2011-12-01T23:59:59.000Z

    To better understand the mechanisms of fracture pattern development and fluid escape in low permeability rocks, we performed time-resolved in situ X-ray tomography imaging to investigate the processes that occur during the slow heating (from 60 to 400 C) of organic-rich Green River shale. At about 350 C cracks nucleated in the sample, and as the temperature continued to increase, these cracks propagated parallel to shale bedding and coalesced, thus cutting across the sample. Thermogravimetry and gas chromatography revealed that the fracturing occurring at {approx}350 C was associated with significant mass loss and release of light hydrocarbons generated by the decomposition of immature organic matter. Kerogen decomposition is thought to cause an internal pressure build up sufficient to form cracks in the shale, thus providing pathways for the outgoing hydrocarbons. We show that a 2D numerical model based on this idea qualitatively reproduces the experimentally observed dynamics of crack nucleation, growth and coalescence, as well as the irregular outlines of the cracks. Our results provide a new description of fracture pattern formation in low permeability shales.

  6. Analysis of a multiphase, porous-flow imbibition experiment in fractured volcanic tuff

    SciTech Connect (OSTI)

    Eaton, R.R.; Bixler, N.E.

    1986-12-31T23:59:59.000Z

    A sub-meter-scale imbibition experiment has been analyzed using a finite element, multiphase-flow code. In the experiment, an initially dry cylindrical core of fractured volcanic tuff was saturated by contacting the ends with pressurized water. Our model discretely accounts for three primary fractures that may be present in the core, as indicated by measurements of porosity and saturation. We show that vapor transport has a small (less than 5%) effect on the speed of the wetting front. By using experimental results to estimate apparent spatial variations in permeability along the core, good agreement with measured, transient, saturation data was achieved. The sensitivity of predicted transient wetting fronts to permeability data indicates a need for more extensive measurements. We conclude that it will be difficult to characterize an entire repository - where inhomogeneities due to variations in matrix and fracture properties are not well known - solely from the results of sub-meter-scale laboratory testing and deterministic modeling. 16 refs., 8 figs., 1 tab.

  7. Characterization and significance of a stylolitic fracture system determined from horizontal core and borehole imaging data, Hanifa Reservoir, Abqaiq Field (SA)

    SciTech Connect (OSTI)

    Luthy, S.T.; Grover, G. [Saudi Aramco, Dhahran (Saudi Arabia); Wiltse, E. [Schlumberger, Al-Khobar (Saudi Arabia)

    1995-08-01T23:59:59.000Z

    The Hanifa reservoir at Abqaiq Field, eastern Saudi Arabia, consists of microporous (up to 30% porosity) lime mudstones with low matrix permeability (< 10 md). SEM imagery reveals a crystal framework texture of micro-rhombic calcite crystals with 2-5 {mu}m-sized intercrystalline pore spaces. Fluid transmissibility was preliminarily identified as via fractures as indicated by no stratigraphic predictability to fluid flow, high flow over thin stratigraphic intervals, little relationship between high flow and high porosity intervals, large disparity between core Kh and well-test Kh, and observation offractures in cores and borehole imaging logs front horizontal Hanifa wells. Integration of descriptions from over 4000 fractures observed in borehole images together with descriptions of over 500 fractures identified from vertica1 and horizontal cores has resulted in further characterization of the fracture system. The fractures are open to partially-open, with an east-to northeast orientation, and they cluster in low porosity zones which are characterized by intense stylolitization. These sub-parallel, nearly vertical, discontinuous fractures terminate at stylolites, or pinchout locally into tight carbonate matrix, and contain appreciable amounts of dead oil and calcite cement. In zones of particularly intense stylolitization, fracturing may be locally pervasive, giving the rock a brecciated appearance. Together, the stylolites and stylolite-related fractures form the primary permeability system ofthe Hanifa reservoir. This fracture system architecture is critical to understanding the production characteristics of the reservoir, which include anomalously high fluid flow in low porosity zones or transition zones between high and low porosity, radial flow behavior from well tests, smaller than expected differences in well productivity between vertical and horizontal wells, and limited injection water breakthrough.

  8. NEW AND NOVEL FRACTURE STIMULATION TECHNOLOGIES FOR THE REVITALIZATION OF EXISTING GAS STORAGE WELLS

    SciTech Connect (OSTI)

    Unknown

    1999-12-01T23:59:59.000Z

    Gas storage wells are prone to continued deliverability loss at a reported average rate of 5% per annum (in the U.S.). This is a result of formation damage due to the introduction of foreign materials during gas injection, scale deposition and/or fines mobilization during gas withdrawal, and even the formation and growth of bacteria. As a means to bypass this damage and sustain/enhance well deliverability, several new and novel fracture stimulation technologies were tested in gas storage fields across the U.S. as part of a joint U.S. Department of Energy and Gas Research Institute R&D program. These new technologies include tip-screenout fracturing, hydraulic fracturing with liquid CO{sub 2} and proppant, extreme overbalance fracturing, and high-energy gas fracturing. Each of these technologies in some way address concerns with fracturing on the part of gas storage operators, such as fracture height growth, high permeability formations, and fluid sensitivity. Given the historical operator concerns over hydraulic fracturing in gas storage wells, plus the many other unique characteristics and resulting stimulation requirements of gas storage reservoirs (which are described later), the specific objective of this project was to identify new and novel fracture stimulation technologies that directly address these concerns and requirements, and to demonstrate/test their potential application in gas storage wells in various reservoir settings across the country. To compare these new methods to current industry deliverability enhancement norms in a consistent manner, their application was evaluated on a cost per unit of added deliverability basis, using typical non-fracturing well remediation methods as the benchmark and considering both short-term and long-term deliverability enhancement results. Based on the success (or lack thereof) of the various fracture stimulation technologies investigated, guidelines for their application, design and implementation have been developed. A final research objective was to effectively deploy the knowledge and experience gained from the project to the gas storage industry at-large.

  9. Neutrino Interactions in the Outflow from Gamma-Ray Burst Accretion Disks

    E-Print Network [OSTI]

    R. Surman; G. C. McLaughlin

    2004-07-09T23:59:59.000Z

    We examine the composition of matter as it flows away from gamma ray burst accretion disks, in order to determine what sort of nucleosynthesis may occur. Since there is a large flux of neutrinos leaving the surface of the disk, the electron fraction of the outflowing material will change due to charged current neutrino interactions. We calculate the electron fraction in the wind using detailed neutrino fluxes from every point on the disk and study a range of trajectories and outflow conditions for several different accretion disk models. We find that low electron fractions, conducive to making r-process elements, only appear in outflows from disks with high accretion rates that have a significant region both of trapped neutrinos and antineutrinos. Disks with lower accretion rates that have only a significant region of trapped neutrinos can have outflows with very high electron fractions, whereas the lowest accretion rate disks with little trapping have outflow electrons fractions of closer to one half.

  10. Characterization and estimation of permeability correlation structure from performance data

    SciTech Connect (OSTI)

    Ershaghi, I.; Al-Qahtani, M. [Univ. of Southern California, Los Angeles, CA (United States)

    1997-08-01T23:59:59.000Z

    In this study, the influence of permeability structure and correlation length on the system effective permeability and recovery factors of 2-D cross-sectional reservoir models, under waterflood, is investigated. Reservoirs with identical statistical representation of permeability attributes are shown to exhibit different system effective permeability and production characteristics which can be expressed by a mean and variance. The mean and variance are shown to be significantly influenced by the correlation length. Detailed quantification of the influence of horizontal and vertical correlation lengths for different permeability distributions is presented. The effect of capillary pressure, P{sub c1} on the production characteristics and saturation profiles at different correlation lengths is also investigated. It is observed that neglecting P{sub c} causes considerable error at large horizontal and short vertical correlation lengths. The effect of using constant as opposed to variable relative permeability attributes is also investigated at different correlation lengths. Next we studied the influence of correlation anisotropy in 2-D reservoir models. For a reservoir under five-spot waterflood pattern, it is shown that the ratios of breakthrough times and recovery factors of the wells in each direction of correlation are greatly influenced by the degree of anisotropy. In fully developed fields, performance data can aid in the recognition of reservoir anisotropy. Finally, a procedure for estimating the spatial correlation length from performance data is presented. Both the production performance data and the system`s effective permeability are required in estimating the correlation length.

  11. IMPACT OF CAPILLARY AND BOND NUMBERS ON RELATIVE PERMEABILITY

    SciTech Connect (OSTI)

    Kishore K. Mohanty

    2002-09-30T23:59:59.000Z

    Recovery and recovery rate of oil, gas and condensates depend crucially on their relative permeability. Relative permeability in turn depends on the pore structure, wettability and flooding conditions, which can be represented by a set of dimensionless groups including capillary and bond numbers. The effect of flooding conditions on drainage relative permeabilities is not well understood and is the overall goal of this project. This project has three specific objectives: to improve the centrifuge relative permeability method, to measure capillary and bond number effects experimentally, and to develop a pore network model for multiphase flows. A centrifuge has been built that can accommodate high pressure core holders and x-ray saturation monitoring. The centrifuge core holders can operate at a pore pressure of 6.9 MPa (1000 psi) and an overburden pressure of 17 MPa (2500 psi). The effect of capillary number on residual saturation and relative permeability in drainage flow has been measured. A pore network model has been developed to study the effect of capillary numbers and viscosity ratio on drainage relative permeability. Capillary and Reynolds number dependence of gas-condensate flow has been studied during well testing. A method has been developed to estimate relative permeability parameters from gas-condensate well test data.

  12. Nucleosynthesis in the outflows associated with accretion disks of Type II collapsars

    E-Print Network [OSTI]

    Indrani Banerjee; Banibrata Mukhopadhyay

    2013-09-04T23:59:59.000Z

    We investigate nucleosynthesis inside the outflows from gamma-ray burst (GRB) accretion disks formed by the Type II collapsars. In these collapsars, massive stars undergo core collapse to form a proto-neutron star initially and a mild supernova explosion is driven. The supernova ejecta lack momentum and subsequently this newly formed neutron star gets transformed to a stellar mass black hole via massive fallback. The hydrodynamics and the nucleosynthesis in these accretion disks has been studied extensively in the past. Several heavy elements are synthesized in the disk and much of these heavy elements are ejected from the disk via winds and outflows. We study nucleosynthesis in the outflows launched from these disks by using an adiabatic, spherically expanding outflow model, to understand which of these elements thus synthesized in the disk survive in the outflow. While studying this we find that many new elements like isotopes of titanium, copper, zinc etc. are present in the outflows. 56Ni is abundantly synthesized in most of the cases in the outflow which implies that the outflows from these disks in a majority of cases will lead to an observable supernova explosion. It is mainly present when outflow is considered from the He-rich, 56Ni/54Fe rich zones of the disks. However, outflow from the Si-rich zone of the disk remains rich in silicon. Although, emission lines of many of these heavy elements have been observed in the X-ray afterglows of several GRBs by Chandra, BeppoSAX, XMM-Newton etc., Swift seems to have not detected these lines yet.

  13. NUCLEOSYNTHESIS IN THE OUTFLOWS ASSOCIATED WITH ACCRETION DISKS OF TYPE II COLLAPSARS

    SciTech Connect (OSTI)

    Banerjee, Indrani; Mukhopadhyay, Banibrata, E-mail: indrani@physics.iisc.ernet.in, E-mail: bm@physics.iisc.ernet.in [Department of Physics, Indian Institute of Science, Bangalore 560 012 (India)

    2013-11-20T23:59:59.000Z

    We investigate nucleosynthesis inside the outflows from gamma-ray burst (GRB) accretion disks formed by the Type II collapsars. In these collapsars, massive stars undergo core collapse to form a proto-neutron star initially, and a mild supernova (SN) explosion is driven. The SN ejecta lack momentum, and subsequently this newly formed neutron star gets transformed to a stellar mass black hole via massive fallback. The hydrodynamics and the nucleosynthesis in these accretion disks have been studied extensively in the past. Several heavy elements are synthesized in the disk, and much of these heavy elements are ejected from the disk via winds and outflows. We study nucleosynthesis in the outflows launched from these disks by using an adiabatic, spherically expanding outflow model, to understand which of these elements thus synthesized in the disk survive in the outflow. While studying this, we find that many new elements like isotopes of titanium, copper, zinc, etc., are present in the outflows. {sup 56}Ni is abundantly synthesized in most of the cases in the outflow, which implies that the outflows from these disks in a majority of cases will lead to an observable SN explosion. It is mainly present when outflow is considered from the He-rich, {sup 56}Ni/{sup 54}Fe-rich zones of the disks. However, outflow from the Si-rich zone of the disk remains rich in silicon. Although emission lines of many of these heavy elements have been observed in the X-ray afterglows of several GRBs by Chandra, BeppoSAX, XMM-Newton, etc., Swift seems to have not yet detected these lines.

  14. Fracture of aluminum naval structures

    E-Print Network [OSTI]

    Galanis, Konstantinos, 1970-

    2007-01-01T23:59:59.000Z

    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. ...

  15. Sensitivity analysis of fracture scattering

    E-Print Network [OSTI]

    Fang, Xinding, S.M. Massachusetts Institute of Technology

    2010-01-01T23:59:59.000Z

    We use a 2-D finite difference method to numerically calculate the seismic response of a single finite fracture in a homogeneous media. In our experiments, we use a point explosive source and ignore the free surface effect, ...

  16. FRACTURE STIMULATION IN ENHANCED GEOTHERMAL

    E-Print Network [OSTI]

    Stanford University

    FRACTURE STIMULATION IN ENHANCED GEOTHERMAL SYSTEMS A REPORT SUBMITTED TO THE DEPARTMENT OF ENERGY (Principal Advisor) #12;#12;v Abstract Enhanced Geothermal Systems (EGS) are geothermal reservoirs formed

  17. Seismic anisotropy of fractured rock

    E-Print Network [OSTI]

    M. Schoenberg, C. M. Sayers

    2000-02-18T23:59:59.000Z

    of seismic anisotropy to determine the orientation of fracture sets is of ... this assumption of noninteraction does not imply that the ... conventional (2-subscript) condensed 6 x 6 matrix notation,. 11. 6, while ... have simple physical interpretations.

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

    SciTech Connect (OSTI)

    NONE

    1997-12-31T23:59:59.000Z

    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.

  19. The determination of permeability using a pulse decay technique

    E-Print Network [OSTI]

    Rowe, William Charlton

    1985-01-01T23:59:59.000Z

    pressures from 0 to 15, 000 psi and a maximum pore pressure of 16 psi. The core samples studied had permeabilities rang1ng from 40 to 319 md. They concluded that permeability of sandstone decreases with increase in overburden pressure. The major reduct1...on occurred over the range of 0 to 3000 psi overburden pressure. At 3000 psi overburden pressure, permeabilities ranged from 59 to 89 per cent of their orig1nal unstressed cond1tions, as illustrated in F1g. l. In 1969, Ritch and Kozik4 reported...

  20. Estimation of fracture compliance from tubewaves generated at a fracture intersecting a borehole

    E-Print Network [OSTI]

    Bakku, Sudhish Kumar

    2011-01-01T23:59:59.000Z

    Understanding fracture compliance is important for characterizing fracture networks and for inferring fluid flow in the subsurface. In an attempt to estimate fracture compliance in the field, we developed a new model to ...

  1. Powerful Outflows and Feedback from Active Galactic Nuclei

    E-Print Network [OSTI]

    King, Andrew

    2015-01-01T23:59:59.000Z

    Active Galactic Nuclei (AGN) represent the growth phases of the supermassive black holes in the center of almost every galaxy. Powerful, highly ionized winds, with velocities $\\sim 0.1- 0.2c$ are a common feature in X--ray spectra of luminous AGN, offering a plausible physical origin for the well known connections between the hole and properties of its host. Observability constraints suggest that the winds must be episodic, and detectable only for a few percent of their lifetimes. The most powerful wind feedback, establishing the $M -\\sigma$ relation, is probably not directly observable at all. The $M - \\sigma$ relation signals a global change in the nature of AGN feedback. At black hole masses below $M-\\sigma$ feedback is confined to the immediate vicinity of the hole. At the $M-\\sigma$ mass it becomes much more energetic and widespread, and can drive away much of the bulge gas as a fast molecular outflow.

  2. Stochastic Modeling of a Fracture Network in a Hydraulically Fractured Shale-Gas Reservoir

    E-Print Network [OSTI]

    Mhiri, Adnene

    2014-08-10T23:59:59.000Z

    : ? Uniform distribution of heterogeneities that cause a variation of geomechanical properties such as: — In-situ stress — Fracture initiation pressure — Elastic moduli (Shear modulus and Poisson’s ratio) ? No interaction with natural fractures: — Natural... that are dynamically created due to the change in the geomechanical properties in the vicinity of the primary fracture these are referred to as secondary fractures and are thought to be orthogonal to primary fractures. ? The fractures that originate due...

  3. Integrated seismic study of naturally fractured tight gas reservoirs. Technical progress report, October 1, 1992--December 31, 1992

    SciTech Connect (OSTI)

    Nur, A.

    1993-01-21T23:59:59.000Z

    This was the fifth quarter of the contract. During this quarter we (1) got approval for the NEPA requirements related to the field work, (2) placed the subcontract for the field data acquisition, (3) completed the field work, and (4) began processing the seismic data. As already reported, the field data acquisition was at Acomo`s Powder River Basin site in southeast Wyoming. This is a low permeability fractured site, with both gas and oil present. The reservoir is highly compartmentalized, due to the low permeability, with the fractures providing the only practical drainage paths for production. The two formations of interest are: The Niobrara: a fractured shale and limey shale to chalk, which is a reservoir rock, but also its own source rock. The Frontier: a tight sandstone lying directly below the Niobrara, brought into contact with it by an unconformity. The fractures are thought to lie in a roughly northwest-southeast trend, along the strike of a flexure, which forms one of the boundaries of the basin.

  4. Integrated seismic study of naturally fractured tight gas reservoirs. Technical progress report, January 1, 1993--March 31, 1993

    SciTech Connect (OSTI)

    Mavko, G.; Nur, A.

    1993-04-26T23:59:59.000Z

    During this quarter we (1) received the last of the field tapes and survey information for the seismic field data acquisition which was finished at the very end of the previous quarter, (2) began the large task of processing the seismic data, (3) collected well logs and other informination to aid in the interpretation, and (4) initiated some seismic modeling studies. As already reported, the field data acquisition was at Amoco`s Powder River Basin site in southeast Wyoming. This is a low permeability fractured site, with both gas and oil present. The reservoir is highly compartmentalized, due to the low permeability, with the fractures providing the only practical drainage paths for production. The two formations of interest are: The Niobrara: a fractured shale and limey shale to chalk, which is a reservoir rock, but also its own source rock. The Frontier: a tight sandstone lying directly below the Niobrara, brought into contact with it by an unconformity. The fractures are thought to lie in a roughly northwest-southeast trend, along the strike of a flexure, which forms one of the boundaries of the basin.

  5. INTERPRETATION OF A HYDRAULIC FRACTURING EXPERIMENT, MONTICELLO, SOUTH CAROLINA

    E-Print Network [OSTI]

    Narasimhan, T.N.

    2014-01-01T23:59:59.000Z

    Letters INTERPRETATION OF A HYDRAULIC FRACTURING EXPERIMENT,12091 INTERPRETATION OF A HYDRAULIC FRACTURING EXPERIMENT,transient data from a hydraulic fracturing experiment have

  6. Elastic properties of saturated porous rocks with aligned fractures

    E-Print Network [OSTI]

    2003-12-02T23:59:59.000Z

    This unexpected result is caused by the wave-induced flow of fluids between pores and fractures. ..... For non-fractured rock setting fracture weaknesses. DN and ...

  7. GMINC - A MESH GENERATOR FOR FLOW SIMULATIONS IN FRACTURED RESERVOIRS

    E-Print Network [OSTI]

    Pruess, K.

    2010-01-01T23:59:59.000Z

    Flow in Naturally Fractured Reservoirs, Society of Petroleumfor Naturally Fractured Reservoirs, paper SPE-11688,Determining Naturally Fractured Reservoir Properties by Well

  8. Analysis of flow behavior in fractured lithophysal reservoirs

    E-Print Network [OSTI]

    Liu, Jianchun; Bodvarsson, G.S.; Wu, Yu-Shu

    2002-01-01T23:59:59.000Z

    R. , 1980. Naturally Fractured Reservoirs, Petroleum, Tulsa,bounded naturally fractured reservoirs. Soc. Pet. Eng. J.test in a naturally fractured reservoir. J. Pet. Tech. 1295–

  9. Tracer Testing for Estimating Heat Transfer Area in Fractured Reservoirs

    E-Print Network [OSTI]

    Pruess, Karsten; van Heel, Ton; Shan, Chao

    2004-01-01T23:59:59.000Z

    Heat Flow in Fractured Reservoirs, SPE Advanced TechnologyTransfer Area in Fractured Reservoirs Karsten Pruess 1 , Tonbehavior arises in fractured reservoirs. As cold injected

  10. asymmetric hydraulic fracture: Topics by E-print Network

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

    from the fractured shale 17 RPSEA UNCONVENTIONAL GAS CONFERENCE 2012: Geology, the Environment, Hydraulic Fracturing Engineering Websites Summary: Fracturing Experiment Overview...

  11. advanced hydraulic fracturing: Topics by E-print Network

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

    from the fractured shale 18 RPSEA UNCONVENTIONAL GAS CONFERENCE 2012: Geology, the Environment, Hydraulic Fracturing Engineering Websites Summary: Fracturing Experiment Overview...

  12. Multiwell experiment: Fracturing experiments

    SciTech Connect (OSTI)

    Warpinski, N.R.; Sattler, A.R.; Branagan, P.T.; Cipolla, C.

    1987-01-01T23:59:59.000Z

    Because of the complexity of the stimulation, no conventional analyses were useful, so we decided to concentrate on the minifrac to provide important fracture parameters. The minifrac was conducted in an identical manner to the pressure-up and pad stages of the stimulation. Figure 1 shows two initial pressure-history match calculations that were performed to model the minifrac. We found that the pressure behavior could not be matched with any normal behavior. Examining the field pressure data, we see that the interesting feature is the sudden flattening in the pressure at a level 1050 psi above the closure stress during pumping and the rapid drop to this same level at shut-in, after which the pressure decreases much more slowly. We first tried to match this behavior using enhanced height growth. While height growth can flatten the pressure during pumping, it also causes a very slow pressure decline at shut-in. We also tried additional leakoff height as height grew, but this could not flatten the pressure as much as needed. Finally, we tried an accelerated leakoff condition above 1050 psi. We did this by increasing the leakoff coefficient by a constant factor above some threshold value. To keep the results smooth and code convergent, we actually linearly phased in the increased leakoff between 1000 and 1100 psi. The final result of these calculations is shown in Figure 2; a factor of 50 increase in the leakoff coefficient was required to match the data for pressures above 1050 psi.

  13. Hydrogen permeable protective coating for a catalytic surface

    DOE Patents [OSTI]

    Liu, Ping (Irvine, CA); Tracy, C. Edwin (Golen, CO); Pitts, J. Roland (Lakewood, CO); Lee, Se-Hee (Lakewood, CO)

    2007-06-19T23:59:59.000Z

    A protective coating for a surface comprising a layer permeable to hydrogen, said coating being deposited on a catalyst layer; wherein the catalytic activity of the catalyst layer is preserved.

  14. altered permeability states: Topics by E-print Network

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

    compounds: The effect of structure and pH on Caco-2 cell permeability University of Kansas - KU ScholarWorks Summary: A tetrazole ring is often used in drug discovery as a...

  15. Extended correlations of porosity, permeability, and formation resistivity factor

    E-Print Network [OSTI]

    Ellis, Keith Wade

    1987-01-01T23:59:59.000Z

    obtained through a literature search, and the remainder were obtained through donations by Shell and Tenneco. The complete data set consists of permeability, porosity and formation factor measurements for twenty formations. Of the twenty data sets, seven...

  16. Experimental Study on Rock Deformation and Permeability Variation

    E-Print Network [OSTI]

    Ding, Jihui

    2013-08-01T23:59:59.000Z

    The development of a petroleum reservoir would inevitably induce a rearrangement of the in-situ stress field. The rearrangement of the stress field would then bring about a deformation of the reservoir rock and a change of the permeability...

  17. Combined permeable pavement and ground source heat pump systems 

    E-Print Network [OSTI]

    Grabowiecki, Piotr

    2010-01-01T23:59:59.000Z

    The PhD thesis focuses on the performance assessment of permeable pavement systems incorporating ground source heat pumps (GSHP). The relatively high variability of temperature in these systems allows for the survival of pathogenic organisms within...

  18. Preliminary relative permeability estimates of methanehydrate-bearing sand

    SciTech Connect (OSTI)

    Seol, Yongkoo; Kneafsey, Timothy J.; Tomutsa, Liviu; Moridis,George J.

    2006-05-08T23:59:59.000Z

    The relative permeability to fluids in hydrate-bearing sediments is an important parameter for predicting natural gas production from gas hydrate reservoirs. We estimated the relative permeability parameters (van Genuchten alpha and m) in a hydrate-bearing sand by means of inverse modeling, which involved matching water saturation predictions with observations from a controlled waterflood experiment. We used x-ray computed tomography (CT) scanning to determine both the porosity and the hydrate and aqueous phase saturation distributions in the samples. X-ray CT images showed that hydrate and aqueous phase saturations are non-uniform, and that water flow focuses in regions of lower hydrate saturation. The relative permeability parameters were estimated at two locations in each sample. Differences between the estimated parameter sets at the two locations were attributed to heterogeneity in the hydrate saturation. Better estimates of the relative permeability parameters require further refinement of the experimental design, and better description of heterogeneity in the numerical inversions.

  19. Permeability, Resistivity and Strength of Fouled Railroad Ballast

    E-Print Network [OSTI]

    Rahman, A. J.

    2013-08-31T23:59:59.000Z

    particles between the ballast particles; therefore, permeability and resistivity were also correlated. The strength properties of clean and fouled ballast were also evaluated using large direct shear box and modified direct shear box (extension in height...

  20. Stress-dependent permeability on tight gas reservoirs 

    E-Print Network [OSTI]

    Rodriguez, Cesar Alexander

    2005-02-17T23:59:59.000Z

    People in the oil and gas industry sometimes do not consider pressure-dependent permeability in reservoir performance calculations. It basically happens due to lack of lab data to determine level of dependency. This thesis ...

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

    E-Print Network [OSTI]

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

    2000-01-01T23:59:59.000Z

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

  2. Variability of the NGC 1333 IRAS 4A Outflow: Molecular Hydrogen and Silicon Monoxide Images

    E-Print Network [OSTI]

    Choi, M; Hayashi, M; Motohara, K; Pak, S; Pyo, T S; Choi, Minho; Hodapp, Klaus W.; Hayashi, Masahiko; Motohara, Kentaro; Pak, Soojong; Pyo, Tae-Soo

    2006-01-01T23:59:59.000Z

    The NGC 1333 region was observed in the H2 1-0 S(1) line. The H2 images cover a 5' x 7' region around IRAS 4. Numerous H2 emission features were detected. The northeast-southwest bipolar outflow driven by IRAS 4A was studied by combining the H2 images with SiO maps published previously. The SiO-H2 outflows are continuous on the southwestern side but show a gap on the northeastern side. The southwestern outflow lobe curves smoothly, and the position angle increases with the distance from the driving source. The base and the outer tip of the northeastern outflow lobe are located at positions opposite to the corresponding parts of the southwestern lobe. This point-symmetry suggests that the outflow axis may be drifting or precessing clockwise in the plane of the sky and that the cause of the axis drift may be intrinsic to the outflow engine. The axis drift model is supported by the asymmetric lateral intensity profile of the SiO outflow. The axis drift rate is about 0.011 deg yr-1. The middle part of the northea...

  3. Validity and limitations of gas-drive relative permeability measurement

    E-Print Network [OSTI]

    Gupta, Anand Kumar

    1971-01-01T23:59:59.000Z

    VALIDITY AND LIMITATIONS OF GAS-DRIVE RELA TI VE PERMEABILITY MEASUREMEN T A Thesis by ANAND KUMAR GUPTA Submitted to the Graduate College of Texas ARM University in partial fulfillxnent of the requirement for the degree of MASTER Ok SCIENCE... August, 1971 Major Subject: Petroleum Engineering VALIDITY AND LIMITATIONS OF GAS-DRIVE RELATIVE PERMEABILITY MEASUREMENT A Thesis by ANAND KUMAR GUPTA Approved as to style and content by: ( airman of Committee) ber) Head of Department) (Member...

  4. Water permeability and microstructure of three old concretes

    SciTech Connect (OSTI)

    Hearn, N.; Detwiler, R.J.; Sframeli, C. (Univ. of Toronto, Ontario (Canada). Dept. of Civil Engineering)

    1994-01-01T23:59:59.000Z

    Measurement of the permeability of concrete to water is complicated by the self-sealing phenomenon, the progressive reduction of flow during the test. Many researchers have attributed self sealing to the hydration of previously unreacted cement on exposure to water. This paper describes permeability tests on concretes continuously hydrated for 26 years. Backscattered electron images show that virtually no unhydrated cement remains in these specimens, yet they exhibit self-sealing behavior.

  5. Investigation of the rate sensitivity of pseudo relative permeabilities

    E-Print Network [OSTI]

    Brittain, Charles Finney

    1986-01-01T23:59:59.000Z

    of hypothetical reservoir stratifications were considered. Cross-sectional simulation runs were made using each stratification case for a range of waterflood injection rates and endpoint mobility ratios. Dynamic pseudo relative permeabilities were calculated... , These dynamic pseudo relative permeabilities were developed for those reservoirs that do not satisfy the assumptions of the vertical equilibrium or viscous-dominated pKr models. For waterflooding a stratified oil reservoir, fluid flow rate (velocity...

  6. A SEARCH FOR 95 GHz CLASS I METHANOL MASERS IN MOLECULAR OUTFLOWS

    SciTech Connect (OSTI)

    Gan, Cong-Gui; Chen, Xi; Shen, Zhi-Qiang [Key Laboratory for Research in Galaxies and Cosmology, Shanghai Astronomical Observatory, Chinese Academy of Sciences, 80 Nandan RD, Shanghai 200030 (China)] [Key Laboratory for Research in Galaxies and Cosmology, Shanghai Astronomical Observatory, Chinese Academy of Sciences, 80 Nandan RD, Shanghai 200030 (China); Xu, Ye; Ju, Bing-Gang, E-mail: cggan@shao.ac.cn [Key Laboratory of Radio Astronomy, Chinese Academy of Sciences (China)] [Key Laboratory of Radio Astronomy, Chinese Academy of Sciences (China)

    2013-01-20T23:59:59.000Z

    We have observed a sample of 288 molecular outflow sources including 123 high-mass and 165 low-mass sources in order to search for class I methanol masers at the 95 GHz transition and to investigate the relationship between outflow characteristics and class I methanol maser emission with the Purple Mountain Observatory 13.7 m radio telescope. Our survey detected 62 sources with 95 GHz methanol masers above a 3{sigma} detection limit, which includes 47 high-mass sources and 15 low-mass sources. Therefore, the detection rate is 38% for high-mass outflow sources and 9% for low-mass outflow sources, suggesting that class I methanol masers are relatively easily excited in high-mass sources. There are 37 newly detected 95 GHz methanol masers (including 27 high-mass and 10 low-mass sources), 19 of which are newly identified (i.e., first identification) class I methanol masers (including 13 high-mass and 6 low-mass sources). A statistical analysis of the distributions of maser detections with the outflow parameters reveals that the maser detection efficiency increases with the outflow properties (e.g., mass, momentum, kinetic energy, mechanical luminosity of outflows, etc.). Systematic investigations of the relationships between the intrinsic luminosity of methanol masers and the outflow properties (including mass, momentum, kinetic energy, bolometric luminosity, and mass-loss rate of the central stellar sources) indicate a positive correlation. This further supports the theory that class I methanol masers are collisionally pumped and associated with shocks when outflows interact with the surrounding ambient medium.

  7. Parsec-Scale Herbig-Haro Outflows from Intermediate Mass Stars

    E-Print Network [OSTI]

    Fiona McGroarty; Tom Ray; John Bally

    2003-11-04T23:59:59.000Z

    While there are many parsec-scale Herbig-Haro (HH) outflows known to be driven by low-mass young stars, few are associated with their intermediate mass counterparts. Here we present the discovery of five such bipolar outflows. Of these, LkHalpha 198, 1548C27 IRS1, LkHalpha 233 and LkHalpha 234 were previously known to possess small-scale HH flows, while no such activity was observed before near IRAS 19395+2313. The largest of the newly discovered outflows are seen in the vicinity of LkHalpha 234 and 1548C27 IRS1, and stretch (in projection) 8pc and 7.5pc respectively. LkHalpha 233 which was previously known to power a spectroscopically detected small-scale (< 10'') jet is now seen to drive a 3pc outflow and LkHalpha 198 is shown here to power a 2pc outflow. Two HH objects in the vicinity of IRAS 19395+2313 lead us to suggest that it may also be responsible for a 5pc outflow. In total, 27 new HH objects/complexes were discovered. Examination of these parsec-scale outflows show that they have similar lengths, morphologies, and dynamical timescales as those from low-mass sources. Many appear to have blown out of the parent cloud, suggesting that their total lengths are much greater than optically observed. The degree of collimation of these outflows is similar to those from low-mass sources suggesting that the transition to more poorly-collimated outflows must occur at higher masses than the sources observed here.

  8. FLOW CHARACTERISTICS AND RELATIVE PERMEABILITY FUNCTIONS FOR TWO

    E-Print Network [OSTI]

    Stanford University

    i s t i c s f o r a fractured geothermal reservoir have been obtained by m d e l l i n g the system fractured geothermal reservoirs. ii #12;. #12;TABLE OF CONTENTS -- ABSTRACT RESERVOIRS FROM A ONE DIMENSIONAL THERMODYNAMIC MODEL Anthony J. Menzies August 1982 A #12;#12;. Stanford

  9. Integration of pneumatic fracturing and in situ vitrification in the soil subsurface

    SciTech Connect (OSTI)

    Luey, J.; Seiler, D.K. [Pacific Northwest Lab., Richland, WA (United States); Schuring, J.R.

    1995-02-01T23:59:59.000Z

    Pacific Northwest Laboratory is evaluating ways to increase the applicability of the in situ vitrification (ISV) process at hazardous and radioactive waste sites. One innovation is the placement of a conductive material that will facilitate initiating the ISV process at a target depth. A series of laboratory tests performed at the New Jersey Institute of Technology (NJIT) assessed the feasibility of pneumatic fracturing (PF) in the highly permeable soils of the Hanford Site. The NJIT tests included an analysis of Hanford soils, a series of PF injection tests, and a parametric analysis to determine how soil properties affect the PF process. Results suggest that the PF process can be applied to Hanford soils and that dry medium (e.g., conductive material such as graphite flake) can be injected into the fracture. This paper describes the laboratory testing performed at NJIT, its results, and the application of those results to plans for a field demonstration at Hanford.

  10. Tritium Transport at the Rulison Site, a Nuclear-stimulated Low-permeability Natural Gas Reservoir

    SciTech Connect (OSTI)

    C. Cooper; M. Ye; J. Chapman

    2008-04-01T23:59:59.000Z

    The U.S. Department of Energy (DOE) and its predecessor agencies conducted a program in the 1960s and 1970s that evaluated technology for the nuclear stimulation of low-permeability natural gas reservoirs. The second project in the program, Project Rulison, was located in west-central Colorado. A 40-kiltoton nuclear device was detonated 2,568 m below the land surface in the Williams Fork Formation on September 10, 1969. The natural gas reservoirs in the Williams Fork Formation occur in low permeability, fractured sandstone lenses interbedded with shale. Radionuclides derived from residual fuel products, nuclear reactions, and activation products were generated as a result of the detonation. Most of the radionuclides are contained in a cooled, solidified melt glass phase created from vaporized and melted rock that re-condensed after the test. Of the mobile gas-phase radionuclides released, tritium ({sup 3}H or T) migration is of most concern. The other gas-phase radionuclides ({sup 85}Kr, {sup 14}C) were largely removed during production testing in 1969 and 1970 and are no longer present in appreciable amounts. Substantial tritium remained because it is part of the water molecule, which is present in both the gas and liquid (aqueous) phases. The objectives of this work are to calculate the nature and extent of tritium contamination in the subsurface from the Rulison test from the time of the test to present day (2007), and to evaluate tritium migration under natural-gas production conditions to a hypothetical gas production well in the most vulnerable location outside the DOE drilling restriction. The natural-gas production scenario involves a hypothetical production well located 258 m horizontally away from the detonation point, outside the edge of the current drilling exclusion area. The production interval in the hypothetical well is at the same elevation as the nuclear chimney created by the detonation, in order to evaluate the location most vulnerable to tritium migration.

  11. Fracture characterization and estimation of fracture porosity of naturally fractured reservoirs with no matrix porosity using stochastic fractal models

    E-Print Network [OSTI]

    Kim, Tae Hyung

    2009-05-15T23:59:59.000Z

    Determining fracture characteristics at the laboratory scale is a major challenge. It is known that fracture characteristics are scale dependent; as such, the minimum sample size should be deduced in order to scale to reservoir dimensions. The main...

  12. Development of RWHet to Simulate Contaminant Transport in Fractured Porous Media

    SciTech Connect (OSTI)

    Zhang, Yong; LaBolle, Eric; Reeves, Donald M; Russell, Charles

    2012-07-01T23:59:59.000Z

    Accurate simulation of matrix diffusion in regional-scale dual-porosity and dual-permeability media is a critical issue for the DOE Underground Test Area (UGTA) program, given the prevalence of fractured geologic media on the Nevada National Security Site (NNSS). Contaminant transport through regional-scale fractured media is typically quantified by particle-tracking based Lagrangian solvers through the inclusion of dual-domain mass transfer algorithms that probabilistically determine particle transfer between fractures and unfractured matrix blocks. UGTA applications include a wide variety of fracture aperture and spacing, effective diffusion coefficients ranging four orders of magnitude, and extreme end member retardation values. This report incorporates the current dual-domain mass transfer algorithms into the well-known particle tracking code RWHet [LaBolle, 2006], and then tests and evaluates the updated code. We also develop and test a direct numerical simulation (DNS) approach to replace the classical transfer probability method in characterizing particle dynamics across the fracture/matrix interface. The final goal of this work is to implement the algorithm identified as most efficient and effective into RWHet, so that an accurate and computationally efficient software suite can be built for dual-porosity/dual-permeability applications. RWHet is a mature Lagrangian transport simulator with a substantial user-base that has undergone significant development and model validation. In this report, we also substantially tested the capability of RWHet in simulating passive and reactive tracer transport through regional-scale, heterogeneous media. Four dual-domain mass transfer methodologies were considered in this work. We first developed the empirical transfer probability approach proposed by Liu et al. [2000], and coded it into RWHet. The particle transfer probability from one continuum to the other is proportional to the ratio of the mass entering the other continuum to the mass in the current continuum. Numerical examples show that this method is limited to certain ranges of parameters, due to an intrinsic assumption of an equilibrium concentration profile in the matrix blocks in building the transfer probability. Subsequently, this method fails in describing mass transfer for parameter combinations that violate this assumption, including small diffusion coefficients (i.e., the free-water molecular diffusion coefficient 1×10-11 meter2/second), relatively large fracture spacings (such as meter), and/or relatively large matrix retardation coefficients (i.e., ). These “outliers” in parameter range are common in UGTA applications. To address the above limitations, we then developed a Direct Numerical Simulation (DNS)-Reflective method. The novel DNS-Reflective method can directly track the particle dynamics across the fracture/matrix interface using a random walk, without any empirical assumptions. This advantage should make the DNS-Reflective method feasible for a wide range of parameters. Numerical tests of the DNS-Reflective, however, show that the method is computationally very demanding, since the time step must be very small to resolve particle transfer between fractures and matrix blocks. To improve the computational efficiency of the DNS approach, we then adopted Roubinet et al.’s method [2009], which uses first passage time distributions to simulate dual-domain mass transfer. The DNS-Roubinet method was found to be computationally more efficient than the DNS-Reflective method. It matches the analytical solution for the whole range of major parameters (including diffusion coefficient and fracture aperture values that are considered “outliers” for Liu et al.’s transfer probability method [2000]) for a single fracture system. The DNS-Roubinet method, however, has its own disadvantage: for a parallel fracture system, the truncation of the first passage time distribution creates apparent errors when the fracture spacing is small, and thus it tends to erroneously predict breakthrough curves (BTCs) for th

  13. Modeling Wettability Alteration using Chemical EOR Processes in Naturally Fractured Reservoirs

    SciTech Connect (OSTI)

    Mojdeh Delshad; Gary A. Pope; Kamy Sepehrnoori

    2007-09-30T23:59:59.000Z

    The objective of our search is to develop a mechanistic simulation tool by adapting UTCHEM to model the wettability alteration in both conventional and naturally fractured reservoirs. This will be a unique simulator that can model surfactant floods in naturally fractured reservoir with coupling of wettability effects on relative permeabilities, capillary pressure, and capillary desaturation curves. The capability of wettability alteration will help us and others to better understand and predict the oil recovery mechanisms as a function of wettability in naturally fractured reservoirs. The lack of a reliable simulator for wettability alteration means that either the concept that has already been proven to be effective in the laboratory scale may never be applied commercially to increase oil production or the process must be tested in the field by trial and error and at large expense in time and money. The objective of Task 1 is to perform a literature survey to compile published data on relative permeability, capillary pressure, dispersion, interfacial tension, and capillary desaturation curve as a function of wettability to aid in the development of petrophysical property models as a function of wettability. The new models and correlations will be tested against published data. The models will then be implemented in the compositional chemical flooding reservoir simulator, UTCHEM. The objective of Task 2 is to understand the mechanisms and develop a correlation for the degree of wettability alteration based on published data. The objective of Task 3 is to validate the models and implementation against published data and to perform 3-D field-scale simulations to evaluate the impact of uncertainties in the fracture and matrix properties on surfactant alkaline and hot water floods.

  14. Three Models for Water ooding in a Naturally Fractured Petroleum ...

    E-Print Network [OSTI]

    THREE MODELS FOR WATERFLOODING IN A NATURALLY. FRACTURED ... 1. Introduction. For the purposes of this paper a naturally fractured reservoir.

  15. CT measurements of two-phase flow in fractured porous media

    SciTech Connect (OSTI)

    Hughes, R.G.; Brigham, W.E.; Castanier, L.M.

    1997-06-01T23:59:59.000Z

    The simulation of flow in naturally fractured reservoirs commonly divides the reservoir into two continua - the matrix system and the fracture system. Flow equations are written presuming that the primary flow between grid blocks occurs through the fracture system and that the primary fluid storage is in the matrix system. The dual porosity formulation of the equations assumes that there is no flow between matrix blocks while the dual permeability formulation allows fluid movement between matrix blocks. Since most of the fluid storage is contained in the matrix, recovery is dominated by the transfer of fluid from the matrix to the high conductivity fractures. The physical mechanisms influencing this transfer have been evaluated primarily through numerical studies. Relatively few experimental studies have investigated the transfer mechanisms. Early studies focused on the prediction of reservoir recoveries from the results of scaled experiments on single reservoir blocks. Recent experiments have investigated some of the mechanisms that are dominant in gravity drainage situations and in small block imbibition displacements. The mechanisms active in multiphase flow in fractured media need to be further illuminated, since some of the experimental results appear to be contradictory. This report describes the design, construction, and preliminary results of an experiment that studies imbibition displacement in two fracture blocks. Multiphase (oil/water) displacements will be conducted at the same rate on three core configurations. The configurations are a compact core, a two-block system with a 1 mm spacer between the blocks, and a two-block system with no spacer. The blocks are sealed in epoxy so that saturation measurements can be made throughout the displacement experiments using a Computed Tomography (CT) scanner.

  16. Acoustic Character Of Hydraulic Fractures In Granite

    E-Print Network [OSTI]

    Paillet, Frederick I.

    1983-01-01T23:59:59.000Z

    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 ...

  17. Fluid Flow Simulation in Fractured Reservoirs

    E-Print Network [OSTI]

    Sarkar, Sudipta

    2002-01-01T23:59:59.000Z

    The purpose of this study is to analyze fluid flow in fractured reservoirs. In most petroleum reservoirs, particularly carbonate reservoirs and some tight sands, natural fractures play a critical role in controlling fluid ...

  18. Self-potential observations during hydraulic fracturing

    E-Print Network [OSTI]

    Moore, Jeffrey R.; Glaser, Steven D.

    2008-01-01T23:59:59.000Z

    during hydraulic fracturing Moore and Glaser, in press JGR,press JGR, B – 2006JB004373 where m is the average hydraulichydraulic fracturing with water. Moore and Glaser, in press

  19. Surrogate-based optimization of hydraulic fracturing in pre-existing fracture networks

    E-Print Network [OSTI]

    Lu, Zhiming

    Surrogate-based optimization of hydraulic fracturing in pre-existing fracture networks Mingjie Chen Keywords: Hydraulic fracturing Fractal dimension Surrogate model Optimization Global sensitivity a b s t r a c t Hydraulic fracturing has been used widely to stimulate production of oil, natural gas

  20. MAGNETIC FIELD STRUCTURE IN A HIGH-MASS OUTFLOW/DISK SYSTEM

    SciTech Connect (OSTI)

    Beuther, H. [Max-Planck-Institute for Astronomy, Koenigstuhl 17, 69117 Heidelberg (Germany); Vlemmings, W. H. T. [Argelander Institute for Astronomy, University of Bonn, Auf dem Huegel 71, 53121 Bonn (Germany); Rao, R. [Academia Sinica, Institute of Astronomy and Astrophysics, Taipei, Taiwan (China); Van der Tak, F. F. S., E-mail: beuther@mpia.d, E-mail: wouter@astro.uni-bonn.d, E-mail: rrao@sma.hawaii.ed, E-mail: vdtak@sron.n [SRON Netherlands Institute for Space Research, Landleven 12, 9747 AD Groningen (Netherlands)

    2010-11-20T23:59:59.000Z

    To characterize the magnetic field structure of the outflow and core region within a prototypical high-mass star-forming region, we analyzed polarized CO(3-2)-for the first time observed with the Submillimeter Array-as well as 880 {mu}m submillimeter continuum emission from the high-mass outflow/disk system IRAS 18089-1732. Both emission features with polarization degrees at a few percent level indicate that the magnetic field structure is largely aligned with the outflow/jet orientation from small core scales to larger outflow scales. Although quantitative estimates are crude, the analysis indicates that turbulent energy dominates over magnetic energy. The data also suggest a magnetic field strength increase from the lower-density envelope to the higher-density core.

  1. agn accretion-disk outflows: Topics by E-print Network

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

    initial dipole, the field direction in the stellar wind is opposite to that in the disk wind. The maximum speed of the outflow is about the Keplerian speed at the inner disk...

  2. accretion-disk outflows ii: Topics by E-print Network

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

    field direction in the stellar wind is opposite to that in the disk wind. The maximum speed of the outflow is about the Keplerian speed at the inner disk radius. With the chosen...

  3. The role of impeller outflow conditions on the performance and stability of airfoil vaned radial diffusers

    E-Print Network [OSTI]

    Everitt, Jonathan (Jonathan Neil)

    2014-01-01T23:59:59.000Z

    This thesis quantifies the relative importance of the impeller outflow angle, Mach number, non-uniformity and unsteadiness on diffuser performance, through diffuser experiments in a compressor stage and in a swirling flow ...

  4. Wave Propagation in Fractured Poroelastic Media

    E-Print Network [OSTI]

    Seismic wave propagation through fractures and cracks is an important subject in exploration and production geophysics, earthquake seismology and mining.

  5. A Simple Model for Estimating Water Balance and Salinity of Reservoirs and Outflow

    E-Print Network [OSTI]

    Miyamoto, S; Yuan, F; Anand, Shilpa

    2010-08-23T23:59:59.000Z

    on flow and salinity of the stream and the floodplains. The first part deals with water and salt balance in reservoirs. The primary purpose of the model is to predict outflow salinity from the reservoir storage and inflow information in advance... management strategy, yet the method to predict outflow salinity has not been adequately examined. The study reported here examined the water and salt balance in a reservoir using a two-layer model. This model assumes that inflow blends with the storage...

  6. Discrete fracture modeling for fractured reservoirs using Voronoi grid blocks

    E-Print Network [OSTI]

    Gross, Matthew Edward

    2007-09-17T23:59:59.000Z

    or pseudofracture groups modeled in their own grid blocks. Discrete Fracture Modeling (DFN) is still a relatively new field, and most research on it up to this point has been done with Delaunay tessellations. This research investigates an alternative approach using...

  7. Self-potential observations during hydraulic fracturing

    E-Print Network [OSTI]

    Moore, Jeffrey R.; Glaser, Steven D.

    2008-01-01T23:59:59.000Z

    1968), Permeability of granite under high pressure, J.resistivity during creep in granite, Pure Appl. Geophys. ,properties of westerly granite with applications, J.

  8. Prompt optical emission from residual collisions in GRB outflows

    E-Print Network [OSTI]

    Zhuo Li; Eli Waxman

    2008-01-03T23:59:59.000Z

    The prompt gamma-ray emission in gamma-ray bursts is believed to be produced by internal shocks within a relativistic unsteady outflow. The recent detection of prompt optical emission accompanying the prompt gamma-ray emission appears to be inconsistent with this model since the out flowing plasma is expected to be highly optically thick to optical photons. We show here that fluctuations in flow properties on short, ~ 1 ms, time scale, which drive the gamma-ray producing collisions at small radii, are expected to lead to "residual" collisions at much larger radii, where the optical depth to optical photons is low. The late residual collisions naturally account for the relatively bright optical emission. The apparent simultaneity of gamma-ray and optical emission is due to the highly relativistic speed with which the plasma expands. Residual collisions may also account for the X-ray emission during the early "steep decline" phase, where the radius is inferred to be larger than the gamma-ray emission radius. Finally, we point out that inverse-Compton emission from residual collisions at large radii is expected to contribute significantly to the emission at high energy, and may therefore "smear" the pair production spectral cut-off.

  9. Pulse Structure of Hot Electromagnetic Outflows with Embedded Baryons

    E-Print Network [OSTI]

    Thompson, Christopher

    2014-01-01T23:59:59.000Z

    Gamma-ray bursts (GRBs) show a dramatic pulse structure that requires bulk relativistic motion, but whose physical origin has remained murky. We focus on a hot, magnetized jet that is emitted by a black hole and interacts with a confining medium. Strongly relativistic expansion of the magnetic field, as limited by a corrugation instability, may commence only after it forms a thin shell. Then the observed $T_{90}$ burst duration is dominated by the curvature delay, and null periods arise from angular inhomogeneities, not the duty cycle of the engine. We associate the $O(1)$ s timescale observed in the pulse width distribution of long GRBs with the collapse of the central 2.5-3$M_\\odot$ of a massive stellar core. A fraction of the baryons are shown to be embedded in the magnetized outflow by the hyper-Eddington radiation flux; they strongly disturb the magnetic field after the compactness drops below $\\sim 4\\times 10^3(Y_e/0.5)^{-1}$. The high-energy photons so created have a compressed pulse structure. Delayed...

  10. Relativistic outflow from two thermonuclear shell flashes on neutron stars

    E-Print Network [OSTI]

    Zand, Jean in 't; Cavecchi, Yuri

    2014-01-01T23:59:59.000Z

    We study the exceptionally short (32-41 ms) precursors of two intermediate-duration thermonuclear X-ray bursts observed with RXTE from the neutron stars in 4U 0614+09 and 2S 0918-549. They exhibit photon fluxes that surpass those at the Eddington limit later in the burst by factors of 2.6 to 3.1. We are able to explain both the short duration and the super-Eddington flux by mildly relativistic outflow velocities of 0.1$c$ to 0.3$c$ subsequent to the thermonuclear shell flashes on the neutron stars. These are the highest velocities ever measured from any thermonuclear flash. The precursor rise times are also exceptionally short: about 1 ms. This is inconsistent with predictions for nuclear flames spreading laterally as deflagrations and suggests detonations instead. This is the first time that a detonation is suggested for such a shallow ignition column depth ($y_{\\rm ign}$ = 10$^{10}$ g cm$^{-2}$). The detonation would possibly require a faster nuclear reaction chain, such as bypassing the alpha-capture on $^...

  11. Hydraulic Fracture: multiscale processes and moving

    E-Print Network [OSTI]

    Peirce, Anthony

    Hydraulic Fracture: multiscale processes and moving interfaces Anthony Peirce Department Mitchell (UBC) · Ed Siebrits (SLB, Houston) #12;2 Outline · What is a hydraulic fracture? · Scaling Fluid Proppant #12;6 An actual hydraulic fracture #12;7 HF experiment (Jeffrey et al CSIRO) #12;8 1D

  12. Hydraulic Fracture: multiscale processes and moving

    E-Print Network [OSTI]

    Peirce, Anthony

    Hydraulic Fracture: multiscale processes and moving interfaces Anthony Peirce Department Siebrits (SLB, Houston) #12;2 Outline · What is a hydraulic fracture? · Mathematical models of hydraulic fracture · Scaling and special solutions for 1-2D models · Numerical modeling for 2-3D problems

  13. RATE DECLINE ANALYSIS FOR NATURALLY FRACTURED RESERVOIRS

    E-Print Network [OSTI]

    Stanford University

    RATE DECLINE ANALYSIS FOR NATURALLY FRACTURED RESERVOIRS A REPORT SUBMITTED TO THE DEPARTMENT analylsiis for constant pressure production in a naturally fractured reservoir is presented. The solution, the Warren and Root model which assumes fracturing is perfectly unifom, provides an upper bound of reservoir

  14. Regulation of Hydraulic Fracturing in California

    E-Print Network [OSTI]

    Kammen, Daniel M.

    APRIL 2013 Regulation of Hydraulic Fracturing in California: A WAsteWAteR And WAteR QuAlity Pe | Regulation of Hydraulic Fracturing in California Wheeler Institute for Water Law & Policy Center for Law #12;Regulation of Hydraulic Fracturing in California | 3Berkeley law | wheeler InstItute for water law

  15. Fractured shale reservoirs: Towards a realistic model

    SciTech Connect (OSTI)

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

    1996-09-01T23:59:59.000Z

    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).

  16. Time-dependent and outflow boundary conditions for Dissipative Particle Dynamics

    SciTech Connect (OSTI)

    Lei Huan [Division of Applied Mathematics, Brown University, Providence, RI 02912 (United States); Fedosov, Dmitry A. [Division of Applied Mathematics, Brown University, Providence, RI 02912 (United States); Institut fuer Festkoerperforschung, Forschungszentrum Juelich, 52425 Juelich (Germany); Karniadakis, George Em, E-mail: George_Karniadakis@brown.ed [Division of Applied Mathematics, Brown University, Providence, RI 02912 (United States)

    2011-05-10T23:59:59.000Z

    We propose a simple method to impose both no-slip boundary conditions at fluid-wall interfaces and at outflow boundaries in fully developed regions for Dissipative Particle Dynamics (DPD) fluid systems. The procedure to enforce the no-slip condition is based on a velocity-dependent shear force, which is a generalized force to represent the presence of the solid-wall particles and to maintain locally thermodynamic consistency. We show that this method can be implemented in both steady and time-dependent fluid systems and compare the DPD results with the continuum limit (Navier-Stokes) results. We also develop a force-adaptive method to impose the outflow boundary conditions for fully developed flow with unspecified outflow velocity profile or pressure value. We study flows over the backward-facing step and in idealized arterial bifurcations using a combination of the two new boundary methods with different flow rates. Finally, we explore the applicability of the outflow method in time-dependent flow systems. The outflow boundary method works well for systems with Womersley number of O(1), i.e. when the pressure and flowrate at the outflow are approximately in-phase.

  17. Theory of Bipolar Outflows from High-Mass Young Stellar Objects

    E-Print Network [OSTI]

    Arieh Konigl

    1999-03-11T23:59:59.000Z

    There is a growing number of observational indicators for the presence of bipolar outflows in massive, young stellar objects that are still accreting mass as part of their formation process. In particular, there is evidence that the outflows from these objects can attain higher velocities and kinetic luminosities than their lower-mass counterparts. Furthermore, the higher-mass objects appear to smoothly continue the correlation found in T Tauri stars between outflow and accretion signatures, and in several cases there are direct clues to the existence of a circumstellar disk from optical and infrared imaging and spectroscopy as well as from millimeter-wavelength interferometry. These results suggest that the disk-outflow connection found in low-mass pre-main-sequence stars extends to more massive objects, and that a similar physical mechanism may drive the outflows in both cases. I examine the observational basis for this hypothesis and consider how the commonly invoked centrifugally driven wind models of bipolar outflows in low-mass stars would be affected by the various physical processes (such as photoionization, photoevaporation, radiation pressure, and stellar wind ram pressure) that operate in higher-mass stars. I then list some of the interesting questions that one could hope to address as this young field of research continues to develop.

  18. MAGNETIC RECONNECTION ALONG QUASI-SEPARATRIX LAYERS AS A DRIVER OF UBIQUITOUS ACTIVE REGION OUTFLOWS

    SciTech Connect (OSTI)

    Baker, D.; Van Driel-Gesztelyi, L.; Murray, M. J. [University College London, Mullard Space Science Laboratory, Holmbury St. Mary, Dorking, Surrey RH5 6NT (United Kingdom); Mandrini, C. H. [Instituto de AstronomIa y fisica del Espacio, CONICET-UBA, CC. 67, Suc. 28, 1428 Buenos Aires (Argentina); Demoulin, P. [Observatoire de Paris, LESIA, UMR 8109 (CNRS), Meudon-Principal Cedex (France)

    2009-11-01T23:59:59.000Z

    Hinode's EUV Imaging Spectrometer (EIS) has discovered ubiquitous outflows of a few to 50 km s{sup -1} from active regions (ARs). These outflows are most prominent at the AR boundary and appear over monopolar magnetic areas. They are linked to strong non-thermal line broadening and are stronger in hotter EUV lines. The outflows persist for at least several days. Using Hinode EIS and X-Ray Telescope observations of AR 10942 coupled with magnetic modeling, we demonstrate that the outflows originate from specific locations of the magnetic topology where field lines display strong gradients of magnetic connectivity, namely quasi-separatrix layers (QSLs), or in the limit of infinitely thin QSLs, separatrices. We found the strongest AR outflows to be in the vicinity of QSL sections located over areas of strong magnetic field. We argue that magnetic reconnection at QSLs separating closed field lines of the AR and either large-scale externally connected or 'open' field lines is a viable mechanism for driving AR outflows which are likely sources of the slow solar wind.

  19. Hydromechanical modeling of pulse tests that measure both fluidpressure and fracture-normal displacement of the Coaraze Laboratory site,France

    SciTech Connect (OSTI)

    Cappa, F.; Guglielmi, Y.; Rutqvist, J.; Tsang, C-F.; Thoraval, A.

    2006-04-22T23:59:59.000Z

    In situ fracture mechanical deformation and fluid flowinteractions are investigated through a series of hydraulic pulseinjection tests, using specialized borehole equipment that cansimultaneously measure fluid pressure and fracture displacements. Thetests were conducted in two horizontal boreholes spaced one meter apartvertically and intersecting a near-vertical highly permeable faultlocated within a shallow fractured carbonate rock. The field data wereevaluated by conducting a series of coupled hydromechanical numericalanalyses, using both distinct-element and finite-element modelingtechniques and both two- and three-dimensional model representations thatcan incorporate various complexities in fracture network geometry. Oneunique feature of these pulse injection experiments is that the entiretest cycle, both the initial pressure increase and subsequent pressurefall-off, is carefully monitored and used for the evaluation of the insitu hydromechanical behavior. Field test data are evaluated by plottingfracture normal displacement as a function of fluid pressure, measured atthe same borehole. The resulting normal displacement-versus-pressurecurves show a characteristic loop, in which the paths for loading(pressure increase) and unloading (pressure decrease) are different. Bymatching this characteristic loop behavior, the fracture normal stiffnessand an equivalent stiffness (Young's modulus) of the surrounding rockmass can be back-calculated. Evaluation of the field tests by couplednumerical hydromechanical modeling shows that initial fracture hydraulicaperture and normal stiffness vary by a factor of 2 to 3 for the twomonitoring points within the same fracture plane. Moreover, the analysesshow that hydraulic aperture and the normal stiffness of the pulse-testedfracture, the stiffness of surrounding rock matrix, and the propertiesand geometry of the surrounding fracture network significantly affectcoupled hydromechanical responses during the pulse injection test. Morespecifically, the pressure-increase path of the normaldisplacement-versus-pressure curve is highly dependent on thehydromechanical parameters of the tested fracture and the stiffness ofthe matrix near the injection point, whereas the pressure-decrease pathis highly influenced by mechanical processes within a larger portion ofthe surrounding fractured rock.

  20. Preliminary relative permeability estimates of methanehydrate-bearing sand

    SciTech Connect (OSTI)

    Seol, Yongkoo; Kneafsey, Timothy J.; Tomutsa, Liviu; Moridis,George J.

    2006-05-08T23:59:59.000Z

    The relative permeability to fluids in hydrate-bearingsediments is an important parameter for predicting natural gas productionfrom gas hydrate reservoirs. We estimated the relative permeabilityparameters (van Genuchten alpha and m) in a hydrate-bearing sand by meansof inverse modeling, which involved matching water saturation predictionswith observations from a controlled waterflood experiment. We used x-raycomputed tomography (CT) scanning to determine both the porosity and thehydrate and aqueous phase saturation distributions in the samples. X-rayCT images showed that hydrate and aqueous phase saturations arenon-uniform, and that water flow focuses in regions of lower hydratesaturation. The relative permeability parameters were estimated at twolocations in each sample. Differences between the estimated parametersets at the two locations were attributed to heterogeneity in the hydratesaturation. Better estimates of the relative permeability parametersrequire further refinement of the experimental design, and betterdescription of heterogeneity in the numerical inversions.

  1. Geomechanical Simulation of Fluid-Driven Fractures

    SciTech Connect (OSTI)

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

    2012-11-30T23:59:59.000Z

    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.

  2. Effects of Water Injection into Fractured Geothermal Reservoirs: A Summary of Experience Worldwide

    SciTech Connect (OSTI)

    Horne, Roland N.

    1982-06-01T23:59:59.000Z

    Reinjection of water into fractured geothermal reservoirs holds potential both for improvement and degradation of total energy recovery. The replacement of reservoir fluid can mean support of placement of reservoir pressures and also more efficient thermal energy recovery, but at the same time the premature invasion of reinjected water back into production wells through high permeability fractures can reduce discharge enthalpy and hence deliverability and useful energy output. Increases in reservoir pressure and maintenance of field output have been observed in operating fields, but unfortunately so too have premature thermal breakthroughs. The design of reinjection schemes, therefore, requires careful investigation into the likely effects, using field experimentation. This paper summarizes field experience with reinjection around the world, with the intention of elucidating characteristics of possible problems. The results summarized in this paper fall into three categories of interest: permeability changes dye to injection (both increases and decreases); the path followed by injected water (as indicated by tracer tests); and the thermal and hydraulic influences of injection on the reinjection well itself and on surrounding producers. [DJE-2005

  3. RESEARCH PROGRAM ON FRACTURED PETROLEUM RESERVOIRS

    SciTech Connect (OSTI)

    Abbas Firoozabadi

    2002-04-12T23:59:59.000Z

    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.

  4. Upscaling verticle permeability within a fluvio-aeolian reservoir

    SciTech Connect (OSTI)

    Thomas, S.D.; Corbett, P.W.M.; Jensen, J.L. [Heriot-Watt Univ., Edinburgh (United Kingdom)

    1997-08-01T23:59:59.000Z

    Vertical permeability (k{sub v}) is a crucial factor in many reservoir engineering issues. To date there has been little work undertaken to understand the wide variation of k{sub v} values measured at different scales in the reservoir. This paper presents the results of a study in which we have modelled the results of a downhole well tester using a statistical model and high resolution permeability data. The work has demonstrates and quantifies a wide variation in k{sub v} at smaller, near wellbore scales and has implications for k{sub v} modelling at larger scales.

  5. Importance of Low Permeability Natural Gas Reservoirs (released in AEO2010)

    Reports and Publications (EIA)

    2010-01-01T23:59:59.000Z

    Production from low-permeability reservoirs, including shale gas and tight gas, has become a major source of domestic natural gas supply. In 2008, low-permeability reservoirs accounted for about 40% of natural gas production and about 35% of natural gas consumption in the United States. Permeability is a measure of the rate at which liquids and gases can move through rock. Low-permeability natural gas reservoirs encompass the shale, sandstone, and carbonate formations whose natural permeability is roughly 0.1 millidarcies or below. (Permeability is measured in darcies.)

  6. SiO Outflow Signatures Toward Massive Young Stellar Objects with Linearly Distributed Methanol Masers

    E-Print Network [OSTI]

    J. M. De Buizer; R. O. Redman; S. N. Longmore; J. Caswell; P. A. Feldman

    2008-10-27T23:59:59.000Z

    Methanol masers are often found in linear distributions, and it has been hypothesized that these masers are tracing circumstellar accretion disks around young massive stars. However, recent observations in H2 emission have shown what appear to be outflows at similar angles to the maser distribution angles, not perpendicular as expected in the maser-disk scenario. The main motivation behind the observations presented here is to determine from the presence and morphology of an independent outflow tracer, namely SiO, if there are indeed outflows present in these regions and if they are consistent or inconsistent with the maser-disk hypothesis. For ten sources with H2 emission we obtained JCMT single dish SiO (6-5) observations to search for the presence of this outflow indicator. We followed up those observations with ATCA interferometric mapping of the SiO emission in the (2-1) line in six sources. The JCMT observations yielded a detection in the SiO (6-5) line in nine of the ten sources. All of the sources with bright SiO lines display broad line wings indicative of outflow. A subset of the sources observed with the JCMT have methanol maser velocities significantly offset from their parent cloud velocities, supporting the idea that the masers in these sources are likely not associated with circumstellar disks. The ATCA maps of the SiO emission show five of the six sources do indeed have SiO outflows. The spatial orientations of the outflows are not consistent with the methanol masers delineating disk orientations. Overall, the observations presented here seem to provide further evidence against the hypothesis that linearly distributed methanol masers generally trace the orientations of circumstellar disks around massive young stars.

  7. Acid Fracture and Fracture Conductivity Study of Field Rock Samples

    E-Print Network [OSTI]

    Underwood, Jarrod

    2013-11-15T23:59:59.000Z

    (Black and Hower 1965). Clays consist of negatively charged aluminosilicate layers kept together by cations. The most characteristic property is their ability to adsorb water between the layers, resulting in strong repulsive forces and clay expansion... chemicals used in water fracturing such as friction reducers, fluid-loss additives, and surfactants (Black and Hower 1965). The samples used in this study had significant clay-like content. To prevent swelling, a 2% KCl solution was used throughout...

  8. A SYSTEMATIC SEARCH FOR MOLECULAR OUTFLOWS TOWARD CANDIDATE LOW-LUMINOSITY PROTOSTARS AND VERY LOW LUMINOSITY OBJECTS

    SciTech Connect (OSTI)

    Schwarz, Kamber R.; Shirley, Yancy L. [Steward Observatory, 933 N. Cherry Ave., Tucson, AZ 85721 (United States); Dunham, Michael M. [Department of Astronomy, Yale University, P.O. Box 208101, New Haven, CT 06520 (United States)

    2012-10-01T23:59:59.000Z

    We present a systematic single-dish search for molecular outflows toward a sample of nine candidate low-luminosity protostars and 30 candidate very low luminosity objects (VeLLOs; L{sub int} {<=} 0.1 L{sub Sun }). The sources are identified using data from the Spitzer Space Telescope cataloged by Dunham et al. toward nearby (D < 400 pc) star-forming regions. Each object was observed in {sup 12}CO and {sup 13}CO J = 2 {yields} 1 simultaneously using the sideband separating ALMA Band-6 prototype receiver on the Heinrich Hertz Telescope at 30'' resolution. Using five-point grid maps, we identify five new potential outflow candidates and make on-the-fly maps of the regions surrounding sources in the dense cores B59, L1148, L1228, and L1165. Of these new outflow candidates, only the map of B59 shows a candidate blue outflow lobe associated with a source in our survey. We also present larger and more sensitive maps of the previously detected L673-7 and the L1251-A-IRS4 outflows and analyze their properties in comparison to other outflows from VeLLOs. The accretion luminosities derived from the outflow properties of the VeLLOs with detected CO outflows are higher than the observed internal luminosity of the protostars, indicating that these sources likely had higher accretion rates in the past. The known L1251-A-IRS3 outflow is detected but not re-mapped. We do not detect clear, unconfused signatures of red and blue molecular wings toward the other 31 sources in the survey indicating that large-scale, distinct outflows are rare toward this sample of candidate protostars. Several potential outflows are confused with the kinematic structure in the surrounding core and cloud. Interferometric imaging is needed to disentangle large-scale molecular cloud kinematics from these potentially weak protostellar outflows.

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

    E-Print Network [OSTI]

    Nelson, J.T.

    2009-01-01T23:59:59.000Z

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

  10. VisualizationandHierarchicalAnalysisofFlowinDiscreteFractureNetworkModels Flow and transport in low permeability fractured rock is primary in interconnected fracture networks. Prediction and characterization of ow and transport in fractured rock has impor

    E-Print Network [OSTI]

    Hamann, Bernd

    . A steady-state ow solution for saturated water is obtained using FEHM (Finite Element Heat and Mass resource management, and hydrocarbon extraction. We have developed methods to explicitly model ow ective use of traditional visualization methods. We would also like quantitative analysis methods

  11. Remediation of a fractured clay soil contaminated with gasoline containing MTBE

    SciTech Connect (OSTI)

    Johnson, R.L.; Grady, D.E. [Oregon Graduate Institute, Portland, OR (United States); Walden, T. [BP Oil Europe, Brussels (Belgium)

    1997-12-31T23:59:59.000Z

    Gasoline and other light non-aqueous phase liquids (LNAPLs) released into fractured clay soils initially move by advection of the LNAPL through the fractures. Once advective movement of the LNAPL ceases, dissolution of the gasoline components into the pore water and diffusion into the intact blocks of clay becomes an important transport process. The aqueous-phase flux of each compound in the mixture depends in large part upon its aqueous solubility. For example, a low-solubility compound like isooctane remains primarily in the fracture in the LNAPL. A high-solubility compound, like methyl-tert-butyl ether (MTBE), dissolves readily and may move almost entirely into the clay matrix. The distribution of compounds between the matrix and the fractures will have an important impact on the rate at which the gasoline contaminated soil can be remediated. In this context, the presence of soluble additives like MTBE can significantly impact the risk and remediation time for the, soil. Beginning in 1993 a field study to examine the applicability of air flushing for remediation of low-permeability soils was sponsored by API. The study focused on a variety of soil vapor extraction (SVE) and in situ air sparging (IAS) approaches for mass removal and risk reduction. The source of gasoline contamination in this study was a release of 50 liters of a mixture containing 14 gasoline hydrocarbons ranging from pentane to naphthalene, and including MTBE. The mixture was released into the shallow subsurface and allowed to redistribute for 10 months prior to air flushing startup. Numerical modeling indicated that essentially all of the MTBE should have dissolved into the matrix. In contrast, essentially all of the isooctane should have remained in the LNAPL in the fractures.

  12. Characterizing Curing-Cement Slurries by Permeability, Tensile Strength,

    E-Print Network [OSTI]

    Backe, Knut

    Characterizing Curing-Cement Slurries by Permeability, Tensile Strength, and Shrinkage K.R. Backe oilwell cements. The results show that the curing characteristics are a function of temperature and that there is a correlation between shrinkage and cement content. The paper also introduces a new mechanism for gas migration

  13. MULTILEVEL FAST MULTIPOLE METHOD FOR MODELING PERMEABLE STRUCTURES

    E-Print Network [OSTI]

    Sarabandi, Kamal

    MULTILEVEL FAST MULTIPOLE METHOD FOR MODELING PERMEABLE STRUCTURES USING CONFORMAL FINITE ELEMENTS #12;Copyright c Kubilay Sertel All Rights Reserved 2003 #12;ABSTRACT MULTILEVEL FAST MULTIPOLE METHOD fast multipole method for impen- etrable targets in the context of flat-triangular geometry

  14. Permeable Interlocking Concrete Pavement (PICP) for Stormwater Management

    E-Print Network [OSTI]

    Permeable Interlocking Concrete Pavement (PICP) for Stormwater Management Benefits and Uses · Potential for Extended Pavement Life Due to Well Drained Base and Reduced Freeze-Thaw · No curing time Cost Can Be Comparable for PICP with Reduced Stormwater Infrastructure VS. Standard Pavement

  15. An asymptotic model of seismic reflection from a permeable layer

    SciTech Connect (OSTI)

    Silin, D.; Goloshubin, G.

    2009-10-15T23:59:59.000Z

    Analysis of compression wave propagation in a poroelastic medium predicts a peak of reflection from a high-permeability layer in the low-frequency end of the spectrum. An explicit formula expresses the resonant frequency through the elastic moduli of the solid skeleton, the permeability of the reservoir rock, the fluid viscosity and compressibility, and the reservoir thickness. This result is obtained through a low-frequency asymptotic analysis of Biot's model of poroelasticity. A review of the derivation of the main equations from the Hooke's law, momentum and mass balance equations, and Darcy's law suggests an alternative new physical interpretation of some coefficients of the classical poroelasticity. The velocity of wave propagation, the attenuation factor, and the wave number, are expressed in the form of power series with respect to a small dimensionless parameter. The absolute value of this parameter is equal to the product of the kinematic reservoir fluid mobility and the wave frequency. Retaining only the leading terms of the series leads to explicit and relatively simple expressions for the reflection and transmission coefficients for a planar wave crossing an interface between two permeable media, as well as wave reflection from a thin highly-permeable layer (a lens). Practical applications of the obtained asymptotic formulae are seismic modeling, inversion, and at-tribute analysis.

  16. OUTFLOWS FROM EVOLVED STARS: THE RAPIDLY CHANGING FINGERS OF CRL 618

    SciTech Connect (OSTI)

    Balick, Bruce [Department of Astronomy, University of Washington, Seattle, WA 98195-1580 (United States); Huarte-Espinosa, Martin [Department of Physics and Astronomy, University of Rochester, Rochester, NY 14627 (United States); Frank, Adam; Gomez, Thomas [Astronomy Department, University of Texas, Austin, TX 78731-2330 (United States); Alcolea, Javier [Observatorio Astronomico Nacional (IGN), E-28014 Madrid (Spain); Corradi, Romano L. M. [Instituto de Astrofisica de Canarias, E-38200 La Laguna, Tenerife (Spain); Vinkovic, Dejan, E-mail: balick@uw.edu, E-mail: martinHE@pas.rochester.edu, E-mail: afrank@pas.rochester.edu, E-mail: gomezt@astro.as.utexas.edu, E-mail: j.alcolea@oan.es, E-mail: rcorradi@iac.es, E-mail: vinkovic@pmfst.hr [Physics Department, University of Split, Teslina 12/III, HR-21000 Split (Croatia)

    2013-07-20T23:59:59.000Z

    Our ultimate goal is to probe the nature of the collimator of the outflows in the pre-planetary nebula CRL 618. CRL 618 is uniquely suited for this purpose owing to its multiple, bright, and carefully studied finger-shaped outflows east and west of its nucleus. We compare new Hubble Space Telescope images to images in the same filters observed as much as 11 yr ago to uncover large proper motions and surface brightness changes in its multiple finger-shaped outflows. The expansion age of the ensemble of fingers is close to 100 yr. We find strong brightness variations at the fingertips during the past decade. Deep IR images reveal a multiple ring-like structure of the surrounding medium into which the outflows propagate and interact. Tightly constrained three-dimensional hydrodynamic models link the properties of the fingers to their possible formation histories. We incorporate previously published complementary information to discern whether each of the fingers of CRL 618 are the results of steady, collimated outflows or a brief ejection event that launched a set of bullets about a century ago. Finally, we argue on various physical grounds that fingers of CRL 618 are likely to be the result of a spray of clumps ejected at the nucleus of CRL 618 since any mechanism that form a sustained set of unaligned jets is unprecedented.

  17. 6.7GHz Methanol Maser Associated Outflows: An evolutionary sequence

    E-Print Network [OSTI]

    de Villiers, H M; Thompson, M A; Urquhart, J S; Breen, S L; Burton, M G; Ellingsen, S P; Fuller, G A; Pestalozzi, M; Voronkov, M A; Ward-Thompson, D

    2015-01-01T23:59:59.000Z

    We present a continuing study of a sample 44 molecular outflows, observed in 13CO lines, closely associated with 6.7GHz methanol masers, hence called Methanol Maser Associated Outflows (MMAOs). We compare MMAO properties with those of outflows from other surveys in the literature. In general, MMAOs follow similar trends, but show a deficit in number at low masses and momenta, with a corresponding higher fraction at the high end of the distributions. A similar trend is seen for the dynamical timescales of MMAOs. We argue that the lack of relatively low mass and young flows in MMAOs is due to the inherent selection-bias in the sample, i.e. its direct association with 6.7GHz methanol masers. This implies that methanol masers must switch on after the onset of outflows (hence accretion), and not before a sufficient abundance of methanol is liberated from icy dust mantles. Consequently the average dynamical age of MMAOs is older than for the general population of molecular outflows. We propose an adjusted evolution...

  18. AGN feedback: galactic-scale outflows driven by radiation pressure on dust

    E-Print Network [OSTI]

    Ishibashi, W

    2015-01-01T23:59:59.000Z

    Galaxy-scale outflows, which are thought to provide the link connecting the central black hole to its host galaxy, are now starting to be observed. However, the physical origin of the mechanism driving the observed outflows, whether due to energy-driving or radiation-driving, is still debated; and in some cases, it is not clear whether the central source is an active galactic nucleus (AGN) or a nuclear starburst. Here we study the role of radiation pressure on dust in driving galactic-scale AGN outflows, and analyse the dynamics of the outflowing shell as a function of the underlying physical parameters. We show that high-velocity outflows ($\\gtrsim$1000 km/s) with large momentum flux ($\\gtrsim 10 L/c$) can be obtained, by taking into account the effects of radiation trapping. In particular, the high observed values of the momentum boosts can be reproduced, provided that the shell is initially optically thick to the reprocessed infrared radiation. Alternatively, the inferred measurements of the momentum flux ...

  19. Multi-wavelength spectroscopy of the bipolar outflow from Cepheus E

    E-Print Network [OSTI]

    M. D. Smith; D. Froebrich; J. Eislöffel

    2003-04-03T23:59:59.000Z

    Cepheus E is the site of an exceptional example of a protostellar outflow with a very young dynamical age and extremely high near infrared luminosity. We combine molecular spectroscopic data from the submillimeter to the near infrared in order to interpret the rotational excitation of CO and the ro-vibrational excitation of H2. We conclude that C-type shocks with a paraboloidal bow shock geometry can simultaneously explain all the molecular excitations. Extinction accounts for the deviation of the column densities from local thermodynamic equilibrium. A difference in the extinction between the red and blue-shifted outflow lobes may account for the measured flux difference. The outflow is deeply embedded in a clump of density 10^5cm^-3, yet a good fraction of atomic hydrogen, about 40%, is required to explain the excitation and statistical equilibrium. We propose that this atomic component arises, self-consistently, from the dissociated gas at the apex of the leading bow shocks and the relatively long molecule reformation time. At least 20 bow shocks are required in each lobe, although these may be sub-divided into smaller bows and turbulent shocked regions. The total outflow mechanical power and cooling amounts to over 30L_\\odot, almost half the source's bolometric luminosity. Nevertheless, only about 6% of the clump mass has been set in outward motion by the outflow, allowing a collapse to continue.

  20. LARGE SCALE PERMEABILITY TEST OF THE GRANITE IN THE STRIPA MINE AND THERMAL CONDUCTIVITY TEST

    E-Print Network [OSTI]

    Lundstrom, L.

    2011-01-01T23:59:59.000Z

    PERMEABILITY TEST OF THE GRANITE' IN THE STRIPA MINE AND,PERMEABILITY TEST OF THE GRANITE IN THE STRIPA MINE ANDPERMEABILITY TEST OF THE GRANITE IN THE STRIPA MINE AND

  1. Evaluation of a permeability-porosity relationship in a low permeability creeping material using a single transient test

    E-Print Network [OSTI]

    Ghabezloo, Siavash; Saint-Marc, Jérémie; 10.1016/j.ijrmms.2008.10.003

    2008-01-01T23:59:59.000Z

    A method is presented for the evaluation of the permeability-porosity relationship in a low-permeability porous material using the results of a single transient test. This method accounts for both elastic and non-elastic deformations of the sample during the test and is applied to a hardened class G oil well cement paste. An initial hydrostatic undrained loading is applied to the sample. The generated excess pore pressure is then released at one end of the sample while monitoring the pore pressure at the other end and the radial strain in the middle of the sample during the dissipation of the pore pressure. These measurements are back analysed to evaluate the permeability and its evolution with porosity change. The effect of creep of the sample during the test on the measured pore pressure and volume change is taken into account in the analysis. This approach permits to calibrate a power law permeability-porosity relationship for the tested hardened cement paste. The porosity sensitivity exponent of the power...

  2. Apparatus and method for monitoring underground fracturing

    DOE Patents [OSTI]

    Warpinski, Norman R. (Albuquerque, NM); Steinfort, Terry D. (Tijeras, NM); Branagan, Paul T. (Las Vegas, NV); Wilmer, Roy H. (Las Vegas, NV)

    1999-08-10T23:59:59.000Z

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

  3. Apparatus and method for monitoring underground fracturing

    DOE Patents [OSTI]

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

    1999-08-10T23:59:59.000Z

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

  4. Research consortium on fractured petroleum reservoirs. Third quarterly report, July 1--September 30, 1993

    SciTech Connect (OSTI)

    Firoozabadi, A.; Markeset, T.

    1993-11-22T23:59:59.000Z

    Our 1993 third quarter report discusses the results of our work on: (1) gas-oil gravity drainage in layered media; and, (2) the influence of viscous forces on gas-oil flow in fractured porous media. For sometime, we have been working on the incorporation of reinfiltration and capillary continuity concepts in a dual-porosity model. A simple and accurate technique has been developed for this purpose. The experiments on gas-oil gravity drainage in layered media are intended to: (1) verify our theoretical analysis; (2) provide more insight; and, (3) provide a guide for the simulation of gas-oil gravity drainage at field scale. On the first objective, the experiments confirm that gas-oil gravity drainage could result in a downward gas fingering phenomenon. Without capillary pressure, downward gas fingering could not realize. The experiments also show that drainage from a less permeable layer would be an extremely slow process. This is similar to the drainage performance of matrix blocks in fractured porous media. Apparently, relative permeability to gas (i.e. gas mobility) may be important for flow in layered porous media. The project on the effect of viscous forces on gas-oil displacement in fractured porous media has taken longer than anticipated. For the first time, in gravity drainage experiments of the matrix-fracture configuration used in this project, we could not obtain reproducible results. After several tests, we teamed that the surface tension of the normal-decane/air system changes in the presence of the coating cover which was used in the experimental assembly of this project. We removed the coating. The experiments can now be reproduced. The data show that there is a strong effect of viscous forces on matrix/fracture flow. A small imposed pressure gradient results in a substantial amount of oil recovery. After performing 3-4 more tests, the data will be analyzed and an appropriate model will be developed to relate experimental data to field conditions.

  5. Permeability of illite-bearing shale: 2. Influence of fluid chemistry on flow and functionally

    E-Print Network [OSTI]

    Herbert, Bruce

    Permeability of illite-bearing shale: 2. Influence of fluid chemistry on flow and functionally; accepted 14 July 2004; published 14 October 2004. [1] Bedding-parallel permeability of illite-rich shale Geochemistry: Low-temperature geochemistry; KEYWORDS: permeability, shale, fluid chemistry Citation: Kwon, O

  6. I N F I N I T E CONDUCTIVITY FRACTURE NATURALLY FRACTURED RESERVOIR

    E-Print Network [OSTI]

    Stanford University

    I N F I N I T E CONDUCTIVITY FRACTURE I N A NATURALLY FRACTURED RESERVOIR A REPORT SUBMITTED How& #12;ABSTRACT This r e p o r t describes t h e behavior of a n a t u r a l l y fractured r e s e r v o i r when a well is producing a t constant rate through an i n f i n i t e conductivity fracture

  7. STRENGTH AND PERMEABILITY TESTS ON ULTRA-LARGE STRIPA GRANITE CORE

    E-Print Network [OSTI]

    Thorpe, R.

    2009-01-01T23:59:59.000Z

    granite • • • • • • • • • • • '. • • • • • • • • • • • • •· . . Mohr diagram for intact Stripa granite . .healed fractures in Stripa granite. · . · . . Key to figures

  8. Chemically- and mechanically-mediated influences on the transport and mechanical characteristics of rock fractures

    SciTech Connect (OSTI)

    Min, K.-B.; Rutqvist, J.; Elsworth, D.

    2009-02-01T23:59:59.000Z

    A model is presented to represent changes in the mechanical and transport characteristics of fractured rock that result from coupled mechanical and chemical effects. The specific influence is the elevation of dissolution rates on contacting asperities, which results in a stress- and temperature-dependent permanent closure. A model representing this pressure-dissolution-like behavior is adapted to define the threshold and resulting response in terms of fundamental thermodynamic properties of a contacting fracture. These relations are incorporated in a stress-stiffening model of fracture closure to define the stress- and temperature-dependency of aperture loss and behavior during stress and temperature cycling. These models compare well with laboratory and field experiments, representing both decoupled isobaric and isothermal responses. The model was applied to explore the impact of these responses on heated structures in rock. The result showed a reduction in ultimate induced stresses over the case where chemical effects were not incorporated, with permanent reduction in final stresses after cooling to ambient conditions. Similarly, permeabilities may be lower than they were in the case where chemical effects were not considered, with a net reduction apparent even after cooling to ambient temperature. These heretofore-neglected effects may have a correspondingly significant impact on the performance of heated structures in rock, such as repositories for the containment of radioactive wastes.

  9. Modeling multiphase heat and mass transfer in consolidated, fractured, porous media

    SciTech Connect (OSTI)

    Bixler, N.E.; Eaton, R.R.

    1987-12-31T23:59:59.000Z

    A number of potential transport mechanisms are considered in this paper: Darcy flow due to pressure and density gradients in the liquid and gas phases; Knudsen diffusion in the gas phase; binary diffusion in the gas phase; heat conduction; energy convection; and evaporation/condensation and its associated latent heat effects. Most of these mechanisms are highly nonlinear, especially Darcy flow, where relative permeabilities often vary by orders of magnitude depending on local saturation, and evaporation/condensation, which depends strongly on local temperature, gas pressure, and saturation. As a consequence of the nonlinearities, it is essential to employ numerical methods if realistic modeling is to be performed. Here, the numerical model is of the standard Galerkin/finite element variety, which is convenient for handling irregular domains and a wide variety of boundary conditions. This numerical model is used to examine the relative effectiveness of each of the transport mechanisms in several one-dimensional and simple two-dimensional multiphase flows in fractured and unfractured porous materials. The importance of fracture orientation is also studied. Predictions are compared with experimental measurements for imbibition and drying of fractured volcanic tuff.

  10. Method of fracturing a geological formation

    DOE Patents [OSTI]

    Johnson, James O. (2679-B Walnut, Los Alamos, NM 87544)

    1990-01-01T23:59:59.000Z

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

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

    Open Energy Info (EERE)

    Regional Analysis And Characterization Of Fractured Aquifers In The Virginia Blue Ridge And Piedmont Provinces Jump to: navigation, search OpenEI Reference LibraryAdd to library...

  12. Wave Propagation in Fractured Poroelastic Media

    E-Print Network [OSTI]

    2014-06-22T23:59:59.000Z

    Wave Propagation in Fractured. Poroelastic Media. WCCM, Barcelona, Spain, July 2014. Juan E. Santos,. 1. 1. Instituto del Gas y del Petr´oleo (IGPUBA), UBA,

  13. Fracturing technology poised for rapid advancement

    SciTech Connect (OSTI)

    Von Flatern, R.

    1993-10-01T23:59:59.000Z

    This paper summarizes the advances and current status of hydraulic fracturing and the industry's ability to design and predict the results. Although modeling techniques have improved over the years, there still is no model which can be considered very reliable. The paper considers alternatives to help improve the reliability of these models such as on-site quality control. This quality control aspect entails the site-specific tailoring of a fracturing fluid to be better suited for the target fracturing zone environment and adjusting the fluid properties accordingly. It also entails various methods for fluid injection and placement of propping agents. Some future trends in hydraulic fracturing are also discussed.

  14. Geothermal: Sponsored by OSTI -- Fracture Characterization in...

    Office of Scientific and Technical Information (OSTI)

    Fracture Characterization in Enhanced Geothermal Systems by Wellbore and Reservoir Analysis Geothermal Technologies Legacy Collection HelpFAQ | Site Map | Contact Us | Admin Log...

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

    Broader source: Energy.gov (indexed) [DOE]

    5 4.5.2 Seismic Fracture Characterization Methods for Enhanced Geothermal Systems Presentation Number: 022 Investigator: Queen, John (Hi-Q Geophysical Inc.) Objectives: To develop...

  16. Microseismic Tracer Particles for Hydraulic Fracturing

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

    The trend toward production of hydrocarbons from unconventional reservoirs (tight gas, shale oilgas) has caused a large increase in the use of hydraulic fracture stimulation of...

  17. A comparative simulation study of coupled THM processes and their effect on fractured rock permeability around nuclear waste repositories

    E-Print Network [OSTI]

    Rutqvist, Jonny

    2008-01-01T23:59:59.000Z

    European countries. The initial rock properties for the twoinduced changes in rock properties. The purpose of the model3. Some basic THM rock properties Parameter Bulk Density, [

  18. The Role of Acidizing in Proppant Fracturing in Carbonate Reservoirs

    E-Print Network [OSTI]

    Densirimongkol, Jurairat

    2010-10-12T23:59:59.000Z

    in fracture conductivity and unsuccessful stimulation treatment. In early years, because of the increase in the success of proppant fracturing, proppant partial monolayer has been put forward as a method that helps generate the maximum fracture conductivity...

  19. Seismic characterization of fractured reservoirs using 3D double beams

    E-Print Network [OSTI]

    Zheng, Yingcai

    2012-01-01T23:59:59.000Z

    We propose an efficient target-oriented method to characterize seismic properties of fractured reservoirs: the spacing between fractures and the fracture orientation. We use both singly scattered and multiply scattered ...

  20. Efficient Double-Beam Characterization for Fractured Reservoir

    E-Print Network [OSTI]

    Zheng, Yingcai

    We proposed an efficient target-oriented method to characterize seismic properties of fractured reservoirs: the spacing between fractures and the fracture orientation. Based on the diffraction theory, the scattered wave ...

  1. Incorporating Rigorous Height Determination into Unified Fracture Design

    E-Print Network [OSTI]

    Pitakbunkate, Termpan

    2010-10-12T23:59:59.000Z

    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...

  2. Studying Hydraulic Fracturing through Time-variant Seismic Anisotropy

    E-Print Network [OSTI]

    Liu, Qifan

    2013-10-01T23:59:59.000Z

    . Studying seismic anisotropy by shear wave splitting can help us better understand the relationship between hydraulic fracturing and fracture systems. Shear wave splitting can be caused by fracturing and also can naturally take place in most sedimentary...

  3. Ductile fracture modeling : theory, experimental investigation and numerical verification

    E-Print Network [OSTI]

    Xue, Liang, 1973-

    2007-01-01T23:59:59.000Z

    The fracture initiation in ductile materials is governed by the damaging process along the plastic loading path. A new damage plasticity model for ductile fracture is proposed. Experimental results show that fracture ...

  4. INJECTION AND THERMAL BREAKTHROUGH IN FRACTURED GEOTHERMAL RESERVOIRS

    E-Print Network [OSTI]

    Bodvarsson, Gudmundur S.

    2012-01-01T23:59:59.000Z

    injection into a fractured reservoir system. A reservoirIn the case of fractured reservoirs, Equations (25) and (26)c ww q a >> For fractured reservoirs, the former expression

  5. Laboratory-scale fracture conductivity created by acid etching 

    E-Print Network [OSTI]

    Pournik, Maysam

    2009-05-15T23:59:59.000Z

    Success of acid fracturing treatment depends greatly on the created conductivity under closure stress. In order to have sufficient conductivity, the fracture face must be non-uniformly etched while the fracture strength maintained to withstand...

  6. Tubular hydrogen permeable metal foil membrane and method of fabrication

    DOE Patents [OSTI]

    Paglieri, Stephen N.; Birdsell, Stephen A.; Barbero, Robert S.; Snow, Ronny C.; Smith, Frank M.

    2006-04-04T23:59:59.000Z

    A tubular hydrogen permeable metal membrane and fabrication process comprises obtaining a metal alloy foil having two surfaces, coating the surfaces with a metal or metal alloy catalytic layer to produce a hydrogen permeable metal membrane, sizing the membrane into a sheet with two long edges, wrapping the membrane around an elongated expandable rod with the two long edges aligned and overlapping to facilitate welding of the two together, placing the foil wrapped rod into a surrounding fixture housing with the two aligned and overlapping foil edges accessible through an elongated aperture in the surrounding fixture housing, expanding the elongated expandable rod within the surrounding fixture housing to tighten the foil about the expanded rod, welding the two long overlapping foil edges to one another generating a tubular membrane, and removing the tubular membrane from within the surrounding fixture housing and the expandable rod from with the tubular membrane.

  7. Field-Scale Effective Matrix Diffusion Coefficient for Fractured Rock: Results From Literature Survey

    E-Print Network [OSTI]

    Zhou, Quanlin; Liu, Hui Hai; Molz, Fred J.; Zhang, Yingqi; Bodvarsson, Gudmundur S.

    2008-01-01T23:59:59.000Z

    Dispersed fluid flow in fractured reservoirs: An analysis ofa hydraulically fractured granite geothermal reservoir, Soc.

  8. Aligned vertical fractures, HTI reservoir symmetry, and Thomsen seismic anisotropy parameters

    E-Print Network [OSTI]

    Berryman, James G.

    2008-01-01T23:59:59.000Z

    seismic parameters for fractured reservoirs when the crackin a naturally fractured gas reservoir, The Leading Edge,

  9. An analysis of the accuracy of relative permeability 

    E-Print Network [OSTI]

    Tao, Teh-Ming

    1982-01-01T23:59:59.000Z

    Properties Used in Sample Study. . . 2. Summary of Cases Run 34 3. Summary of Sample Properties. 36 4. Comparison of the Relative Error 51 5. Error in Water Infection Rate. 57 6. Influence of Different Magnitude of Measurement Error. 75 LIST QF FIGURES.... Pressure Variation. 27 8. Simulated Measurement Errors. 31 Estimation Deviation Distribution of k for Cases 1, 5, 6, 7. 41 10 Estimation Deviation Distribution of k for Cases 1, 5, 6, 7. 42 Standard Deviation Distribution of Oil Relative Permeability...

  10. Semi-analytical estimates of permeability obtained from capillary pressure

    E-Print Network [OSTI]

    Huet, Caroline Cecile

    2006-04-12T23:59:59.000Z

    ..............................................................................................................................................(2.7) Where ? is the pore size distribution index. This model is commonly used for consolidated porous media. In 1980, Van Genuchten26 adopted a capillary pressure model to predict the hydraulic conductivity of unsaturated soils. Van... on permeability and its prediction ? the first part of the derivation follows the work of Wyllie and Gardner.3 Their model describes the porous media as a bundle of capillary tubes featuring a random connection of pore spaces. Some of the assumptions made are...

  11. Test device for measuring permeability of a barrier material

    DOE Patents [OSTI]

    Reese, Matthew; Dameron, Arrelaine; Kempe, Michael

    2014-03-04T23:59:59.000Z

    A test device for measuring permeability of a barrier material. An exemplary device comprises a test card having a thin-film conductor-pattern formed thereon and an edge seal which seals the test card to the barrier material. Another exemplary embodiment is an electrical calcium test device comprising: a test card an impermeable spacer, an edge seal which seals the test card to the spacer and an edge seal which seals the spacer to the barrier material.

  12. active fracture model: Topics by E-print Network

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

    porosity of naturally fractured reservoirs with no matrix porosity using stochastic fractal models Texas A&M University - TxSpace Summary: Determining fracture characteristics...

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

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

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

  14. Images of Fracture Sustainability Test on Stripa Granite

    SciTech Connect (OSTI)

    Tim Kneafsey

    2014-05-11T23:59:59.000Z

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

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

    Broader source: Energy.gov (indexed) [DOE]

    7 4.4.1 Detecting Fractures Using Technology at High Temperatures and Depths - Geothermal Ultrasonic Fracture Imager (GUFI) Presentation Number: 015 Investigator: Patterson, Doug...

  16. Images of Fracture Sustainability Test on Stripa Granite

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

    Tim Kneafsey

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

  17. acetabular internal fracture: Topics by E-print Network

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

    stiness and uid ow L Lafayette, IN 47907-1397, USA Accepted 7 October 1999 Abstract Fracture specic stiness and uid ow through a single fracture under...

  18. age fracture mechanics: Topics by E-print Network

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

    stiness and uid ow L Lafayette, IN 47907-1397, USA Accepted 7 October 1999 Abstract Fracture specic stiness and uid ow through a single fracture under...

  19. alloys fracture mechanics: Topics by E-print Network

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

    stiness and uid ow L Lafayette, IN 47907-1397, USA Accepted 7 October 1999 Abstract Fracture specic stiness and uid ow through a single fracture under...

  20. applying fracture mechanics: Topics by E-print Network

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

    stiness and uid ow L Lafayette, IN 47907-1397, USA Accepted 7 October 1999 Abstract Fracture specic stiness and uid ow through a single fracture under...

  1. advanced fracture characterization: Topics by E-print Network

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

    stiness and uid ow L Lafayette, IN 47907-1397, USA Accepted 7 October 1999 Abstract Fracture specic stiness and uid ow through a single fracture under...

  2. Identification of MHF Fracture Planes and Flow Paths- a Correlation...

    Open Energy Info (EERE)

    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...

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

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

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

  4. Monitoring of Fracture Cri0cal Steel Bridges

    E-Print Network [OSTI]

    Minnesota, University of

    #12;Monitoring of Fracture Cri0cal Steel Bridges: Acous0c Emission Sensors system on other fracture cri0cal steel bridges #12;Project Impact #12;Thank

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

    Broader source: Energy.gov (indexed) [DOE]

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

  6. Joint inversion of electrical and seismic data for Fracture char...

    Broader source: Energy.gov (indexed) [DOE]

    Joint inversion of electrical and seismic data for Fracture char. and Imaging of Fluid Flow in Geothermal Systems Joint inversion of electrical and seismic data for Fracture char....

  7. Thermal single-well injection-withdrawal tracer tests for determining fracture-matrix heat transfer area

    SciTech Connect (OSTI)

    Pruess, K.; Doughty, C.

    2010-01-15T23:59:59.000Z

    Single-well injection-withdrawal (SWIW) tracer tests involve injection of traced fluid and subsequent tracer recovery from the same well, usually with some quiescent time between the injection and withdrawal periods. SWIW are insensitive to variations in advective processes that arise from formation heterogeneities, because upon withdrawal, fluid parcels tend to retrace the paths taken during injection. However, SWIW are sensitive to diffusive processes, such as diffusive exchange of conservative or reactive solutes between fractures and rock matrix. This paper focuses on SWIW tests in which temperature itself is used as a tracer. Numerical simulations demonstrate the sensitivity of temperature returns to fracture-matrix interaction. We consider thermal SWIW response to the two primary reservoir improvements targeted with stimulation, (1) making additional fractures accessible to injected fluids, and (2) increasing the aperture and permeability of pre-existing fractures. It is found that temperature returns in SWIW tests are insensitive to (2), while providing a strong signal of more rapid temperature recovery during the withdrawal phase for (1).

  8. THERMO-HYDRO-MECHANICAL MODELING OF WORKING FLUID INJECTION AND THERMAL ENERGY EXTRACTION IN EGS FRACTURES AND ROCK MATRIX

    SciTech Connect (OSTI)

    Robert Podgorney; Chuan Lu; Hai Huang

    2012-01-01T23:59:59.000Z

    Development of enhanced geothermal systems (EGS) will require creation of a reservoir of sufficient volume to enable commercial-scale heat transfer from the reservoir rocks to the working fluid. A key assumption associated with reservoir creation/stimulation is that sufficient rock volumes can be hydraulically fractured via both tensile and shear failure, and more importantly by reactivation of naturally existing fractures (by shearing), to create the reservoir. The advancement of EGS greatly depends on our understanding of the dynamics of the intimately coupled rock-fracture-fluid-heat system and our ability to reliably predict how reservoirs behave under stimulation and production. Reliable performance predictions of EGS reservoirs require accurate and robust modeling for strongly coupled thermal-hydrological-mechanical (THM) processes. Conventionally, these types of problems have been solved using operator-splitting methods, usually by coupling a subsurface flow and heat transport simulators with a solid mechanics simulator via input files. An alternative approach is to solve the system of nonlinear partial differential equations that govern multiphase fluid flow, heat transport, and rock mechanics simultaneously, using a fully coupled, fully implicit solution procedure, in which all solution variables (pressure, enthalpy, and rock displacement fields) are solved simultaneously. This paper describes numerical simulations used to investigate the poro- and thermal- elastic effects of working fluid injection and thermal energy extraction on the properties of the fractures and rock matrix of a hypothetical EGS reservoir, using a novel simulation software FALCON (Podgorney et al., 2011), a finite element based simulator solving fully coupled multiphase fluid flow, heat transport, rock deformation, and fracturing using a global implicit approach. Investigations are also conducted on how these poro- and thermal-elastic effects are related to fracture permeability evolution.

  9. The averaging process in permeability estimation from well-test data

    SciTech Connect (OSTI)

    Oliver, D.S. (Saudi Aramco (SA))

    1990-09-01T23:59:59.000Z

    Permeability estimates from the pressure derivative or the slope of the semilog plot usually are considered to be averages of some large ill-defined reservoir volume. This paper presents results of a study of the averaging process, including identification of the region of the reservoir that influences permeability estimates, and a specification of the relative contribution of the permeability of various regions to the estimate of average permeability. The diffusion equation for the pressure response of a well situated in an infinite reservoir where permeability is an arbitrary function of position was solved for the case of small variations from a mean value. Permeability estimates from the slope of the plot of pressure vs. the logarithm of drawdown time are shown to be weighted averages of the permeabilities within an inner and outer radius of investigation.

  10. The effects of viscous forces on three-phase relative permeability

    SciTech Connect (OSTI)

    Maloney, D.R.; Mahmood, S.M.; Honarpour, M.M.

    1989-04-01T23:59:59.000Z

    The overall objective of Three-Phase Relative Permeability Project (BE9) is to develop guidelines for improving the accuracy of three-phase relative permeability determinations. This report summarizes previous studies and explains the progress made at NIPER on studying the effect of variations in viscous forces on three-phase relative permeabilities by changing the viscosity of both wetting and nonwetting phases. Significant changes were observed due to viscosity variations. An increase in oil viscosity reduced the relative permeability to gas; an increase in brine/(wetting-phase) viscosity reduced the relative permeability to brine. A slight increase in gas relative permeability was also observed. These observations suggest that the viscosities of both oil and water influence three-phase permeability data. During this study, data scatter was sometimes encountered which was comparable to that of published results. The causes of this scatter are outlined in this report and remedial attempts are discussed. 20 refs., 16 figs., 5 tabs.

  11. Modeling of Acid Fracturing in Carbonate Reservoirs

    E-Print Network [OSTI]

    Al Jawad, Murtada s

    2014-06-05T23:59:59.000Z

    equations are used to draw 3D velocity and pressure profiles. Part of the fluid diffuses or leaks off into the fracture walls and dissolves part of the fracture face according to the chemical reaction below. 2H^(+)(aq) + CO((2-)/3) ? H_(2 )CO_(3)(aq) ? CO...

  12. Accounting for Remaining Injected Fracturing Fluid 

    E-Print Network [OSTI]

    Zhang, Yannan

    2013-12-06T23:59:59.000Z

    The technology of multi-stage fracturing of horizontal wells made the development of shale gas reservoirs become greatly successful during the past decades. A large amount of fracturing fluid, usually from 53,000 bbls to 81,400 bbls, is injected...

  13. Accounting for Remaining Injected Fracturing Fluid

    E-Print Network [OSTI]

    Zhang, Yannan

    2013-12-06T23:59:59.000Z

    The technology of multi-stage fracturing of horizontal wells made the development of shale gas reservoirs become greatly successful during the past decades. A large amount of fracturing fluid, usually from 53,000 bbls to 81,400 bbls, is injected...

  14. Fracture of synthetic diamond M. D. Droty

    E-Print Network [OSTI]

    Ritchie, Robert

    of synthetic polycrystalline diamond make it a promising material for many structural applications studies on the fracture toughness of polycrystalline diamond,29 primarily due to the difficultiesFracture of synthetic diamond M. D. Droty Ctystallume, 3506 Bassett Street, Santa Clara, California

  15. Finite Conductivity Fractures in Elliptical Coordinates

    E-Print Network [OSTI]

    Stanford University

    TO THE DEPARTMENT OF PETROLEUM ENGINEERING AND THE COMMITTEE ON GRADUATE STUDIES OF STANFORD UNIVERSITY IN PARTIAL well performance. Indeed, a large number of wells, which could not otherwise be operated economically, it is important that means be available to evaluate fracture effectiveness. The most widely used tool in fracture

  16. FRACTURED RESERVOIR E&P IN ROCKY MOUNTAIN BASINS: A 3-D RTM MODELING APPROACH

    SciTech Connect (OSTI)

    P. Ortoleva; J. Comer; A. Park; D. Payne; W. Sibo; K. Tuncay

    2001-11-26T23:59:59.000Z

    Key natural gas reserves in Rocky Mountain and other U.S. basins are in reservoirs with economic producibility due to natural fractures. In this project, we evaluate a unique technology for predicting fractured reservoir location and characteristics ahead of drilling based on a 3-D basin/field simulator, Basin RTM. Recommendations are made for making Basin RTM a key element of a practical E&P strategy. A myriad of reaction, transport, and mechanical (RTM) processes underlie the creation, cementation and preservation of fractured reservoirs. These processes are often so strongly coupled that they cannot be understood individually. Furthermore, sedimentary nonuniformity, overall tectonics and basement heat flux histories make a basin a fundamentally 3-D object. Basin RTM is the only 3-D, comprehensive, fully coupled RTM basin simulator available for the exploration of fractured reservoirs. Results of Basin RTM simulations are presented, that demonstrate its capabilities and limitations. Furthermore, it is shown how Basin RTM is a basis for a revolutionary automated methodology for simultaneously using a range of remote and other basin datasets to locate reservoirs and to assess risk. Characteristics predicted by our model include reserves and composition, matrix and fracture permeability, reservoir rock strength, porosity, in situ stress and the statistics of fracture aperture, length and orientation. Our model integrates its input data (overall sedimentation, tectonic and basement heat flux histories) via the laws of physics and chemistry that describe the RTM processes to predict reservoir location and characteristics. Basin RTM uses 3-D, finite element solutions of the equations of rock mechanics, organic and inorganic diagenesis and multi-phase hydrology to make its predictions. As our model predicts reservoir characteristics, it can be used to optimize production approaches (e.g., assess the stability of horizontal wells or vulnerability of fractures to production-induced formation pressure drawdown). The Piceance Basin (Colorado) was chosen for this study because of the extensive set of data provided to us by federal agencies and industry partners, its remaining reserves, and its similarities with other Rocky Mountain basins. We focused on the Rulison Field to test our ability to capture details in a well-characterized area. In this study, we developed a number of general principles including (1) the importance of even subtle flexure in creating fractures; (2) the tendency to preserve fractures due to the compressibility of gases; (3) the importance of oscillatory fracture/flow cycles in the expulsion of natural gas from source rock; and (4) that predicting fractures requires a basin model that is comprehensive, all processes are coupled, and is fully 3-D. A major difficulty in using Basin RTM or other basin simulator has been overcome in this project; we have set forth an information theory technology for automatically integrating basin modeling with classical database analysis; this technology also provides an assessment of risk. We have created a relational database for the Piceance Basin. We have developed a formulation of devolatilization shrinkage that integrates organic geochemical kinetics into incremental stress theory, allowing for the prediction of coal cleating and associated enhancement of natural gas expulsion from coal. An estimation of the potential economic benefits of the technologies developed or recommended here is set forth. All of the above findings are documented in this report.

  17. Quantifying AGN-Driven Metal-Enhanced Outflows in Chemodynamical Simulations

    E-Print Network [OSTI]

    Taylor, Philip

    2015-01-01T23:59:59.000Z

    We show the effects of AGN-driven outflows on the ejection of heavy elements using our cosmological simulations, where super-massive black holes originate from the first stars. In the most massive galaxy, we have identified two strong outflows unambiguously driven by AGN feedback. These outflows have a speed greater than $\\sim 8000$ km\\,s$^{-1}$ near the AGN, and travel out to a half Mpc with $\\sim 3000$ km\\,s$^{-1}$. These outflows remove the remaining gas ($\\sim 3$ per cent of baryons) and significant amounts of metals ($\\sim 2$ per cent of total produced metals) from the host galaxy, chemically enriching the circumgalactic medium (CGM) and the intergalactic medium (IGM). 17.6 per cent of metals from this galaxy, and 18.4 per cent of total produced metals in the simulation, end up in the CGM and IGM, respectively. The metallicities of the CGM and IGM are higher with AGN feedback, while the mass--metallicity relation of galaxies is not affected very much. We also find `selective' mass-loss where iron is more...

  18. Biomass burning emission inventory with daily resolution: Application to aircraft observations of Asian outflow

    E-Print Network [OSTI]

    Palmer, Paul

    Biomass burning emission inventory with daily resolution: Application to aircraft observations for biomass burning using AVHRR satellite observations of fire activity corrected for data gaps and scan angle biomass burning in SE Asia was a major contributor to the outflow of Asian pollution observed in TRACE

  19. On the thermodynamic boundary conditions of a solidifying mushy layer with outflow

    E-Print Network [OSTI]

    Rees Jones, David W.; Worster, M. Grae

    2014-11-27T23:59:59.000Z

    –207. Thermodynamic boundary conditions with outflow 11 Beckermann, C. & Wang, C.Y. 1995 Multiphase/-scale modeling of alloy solidification. In Annual Reviews of Heat Transfer (ed. C. L. Tien), vol. 6, pp. 115–198. Begell House. Conroy, D. & Worster, M. G. 2006 Mush...

  20. Title of Dissertation: Outflows in Infrared-Luminous Galaxies: Absorption-Line Spectroscopy

    E-Print Network [OSTI]

    Gruner, Daniel S.

    Abstract Title of Dissertation: Outflows in Infrared-Luminous Galaxies: Absorption performed a survey of over 100 infrared-luminous galaxies in or- der to address the exact frequency galaxies, and their proper- ties in the most luminous starburst and active galaxies. Most of our sample

  1. The effect of drier outflow temperature on rumen protein degradability and intestinal digestibility of rumen-

    E-Print Network [OSTI]

    Paris-Sud XI, Université de

    of rumen- undegraded protein of dehydrated grass and lucerne ZM Kowalski PMP Pisulewski2 JL Peyraud J was to determine the effect of drier outflow temperature (123, 133, 143 and 153°C) on dehydrated grass and lucerne and increased ADIN % N in dehydrated grass. These tendencies were not seen for dehydrated lucerne. Temperature

  2. Chemical Abundances in AGN Environment: X-Ray/UV Campaign on the MRK 279 Outflow

    E-Print Network [OSTI]

    Nahum Arav; Jack R. Gabel; Kirk T. Korista; Jelle S. Kaastra; Gerard A. Kriss; Ehud Behar; Elisa Costantini; C. Martin Gaskell; Ari Laor; Nalaka Kodituwakku; Daniel Proga; Masao Sako; Jennifer E. Scott; Katrien C. Steenbrugge

    2006-11-29T23:59:59.000Z

    We present the first reliable determination of chemical abundances in an AGN outflow. The abundances are extracted from the deep and simultaneous FUSE and HST/STIS observations of Mrk 279. This data set is exceptional for its high signal-to-noise, unblended doublet troughs and little Galactic absorption contamination. These attributes allow us to solve for the velocity-dependent covering fraction, and therefore obtain reliable column densities for many ionic species. For the first time we have enough such column densities to simultaneously determine the ionization equilibrium and abundances in the flow. Our analysis uses the full spectral information embedded in these high-resolution data. Slicing a given trough into many independent outflow elements yields the extra constraints needed for a physically meaningful abundances determination. We find that relative to solar the abundances in the Mrk 279 outflow are (linear scaling): carbon 2.2+/-0.7, nitrogen 3.5+/-1.1 and oxygen 1.6+/-0.8. Our UV-based photoionization and abundances results are in good agreement with the independent analysis of the simultaneous Mrk 279 X-ray spectra. This is the best agreement between the UV and X-ray analyses of the same outflow to date.

  3. Measurements of Outflow Velocities in On-Disk Plumes from EIS Hinode Observations

    E-Print Network [OSTI]

    Fu, Hui; Li, Bo; Huang, Zhenghua; Jiao, Fangran; Mou, Chaozhou

    2014-01-01T23:59:59.000Z

    The contribution of plumes to the solar wind has been subject to hot debate in the past decades. The EUV Imaging Spectrometer (EIS) on board Hinode provides a unique means to deduce outflow velocities at coronal heights via direct Doppler shift measurements of coronal emission lines. Such direct Doppler shift measurements were not possible with previous spectrometers. We measure the outflow velocity at coronal heights in several on-disk long-duration plumes, which are located in coronal holes and show significant blue shifts throughout the entire observational period. In one case, a plume is measured 4 hours apart. The deduced outflow velocities are consistent, suggesting that the flows are quasi-steady. Furthermore, we provide an outflow velocity profile along the plumes, finding that the velocity corrected for the line-of-sight effect can reach 10 km s$^{-1}$ at 1.02 $R_{\\odot}$, 15 km s$^{-1}$ at 1.03 $R_{\\odot}$, and 25 km s$^{-1}$ at 1.05 $R_{\\odot}$. This clear signature of steady acceleration, combined...

  4. Improved quantification of Chinese carbon fluxes using CO2//CO correlations in Asian outflow

    E-Print Network [OSTI]

    Palmer, Paul

    increases in Chinese anthropogenic CO2 emissions and would also imply a further reduction of the Chinese budget including, in particular, Chinese emissions. The CO2/CO emission ratio varies with the sourceImproved quantification of Chinese carbon fluxes using CO2//CO correlations in Asian outflow

  5. Hydraulic fracturing slurry transport in horizontal pipes

    SciTech Connect (OSTI)

    Shah, S.N.; Lord, D.L. (Halliburton Services (US))

    1990-09-01T23:59:59.000Z

    Horizontal-well activity has increased throughout the industry in the past few years. To design a successful hydraulic fracturing treatment for horizontal wells, accurate information on the transport properties of slurry in horizontal pipe is required. Limited information exists that can be used to estimate critical deposition and resuspension velocities when proppants are transported in horizontal wells with non-Newtonian fracturing gels. This paper presents a study of transport properties of various hydraulic fracturing slurries in horizontal pipes. Flow data are gathered in three transparent horizontal pipes with different diameters. Linear and crosslinked fracturing gels were studied, and the effects of variables--e.g., pipe size; polymer-gelling-agent concentration; fluid rheological properties; crosslinking effects; proppant size, density, and concentrations; fluid density; and slurry pump rate--on critical deposition and resuspension velocities were investigated. Also, equations to estimate the critical deposition and resuspension velocities of fracturing gels are provided.

  6. Methodologies and new user interfaces to optimize hydraulic fracturing design and evaluate fracturing performance for gas wells 

    E-Print Network [OSTI]

    Wang, Wenxin

    2006-04-12T23:59:59.000Z

    This thesis presents and develops efficient and effective methodologies for optimal hydraulic fracture design and fracture performance evaluation. These methods incorporate algorithms that simultaneously optimize all of ...

  7. Development of a Neutron Diffraction Based Experiemental Capability for Investigating Hydraulic Fracturing for EGS-like Conditions

    SciTech Connect (OSTI)

    Polsky, Yarom [ORNL] [ORNL; Anovitz, Lawrence {Larry} M [ORNL; An, Ke [ORNL] [ORNL; Carmichael, Justin R [ORNL] [ORNL; Bingham, Philip R [ORNL] [ORNL; Dessieux Jr, Luc Lucius [ORNL] [ORNL

    2013-01-01T23:59:59.000Z

    Hydraulic fracturing to enhance formation permeability is an established practice in the Oil & Gas (O&G) industry and is expected to be an enabler for EGS. However, it is rarely employed in conventional geothermal systems and there are significant questions regarding the translation of practice from O&G to both conventional geothermal and EGS applications. Lithological differences(sedimentary versus crystalline rocks, significantly greater formation temperatures and different desired fracture characteristics are among a number of factors that are likely to result in a gap of understanding of how to manage hydraulic fracturing practice for geothermal. Whereas the O&G community has had both the capital and the opportunity to develop its understanding of hydraulic fracturing operations empirically in the field as well through extensive R&D efforts, field testing opportunities for EGS are likely to be minimal due to the high expense of hydraulic fracturing field trials. A significant portion of the knowledge needed to guide the management of geothermal/EGS hydraulic fracturing operations will therefore likely have to come from experimental efforts and simulation. This paper describes ongoing efforts at Oak Ridge National Laboratory (ORNL) to develop an experimental capability to map the internal stresses/strains in core samples subjected to triaxial stress states and temperatures representative of EGS-like conditions using neutron diffraction based strain mapping techniques. This capability is being developed at ORNL\\'s Spallation Neutron Source, the world\\'s most powerful pulsed neutron source and is still in a proof of concept phase. A specialized pressure cell has been developed that permits independent radial and axial fluid pressurization of core samples, with axial flow through capability and a temperature rating up to 300 degrees C. This cell will ultimately be used to hydraulically pressurize EGS-representative core samples to conditions of imminent fracture and map the associated internal strain states of the sample. This will hopefully enable a more precise mapping of the rock material failure envelope, facilitate a more refined understanding of the mechanism of hydraulically induced rock fracture, particularly in crystalline rocks, and serve as a platform for validating and improving fracture simulation codes. The elements of the research program and preliminary strain mapping results of a Sierra White granite sample subjected only to compressive loading will be discussed in this paper.

  8. State-Of-The-Art in Permeability Determination From Well Log Data: Part 2-Verifiable, Accurate Permeability Predictions, the Touch-Stone of All Models

    E-Print Network [OSTI]

    Mohaghegh, Shahab

    SPE 30979 State-Of-The-Art in Permeability Determination From Well Log Data: Part 2- Verifiable prediction from well log data, is accurate and verifiable prediction of permeability for wells from which only the well log data is available. So far all the available models and techniques have been tried

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

    SciTech Connect (OSTI)

    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

    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.

  10. Fracture-resistant lanthanide scintillators

    DOE Patents [OSTI]

    Doty, F. Patrick (Livermore, CA)

    2011-01-04T23:59:59.000Z

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

  11. High Energy Gas Fracturing Test

    SciTech Connect (OSTI)

    Schulte, R.

    2001-02-27T23:59:59.000Z

    The Rocky Mountain Oilfield Testing Center (RMOTC) has recently completed two tests of a high-energy gas fracturing system being developed by Western Technologies of Crossville, Tennessee. The tests involved the use of two active wells located at the Naval Petroleum Reserve No. 3 (NPR-3), thirty-five miles north of Casper, Wyoming (See Figure 1). During the testing process the delivery and operational system was enhanced by RMOTC, Western Technologies, and commercial wireline subcontractors. RMOTC has assisted an industrial client in developing their technology for high energy gas fracturing to a commercial level. The modifications and improvements implemented during the technology testing process are instrumental in all field testing efforts at RMOTC. The importance of well selection can also be critical in demonstrating the success of the technology. To date, significant increases in well productivity have been clearly proven in well 63-TPX-10. Gross fluid production was initially raised by a factor of three. Final production rates increased by a factor of six with the use of a larger submersible pump. Well productivity (bbls of fluid per foot of drawdown) increased by a factor of 15 to 20. The above results assume that no mechanical damage has occurred to the casing or cast iron bridge plug which could allow well production from the Tensleep ''B'' sand. In the case of well 61-A-3, a six-fold increase in total fluid production was seen. Unfortunately, the increase is clouded by the water injection into the well that was necessary to have a positive fluid head on the propellant tool. No significant increase in oil production was seen. The tools which were retrieved from both 63-TPX-10 and 61-A-3 indicated a large amount of energy, similar to high gram perforating, had been expended downhole upon the formation face.

  12. Coupling schemes for modeling hydraulic fracture propagation using the XFEM

    E-Print Network [OSTI]

    Peirce, Anthony

    Coupling schemes for modeling hydraulic fracture propagation using the XFEM Elizaveta Gordeliy of hydraulic fractures in an elastic medium. With appropriate enrichment, the XFEM resolves the Neumann(h) accuracy. For hydraulic fracture problems with a lag separating the uid front from the fracture front, we

  13. Calibration of hydraulic and tracer tests in fractured media

    E-Print Network [OSTI]

    Politècnica de Catalunya, Universitat

    Calibration of hydraulic and tracer tests in fractured media represented by a DFN Model L. D. Donado, X. Sanchez-Vila, E. Ruiz* & F. J. Elorza** * Enviros Spain S.L. ** UPM #12;Fractured Media Water flows through fractures (matrix basically impervious ­ though relevant to transport) Fractures at all

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

    E-Print Network [OSTI]

    Correa Castro, Juan

    2011-08-08T23:59:59.000Z

    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...

  15. Liquid Spills on Permeable Soil Surfaces: Experimental Confirmations

    SciTech Connect (OSTI)

    Simmons, Carver S.; Keller, Jason M.

    2005-09-29T23:59:59.000Z

    Predictive tools for assessing the quantity of a spill on a soil from the observed spreading area could contribute to improving remediation when it is necessary. On a permeable soil, the visible spill area only hints about the amount of liquid that might reside below the surface. An understanding of the physical phenomena involved with spill propagation on a soil surface is key to assessing the liquid amount possibly present beneath the surface. The objective of this study is an improved prediction capability for spill behavior.

  16. Permeability of CoNbZr amorphous thin films over a wide frequency range

    SciTech Connect (OSTI)

    Koyama, H.; Tsujimoto, H.; Shirae, K.

    1987-09-01T23:59:59.000Z

    CoNbZr amorphous films have attracted the attention of many researchers because of their high saturation magnetization, high permeability, low coercivity, and nearly zero magnetostriction. For these films to be used, one of the important magnetic properties is the behavior of the permeability over a wide frequency range. We have measured the permeability of a square-shaped magnetic film (13 mm x 55 mm) sputtered on a glass substrate from 1 MHz to 400 MHz using a stripline. Over 400 MHz, the permeability of the magnetic film was measured using a ring-shaped sample mounted in a coaxial fixture. The wall motion permeability of CoNbZr amorphous films decreases from 1 kHz to nearly zero at 1 MHz. The rotation permeability is constant to 100 MHz and ferromagnetic resonance is observed near 1 GHz.

  17. 3-D description of fracture surfaces and stress-sensitivity analysis for naturally fractured reservoirs

    SciTech Connect (OSTI)

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

    1997-08-01T23:59:59.000Z

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

  18. Percutaneous Vertebroplasty for Osteoporotic Compression Fracture: Multivariate Study of Predictors of New Vertebral Body Fracture

    SciTech Connect (OSTI)

    Komemushi, Atsushi, E-mail: kome64@yo.rim.or.jp; Tanigawa, Noboru; Kariya, Shuji; Kojima, Hiroyuki; Shomura, Yuzo [Kansai Medical University, Department of Radiology (Japan); Komemushi, Sadao [Kinki University, Schoool of Agriculture (Japan); Sawada, Satoshi [Kansai Medical University, Department of Radiology (Japan)

    2006-08-15T23:59:59.000Z

    Purpose. To investigate the risk factors and relative risk of new compression fractures following vertebroplasty. Methods. Initially, we enrolled 104 consecutive patients with vertebral compression fractures caused by osteoporosis. A total of 83 of the 104 patients visited our hospital for follow-up examinations for more than 4 weeks after vertebroplasty. Logistic regression analysis of the data obtained from these 83 patients was used to determine relative risks of recurrent compression fractures, using 13 different factors. Results. We identified 59 new fractures in 30 of the 83 patients: 41 new fractures in vertebrae adjacent to treated vertebrae; and 18 new fractures in vertebrae not adjacent to treated vertebrae. New fractures occurred in vertebrae adjacent to treated vertebrae significantly more frequently than in vertebrae not adjacent to treated vertebrae. Only cement leakage into the disk was a significant predictor of new vertebral body fracture after vertebroplasty (odds ratio = 4.633). None of the following covariates were associated with increased risk of new fracture: age, gender, bone mineral density, the number of vertebroplasty procedures, the number of vertebrae treated per procedure, the cumulative number of vertebrae treated, the presence of a single untreated vertebra between treated vertebrae, the presence of multiple untreated vertebrae between treated vertebrae, the amount of bone cement injected per procedure, the cumulative amount of bone cement injected, cement leakage into the soft tissue around the vertebra, and cement leakage into the vein.

  19. Universal asymptotic umbrella for hydraulic fracture modeling

    E-Print Network [OSTI]

    Linkov, Aleksandr M

    2014-01-01T23:59:59.000Z

    The paper presents universal asymptotic solution needed for efficient modeling of hydraulic fractures. We show that when neglecting the lag, there is universal asymptotic equation for the near-front opening. It appears that apart from the mechanical properties of fluid and rock, the asymptotic opening depends merely on the local speed of fracture propagation. This implies that, on one hand, the global problem is ill-posed, when trying to solve it as a boundary value problem under a fixed position of the front. On the other hand, when properly used, the universal asymptotics drastically facilitates solving hydraulic fracture problems (both analytically and numerically). We derive simple universal asymptotics and comment on their employment for efficient numerical simulation of hydraulic fractures, in particular, by well-established Level Set and Fast Marching Methods.

  20. Gas condensate damage in hydraulically fractured wells

    E-Print Network [OSTI]

    Adeyeye, Adedeji Ayoola

    2004-09-30T23:59:59.000Z

    Company. The well was producing a gas condensate reservoir and questions were raised about how much drop in flowing bottomhole pressure below dewpoint would be appropriate. Condensate damage in the hydraulic fracture was expected to be of significant...

  1. Geomechanical review of hydraulic fracturing technology

    E-Print Network [OSTI]

    Arop, Julius Bankong

    2013-01-01T23:59:59.000Z

    Hydraulic fracturing as a method for recovering unconventional shale gas has been around for several decades. Significant research and improvement in field methods have been documented in literature on the subject. The ...

  2. Fracture induced anisotropy in viscoelastic media

    E-Print Network [OSTI]

    santos,,,

    pp = 28 MPa, Z. ?1. N. = (14.4+3.6i) GPa, Z. ?1. T. = (21 + 2.6i) GPa,. We consider a set of equispaced fractures with L = 1 cm and 80 % binary fractal variations ...

  3. Multiphase flow in fractured porous media

    SciTech Connect (OSTI)

    Firoozabadi, A.

    1995-02-01T23:59:59.000Z

    The major goal of this research project was to improve the understanding of the gas-oil two-phase flow in fractured porous media. In addition, miscible displacement was studied to evaluate its promise for enhanced recovery.

  4. Dynamic Fracture Toughness of Polymer Composites

    E-Print Network [OSTI]

    Harmeet Kaur

    2012-02-14T23:59:59.000Z

    bar with required instrumentation to obtain load-history and initiation of crack propagation parameters followed by finite element analysis to determine desired dynamic properties. Single edge notch bend(SENB) type geometry is used for Mode-I fracture...

  5. Infiltration and Seepage Through Fractured Welded Tuff

    SciTech Connect (OSTI)

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

    2006-06-20T23:59:59.000Z

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

  6. Anomalous transport through porous and fractured media

    E-Print Network [OSTI]

    Kang, Peter Kyungchul

    2014-01-01T23:59:59.000Z

    Anomalous transport, understood as the nonlinear scaling with time of the mean square displacement of transported particles, is observed in many physical processes, including contaminant transport through porous and fractured ...

  7. anion-cation permeability correlates: Topics by E-print Network

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

    outside cell High water Rose, Michael R. 16 Improved permeability prediction using multivariate analysis methods Texas A&M University - TxSpace Summary: . In statistics,...

  8. Effects of confining pressure, pore pressure and temperature on absolute permeability. SUPRI TR-27

    SciTech Connect (OSTI)

    Gobran, B.D.; Ramey, H.J. Jr.; Brigham, W.E.

    1981-10-01T23:59:59.000Z

    This study investigates absolute permeability of consolidated sandstone and unconsolidated sand cores to distilled water as a function of the confining pressure on the core, the pore pressure of the flowing fluid and the temperature of the system. Since permeability measurements are usually made in the laboratory under conditions very different from those in the reservoir, it is important to know the effect of various parameters on the measured value of permeability. All studies on the effect of confining pressure on absolute permeability have found that when the confining pressure is increased, the permeability is reduced. The studies on the effect of temperature have shown much less consistency. This work contradicts the past Stanford studies by finding no effect of temperature on the absolute permeability of unconsolidated sand or sandstones to distilled water. The probable causes of the past errors are discussed. It has been found that inaccurate measurement of temperature at ambient conditions and non-equilibrium of temperature in the core can lead to a fictitious permeability reduction with temperature increase. The results of this study on the effect of confining pressure and pore pressure support the theory that as confining pressure is increased or pore pressure decreased, the permeability is reduced. The effects of confining pressure and pore pressure changes on absolute permeability are given explicitly so that measurements made under one set of confining pressure/pore pressure conditions in the laboratory can be extrapolated to conditions more representative of the reservoir.

  9. Techniques to Handle Limitations in Dynamic Relative Permeability Measurements, SUPRI TR-128

    SciTech Connect (OSTI)

    Qadeer, Suhail; Brigham, William E.; Castanier, Louis M.

    2002-10-08T23:59:59.000Z

    The objective of this work was to understand the limitations of the conventional methods of calculating relative permeabilities from data obtained from displacement experiments.

  10. Liquid CO2 Displacement of Water in a Dual-Permeability Pore...

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

    Permeability contrasts exist in multilayer geological formations under consideration for carbon sequestration. To improve our understanding of heterogeneous pore-scale...

  11. The role of geology in the behavior and choice of permeability predictors

    SciTech Connect (OSTI)

    Ball, L.D.; Corbett, P.W.M.; Jensen, J.L.; Lewis, J.J.M. [Heriot-Watt Univ., Edinburgh (United Kingdom)

    1997-03-01T23:59:59.000Z

    For effective flow-simulation models, it may be important to estimate permeability accurately over several scales of geological heterogeneity. Critical to the data analysis and permeability prediction are the volume of investigation and sampling interval of each petrophysical tool and how each relates to these geological scales. The authors examine these issues in the context of the As Sarah Field, Sirte Basin, Libya. A geological study of this braided fluvial reservoir has revealed heterogeneity at a series of scales. This geological hierarchy in turn possessed a corresponding hierarchy of permeability variation.The link between the geology and permeability was found to be very important in understanding well logs and core data and subsequent permeability upscaling. They found that the small scale (cm) permeability variability was better predicted using a flushed-zone resistivity, R{sub xo}, tool, rather than a wireline porosity measurement. The perm-resistivity correlation was strongest when the probe permeabilities were averaged to best match the window size of the wireline R{sub xo}. This behavior was explained by the geological variation present at this scale. For the larger scale geological heterogeneity, the production flowmeter highlighted discrepancies between flow data and averaged permeability. This yielded a layered sedimentological model interpretation and a change in averaging for permeability prediction at the bedset scale (ms-10 x ms).

  12. Semi-permeable vesicles composed of natural clay

    E-Print Network [OSTI]

    Anand B. Subramaniam; Jiandi Wan; Arvind Gopinath; Howard A. Stone

    2010-11-22T23:59:59.000Z

    We report a simple route to form robust, inorganic, semi-permeable compartments composed of montmorillonite, a natural plate-like clay mineral that occurs widely in the environment. Mechanical forces due to shear in a narrow gap assemble clay nanoplates from an aqueous suspension onto air bubbles. Translucent vesicles suspended in a single-phase liquid are produced when the clay-covered air bubbles are exposed to a variety of water-miscible organic liquids. These vesicles of clay are mechanically robust and are stable in water and other liquids. The formation of clay vesicles can be described by a physical mechanism that recognizes changes in the wetting characteristics of clay-covered air bubbles in organic liquids. The clay vesicles are covered with small pores and so intrinsically exhibit size-selective permeability, which allows spontaneous compartmentalization of self-assembling molecules in aqueous environments. The results we report here expand our understanding of potential paths to micro-compartmentalization in natural settings and are of relevance to theories of colloidal aggregation, mineral cycles, and the origins of life.

  13. Radio Flares of Compact Binary Mergers: the Effect of Non-Trivial Outflow Geometry

    E-Print Network [OSTI]

    Margalit, Ben

    2015-01-01T23:59:59.000Z

    The next generation gravitational waves (GW) detectors are most sensitive to GW emitted by compact (neutron star/black hole) binary mergers. If one of those is a neutron star the merger will also emit electromagnetic radiation via three possible channels: Gamma-ray bursts and their (possibly orphan) afterglows (Eichler et al. 1989), Li-Paczynski Macronovae (Li & Paczynski 1998) and radio flares (Nakar & Piran 2011). This accompanying electromagnetic radiation is vitally important in confirming the GW detections (Kochanek & Piran 1993). It could also reveal a wealth of information regarding the merger and will open a window towards multi-messenger astronomy. Identifying and characterizing these counterparts is therefore of utmost importance. In this work we explore late time radio flares emitted by the dynamically ejected outflows. We build upon previous work and consider the effect of the outflow's non-trivial geometry. Using an approximate method we estimate the radio light-curves for several eje...

  14. Feedback and its Feedback Effect on Feedback: Photoionization Suppression and its Impact on Galactic Outflows

    E-Print Network [OSTI]

    Matthew M. Pieri; Hugo Martel

    2007-05-02T23:59:59.000Z

    We show that radiative feedback due to reionization has a pronounced effect on the extent of mechanical feedback due to galactic outflows. The photoionization of the Intergalactic Medium (IGM) suppresses low-mass galaxy formation by photoheating the gas and limiting atomic line cooling. The number of low-mass galaxies is central for the enrichment of the IGM as these objects have the capacity to enrich a significant fraction (by volume) of the Universe. We use a modified version of our galactic outflow model, combined with a simple criterion for suppression, to investigate the potential impact upon the IGM. We find that this suppression strongly reduces the enrichment of the IGM and is sensitive to the reionization history. We also investigate the contribution of halos of different masses with varying degrees of suppression.

  15. Power-law scaling of asymmetries in viscous flow with PT-symmetric inflow and outflow

    E-Print Network [OSTI]

    Huidan; Yu; Xi Chen; Yousheng Xu; Yogesh N. Joglekar

    2014-10-13T23:59:59.000Z

    In recent years, open systems with balanced loss and gain, that are invariant under the combined parity and time-reversal ($\\mathcal{PT}$) operations, have been studied via asymmetries of their solutions. They represent systems as diverse as coupled optical waveguides and electrical or mechanical oscillators. We numerically investigate the asymmetries of incompressible viscous flow in two and three dimensions with "balanced" inflow-outflow ($\\mathcal{PT}$-symmetric) configurations. By introducing configuration-dependent classes of asymmetry functions in velocity, kinetic energy density, and vorticity fields, we find that the flow asymmetries exhibit power-law scaling with a single exponent in the laminar regime with the Reynolds number ranging over four decades. We show that such single-exponent scaling is expected for small Reynolds numbers, although its robustness at large values of Reynolds numbers is unexpected. Our results imply that $\\mathcal{PT}$-symmetric inflow-outflow configurations provide a hitherto unexplored avenue to tune flow properties.

  16. Formation of Compact Stellar Clusters by High-Redshift Galaxy Outflows I: Nonequillibrium Coolant Formation

    E-Print Network [OSTI]

    Gray, William J

    2010-01-01T23:59:59.000Z

    We use high-resolution three-dimensional adaptive mesh refinement simulations to investigate the interaction of high-redshift galaxy outflows with low-mass virialized clouds of primordial composition. While atomic cooling allows star formation in objects with virial temperatures above $10^4$ K, "minihaloes" below this threshold are generally unable to form stars by themselves. However, these objects are highly susceptible to triggered star formation, induced by outflows from neighboring high-redshift starburst galaxies. Here we conduct a study of these interactions, focusing on cooling through non-equilibrium molecular hydrogen (H$_2$) and hydrogen deuteride (HD) formation. Tracking the non-equilibrium chemistry and cooling of 14 species and including the presence of a dissociating background, we show that shock interactions can transform minihaloes into extremely compact clusters of coeval stars. Furthermore, these clusters are all less than $\\approx 10^6 M_\\odot,$ and they are ejected from their parent dark...

  17. Keck High-Resolution Spectroscopy of Outflows in Infrared Luminous Galaxies

    E-Print Network [OSTI]

    David S. Rupke; Sylvain Veilleux

    2005-09-05T23:59:59.000Z

    Several recent studies have determined that large quantities of neutral gas are outflowing from the nuclei of almost all infrared-luminous galaxies. These measurements show that winds in infrared-luminous galaxies play a significant role in the evolution of galaxies and the intergalactic medium at redshifts z > 1, when infrared-luminous galaxies dominated the star formation rate of the universe. These conclusions rely on moderate resolution spectra (FWHM > 65 km/s) of the NaI D absorption line and the assumption that there are no unresolved, saturated velocity components. For the first time, we present high resolution spectra (FWHM = 13 km/s) of massive, infrared-luminous galaxies. The five galaxies in our sample are known to host outflows on the basis of previous observations. With the present observations, all NaI D velocity components are resolved with tau(NaI D1 5896 A) luminous galaxies have been measured correctly by previous studies.

  18. STRONG MOLECULAR HYDROGEN EMISSION AND KINEMATICS OF THE MULTIPHASE GAS IN RADIO GALAXIES WITH FAST JET-DRIVEN OUTFLOWS

    E-Print Network [OSTI]

    Guillard, P.

    Observations of ionized and neutral gas outflows in radio galaxies (RGs) suggest that active galactic nucleus (AGN) radio jet feedback has a galaxy-scale impact on the host interstellar medium, but it is still unclear how ...

  19. Surface circulation in the Gulf of Cadiz: 2. Inflow-outflow coupling and the Gulf of Cadiz slope

    E-Print Network [OSTI]

    Brest, Université de

    that of the atmospheric forcing in driving the upper slope currents. The Mediteranean outflow forces a surface open ocean filaments con- touring Cape St. Vincent and penetrating eastward into the warmer GoC waters that suggest

  20. Fracture Conductivity of the Eagle Ford Shale

    E-Print Network [OSTI]

    Guzek, James J

    2014-07-25T23:59:59.000Z

    , and rock geomechanical properties. Therefore, optimizing conductivity by tailoring a well’s fracturing treatment to local reservoir characteristics is important to the oil and gas industry for economic reasons. The roots of hydraulic fracturing can... of the formation. Sahoo et al. (2013) identified that mineralogy, hydrocarbon filled porosity, and total organic content are most prominent parameters that control Eagle Ford well productivity. Mineral composition determines several geomechanical properties...