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1

Finding Large Aperture Fractures in Geothermal Resource Areas...  

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

Seismic Survey DOE Geothermal Peer Review 2010 - Presentation. Project summary: Drilling into large aperture open fractures (LAFs) typically yield production wells with...

2

Finding Large Aperture Fractures in Geothermal Resource Areas Using a  

Open Energy Info (EERE)

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

3

Finding Large Aperture Fractures in Geothermal Resource Areas Using a Three-Component Long-Offset Surface Seismic Survey  

Broader source: Energy.gov [DOE]

DOE Geothermal Peer Review 2010 - Presentation. Project summary: Drilling into large aperture open fractures (LAFs) typically yield production wells with high productivity and low pressure drawdown. Developing geophysical and geologic techniques for identifying and precisely mapping LAFsin 3-D will greatly reduce dry hole risk and the overall number of wells required for reaching a particular geothermal field power capacity.

4

Finding Large Aperture Fractures in Geothermal Resource Areas Using A Three-Component Long-Offset Surface Seismic Survey, PSInSAR, and Kinematic Analysis  

Broader source: Energy.gov [DOE]

Fining Large Aperture Fractures in Geothermal Resource Areas Using A Three-Component Long-Offset Surface Seismic Survey, PSInSAR, and Kinematic Analysis presentation at the April 2013 peer review meeting held in Denver, Colorado.

5

LARGE-APERTURE D- ACCELERATORS  

E-Print Network [OSTI]

Vignetted current profile at accelerator entrance aperture 'LARGE-APERTURE D" ACCELERATORS* 0. A. Anderson" " Lawrencen i a 9-1720 Abstract Accelerator designs are described for

Anderson, O.A.

2010-01-01T23:59:59.000Z

6

Fracture aperture reconstruction and determination of hydrological properties: a  

E-Print Network [OSTI]

Fracture aperture reconstruction and determination of hydrological properties: a case study for fracture aperture reconstruction. The rst one is a correlation technique that estimates the normal aper techniques are applied to discontinuities extracted from a core drilled down to 20 m in a fractured marl

Toussaint, Renaud

7

Large aperture diffractive space telescope  

DOE Patents [OSTI]

A large (10's of meters) aperture space telescope including two separate spacecraft--an optical primary objective lens functioning as a magnifying glass and an optical secondary functioning as an eyepiece. The spacecraft are spaced up to several kilometers apart with the eyepiece directly behind the magnifying glass "aiming" at an intended target with their relative orientation determining the optical axis of the telescope and hence the targets being observed. The objective lens includes a very large-aperture, very-thin-membrane, diffractive lens, e.g., a Fresnel lens, which intercepts incoming light over its full aperture and focuses it towards the eyepiece. The eyepiece has a much smaller, meter-scale aperture and is designed to move along the focal surface of the objective lens, gathering up the incoming light and converting it to high quality images. The positions of the two space craft are controlled both to maintain a good optical focus and to point at desired targets which may be either earth bound or celestial.

Hyde, Roderick A. (Livermore, CA)

2001-01-01T23:59:59.000Z

8

The investigation of fracture aperture effect on shale gas transport using discrete fracture model  

Science Journals Connector (OSTI)

Abstract Discrete fracture model (DFM) numerical simulation is used to investigate the shale gas transports in fractured porous media in this paper. A new seepage flow mathematic model, in which flow in fracture meets “Cubic law” and matrix meets “non-Darcy law”, is adopted and fracture aperture effect on the transport behavior is simulated by solving the nonlinear partial differential equations using finite element analysis (FEA). In this DFM, fluid flows into wellbore which is surrounded by impermeable rock matrix is merely through fractures that connect to it. The model is used to simulate a random generated fractures network to study the flow and transport characteristics in fractured porous media (FPM). Several cases with different fracture aperture in same natural fractured model are given. The preliminary simulation results show that both the natural and hydraulic fracture aperture have a significant impact on shale gas migration and production.

Lidong Mi; Hanqiao Jiang; Junjian Li; Tao Li; Ye Tian

2014-01-01T23:59:59.000Z

9

Project Profile: Improved Large Aperture Collector Manufacturing  

Broader source: Energy.gov [DOE]

Abengoa Solar, under the Solar Manufacturing Technology (SolarMat) program, will be investigating the use of an automotive-style high-rate fabrication and automated assembly techniques to achieve a substantial reduction in the deployment cost of their new SpaceTube advanced large aperture parabolic trough collector.

10

Large Aperture Electrostatic Dust Detector  

SciTech Connect (OSTI)

Diagnosis and management of dust inventories generated in next-step magnetic fusion devices is necessary for their safe operation. A novel electrostatic dust detector, based on a fine grid of interlocking circuit traces biased to 30 or 50 ? has been developed for the detection of dust particles on remote surfaces in air and vacuum environments. Impinging dust particles create a temporary short circuit and the resulting current pulse is recorded by counting electronics. Up to 90% of the particles are ejected from the grid or vaporized suggesting the device may be useful for controlling dust inventories. We report measurements of the sensitivity of a large area (5x5 cm) detector to microgram quantities of dust particles and review its applications to contemporary tokamaks and ITER.

C.H. Skinner, R. Hensley, and A.L Roquemore

2007-10-09T23:59:59.000Z

11

Constraints on flow regimes in wide-aperture fractures  

SciTech Connect (OSTI)

In recent years, significant advances have been made in our understanding of the complex flow processes in individual fractures, aided by flow visualization experiments and conceptual modeling efforts. These advances have led to the recognition of several flow regimes in individual fractures subjected to different initial and boundary conditions. Of these, the most important regimes are film flow, rivulet flow, and sliding of droplets. The existence of such significantly dissimilar flow regimes has been a major hindrance in the development of self-consistent conceptual models of flow for single fractures that encompass all the flow regimes. The objective of this study is to delineate the existence of the different flow regimes in individual fractures. For steady-state flow conditions, we developed physical constraints on the different flow regimes that satisfy minimum energy configurations, which enabled us to segregate the wide range of fracture transmissivity (volumetric flow rate per fracture width) into several flow regimes. These are, in increasing order of flow rate, flow of adsorbed films, flow of sliding drops, rivulet flow, stable film flow, and unstable (turbulent) film flow. The scope of this study is limited to wide-aperture fractures with the flow on the opposing sides of fracture being independent.

Ghezzehei, Teamrat A.

2004-02-28T23:59:59.000Z

12

High-resolution fracture aperture mapping using optical profilometry Pasha Ameli,1  

E-Print Network [OSTI]

High-resolution fracture aperture mapping using optical profilometry Pasha Ameli,1 Jean E. Elkhoury] Fractures play an important role in the Earth's crust, often controlling both mechanical and transport of fracture surfaces and the contacts and void spaces between fracture surfaces at high spatial resolution (10

Elkhoury, Jean

13

TECHNOLOGY DEVELOPMENT PROJECT PLAN Advanced Technology Large Aperture Space Telescope  

E-Print Network [OSTI]

(ATLAST) A Roadmap for UVIOR Technology, 2010-2020 24 April, 2009 T. Tupper Hyde, ATLAST TechnologistTECHNOLOGY DEVELOPMENT PROJECT PLAN for the Advanced Technology Large Aperture Space Telescope, and Ronald Polidan. #12;Advanced Technology Large-Aperture Space Telescope (ATLAST) 22 TABLE OF CONTENTS 1

Sirianni, Marco

14

Large-Aperture Segmented Mirror Telescope Design Concept  

E-Print Network [OSTI]

(ATLAS) Telescope: A Technology Roadmap for the Next Decade Principal Investigator: Dr. Marc Postman .............................................................................................13 5 Technology Roadmap................................................................109 #12;Advanced Technology Large-Aperture Space Telescope: A Technology Roadmap for the Next Decade 2

Sirianni, Marco

15

Measurement of fracture aperture fields using transmitted light: An evaluation of measurement errors and their influence on  

E-Print Network [OSTI]

Measurement of fracture aperture fields using transmitted light: An evaluation of measurement errors and their influence on simulations of flow and transport through a single fracture Russell L in fractures can be greatly enhanced through experimentation in transparent systems (analogs or replicas) where

Detwiler, Russell

16

The Balloon-borne Large Aperture Sub-millimetre Telescope  

E-Print Network [OSTI]

The Balloon-borne Large-Aperture Sub-millimetre Telescope (BLAST) will operate on a Long Duration Balloon platform with large format bolometer arrays at 250, 350 and 500 microns, initially using a 2m mirror, with plans to increase to 2.5m. BLAST is a collaboration between scientists in the USA, Canada, UK, Italy and Mexico. Funding has been approved and it is now in its building phase. The test flight is scheduled for 2002, with the first long duration flight the following year. The scientific goals are to learn about the nature of distant extragalactic star forming galaxies and cold pre-stellar sources by making deep maps both at high and low galactic latitudes. BLAST will be useful for planning Herschel key projects which use SPIRE.

Douglas Scott; the BLAST Team

2001-04-03T23:59:59.000Z

17

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

SciTech Connect (OSTI)

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.

Detwiler, Russell

2014-04-30T23:59:59.000Z

18

Design considerations for a large aperture high field superconducting dipole  

SciTech Connect (OSTI)

The final phase of the Fermilab upgrade proposal calls for a new ring of superconducting magnets to be placed in the existing Main Accelerator tunnel. The goal of this design study is to specify a high field dipole (HFD) that is capable of supporting fixed target operation (ramping, resonant extraction) at a field of 6.6T (1.5 Tev) and colliding beam physics at 8.0T (1.8 Tev). The magnetic field quality at high field is set by the large amplitude orbits associated with resonant extraction. The field quality must therefore be at least as good as the existing Tevatron magnets which fulfill these criteria. The high fields and large aperture of this magnet result in large forces on the coil and collar assemblies. Therefore, the cold mass design must be able to sustain these forces while providing sufficient cooling to the coils during 4.2 K fixed target operation, and a minimum heat load during 1.8 K collider operation. The design work is still in progress but a cosine-theta, cold-iron dipole with a 70mm inner diameter coil has been tentatively adopted. This report presents details on the conductor and cable parameters, coil cross-section, projected manufacturing tolerances, iron yoke design, and cold mass assembly. 4 refs., 5 figs., 1 tab.

Harfoush, F.; Ankenbrandt, C.; Harrison, M.; Kerby, J.; Koepke, K.; Mantsch, P.; Nicol, T.; Riddiford, A.; Theilacker, J.

1989-03-01T23:59:59.000Z

19

E-Print Network 3.0 - advanced technology large-aperture Sample...  

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

(Advanced Photonix). These diodes were chosen for two reasons. First... pulsed terahertz emitter, a large-aperture GaAs photoconductive switch, is carried out. It is...

20

Immiscible displacements in rough-walled fractures: Competition between roughening by random aperture variations and smoothing by in-plane curvature  

E-Print Network [OSTI]

Immiscible displacements in rough-walled fractures: Competition between roughening by random-walled fractures is controlled by the competition between random aperture variability which tends to roughen parameters: one that controls roughening the coefficient of variation of the aperture field, and another

Detwiler, Russell

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


21

The Balloon-borne Large Aperture Submillimeter Telescope: BLAST  

Science Journals Connector (OSTI)

The Balloon-borne Large Aperture Submillimeter Telescope (BLAST) is a suborbital surveying experiment designed to study the evolutionary history and processes of star formation in local galaxies (including the Milky Way) and galaxies at cosmological distances. The BLAST continuum camera, which consists of 270 detectors distributed between three arrays, observes simultaneously in broadband (30%) spectral windows at 250, 350, and 500 ?m. The optical design is based on a 2 m diameter telescope, providing a diffraction-limited resolution of 30 -->'' at 250 ?m. The gondola pointing system enables raster mapping of arbitrary geometry, with a repeatable positional accuracy of ~30 -->''; postflight pointing reconstruction to 5 -->'' rms is achieved. The onboard telescope control software permits autonomous execution of a preselected set of maps, with the option of manual override. In this paper we describe the primary characteristics and measured in-flight performance of BLAST. BLAST performed a test flight in 2003 and has since made two scientifically productive long-duration balloon flights: a 100 hr flight from ESRANGE (Kiruna), Sweden to Victoria Island, northern Canada in 2005 June; and a 250 hr, circumpolar flight from McMurdo Station, Antarctica, in 2006 December.

E. Pascale; P. A. R. Ade; J. J. Bock; E. L. Chapin; J. Chung; M. J. Devlin; S Dicker; M. Griffin; J. O. Gundersen; M. Halpern; P. C. Hargrave; D. H. Hughes; J. Klein; C. J. MacTavish; G. Marsden; P. G. Martin; T. G. Martin; P. Mauskopf; C. B. Netterfield; L. Olmi; G. Patanchon; M. Rex; D. Scott; C. Semisch; N. Thomas; M. D. P. Truch; C. Tucker; G. S. Tucker; M. P. Viero; D. V. Wiebe

2008-01-01T23:59:59.000Z

22

Effective Aperture of a Large Pseudorandom Low-Frequency  

E-Print Network [OSTI]

(LWA) LWA Station State of New Mexico, USA Aperture synthesis radio telescope · About 50 "stations" across New Mexico · Each station is an array of many elements · 20 - 80 MHz (at least) Project Status 16.6562 for Realistic = 3.0 in E-Plane = 0.5 in H-Plane [m2] Crude Estimate for Single Stand #12;8 Effective Aperture

Ellingson, Steven W.

23

Multiphase Flow in Complex Fracture Apertures Under a Wide Range of Flow Conditions  

SciTech Connect (OSTI)

The summary below is an update of our previous progress report of June, 2003. That previous progress report, which was submitted as a PDF document, is not recorded on the RIMS website but will appear on the EMSP website. Our recent results are in the following areas: (1) Single-component flow through a rough-walled fracture to validate our methods, we have simulated slow single-component fluid flow through a geometry taken from analogous laboratory experiments. The permeability of this fracture is studied as the direction of the driving force is changed. We find that the lattice-Boltzmann method agrees with the experimental data and with previous numerical efforts. Additionally, flow enhancement compared to the well-known cubic law is observed in certain directions, i.e., the direction in which channels are most strongly correlated. Conversely, flow inhibition is observed in the perpendicular direction. Fluid flow appears to follow the correlated channels. We are currently extending these studies to higher Reynolds numbers where classical approximations based on assumptions of slow creeping flow are no longer valid. (2) Capillary rise in simple and complex geometries Capillary rise is studied using the lattice-Boltzmann method. The geometries used are a circular tube, a rectangular tube, and a fracture between two rough walls. The capillary rise height and the shape of the interface is studied as a function of the size of the tube, the wetting tendency of the walls, the surface tension, and the magnitude of an applied body force. In performing this study we discovered a technical problem with the lattice-Boltzmann method: it exhibited lattice pinning. This pinning created two significant problems: the entrapment of small bubbles and a history dependence of the contact angle. We solved these problems by modifying our algorithm so that it now allows interfaces to move at a smaller velocity. The new method practically removes all effects of lattice pinning. For the case of rectangular tubes, we have shown that the shape of the interface follows theoretical predictions and that the pressure drop across the interface obeys Laplace's law. Consequently our improved method solves a significant problem encountered in lattice-Boltzmann simulations of drainage and imbibition. We are presently pursuing analogous studies in more complex geometries. (3) Macroscopic laws for two-component fluid flow through rough fractures. Macroscopic two-phase flow through porous media is commonly approximated by a generalization of Darcy's law, wherein ''relative permeability's'' represent the mobility of wetting and non-wetting fluids. We have recently begun studying the applicability of this approximation for two-phase flow through rough-walled fractures. We find that when the nonwetting fluid is unconnected it can become trapped in tight geometries. Once forcing exceeds a certain capillary threshold the non-wetting fluid starts to move again. This capillary threshold depends on the roughness of the fracture surface and the size of the fracture aperture. Further simulations are being performed to better specify these dependencies along with the relationship of relative permeability to fracture roughness. (4) Multiple relaxation-time lattice-Boltzmann method. We are exploring ways to use the lattice-Boltzmann method in a rectangular lattice with different spacing in one direction. This idea is motivated by the fact that self-affine fracture surfaces exhibit different scaling perpendicular to the plane of the fracture than they exhibit in the plane. Therefore, allowing different lattice spacing in the different directions should greatly increase the efficiency of our simulations. We also seek a practical way of solving a well-known problem that derives from using the ''bounce-back'' method to approximate no-slip boundary conditions. We are pursuing a new generalization of the ''multiple relaxation time generalized lattice-Boltzmann method'' and are in the process of implementing it. (5) Study of thermal fluctuations of fluid-fluid interfaces. We hav

Rothman, Daniel H.

2003-06-01T23:59:59.000Z

24

The Balloon-borne Large Aperture Submillimeter Telescope and Its Rebirth as a Polarimeter.  

E-Print Network [OSTI]

??The Balloon-borne Large Aperture Submillimeter Telescope (BLAST) is a 1.8 meter Cassegrain telescope that operates in three bands (250, 350, and 500 ?m), each with… (more)

Thomas, Nicholas E

2011-01-01T23:59:59.000Z

25

Hydraulic transmissivity and heat exchange efficiency of open fractures: a model based on lowpass filtered apertures  

E-Print Network [OSTI]

Natural open joints in rocks commonly present multi-scale self-affine apertures. This geometrical complexity affects fluid transport and heat exchange between the flow- ing fluid and the surrounding rock. In particular, long range correlations of self-affine apertures induce strong channeling of the flow which influences both mass and heat advection. A key question is to find a geometrical model of the complex aperture that describes at best the macroscopic properties (hydraulic conductivity, heat exchange) with the smallest number of parameters. Solving numerically the Stokes and heat equa- tions with a lubrication approximation, we show that a low pass filtering of the aperture geometry provides efficient estimates of the effective hydraulic and thermal properties (apertures). A detailed study of the influence of the bandwidth of the lowpass filtering on these transport properties is also performed. For instance, keeping the information of amplitude only of the largest Fourier length scales allows us to rea...

Neuville, Amélie; Schmittbuhl, Jean; 10.1111/j.1365-246X.2011.05126.x

2011-01-01T23:59:59.000Z

26

THE USE OF LARGE APERTURE ACCELERATING TUBES AT HIGH POTENTIAL GRADIENTS  

E-Print Network [OSTI]

observed in a mass analysis of the residual vacuum. Before removal of the accelerating tubes the mercury1507 THE USE OF LARGE APERTURE ACCELERATING TUBES AT HIGH POTENTIAL GRADIENTS J. H. BROADHURST John H. Williams Laboratory of Nuclear Physics, University of Minnesota, Minneapolis, Minnesota 55455, U

Paris-Sud XI, Université de

27

Low permeability gas reservoir production using large hydraulic fractures  

E-Print Network [OSTI]

LOVT PERMEABILITY GAS RESERVOIR PRODUCTION USING LARGE HYDRAULIC FRACTURES A Thesis by STEPHEN ALLEN HOLDITCH Approved as to style and content by: ( airman of Committee) (Head of Department) (Me er) (Member) (Membe r) (Member) (Member...) August 1970 111 ABSTRACT Low Permeability Gas Reservoir Production Using Large Hydraulic Fractures. (August 1970) Stephen Allen Holditch, B. S. , Texas ARM University Directed by: Dr, R. A. Morse There has been relatively little work published...

Holditch, Stephen A

2012-06-07T23:59:59.000Z

28

Advanced Technology Large-Aperture Space Telescope (ATLAST): A Technology Roadmap for the Next Decade  

E-Print Network [OSTI]

The Advanced Technology Large-Aperture Space Telescope (ATLAST) is a set of mission concepts for the next generation of UVOIR space observatory with a primary aperture diameter in the 8-m to 16-m range that will allow us to perform some of the most challenging observations to answer some of our most compelling questions, including "Is there life elsewhere in the Galaxy?" We have identified two different telescope architectures, but with similar optical designs, that span the range in viable technologies. The architectures are a telescope with a monolithic primary mirror and two variations of a telescope with a large segmented primary mirror. This approach provides us with several pathways to realizing the mission, which will be narrowed to one as our technology development progresses. The concepts invoke heritage from HST and JWST design, but also take significant departures from these designs to minimize complexity, mass, or both. Our report provides details on the mission concepts, shows the extraordinary s...

Postman, Marc

2009-01-01T23:59:59.000Z

29

Fracture-Flow-Enhanced Solute Diffusion into Fractured Rock  

E-Print Network [OSTI]

influence of effective fracture aperture, Water Resourcesa system of parallel fractures, Water Resources Research,solutions for a single fractures, Water Resources Research,

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

2008-01-01T23:59:59.000Z

30

An Experimental Investigation of Pressure-dependent and Time-dependent Fracture Aperture and Permeability in Barnett Shale.  

E-Print Network [OSTI]

?? U.S. domestic shale-gas production is economic owing to the new completion practice of horizontal wells and multiple hydraulic fractures. The performance of these fractures… (more)

Gong, Yin

2014-01-01T23:59:59.000Z

31

E-Print Network 3.0 - aperture imaging opportunities Sample Search...  

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

University Collection: Engineering ; Physics 2 PAPER 2004-230 Investigating Fracture Aperture Distributions Summary: . Keller14 imaged the fracture apertures using X-ray...

32

E-Print Network 3.0 - aperture flow imaging Sample Search Results  

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

Institute of Technology Collection: Engineering 3 PAPER 2004-230 Investigating Fracture Aperture Distributions Summary: to correction. ABSTRACT Fracture aperture is usually...

33

Abstract--We have recently completed a large-area, coded-aperture, gamma-ray imager for use in searching for radiation  

E-Print Network [OSTI]

Abstract-- We have recently completed a large-area, coded- aperture, gamma-ray imager for use. The in- strument uses a rank-19, one-dimensional coded aperture to cast shadow patterns onto a 0.57 m2 Na sufficient radiation can reach a large gamma-ray detec- tor from a small source to make detection possible

Horn, Berthold K.P.

34

LCLS X-ray mirror measurements using a large aperture visible light interferometer  

SciTech Connect (OSTI)

Synchrotron or FEL X-ray mirrors are required to deliver an X-ray beam from its source to an experiment location, without contributing significantly to wave front distortion. Accurate mirror figure measurements are required prior to installation to meet this intent. This paper describes how a 300 mm aperture phasing interferometer was calibrated to <1 nm absolute accuracy and used to mount and measure 450 mm long flats for the Linear Coherent Light Source (LCLS) at Stanford Linear Accelerator Center. Measuring focus mirrors with an interferometer requires additional calibration, because high fringe density introduces systematic errors from the interferometer's imaging optics. This paper describes how these errors can be measured and corrected. The calibration approaches described here apply equally well to interferometers larger than 300 mm aperture, which are becoming more common in optics laboratories. The objective of this effort was to install LCLS flats with < 10 nm of spherical curvature, and < 2 nm rms a-sphere. The objective was met by measuring the mirrors after fabrication, coating and mounting, using a 300 mm aperture phasing interferometer calibrated to an accuracy < 1 nm. The key to calibrating the interferometer accurately was to sample the error using independent geometries that are available. The results of those measurements helped identify and reduce calibration error sources. The approach used to measure flats applies equally well to focus mirrors, provided an additional calibration is performed to measure the error introduced by fringe density. This calibration has been performed on the 300 mm aperture interferometer, and the measurement correction was evaluated for a typical focus mirror. The 300 mm aperture limitation requires stitching figure measurements together for many X-ray mirrors of interest, introducing another possible error source. Stitching is eliminated by applying the calibrations described above to larger aperture instruments. The authors are presently extending this work to a 600 mm instrument. Instruments with 900 mm aperture are now becoming available, which would accommodate the largest mirrors of interest.

McCarville, T; Soufli, R; Pivovaroff, M

2011-03-02T23:59:59.000Z

35

Effective fracture geometry obtained with large water sand ratio  

E-Print Network [OSTI]

Shale gas formation exhibits some unusual reservoir characteristics: nano-darcy matrix permeability, presence of natural fractures and gas storage on the matrix surface that makes it unique in many ways. It’s difficult to design an optimum fracture...

Kumar, Amrendra

2009-05-15T23:59:59.000Z

36

Growth of geologic fractures into large-strain populations: review of nomenclature, subcritical crack growth, and some implications  

E-Print Network [OSTI]

Growth of geologic fractures into large-strain populations: review of nomenclature, subcritical at the earliest stages of fracture nucleation). Slow, subcritical crack growth in rock is associated

37

MULTI-PHASE FRACTURE-MATRIX INTERACTIONS UNDER STRESS CHANGES  

SciTech Connect (OSTI)

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

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

2005-06-15T23:59:59.000Z

38

Edit paper Methods for Large Scale Hydraulic Fracture Monitoring  

E-Print Network [OSTI]

In this paper we propose computationally efficient and robust methods for estimating the moment tensor and location of micro-seismic event(s) for large search volumes. Our contribution is two-fold. First, we propose a novel joint-complexity measure, namely the sum of nuclear norms which while imposing sparsity on the number of fractures (locations) over a large spatial volume, also captures the rank-1 nature of the induced wavefield pattern. This wavefield pattern is modeled as the outer-product of the source signature with the amplitude pattern across the receivers from a seismic source. A rank-1 factorization of the estimated wavefield pattern at each location can therefore be used to estimate the seismic moment tensor using the knowledge of the array geometry. In contrast to existing work this approach allows us to drop any other assumption on the source signature. Second, we exploit the recently proposed first-order incremental projection algorithms for a fast and efficient implementation of the resulting...

Ely, Gregory

2013-01-01T23:59:59.000Z

39

High energy second-harmonic generation of Nd:glass laser radiation with large aperture CsLiB6O10 crystals  

Science Journals Connector (OSTI)

We have demonstrated the generation of a high-energy green laser pulse using large aperture CsLiB6O10 (CLBO) crystals for the first time to our knowledge. A pulsed energy of 25 J at...

Kiriyama, Hiromitsu; Inoue, Norihiro; Yamakawa, Koichi

2002-01-01T23:59:59.000Z

40

Developing Magnetorheological Finishing (MRF) Technology for the Manufacture of Large-Aperture Optics in Megajoule Class Laser Systems  

SciTech Connect (OSTI)

Over the last eight years we have been developing advanced MRF tools and techniques to manufacture meter-scale optics for use in Megajoule class laser systems. These systems call for optics having unique characteristics that can complicate their fabrication using conventional polishing methods. First, exposure to the high-power nanosecond and sub-nanosecond pulsed laser environment in the infrared (>27 J/cm{sup 2} at 1053 nm), visible (>18 J/cm{sup 2} at 527 nm), and ultraviolet (>10 J/cm{sup 2} at 351 nm) demands ultra-precise control of optical figure and finish to avoid intensity modulation and scatter that can result in damage to the optics chain or system hardware. Second, the optics must be super-polished and virtually free of surface and subsurface flaws that can limit optic lifetime through laser-induced damage initiation and growth at the flaw sites, particularly at 351 nm. Lastly, ultra-precise optics for beam conditioning are required to control laser beam quality. These optics contain customized surface topographical structures that cannot be made using traditional fabrication processes. In this review, we will present the development and implementation of large-aperture MRF tools and techniques specifically designed to meet the demanding optical performance challenges required in large-aperture high-power laser systems. In particular, we will discuss the advances made by using MRF technology to expose and remove surface and subsurface flaws in optics during final polishing to yield optics with improve laser damage resistance, the novel application of MRF deterministic polishing to imprint complex topographical information and wavefront correction patterns onto optical surfaces, and our efforts to advance the technology to manufacture large-aperture damage resistant optics.

Menapace, J A

2010-10-27T23:59:59.000Z

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


41

Estimating the fracture density of small-scale vertical fractures when large-scale vertical fractures are present  

E-Print Network [OSTI]

When fractures are vertical, aligned and their dimensions are small relative to the seismic wavelength, the medium can be considered to be an equivalent Horizontal Transverse Isotropic (HTI) medium. However, geophysical ...

Liu, Yuwei

2013-01-01T23:59:59.000Z

42

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

E-Print Network [OSTI]

from previous evaluations of fracture hydromechanicalof flow through fractures in rock, In: Proceedings ofsaturated, variable-aperture fracture, Geophys. Res. Lett. ,

Cappa, F.

2009-01-01T23:59:59.000Z

43

Mode I fracture of a biopolymer gel: rate-dependent dissipation and large deformations disentangled  

E-Print Network [OSTI]

We have designed a new experimental setup able to investigate fracture of soft materials at small scales. At high crack velocity, where energy is mostly dissipated through viscoelastic processes, we observe an increasingly large high strain domain in the crack tip vicinity. Taking advantage of our ability to determine where linear elasticity breaks down, we derive a simple prediction for the evolution of the energy release rate with the crack velocity.

Maxime Lefranc; Elisabeth Bouchaud

2015-01-06T23:59:59.000Z

44

Fracture compliance estimation using borehole tube waves  

E-Print Network [OSTI]

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 ...

Bakku, Sudhish Kumar

45

Scales Depencence of Fracture Density and Fabric in the Damage Zone of a Large Displacement Continental Transform Fault  

E-Print Network [OSTI]

image (XPL) of the same thin section. .............................................................. 49 Figure 7. Linear transgranular fracture density variation relative to distance from the large mesoscale subsidiary fault (SF, blue line) located... at 3062.5 m MD shown in the wrap-around maps of the Phase 1 core (Figure 5). ...................... 50 Figure 8. Linear intragranular fracture density variation relative to distance from the large mesoscale subsidiary fault (SF, blue line) located...

Ayyildiz, Muhammed

2012-08-28T23:59:59.000Z

46

Multi-Phase Fracture-Matrix Interactions Under Stress Changes  

SciTech Connect (OSTI)

The main objectives of this project are to quantify the changes in fracture porosity and multi-phase transport properties as a function of confining stress. These changes will be integrated into conceptual and numerical models that will improve our ability to predict and optimize fluid transport in fractured system. This report details our progress on: (a) developing the direct experimental measurements of fracture aperture and topology and fluid occupancy using high-resolution x-ray micro-tomography, (b) counter-current fluid transport between the matrix and the fracture, (c) studying the effect of confining stress on the distribution of fracture aperture and two-phase flow, and (d) characterization of shear fractures and their impact on multi-phase flow. The three-dimensional surface that describes the large-scale structure of the fracture in the porous medium can be determined using x-ray micro-tomography with significant accuracy. Several fractures have been scanned and the fracture aperture maps have been extracted. The success of the mapping of fracture aperture was followed by measuring the occupancy of the fracture by two immiscible phases, water and decane, and water and kerosene. The distribution of fracture aperture depends on the effective confining stress, on the nature of the rock, and the type and distribution of the asperities that keep the fracture open. Fracture apertures at different confining stresses were obtained by micro-tomography covering a range of about two thousand psig. Initial analysis of the data shows a significant aperture closure with increase in effective confining stress. Visual and detailed descriptions of the process are shown in the report. Both extensional and shear fractures have been considered. A series of water imbibition tests were conducted in which water was injected into a fracture and its migration into the matrix was monitored with CT and DR x-ray techniques. The objective was to understand the impact of the fracture, its topology and occupancy on the nature of mass transfer between the matrix and the fracture. Counter-current imbibition next to the fracture was observed and quantified, including the influence of formation layering. A group of Shear fractures were studied, with layers perpendicular and parallel to the main axis of the sample. The structures of the fractures as well as their impact on absolute permeability and on oil displacement by water were evaluated. Shear fractures perpendicular to the layers lead to a wide distribution of pores and to an overall increase in absolute permeability. Shear fractures parallel to the layers lead to an overall increase in absolute permeability, but a decrease in displacement efficiency. This DoE project funded or partially funded three Ph.D. and four M.Sc. students at the Pennsylvania State University. The results from the research have yielded several abstracts, presentations and papers. Much of the work is still in the process of being published.

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

2005-12-07T23:59:59.000Z

47

Characteristics of the nuclear magnetic resonance logging response in fracture oil and gas reservoirs  

Science Journals Connector (OSTI)

Fracture oil and gas reservoirs exist in large numbers. The accurate logging evaluation of fracture reservoirs has puzzled petroleum geologists for a long time. Nuclear magnetic resonance (NMR) logging is an effective new technology for borehole measurement and formation evaluation. It has been widely applied in non-fracture reservoirs, and good results have been obtained. But its application in fracture reservoirs has rarely been reported in the literature. This paper studies systematically the impact of fracture parameters (width, number, angle, etc), the instrument parameter (antenna length) and the borehole condition (type of drilling fluid) on NMR logging by establishing the equation of the NMR logging response in fracture reservoirs. First, the relationship between the transverse relaxation time of fluid-saturated fracture and fracture aperture in the condition of different transverse surface relaxation rates was analyzed; then, the impact of the fracture aperture, dip angle, length of two kinds of antennas and mud type was calculated through forward modeling and inversion. The results show that the existence of fractures affects the NMR logging; the characteristics of the NMR logging response become more obvious with increasing fracture aperture and number of fractures. It is also found that T2 distribution from the fracture reservoir will be affected by echo spacing, type of drilling fluids and length of antennas. A long echo spacing is more sensitive to the type of drilling fluid. A short antenna is more effective for identifying fractures. In addition, the impact of fracture dip angle on NMR logging is affected by the antenna length.

Lizhi Xiao; Kui Li

2011-01-01T23:59:59.000Z

48

MULTI-PHASE FRACTURE-MATRIX INTERACTIONS UNDER STRESS CHANGES  

SciTech Connect (OSTI)

The main objectives of this project are to quantify the changes in fracture porosity and multiphase transport properties as a function of confining stress. These changes will be integrated into conceptual and numerical models that will improve our ability to predict and optimize fluid transport in fractured system. This report details our progress on: (1) developing the direct experimental measurements of fracture aperture and topology using high-resolution x-ray microtomography, (2) modeling of fracture permeability in the presence of asperities and confining stress, and (3) simulation of two-phase fluid flow in a fracture and a layered matrix. The three-dimensional surface that describes the large-scale structure of the fracture in the porous medium can be determined using x-ray micro-tomography with significant accuracy. The distribution of fracture aperture is a difficult issue that we are studying and developing methods of quantification. The difficulties are both numerical and conceptual. Numerically, the three-dimensional data sets include millions, and sometimes, billions of points, and pose a computational challenge. The conceptual difficulties derive from the rough nature of the fracture surfaces, and the heterogeneous nature of the rock matrix. However, the high-resolution obtained by the imaging system provides us a much needed measuring environment on rock samples that are subjected to simultaneous fluid flow and confining stress. Pilot multi-phase experiments have been performed, proving the ability to detect two phases in certain large fractures. The absolute permeability of a fracture depends on the behavior of the asperities that keep it open. A model is being developed that predicts the permeability and average aperture of a fracture as a function of time under steady flow of water including the pressure solution at the asperity contact points. Several two-phase flow experiments in the presence of a fracture tip were performed in the past. At the present time, we are developing an inverse process using a simulation model to understand the fluid flow patterns in the presence of a fracture, and the interactions between fluid flow in the fracture and the adjacent matrix. Preliminary results demonstrate that the flow patterns are significantly impacted by the presence of the fracture. Bypassing is quantified and we expect to be able to extract from the modeling the distribution of properties in the fracture and the adjacent matrix.

A.S. Grader; D. Elsworth; P.M. Halleck; F. Alvarado; H. Yasuhara; A. Alajmi; Z. Karpyn

2002-10-28T23:59:59.000Z

49

Solar Central Receiver with an Irising Aperture  

E-Print Network [OSTI]

. If the aperture is small, it will be inefficient for periods when the solar isolation is inclined due to spillage. However, if the aperture is large, it will be inefficient for periods when the solar isolation is normal, due to excess heat radiation and convection...

Galal, T.; Kulaib, A. M.; Abuzaid, M.

2010-01-01T23:59:59.000Z

50

Rotating Aperture System  

DOE Patents [OSTI]

A rotating aperture system includes a low-pressure vacuum pumping stage with apertures for passage of a deuterium beam. A stator assembly includes holes for passage of the beam. The rotor assembly includes a shaft connected to a deuterium gas cell or a crossflow venturi that has a single aperture on each side that together align with holes every rotation. The rotating apertures are synchronized with the firing of the deuterium beam such that the beam fires through a clear aperture and passes into the Xe gas beam stop. Portions of the rotor are lapped into the stator to improve the sealing surfaces, to prevent rapid escape of the deuterium gas from the gas cell.

Rusnak, Brian (Livermore, CA); Hall, James M. (Livermore, CA); Shen, Stewart (Danville, CA); Wood, Richard L. (Santa Fe, NM)

2005-01-18T23:59:59.000Z

51

Scale-Dependent Fracture-Matrix Interactions And Their Impact on Radionuclide Transport - Final Report  

SciTech Connect (OSTI)

Matrix diffusion and adsorption within a rock matrix are widely regarded as important mechanisms for retarding the transport of radionuclides and other solutes in fractured rock (e.g., Neretnieks, 1980; Tang et al., 1981; Maloszewski and Zuber, 1985; Novakowski and Lapcevic, 1994; Jardine et al., 1999; Zhou and Xie, 2003; Reimus et al., 2003a,b). When remediation options are being evaluated for old sources of contamination, where a large fraction of contaminants reside within the rock matrix, slow diffusion out of the matrix greatly increases the difficulty and timeframe of remediation. Estimating the rates of solute exchange between fractures and the adjacent rock matrix is a critical factor in quantifying immobilization and/or remobilization of DOE-relevant contaminants within the subsurface. In principle, the most rigorous approach to modeling solute transport with fracture-matrix interaction would be based on local-scale coupled advection-diffusion/dispersion equations for the rock matrix and in discrete fractures that comprise the fracture network (Discrete Fracture Network and Matrix approach, hereinafter referred to as DFNM approach), fully resolving aperture variability in fractures and matrix property heterogeneity. However, such approaches are computationally demanding, and thus, many predictive models rely upon simplified models. These models typically idealize fracture rock masses as a single fracture or system of parallel fractures interacting with slabs of porous matrix or as a mobile-immobile or multi-rate mass transfer system. These idealizations provide tractable approaches for interpreting tracer tests and predicting contaminant mobility, but rely upon a fitted effective matrix diffusivity or mass-transfer coefficients. However, because these fitted parameters are based upon simplified conceptual models, their effectiveness at predicting long-term transport processes remains uncertain. Evidence of scale dependence of effective matrix diffusion coefficients obtained from tracer tests highlights this point and suggests that the underlying mechanisms and relationship between rock and fracture properties are not fully understood in large complex fracture networks. In this project, we developed a high-resolution DFN model of solute transport in fracture networks to explore and quantify the mechanisms that control transport in complex fracture networks and how these may give rise to observed scale-dependent matrix diffusion coefficients. Results demonstrate that small scale heterogeneity in the flow field caused by local aperture variability within individual fractures can lead to long-tailed breakthrough curves indicative of matrix diffusion, even in the absence of interactions with the fracture matrix. Furthermore, the temporal and spatial scale dependence of these processes highlights the inability of short-term tracer tests to estimate transport parameters that will control long-term fate and transport of contaminants in fractured aquifers.

Detwiler, Russell

2014-06-30T23:59:59.000Z

52

Large-Scale Fluid-Structure Interaction Simulation of Viscoplastic and Fracturing  

E-Print Network [OSTI]

of large plastic deformations and rupture of thin alu- minum tubes due to the passage of ethylene-oxygen detonations. 1 Introduction The Center for Simulation of Dynamic Response of Materials at the California In with such a "weakly coupled" method, when the evolving interface geometry and velocities are imposed as boundary

Deiterding, Ralf

53

Constraint effects within R6 framework: Validation by small and large scale fracture test results for A533B-1 steel  

SciTech Connect (OSTI)

A framework for including constraint effects in the failure assessment diagram approach for fracture assessment was described in the 1994 ASME PVP conference. Constraint effects were treated by modifying the shape of the failure assessment curve. In their simplest form, the modifications involve only two parameters: one quantifying the magnitude of structural constraint which depends on geometry, crack size and loading; and the second quantifying the influence of constraint on fracture toughness. The validity of the framework is investigated in this paper by considering the results and associated analysis of both small and large scale upper shelf fracture toughness tests performed on an A533B-1 steel plate. The specimens had a range of crack-tip constraint conditions. The results demonstrated that: (i) Crack-tip constraint significantly influences the ductile fracture characteristics of this material, (ii) this influence is well quantified by the elastic T-stress or elastic-plastic Q-stress, and (iii) the modified R6 framework provides conservative assessments of fracture initiation.

Sherry, A.H.; Sharples, J.K.; Sanderson, D.J.; Gardner, L. [AEA Technology, Risley (United Kingdom). Technical Services Division; Ainsworth, R.A. [Nuclear Electric plc, Berkeley (United Kingdom)

1995-11-01T23:59:59.000Z

54

Multi-scale approach to invasion percolation of rock fracture networks  

E-Print Network [OSTI]

A multi-scale scheme for the invasion percolation of rock fracture networks with heterogeneous fracture aperture fields is proposed. Inside fractures, fluid transport is calculated on the finest scale and found to be localized in channels as a consequence of the aperture field. The channel network is characterized and reduced to a vectorized artificial channel network (ACN). Different realizations of ACNs are used to systematically calculate efficient apertures for fluid transport inside differently sized fractures as well as fracture intersection and entry properties. Typical situations in fracture networks are parameterized by fracture inclination, flow path length along the fracture and intersection lengths in the entrance and outlet zones of fractures. Using these scaling relations obtained from the finer scales, we simulate the invasion process of immiscible fluids into saturated discrete fracture networks, which were studied in previous works.

Ali N. Ebrahimi; Falk K. Wittel; Nuno A. M. Araújo; Hans J. Herrmann

2014-08-12T23:59:59.000Z

55

Multiphase Flow in Geometrically Simple Fracture Intersections  

SciTech Connect (OSTI)

A two-dimensional lattice Boltzmann (LB) model with fluid-fluid and solid-fluid interaction potentials was used to Study gravity-driven flow in geometrically simple fracture intersections. simulated scenarios included fluid dripping from a fracture aperture, two-phase flow through intersecting fractures and thin-filin flow oil smooth and undulating solid surfaces. Qualitative comparisons with recently published experimental findings indicate that for these scenarios the LB model captured the underlying physics reasonably well.

Hakan Basagaoglu; Paul Meakin; Sauro Succi; Timothy R. Ginn

2006-03-01T23:59:59.000Z

56

Multiphase flow in geometrically simple fracture intersection  

SciTech Connect (OSTI)

A two-dimensional lattice Boltzmann (LB) model with fluid-fluid and solid-fluid interaction potentials was used to study gravity-driven flow in geometrically simple fracture intersections. Simulated scenarios included fluid dripping from a fracture aperture, two-phse flow through intersecting fractures, and thin-film flow on smooth and undulating solid surfaces. Qualititative comparisons with recently published experimental findings indicate that for these scenarios the LB model captured the underlying physics reasonably well.

H. Basagaoglu; P. Meakin; M. Mathew

2006-03-01T23:59:59.000Z

57

Aperture center energy showcase  

SciTech Connect (OSTI)

Sandia and Forest City have established a Cooperative Research and Development Agreement (CRADA), and the partnership provides a unique opportunity to take technology research and development from demonstration to application in a sustainable community. A project under that CRADA, Aperture Center Energy Showcase, offers a means to develop exhibits and demonstrations that present feedback to community members, Sandia customers, and visitors. The technologies included in the showcase focus on renewable energy and its efficiency, and resilience. These technologies are generally scalable, and provide secure, efficient solutions to energy production, delivery, and usage. In addition to establishing an Energy Showcase, support offices and conference capabilities that facilitate research, collaboration, and demonstration were created. The Aperture Center project focuses on establishing a location that provides outreach, awareness, and demonstration of research findings, emerging technologies, and project developments to Sandia customers, visitors, and Mesa del Sol community members.

Torres, J. J.

2012-03-01T23:59:59.000Z

58

Synthetic Aperture Radar Movie Gallery -- Sandia National Laboratories  

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

Synthetic Aperture Radar Movie Gallery Synthetic Aperture Radar Movie Gallery This gallery features movies of Sandia National Laboratories' synthetic aperture radar imagery of Albuquerque, New Mexico and Washington, DC. Sandia's Twin-Otter SAR produced these high-resolution stripmap images in real time. (Note: The movies below have been downsampled greatly to make them suitable for viewing on the world wide web. These movies are not recommended for modems of speeds less than 56 kbps due to their large file sizes.) Albuquerque, NM Area Movies Sandia National Laboratories' Twin-Otter SAR produced these Ku-Band 0.3 and 1.0 meter resolution images of Albuquerque, NM in real time. Synthetic aperture radar movie of west Gibson Blvd 0.3 meter airborne synthetic aperture radar movie from I-25 to Maxwell along Gibson Blvd. (Length: 30 seconds)

59

Modeling the thermal-hydrologic processes in a large-scale underground heater test in partially saturated fractured tuff  

SciTech Connect (OSTI)

The Drift Scale Test (DST) is being conducted in an underground facility at Yucca Mountain, Nevada, to probe the coupled thermal, hydrological, mechanical, and chemical processes likely to occur in the fractured rock mass around a potential high-level nuclear waste repository. Thermal-hydrological processes in the DST have been simulated using a three-dimensional numerical model. The model incorporates the realistic test configuration and all available site-specific measurements pertaining to the thermal and hydrological properties of the unsaturated fractured tuff of the test block. The modeled predictions were compared to the extensive set of measured data collected in the first year of this 8-year-long test. The mean error between the predictions and measurement at 12 months of heating for over 1600 temperature sensors is about 2 degrees C. Heat-pipe signature in the temperature data, indicating two-phase regions of liquid-vapor counterflow, is seen in both the measurements and simulated results. The redistribution of moisture content in the rock mass (resulting from vaporization and condensation) was probed by periodic air-injection testing and geophysical measurements. Good agreement also occurred between the model predictions and these measurements. The general agreement between predictions from the numerical simulations and the measurements of the thermal test indicates that our fundamental understanding of the coupled thermal-hydrologic processes at Yucca Mountain is sound. However, effects of spatial heterogeneity from discrete fractures that are observed in the temperature data are not matched by simulations from the numerical model, which treat the densely spaced fractures as a continuum.

Birkholzer, J.T.; Tsang, Y.W.

1999-06-24T23:59:59.000Z

60

Fracture Blisters  

E-Print Network [OSTI]

21. McCann S, Gruen G. Fracture Blisters: A Review of thewith Lower Extremity Fracture: Results of a ProspectiveC, Koval K. Treatment of Fracture Blisters: A Prospective

Uebbing, Claire M; Walsh, Mark; Miller, Joseph B; Abraham, Mathew; Arnold, Clifford

2011-01-01T23:59:59.000Z

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


61

The effect of synchrobetatron coupling on the dynamic aperture  

SciTech Connect (OSTI)

The effect of synchrobetatron coupling on the dynamic aperture was studied by comparing the dynamic aperture for a particle with a large fixed {Delta}p/p, no synchrotron oscillations present, with the dynamic aperture for a particle, with a synchrotron oscillation amplitude, of the same {Delta}p/p. The particle with the synchrotron oscillation present was found to have a smaller dynamic aperture than the particle with the fixed {Delta}p/p. It is suggested that this reduction in dynamic aperture may be due to non-linear coupling between the longitudinal and transverse motions. For RHIC, whose lattice and rf were used in this study, the longitudinal phase space is much larger than the transverse phase space, by a factor of several thousand, and a small amount of coupling can cause considerable growth in the transverse motion. The effect is most pronounced at lower energies in RHIC, where larger momentum spread and transverse amplitudes are required. At {gamma} = 30 in RHIC, with a synchrotron oscillation amplitude of {Delta}p/p = 0.005, the dynamic aperture is reduced by about 6 mm by the presence of the synchrotron oscillations. The effect may be more important for RHIC than for other superconducting proton colliders, because of its relatively low energy and because of the importance of intrabeam scattering for heavy ions. This results in larger dynamic aperture requirements for RHIC both in transverse space and in momentum spread.

Parzen, G.

1992-12-31T23:59:59.000Z

62

The effect of synchrobetatron coupling on the dynamic aperture  

SciTech Connect (OSTI)

The effect of synchrobetatron coupling on the dynamic aperture was studied by comparing the dynamic aperture for a particle with a large fixed {Delta}p/p, no synchrotron oscillations present, with the dynamic aperture for a particle with a synchrotron oscillation amplitude of the same {Delta}p/p. The particle with the synchrotron oscillation present was found to have a smaller dynamic aperture than that of the particle with the fixed {Delta}p/p. It is suggested that this reduction in dynamic aperture may be due to a non-linear coupling between the longitudinal and transverse motions. For RHIC, whose lattice and RF were used in this study, the longitudinal phase space is much larger than the transverse phase space by a factor of several thousand, and a small amount of coupling can cause considerable growth in the transverse motion. The effect is most pronounced at lower energies in RHIC, where larger momentum spread and transverse amplitudes are required. At {gamma} = 30 in RHIC, with a synchrotron oscillation amplitude of {Delta}p/p = 0.005, the dynamic aperture is reduced by about 6 mm by the presence of the synchrotron oscillations. The effect may be more important for RHIC than for other superconducting proton colliders, because of its relatively low energy and because of the importance of intrabeam scattering for heavy ions. This results in larger dynamic aperture requirements for RHIC both in transverse space and in momentum spread.

Parzen, G.

1993-03-01T23:59:59.000Z

63

The effect of synchrobetatron coupling on the dynamic aperture  

SciTech Connect (OSTI)

The effect of synchrobetatron coupling on the dynamic aperture was studied by comparing the dynamic aperture for a particle with a large fixed [Delta]p/p, no synchrotron oscillations present, with the dynamic aperture for a particle with a synchrotron oscillation amplitude of the same [Delta]p/p. The particle with the synchrotron oscillation present was found to have a smaller dynamic aperture than that of the particle with the fixed [Delta]p/p. It is suggested that this reduction in dynamic aperture may be due to a non-linear coupling between the longitudinal and transverse motions. For RHIC, whose lattice and RF were used in this study, the longitudinal phase space is much larger than the transverse phase space by a factor of several thousand, and a small amount of coupling can cause considerable growth in the transverse motion. The effect is most pronounced at lower energies in RHIC, where larger momentum spread and transverse amplitudes are required. At [gamma] = 30 in RHIC, with a synchrotron oscillation amplitude of [Delta]p/p = 0.005, the dynamic aperture is reduced by about 6 mm by the presence of the synchrotron oscillations. The effect may be more important for RHIC than for other superconducting proton colliders, because of its relatively low energy and because of the importance of intrabeam scattering for heavy ions. This results in larger dynamic aperture requirements for RHIC both in transverse space and in momentum spread.

Parzen, G.

1993-03-01T23:59:59.000Z

64

Pore-scale simulation of coupled reactive transport and dissolution in fractures and porous media using the level set interface tracking method  

SciTech Connect (OSTI)

A level set simulation methodology developed for modeling coupled reactive transport and structure evolution has been applied to dissolution in fracture apertures and porous media. The coupled processes such as fluid flow, reactant transport and dissolution at the solid-liquid interfaces are handled simultaneously. The reaction-induced evolution of solid-liquid interfaces is captured using the level set method, with the advantage of representing the interface with sub-grid scale resolution. The coupled processes are simulated for several geometric models of fractures and porous media under various flow conditions and reaction rates. Quantitative relationships between permeability and porosity are obtained from some of the simulation results and compared with analytical constitutive relations (i.e., the conventional cubic law and the Carman-Kozeny law) based on simplified pore space geometries and reaction induced geometric evolutions. The drastic deviation of the simulation results from these analytical theories is explained by the development of large local concentration gradients of reactants within fracture apertures and individual pores observed in the simulation results and consequently the complex geometric evolution patterns of fracture apertures and pores due to mineral dissolution. The simulation results support the argument that traditional constitutive relations based on simplified geometries and conditions have limited applicability in predicting field scale reactive transport and that incorporation of micro-scale physics is necessary.

Hai Huang; Xiaoyi Li

2011-01-01T23:59:59.000Z

65

Dipole aperture and superconductor requirements  

SciTech Connect (OSTI)

The cost of an accelerator is not proportional to the aperture. A change in aperture by a certain percentage results in an overall accelerator cost change by only a fraction of that percentage; the fraction may be between 0.1 and 0.5 and is almost independent of the bending field. This estimate is obtained by analyzing the superconductor requirements as a function of aperture and by making rough estimates of the largest cost items of the accelerator such as magnets and ring tunnel.

Wipf, S.L.

1983-12-11T23:59:59.000Z

66

Scale-Dependent Fracture-Matrix Interactions and Their Impact on Radionuclide Transport: Development of efficient particle-tracking methods  

SciTech Connect (OSTI)

Matrix Diffusion and Adsorption within a rock matrix are important mechanisms for retarding transport of radionuclides in fractured rock. Due to computational limitations and difficulties in characterizing complex subsurface systems, diffusive exchange between a fracture network and surrounding rock matrix is often modeled using simplified conceptual representations. There is significant uncertainty in “effective” parameters used in these models, such as the “effective matrix diffusivity”. Often, these parameters are estimated by fitting sparse breakthrough data, and estimated values fall outside meaningful ranges, because simplified interpretive models do not consider complex three-dimensional flow. There is limited understanding of the relationship between the effective parameters and rock mass characteristics including network structure and matrix properties. There is also evidence for an apparent scale-dependence in “effective matrix diffusion” coefficients. These observations raise questions on whether fracture-matrix interaction parameters estimated from small-scale tracer tests can be used for predicting radionuclide fate and transport at the scale of DOE field sites. High-resolution three-dimensional Discrete-Fracture-Network-Matrix (DFNM) models based on well-defined local scale transport equations can help to address some of these questions. Due to tremendous advances in computational technology over the last 10 years, DFNM modeling in relatively large domains is now feasible. The overarching objective of our research is to use DFNM modeling to improve fundamental understanding of how effective parameters in conceptual models are related to fracture network structure and matrix properties. An advanced three-dimensional DFNM model is being developed, which combines upscaled particle-tracking algorithms for fracture-matrix interaction and a parallel fracture-network flow simulator. The particle-tracking algorithms allow complexity in flow fields at different scales, and track transport across fracture-matrix interfaces based on rigorous local approximations to the transport equations. This modeling approach can incorporate aperture variability, multi-scale preferential flow and matrix heterogeneity. We developed efficient particle-tracking methods for handling matrix diffusion and adsorption on fracture walls and demonstrated their efficiency for use within the context of large-scale complex fracture network models with variability in apertures across a network of fractures and within individual fractures.

Rajaram, Harihar [University of Colorado, Boulder; Brutz, Michael [University of Colorado, Boulder; Klein, Dylan R [University of Colorado, Boulder; Mallikamas, Wasin [University of Colorado, Boulder

2014-09-18T23:59:59.000Z

67

Simulation on Discrete Fracture Network Using Flexible Voronoi Gridding  

E-Print Network [OSTI]

........................................... 3 1.2.2 Gridding Techniques ............................................................. 4 1.2.2.1 Globally Orthogonal Grid ...................................... 5 1.2.2.2 Corner Point Grid... ................................................... 5 1.2.3 Locally Orthogonal Grid ....................................................... 6 1.3 Introduction to Discrete Fracture Network Simulation ................... 7 1.4 Introduction to Fracture Aperture Measurement Using X-Ray CT...

Syihab, Zuher

2011-02-22T23:59:59.000Z

68

Experimental study of turbulent unconfined groundwater flow in a single fracture  

E-Print Network [OSTI]

Experimental study of turbulent unconfined groundwater flow in a single fracture Jiazhong Qiana groundwater flow in a single fracture under the conditions of different surface roughness and apertures. We found that the gradient of the Reynolds number versus the average velocity in a single fracture

Zhan, Hongbin

69

Using seismic tomography to characterize fracture systems induced by hydraulic fracturing  

SciTech Connect (OSTI)

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

Fehler, M.; Rutledge, J.

1995-01-01T23:59:59.000Z

70

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

SciTech Connect (OSTI)

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.

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

2013-08-01T23:59:59.000Z

71

Light passing through subwavelength apertures  

Science Journals Connector (OSTI)

This review provides a perspective on the recent developments in the transmission of light through subwavelength apertures in metal films. The main focus is on the phenomenon of extraordinary optical transmission in periodic hole arrays, discovered over a decade ago. It is shown that surface electromagnetic modes play a key role in the emergence of the resonant transmission. These modes are also shown to be at the root of both the enhanced transmission and beaming of light found in single apertures surrounded by periodic corrugations. This review describes both the theoretical and experimental aspects of the subject. For clarity, the physical mechanisms operating in the different structures considered are analyzed within a common theoretical framework. Several applications based on the transmission properties of subwavelength apertures are also addressed.

F. J. Garcia-Vidal, L. Martin-Moreno, T. W. Ebbesen, and L. Kuipers

2010-03-12T23:59:59.000Z

72

On the Theory of Diffraction by an Aperture in an Infinite Plane Screen. I  

Science Journals Connector (OSTI)

The diffraction of a scalar plane wave by an aperture in an infinite plane screen is examined theoretically. The wave function at an arbitrary point in space is expressed in terms of its values in the aperture, and constructed so as to vanish on the screen, in accordance with the assumed boundary condition. An integral equation to determine the aperture field is obtained from the continuity requirement for the normal derivative of the wave function on traversing the plane of the aperture. Utilizing the integral equation (whose solution is generally unobtainable), the amplitude of the diffracted spherical wave at large distances from the aperture is exhibited in a form which is stationary with respect to small variations (relative to the correct values) of the aperture fields arising from a pair of incident waves. This expression is independent of the scale of the aperture fields. The transmission cross section of the aperture for a plane wave is found to be simply related to the diffracted amplitude observed in the direction of incidence. The variational formulation is applied in detail for a wave incident normally on a circular aperture. By comparison with the exact results available for this problem, it appears that the use of suitable trial aperture fields in the variational formulation yields approximate, yet accurate, expressions for the diffracted amplitude and transmission cross section over a wide range of frequencies.

Harold Levine and Julian Schwinger

1948-10-15T23:59:59.000Z

73

Fracturing pressures and near-well fracture geometry of arbitrarily oriented and horizontal wells  

SciTech Connect (OSTI)

The hydraulic fracturing of arbitrarily oriented and horizontal wells is made challenging by the far more complicated near-well fracture geometry compared to that of conventional vertical wells. This geometry is important both for hydraulic fracture propagation and the subsequent post-treatment well performance. Fracture tortuosity of arbitrarily oriented and horizontal wells is likely to cause large initiation pressures and reduction in the fracture widths. This paper presents a comprehensive study of the effects of important variables, including the principal stresses, wellbore orientation, and perforation configuration on fracture geometry. Initiation pressures, the contact between arbitrarily oriented wells and the fracture plane, and the near-well fracture geometry are determined and discussed. This study also shows that because of the near-well stress concentration the fracture width at the wellbore is always smaller than the maximum fracture width. This can have important consequences during hydraulic fracturing.

Chen, Z.; Economides, M.J.

1995-12-31T23:59:59.000Z

74

Analysis of the classical pseudo-3D model for hydraulic fracture with equilibrium height growth across stress barriers  

E-Print Network [OSTI]

Analysis of the classical pseudo-3D model for hydraulic fracture with equilibrium height growth t This paper deals with the so-called ``pseudo three-dimensional'' (P3D) model for a hydraulic fracture of the length, height, and aperture of the hydraulic fracture, in contrast to the numerical formulations adopted

Peirce, Anthony

75

Medical imaging with coded apertures  

SciTech Connect (OSTI)

Now algorithms were investigated for image reconstruction in emission tomography which could incorporate complex instrumental effects such as might be obtained with a coded aperture system. The investigation focused on possible uses of the wavelet transform to handle non-stationary instrumental effects and analytic continuation of the Radon transform to handle self-absorption. Neither investigation was completed during the funding period and whether such algorithms will be useful remains an open question.

Keto, E.; Libby, S.

1995-06-16T23:59:59.000Z

76

Hydraulic Fracturing (Vermont)  

Broader source: Energy.gov [DOE]

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

77

Analysis of Thermally Induced Changes in Fractured Rock Permeability during Eight Years of Heating and Cooling at the Yucca Mountain Drift Scale Test  

SciTech Connect (OSTI)

We analyzed a data set of thermally induced changes in fractured rock permeability during a four-year heating (up to 200 C) and subsequent four-year cooling of a large volume, partially saturated and highly fractured volcanic tuff at the Yucca Mountain Drift Scale Test, in Nevada, USA. Permeability estimates were derived from about 700 pneumatic (air-injection) tests, taken periodically at 44 packed-off borehole intervals during the heating and cooling cycle from November 1997 through November 2005. We analyzed air-permeability data by numerical modeling of thermally induced stress and moisture movements and their impact on air permeability within the highly fractured rock. Our analysis shows that changes in air permeability during the initial four-year heating period, which were limited to about one order of magnitude, were caused by the combined effects of thermal-mechanically-induced stress on fracture aperture and thermal-hydrologically-induced changes in fracture moisture content. At the end of the subsequent four-year cooling period, air-permeability decreases (to as low as 0.2 of initial) and increases (to as high as 1.8 of initial) were observed. By comparison to the calculated thermo-hydro-elastic model results, we identified these remaining increases or decreases in air permeability as irreversible changes in intrinsic fracture permeability, consistent with either inelastic fracture shear dilation (where permeability increased) or inelastic fracture surface asperity shortening (where permeability decreased). In this paper, we discuss the possibility that such fracture asperity shortening and associated decrease in fracture permeability might be enhanced by dissolution of highly stressed surface asperities over years of elevated stress and temperature.

Rutqvist, J.; Freifeld, B.; Min, K.-B.; Elsworth, D.; Tsang, Y.

2008-06-01T23:59:59.000Z

78

Effect of non-linear loading paths on sheet metal fracture : large strain in-plane compression followed by uniaxial tension  

E-Print Network [OSTI]

Advanced high strength steel sheets are rapidly entering the transport industry, as their high strength to weight ratio helps improving fuel and costs efficiency. The early ductile fracture of these materials limits their ...

Marcadet, Stephane (Stephane Jean Marie)

2012-01-01T23:59:59.000Z

79

Infiltration and Seepage Through Fractured Welded Tuff  

SciTech Connect (OSTI)

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.

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

2006-06-20T23:59:59.000Z

80

E-Print Network 3.0 - aperture radar intensity Sample Search...  

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

radar must have a large power-aperture product. Second, in order to obtain accurate wind velocities... arrays. The early radars could be pointed in only a few, Fig. 1. RHI...

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


81

E-Print Network 3.0 - aperture radar 3d Sample Search Results  

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

would be inefficient to use the large aperture radar... PTGTGR 2 (dB) RadarFunction (dB) Weather Target Table 3. ... Source: Reuter, Martin - NMR Athinoula A. Martinos Center,...

82

Hydraulic fracturing in a naturally fractured reservoir  

SciTech Connect (OSTI)

Hydraulic fracturing of wells in naturally fractured reservoirs can differ dramatically from fracturing wells in conventional isotropic reservoirs. Fluid leakoff is the primary difference. In conventional reservoirs, fluid leakoff is controlled by reservoir matrix and fracture fluid parameters. The fluid leakoff rate in naturally fractured reservoirs is typically excessive and completely dominated by the natural fractures. This paper presents several field examples of a fracture stimulation program performed on the naturally fractured Devonia carbonate of West Texas. Qualitative pressure decline analysis and net treating pressure interpretation techniques were utilized to evaluate the existence of natural fractures in the Devonian Formation. Quantitative techniques were utilized to assess the importance of the natural fractures to the fracturing process. This paper demonstrates that bottomhole pressure monitoring of fracture stimulations has benefits over conducting minifrac treatments in naturally fractured reservoirs. Finally, the results of this evaluation were used to redesign fracture treatments to ensure maximum productivity and minimize costs.

Britt, L.K.; Hager, C.J.; Thompson, J.W.

1994-12-31T23:59:59.000Z

83

Definition: Interferometric Synthetic Aperture Radar | Open Energy  

Open Energy Info (EERE)

Interferometric Synthetic Aperture Radar Interferometric Synthetic Aperture Radar Jump to: navigation, search Dictionary.png Interferometric Synthetic Aperture Radar Interferometric Synthetic Aperture Radar (InSAR) utilizes SAR images from two different time periods to generate maps of surface deformation. The technique can potentially measure millimeter-scale changes in the Earth's surface.[1][2] View on Wikipedia Wikipedia Definition Also Known As InSAR, IfSAR Related Terms Synthetic Aperture Radar, radar, sustainability References ↑ Synthetic Aperture Radar Interferometry to Measure Earth's Surface Topography and Its Deformation (Burgmann et al. 2000) ↑ Improved Visulaization of Satellite Radar InSAR Observed Structural Controls at Producing Geothermal Field Using Modeled Horizontal Surface Displacements(Opplinger et al. 2006)

84

Aperture Effects on Spectroscopic Galaxy Activity Classification  

E-Print Network [OSTI]

Activity classification of galaxies based on long-slit and fiber spectroscopy can be strongly influenced by aperture effects. Here we investigate how activity classification for 14 nearby galaxies depends on the proportion of the host galaxy's light that is included in the aperture. We use both observed long-slit spectra and simulated elliptical-aperture spectra of different sizes. The degree of change varies with galaxy morphology and nuclear activity type. Starlight removal techniques can mitigate but not remove the effect of host galaxy contamination in the nuclear aperture. Galaxies with extra-nuclear star formation can show higher [O III] {\\lambda}5007/H{\\beta} ratios with increasing aperture, in contrast to the naive expectation that integrated light will only dilute the nuclear emission lines. We calculate the mean dispersion for the diagnostic line ratios used in the standard BPT diagrams with respect to the central aperture of spectral extraction to obtain an estimate of the uncertainties resulting f...

Maragkoudakis, A; Ashby, M L N; Willner, S P

2014-01-01T23:59:59.000Z

85

Ion mobility spectrometer with virtual aperture grid  

DOE Patents [OSTI]

An ion mobility spectrometer does not require a physical aperture grid to prevent premature ion detector response. The last electrodes adjacent to the ion collector (typically the last four or five) have an electrode pitch that is less than the width of the ion swarm and each of the adjacent electrodes is connected to a source of free charge, thereby providing a virtual aperture grid at the end of the drift region that shields the ion collector from the mirror current of the approaching ion swarm. The virtual aperture grid is less complex in assembly and function and is less sensitive to vibrations than the physical aperture grid.

Pfeifer, Kent B. (Los Lunas, NM); Rumpf, Arthur N. (Albuquerque, NM)

2010-11-23T23:59:59.000Z

86

Hydraulic fracturing-1  

SciTech Connect (OSTI)

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

Not Available

1990-01-01T23:59:59.000Z

87

theoretical and applied fracture  

E-Print Network [OSTI]

theoretical and applied fracture mechanics ELSEVIER Theoretical and Applied Fracture Mechanics 00 and Applied Fracture Mechanics 00 (1995) 000-000 Recently, some European countries developed defect specific. A suitable probabilistic fracture mechanic

Cizelj, Leon

88

Definition: Synthetic Aperture Radar | Open Energy Information  

Open Energy Info (EERE)

Aperture Radar Aperture Radar Jump to: navigation, search Dictionary.png Synthetic Aperture Radar Synthetic-aperture radar (SAR) is an active microwave remote sensing technology that measures the phase difference between a radar wave emitted from an antennae attached to a satellite or aircraft to generate high-resolution images of a surface.[1] View on Wikipedia Wikipedia Definition Also Known As SAR Related Terms radar References ↑ Synthetic Aperature Radar: Systems and Signal Processing (Curlander and McDonough - 1991 - book) fue LikeLike UnlikeLike You like this.Sign Up to see what your friends like. l cell, Retrieved from "http://en.openei.org/w/index.php?title=Definition:Synthetic_Aperture_Radar&oldid=493069" Category: Definitions What links here Related changes

89

Variable aperture collimator for high energy radiation  

DOE Patents [OSTI]

An apparatus is disclosed providing a variable aperture energy beam collimator. A plurality of beam opaque blocks are in sliding interface edge contact to form a variable aperture. The blocks may be offset at the apex angle to provide a non-equilateral aperture. A plurality of collimator block assemblies may be employed for providing a channel defining a collimated beam. Adjacent assemblies are inverted front-to-back with respect to one another for preventing noncollimated energy from emerging from the apparatus. An adjustment mechanism comprises a cable attached to at least one block and a hand wheel mechanism for operating the cable. The blocks are supported by guide rods engaging slide brackets on the blocks. The guide rods are pivotally connected at each end to intermediate actuators supported on rotatable shafts to change the shape of the aperture. A divergent collimated beam may be obtained by adjusting the apertures of adjacent stages to be unequal.

Hill, Ronald A. (Albuquerque, NM)

1984-05-22T23:59:59.000Z

90

Numerical Investigation of Interaction Between Hydraulic Fractures and Natural Fractures  

E-Print Network [OSTI]

Hydraulic fracturing of a naturally-fractured reservoir is a challenge for industry, as fractures can have complex growth patterns when propagating in systems of natural fractures in the reservoir. Fracture propagation near a natural fracture (NF...

Xue, Wenxu

2011-02-22T23:59:59.000Z

91

Coupled processes in single fractures, double fractures and fractured porous media  

SciTech Connect (OSTI)

The emplacement of a nuclear waste repository in a fractured porous medium provides a heat source of large dimensions over an extended period of time. It also creates a large cavity in the rock mass, changing significantly the stress field. Such major changes induce various coupled thermohydraulic, hydromechanic and hydrochemical transport processes in the environment around a nuclear waste repository. The present paper gives, first, a general overview of the coupled processes involving thermal, mechanical, hydrological and chemical effects. Then investigations of a number of specific coupled processes are described in the context of fluid flow and transport in a single fracture, two intersecting fractures and a fractured porous medium near a nuclear waste repository. The results are presented and discussed.

Tsang, C.F.

1986-12-01T23:59:59.000Z

92

A COST OPTIMIZED SMALL APERTURE 2 IN 1 VLHC.  

SciTech Connect (OSTI)

Although one must recognize that parametric studies like this are not equivalent to real cost estimates: one can draw some probable conclusions. Clearly, in all cases, there is a cost optimum: at higher fields, magnet costs rise disproportionally; at low fields tunnel and other linear costs are excessive. Fields above 10 T and bellow 3 T appear to be uneconomic. Field in the 4-6 T range seem optimum. Better superconductors raise the optimum field, but by surprisingly small amounts, and offer only small savings. On the other hand, reducing the magnet apertures yield large savings. In particular, we find that a collider with SSC like energy could cost about half that of the SSC if built with 5 T magnets and apertures yielding an impedance equal to that for the proposed transmission line magnet ring. It would also be about half the cost of a ring made with those transmission line magnets.

PALMER,R.B.; PARKER,B.; FOSTER,G.W.

2001-07-01T23:59:59.000Z

93

Borehole deviation surveys are necessary for hydraulic fracture monitoring Leo Eisner, Schlumberger Cambridge Research, Petr Bulant, Charles University in Prague, Jol H. Le Calvez*,  

E-Print Network [OSTI]

Borehole deviation surveys are necessary for hydraulic fracture monitoring Leo Eisner, Schlumberger Not performing accurate borehole deviation surveys for hydraulic fracture monitoring (HFM) and neglecting fracture parameters. Introduction Recently a large number of hydraulic fracture treatments have been

Cerveny, Vlastislav

94

Iterative synthetic aperture radar imaging algorithms   

E-Print Network [OSTI]

Synthetic aperture radar is an important tool in a wide range of civilian and military imaging applications. This is primarily due to its ability to image in all weather conditions, during both the day and the night, ...

Kelly, Shaun Innes

2014-06-30T23:59:59.000Z

95

LED Emission through Sub-Wavelength Apertures  

Science Journals Connector (OSTI)

A gold film with a hexagonal array of sub-wavelength apertures has been fabricated onto the emitting surface of a semiconductor light emitting diode. Interaction of the light with...

Harries, Michael D; Summers, Huw D

96

Multi-channel coded-aperture photography  

E-Print Network [OSTI]

This thesis describes the multi-channel coded-aperture photography, a modified camera system that can extract an all-focus image of the scene along with a depth estimate over the scene. The modification consists of inserting ...

Baek, Jongmin

2008-01-01T23:59:59.000Z

97

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

SciTech Connect (OSTI)

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

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

2008-07-01T23:59:59.000Z

98

Hydraulic fracturing in tight, fissured media  

SciTech Connect (OSTI)

Large volumes of natural gas are found in tight, fissured reservoirs. Hydraulic fracturing can enhance recovery, but many complications, such as pressure-sensitive or accelerated leakoff, damage, and complex fracturing, arise during treatment of such reservoirs. This paper reports that special procedures generally should be considered during breakdown and fracturing of these reservoirs. In addition, the use of alternative stimulation strategies may be beneficial.

Warpinski, N.R. (Sandia National Lab., Albuquerque, NM (US))

1991-02-01T23:59:59.000Z

99

Prediction of effects of hydraulic fracturing using reservoir and well flow simulation  

SciTech Connect (OSTI)

This paper presents a method to predict and evaluate effects of hydraulic fracturing jobs by using reservoir and well flow numerical simulation. The concept of the method i5 that steam production rate at the operating well head pressure is predicted with different fracture conditions which would be attained by the hydraulic fracturing jobs. Then, the effects of the hydraulic fracturing is evaluated by comparing the predicted steam production rate and that before the hydraulic fracturing. This course of analysis will suggest how large fracture should be created by the fracturing job to attain large enough increase in steam production at the operating condition and the best scheme of the hydraulic fracturing job.

Mineyuki Hanano; Tayuki Kondo

1992-01-01T23:59:59.000Z

100

Fracture Properties From Seismic Scattering  

E-Print Network [OSTI]

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

Burns, Daniel R.

2007-01-01T23:59:59.000Z

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


101

Seismic characterization of fractures  

E-Print Network [OSTI]

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

JM Carcione

2014-06-07T23:59:59.000Z

102

Accounting for Remaining Injected Fracturing Fluid  

E-Print Network [OSTI]

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...

Zhang, Yannan

2013-12-06T23:59:59.000Z

103

The design of a large aperture high field dipole  

SciTech Connect (OSTI)

The impetus for this design report originated in the Snowmass 88 meeting where the subject of higher energies within the constraints of the existing Tevatron tunnel enclosure was investigated. It was determined that beam transport to the fixed target experimental areas was possible up to an energy of {approximately}1.5 Tev. Collider operation was feasible at somewhat higher energies (1.8 Tev), primarily limited by the ability to design a single turn beam abort system within the constraints of the straight section length. A new accelerator in the existing tunnel would, of necessity, have a similar though not identical lattice and straight section layout to the present Tevatron. Thus when issues arose in the magnet design requiring input from the accelerator standpoint we have assumed a Tevatron like machine. The possibility of using these high field magnets as elements in the existing Tevatron to create new warm space,' for another Interaction Region for example, also emphasizes compatibility with the present machine. 16 refs., 62 figs., 23 tabs.

Harfoush, F.; Harrison, M.; Kerby, J.; Koepke, K.; Mantsch, P.; Nicol, T.; Riddiford, A.; Theilacker, J.

1989-12-01T23:59:59.000Z

104

Photovoltaic converter having apertured reflective enclosure  

SciTech Connect (OSTI)

This patent describes a photovoltaic converter. It comprises: a photovoltaic cell having an incident face upon which light is directed to cause photogeneration; an enclosure over the incident face, the wall of the enclosure having a reflective inner surface spaced apart from the incident face to permit light reflected from the incident face to be re-reflected by the inner surface and back to the photovoltaic cell; and an aperture through the wall of the enclosure to permit light to fall directly upon the voltaic cell. The ratio of the area of the aperture to the are of the incident face of the photovoltaic cell is less than about 0.2.

Sinton, R.A.; Swanson, R.M.

1990-10-02T23:59:59.000Z

105

Hydraulic fractur ing--also called hy  

E-Print Network [OSTI]

Hydraulic fractur ing--also called hy drofracking or frack ing--is a process where large volumes) is an aquatic invasive spe cies listed on the USDA's federal noxious weeds list (http:// www.aphis.usda.gov/plant_health

Goodman, Robert M.

106

Determination of the linear aperture of the SSC (Superconducting Supercollider) clustered lattice used for the conceptual design report  

SciTech Connect (OSTI)

A study is made of the linear aperture for the clustered lattice used for the SSC Conceptual Design Report. Random multipole errors are included in all magnetic elements including the insertion dipoles and quadrupoles. Based on the concept of smear, the linear aperture is equal to the dynamic aperture in the range -0.1 less than or equal to ..delta..P/P less than or equal to 0.03%. Strong coupling for ..delta..P/P > 0% produces large smears. A variation of the smear parameter that is insensitive to coupling is proposed. A comparison is made with results reported in the SSC Conceptual Design Report.

Dell, G.F.

1986-06-23T23:59:59.000Z

107

Efficient Geomechanical Simulations of Large-Scale Naturally Fractured Reservoirs Using the Fast Multipole-Displacement Discontinuity Method (FM-DDM)  

E-Print Network [OSTI]

....................................................................... 63 5.2.2. FED model evaluation – Cases 5 and 6 .......................................................... 66 5.2.3. FPDD model evaluation – Case 7 .................................................................. 73 6. NUMERICAL APPLICATIONS... to injection – Case 3. ......... 89 6.4. Fluid injection and production in large-scale poroelastic shales – Case 4. ........... 92 7. CONCLUSIONS AND RECOMMENDATIONS ....................................................... 99 7.1. Conclusions...

Verde Salas, Alexander José

2014-04-28T23:59:59.000Z

108

Instrument Design Simulations for Synthetic Aperture Microwave Radiometric Imaging of Wind Speed and  

E-Print Network [OSTI]

Instrument Design Simulations for Synthetic Aperture Microwave Radiometric Imaging of Wind Speed, US Abstract -- The measurement of peak winds in hurricanes is critical to forecasting intensity in radiative transfer modeling for hurricane force winds and large incidence angles are required for HIRad

Ruf, Christopher

109

Correction schemes to improve the dynamical aperture of the Main Injector  

SciTech Connect (OSTI)

Tracking simulations have revealed that the dominant factors limiting the dynamical aperture of the Main Injector are the large octupole component and the random errors in the recycled Main Ring quadrupoles. This paper describes a correction scheme that reduces the effect of these errors on the performance of the Fermilab Main Injector, especially for the slow extraction operation.

Mishra, C.S.; Harfoush, F.A.

1993-07-01T23:59:59.000Z

110

Dual aperture dipole magnet with second harmonic component  

DOE Patents [OSTI]

An improved dual aperture dipole electromagnet includes a second-harmonic frequency magnetic guide field winding which surrounds first harmonic frequency magnetic guide field windings associated with each aperture. The second harmonic winding and the first harmonic windings cooperate to produce resultant magnetic waveforms in the apertures which have extended acceleration and shortened reset portions of electromagnet operation.

Praeg, W.F.

1983-08-31T23:59:59.000Z

111

Vacuum aperture isolator for retroreflection from laser-irradiated target  

DOE Patents [OSTI]

The disclosure is directed to a vacuum aperture isolator for retroreflection of a laser-irradiated target. Within a vacuum chamber are disposed a beam focusing element, a disc having an aperture and a recollimating element. The edge of the focused beam impinges on the edge of the aperture to produce a plasma which refracts any retroreflected light from the laser's target.

Benjamin, Robert F. (Los Alamos, NM); Mitchell, Kenneth B. (Los Alamos, NM)

1980-01-01T23:59:59.000Z

112

A typical Ztrack'' long-term tracking result for the SSC aperture study  

SciTech Connect (OSTI)

A large amount of supercomputer CPU time has been used for tracking particles in the Superconducting Super Collider (SSC) using a vectorized, multi-tasked post-Teapot tracking program called Ztrack.'' Typically, hundreds of particles with appropriate initial displacements (relative to the closed orbits) are tracked for a hundred thousand turns. One then simply makes a survival plot (turn at which particle is lost versus initial displacements) to determine the dynamic aperture. Occasionally, particles are tracked to a million turns for very selective cases. These numerical studies aid in determining the best aperture for the SSC. 6 refs., 1 fig., 1 tab.

Yan, Y.; Bourianoff, G. (Superconducting Super Collider Lab., Dallas, TX (USA)); Schachinger, L. (Lawrence Berkeley Lab., CA (USA))

1990-12-01T23:59:59.000Z

113

Fracture history of the Northern Piceance Creek Basin, Northwestern Colorado  

SciTech Connect (OSTI)

The fracture pattern of the Northern Piceance Creek Basin, in Rio Blanco and Garfield Counties of Northwestern Colorado, evolved during at least four periods of brittle failure in Eocene rocks of the Green River and overlying Uinta Formations. Fractures in these rocks of are interest to hydrologists because matrix permeabilities in both formations are low, due either to poor sorting and interstitial calcite cement (Uinta sandstones) or to low pore volume and growth of authigenic minerals (Green River oil shales). Ground water at shallow to intermediate depths thus circulates mostly through secondary openings such as fractures and through voids created by the dissolution of nahcolite and halite. Fracture-induced permeabilities probably dominate most at shallow depths, where fractures are most abundant, apertures of fracture walls are greates, and solution openings are least common. Shallow, fracture-dominated aquifers are strongly anisotropic. At deeper levels, in leached zones of the ''saline facies'' of the lower part of the Green River Formation, solution openings contribute greatly to fluid flow and permeabilities probably are less direction dependent.

Verbeek, E.R.; Grout, M.A.

1983-04-01T23:59:59.000Z

114

Hydraulic Fracturing Technology | Department of Energy  

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

Oil & Gas » Shale Gas » Hydraulic Oil & Gas » Shale Gas » Hydraulic Fracturing Technology Hydraulic Fracturing Technology Image taken from "Shale Gas: Applying Technology to Solve America's Energy Challenges," NETL, 2011. Image taken from "Shale Gas: Applying Technology to Solve America's Energy Challenges," NETL, 2011. Hydraulic fracturing is a technique in which large volumes of water and sand, and small volumes of chemical additives are injected into low-permeability subsurface formations to increase oil or natural gas flow. The injection pressure of the pumped fluid creates fractures that enhance gas and fluid flow, and the sand or other coarse material holds the fractures open. Most of the injected fluid flows back to the wellbore and is pumped to the surface.

115

Spatially Interpolated Nonlinear Anodization in Synthetic Aperture Radar Imagery  

SciTech Connect (OSTI)

Spatially Interpolated Nonlinear Anodization in Synthetic Aperture Original formulation of spatially variant anodization for complex synthetic aperture radar (SAR) imagery oversampled at twice the Nyquist rate (2.OX). Here we report a spatially interpolating, noninteger-oversampled SVA sidelobe. The pixel's apparent IPR location is assessed by comparing its value to the sum of its value plus weighted comparable for exact interpolation. However, exact interpolation implies an ideal sine interpolator3 and large components may not be necessary. Note that P is the summation of IPR diagonal values. The value of a sine IPR on the diagonals is a sine-squared; values much less than cardinal direction (m, n) values. This implies that cardinal direction interpolation requires higher precision than diagonal interpolation. Consequently, we employed a smaller set. The spatially interpolated SVA used an 8-point/4-point sine interpolator described above. Table 1 shows the Table 1 results show a two-times speed-up using the 1.3x oversampled and spatially interpolated SVA over the Figure 1d. Detected results of 1.3x oversampled sine interpolated spatially variant

Eichel, Paul H.; Jakowatz, Jr., Charles V.; Yocky, David A.

1999-06-29T23:59:59.000Z

116

E-Print Network 3.0 - acoustics synthetic aperture Sample Search...  

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

Synthetic aperture focusing... Introduction Synthetic aperture focusing techniques (SAFT) ... Source: Uppsala Universitet, Department of Material Science, Signals and Systems...

117

Synthetic aperture radar processing with tiered subapertures  

SciTech Connect (OSTI)

Synthetic Aperture Radar (SAR) is used to form images that are maps of radar reflectivity of some scene of interest, from range soundings taken over some spatial aperture. Additionally, the range soundings are typically synthesized from a sampled frequency aperture. Efficient processing of the collected data necessitates using efficient digital signal processing techniques such as vector multiplies and fast implementations of the Discrete Fourier Transform. Inherent in image formation algorithms that use these is a trade-off between the size of the scene that can be acceptably imaged, and the resolution with which the image can be made. These limits arise from migration errors and spatially variant phase errors, and different algorithms mitigate these to varying degrees. Two fairly successful algorithms for airborne SARs are Polar Format processing, and Overlapped Subaperture (OSA) processing. This report introduces and summarizes the analysis of generalized Tiered Subaperture (TSA) techniques that are a superset of both Polar Format processing and OSA processing. It is shown how tiers of subapertures in both azimuth and range can effectively mitigate both migration errors and spatially variant phase errors to allow virtually arbitrary scene sizes, even in a dynamic motion environment.

Doerry, A.W. [Sandia National Labs., Albuquerque, NM (United States). Synthetic Aperture Radar Dept.

1994-06-01T23:59:59.000Z

118

Characterizing fractured rock for fluid-flow, geomechanical, and paleostress modeling: Methods and preliminary results from Yucca Mountain, Nevada  

SciTech Connect (OSTI)

Fractures have been characterized for fluid-flow, geomechanical, and paleostress modeling at three localities in the vicinity of drill hole USW G-4 at Yucca Mountain in southwestern Nevada. A method for fracture characterization is introduced that integrates mapping fracture-trace networks and quantifying eight fracture parameters: trace length, orientation, connectivity, aperture, roughness, shear offset, trace-length density, and mineralization. A complex network of fractures was exposed on three 214- to 260-m 2 pavements cleared of debris in the upper lithophysal unit of the Tiva Canyon Member of the Miocene Paint-brush Tuff. The pavements are two-dimensional sections through the three-dimensional network of strata-bound fractures. All fractures with trace lengths greater than 0.2 m were mapped and studied.

Barton, C.C.; Larsen, E.; Page, W.R.; Howard, T.M.

1993-12-31T23:59:59.000Z

119

Parameters for HL-LHC aperture calculations and comparison with aperture measurements  

E-Print Network [OSTI]

When ?? is squeezed to smaller values in the LHC, the beam size in the inner triplet increases so that the aperture risks to be exposed to unwanted beam losses. A 2D calculation model was used during the design stage to study the aperture margins, both there and at other potential bottlenecks. Based on assumptions on orbit and optics errors, as well as mechanical tolerances, it gives the available aperture in units of the RMS beam size, which can be compared with what can be protected by the collimation system. During the LHC Run I in 2010-2013, several of the error tolerances have been found smaller than the design assumptions. Furthermore, the aperture has been measured with beam several times and the results are compatible with a very well aligned machine, with results close to the design values. In this report, we therefore review the assumptions in the model and propose an updated set of input parameters to be used for aperture calculations at top energy in HL-LHC. The new parameter set is based on th...

Bruce, R; Fartoukh, S; Giovannozzi, M; Redaelli, S; Tomas, R; Wenninger, J

2014-01-01T23:59:59.000Z

120

Hydraulic Fracturing Simulation of Complex Fractures Growth in Naturally Fractured Shale Gas Reservoir  

Science Journals Connector (OSTI)

Hydraulic fracturing is regarded as one of the essential techniques for developing shale reservoirs at present. During fracturing, propagation of multi-fractures and complex fracture network is developed as re...

Wang Song; Zhao Jinzhou; Li Yongming

2014-10-01T23:59:59.000Z

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


121

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

E-Print Network [OSTI]

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

Forbis, Robert E.

2014-01-01T23:59:59.000Z

122

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

SciTech Connect (OSTI)

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.

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

1997-08-01T23:59:59.000Z

123

Synthetic Aperture Radar Persistent Scatterer Interferometry (PSInSAR) |  

Open Energy Info (EERE)

Synthetic Aperture Radar Persistent Scatterer Interferometry (PSInSAR) Synthetic Aperture Radar Persistent Scatterer Interferometry (PSInSAR) Jump to: navigation, search OpenEI Reference LibraryAdd to library Web Site: Synthetic Aperture Radar Persistent Scatterer Interferometry (PSInSAR) Author Parviz Tarikhi Published N/A, 2010 DOI Not Provided Check for DOI availability: http://crossref.org Online Internet link for Synthetic Aperture Radar Persistent Scatterer Interferometry (PSInSAR) Citation Parviz Tarikhi. Synthetic Aperture Radar Persistent Scatterer Interferometry (PSInSAR) [Internet]. 2010. Tunis, Tunisia. N/A. [cited 2013/09/17]. Available from: http://parviztarikhi.files.wordpress.com/2010/05/3psinsar-i-parviz_tarikhi.pdf Retrieved from "http://en.openei.org/w/index.php?title=Synthetic_Aperture_Radar_Persistent_Scatterer_Interferometry_(PSInSAR)&oldid=682949"

124

Self-potential observations during hydraulic fracturing  

E-Print Network [OSTI]

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

Moore, J R; Glaser, Steven D

2007-01-01T23:59:59.000Z

125

Self-potential observations during hydraulic fracturing  

E-Print Network [OSTI]

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

Moore, Jeffrey R.; Glaser, Steven D.

2008-01-01T23:59:59.000Z

126

Hydraulic fracture mechanism in unconsolidated formations.  

E-Print Network [OSTI]

??Most models developed for hydraulic fracturing in unconsolidated sands are based on Linear Elastic Fracture Mechanics (LEFM) and tensile fracture (Mode I fracture). However, in… (more)

Hosseini, Seyed Mehran

2012-01-01T23:59:59.000Z

127

Extraordinary optical transmission through patterned subwavelength apertures.  

SciTech Connect (OSTI)

Light propagating through a subwavelength aperture can be dramatically increased by etching a grating in the metal around the hole. Moreover, light that would typically broadly diverge when passing through an unpatterned subwavelength hole can be directed into a narrow beam by utilizing a specific pattern around the aperture. While the increased transmission and narrowed angular emission appear to defy far-field diffraction theory, they are consistent with a fortuitous plasmon/photon coupling. In addition, the coupling between photons and surface plasmons affects the emissivity of a surface comprised of such structures. These properties are useful across several strategic areas of interest to Sandia. A controllable emission spectrum could benefit satellite and military application areas. Photolithography and near-field microscopy are natural applications for a system that controls light beyond the diffraction limit in a manner that is easily parallelizable. Over the one year of this LDRD, we have built or modified the numerical tools necessary to model such structures. These numerical codes and the knowledge base for using them appropriately will be available in the future for modeling work on surface plasmons or other optical modeling at Sandia. Using these tools, we have designed and optimized structures for various transmission or emission properties. We demonstrate the ability to design a metallic skin with an emissivity peak at a pre-determined wavelength in the spectrum. We optimize structures for maximum light transmission and show transmitted beams that beat the far-field diffraction limit.

Kemme, Shanalyn A.; El-Kady, Ihab Fathy; Hadley, G. Ronald; Peters, David William; Lanes, Chris E.

2004-12-01T23:59:59.000Z

128

Diffraction from oxide confinement apertures in vertical-cavity lasers  

SciTech Connect (OSTI)

Direct measurement of scattered fields from oxide confinement apertures in vertical-cavity lasers is presented. Diffraction fringes associated with each transverse lasing mode are detected in the far field from devices with varying oxide aperture dimensions and with quantum efficiencies as high as 48{percent}. The diffracted pattern symmetries match the rectangular symmetry of the oxide apertures present in the devices and fringe locations are compared to Fraunhofer theory. The fraction of power diffracted from the lasing mode remains roughly constant as a function of relative pump rate, but is shown to depend on both transverse mode order and oxide aperture size. {copyright} {ital 1999 American Institute of Physics.}

Roos, P.A.; Carlsten, J.L. [Montana State University, Department of Physics, Bozeman, Montana 59717 (United States)] [Montana State University, Department of Physics, Bozeman, Montana 59717 (United States); Kilper, D.C. [University of North Carolina at Charlotte, Department of Physics, Charlotte, North Carolina 28223 (United States)] [University of North Carolina at Charlotte, Department of Physics, Charlotte, North Carolina 28223 (United States); Lear, K.L. [MicroOptical Devices Inc., 5601C Midway Park Pl. NE, Albuquerque, New Mexico 87109 (United States)] [MicroOptical Devices Inc., 5601C Midway Park Pl. NE, Albuquerque, New Mexico 87109 (United States)

1999-08-01T23:59:59.000Z

129

Single molecule fluorescence in rectangular nano-apertures  

Science Journals Connector (OSTI)

Fluorescence Correlation Spectroscopy is used to investigate fluorescent molecules in solution diffusing in subwavelength rectangular apertures milled in Aluminium films. This...

Wenger, Jérôme; Lenne, Pierre-François; Popov, Evgueni; Rigneault, Hervé; Dintinger, José; Ebbesen, Thomas

2005-01-01T23:59:59.000Z

130

Functionalized apertures for the detection of chemical and biological materials  

DOE Patents [OSTI]

Disclosed are nanometer to micron scale functionalized apertures constructed on a substrate made of glass, carbon, semiconductors or polymeric materials that allow for the real time detection of biological materials or chemical moieties. Many apertures can exist on one substrate allowing for the simultaneous detection of numerous chemical and biological molecules. One embodiment features a macrocyclic ring attached to cross-linkers, wherein the macrocyclic ring has a biological or chemical probe extending through the aperture. Another embodiment achieves functionalization by attaching chemical or biological anchors directly to the walls of the apertures via cross-linkers.

Letant, Sonia E. (Livermore, CA); van Buuren, Anthony W. (Livermore, CA); Terminello, Louis J. (Danville, CA); Thelen, Michael P. (Danville, CA); Hope-Weeks, Louisa J. (Brentwood, CA); Hart, Bradley R. (Brentwood, CA)

2010-12-14T23:59:59.000Z

131

Simulation of Hydraulic Fractures and their Interactions with Natural Fractures  

E-Print Network [OSTI]

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...

Sesetty, Varahanaresh

2012-10-19T23:59:59.000Z

132

Fracture characterization from attenuation of Stoneley waves across a fracture  

E-Print Network [OSTI]

Fractures contribute significantly to the permeability of a formation. It is important to understand the fracture distribution and fluid transmissivity. Though traditional well logs can image fractures intersecting the ...

Bakku, Sudhish Kumar

2012-01-01T23:59:59.000Z

133

Specification of fields quality in the interaction region magnets of the high luminosity LHC based on dynamic aperture  

E-Print Network [OSTI]

New large aperture Inner Triplet quadrupoles, separation dipoles and the nearby matching quadrupoles will be installed in the low-beta interaction regions (IR) of the high luminosity LHC upgrade (HL-LHC) [1]. The large aperture is necessary for accommodating the increased beam size due to much higher beta functions in these magnets for the low collision optics. The high beta functionswill amplify the effects of field errors in the new magnets leading to a smaller dynamic aperture (DA). It is, therefore, critical to evaluate the impact of these errors on the DA and specify the magnet field quality (FQ) satisfying an acceptable DA while being realistically achievable. The study is performed for the HL-LHC lattice layouts SLHCV3.1b and HLLHCV1.0 for collision and injection energies.

Nosochkov, Y; Wang, M H; Fartoukh, S; Giovannozzi, M; De Maria, R; McIntosh, E

2014-01-01T23:59:59.000Z

134

TEMPORAL VARIATIONS OF FRACTURE DIRECTIONS AND FRACTURE DENSITIES...  

Open Energy Info (EERE)

TEMPORAL VARIATIONS OF FRACTURE DIRECTIONS AND FRACTURE DENSITIES IN THE COSO GEOTHERMAL FIELD FROM ANALYSES OF SHEAR-WAVE SPLITTING Jump to: navigation, search OpenEI Reference...

135

A Rare Isolated Trapezoid Fracture  

E-Print Network [OSTI]

wrist in suggested scaphoid fracture. Acta Radiol. 1988;29:Rare isolated trapezoid fracture: a case report. Hand. 2008;suspect and diagnose this fracture. 2,8 REFERENCES 1. Papp

Afifi, Negean; Lu, Jenny J

2011-01-01T23:59:59.000Z

136

Synthetic aperture design for increased SAR image rate  

DOE Patents [OSTI]

High resolution SAR images of a target scene at near video rates can be produced by using overlapped, but nevertheless, full-size synthetic apertures. The SAR images, which respectively correspond to the apertures, can be analyzed in sequence to permit detection of movement in the target scene.

Bielek, Timothy P. (Albuquerque, NM); Thompson, Douglas G. (Albuqerque, NM); Walker, Bruce C. (Albuquerque, NM)

2009-03-03T23:59:59.000Z

137

FODO-Supercell Based Compact Ring Design with Tunable Momentum Compaction and Optimized Dynamic Aperture  

SciTech Connect (OSTI)

A storage ring with tunable momentum compaction has the advantage in achieving different RMS bunch length with similar RF capacity, which is potentially useful for many applications, such as linear collider damping ring and pre-damping ring where injected beam has a large energy spread and a large transverse emittance. A tunable bunch length also makes the commissioning and fine tuning easier in manipulating the single bunch instabilities. In this paper, a compact ring design based on a supercell is presented, which achieves a tunable momentum compaction while maintaining a large dynamic aperture.

Sun, Yipeng; /SLAC

2012-05-11T23:59:59.000Z

138

Inversion of synthetic aperture radar interferograms for sources of  

Open Energy Info (EERE)

Inversion of synthetic aperture radar interferograms for sources of Inversion of synthetic aperture radar interferograms for sources of production-related subsidence at the Dixie Valley geothermal field Jump to: navigation, search OpenEI Reference LibraryAdd to library Journal Article: Inversion of synthetic aperture radar interferograms for sources of production-related subsidence at the Dixie Valley geothermal field Authors Bill Foxall and D. W. Vasco Published Journal Journal of Volcanology and Geothermal Research, 2008 DOI Not Provided Check for DOI availability: http://crossref.org Online Internet link for Inversion of synthetic aperture radar interferograms for sources of production-related subsidence at the Dixie Valley geothermal field Citation Bill Foxall,D. W. Vasco. 2008. Inversion of synthetic aperture radar interferograms for sources of production-related subsidence at the Dixie

139

On the Theory of Diffraction by an Aperture in an Infinite Plane Screen. II.  

Science Journals Connector (OSTI)

The diffraction of a scalar plane wave by an aperture in an infinite plane screen is examined theoretically. The wave function at an arbitrary point of space is expressed in terms of the discontinuity in its normal derivative at the screen, where the boundary condition is that of vanishing wave function. An integral equation for the discontinuity in normal derivative (or the residual function which measures its deviation from the simple distribution appropriate to a completely infinite screen) is the result of applying the boundary condition to the space wave function. Utilizing the integral equation (whose solution is generally unobtainable), the diffracted spherical wave amplitude at large distances from the aperture is cast into a form which is stationary with respect to small variations (relative to the correct values) of the residual functions arising from a pair of incident waves. An homogeneous expression for the amplitude is exhibited wherein the part independent of the residual functions defines a Kirchoff approximation. The connection with another stationary form of the amplitude, involving a pair of aperture wave functions, is examined. A variational expression for the plane wave transmission cross section of the aperture is based on the amplitude observed in the direction of incidence. The variational formulation is applied for a wave incident normally on a circular aperture. By comparison with the exact results available for this problem, it appears that use of simple residual functions in the variational formulation yields approximate, yet accurate expressions for the diffracted amplitude and transmission cross section over a wide range of frequencies.

Harold Levine and Julian Schwinger

1949-05-01T23:59:59.000Z

140

Hydraulic Fracturing in Particulate Materials.  

E-Print Network [OSTI]

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

Chang, Hong

2004-01-01T23:59:59.000Z

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


141

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

E-Print Network [OSTI]

Low-permeability gas wells often produce less than predicted after a fracture treatment. One of the reasons for this is that fracture lengths calculated after stimulation are often less than designed lengths. While actual fracture lengths may...

Lolon, Elyezer P.

2006-04-12T23:59:59.000Z

142

Mapping Fractures In The Medicine Lake Geothermal System | Open Energy  

Open Energy Info (EERE)

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

143

Flow focusing in unsaturated fracture networks: A numerical investigation  

SciTech Connect (OSTI)

A numerical modeling study is presented to investigate flow-focusing phenomena in a large-scale fracture network, constructed using field data collected from the unsaturated zone of Yucca Mountain, Nevada, the proposed repository site for high-level nuclear waste. The two-dimensional fracture network for an area of 100 m x 150 m contains more than 20,000 fractures. Steady-state unsaturated flow in the fracture network is investigated for different boundary conditions and rock properties. Simulation results indicate that flow paths are generally vertical, and that horizontal fractures mainly provide pathways between neighboring vertical paths. In addition to fracture properties, flow-focusing phenomena are also affected by rock-matrix permeability, with lower matrix permeability leading to a high degree of flow focusing. The simulation results further indicate that the average spacing between flow paths in a layered system tends to increase and flow tends to becomes more focused, with depth.

Zhang, Keni; Wu, Yu-Shu; Bodvarsson, G.S.; Liu, Hui-Hai

2003-04-17T23:59:59.000Z

144

INVESTIGATION OF EFFICIENCY IMPROVEMENTS DURING CO2 INJECTION IN HYDRAULICALLY AND NATURALLY FRACTURED RESERVOIRS  

SciTech Connect (OSTI)

The objective of this project is to perform unique laboratory experiments with artificial fractured cores (AFCs) and X-ray CT to examine the physical mechanisms of bypassing in HFR and NFR that eventually result in more efficient CO{sub 2} flooding in heterogeneous or fracture-dominated reservoirs. To achieve this objective, we divided the report into two chapters. The first chapter was to image and perform experimental investigation of transfer mechanisms during CO{sub 2} flooding in NFR and HFR using X-ray CT scanner. In this chapter, we emphasized our work on understanding the connection between fracture properties and fundamentals of transfer mechanism from matrix to fractures and fluid flow through fracture systems. We started our work by investigating the effect of different overburden pressures and stress-state conditions on rock properties and fluid flow. Since the fracture aperture is one of important parameter that governs the fluid flow through the fracture systems, the average fracture aperture from the fluid flow experiments and fracture aperture distribution derived from X-ray CT scan were estimated for our modeling purposes. The fracture properties and fluid flow have significant changes in response to different overburden pressures and stress-state conditions. The fracture aperture distribution follows lognormal distribution even at elevated stress conditions. Later, we also investigated the fluid transfers between matrix and fracture that control imbibition process. We evaluated dimensionless time for validating the scheme of upscaling laboratory experiments to field dimensions. In CO{sub 2} injection experiments, the use of X-ray CT has allowed us to understand the mechanisms of CO{sub 2} flooding process in fractured system and to take important steps in reducing oil bypassed. When CO{sub 2} flooding experiments were performed on a short core with a fracture at the center of the core, the gravity plays an important role in the recovery of oil even in a short matrix block. This results are contrary with the previous believes that gravity drainage has always been associated with tall matrix blocks. In order to reduce oil bypassed, we injected water that has been viscosified with a polymer into the fracture to divert CO{sub 2} flow into matrix and delay CO{sub 2} breakthrough. Although the breakthrough time reduced considerably, water ''leak off'' into the matrix was very high. A cross-linked gel was used in the fracture to avoid this problem. The gel was found to overcome ''leak off'' problems and effectively divert CO{sub 2} flow into the matrix. As part of our technology transfer activity, we investigated the natural fracture aperture distribution of Tensleep formation cores. We found that the measured apertures distributions follow log normal distribution as expected. The second chapter deals with analysis and modeling the laboratory experiments and fluid flow through fractured networks. We derived a new equation to determine the average fracture aperture and the amount of each flow through fracture and matrix system. The results of this study were used as the observed data and for validating the simulation model. The idea behind this study is to validate the use of a set of smooth parallel plates that is common in modeling fracture system. The results suggest that fracture apertures need to be distributed to accurately model the experimental results. In order to study the imbibition process in details, we developed imbibition simulator. We validated our model with X-ray CT experimental data from different imbibition experiments. We found that the proper simulation model requires matching both weight gain and CT water saturation simultaneously as oppose to common practices in matching imbibition process with weight gain only because of lack information from CT scan. The work was continued by developing dual porosity simulation using empirical transfer function (ETF) derived from imbibition experiments. This allows reduction of uncertainty parameter in modeling transfer of fluids from matrix to the fra

David S. Schechter

2005-09-28T23:59:59.000Z

145

Experimental observations of deformation caused by mineral dissolution in variable-aperture fractures  

E-Print Network [OSTI]

are further influenced by stresses in the host rock. To quantitatively explore these coupled processes, we-water reactions. For example, subsurface CO2 sequestration in depleted oil and gas reservoirs or deep saline 1 August 2008. [1] Problems such as CO2 sequestration, petroleum production and nuclear waste

Detwiler, Russell

146

3 RESERVOIR PERFORMANCE ANALYSIS 3.1 ANALYSIS OF IMBIBITION MECHANISM IN THE NATURALLY FRACTURED  

E-Print Network [OSTI]

these parameters and other key parameters in the oil recovery mechanism (i.e., matrix permeability, fracture.1.2 Concept of Process In the Spraberry reservoir, oil is stored in a very tight matrix, with virtually all permeability concentrated in a large number of natural fractures. Due to these fractures, oil cannot

Schechter, David S.

147

E-Print Network 3.0 - aperture radar processing Sample Search...  

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

sensors (Ex. TM, IKONOS, ERS) 3. Synthetic Aperture Radar... ;SPOT Image 12;Haiti Earthquake 12; Synthetic Aperture Radar (SAR) is a method for developing high... , textural...

148

E-Print Network 3.0 - aperture sequential beamforming Sample...  

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

solid objects Tadeusz Stepinski Summary: methods based on synthetic aperture concept (SAFT) is given and illustrated with experimental results... imaging, synthetic aperture,...

149

E-Print Network 3.0 - advanced synthetic aperture Sample Search...  

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

of Synthetic Aperture Summary: advanced synthetic aperture focusing tech- niques (SAFT) implemented in frequency domain have been widely... 1399 An Implementation of...

150

Seismicity and Reservoir Fracture Characterization  

Broader source: Energy.gov [DOE]

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

151

Motion Measurement for Synthetic Aperture Radar.  

SciTech Connect (OSTI)

Synthetic Aperture Radar (SAR) measures radar soundings from a set of locations typically along the flight path of a radar platform vehicle. Optimal focusing requires precise knowledge of the sounding source locations in 3 - D space with respect to the target scene. Even data driven focusing techniques (i.e. autofocus) requires some degree of initial fidelity in the measurements of the motion of the radar. These requirements may be quite stringent especially for fine resolution, long ranges, and low velocities. The principal instrument for measuring motion is typically an Inertial Measurement Unit (IMU), but these instruments have inherent limi ted precision and accuracy. The question is %22How good does an IMU need to be for a SAR across its performance space?%22 This report analytically relates IMU specifications to parametric requirements for SAR. - 4 - Acknowledgements Th e preparation of this report is the result of a n unfunded research and development activity . Although this report is an independent effort, it draws heavily from limited - release documentation generated under a CRADA with General Atomics - Aeronautical System, Inc. (GA - ASI), and under the Joint DoD/DOE Munitions Program Memorandum of Understanding. Sandia National Laboratories is a multi - program laboratory managed and operated by Sandia Corporation, a wholly owned subsidiary of Lockheed Martin Corporation, for the U.S. Department of En ergy's National Nuclear Security Administration under contract DE - AC04 - 94AL85000.

Doerry, Armin W.

2015-01-01T23:59:59.000Z

152

Suspensions in hydraulic fracturing  

SciTech Connect (OSTI)

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

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

1996-12-31T23:59:59.000Z

153

Deep borehole log evidence for fractal distribution of fractures in crystalline rock  

Science Journals Connector (OSTI)

......as well as large scale-lengths...fractures seen in drilling cores and...register on a borehole scanning...rock in the borehole wall. In...evidence in the drilling logs or retrieved...core that large-scale fractures...samples, and drilling history...control the large-scale trend...sensitive to borehole lithology......

Peter Leary

1991-12-01T23:59:59.000Z

154

Receiver for solar energy collector having improved aperture aspect  

DOE Patents [OSTI]

A secondary concentrator for use in receiver systems for linear focusing primary concentrators is provided with reflector wings at each end. The wings increase the capture of light rays reflected from areas adjacent the rim of a primary concentrator, increasing the apparent aperture size of the absorber as viewed from the rim of the primary concentrator. The length, tilt, and curvature of the wing reflectors can be adjusted to provide an absorber having a desired aperture aspect.

McIntire, William R. (Downers Grove, IL)

1984-01-01T23:59:59.000Z

155

Scaling Up – From Material Fracture Resistance to Fracture Representation in Welded Structures  

Science Journals Connector (OSTI)

Abstract This paper presents a procedure to integrate the material fracture resistance, quantified by the experimentally measured J-R curve, in the fracture representation of welded tubular joints. This method incorporates a validated ?-approach to estimate the elastic-plastic crack driving forces for fatigue cracks initiated at hot-spot locations of the welded tubular joints. The proposed scaling approach predicates on the fundamental assumption that the fracture resistance measured from the J-R curve, with a small and limited amount of crack extension, characterizes the material fracture resistance independent of the specimen geometry. The maximum crack extension allowed in the material testing standard marks the transferability limit of the material J-R curve to the welded joints. The extension of the fatigue crack in the welded joint leads to an increasing fracture resistance and a decreasing load resistance due to the increased crack area. The validation of this approach utilizes load-deformation responses from two scales of experimental specimens: 1) the large-scale welded tubular connection with a fatigue pre-crack; and 2) the large-scale frame test with predominantly fracture failure at the welded tubular joint. The load-deformation relationship based on the proposed scheme presents a close agreement with the experimentally recorded load-deformation behavior of the welded tubular joints. The proposed approach, when integrated into the push-over analyses of the large-scale tubular frames, presents an accurate estimation on the deformation level at which unstable fracture failure occurs and a conservative prediction of the corresponding failure load.

Xudong Qian; Yang Zhang; Ya Li

2014-01-01T23:59:59.000Z

156

On the fracture toughness of advanced materials  

E-Print Network [OSTI]

occurs when the materials resistance to fracture ceases toall classes of materials, the fracture resistance does notthese biological materials derive their fracture resistance

Launey, Maximilien E.

2009-01-01T23:59:59.000Z

157

Hydraulic Fracturing Poster | Department of Energy  

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

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

158

Self-potential observations during hydraulic fracturing  

E-Print Network [OSTI]

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

Moore, J R; Glaser, Steven D

2007-01-01T23:59:59.000Z

159

Geothermal Ultrasonic Fracture Imager | Department of Energy  

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

Geothermal Ultrasonic Fracture Imager Geothermal Ultrasonic Fracture Imager Development of a downhole wireline tool to characterize fractures in EGS wells in temperatures up to...

160

Ultrasound-Confirmed Frontal Bone Fracture  

E-Print Network [OSTI]

table--frontal sinus fractures. Facial Plast Surg Clin NorthConfirmed Frontal Bone Fracture Jeremy N. Johnson, DO Danielan isolated comminuted fracture of the left frontal sinus

Johnson, Jeremy N; Crandall, Stephen; Kang, Christopher S

2009-01-01T23:59:59.000Z

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


161

Fracture, aging and disease in bone  

E-Print Network [OSTI]

separate during bone fracture. Nature Materials 4, 612 (on nonagenarians with hip fractures? Injury 30, 169 (1999).bone mass as predictors of fracture in a prospective study.

Ager, J.W.; Balooch, G.; Ritchie, R.O.

2006-01-01T23:59:59.000Z

162

INVESTIGATION OF EFFICIENCY IMPROVEMENTS DURING CO2 INJECTION IN HYDRAULICALLY AND NATURALLY FRACTURED RESERVOIRS  

SciTech Connect (OSTI)

For many years many efforts have been performed in the laboratory experiments to duplicate the reservoir conditions. In this study, we will investigate the permeability change at different overburden conditions. The reduction in permeability with overburden pressure has been well known. Fatt and Davis (1952) presented the changes in permeability with pressure at range 0 to 15,000 psig and found that overburden pressure caused a reduction in permeability of the consolidated oil-bearing sandstone samples by as much as 50% at 10,000 psig. Wyble (1958) performed similar experiments on three different sandstone samples to determine the changes in conductivity, porosity and permeability at pressure range 0 to 5,000 psig. His results were consistent with the observation by Fatt and Davis (1952). During the experiments, different overburden pressures (radial force) were applied only to the cylinder core while the axial direction was kept at constant atmospheric pressure. Gray et al. (1963) enhanced the previous experiments by applying axial force and combining with overburden pressure (radial force) to measure the anisotropy permeability changes at more representative reservoir stress-state condition. They showed that permeability reduction subjected to overburden pressure as a function of the ratio of radial to axial stress and the permeability reduction under non-uniform stress (radial pressure {ne} axial pressure) is less than that under uniform stress. Although extensive work has been established on the effect of overburden pressure and stress-state on matrix permeability but there are some very interesting details of fractured rock behavior under stress that have not been investigated. In this study we will show the effect of fracture aperture and fracture permeability on the fluid flow under different overburden pressure. This study is a precursor to investigating fracture apertures under different stress-state conditions (confining stress, hydrostatic stress and triaxial stress) and imaging fracture aperture distributions using X-ray CT.

David S. Schechter

2002-04-01T23:59:59.000Z

163

Acid Fracture and Fracture Conductivity Study of Field Rock Samples  

E-Print Network [OSTI]

Acid fracturing is a well stimulation strategy designed to increase the productivity of a producing well. The parameters of acid fracturing and the effects of acid interaction on specific rock samples can be studied experimentally. Acid injection...

Underwood, Jarrod

2013-11-15T23:59:59.000Z

164

Investigation of Created Fracture Geometry through Hydraulic Fracture Treatment Analysis  

E-Print Network [OSTI]

Successful development of shale gas reservoirs is highly dependent on hydraulic fracture treatments. Many questions remain in regards to the geometry of the created fractures. Production data analysis from some shale gas wells quantifies a much...

Ahmed, Ibraheem 1987-

2012-11-30T23:59:59.000Z

165

TEMPORAL VARIATIONS OF FRACTURE DIRECTIONS AND FRACTURE DENSITIES IN THE  

Open Energy Info (EERE)

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

166

Hydrogen-Assisted Fracture: Materials Testing and Variables Governing Fracture  

E-Print Network [OSTI]

Hydrogen-Assisted Fracture: Materials Testing and Variables Governing Fracture Brian Somerday for producing both strength of materials and fracture mechanics data H H HH H H d/dt > 0 strength of materials: UTS, YS, f, RA H2 H2H2 H2 H2 H2 H2 H2 HH H H H H H H H H d/dt 0 fracture mechanics: KIH, KTH

167

Reservoir fracture characterizations from seismic scattered waves  

E-Print Network [OSTI]

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 ...

Fang, Xinding

2012-01-01T23:59:59.000Z

168

Fracture Conductivity of the Eagle Ford Shale  

E-Print Network [OSTI]

conductivity is influenced by several variables including fracture surface roughness, fracture closure stress, proppant size, and proppant concentration. The proppant concentration within a fracture can significantly affect the magnitude of fracture...

Guzek, James J

2014-07-25T23:59:59.000Z

169

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...

170

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...

171

Microearthquake Technology for EGS Fracture Characterization...  

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

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

172

Fluid Flow Modeling in Fractures  

E-Print Network [OSTI]

In this paper we study fluid flow in fractures using numerical simulation and address the challenging issue of hydraulic property characterization in fractures. The methodology is based on Computational Fluid Dynamics, ...

Sarkar, Sudipta

2004-01-01T23:59:59.000Z

173

Modeling Single Well Injection-Withdrawal (SWIW) Tests for Characterization of Complex Fracture-Matrix Systems  

SciTech Connect (OSTI)

The ability to reliably predict flow and transport in fractured porous rock is an essential condition for performance evaluation of geologic (underground) nuclear waste repositories. In this report, a suite of programs (TRIPOLY code) for calculating and analyzing flow and transport in two-dimensional fracture-matrix systems is used to model single-well injection-withdrawal (SWIW) tracer tests. The SWIW test, a tracer test using one well, is proposed as a useful means of collecting data for site characterization, as well as estimating parameters relevant to tracer diffusion and sorption. After some specific code adaptations, we numerically generated a complex fracture-matrix system for computation of steady-state flow and tracer advection and dispersion in the fracture network, along with solute exchange processes between the fractures and the porous matrix. We then conducted simulations for a hypothetical but workable SWIW test design and completed parameter sensitivity studies on three physical parameters of the rock matrix - namely porosity, diffusion coefficient, and retardation coefficient - in order to investigate their impact on the fracture-matrix solute exchange process. Hydraulic fracturing, or hydrofracking, is also modeled in this study, in two different ways: (1) by increasing the hydraulic aperture for flow in existing fractures and (2) by adding a new set of fractures to the field. The results of all these different tests are analyzed by studying the population of matrix blocks, the tracer spatial distribution, and the breakthrough curves (BTCs) obtained, while performing mass-balance checks and being careful to avoid some numerical mistakes that could occur. This study clearly demonstrates the importance of matrix effects in the solute transport process, with the sensitivity studies illustrating the increased importance of the matrix in providing a retardation mechanism for radionuclides as matrix porosity, diffusion coefficient, or retardation coefficient increase. Interestingly, model results before and after hydrofracking are insensitive to adding more fractures, while slightly more sensitive to aperture increase, making SWIW tests a possible means of discriminating between these two potential hydrofracking effects. Finally, we investigate the possibility of inferring relevant information regarding the fracture-matrix system physical parameters from the BTCs obtained during SWIW testing.

Cotte, F.P.; Doughty, C.; Birkholzer, J.

2010-11-01T23:59:59.000Z

174

FRACTURE STIMULATION IN ENHANCED GEOTHERMAL  

E-Print Network [OSTI]

FRACTURE STIMULATION IN ENHANCED GEOTHERMAL SYSTEMS A REPORT SUBMITTED TO THE DEPARTMENT OF ENERGY of stimulation is induced shear on preexisting fractures, which increases their transmissibility by orders of magnitude. The processes that create fractured rock are discussed from the perspective of geology and rock

Stanford University

175

Synthetic aperture integration (SAI) algorithm for SAR imaging  

DOE Patents [OSTI]

A method and system for detecting the presence of subsurface objects within a medium is provided. In some embodiments, the imaging and detection system operates in a multistatic mode to collect radar return signals generated by an array of transceiver antenna pairs that is positioned across the surface and that travels down the surface. The imaging and detection system pre-processes the return signal to suppress certain undesirable effects. The imaging and detection system then generates synthetic aperture radar images from real aperture radar images generated from the pre-processed return signal. The imaging and detection system then post-processes the synthetic aperture radar images to improve detection of subsurface objects. The imaging and detection system identifies peaks in the energy levels of the post-processed image frame, which indicates the presence of a subsurface object.

Chambers, David H; Mast, Jeffrey E; Paglieroni, David W; Beer, N. Reginald

2013-07-09T23:59:59.000Z

176

Simulation of fracture fluid cleanup and its effect on long-term recovery in tight gas reservoirs  

E-Print Network [OSTI]

technologies, such as large volume fracture treatments, are required before a reasonable profit can be made. Hydraulic fracturing is one of the best methods to stimulate a tight gas well. Most fracture treatments result in 3-6 fold increases in the productivity...

Wang, Yilin

2009-05-15T23:59:59.000Z

177

Fracture-resistant lanthanide scintillators  

DOE Patents [OSTI]

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.

Doty, F. Patrick (Livermore, CA)

2011-01-04T23:59:59.000Z

178

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

E-Print Network [OSTI]

modeling of faults and fractures: Geophysics, 60, 1514-1526.Poroelastic modeling of fracture-seismic wave interaction:by a heterogeneous fracture: J. Acoust. Soc. Am. , 115,

Nakagawa, S.

2010-01-01T23:59:59.000Z

179

Fracture Characterization in Enhanced Geothermal Systems by Wellbore...  

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

Nanosensors for Fractured Reservoir Characterization. 2. Characterization of Fracture Properties using Production Data. 3. Fracture Characterization by Resistivity...

180

Parallel optical nanolithography using nanoscale bowtie aperture array  

E-Print Network [OSTI]

-lithography. Our work employed a frequency-tripled diode-pumped solid state (DPSS) laser ( = 355 nm) and Shipley S1805 photoresist. An interference-based optical alignment system was employed to position the bowtie nano-apertures for near- field optical data storage," Jpn. J. Appl. Phys. 41(Part 1, No. 3B), 1632

Xu, Xianfan

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


181

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

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

Fractures in Engineered Geothermal Systems Project Objectives: Measure interwell fracture surface area and fracture spacing using sorbing tracers; measure fracture surface...

182

Fusion of sub-aperture overlapping areas based on wavelet transformation  

Science Journals Connector (OSTI)

A new sub-aperture overlapping area fusion algorithm based on wavelet transformation is proposed to retain high-frequency components as much as the measurements in the sub-aperture...

Chen, Yiwei; Sui, Yongxin; Yang, Huaijiang

2013-01-01T23:59:59.000Z

183

On eikonal distribution in the aperture of a two-mirror telescopic system  

Science Journals Connector (OSTI)

The derivation of the formula describing the eikonal distribution in the aperture of an axially symmetric two-mirror system with the source displaced from the ... of the eikonal in the aperture of a Schwarzschild

A. S. Venetskiy; V. A. Kaloshin

2012-09-01T23:59:59.000Z

184

E-Print Network 3.0 - antenna aperture fields Sample Search Results  

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

Engineering 5 Analysis of an H-shape Cross Slotted Aperture-Coupled Microstrip Patch Antenna Summary: Analysis of an H-shape Cross Slotted Aperture-Coupled Microstrip...

185

Arbitrarily-controllable programmable aperture light field cameras : design theory, and applications to image deconvolution & 3-dimensional scanning  

E-Print Network [OSTI]

This thesis describes a new class of programmable-aperture light field cameras based on an all-digital, grayscale aperture. A number of prototypes utilizing this arbitrarily-controllable programmable aperture (ACPA) light ...

Milnes, Thomas Bradford

2013-01-01T23:59:59.000Z

186

Procedure for estimating fracture energy from fracture surface roughness  

DOE Patents [OSTI]

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

Williford, Ralph E. (Kennewick, WA)

1989-01-01T23:59:59.000Z

187

Application of borehole geophysics to fracture identification and characterization in low porosity limestones and dolostones  

SciTech Connect (OSTI)

Geophysical logging was conducted in exploratory core holes drilled for geohydrological investigations at three sites used for waste disposal on the US Department of Energy's Oak Ridge Reservation. Geophysical log response was calibrated to borehole geology using the drill core. Subsequently, the logs were used to identify fractures and fractured zones and to characterize the hydrologic activity of such zones. Results of the study were used to identify zones of ground water movement and to select targets for subsequent piezometer and monitoring well installation. Neutron porosity, long- and short-normal resistivity, and density logs exhibit anomalies only adjacent to pervasively fractured zones and rarely exhibit anomalies adjacent to individual fractures, suggesting that such logs have insufficient resolution to detect individual fractures. Spontaneous potential, single point resistance, acoustic velocity, and acoustic variable density logs, however, typically exhibit anomalies adjacent to both individual fractures and fracture zones. Correlation is excellent between fracture density logs prepared from the examination of drill core and fractures identified by the analysis of a suite of geophysical logs that have differing spatial resolution characteristics. Results of the study demonstrate the importance of (1) calibrating geophysical log response to drill core from a site, and (2) running a comprehensive suite of geophysical logs that can evaluate both large- and small-scale rock features. Once geophysical log responses to site-specific geological features have been established, logs provide a means of identifying fracture zones and discriminating between hydrologically active and inactive fracture zones. 9 figs.

Haase, C.S.; King, H.L.

1986-01-01T23:59:59.000Z

188

FRACTURED PETROLEUM RESERVOIRS  

SciTech Connect (OSTI)

The four chapters that are described in this report cover a variety of subjects that not only give insight into the understanding of multiphase flow in fractured porous media, but they provide also major contribution towards the understanding of flow processes with in-situ phase formation. In the following, a summary of all the chapters will be provided. Chapter I addresses issues related to water injection in water-wet fractured porous media. There are two parts in this chapter. Part I covers extensive set of measurements for water injection in water-wet fractured porous media. Both single matrix block and multiple matrix blocks tests are covered. There are two major findings from these experiments: (1) co-current imbibition can be more efficient than counter-current imbibition due to lower residual oil saturation and higher oil mobility, and (2) tight fractured porous media can be more efficient than a permeable porous media when subjected to water injection. These findings are directly related to the type of tests one can perform in the laboratory and to decide on the fate of water injection in fractured reservoirs. Part II of Chapter I presents modeling of water injection in water-wet fractured media by modifying the Buckley-Leverett Theory. A major element of the new model is the multiplication of the transfer flux by the fractured saturation with a power of 1/2. This simple model can account for both co-current and counter-current imbibition and computationally it is very efficient. It can be orders of magnitude faster than a conventional dual-porosity model. Part II also presents the results of water injection tests in very tight rocks of some 0.01 md permeability. Oil recovery from water imbibition tests from such at tight rock can be as high as 25 percent. Chapter II discusses solution gas-drive for cold production from heavy-oil reservoirs. The impetus for this work is the study of new gas phase formation from in-situ process which can be significantly different from that of gas displacement processes. The work is of experimental nature and clarifies several misconceptions in the literature. Based on experimental results, it is established that the main reason for high efficiency of solution gas drive from heavy oil reservoirs is due to low gas mobility. Chapter III presents the concept of the alteration of porous media wettability from liquid-wetting to intermediate gas-wetting. The idea is novel and has not been introduced in the petroleum literature before. There are significant implications from such as proposal. The most direct application of intermediate gas wetting is wettability alteration around the wellbore. Such an alteration can significantly improve well deliverability in gas condensate reservoirs where gas well deliverability decreases below dewpoint pressure. Part I of Chapter III studies the effect of gravity, viscous forces, interfacial tension, and wettability on the critical condensate saturation and relative permeability of gas condensate systems. A simple phenomenological network model is used for this study, The theoretical results reveal that wettability significantly affects both the critical gas saturation and gas relative permeability. Gas relative permeability may increase ten times as contact angle is altered from 0{sup o} (strongly liquid wet) to 85{sup o} (intermediate gas-wetting). The results from the theoretical study motivated the experimental investigation described in Part II. In Part II we demonstrate that the wettability of porous media can be altered from liquid-wetting to gas-wetting. This part describes our attempt to find appropriate chemicals for wettability alteration of various substrates including rock matrix. Chapter IV provides a comprehensive treatment of molecular, pressure, and thermal diffusion and convection in porous media Basic theoretical analysis is presented using irreversible thermodynamics.

Abbas Firoozabadi

1999-06-11T23:59:59.000Z

189

Brittle Fracture Ductile to Brittle transition  

E-Print Network [OSTI]

FRACTURE Brittle Fracture Ductile to Brittle transition Fracture Mechanics T.L. Anderson CRC sulphur in steel Residual stress Continuity of the structure Microcracks #12;Fracture Brittle Ductile Factors affecting fracture Strain rate State of stress Temperature #12;Behaviour described Terms Used

Subramaniam, Anandh

190

Fracture characterization and discrimination criteria for karst and tectonic fractures in the Ellenburger Group, West Texas: Implications for reservoir and exploration models  

SciTech Connect (OSTI)

In the Ellenburger Group fractured dolomite reservoirs of West Texas, it is extremely difficult to distinguish between multiple phases of karst-related fracturing, modifications to the karst system during burial, and overprinting tectonic fractures. From the analyses of drill core, the authors developed criteria to distinguish between karst and tectonic fractures. In addition, they have applied these criteria within the context of a detailed diagenetic cement history that allows them to further refine the fracture genesis and chronology. In these analyses, the authors evaluated the relationships between fracture intensity, morphologic attributes, host lithology, fracture cement, and oil-staining. From this analysis, they have been able to characterize variations in Ellenburger tectonic fracture intensity by separating these fractures from karst-related features. In general, the majority of fracturing in the Ellenburger is caused by karst-related fracturing although a considerable percentage is caused by tectonism. These findings underscore the importance of considering the complete geologic evolution of a karst reservoir during exploration and field development programs. The authors have been able to more precisely define the spatial significance of the fracture data sets by use of oriented core from Andector Field. They have also demonstrated the importance of these results for exploration and reservoir development programs in West Texas, and the potential to extrapolate these results around the globe. Given the historic interest in the large hydrocarbon reserves in West Texas carbonate reservoirs, results of this study will have tremendous implications for exploration and production strategies targeting vuggy, fractured carbonate systems not only in West Texas, but throughout the globe.

Hoak, T.E. [Science Applications International Corp., Germantown, MD (United States); [Kestrel Geoscience, Littleton, CO (United States); Sundberg, K.R. [Phillips Petroleum Co., Bartlesville, OK (United States); Deyhim, P. [Oklahoma State Univ., Stillwater, OK (United States); Ortoleva, P. [Indiana Univ., Bloomington, IN (United States). Lab. for Computational Geodynamics

1998-12-31T23:59:59.000Z

191

Correlating toughness and roughness in ductile fracture  

E-Print Network [OSTI]

Three dimensional calculations of ductile crack growth under mode I plane strain, small scale yielding conditions are carried out using an elastic-viscoplastic constitutive relation for a progres- sively cavitating plastic solid with two populations of void nucleating second phase particles. Full field solutions are obtained for three dimensional material microstructures characterized by ran- dom distributions of void nucleating particles. Crack growth resistance curves and fracture surface roughness statistics are calculated using standard procedures. The range of void nucleating particle volume fractions considered give rise to values of toughness, JIC, that vary by a factor of four. For all volume fractions considered, the computed fracture surfaces are self-affine over a size range of about two orders of magnitude with a roughness exponent of 0.54 $\\pm$ 0.03. For small void nucleating particle volume fractions, the mean large particle spacing serves as a single dominant length scale. In this regime, the c...

Ponson, Laurent; Osovski, Shmulik; Bouchaud, Elisabeth; Tvergaard, Viggo; Needleman, Alan

2013-01-01T23:59:59.000Z

192

NETL Releases Hydraulic Fracturing Study  

Broader source: Energy.gov [DOE]

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

193

Fracture model for cemented aggregates  

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

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.

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

194

Complications in Ankle Fracture Surgery.  

E-Print Network [OSTI]

??Mikko Ovaska. Complications in Ankle Fracture Surgery. Helsinki Bone and Joint Research Group, Department of Orthopaedic Surgery and Traumatology, Faculty of Medicine, University of Helsinki,… (more)

Ovaska, Mikko

2014-01-01T23:59:59.000Z

195

Seismic anisotropy of fractured rock  

E-Print Network [OSTI]

A comparison of the theory with recent ultra- sonic experiments on a simulated fractured medium .... Note that Poisson's ratio and Young's modulus for the.

M. Schoenberg, C. M. Sayers

2000-02-18T23:59:59.000Z

196

Expanding Coherent Array Processing to Larger Apertures Using Empirical Matched Field Processing  

SciTech Connect (OSTI)

We have adapted matched field processing, a method developed in underwater acoustics to detect and locate targets, to classify transient seismic signals arising from mining explosions. Matched field processing, as we apply it, is an empirical technique, using observations of historic events to calibrate the amplitude and phase structure of wavefields incident upon an array aperture for particular repeating sources. The objective of this project is to determine how broadly applicable the method is and to understand the phenomena that control its performance. We obtained our original results in distinguishing events from ten mines in the Khibiny and Olenegorsk mining districts of the Kola Peninsula, for which we had exceptional ground truth information. In a cross-validation test, some 98.2% of 549 explosions were correctly classified by originating mine using just the Pn observations (2.5-12.5 Hz) on the ARCES array at ranges from 350-410 kilometers. These results were achieved despite the fact that the mines are as closely spaced as 3 kilometers. Such classification performance is significantly better than predicted by the Rayleigh limit. Scattering phenomena account for the increased resolution, as we make clear in an analysis of the information carrying capacity of Pn under two alternative propagation scenarios: free-space propagation and propagation with realistic (actually measured) spatial covariance structure. The increase in information capacity over a wide band is captured by the matched field calibrations and used to separate explosions from very closely-spaced sources. In part, the improvement occurs because the calibrations enable coherent processing at frequencies above those normally considered coherent. We are investigating whether similar results can be expected in different regions, with apertures of increasing scale and for diffuse seismicity. We verified similar performance with the closely-spaced Zapolyarni mines, though discovered that it may be necessary to divide event populations from a single mine into identifiable subpopulations. For this purpose, we perform cluster analysis using matched field statistics calculated on pairs of individual events as a distance metric. In our initial work, calibrations were derived from ensembles of events ranging in number to more than 100. We are considering the performance now of matched field calibrations derived with many fewer events (even, as mentioned, individual events). Since these are high-variance estimates, we are testing the use of cross-channel, multitaper, spectral estimation methods to reduce the variance of calibrations and detection statistics derived from single-event observations. To test the applicability of the technique in a different tectonic region, we have obtained four years of continuous data from 4 Kazakh arrays and are extracting large numbers of event segments. Our initial results using 132 mining explosions recorded by the Makanchi array are similar to those obtained in the European Arctic. Matched field processing clearly separates the explosions from three closely-spaced mines located approximately 400 kilometers from the array, again using waveforms in a band (6-10 Hz) normally considered incoherent for this array. Having reproduced ARCES-type performance with another small aperture array, we have two additional objectives for matched field processing. We will attempt to extend matched field processing to larger apertures: a 200 km aperture (the KNET) and, if data permit, to an aperture comprised of several Kazakh arrays. We also will investigate the potential of developing matched field processing to roughly locate and classify natural seismicity, which is more diffuse than the concentrated sources of mining explosions that we have investigated to date.

Ringdal, F; Harris, D B; Kvaerna, T; Gibbons, S J

2009-07-23T23:59:59.000Z

197

GEOLOGY AND FRACTURE SYSTEM AT STRIPA  

E-Print Network [OSTI]

1978. An Approach to the Fracture Hydrology at Stripa:Shanley. 1972. Analysis of Fracture Orientations for InputHydraulic Pro erties of Fractures by P. A. Witherspoon, C.

Olkiewicz, O.

2010-01-01T23:59:59.000Z

198

PNP - a new class of coded aperture arrays  

SciTech Connect (OSTI)

The authors report on a new class of coded aperture arrays which has all the desirable imaging characteristics of the Uniformly Redundant Array (URA), yet is constructible in dimensions which are forbidden to that design. In addition, the new arrays (called PNP arrays, for Pseudo-Noise Product) are of self-supporting geometry, simplifying fabrication and making them ideal candidates for situations where active collimators are employed, as for example in high-energy ..gamma..-ray imaging. A unique and important feature of all PNP arrays is the ability to produce reconstructed images whose noise is uniform regardless of the original source structure. A comparison of the predicted performance of the PNP, URA, GEOMETRIC, and PINHOLE designs is presented. Coded aperture imaging, which utilizes position-sensitive detectors, was first proposed as a means for detecting x-ray and gamma sources.

Gottesman, S.R.; Schneid, E.J.

1986-02-01T23:59:59.000Z

199

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

SciTech Connect (OSTI)

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.

Liu, H.H.; Rutqvist, J.

2009-10-01T23:59:59.000Z

200

Analysis of fractures in volcanic cores from Pahute Mesa, Nevada Test Site  

SciTech Connect (OSTI)

The Nevada Test Site (NTS), located in Nye County, southern Nevada, was the location of 828 announced underground nuclear tests, conducted between 1951 and 1992. Approximately one-third of these tests were detonated near or below the water table. An unavoidable consequence of these testing activities was introducing radionuclides into the subsurface environment, impacting groundwater. Groundwater flows beneath the NTS almost exclusively through interconnected natural fractures in carbonate and volcanic rocks. Information about these fractures is necessary to determine hydrologic parameters for future Corrective Action Unit (CAU)-specific flow and transport models which will be used to support risk assessment calculations for the U.S. Department of Energy, Nevada Operations Office (DOE/NV) Underground Test Area (UGTA) remedial investigation. Fracture data are critical in reducing the uncertainty of the predictive capabilities of CAU-specific models because of their usefulness in generating hydraulic conductivity values and dispersion characteristics used in transport modeling. Specifically, fracture aperture and density (spacing) are needed to calculate the permeability anisotropy of the formations. Fracture mineralogy information is used qualitatively to evaluate diffusion and radionuclide retardation potential in transport modeling. All these data can best be collected through examination of core samples.

Drellack, S.L. Jr.; Prothro, L.B.; Roberson, K.E. [and others

1997-09-01T23:59:59.000Z

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


201

Alignment and Aperture Scan at the Fermilab Booster  

SciTech Connect (OSTI)

The Fermilab Booster is currently in the process of an intensity upgrade referred to as the Proton Improvement Plan (PIP). The goal of PIP is to have the Booster provide a proton beam flux of 2 x 10{sup 17} protons/hour. This is almost double the current operation of 1.1 x 10{sup 17} protons/hour. Beam losses in the machine due to the increased flux will create larger integrated doses on aperture limiting components that will need to be mitigated. The Booster accelerates beam from 400 MeV to 8 GeV at a rep rate of 15hz and then extracts beam to the Main Injector. Several percent of the beam is lost within 3 msec after injection in the early part of acceleration. The aperture at injection energy was recently measured using corrector scans. Along with magnet survey data and aperture scan data a plan to realign the magnets in the Booster was developed and implemented in May 2012. The beam studies, analysis of the scan and alignment data, and the result of the magnet moves are presented.

Seiya, K.; Lackey, J.; Marsh, W.; Pellico, W.; Still, D.; Triplet, K.; Waller, A.; /Fermilab

2012-05-01T23:59:59.000Z

202

Microearthquake Technology for EGS Fracture Characterization  

Broader source: Energy.gov [DOE]

Project objectives: To understand how EGS fracture networks develop; To develop technology to determine accurate absolute three-dimensional positions of EGS fracture networks.

203

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...

204

Fracture Processes Observed with A Cryogenic Detector  

E-Print Network [OSTI]

In the early stages of running of the CRESST dark matter search using sapphire detectors at very low temperature, an unexpectedly high rate of signal pulses appeared. Their origin was finally traced to fracture events in the sapphire due to the very tight clamping of the detectors. During extensive runs the energy and time of each event was recorded, providing large data sets for such phenomena. We believe this is the first time the energy release in fracture has been directly and accurately measured on a microscopic event-by-event basis. The energy threshold corresponds to the breaking of only a few hundred covalent bonds, a sensitivity some orders of magnitude greater than that of previous technique. We report some features of the data, including energy distributions, waiting time distributions, autocorrelations and the Hurst exponent. The energy distribution appear to follow a power law, $dN/dE\\propto E^{-\\beta}$, similar to the power law for earthquake magnitudes, and after appropriate translation, with a similar exponent. In the time domain,the waiting time $w$ or gap distribution between events has a power law behavior at small $w$ and an exponential fall-off at large $w,$ and can be fit $\\propto w^{-\\alpha}e^{-w/w_0}$. The autocorrelation function shows time correlations lasting for substantial parts of an hour. An asymmetry is found around large events, with higher count rates after, as opposed to before,the large event .

J. Astrom; P. C. F. Di Stefano; F. Proebst; L. Stodolsky; J. Timonen; C. Bucci; S. Cooper; C. Cozzini; F. v. Feilitzsch; H. Kraus; J. Marchese; O. Meier; U. Nagel; Y. Ramachers; W. Seidel; M. Sisti; S. Uchaikin; L. Zerle

2006-03-21T23:59:59.000Z

205

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

SciTech Connect (OSTI)

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.

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

1997-08-01T23:59:59.000Z

206

Migration of Water Pulse Through Fractured Porous Media  

SciTech Connect (OSTI)

Contaminant transport from waste-disposal sites is strongly affected by the presence of fractures and the degree of fracture-matrix interaction. Characterization of potential contaminant plumes at such sites is difficult, both experimentally and numerically. Simulations of water flow through fractured rock were performed to examine the penetration depth of a large pulse of water entering such a system. Construction water traced with lithium bromide was released during the excavation of a tunnel at Yucca Mountain, Nevada, which is located in an unsaturated fractured tuff formation. Modeling of construction-water migration is qualitatively compared with bromide-to-chloride (Br/CI) ratio data for pore-water salts extracted from drillcores. The influences of local heterogeneities in the fracture network and variations in hydrogeologic parameters were examined by sensitivity analyses and Monte Carlo simulations. The simulation results are qualitatively consistent with the observed Br/CI signals, although these data may only indicate a minimum penetration depth, and water may have migrated further through the fracture network.

S. Finsterle; J. T. Fabryka-Martin; J. S. Y. Wang

2001-06-06T23:59:59.000Z

207

UK Oil and Gas Collaborative Doctoral Training Centre (2014 start) Project Title: Coupled flow of water and gas during hydraulic fracture in shale (EARTH-15-CM1)  

E-Print Network [OSTI]

of water and gas during hydraulic fracture in shale (EARTH-15-CM1) Host institution: University of Oxford in extracting gas from these low-permeability rocks is hydraulic fracture. This involves injecting large of water and gas during hydraulic fracturing and subsequent gas recovery. This is essential in order

Henderson, Gideon

208

Fracture and Healing of Rock Salt Related to Salt Caverns  

SciTech Connect (OSTI)

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.

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

1999-03-01T23:59:59.000Z

209

Fracturing Fluid Characterization Facility  

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

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

210

SPALL FRACTURE AND SPALL FRACTURE AND COMPACTION COMPACTION  

National Nuclear Security Administration (NNSA)

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

211

Statistical Properties of Fracture Precursors  

Science Journals Connector (OSTI)

We present the data of a mode-I fracture experiment. The samples are broken under imposed pressure. The acoustic emission of microfractures before the breakup of the sample is registered. From the acoustic signals, the position of microfractures and the energy released are calculated. A measure of the clustering of microfractures yields information about the critical load. The statistics from energy measurements strongly suggest that the fracture can be viewed as a critical phenomenon; energy events are distributed in magnitude as a power law, and a critical exponent is found for the energy near fracture.

A. Garcimartín; A. Guarino; L. Bellon; S. Ciliberto

1997-10-27T23:59:59.000Z

212

Fracture of synthetic diamond M. D. Droty  

E-Print Network [OSTI]

Fracture of synthetic diamond M. D. Droty Ctystallume, 3506 Bassett Street, Santa Clara, California 1995) The fracture behavior of synthetic diamond has been investigated using indentation methods and by the tensile testing of pre-notched fracture-mechanics type samples. Specifically, the fracture toughness

Ritchie, Robert

213

Water Use for Hydraulic Fracturing: A Texas Sized Problem?  

E-Print Network [OSTI]

The state of Texas could face a 2.7 trillion gallon shortfall of water by 2060. Hydraulic fracturing (HF) requires large amounts of water for each well. Tax incentives should be offered to companies that substitute brackish groundwater for fresh...

LeClere, David

214

Microstructure-Properties: IMicrostructure-Properties: I Lecture 6A: FractureLecture 6A: Fracture  

E-Print Network [OSTI]

-Properties: IMicrostructure-Properties: I Lecture 6A: FractureLecture 6A: Fracture 27-301 Fall, 2007 Prof. A. D. Rollett the fracture resistance of materials to their microstructure. · Both ceramics and metals exhibit strongly microstructure dependent fracture resistance. · This section focuses on basic theory of brittle fracture

Rollett, Anthony D.

215

Critical Fracture Stress and Fracture Strain Models for the Prediction of Lower and  

E-Print Network [OSTI]

Critical Fracture Stress and Fracture Strain Models for the Prediction of Lower and Upper Shelf fracture stress and stress modified fracture strain models are utilized to describe the variation of lower and upper shelf fracture toughness with temperature and strain rate for two alloy steels used

Ritchie, Robert

216

Journal of Biomechanics 38 (2005) 15171525 Fracture in human cortical bone: local fracture criteria and  

E-Print Network [OSTI]

Journal of Biomechanics 38 (2005) 1517­1525 Fracture in human cortical bone: local fracture, Livermore, CA 94550 Accepted 19 July 2004 Abstract Micromechanical models for fracture initiation such micromechanical models have been developed for the fracture of bone. In fact, although the fracture event

Ritchie, Robert O.

217

Risk assessment of groundwater contamination from hydraulic fracturing fluid spills in Pennsylvania  

E-Print Network [OSTI]

Fast-paced growth in natural gas production in the Marcellus Shale has fueled intense debate over the risk of groundwater contamination from hydraulic fracturing and the shale gas extraction process at large. While several ...

Fletcher, Sarah Marie

2012-01-01T23:59:59.000Z

218

Design of thick aperture for fine-resolution neutron penumbral imaging  

SciTech Connect (OSTI)

Compact sources of 14-MeV neutrons have been imaged with a penumbral-coded aperture at a two-point resolution of 80{mu}m. We desire to improve the penumbral-aperture microscope to obtain resolutions as fine as 10{mu}m. In penumbral-coded-aperture imaging, the resolution is ultimately limited by the sharpness of the aperture point-spread function. I present a design for a thick penumbral aperture that provides the desired sharpness over a field of view of 150{mu}m. The point-spread function of these apertures is sufficiently isoplanatic and distortion-free to allow linear reconstruction of complex source distributions. The designs is generally appropriate for similar imaging techniques, such as fine-resolution neutron or gamma-ray pinhole imaging. 5 refs., 5 figs.

Ress, D.

1989-10-19T23:59:59.000Z

219

Temporary Sealing of Fractures | Open Energy Information  

Open Energy Info (EERE)

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

220

Sensitivity analysis of fracture scattering  

E-Print Network [OSTI]

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, ...

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

2010-01-01T23:59:59.000Z

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


221

Environmental Impacts of Hydraulic Fracturing  

Science Journals Connector (OSTI)

...their environmental impacts, which has been published...the hydrogeological impacts of oil and gas development...Chafin, 1994), not fracking. Watson and Bachu...Frontiers Ecology Environment. 2011. 9( 9): 503...R. Environmental Impacts of Hydraulic Fracturing...

Richard Jackson

222

Fracture of aluminum naval structures  

E-Print Network [OSTI]

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

Galanis, Konstantinos, 1970-

2007-01-01T23:59:59.000Z

223

Numerical simulation of hydraulic fracturing  

E-Print Network [OSTI]

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...: Petroleum Engineering NUMERICAL SIMULATION OF HYDRAULIC FRACTURING A Thesis by JOSEPH BARNES WARNER Approved as to style and content by: S. A. Holditch (Chairman of Committee) D. D. Van Fleet (member) J. E. Russell (m be ) W. D. Von onten ( ead...

Warner, Joseph Barnes

2012-06-07T23:59:59.000Z

224

A comparison of spotlight synthetic aperture radar image formation techniques  

SciTech Connect (OSTI)

Spotlight synthetic aperture radar images can be formed from the complex phase history data using two main techniques: (1) polar-to-cartesian interpolation followed by two-dimensional inverse Fourier transform (2DFFT), and (2) convolution backprojection (CBP). CBP has been widely used to reconstruct medical images in computer aided tomography, and only recently has been applied to form synthetic aperture radar imagery. It is alleged that CBP yields higher quality images because (1) all the Fourier data are used and (2) the polar formatted data is used directly to form a 2D Cartesian image and therefore 2D interpolation is not required. This report compares the quality of images formed by CBP and several modified versions of the 2DFFT method. We show from an image quality point of view that CBP is equivalent to first windowing the phase history data and then interpolating to an exscribed rectangle. From a mathematical perspective, we should expect this conclusion since the same Fourier data are used to form the SAR image. We next address the issue of parallel implementation of each algorithm. We dispute previous claims that CBP is more readily parallelizable than the 2DFFT method. Our conclusions are supported by comparing execution times between massively parallel implementations of both algorithms, showing that both experience similar decreases in computation time, but that CBP takes significantly longer to form an image.

Knittle, C.D.; Doren, N.E.; Jakowatz, C.V.

1996-10-01T23:59:59.000Z

225

A cost optimized small aperture 2 in 1 VLHC  

SciTech Connect (OSTI)

The costing algorithm used here was started at the time of the SSC proposal, was updated and presented at the Port Jefferson VLHC meeting in october 2000, and has been slightly modified again for this study. The method starts from a specified central field and aperture, and uses approximate formulae to design the dipole magnet cross sections. The required masses of superconductor, stabilizing copper, support stainless steel, and yoke are calculated, and the surface area of the cold mass determined. Costs per unit weight, or area/temperature, are assigned for each item and a linear cost added to cover the tunnel, supports, magnet ends, correctors, quadrupoles, survey etc. The unit costs were originally extracted from the SSC estimates, but have been inflated and modified since. They have no Intersection Point magnets, detectors, detector halls, EDIA, contingency, R and D or escalation. The assumed linear cost, including magnet ends, with the inflation factor, is 22 k$/m. If the aperture is small, as in the pipeatron, the magnets can be long, end costs reduced, and the packing factor improved. This expectation is confirmed by the recent Fermilab VLHC study. Using the total estimate from this study, the algorithm has been modified to include these effects.

R. B. Palmer; B. Parker; G. W. Foster

2002-11-19T23:59:59.000Z

226

Aperture-averaged level-crossing probability in an atmospheric communication link  

Science Journals Connector (OSTI)

The intensity statistics of light pulses in an atmospheric communication link are studied here for the case of a finite (nonpoint) detector aperture. The calculation of the statistics...

Last, I; Azar, Z; Azoulay, E; Tur, M

1988-01-01T23:59:59.000Z

227

E-Print Network 3.0 - aperture uvoir space Sample Search Results  

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

Computer Technologies and Information Sciences 52 Quantum Coherence in a Superfluid Josephson Junction Supradeep Narayana and Yuki Sato Summary: of 75 75 60 nm apertures...

228

E-Print Network 3.0 - aluminum oxide aperture Sample Search Results  

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

Search Powered by Explorit Topic List Advanced Search Sample search results for: aluminum oxide aperture Page: << < 1 2 3 4 5 > >> 1 EFFECTS OF INTERFERENCE AND OXIDATION ON...

229

E-Print Network 3.0 - aperture radar image Sample Search Results  

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

flight trajecto- In synthetic aperture radar (SAR) imaging a scene... -y(s). The projection data and reconstructed ... Source: Yazici, Birsen - Department of Electrical,...

230

E-Print Network 3.0 - aperture tabletop soft Sample Search Results  

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

of IEEE Conference on Computer Vision and Pattern Recognition... Light Fields and Coded Aperture Refocusing, in proceedings of ACM SIGGRAPH 2007 (ACM Transactions... - denheimer,...

231

E-Print Network 3.0 - apertures ii theoretical Sample Search...  

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

IEEE TRANSACTIONS ON GEOSCIENCE AND REMOTE SENSING, VOL. 39, NO. 2, FEBRUARY 2001 291 Image Reconstruction and Enhanced Resolution Summary: imposed by the aperture function nulls...

232

E-Print Network 3.0 - aperture synthesis observations Sample...  

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

Canarias Collection: Physics 77 Image and Depth from a Conventional Camera with a Coded Aperture Anat Levin Rob Fergus Fredo Durand William T. Freeman Summary: Image and Depth...

233

Comparison of Discrete Fracture and Effective Media Representation of Fractures on Azimuthal AVO  

E-Print Network [OSTI]

In fractured reservoir development, azimuthal AVO (AVOaz) properties of reflected PP waves from reservoir tops are often used to infer fracture properties. The fracture parameter inversion is based on either an effective ...

Zhang, Yang

2005-01-01T23:59:59.000Z

234

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

E-Print Network [OSTI]

Fluid flow process in fractured reservoirs is controlled primarily by the connectivity of fractures. The presence of fractures in these reservoirs significantly affects the mechanism of fluid flow. They have led to problems in the reservoir which...

Ogbechie, Joachim Nwabunwanne

2012-02-14T23:59:59.000Z

235

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

E-Print Network [OSTI]

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 ...

Bakku, Sudhish Kumar

2011-01-01T23:59:59.000Z

236

A 16-m Telescope for the Advanced Technology Large Aperture Telescope (ATLAST) Mission  

E-Print Network [OSTI]

for the telescope and its instruments. Solar array panels, an antenna and a solar sail are also folded up against compartment which is attached to a spacecraft bus which provides power, attitude control and communications and is separated from the launch vehicle, its solar arrays and high gain antenna will be deployed

Sirianni, Marco

237

Characterization of subsurface fracture patterns in the Coso geothermal  

Open Energy Info (EERE)

subsurface fracture patterns in the Coso geothermal subsurface fracture patterns in the Coso geothermal reservoir by analyzing shear-wave splitting of microearthquake seismorgrams Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Conference Proceedings: Characterization of subsurface fracture patterns in the Coso geothermal reservoir by analyzing shear-wave splitting of microearthquake seismorgrams Details Activities (1) Areas (1) Regions (0) Abstract: A large number of microearthquake seismograms have been recorded by a downhole, three-component seismic network deployed around the Coso, California geothermal reservoir. Shear-wave splitting induced by the alignment of cracks in the reservoir has been widely observed in the recordings. Over 100 events with body wave magnitude greater than 1.0 from

238

INTERPRETATION OF A HYDRAULIC FRACTURING EXPERIMENT, MONTICELLO, SOUTH CAROLINA  

E-Print Network [OSTI]

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

Narasimhan, T.N.

2014-01-01T23:59:59.000Z

239

Analysis Of Macroscopic Fractures In Granite In The Hdr Geothermal...  

Open Energy Info (EERE)

between core and acoustic borehole imagery. Detailed structural analysis of the fracture population indicates that fractures are grouped in two principal fractures sets...

240

Fracture Evolution Following a Hydraulic Stimulation within an...  

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

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

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


241

Aging and Fracture of Human Cortical Bone and Tooth Dentin  

E-Print Network [OSTI]

Mechanistic aspects of fracture and R-curve behavior inof failure of solid biomaterials and bone: `fracture' and `pre- fracture' toughness. Materials Science and Engineering:

Ager III, Joel W.

2008-01-01T23:59:59.000Z

242

Poroelastic modeling of seismic boundary conditions across a fracture  

E-Print Network [OSTI]

on poroelasticity of fractures. Both authors would like toYork. Figure 3: For a high permeability fracture, the fluidpressure across the fracture is continuous, which can be

Schoenberg, M.A.; Nakagawa, S.

2006-01-01T23:59:59.000Z

243

DNAPL invasion into a partially saturated dead-end fracture  

E-Print Network [OSTI]

Mobilization in Rock Fractures, Water Resources Research,of DNAPL trapped in dead-end fractures, Geophysical Researchpartially saturated dead-end fracture and a DNAPL lens above

Su, Grace W.; Javandel, Iraj

2008-01-01T23:59:59.000Z

244

Updated fracture incidence rates for the US version of FRAX®  

E-Print Network [OSTI]

presenting with non-vertebral fractures. Osteoporos Int 18:2006) Epidemiology of vertebral fractures: implications forORIGINAL ARTICLE Updated fracture incidence rates for the US

Ettinger, B.; Black, D. M.; Dawson-Hughes, B.; Pressman, A. R.; Melton, L. J.

2010-01-01T23:59:59.000Z

245

Transphyseal Fracture of the Distal Humerus in a Neonate  

E-Print Network [OSTI]

M edicine Transphyseal Fracture of the Distal Humerus in aalignment without osseous fracture and a moderate joint2] revealed a transverse fracture through the distal left

Baker, Annalee M; Methratta, Sosamma T.; Choudhary, Arabinda K

2011-01-01T23:59:59.000Z

246

Dynamics of DNAPL penetration into fractured porous media  

SciTech Connect (OSTI)

Dense nonaqueous phase liquids (DNAPLs) that pool above stratigraphic contacts as a result of capillary forces can migrate downward through fractures in the underlying fine-grained layer. Although the DNAPL in the fracture is excluded from the surrounding porous matrix by capillary forces, the DNAPL constituent will dissolve and migrate by diffusion into the matrix. As a front of moderately soluble DNAPL advances into a fracture, the flux of dissolved material into the matrix increases until it becomes comparable to the rate of flow into the fracture, reducing the pressure in the DNAPL phase and slowing its advance. If the DNAPL front encounters a constriction with sufficiently large entry pressure, its advance will halt temporarily. But as the concentration gradients driving diffusion into the matrix decrease, there will be less DNAPL lost by diffusion and the DNAPL pressure at the constriction will increase until it exceeds the entry pressure, causing the downward advance of the front to suddenly resume. Because the time scales of diffusion are much slower than those of density flow, this analysis suggests that under certain circumstances a DNAPL can suddenly resume its downward advance after a long period of apparent immobility. In one plausible example, a dichloromethane front passes through 5 m of fractured clay in 16 days, is immobile for more than four years, and then suddenly moves again. Where this phenomenon is possible, removal of DNAPL to protect underlying aquifers becomes more important as a remediation goal.

Ross, B. [Disposal Safety Inc., Washington, DC (United States); Lu, N. [Colorado School of Mines, Golden, CO (United States). Div. of Engineering

1999-01-01T23:59:59.000Z

247

Fracture opening/propagation behavior and their significance on pressure-time records during hydraulic fracturing  

SciTech Connect (OSTI)

Hydraulic fracturing with constant fluid injection rate was numerically modeled for a pair of rectangular longitudinal fractures intersecting a wellbore in an impermeable rock mass, and numerical calculations have been performed to investigate the relations among the form of pressure-time curves, fracture opening/propagation behavior and permeability of the mechanically closed fractures. The results have shown that both permeability of the fractures and fluid injection rate significantly influence the form of the pressure-time relations on the early stage of fracture opening. Furthermore it has been shown that wellbore pressure during fracture propagation is affected by the pre-existing fracture length.

Takashi Kojima; Yasuhiko Nakagawa; Koji Matsuki; Toshiyuki Hashida

1992-01-01T23:59:59.000Z

248

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

E-Print Network [OSTI]

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

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

2000-01-01T23:59:59.000Z

249

Hydrogen-Assisted Fracture: Materials Testing and Variables Governing Fracture  

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

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

250

Monitoring hydraulic fracture growth: Laboratory experiments  

SciTech Connect (OSTI)

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

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

2000-04-01T23:59:59.000Z

251

Inverse-synthetic-aperture imaging of trees over a ground plane  

SciTech Connect (OSTI)

Recent data collections with the Sandia VHF-UHF synthetic-aperture radar have yielded surprising results; trees appear brighter in the images than expected! In an effort to understand this phenomenon, various small trees have been measured on the Sandia folded compact range with the inverse-synthetic-aperture imaging system. A compilation of these measurements is contained in this report.

Zittel, D.H.; Brock, B.C.; Littlejohn, J.H.; Patitz, W.E.

1995-11-01T23:59:59.000Z

252

Numerical aperture influence on 3-D multi-layer optical data storage systems , Edwin P. Walkera  

E-Print Network [OSTI]

Numerical aperture influence on 3-D multi-layer optical data storage systems Yi Zhanga* , Edwin P storage system is analyzed. Keywords: NA, multi-layer data storage, two-photon recording, capacity) 550-0596, Fax: (858) 550-0917 #12;Numerical aperture influence on 3-D multi-layer optical data storage

Esener, Sadik C.

253

Analysis of an H-shape Cross Slotted Aperture-Coupled Microstrip Patch Antenna  

E-Print Network [OSTI]

Analysis of an H-shape Cross Slotted Aperture-Coupled Microstrip Patch Antenna Chae-Hyun Jung #1 circuit model for an H-shape cross slotted aperture-coupled microstrip patch antenna (ACMPA) are presented to design the antenna. The ACMPA consists of three conductor layers such as patch, ground plane, and feed

Myung, Noh-Hoon

254

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

E-Print Network [OSTI]

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...

Kim, Tae Hyung

2009-05-15T23:59:59.000Z

255

Integrated 3D Acid Fracturing Model for Carbonate Reservoir Stimulation  

E-Print Network [OSTI]

in integrating fracture propagation, acid transport and dissolution, and well performance models in a seamless fashion for acid fracturing design. In this new approach, the fracture geometry data of a hydraulic fracture is first obtained from commercial models...

Wu, Xi

2014-06-23T23:59:59.000Z

256

VALIDATION OF MASSIVELY PARALLEL SIMULATIONS OF DYNAMIC FRACTURE AND  

E-Print Network [OSTI]

VALIDATION OF MASSIVELY PARALLEL SIMULATIONS OF DYNAMIC FRACTURE AND FRAGMENTATION OF BRITTLE element simulations of dynamic fracture and fragmentation of brittle solids are presented. Fracture the results of massively parallel numerical simulations of dynamic fracture and fragmentation in brittle

Barr, Al

257

Hydraulic-fracture growth in dipping anisotropic strata as viewed through the surface deformation field  

SciTech Connect (OSTI)

In 1983 and 1984 Oak Rdige National Laboratory conducted a series of precision ground deformation measurements before, during, and after the generation of several large hydraulic fractures in a dipping member of the Cambrian Conasauga Shale. Each fracture was produced by the injection of approximately 500,000 L of slurry on a single day. Injection depth was 300 m. Leveling surveys were run several days before and several days after the injections. An array of eight high-precision borehole tiltmeters monitored ground deformations continuously for a period of several weeks. Analysis of the leveling and the tilt measurements revealed surface uplifts as great as 25 mm and tilts of tens of microradians during each injection. Furthermore, partial recovery (subsidence) of the ground took place during the days following an injection, accompanied by shifts in the position of maximum resultant uplift. Interpretation of the tilt measurements is consistent with stable widening and extension of hydraulic fractures with subhorizontal orientations. Comparison of the measured tilt patterns with fracture orientations established from logging of observation wells suggests that shearing parallel to the fracture planes accompanied fracture dilation. This interpretation is supported by measured tilts and ground uplifts that were as much as 100 percent greater than those expected from fracture dilation alone. Models of elastically anisotropic overburden rock do not explain the measured tilt patterns in the absence of shear stresses in the fracture planes. This work represents the first large-scale hydraulic-fracturing experiment in which the possible effects of material anisotropy and fracture-parallel shears have been measured and interpreted.

Holzhausen, G.R.; Haase, C.S.; Stow, S.H.; Gazonas, G.

1985-01-01T23:59:59.000Z

258

Hydraulic Fracturing | Open Energy Information  

Open Energy Info (EERE)

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

259

Method for directional hydraulic fracturing  

DOE Patents [OSTI]

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

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

1994-01-01T23:59:59.000Z

260

Fractured: Experts examine the contentious issue of hydraulic fracturing water use  

E-Print Network [OSTI]

shale rock, releasing oil and gas from the rock. Combined with the use of horizontal drilling, fracturing has unlocked large deposits of oil and gas and opened up new oil and gas #30;elds in areas around the country. #31;e majority of hydraulic... years. ?Now what we have found in the last #30;ve or #28;#25; years is that source rocks are still loaded with oil and gas,? he said. Source rocks are usually organic-rich shales in which petroleum forms. ?#31;e energy industry has never had...

Wythe, Kathy

2013-01-01T23:59:59.000Z

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


261

Nonplanar fracture propagation from a horizontal wellbore: Experimental study  

SciTech Connect (OSTI)

This paper presents experimental results related to hydraulic fracturing of a horizontal well, specifically the nonplanar fracture geometries resulting from fracture initiation and propagation. Experiments were designed to investigate nonplanar fracture geometries. This paper discusses how these nonplanar fractures can be responsible for premature screenout and excessive treatment pressure when a horizontal well is hydraulically fractured. Reasons for unsuccessful hydraulic fracturing treatments of a horizontal well are presented and recommendations to ensure clear communication channels between the wellbore and the fracture are given.

Abass, H.H.; Hedayati, S.; Meadows, D.L.

1996-08-01T23:59:59.000Z

262

Tracer Methods for Characterizing Fracture Stimulation in Engineered...  

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

Tracer Methods for Characterizing Fracture Stimulation in Engineered Geothermal Systems (EGS) Tracer Methods for Characterizing Fracture Stimulation in Engineered Geothermal...

263

Fracture, aging and disease in bone  

E-Print Network [OSTI]

by enhancing the materials resistance to microstructuralgrowth resistance of microcracking brittle materials. J. Am.resistance to fracture of the Page 4 Fracture, Aging and Disease in Bone underlying material.

Ager, J.W.; Balooch, G.; Ritchie, R.O.

2006-01-01T23:59:59.000Z

264

Modeling of Acid Fracturing in Carbonate Reservoirs  

E-Print Network [OSTI]

The acid fracturing process is a thermal, hydraulic, mechanical, and geochemical (THMG)-coupled phenomena in which the behavior of these variables are interrelated. To model the flow behavior of an acid into a fracture, mass and momentum balance...

Al Jawad, Murtada s

2014-06-05T23:59:59.000Z

265

Acoustic Character Of Hydraulic Fractures In Granite  

E-Print Network [OSTI]

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

Paillet, Frederick I.

1983-01-01T23:59:59.000Z

266

Statistical Modeling of Fracture Toughness Data.  

E-Print Network [OSTI]

??The fracture toughness of the zirconium alloy (Zr-2.5Nb) is an important parameter in determining the flaw tolerance for operation of pressure tubes in reactor. Fracture… (more)

Prakash, Guru

2007-01-01T23:59:59.000Z

267

EA-1810: Finding of No Significant Impact | Department of Energy  

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

locate large aperture fractures (LAFs) and to drill two (2) production diameter geothermal wells on BLM administered Public lands in the San Emidio resource area. The innovative...

268

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

E-Print Network [OSTI]

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

Lu, Zhiming

269

A model of fracture nucleation, growth and arrest, and consequences for fracture density and scaling  

E-Print Network [OSTI]

A model of fracture nucleation, growth and arrest, and consequences for fracture density; accepted 1 February 2013; published 25 April 2013. [1] In order to improve discrete fracture network (DFN a new DFN modeling based on the evolution of fracture network formation--nucleation, growth, and arrest

Boyer, Edmond

270

FEM Analysis ofFEM Analysis of Deformation and Fracture ofDeformation and Fracture of  

E-Print Network [OSTI]

FEM Analysis ofFEM Analysis of Deformation and Fracture ofDeformation and Fracture of Deformation and Fracture in Polycrystalline -TiAl + 2-Ti3Al Single Crystals #12;Use of -TiAl + 2-Ti3Al Alloys-Temperature Ductility ·Low Ambient-Temperature Fracture Toughness (KIC

Grujicic, Mica

271

Statistical fracture modeling: crack path and fracture criteria with application to homogeneous and  

E-Print Network [OSTI]

Statistical fracture modeling: crack path and fracture criteria with application to homogeneous; accepted 23 January 2002 Abstract Analysis has been performed on fracture initiation near a crack in a brittle material with strength described by Weibull statistics. This nonlocal fracture model allows

Ritchie, Robert

272

A Membrane Deflection Fracture Experiment to Investigate Fracture Toughness of Freestanding MEMS Materials  

E-Print Network [OSTI]

A Membrane Deflection Fracture Experiment to Investigate Fracture Toughness of Freestanding MEMS Materials H.D. Espinosa* and B. Peng ABSTRACT This paper presents a novel Membrane Deflection Fracture Experiment (MDFE) to investigate the fracture toughness of MEMS and other advanced materials in thin film

Espinosa, Horacio D.

273

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

SciTech Connect (OSTI)

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

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

2006-05-15T23:59:59.000Z

274

Acoustic-emission monitoring during hydraulic fracturing  

SciTech Connect (OSTI)

This paper reports that microseismic events or acoustic emissions associated with hydraulic fracturing are recorded with a borehole seismic tool in a deviated well during multirate injection, shut-in, and flowback. The event locations indicate that fracture orientation, length, and height are compatible with regional stress directions and estimates of the fracture size that are based on pressure decline.

Stewart, L. (Schlumberger-Doll Research (US)); Cassell, B.R. (Schlumberger Wireline Services (US)); Bol, G.M. (Nederlanse Aardolie Mij. B.V. (NL))

1992-06-01T23:59:59.000Z

275

Hydraulic Fracturing in Michigan Integrated Assessment  

E-Print Network [OSTI]

Hydraulic Fracturing in Michigan Integrated Assessment #12;Agenda · Welcome and introduction and timeline · Panel presentation and discussion · Facilitated Q & A · Closing remarks #12;Hydraulic Fracturing · Leverages resources IA BENEFITS Benefits of Integrated Assessment #12;Key Points: · Hydraulic Fracturing (HF

Kamat, Vineet R.

276

Hydraulic Fracture: multiscale processes and moving  

E-Print Network [OSTI]

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

Peirce, Anthony

277

Regulation of Hydraulic Fracturing in California  

E-Print Network [OSTI]

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

Kammen, Daniel M.

278

Hydraulic Fracture: multiscale processes and moving  

E-Print Network [OSTI]

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

Peirce, Anthony

279

Challenges in Continuum Modelling of Intergranular Fracture  

E-Print Network [OSTI]

Challenges in Continuum Modelling of Intergranular Fracture V. R. Coffman*, J. P. Sethna , A. R-2501, USA Cornell Fracture Group, Rhodes Hall, Cornell University, Ithaca, NY 14853-2501, USA § Department fracture in polycrystals is often simulated by finite elements coupled to a cohesive zone model

Sethna, James P.

280

FRACTURE IN DISORDERED BRITTLE MEDIA A Dissertation  

E-Print Network [OSTI]

FRACTURE IN DISORDERED BRITTLE MEDIA A Dissertation Presented to the Faculty of the Graduate School by Ashivni Shekhawat May 2013 #12;c 2013 Ashivni Shekhawat ALL RIGHTS RESERVED #12;FRACTURE IN DISORDERED- lem of brittle fracture in disordered media. Chapters 2 and 4 are concerned with various aspects

Sethna, James P.

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


281

FRACTURE TOUGHNESS OF WOOD AND WOOD COMPOSITES  

E-Print Network [OSTI]

FRACTURE TOUGHNESS OF WOOD AND WOOD COMPOSITES DURING CRACK PROPAGATION Noah Matsumoto Structural, USA * Corresponding author: John.Nairn@oregonstate.edu SWST member #12;Fracture Toughness of Wood and Wood Composites During Crack Propagation ABSTRACT The mode I fracture toughness as a function of crack

Nairn, John A.

282

Models for MetaVCeramic Interface Fracture  

E-Print Network [OSTI]

ChaDter 12 Models for MetaVCeramic Interface Fracture ZHIGANG SUO C. FONG SHIH Metal shortcomingthat haslimited their wide- spread use-their tendency to fracture easily. In many systems, the low on interface fracture are reviewed in this chapter. With few exceptions, attention is limited to continuum

Suo, Zhigang

283

Interferometric hydrofracture microseism localization using neighboring fracture  

E-Print Network [OSTI]

Interferometric hydrofracture microseism localization using neighboring fracture Oleg V. Poliannikov1 , Alison E. Malcolm1 , Hugues Djikpesse2 , and Michael Prange2 ABSTRACT Hydraulic fracturing is the process of injecting high-pressure fluids into a reservoir to induce fractures and thus improve reservoir

Malcolm, Alison

284

Introduction That fracture is governed by processes  

E-Print Network [OSTI]

Introduction That fracture is governed by processes occurring over a wide range of length scales has been recognized since the earli- est developments of modern fracture me- chanics. Griffith's study by several decades the first at- tempts to apply atomistically grounded traction-separation laws to fracture

Beltz, Glenn E.

285

LA-13194-MS Fracture Characterization of the  

E-Print Network [OSTI]

LA-13194-MS Fracture Characterization of the Bandelier Tuff in OU-1098 (TA-2 and TA-41) LosN A T I technical correctness. #12;Fracture Characterization of the Bandelier Tuff in OU-1098 (TA-2 and TA-41 Los Alamos, New Mexico 87545 #12;1 Fracture Characterization of the Bandelier Tuff in OU-1098 (TA-2

286

Sizing of a hot dry rock reservoir from a hydraulic fracturing experiment  

SciTech Connect (OSTI)

Hot dry rock (HDR) reservoirs do not lend themselves to the standard methods of reservoir sizing developed in the petroleum industry such as the buildup/drawdown test. In a HDR reservoir the reservoir is created by the injection of fluid. This process of hydraulic fracturing of the reservoir rock usually involves injection of a large volume (5 million gallons) at high rates (40BPM). A methodology is presented for sizing the HDR reservoir created during the hydraulic fracturing process. The reservoir created during a recent fracturing experiment is sized using the techniques presented. This reservoir is then investigated for commercial potential by simulation of long term power production. 5 refs., 7 figs.

Zyvoloski, G.

1985-01-01T23:59:59.000Z

287

Capillary fracture of soft gels  

E-Print Network [OSTI]

A liquid droplet resting on a soft gel substrate can deform that substrate to the point of material failure, whereby fractures develop on the gel surface that propagate outwards from the contact-line in a starburst pattern. In this paper, we characterize i) the initiation process in which the number of arms in the starburst is controlled by the ratio of surface tension contrast to the gel's elastic modulus and ii) the propagation dynamics showing that once fractures are initiated they propagate with a universal power law $L\\propto t^{3/4}$. We develop a model for crack initiation by treating the gel as a linear elastic solid and computing the deformations within the substrate from the liquid/solid wetting forces. The elastic solution shows that both the location and magnitude of the wetting forces are critical in providing a quantitative prediction for the number of fractures and, hence, an interpretation of the initiation of capillary fractures. This solution also reveals that the depth of the gel is an impo...

Bostwick, Joshua B

2013-01-01T23:59:59.000Z

288

Relative Permeability of Fractured Rock  

E-Print Network [OSTI]

, and by the Department of Petroleum Engineering, Stanford University Stanford Geothermal Program Interdisciplinary Research in Engineering and Earth Sciences STANFORD UNIVERSITY Stanford, California #12;#12;v Abstract fractures and various fluids have yielded different relative permeability-saturation relations. This study

Stanford University

289

Hydraulic fracture stimulation treatment of Well Baca 23. Geothermal Reservoir Well-Stimulation Program  

SciTech Connect (OSTI)

Well Stimulation Experiment No. 5 of the Geothermal Reservoir Well Stimulation Program (GRWSP) was performed on March 22, 1981 in Baca 23, located in Union's Redondo Creek Project Area in Sandoval County, New Mexico. The treatment selected was a large hydraulic fracture job designed specifically for, and utilizing frac materials chosen for, the high temperature geothermal environment. The well selection, fracture treatment, experiment evaluation, and summary of the job costs are presented herein.

Not Available

1981-06-01T23:59:59.000Z

290

Geomechanical Simulation of Fluid-Driven Fractures  

SciTech Connect (OSTI)

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

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

2012-11-30T23:59:59.000Z

291

CONSTRAINT EFFECT IN FRACTURE WHAT IS IT  

SciTech Connect (OSTI)

The meaning of the phrase 'constraint effect in fracture' has changed in the past two decades from 'contained plasticity' to a broader description of 'dependence of fracture toughness value on geometry of test specimen or structure'. This paper will first elucidate the fundamental mechanics reasons for the apparent 'constraint effects in fracture', followed by outlining a straightforward approach to overcoming this problem in both brittle (elastic) and ductile (elastic-plastic) fracture. It is concluded by discussing the major difference in constraint effect on fracture event in elastic and elastic-plastic materials.

Lam, P; Prof. Yuh J. Chao, P

2008-10-29T23:59:59.000Z

292

Structural Settings Of Hydrothermal Outflow- Fracture Permeability  

Open Energy Info (EERE)

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

293

Sensitivity and uncertainty analyses applied to one-dimensional radionuclide transport in a layered fractured rock: MULTFRAC --Analytic solutions and local sensitivities; Phase 2, Iterative performance assessment: Volume 1  

SciTech Connect (OSTI)

Exact analytical solutions based on the Laplace transforms are derived for describing the one-dimensional space-time-dependent, advective transport of a decaying species in a layered, saturated rock system intersected by a planar fracture of varying aperture. These solutions, which account for advection in fracture, molecular diffusion into the rock matrix, adsorption in both fracture and matrix, and radioactive decay, predict the concentrations in both fracture and rock matrix and the cumulative mass in the fracture. The solute migration domain in both fracture and rock is assumed to be semi-infinite with non-zero initial conditions. The concentration of each nuclide at the source is allowed to decay either continuously or according to some periodical fluctuations where both are subjected to either a step or band release mode. Two numerical examples related to the transport of Np-237 and Cm-245 in a five-layered system of fractured rock were used to verify these solutions with several well established evaluation methods of Laplace inversion integrals in the real and complex domain. In addition, with respect to the model parameters, a comparison of the analytically derived local sensitivities for the concentration and cumulative mass of Np-237 in the fracture with the ones obtained through a finite-difference method of approximation is also reported.

Gureghian, A.B.; Wu, Y.T.; Sagar, B. [Southwest Research Inst., San Antonio, TX (United States). Center for Nuclear Waste Regulatory Analyses; Codell, R.A. [Nuclear Regulatory Commission, Washington, DC (United States)

1992-12-01T23:59:59.000Z

294

Lynx: A High-Resolution Synthetic Aperture Radar  

SciTech Connect (OSTI)

Lynx is a high resolution, synthetic aperture radar (SAR) that has been designed and built by Sandia National Laboratories in collaboration with General Atomics (GA). Although Lynx may be operated on a wide variety of manned and unmanned platforms, it is primarily intended to be fielded on unmanned aerial vehicles. In particular, it may be operated on the Predator, I-GNAT, or Prowler II platforms manufactured by GA Aeronautical Systems, Inc. The Lynx production weight is less than 120 lb. and has a slant range of 30 km (in 4 mm/hr rain). It has operator selectable resolution and is capable of 0.1 m resolution in spotlight mode and 0.3 m resolution in stripmap mode. In ground moving target indicator mode, the minimum detectable velocity is 6 knots with a minimum target cross-section of 10 dBsm. In coherent change detection mode, Lynx makes registered, complex image comparisons either of 0.1 m resolution (minimum) spotlight images or of 0.3 m resolution (minimum) strip images. The Lynx user interface features a view manager that allows it to pan and zoom like a video camera. Lynx was developed under corporate finding from GA and will be manufactured by GA for both military and commercial applications. The Lynx system architecture will be presented and some of its unique features will be described. Imagery at the finest resolutions in both spotlight and strip modes have been obtained and will also be presented.

Doerry, A.W.; Hensley, W.H.; Pace, F.; Stence, J.; Tsunoda, S.I.; Walker, B.C.; Woodring, M.

1999-03-08T23:59:59.000Z

295

The emerging technology of synthetic aperture focusing for ultrasonic testing  

SciTech Connect (OSTI)

The capabilities of synthetic aperture focusing techniques for ultrasonic testing (SAFT-UT) as a nondestructure testing technique are presented. SAFT-UT is a digital ultrasonic imaging method, which can be adapted to many different materials, specimen geometries, and wave propagation modes. The process allows each point within the inspected volume to be focused upon by mathematically simulating the action of a lens, specifically formed for imaging that point in the volume. All points are therefore imaged at the maximum available resolution. The PNL effort in SAFT-UT is a continuation of a program started earlier by the NRC at the University of Michigan. The objectives of the present program are: (1) to engineer and evaluate a real-time flaw detection and imaging system based on SAFT-UT for inservice inspection of all required LWR components, (2) to establish calibration and field test procedures, (3) to demonstrate and validate the system through field reactor inspections, and (4) to gain ASME Code acceptance of the real-time SAFT-UT technique. The following aspects of SAFT-UT are presented in this paper: (1) brief overview of SAFT imaging theory, (2) results demonstrating achievable lateral resolution, and (3) presentation of shear wave SAFT-UT images.

Busse, L.J.; Collins, H.D.; Doctor, S.R.

1984-06-01T23:59:59.000Z

296

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

SciTech Connect (OSTI)

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.

R. L. Billingsley; V. Kuuskraa

2006-03-31T23:59:59.000Z

297

Microseismic Tracer Particles for Hydraulic Fracturing  

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

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

298

Experience proves forced fracture closure works  

SciTech Connect (OSTI)

Forced closure, or perhaps better-named ``reverse gravel packing,`` of fractures immediately following hydraulic fracturing with proppant and gelled fluids is a technique which, with rare exception, can be extremely beneficial to the success of almost every hydraulic fracture treatment. By proper planning of the rig-up to allow immediate flow-back, substantial quantities of polymer and load fluid can be removed while simultaneously negating undesirable proppant settling within fractures in the near wellbore area. Fracture smearing (dilution of proppant into an extending fracture) after shutdown can be negated. And in most cases, proppant production from the formation can be reduced. Discussions in the article explain why Ely and Associates has the confidence to make these claims after extensive hydraulic fracturing experience in many geographical areas.

Ely, J.W. [John Ely and Associates, Inc., Houston, TX (United States)

1996-01-01T23:59:59.000Z

299

Interaction between Injection Points during Hydraulic Fracturing  

E-Print Network [OSTI]

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

Hals, Kjetil M D

2012-01-01T23:59:59.000Z

300

Tensile Fracture of Welded Polymer Interfaces: Miscibility, Entanglements and Crazing  

E-Print Network [OSTI]

Large-scale molecular simulations are performed to investigate tensile failure of polymer interfaces as a function of welding time $t$. Changes in the tensile stress, mode of failure and interfacial fracture energy $G_I$ are correlated to changes in the interfacial entanglements as determined from Primitive Path Analysis. Bulk polymers fail through craze formation, followed by craze breakdown through chain scission. At small $t$ welded interfaces are not strong enough to support craze formation and fail at small strains through chain pullout at the interface. Once chains have formed an average of about one entanglement across the interface, a stable craze is formed throughout the sample. The failure stress of the craze rises with welding time and the mode of craze breakdown changes from chain pullout to chain scission as the interface approaches bulk strength. The interfacial fracture energy $G_I$ is calculated by coupling the simulation results to a continuum fracture mechanics model. As in experiment, $G_I$ increases as $t^{1/2}$ before saturating at the average bulk fracture energy $G_b$. As in previous simulations of shear strength, saturation coincides with the recovery of the bulk entanglement density. Before saturation, $G_I$ is proportional to the areal density of interfacial entanglements. Immiscibiltiy limits interdiffusion and thus suppresses entanglements at the interface. Even small degrees of immisciblity reduce interfacial entanglements enough that failure occurs by chain pullout and $G_I \\ll G_b$.

Ting Ge; Gary S. Grest; Mark O. Robbins

2014-10-07T23:59:59.000Z

Note: This page contains sample records for the topic "large aperture fractures" from the National Library of EnergyBeta (NLEBeta).
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301

SNM neutron detection using a time-gated synthetic aperture hybrid approach  

SciTech Connect (OSTI)

This work focuses on using forward and adjoint transport in a hybrid application of 3-D deterministic (PENTRAN) and Monte Carlo (MCNP5) codes to model a series of neutron detector blocks. These blocks, or 'channels, ' contain a unique set of moderators with 4 atm He-3 detectors tuned to detect and profile a gross energy spectrum of a passing neutron (SNM) source. Ganging the units together as a large area system enables one to apply time gating the source-detector response to maximize signal to noise responses from a passing source with minimal background; multiple units may be positioned as a collective synthetic aperture detector array to be used as a way of performing real time neutron spectroscopy for detecting special nuclear materials in moving vehicles. The initial design, detector response coupling, confirmation of initial design functionality using adjoint transport calculations, and realistic simulation using PENTRAN and MCNP5 are presented. Future work will include optimization and application to realistic scenarios and additional sources. (authors)

Molinar, M.; Yi, C.; Edgar, C. A.; Manalo, K.; Chin, M.; Sjoden, G. [Nuclear and Radiological Engineering Program, George W. Woodruff School of Mechanical Engineering, Georgia Institute of Technology, 770 State Street, Atlanta GA 30332-0745 (United States)

2013-07-01T23:59:59.000Z

302

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

E-Print Network [OSTI]

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

Wang, J.S.Y.

2013-01-01T23:59:59.000Z

303

Numerical modeling of time-lapse seismic data from fractured reservoirs including fluid flow and geochemical processes  

E-Print Network [OSTI]

Discrete Fracture Network (DFN) models. My seismic simulation study suggests that CO2 saturated reservoir shows approximately ten times more attenuation than brine saturated reservoir. Similarly, large P-wave velocity variation in CO2 saturated reservoir...

Shekhar, Ravi

2009-05-15T23:59:59.000Z

304

E-Print Network 3.0 - apertures Sample Search Results  

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

Sato Summary: in which we take an array of nanoscale apertures that form a superfluid 4He Josephson junction and apply... quantum phase gradients directly along the array. We...

305

E-Print Network 3.0 - aperture grb observatory Sample Search...  

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

Collection: Mathematics 8 arXiv:astro-ph9711245v120Nov1997 To be published in "Gamma-Ray Bursts, 4th Huntsville Symposium", 1998, ed. Summary: aperture to the APT, but has a...

306

Video rate spectral imaging using a coded aperture snapshot spectral imager  

Science Journals Connector (OSTI)

We have previously reported on coded aperture snapshot spectral imagers (CASSI) that can capture a full frame spectral image in a snapshot. Here we describe the use of CASSI for...

Wagadarikar, Ashwin A; Pitsianis, Nikos P; Sun, Xiaobai; Brady, David J

2009-01-01T23:59:59.000Z

307

E-Print Network 3.0 - aperture based imrt Sample Search Results  

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

the values of EUD were calculated. (3) Simulation of IMRT... is the direct aperture optimization (DAO) method. The IMRT plans generated by DAO can be delivered within 10 min......

308

Colloid migration in fractured media  

SciTech Connect (OSTI)

Field studies at the Nevada Test Site by researchers at Lawrence Livermore National Laboratory have demonstrated that radionuclides are being transported by colloidal material suspended in groundwater. This observation is counter to most predictions from contaminant transport models because the models assume adsorbed species are immobile. The purpose of this research is to quantify the transport processes for colloidal materials and develop the mechanistic understanding necessary to predict radionuclide transport in fractured media. There were three areas of investigation during this year that have addressed these issues: chemical control of colloid deposition on clean mineral surfaces, colloid accumulation on fracture surfaces, and the influence of deposited colloids on colloid and tracer migration. 7 refs.

Hunt, J.R. (California Univ., Berkeley, CA (USA). Dept. of Civil Engineering)

1989-09-15T23:59:59.000Z

309

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

E-Print Network [OSTI]

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

Nelson, J.T.

2009-01-01T23:59:59.000Z

310

Results of a 1995 hydraulic fracturing survey and a comparison of 1995 and 1990 industry practices  

SciTech Connect (OSTI)

This paper presents the results of a hydraulic fracturing survey conducted in 1995 on behalf of the Gas Research institute (GRI). The purpose of the survey was to determine the types of formations that are normally fracture treated; gather data on the fracture treatments that are normally pumped; determine the level of data collection being conducted in the field; determine the level of data analysis being conducted in the office and the field; solicit opinions on the level of technology required to obtain an accurate analysis for fracture treatments; solicit opinions of the limitations of current technology; determine what costs operators could justify to analyze fracture treatment data and obtain ideas on new areas of research. Data gathered in the survey included respondents company size (major, large/small independent, service company or consultant), geographical area of operation, well depths and permeabilities, fracture treatment size, proppant type and volume, level of detail in data gathering, fracture treatment design and real-time analysis. The 1995 data were compared to a similar survey conducted in 1990 by GRI to determine technology trends.

Carter, R.H.; Holditch, S.A.; Wolhart, S.L.

1996-12-31T23:59:59.000Z

311

Fracture of irradiated zircaloy-2  

Science Journals Connector (OSTI)

This paper summarizes the results of a series of investigations to evaluate the fracture behavior of Zircaloy-2 as influenced by BWR and PWR conditions. The results show that the response of the fracture toughness of Zircaloy-2 to various combinations of cold work, hydrogen content and neutron fluence in hot pressurized water is characterized by embrittlement to a point where saturation in the fracture toughness is attained. Further in-reactor exposure beyond this saturation point appears to have no effect on toughness although other mechanical properties such as flow stress continue to change. In addition, anisotropy in the toughness of rolled plate material, evident in the unirradiated condition, is retained during in-reactor exposure and after increases in hydrogen content. Several processes are thought to be contributing to the toughness of Zircaloy-2 during irradiation. The reduction in toughness at low exposures must result from defect interactions with the deformation modes and the formation of the brittle hydride phase. However, the occurrence of saturation is not explained by these mechanisms in view of data on other mechanical properties and corrosion rates. It is suggested that the difference in the conditions for initiation of slip and twinning would indicate that the twinning component of deformation is not reduced by irradiation damage as much as the slip component. Saturation is, therefore, interprétable on the basis that twinning plays a major role in the crack tip plastic zone after irradiation. Additional study of the importance of twinning in determining the toughness of Zircaloy-2 was attempted by examining the relationship between texture and the anisotropy in fracture toughness. A correlation is shown to exist between the crack tip shear stresses resolved on the 1121 twin system and the toughness anisotropy.

R.G. Hoagland; R.G. Rowe

1969-01-01T23:59:59.000Z

312

Thermal single-well injection-withdrawal tracer tests for determining fracture-matrix heat transfer area  

SciTech Connect (OSTI)

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).

Pruess, K.; Doughty, C.

2010-01-15T23:59:59.000Z

313

Localized rotation of principal stress around faults and fractures determined from borehole breakouts in hole B of the Taiwan Chelungpu-fault Drilling Project (TCDP)  

Science Journals Connector (OSTI)

To reveal details of stress perturbations associated with faults and fractures, we investigated the faults and large fractures accompanied by stress-induced borehole breakouts or drilling-induced tensile fractures in hole B of the Taiwan Chelungpu-fault Drilling Project (TCDP). Then, we determined the relationship between the faults and fractures and stress orientation changes. We identified faults and fractures from electrical images of the borehole wall obtained by downhole logging but also from photographs and descriptions of retrieved core samples, and measured the variations in the principal horizontal stress orientation ascertained from borehole breakouts observed on the electrical images in the vicinity of the faults and fractures. Identification of geological structures (faults, fractures, and lithologic boundaries) by electrical images only is difficult and may sometimes yield incorrect results. In a novel approach, therefore, we used both the electrical images and core photographs to identify geological structures. We found four patterns of stress orientation change, or no change, in the vicinity of faults and fractures in TCDP hole B: (i) abrupt (discontinuous) rotation in the vicinity of faults or fractures; (ii) gradual rotation; (iii) suppression of breakouts at faults, fractures, or lithologic boundaries; and (iv) no change in the stress orientation. We recognized stress fluctuations, that is, heterogeneous mesoscale (? 10 cm) stress distributions with respect to both stress orientation and magnitude. In addition, we found that stress state changes occurred frequently in the vicinity of faults, fractures, and lithologic boundaries.

Weiren Lin; En-Chao Yeh; Jih-Hao Hung; Bezalel Haimson; Tetsuro Hirono

2010-01-01T23:59:59.000Z

314

Fractured gas reservoirs in the Devonian shale of the Illinois and Appalachian basins  

SciTech Connect (OSTI)

The Devonian and Lower Mississippian black shale sequence of Kentucky includes the New Albany Shale of Illinois basin and the Ohio Shale of the Appalachian basin. Fractured reservoirs in the Ohio Shale contain a major gas resource, but have not been so prolific in the New Albany Shale. The authors propose two models of fractured shale reservoirs in both the Illinois and the Appalachian basins, to be tested with gas production data. (1) Where reactivated basement faults have propagated to the surface, the lack of an effective seal has prevented the development of overpressure. The resulting fracture system is entirely tectonic is origin, and served mainly as a conduit for gas migration from the basin to the surface. Gas accumulations in such reservoirs typically are small and underpressured. (2) Where basement faults have been reactivated but have not reached the surface, a seal on the fractured reservoir is preserved. In areas where thermal maturity has been adequate, overpressuring due to gas generation resulted in a major extension of the fracture system, as well as enhanced gas compression and adsorption. Such gas accumulations are relatively large. Original overpressuring has been largely lost, due both to natural depletion and to uncontrolled production. The relative thermal immaturity of the Illinois basin accounts for the scarcity of the second type of fractured reservoir and the small magnitude of the New Albany Shale gas resource.

Hamilton-Smith, T.; Walker, D.; Nuttall, B. (Kentucky Geological Survey, Lexington (United States))

1991-08-01T23:59:59.000Z

315

Fracture-enhanced porosity and permeability trends in Bakken Formation, Williston basin, western North Dakota  

SciTech Connect (OSTI)

Fractures play a critical role in oil production from the Bakken Formation (Devonian and Mississippian) in the North Dakota portion of the Williston basin. The Bakken Formation in the study area is known for its low matrix porosity and permeability, high organic content, thermal maturity, and relative lateral homogeneity. Core analysis has shown the effective porosity and permeability development within the Bakken Formation to be related primarily to fracturing. In theory, lineaments mapped on the surface reflect the geometry of basement blocks and the zones of fracturing propagated upward from them. Fracturing in the Williston basin is thought to have occurred along reactivated basement-block boundaries in response to varying tectonic stresses and crustal flexure throughout the Phanerozoic. Landsat-derived lineament maps were examined for the area between 47/degrees/ and 48/degrees/ north lat. and 103/degrees/ and 104/degrees/ west long. (northern Billings and Golden Valley Counties, and western McKenzie County, North Dakota) in an attempt to identify large-scale fracture trends. In the absence of major tectonic deformation in the craton, a subtle pattern of fracturing has propagated upward through the sedimentary cover and emerged as linear topographic features visible on these large-scale, remote-sensed images.

Freisatz, W.B.

1988-07-01T23:59:59.000Z

316

Apparatus and method for monitoring underground fracturing  

DOE Patents [OSTI]

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

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

1999-08-10T23:59:59.000Z

317

Apparatus and method for monitoring underground fracturing  

DOE Patents [OSTI]

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

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

318

Optimization of fractured well performance of horizontal gas wells  

E-Print Network [OSTI]

................................................24 3.4 Ideal Number of Transverse Fractures..........................................26 3.5 Constant Volume Transverse Fractures ........................................32 3.6... of a longitudinal fracture..............................................10 2.5 Example of horizontal well with longitudinal fracture performance .............11 2.6 DVS representation of transverse fractures...

Magalhaes, Fellipe Vieira

2009-06-02T23:59:59.000Z

319

Fracture induced anisotropy in viscoelastic UNLP, 11 Octubre de 2012  

E-Print Network [OSTI]

Fracture induced anisotropy in viscoelastic media UNLP, 11 Octubre de 2012 . Fracture induced anisotropy in viscoelastic media ­ p. #12;Fractured media. I Fractures are common in the earth's crust due to different factors, for instance, tectonic stresses and natural or artificial hydraulic fracturing caused

Santos, Juan

320

Transitionaltensile fracture propagation: a status report T. Engelder  

E-Print Network [OSTI]

Abstract One model for the development of hybrid shear fractures is transitional±tensile fracture that is the hybrid of a joint and a shear fracture. Crack±seal veins with oblique ®bers are possible candidates of a spectrum of brittle fracture types, and that some fractures are a hybrid of both end members (cf. Hancock

Engelder, Terry

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


321

Application of zircaloy deformation and fracture maps to predicting dry spent fuel storage conditions  

SciTech Connect (OSTI)

The research reported details the development of theoretical deformation and fracture maps for Zircaloy at temperatures between 50 and 850/sup 0/C and for stresses between 5 and 500 MPa. The maps predict behavior which is in agreement with a large number of experimental observations reported in the literature. Transformations in deformation and fracture mechanisms, creep rate magnitudes, and times to fracture are predicted from the maps. Results are reported for grain sizes of 5 ..mu..m. The deformation and fracture maps are altered for irradiation effects based upon high stress-high temperature, short time, postirradiation data. Maximum allowable temperature limits to achieve 40 years dry storage are calculated as a function of time spent in wet pool storage using a decaying cask temperature function and a life fraction rule. 122 references, 15 figures, 4 tables.

Chin, G.A.; Madsen, N.H.; Khan, M.A.

1983-08-01T23:59:59.000Z

322

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

E-Print Network [OSTI]

INVESTIGATION OF THE EFFECT OF GEL RESIDUE ON HYDRAULIC FRACTURE CONDUCTIVITY USING DYNAMIC FRACTURE CONDUCTIVITY TEST A Thesis by FIVMAN MARPAUNG Submitted to the Office of Graduate Studies of Texas A&M University in partial... fulfillment of the requirements for the degree of MASTER OF SCIENCE December 2007 Major Subject: Petroleum Engineering INVESTIGATION OF THE EFFECT OF GEL RESIDUE ON HYDRAULIC FRACTURE CONDUCTIVITY USING DYNAMIC FRACTURE CONDUCTIVITY TEST A...

Marpaung, Fivman

2008-10-10T23:59:59.000Z

323

Effects of fracturing fluid recovery upon well performance and ultimate recovery of hydraulically fractured gas wells  

E-Print Network [OSTI]

EFFECTS OF FRACTURING FLUID RECOVERY UPON WELL PERFORMANCE AND ULTIMATE RECOVERY OF HYDRAULICALLY FRACTURED GAS WELLS A Thesis IAN MARIE BERTHELOT Submitted to the Office of Graduate Studies of Texas AdtM University in partial fulfillment... of the requirements for the degree of MASTER OF SCIENCE May 1990 Major Subject: Petroleum Engineering EFFECTS OF FRACTURING FLUID RECOVERY UPON WELL PERFORMANCE AND ULTIMATE RECOVERY OF HYDRAULICALLY FRACTURED GAS WELLS by JAN MARIE BERTIIELOT Appmved...

Berthelot, Jan Marie

2012-06-07T23:59:59.000Z

324

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

Office of Environmental Management (EM)

Fluids Shale Gas Development Challenges: Fracture Fluids More Documents & Publications Natural Gas from Shale: Questions and Answers Shale Gas Glossary FracFocus 2.0 Task Force...

325

Hydraulic fracturing and shale gas extraction.  

E-Print Network [OSTI]

??In the past decade the technique of horizontal drilling and hydraulic fracturing has been improved so much that it has become a cost effective method… (more)

Klein, Michael

2012-01-01T23:59:59.000Z

326

Geomechanical review of hydraulic fracturing technology .  

E-Print Network [OSTI]

??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… (more)

Arop, Julius Bankong

2013-01-01T23:59:59.000Z

327

Method of fracturing a geological formation  

DOE Patents [OSTI]

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.

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

1990-01-01T23:59:59.000Z

328

Fracture characteristics and their relationships to producing...  

Open Energy Info (EERE)

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

329

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...

330

Structural Settings Of Hydrothermal Outflow- Fracture Permeability...  

Open Energy Info (EERE)

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

331

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...

332

Regional Analysis And Characterization Of Fractured Aquifers...  

Open Energy Info (EERE)

geothermal applications include the recognition of and exploration for deep fracture permeability in crystalline rocks. It is well known that the best currently available...

333

Microearthquake Technology for EGS Fracture Characterization...  

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

1 4.5.1 Microearthquake Technology for EGS Fracture Characterization Presentation Number: 021 Investigator: Foulger, Gillian (Foulger Consulting) Objectives: To understand how EGS...

334

Naturally fractured tight gas reservoir detection optimization  

SciTech Connect (OSTI)

The work plan for the quarter of October 1, 1997--December 31, 1997 consisted of two tasks: (1) Present results of Rulison field test at various conferences, seminars, and to Barrett Resources and Snyder Oil Co. and (2) Continue work into developing a predictive quantitative method for locating fault-related natural fractures. The first task was completed during this reporting period. The second task continues the beginning of quantitative fracture mechanics analysis of the geologic processes that are involved for the development of fault-related natural fractures. The goal of this work is to develop a predictive capability of locating natural fractures prior to drilling.

NONE

1998-09-30T23:59:59.000Z

335

Geometrical and transport properties of single fractures: influence of the roughness of the fracture  

E-Print Network [OSTI]

Geometrical and transport properties of single fractures: influence of the roughness of the fracture walls H. Auradou Univ Pierre et Marie Curie-Paris6, Univ Paris-Sud, CNRS, F-91405. Lab FAST, Bat reviews the main features of the transport properties of single fractures. A particular attention paid

Paris-Sud XI, Université de

336

Laboratory-scale fracture conductivity created by acid etching  

E-Print Network [OSTI]

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...

Pournik, Maysam

2009-05-15T23:59:59.000Z

337

MULTIDIMENSIONAL NUMERICAL SIMULATION OF FLUID FLOW IN FRACTURED POROUS MEDIA  

E-Print Network [OSTI]

and fluid flow in the hydraulic fracturing process." Ph.D.depth by means of hydraulic fracturing." in Rock Mechanics:Fig. 13. Simulation of hydraulic fracturing: field data on

Narasimhan, T.N.

2014-01-01T23:59:59.000Z

338

A PKN Hydraulic Fracture Model Study and Formation Permeability Determination  

E-Print Network [OSTI]

Hydraulic fracturing is an important method used to enhance the recovery of oil and gas from reservoirs, especially for low permeability formations. The distribution of pressure in fractures and fracture geometry are needed to design conventional...

Xiang, Jing

2012-02-14T23:59:59.000Z

339

FINITE FRACTURE MECHANICS OF MATRIX MICROCRACKING IN COMPOSITES  

E-Print Network [OSTI]

FINITE FRACTURE MECHANICS OF MATRIX MICROCRACKING IN COMPOSITES JOHN A. NAIRN INTRODUCTION damage following complex loading conditions. This chapter describes a fracture mechanics approach to the microcracking problem. A complicating feature of composite fracture mechanics analysis is that laminates often

Nairn, John A.

340

Seismic characterization of fractured reservoirs using 3D double beams  

E-Print Network [OSTI]

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 ...

Zheng, Yingcai

2012-01-01T23:59:59.000Z

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


341

Rock-Fluid Chemistry Impacts on Shale Hydraulic Fracture and Microfracture Growth  

E-Print Network [OSTI]

fracturing fluids, to achieve improved fracture performance and higher recovery of natural gas from shale reservoirs....

Aderibigbe, Aderonke

2012-07-16T23:59:59.000Z

342

Coupled thermohydromechanical analysis of a heater test in unsaturated clay and fractured rock at Kamaishi Mine  

E-Print Network [OSTI]

injection and hydraulic fracturing stress measurements inlevel measured with hydraulic fracturing (reproduced from

Rutqvist, J.

2011-01-01T23:59:59.000Z

343

Modeling Single Well Injection-Withdrawal (SWIW) Tests for Characterization of Complex Fracture-Matrix Systems  

E-Print Network [OSTI]

exchange process. Hydraulic fracturing, or hydrofracking, ismore detail below. Hydraulic fracturing, or hydrofracking,

Cotte, F.P.

2012-01-01T23:59:59.000Z

344

E-Print Network 3.0 - apophyseal ring fracture Sample Search...  

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

fracture Search Powered by Explorit Topic List Advanced Search Sample search results for: apophyseal ring fracture...

345

Aging and Fracture of Human Cortical Bone and Tooth Dentin  

E-Print Network [OSTI]

in both biological materials, resistance to fracture arisesof fracture resistance in these biological materials, asresistance path along these interfaces through the material.

Ager III, Joel W.

2008-01-01T23:59:59.000Z

346

Numerical Modeling of Hydraulic Fracturing in Oil Sands  

E-Print Network [OSTI]

Hydraulic fracturing is a widely used and e cient technique for enhancing oil ... for analyzing hydraulic fracturing in rocks, are in general not satisfactory for oil ...

2008-11-16T23:59:59.000Z

347

Finite element modeling of hydraulic fracturing in 3D  

E-Print Network [OSTI]

Mar 22, 2013 ... Two examples of hydraulic fracturing are given. when the pressure buildup ... Hydraulic fracturing is the coupled dynamics of frac- ture and ?uid ...

2013-03-22T23:59:59.000Z

348

Seismic Studies of a Massive Hydraulic Fracturing Experiment...  

Open Energy Info (EERE)

a Massive Hydraulic Fracturing Experiment Jump to: navigation, search OpenEI Reference LibraryAdd to library Conference Paper: Seismic Studies of a Massive Hydraulic Fracturing...

349

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

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

define the subsurface system of fractures and mapping of fluid flow. * limited fracture detection capability * lack of high-temperature monitoring tools and sensors *...

350

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

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

Efficient Use of MEQ Data Auto-picker Soft Computing Triggered vs induced seismicity. Fracture Mapping Fractal Dimensions Hot dry rock fracture regime Monitoring FluidTemp Dynamic...

351

The Role of Geochemistry and Stress on Fracture Development and...  

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

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

352

Detecting Fractures Using Technology at High Temperatures and...  

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

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

353

Tracer Methods for Characterizing Fracture Creation in Enhanced...  

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

Tracer Methods for Characterizing Fracture Creation in Enhanced Geothermal Systems; 2010 Geothermal Technology Program Peer Review Report Tracer Methods for Characterizing Fracture...

354

Fracture Characterization in Enhanced Geothermal Systems by Wellbore...  

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

Fracture Characterization in Enhanced Geothermal Systems by Wellbore and Reservoir Analysis Fracture Characterization in Enhanced Geothermal Systems by Wellbore and Reservoir...

355

Fracture Network and Fluid Flow Imaging for EGS Applications...  

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

Fracture Network and Fluid Flow Imaging for EGS Applications from Multi-Dimensional Electrical Resistivity Structure Fracture Network and Fluid Flow Imaging for EGS Applications...

356

Detecting Fractures Using Technology at High Temperatures and...  

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

Fractures Using Technology at High Temperatures and Depths - Geothermal Ultrasonic Fracture Imager (GUFI) Presentation Number: 015 Investigator: Patterson, Doug (Baker Hughes...

357

Imaging, Characterizing, and Modeling of Fracture Networks and...  

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

Imaging, Characterizing, and Modeling of Fracture Networks and Fluid Flow in EGS Reservoirs Imaging, Characterizing, and Modeling of Fracture Networks and Fluid Flow in EGS...

358

Irradiation Effects on Human Cortical Bone Fracture Behavior  

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

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

359

Imaging, Characterizing, and Modeling of Fracture Networks and...  

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

Imaging, Characterizing, and Modeling of Fracture Networks and Fluid Flow in EGS Reservoirs Lianjie Huang Los Alamos National Lab Seismicity and Reservoir Fracture Characterization...

360

Fracture Evolution Following a Hydraulic Stimulation within an...  

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

define the subsurface system of fractures and mapping of fluid flow. * limited fracture detection capability * lack of high-temperature monitoring tools and sensors *...

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


361

Fracture Characterization in Enhanced Geothermal Systems by Wellbore...  

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

Fracture Characterization in Enhanced Geothermal Systems by Wellbore and Reservoir Analysis; 2010 Geothermal Technology Program Peer Review Report Fracture Characterization in...

362

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

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

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

363

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....

364

Fracture Evolution Following a Hydraulic Stimulation within an...  

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

Fracture Evolution Following a Hydraulic Stimulation within an EGS Reservoir Fracture Evolution Following a Hydraulic Stimulation within an EGS Reservoir DOE Geothermal Peer Review...

365

Displacement and segment linkage in fracture zones  

SciTech Connect (OSTI)

Fault zones and vein arrays are composed of overstepping and linked segments, so knowledge of segment evolution is crucial in understanding the development of zones. Displacement-distance profiles of faults and veins are used to study the development of segments and zones. Detailed mapping of normal and strike-slip faults allows comparison of the displacement-distance characteristics of faults both normal and parallel to the displacement vector, i.e. modes III and II propagation respectively. Similarly, vein width variations can be used to study mode I propagation. Displacement varies with distance along fractures, with zero displacement at fracture tips. Steep displacement gradients can occur where faults and extension fractures overstep because of displacement transfer between the segments. This displacement transfer is accommodated by relay and bridge structures. Overstepping fractures may link to form a single fracture with an irregular displacement-distance profile. A linkage point is often marked by a bend with a displacement minimum, where relay/bridge structures are preserved as normal drag. Displacement variations are also caused by fault bends, conjugate relationships and by lithological variations. As interaction between fractures increases, r/d[sub MAX] ratios tend to decrease (where r = the distance between the tip and the point of maximum displacement, and d[sub MAX] = maximum displacement). As a result of the interaction of fracture segments, fracture zones tend to have complex displacement-distance profiles.

Peacock, D.C.P.; Sanderson, D.J. (Univ. of Southampton (United Kingdom). Dept. of Geology)

1992-01-01T23:59:59.000Z

366

Harmonic experiments to model fracture induced anisotropy  

E-Print Network [OSTI]

´oleo (IGPUBA), Universidad de Buenos Aires, Argentina, and Universidad Nacional de La Plata, Argentina. work;Fractured media. III · Displacement discontinuities conserve energy, while velocity discontinuities generate energy loss at the fractures. The specific viscosity accounts for the presence of a liquid under

Santos, Juan

367

Harmonic experiments to model fracture induced anisotropy  

E-Print Network [OSTI]

´oleo (IGPUBA), Universidad de Buenos Aires, Argentina, and Universidad Nacional de La Plata, Argentina. work;Fractured media. III Displacement discontinuities conserve energy, while velocity discontinuities generate energy loss at the fractures. The specific viscosity accounts for the presence of a liquid under

Santos, Juan

368

A synergistic approach to optimizing hydraulic fracturing  

SciTech Connect (OSTI)

Combining measurement, simulation, and imaging technologies into an integrated program can help operators achieve the best hydraulic fracture treatment possible. Hydrocarbon production can be significantly increased when fractures are extended to the planned length, and fracturing fluid is retained within the zone of interest. Fractures that break out of zone increase the risk of excess water production with the hydrocarbon. Consequently, the ability to select suitable operational parameters for hydraulic fracturing is critical to job success. An evaluation of formation properties and potential barriers to hydraulic fracturing can be made with three-dimensional (3D) simulation to integrate data taken from wireline logs, waveform sonic logs, and microfrac measurements. In-situ stress orientation is determined by use of a downhole extensometer, oriented cores, anelastic strain recovery (ASR) measurements, and borehole imaging logs. Sidewall cores can be taken perpendicular to wellbore walls without distorting the borehole or the core taken; orientation of the cores can be determined with imaging logs run after coring. Natural fractures can be viewed with a downhole video camera lowered into the well on fiberoptic cable. Effectiveness of fracture treatments may be evaluated with various gamma ray logging techniques production logs comparing expected production to actual zonal contribution. Refined procedures that result from after-frac analysis can be used to plain field development for optimal reservoir drainage.

Kessler, C.; Venditto, J.; McMechan, D.; Edwards, P.

1994-12-31T23:59:59.000Z

369

Fracture mechanics of cellular glass  

SciTech Connect (OSTI)

Cellular glasses are prime candidate materials for the structural substrate of mirrored glass for solar concentrator reflecting panels. These materials are brittle, however, and susceptible to mechanical failure from slow crack growth caused by a stress corrosion mechanism. The results are detailed of one part of a program established to develop improved cellular glasses and to characterize the behavior of these and commercially available materials. Commercial and developmental cellular glasses were tested and analyzed using standard testing techniques and models developed from linear fracture mechanics. Two models describing the fracture behavior of these materials are developed. Slow crack growth behavior in cellular glass was found to be more complex than that encountered in dense glasses or ceramics. The crack velocity was found to be strongly dependent upon water vapor transport to the tip of the moving crack. The existence of a static fatigue limit was not conclusively established, however, it is speculated that slow crack growth behavior in Region I may be slower, by orders of magnitude, than that found in dense glasses.

Zwissler, J.G.; Adams, M.A.

1981-02-01T23:59:59.000Z

370

Hydraulic fracturing slurry transport in horizontal pipes  

SciTech Connect (OSTI)

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.

Shah, S.N.; Lord, D.L. (Halliburton Services (US))

1990-09-01T23:59:59.000Z

371

Self-potential observations during hydraulic fracturing  

SciTech Connect (OSTI)

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

Moore, Jeffrey R.; Glaser, Steven D.

2007-09-13T23:59:59.000Z

372

Fully coupled fluid flow and geomechanics in the study of hydraulic fracturing and post-fracture production.  

E-Print Network [OSTI]

??This work addresses the poroelastic effect on the processes involved in hydraulic fracturing and post-fracture production using a finite element based fully coupled poroelastic model… (more)

Aghighi, Mohammad Ali

2007-01-01T23:59:59.000Z

373

The influence of fracture properties on ground-water flow at the Bunker Hill Mine, Kellogg, Idaho  

SciTech Connect (OSTI)

The Bunker Hill Mine in northern Idaho is a large underground lead-zinc mine located in Precambrian metaquartzite rocks with virtually no primary porosity. Ground-water flow through these types of rocks is largely dependent upon the properties of fractures such as joints, faults and relict bedding planes. Ground water that flows into the mine via the fractures is contaminated by heavy metals and by the production of acid water, which results in a severe acid mine drainage problem. A more complete understanding of how the fractures influence the ground-water flow system is a prerequisite to the evaluation of reclamation alternatives to reduce acid drainage from the mine. Fracture mapping techniques were used to obtain detailed information on the fracture properties observed in the New East Reed drift of the Bunker Hill Mine. The data obtained include: (a) fracture type, (b) orientation, (c) trace length, (d) the number of visible terminations, (e) roughness (small-scale asperities), (f) waviness (larger-scale undulations), (g) infilling material, and (h) a qualitative measure of the amount of water flowing through each fracture.

Lachmar, T.E. [Utah State Univ., Logan, UT (United States). Dept. of Geology

1993-12-01T23:59:59.000Z

374

Operating the LCLS Gas Attenuator and Gas Detector System with Apertures of 6mm Diameter  

SciTech Connect (OSTI)

The possibility of increasing the apertures of the LCLS gas attenuator/gas detector system is considered. It is shown that increase of the apertures from 3 to 6 mm, together with 4-fold reduction of the operation pressure does not adversely affect the vacuum conditions upstream or downstream. No change of the pump speed and the lengths of the differential pumping cells is required. One minor modification is the use of 1.5 cm long tubular apertures in the end cells of the differential pumping system. Reduction of the pressure does not affect performance of the gas attenuator/gas detector system at the FEL energies below, roughly, 2 keV. Some minor performance degradation occurs at higher energies.

Ryutov, D.D.; Bionta, R.M.; Hau-Riege, S.P.; Kishiyama, K.I.; Roeben, M.D.; Shen, S.; /LLNL, Livermore; Stefan, P.M.; /SLAC; ,

2010-11-17T23:59:59.000Z

375

LNG cascading damage study. Volume I, fracture testing report.  

SciTech Connect (OSTI)

As part of the liquefied natural gas (LNG) Cascading Damage Study, a series of structural tests were conducted to investigate the thermal induced fracture of steel plate structures. The thermal stresses were achieved by applying liquid nitrogen (LN{sub 2}) onto sections of each steel plate. In addition to inducing large thermal stresses, the lowering of the steel temperature simultaneously reduced the fracture toughness. Liquid nitrogen was used as a surrogate for LNG due to safety concerns and since the temperature of LN{sub 2} is similar (-190 C) to LNG (-161 C). The use of LN{sub 2} ensured that the tests could achieve cryogenic temperatures in the range an actual vessel would encounter during a LNG spill. There were four phases to this test series. Phase I was the initial exploratory stage, which was used to develop the testing process. In the Phase II series of tests, larger plates were used and tested until fracture. The plate sizes ranged from 4 ft square pieces to 6 ft square sections with thicknesses from 1/4 inches to 3/4 inches. This phase investigated the cooling rates on larger plates and the effect of different notch geometries (stress concentrations used to initiate brittle fracture). Phase II was divided into two sections, Phase II-A and Phase II-B. Phase II-A used standard A36 steel, while Phase II-B used marine grade steels. In Phase III, the test structures were significantly larger, in the range of 12 ft by 12 ft by 3 ft high. These structures were designed with more complex geometries to include features similar to those on LNG vessels. The final test phase, Phase IV, investigated differences in the heat transfer (cooling rates) between LNG and LN{sub 2}. All of the tests conducted in this study are used in subsequent parts of the LNG Cascading Damage Study, specifically the computational analyses.

Petti, Jason P.; Kalan, Robert J.

2011-12-01T23:59:59.000Z

376

Effect of beam limiting aperture and collector potential on multi-element focused ion beams  

SciTech Connect (OSTI)

A compact microwave driven plasma based multi-element focused ion beam system has been developed. In the present work, the effect of reduced beam limiter (BL) aperture on the focused ion beam parameters, such as current and spot size, and a method of controlling beam energy independently by introducing a biased collector at focal point (FP) are investigated. It is found that the location of FP does not change due to the reduction of BL aperture. The location of FP and beam size are found to be weakly dependent on the collector potential in the range from -8 kV to -18 kV.

Paul, Samit; Chowdhury, Abhishek; Bhattacharjee, Sudeep [Department of Physics, Indian Institute of Technology, Kanpur, Uttar Pradesh (India)

2012-02-15T23:59:59.000Z

377

Characterizing hydraulically fractured reservoirs using induced microearthquakes  

SciTech Connect (OSTI)

Hydraulic fracturing is a common method employed to increase the production of oil and gas fields. Recently, there has been increased interest in monitoring the microearthquakes induced by hydraulic fracturing as a means of obtaining data to characterize reservoir changeS induced by the injection. Two types of microearthquakes have been observed during hydraulic fracturing. Tensile events have been observed and modeled as the parting of the surfaces of a fracture. A majority of the events observed have been shear-slip events, where two sides of a fault plane slip parallel to each other but in opposite directions. The locations of the microearthquakes can be analyzed to determine regions where significant seismic energy was released, which presumably are regions where injected fluid penetrated into the rock along pre-existing fractures or zones of weakness. The spatial patterns in the locations can be analyzed to fine regions where events cluster along planes, which are interpreted to be the dominant fluid flow paths. Imaging methods can also be applied to the travel time and waveform data to obtain direct evidence for the locations of the fractures or fracture zones. 27 refs., 2 figs.

Fehler, M.

1991-01-01T23:59:59.000Z

378

Well testing model for multi-fractured horizontal well for shale gas reservoirs with consideration of dual diffusion in matrix  

Science Journals Connector (OSTI)

Abstract Shale gas reservoir is typical unconventional reservoir, it's necessary to take advantage of multi-stage fractured horizontal well so as to develop those kinds of reservoirs, which can form high conductivity hydraulic fractures and activate natural fractures. Due to the existence of concentration gap between matrix and fractures, desorption gas can simultaneously diffuse into the natural fractures and hydraulic fractures. This process can be called dual diffusion. Based on the triple-porosity cubic model, this paper establishes a new well testing model of multi-stage fractured horizontal well in shale gas reservoir with consideration of the unique mechanisms of desorption and dual diffusion in matrix. Laplace transformation is employed to solve this new model. The pseudo pressure transient responses are inverted into real time space with stehfest numerical inversion algorithm. Type curves are plotted, and different flow regimes in shale gas reservoirs are identified and the effects of relevant parameters are analyzed as well. Considering the mechanism of dual diffusion in matrix, the flow can be divided into five regimes: early linear flow; pseudo-steady state inter-porosity flow; the diffusion from matrix into micro-fractures; the diffusion from matrix into hydraulic fractures and boundary-dominated flow. There are large distinctions of pressure response between pseudo steady state diffusion and unsteady state diffusion under different value of pore volume ratio. It's similar to the feature of pseudo-steady state inter-porosity flow, diffusion coefficient and Langmuir parameters reflect the characters of pseudo-steady state diffusion. The numbers of stage of hydraulic fractures have certain impact on the shape factor of matrix and the inter-porosity coefficient. This new model is validated compared with some existing models. Finally, coupled with an application, this mew model can be approximately reliable and make some more precise productivity prediction.

Leng Tian; Cong Xiao; Mingjin Liu; Daihong Gu; Guangyu Song; Helong Cao; Xianglong Li

2014-01-01T23:59:59.000Z

379

Testing sand used in hydraulic fracturing operations  

SciTech Connect (OSTI)

Recommended practices for testing sand used in hydraulic fracturing operations are outlined as developed by the Task Group on Evaluation of Hydraulic Fracturing Sand under the API Subcommittee on Evaluation of Well Completion Materials. The tests recommended were developed to improve the quality of frac sand delivered to the well site, and are for use in evaluating certain physical properties of sand used in hydraulic fracturing operations. The tests suggested enable users to compare physical characteristics of various sands and to select materials most useful for such applications. Parameters to be tested include turbidity, clay and soft particle content, crush resistance, and mineralogic analysis.

Not Available

1983-03-01T23:59:59.000Z

380

Reply to Davies: Hydraulic fracturing remains a possible mechanism for  

E-Print Network [OSTI]

LETTER Reply to Davies: Hydraulic fracturing remains a possible mechanism for observed methane mechanisms were leaky gas well casings and the possibility that hydraulic fracturing might generate new- knowledged the possibility of hydraulic fracturing playing a role. Is it possible that hydraulic fracturing

Jackson, Robert B.

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


381

Coupling schemes for modeling hydraulic fracture propagation using the XFEM  

E-Print Network [OSTI]

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

Peirce, Anthony

382

Calibration of hydraulic and tracer tests in fractured media  

E-Print Network [OSTI]

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

Politècnica de Catalunya, Universitat

383

Envelope of Fracture Density Dragana Todorovic-Marinic*  

E-Print Network [OSTI]

Envelope of Fracture Density Dragana Todorovic-Marinic* Veritas DGC Ltd., Calgary, Alberta, Canada that interpretation of fractures can be improved by using the envelope of the fracture density. It has been shown that open, fluid (or gas) filled fractures can be identified through the use of the AVAZ method (Gray et. al

Santos, Juan

384

Use of Tracers to Characterize Fractures in Engineered Geothermal Systems  

Broader source: Energy.gov [DOE]

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

385

Structure and fracture resistance of alligator gar (Atractosteus spatula) armored fish scales  

E-Print Network [OSTI]

Structure and fracture resistance of alligator gar (Atractosteus spatula) armored fish scales Wen is a large fish with flexible armor consisting of ganoid scales. These scales contain a thin layer of ganoine Fish scales are lightweight flexible dermal armor. They charac- teristically overlap; besides

Meyers, Marc A.

386

1008 ieee transactions on ultrasonics, ferroelectrics, and frequency control, vol. 53, no. 5, may 2006 An Iterative Synthetic Aperture Imaging  

E-Print Network [OSTI]

as synthetic aperture focusing technique (SAFT) [1] has been inspired by synthetic aperture sonar (SAS) [2] and synthetic aper- ture radar (SAR) [3]. SAFT has been applied both in med- ical and nondestructive material that this technique is superior to many other common SAI algo- rithms, such as conventional SAFT and phased-array tech

387

Physical model of a fractured reservoir | Open Energy Information  

Open Energy Info (EERE)

model of a fractured reservoir model of a fractured reservoir Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Conference Proceedings: Physical model of a fractured reservoir Details Activities (1) Areas (1) Regions (0) Abstract: The objectives of the physical modeling effort are to: (1) evaluate injection-backflow testing for fractured reservoirs under conditions of known reservoir parameters (porosity, fracture width, etc.); (2) study the mechanisms controlling solute transport in fracture systems; and (3) provide data for validation of numerical models that explicitly simulate solute migration in fracture systems. The fracture network is 0.57-m wide, 1.7-m long, and consists of two sets of fractures at right angles to one another with a fracture spacing of 10.2 cm. A series of

388

Aperture Test for Internal Target Operation in the JLAB High-current ERL  

SciTech Connect (OSTI)

A high current beam transmission test has been successfully completed at the JLAB FEL Facility, culminating in very low-loss transmission of a high current CW beam through a small aperture. The purpose of this test was to determine if an ERL is capable of meeting the stringent requirements imposed by the use of a 1018/cm3 internal gas target proposed for the DarkLight experiment*. Minimal beamline modifications were made to create a machine configuration that is substantially different from those used in routine UV or IR FEL operation. A sustained (8 hour) high power beam run was performed, with clean transmission through a 2 mm transverse aperture of 127 mm length simulating the target configuration. A beam size of 50 um (rms) was measured near the center of the aperture. Experimental data from a week-long test run consistently exhibited beam loss of only a few ppm on the aperture while running 4.5 mA current at 100 MeV -- or nearly 0.5 MW beam power. This surpassed the users? expectation and demonstrated a unique capability of an ERL for this type of experiments. This report presents a summary of the experiment, a brief overview of our activities, and outlines future plans.

Zhang, Shukui

2013-06-01T23:59:59.000Z

389

Building starting model for full waveform inversion from wide-aperture data by stereotomography  

E-Print Network [OSTI]

Building starting model for full waveform inversion from wide-aperture data by stereotomography CGG Veritas, Massy, France; 3 LGIT - UJF - CNRS, France Abstract Building reliable starting model). In this study, we assess the stereotomography as a tool to build reliable starting model for frequency

Vallée, Martin

390

Basics of Polar-Format algorithm for processing Synthetic Aperture Radar images.  

SciTech Connect (OSTI)

The purpose of this report is to provide a background to Synthetic Aperture Radar (SAR) image formation using the Polar Format (PFA) processing algorithm. This is meant to be an aid to those tasked to implement real-time image formation using the Polar Format processing algorithm.

Doerry, Armin Walter

2012-05-01T23:59:59.000Z

391

Rock glacier surface motion in Beacon Valley, Antarctica, from synthetic-aperture radar interferometry  

E-Print Network [OSTI]

al., 1998]. [5] Although subsurface ice in Beacon Valley has long been known [Linkletter et al., 1973Rock glacier surface motion in Beacon Valley, Antarctica, from synthetic-aperture radar of rock glaciers in the Beacon Valley sector of the McMurdo Dry Valleys, in East Antarctica, as part

Fountain, Andrew G.

392

Rock Joint Surfaces Measurement and Analysis of Aperture Distribution under Different Normal and Shear Loading Using GIS  

E-Print Network [OSTI]

Geometry of the rock joint is a governing factor for joint mechanical and hydraulic behavior. A new method of evaluating aperture distribution based on measurement of joint surfaces and three dimensional characteristics of each surface is developed. Artificial joint of granite surfaces are measured,processed, analyzed and three dimensional approaches are carried out for surface characterization. Parameters such as asperity's heights, slope angles, and aspects distribution at micro scale,local concentration of elements and their spatial localization at local scale are determined by Geographic Information System (GIS). Changes of aperture distribution at different normal stresses and various shear displacements are visualized and interpreted. Increasing normal load causes negative changes in aperture frequency distribution which indicates high joint matching. However, increasing shear displacement causes a rapid increase in the aperture and positive changes in the aperture frequency distribution which could be ...

Sharifzadeh, Mostafa; Esaki, Tetsuro

2009-01-01T23:59:59.000Z

393

Influence of fracture scale heterogeneity on the flow properties of three-dimensional discrete fracture networks (DFN)  

E-Print Network [OSTI]

Influence of fracture scale heterogeneity on the flow properties of three-dimensional discrete fracture networks (DFN) J.-R. de Dreuzy,1,2 Y. Méheust,2 and G. Pichot3 Received 18 May 2012; revised 28 of fractured media has been so far studied independently at the fracture- and network- scales, we propose

Paris-Sud XI, Université de

394

Using the fracture energies for the two films a first estimate of fracture toughness, K, can be found.  

E-Print Network [OSTI]

· Using the fracture energies for the two films a first estimate of fracture toughness, K, can be found. · Assumptions are made to estimate the crack area based on the fracture mode seen in the SEM. · The total crack length is assumed to be 3 times the contact radius, , at the fracture depth. · To find

Collins, Gary S.

395

A Fracture-Mechanics-Based Approach to Fracture Control in Biomedical Devices Manufactured From Superelastic Nitinol Tube  

E-Print Network [OSTI]

A Fracture-Mechanics-Based Approach to Fracture Control in Biomedical Devices Manufactured From: 10.1002/jbm.b.30840 Abstract: Several key fracture-mechanics parameters associated with the onset of subcritical and critical cracking, specifically the fracture toughness, crack-resistance curve, and fatigue

Ritchie, Robert

396

Hydraulic fracturing accelerates coalbed methane recovery  

SciTech Connect (OSTI)

Methane production from deep coal seams that never will be mined requires hydraulic fracturing for faster, optimal recovery. Since this can be a complex process, proper formation evaluation beforehand is essential, according to this paper.

Holditch, S.A. (Texas A and M Univ. (US)); Ely, J.W.; Semmelbeck, M.E.; Carter, R.H. (S.A. Holditch and Associates (US)); Hinkel, J.J.; Jeffrey, R.G. Jr. (Dowell Schlumberger (US))

1990-11-01T23:59:59.000Z

397

Multiphase flow in fractured porous media  

SciTech Connect (OSTI)

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.

Firoozabadi, A.

1995-02-01T23:59:59.000Z

398

Universal asymptotic umbrella for hydraulic fracture modeling  

E-Print Network [OSTI]

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.

Linkov, Aleksandr M

2014-01-01T23:59:59.000Z

399

Environmental challenges in fracturing of unconventional resources  

Science Journals Connector (OSTI)

...Fracturing and the environment. This talk showed...environmental risks and impacts associated with gas...time protecting the environment and safeguarding...Duncan, P. , 2011, Fracking and the environment: The contribution...

Azra N. Tutuncu; Chris Krohn; Stephan Gelinsky; Jacques Leveille; Cengiz Esmersoy; Ali I. Mese

400

Dynamic Fracture Toughness of Polymer Composites  

E-Print Network [OSTI]

that of defense or transport. In this project, the focus is on determining dynamic fracture toughness property of fiber reinforced polymer composites by using a combined numerical- experimental methodology. Impact tests are conducted on Split-Hopkinson pressure...

Harmeet Kaur

2012-02-14T23:59:59.000Z

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


401

Anomalous transport through porous and fractured media  

E-Print Network [OSTI]

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 ...

Kang, Peter Kyungchul

2014-01-01T23:59:59.000Z

402

Advanced hydraulic fracturing methods to create in situ reactive barriers  

SciTech Connect (OSTI)

Many contaminated areas consist of a source area and a plume. In the source area, the contaminant moves vertically downward from a release point through the vadose zone to an underlying saturated region. Where contaminants are organic liquids, NAPL may accumulate on the water table, or it may continue to migrate downward through the saturated region. Early developments of permeable barrier technology have focused on intercepting horizontally moving plumes with vertical structures, such as trenches, filled with reactive material capable of immobilizing or degrading dissolved contaminants. This focus resulted in part from a need to economically treat the potentially large volumes of contaminated water in a plume, and in part from the availability of construction technology to create the vertical structures that could house reactive compounds. Contaminant source areas, however, have thus far remained largely excluded from the application of permeable barrier technology. One reason for this is the lack of conventional construction methods for creating suitable horizontal structures that would place reactive materials in the path of downward-moving contaminants. Methods of hydraulic fracturing have been widely used to create flat-lying to gently dipping layers of granular material in unconsolidated sediments. Most applications thus far have involved filling fractures with coarse-grained sand to create permeable layers that will increase the discharge of wells recovering contaminated water or vapor. However, it is possible to fill fractures with other compounds that alter the chemical composition of the subsurface. One early application involved development and field testing micro-encapsulated sodium percarbonate, a solid compound that releases oxygen and can create aerobic conditions suitable for biodegradation in the subsurface for several months.

Murdoch, L. [FRx Inc., Cincinnati, OH (United States); [Clemson Univ., SC (United States); Siegrist, B. [Oak Ridge National Lab., TN (United States); Vesper, S. [Univ. of Cincinnati, OH (United States)] [and others

1997-12-31T23:59:59.000Z

403

TRITIUM EFFECTS ON WELDMENT FRACTURE TOUGHNESS  

SciTech Connect (OSTI)

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

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

2006-07-17T23:59:59.000Z

404

Gas condensate damage in hydraulically fractured wells  

E-Print Network [OSTI]

), md 0.15 Porosity (g102), fraction 0.1 Water Saturation (S w ), fraction 0.16 Initial Pressure (p i ), psi 3,900 Injection Pressure (p inj ), psi 3,910 Dewpoint Pressure (p d ), psi 3,500 Temperature (T), o F 200 Total Compressibility (c g... simulation ..........................13 3.4 Permeability reduction normal to fracture face .........................................14 3.5 Quarter model for 80 acre drainage area....................................................15 3.6 Fracture face...

Adeyeye, Adedeji Ayoola

2004-09-30T23:59:59.000Z

405

Production-systems analysis for fractured wells  

SciTech Connect (OSTI)

Production-systems analysis has been in use for many years to design completion configurations on the basis of an expected reservoir capacity. The most common equations used for the reservoir calculations are for steady-state radial flow. Most hydraulically fractured wells require the use of an unsteady-state production simulator to predict the higher flow rates associated with the stimulated well. These high flow rates may present problems with excessive pressure drops through production tubing designed for radial-flow production. Therefore, the unsteady-state nature of fractured-well production precludes the use of steady-state radial-flow inflow performance relationships (IPR's) to calculate reservoir performance. An accurate prediction of fractured-well production must be made to design the most economically efficient production configuration. It has been suggested in the literature that a normalized reference curve can be used to generate the IPR's necessary for production-systems analysis. However, this work shows that the reference curve for fractured-well response becomes time-dependent when reservoir boundaries are considered. A general approach for constructing IPR curves is presented, and the use of an unsteady-state fractured-well-production simulator coupled with the production-systems-analysis approach is described. A field case demonstrates the application of this method to fractured wells.

Hunt, J.L. (Halliburton Services (US))

1988-11-01T23:59:59.000Z

406

A STATISTICAL FRACTURE MECHANICS APPROACH TO THE STRENGTH OF BRITTLE ROCK  

E-Print Network [OSTI]

Carlsson, H. , "Hydraulic fracturing and overcoring stress1949). Haimson, B.C. , "Hydraulic fracturing in porous andc.B. , "Laboratory hydraulic fracturing experiments in

Ratigan, J.L.

2010-01-01T23:59:59.000Z

407

Pressure analysis of the hydromechanical fracture behaviour in stimulated tight sedimentary geothermal reservoirs  

E-Print Network [OSTI]

Zimmermann, G. , 2005. Hydraulic fracturing in a sedimentaryare described in the hydraulic fracturing context, in whichoverview. However, hydraulic fracturing theories and related

Wessling, S.

2009-01-01T23:59:59.000Z

408

HYDRAULIC FRACTURING AND OVERCORING STRESS MEASUREMENTS IN A DEEP BOREHOLE AT THE STRIPA TEST MINE, SWEDEN  

E-Print Network [OSTI]

u l y 2 , 1 9 8 1 HYDRAULIC FRACTURING AND OVERCORING STRESSI nun LBL-12478 HYDRAULIC FRACTURING AND OVERCORING STRESSthe calculated stress. n HYDRAULIC FRACTURING EQUIPMENT AND

Doe, T.

2010-01-01T23:59:59.000Z

409

Skull fracture vs. accessory sutures: how can we tell the difference?  

E-Print Network [OSTI]

fissure: diagnosis of fracture versus anatomic variants.be performed to identify fractures in suspected child abuse?skull: the diagnosis of fracture. Am J Roentgenol Radium

Sanchez, Thomas; Stewart, Deborah; Walvick, Matthew; Swischuk, Leonard

2010-01-01T23:59:59.000Z

410

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

E-Print Network [OSTI]

New Model of Hydraulic Fracture With an Induced Low Velocityand L. R. Meyer, 1988. Fracture Detectin Using P- Wave andof a Vertical Hydraulic Fracture, Earth Sciences Division,

Nelson, J.T.

2009-01-01T23:59:59.000Z

411

E-Print Network 3.0 - adjacent compression fractures Sample Search...  

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

and triangular columns formed by column-bounding fractures adjacent to inflation-fracture walls... the cooling rate, caus- ing increased fracturing ... Source: Kattenhorn,...

412

Fracture behavior of circumferentially surface-cracked elbows. Technical report, October 1993--March 1996  

SciTech Connect (OSTI)

This report presents the results from Task 2 of the Second International Piping Integrity Research Group (IPIRG-2) program. The focus of the Task 2 work was directed towards furthering the understanding of the fracture behavior of long-radius elbows. This was accomplished through a combined analytical and experimental program. J-estimation schemes were developed for both axial and circumferential surface cracks in elbows. Large-scale, quasi-static and dynamic, pipe-system, elbow fracture experiments under combined pressure and bending loads were performed on elbows containing an internal surface crack at the extrados. In conjunction with the elbow experiments, material property data were developed for the A106-90 carbon steel and WP304L stainless steel elbow materials investigated. A comparison of the experimental data with the maximum stress predictions using existing straight pipe fracture prediction analysis methods, and elbow fracture prediction methods developed in this program was performed. This analysis was directed at addressing the concerns regarding the validity of using analysis predictions developed for straight pipe to predict the fracture stresses of cracked elbows. Finally, a simplified fitting flaw acceptance criteria incorporating ASME B2 stress indices and straight pipe, circumferential-crack analysis was developed.

Kilinski, T.; Mohan, R.; Rudland, D.; Fleming, M. [and others

1996-12-01T23:59:59.000Z

413

Cryogenic large bandwidth acoustooptic deflectors  

Science Journals Connector (OSTI)

At high frequencies (~1 GHz) acoustic attenuation severely limits the time aperture of acoustooptic deflectors (AOD). It is shown in this paper that decreasing the...

Fuss, Ian

1987-01-01T23:59:59.000Z

414

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

E-Print Network [OSTI]

of the hydraulic fracture patterns created during the well stimulation process. This work introduces a novel approach to model the hydraulic fractures in a shale reservoir using a stochastic method called random-walk. We see this approach as a beginning step...

Mhiri, Adnene

2014-08-10T23:59:59.000Z

415

Harmonic conversion of large-aperture 1.05-?m laser beams for inertial-confinement fusion research  

Science Journals Connector (OSTI)

To provide high-energy, high-power beams at short wavelengths for inertial-confinement fusion experiments, we routinely convert the 1.05-?m output of the Nova,...

Wegner, P J; Henesian, M A; Speck, D R; Bibeau, C; Ehrlich, R B; Laumann, C W; Lawson, J K; Weiland, T L

1992-01-01T23:59:59.000Z

416

New Results from Observations of Massive Star Formation in the Mid-Infrared with Large Aperture Telescopes  

E-Print Network [OSTI]

Thanks to the high spatial resolution afforded by 8-10m class telescopes, we are beginning to learn that some sources are extended in their mid-infrared emission because of dusty outflows or heated outflow cavity walls. Therefore one must be extremely careful in interpreting the nature of extended mid-infrared sources (i.e. just because it is extended does not automatically mean it is a disk!).

James M. De Buizer

2006-10-18T23:59:59.000Z

417

Discrete Element Model for Simulations of Early-Life Thermal Fracturing Behaviors in Ceramic Nuclear Fuel Pellets  

SciTech Connect (OSTI)

A discrete element Model (DEM) representation of coupled solid mechanics/fracturing and heat conduction processes has been developed and applied to explicitly simulate the random initiations and subsequent propagations of interacting thermal cracks in a ceramic nuclear fuel pellet during initial rise to power and during power cycles. The DEM model clearly predicts realistic early-life crack patterns including both radial cracks and circumferential cracks. Simulation results clearly demonstrate the formation of radial cracks during the initial power rise, and formation of circumferential cracks as the power is ramped down. In these simulations, additional early-life power cycles do not lead to the formation of new thermal cracks. They do, however clearly indicate changes in the apertures of thermal cracks during later power cycles due to thermal expansion and shrinkage. The number of radial cracks increases with increasing power, which is consistent with the experimental observations.

Hai Huang; Ben Spencer; Jason Hales

2014-10-01T23:59:59.000Z

418

Deformation and fracture characteristics of spent Zircaloy fuel cladding  

SciTech Connect (OSTI)

For a better understanding of Zircaloy fuel-rod failure by the pellet-cladding interaction (PCI) phenomenon, a mechanistic study of deformation and fracture behavior of spent power reactor fuel cladding under simulated PCI conditions was conducted. Zircaloy-2 cladding specimens, obtained from fuel assemblies of operating power reactors, were deformed to fracture at 325/sup 0/C by internal gas pressurization in the absence of fission product simulants. Fracture characteristics and microstructures were examined via SEM, TEM, and HVEM. Numerous dislocation tangles and cell structures, observed in TEM specimens of cladding tubes that failed in a ductile manner, were consistent with SEM observations of a limited number of dimples characteristic of microvoid coalescence. A number of brittle-type failures were produced without the influence of fission product simulants. The brittle cracks occurred near the areas compressed by the Swagelok fittings of the internally pressurized tube and propagated from the outer to the inner surface. Since the outer surface was isolated and maintained under a flowing stream of pure helium, it is unlikely that the brittle-type failure was influenced by any fission product traces. SEM fractography of the brittle-type failure revealed a large area of transgranular pseudocleavage with limited areas of ductile fluting, which were similar in appearance to the surfaces produced by in-reactor PCI-type failures. A TEM evaluation of the cladding in the vicinity of the through-wall crack revealed numerous locations that contained an extensive amount of second-phase precipitate (Zr/sub 3/O). We believe that the brittle-type failures of the irradiated spent fuel cladding in the stress rupture experiments are associated with segregation of oxygen, which leads to the formation of the order structure, an immobilization of dislocations, and minimal plastic deformation in the material.

Chung, H.M.; Yaggee, F.L.

1982-09-01T23:59:59.000Z

419

Gamma-ray observations of the Crab Region using a coded-aperture telescope  

SciTech Connect (OSTI)

The region of the Galactic anticenter, including the Crab Nebula, was observed during a balloon flight of the University of New Hampshire Directional Gamma-Ray Telescope employing the coded-aperture imaging technique to image celestial gamma-radiation between 160 keV and 9.3 MeV. The background systematics are treated with a simple and relatively straightforward correction procedure. The results demonstrate that the coded-aperture procedure is a viable approach for imaging not only point sources of radiation, but also extended sources of emission. The results for the Crab's photon spectrum are consistent with a power-law spectrum. Upper limits on the flux levels of line emission at 405 keV and 1050 keV and on the flux from the X-ray binary source A0535 + 26 and diffuse Galactic emission from the anticenter region are derived. 35 references.

Mcconnell, M.L.; Dunphy, P.P.; Forrest, D.J.; Chupp, E.L.; Owens, A.

1987-10-01T23:59:59.000Z

420

Coded aperture imaging system optimized for hard x-ray and gamma ray astronomy  

SciTech Connect (OSTI)

A coded aperture imaging system has been designed for the Gamma-Ray Imaging Spectrometer (GRIS). The system is optimized for imaging 511-keV positron-annihilation photons. For a galactic center 511-keV source strength of 10/sup -3/ cm/sup -2/s/sup -1/, the source location accuracy is expected to be +-0.2/sup 0/.

Gehrels, N.; Cline, T.L.; Huters, A.F.; Leventhal, M.; MacCallum, C.J.; Reber, J.D.; Stang, P.D.; Teegarden, B.J.; Tueller, J.

1985-01-01T23:59:59.000Z

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


421

RF/optical shared aperture for high availability wideband communication RF/FSO links  

SciTech Connect (OSTI)

An RF/Optical shared aperture is capable of transmitting and receiving optical signals and RF signals simultaneously. This technology enables compact wide bandwidth communications systems with 100% availability in clear air turbulence, rain and fog. The functions of an optical telescope and an RF reflector antenna are combined into a single compact package by installing an RF feed at either of the focal points of a modified Gregorian telescope.

Ruggiero, Anthony J; Pao, Hsueh-yuan; Sargis, Paul

2014-04-29T23:59:59.000Z

422

High precision ultrasonic scanning system and SAFT-UT (synthetic aperture technique) development  

SciTech Connect (OSTI)

The NDT divisions at SNLA are continually striving to anticipate customer requests by adding advanced test facilities. This paper describes a new ultrasonic testing system being developed in Albuquerque to provide precise scanning of smaller test objects. There are two major subsystems that make-up the ultrasonic testing system, a high precision scanner/digitizer and a real-time processing system which automates the synthetic aperture focusing technique. These subsystems are described in the following sections.

Shurtleff, W.W.

1987-06-01T23:59:59.000Z

423

Remote optical sensing on the nanometer scale with a bowtie aperture nano-antenna on a SNOM fiber tip  

E-Print Network [OSTI]

Plasmonic nano-antennas have proven the outstanding ability of sensing chemical and physical processes down to the nano-meter scale. Sensing is usually achieved within the highly confined optical fields generated resonantly by the nano-antennas, i.e. in contact to the nano-structures. In these paper, We demonstrate the sensing capability of nano-antennas to their larger scale environment, well beyond their plasmonic confinement volume, leading to the concept of 'remote' (non contact) sensing on the nano-meter scale. On the basis of a bowtie-aperture nano-antenna (BNA) integrated at the apex of a SNOM fiber tip, we introduce an ultra-compact, move-able and background-free optical nano-sensor for the remote sensing of a silicon surface (up to distance of 300 nm). Sensitivity of the BNA to its large scale environment is high enough to expect the monitoring and control of the spacing between the nano-antenna and a silicon surface with sub-nano-meter accuracy. This work paves the way towards a new class of nano-po...

Atie, Elie M; Eter, Ali El; Salut, Roland; Nedeljkovic, Dusan; Tannous, Tony; Baida, Fadi I; Grosjean, Thierry

2015-01-01T23:59:59.000Z

424

Fracture Characterization Technologies | Open Energy Information  

Open Energy Info (EERE)

Fracture Characterization Technologies Fracture Characterization Technologies Jump to: navigation, search Geothermal ARRA Funded Projects for Fracture Characterization Technologies Loading map... {"format":"googlemaps3","type":"ROADMAP","types":["ROADMAP","SATELLITE","HYBRID","TERRAIN"],"limit":200,"offset":0,"link":"all","sort":[""],"order":[],"headers":"show","mainlabel":"","intro":"","outro":"","searchlabel":"\u2026 further results","default":"","geoservice":"google","zoom":false,"width":"600px","height":"350px","centre":false,"layers":[],"controls":["pan","zoom","type","scale","streetview"],"zoomstyle":"DEFAULT","typestyle":"DEFAULT","autoinfowindows":false,"kml":[],"gkml":[],"fusiontables":[],"resizable":false,"tilt":0,"kmlrezoom":false,"poi":true,"imageoverlays":[],"markercluster":false,"searchmarkers":"","icon":"","visitedicon":"","forceshow":true,"showtitle":true,"hidenamespace":false,"template":false,"title":"","label":"","lines":[],"polygons":[],"circles":[],"rectangles":[],"locations":[{"text":"

425

Design of a near-field coded aperture cameras for high-resolution medical and industrial gamma-ray imaging  

E-Print Network [OSTI]

Coded Aperture Imaging is a technique originally developed for X-ray astronomy, where typical imaging problems are characterized by far-field geometry and an object made of point sources distributed over a mainly dark ...

Accorsi, Roberto, 1971-

2001-01-01T23:59:59.000Z

426

Assessment of radial image distortion and spherical aberration on three-dimensional synthetic aperture particle image velocimetry measurements  

E-Print Network [OSTI]

This thesis presents a numerical study of the effects of radial image distortion and spherical aberration on reconstruction quality of synthetic aperture particle image velocimetry (SAPIV) measurements. A simulated SAPIV ...

Kubaczyk, Daniel Mark

2013-01-01T23:59:59.000Z

427

Manual and Semiautomated Wind Direction Editing for Use in the Generation of Synthetic Aperture Radar Wind Speed Imagery  

Science Journals Connector (OSTI)

Previous studies have demonstrated that satellite synthetic aperture radar (SAR) can be used as an accurate scatterometer, yielding wind speed fields with subkilometer resolution. This wind speed generation is only possible, however, if a ...

George S. Young; Todd D. Sikora; Nathaniel S. Winstead

2007-06-01T23:59:59.000Z

428

Effects of subsurface fracture interactions on surface deformation  

E-Print Network [OSTI]

Although the surface deformation resulting from the opening of a single fracture in a layered elastic half-space resembles the observed deformation at the InSalah site, it seems unlikely that only a single fracture is ...

Jerry, Ruel (Ruel Valentine)

2013-01-01T23:59:59.000Z

429

Experimental Study of Acid Fracture Conductivity of Austin Chalk Formation  

E-Print Network [OSTI]

Acid fracture conductivity and the effect of key variables in the etching process during acid fracturing can be assessed at the laboratory scale. This is accomplished by using an experimental apparatus that simulates acid injection fluxes comparable...

Nino Penaloza, Andrea

2013-05-01T23:59:59.000Z

430

Development and testing of an advanced acid fracture conductivity apparatus  

E-Print Network [OSTI]

wells. Acid fracturing is a standard practice to increase the production rate and to improve ultimate recovery in carbonate reservoirs. There have been successful cases in most carbonate reservoirs around the world. However acid fracture performance...

Zou, ChunLei

2006-08-16T23:59:59.000Z

431

How can we use one fracture to locate another?  

E-Print Network [OSTI]

Hydraulic fracturing is an important tool that helps extract fluids from the subsurface. It is critical in applications ranging from enhanced oil recovery to geothermal energy pro-duction. As the goal of fracturing is to ...

Poliannikov, Oleg V.

2011-01-01T23:59:59.000Z

432

Effectiveness of microseismic monitoring for optimizing hydraulic fracturing in California  

E-Print Network [OSTI]

Hydraulic fracturing has fundamentally changed the oil and gas industry in the past 10 years. Bakersfield, California provides a unique case study because steam injection, a type of hydraulic fracturing, has been used there ...

Alampi, Ann M

2014-01-01T23:59:59.000Z

433

On equivalence of thinning fluids used for hydraulic fracturing  

E-Print Network [OSTI]

The paper aims to answer the question: if and how non-Newtonian fluids may be compared in their mechanical action when used for hydraulic fracturing? By employing the modified formulation of the PKN problem we obtain its simple analytical solutions in the cases of perfectly plastic and Newtonian fluids. Since the results for shear thinning fluids are intermediate between those for these cases, the obtained equation for the fracture length suggests a criterion of the equivalence of various shear thinning fluids for the problem of hydraulic fractures. We assume fluids equivalent in their hydrofracturing action, when at a reference time they produce fractures of the same length. The equation for the fracture length translates the equivalence in terms of the hydraulic fracture length and treatment time into the equivalence in terms of the properties of a fracturing fluid (behavior and consistency indices). Analysis shows that the influence of the consistency and behavior indices on the fracture length, particle v...

Linkov, Alexander

2012-01-01T23:59:59.000Z

434

Hydraulic Fracture Monitoring: A Jonah Field Case Study  

E-Print Network [OSTI]

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 ...

Seher, T.

2011-01-01T23:59:59.000Z

435

Seismic characterization of fractured reservoirs by focusing Gaussian beams  

E-Print Network [OSTI]

Naturally fractured reservoirs occur worldwide, and they account for the bulk of global oil production. The most important impact of fractures is their influence on fluid flow. To maximize oil production, the characterization ...

Zheng, Yingcai

436

A Bayesian framework for fracture characterization from surface seismic data  

E-Print Network [OSTI]

We describe a methodology for quantitatively characterizing the fractured nature of a hydrocarbon or geothermal reservoir from surface seismic data under a Bayesian inference framework. Fractures provide pathways for fluid ...

Zamanian, S. Ahmad

2012-01-01T23:59:59.000Z

437

Fracture Evolution Following a Hydraulic Stimulation within an EGS Reservoir  

Broader source: Energy.gov [DOE]

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

438

Fracture Characterization from Scattered Energy: A Case Study  

E-Print Network [OSTI]

We use 3D surface seismic data to determine the presence and the preferred orientation of fracture corridors in a field. The Scattering Index method is proving to be a robust tool for detecting and mapping fracture corridors. ...

Grandi, Samantha K.

2006-01-01T23:59:59.000Z

439

Incorporating Rigorous Height Determination into Unified Fracture Design  

E-Print Network [OSTI]

; height, length and width. Unified fracture design (UFD) offers a method to determine the fracture dimensions providing the maximum productivity index for a specific proppant amount. Then, in order to achieve the maximum productivity index, the treatment...

Pitakbunkate, Termpan

2010-10-12T23:59:59.000Z

440

Fracture and hydrology data from field studies at Stripa, Sweden  

SciTech Connect (OSTI)

The purpose of this report is to present the basic fracture and hydrology data collected as part of the joint LBL-KBS fracture hydrology program at Stripa, Sweden. A detailed description of the fracture-core logging and hydrology borehole testing procedures is included as well as a description of how the fracture and hydrology data were coded and organized. Based on this coding a series of computer data files for the fracture and hydrology borehole data have been constructed and these are described in detail. The fracture data file for one borehole is presented as an example in an appendix along with all of the raw and some partially processed and analyzed fracture hydrology data files. A detailed description of how this data will be analyzed to develop a thorough understanding of the fracture system and hydrogeologic characteristics of the Stripa site is presented.

Gale, J.E.

1981-04-01T23:59:59.000Z

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


441

Finite Difference Modeling of Seismic Responses to Intersecting Fracture Sets  

E-Print Network [OSTI]

Fractured reservoir characterization is becoming increasingly important for the petroleum industry. Currentmethods for this task are developed based on effectivemedia theory, which assumes the cracks or fractures in a ...

Chi, Shihong

2006-01-01T23:59:59.000Z

442

Compartmentalization analysis using discrete fracture network models  

SciTech Connect (OSTI)

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

La Pointe, P.R.; Eiben, T.; Dershowitz, W. [Golder Associates Inc., Redmond, WA (United States); Wadleigh, E. [Marathon Oil Company, Midland, TX (United States). Mid-Continent Region Production

1997-12-31T23:59:59.000Z

443

HFIR vessel probabilistic fracture mechanics analysis  

SciTech Connect (OSTI)

The life of the High Flux Isotope Reactor (HFIR) pressure vessel is limited by a radiation induced reduction in the material`s fracture toughness. Hydrostatic proof testing and probabilistic fracture mechanics analyses are being used to meet the intent of the ASME Code, while extending the life of the vessel well beyond its original design value. The most recent probabilistic evaluation is more precise and accounts for the effects of gamma as well as neutron radiation embrittlement. This analysis confirms the earlier estimates of a permissible vessel lifetime of at least 50 EFPY (100 MW).

Cheverton, R.D. [Delta-21 Resources, Inc., Oak Ridge, TN (United States); Dickson, T.L. [Oak Ridge National Lab., TN (United States)

1997-01-01T23:59:59.000Z

444

Compartmentalization analysis using discrete fracture network models  

SciTech Connect (OSTI)

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

La Pointe, P.R.; Eiben, T.; Dershowitz, W. [Golder Associates, Redmond, VA (United States); Wadleigh, E. [Marathon Oil Co., Midland, TX (United States)

1997-08-01T23:59:59.000Z

445

Application of a 3D hydraulic-fracturing simulator for design of acid-fracturing treatments  

SciTech Connect (OSTI)

Field experience during 1989--90 shows that application of a 3D hydraulic-fracturing simulator increases success of acid-fracturing well treatments. Fracture extension can be limited to the oil-bearing pay, maximum lateral extension can be realized within the height constraint, and acid/rock contact time can be increased by a factor of between 3 and 30. Oil-production response can be improved over other stimulation designs while water-production response can be limited. These methods have been applied in mature waterfloods of the Permian Basin and Cedar Creek anticline.

Morgenthaler, L.N. (Shell Development Co., Houston, TX (United States))

1994-02-01T23:59:59.000Z

446

Experimental and Analytical Research on Fracture Processes in ROck  

SciTech Connect (OSTI)

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

Herbert H.. Einstein; Jay Miller; Bruno Silva

2009-02-27T23:59:59.000Z

447

Methodologies and new user interfaces to optimize hydraulic fracturing design and evaluate fracturing performance for gas wells  

E-Print Network [OSTI]

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 the treatment parameters...

Wang, Wenxin

2006-04-12T23:59:59.000Z

448

Colloid-facilitated radionuclide transport in fractured porous rock  

E-Print Network [OSTI]

radionuclide on the fracture surface [kg ? nuclide / m' - surface]. 23 3. 4 The Radionuclide transport in the aqueous phase within the fracture The radionuclide transport in the aqueous phase within the fracture is expressed as: BN cf rr r ? +V J +VV...

Baek, Inseok

2012-06-07T23:59:59.000Z

449

Creation and Impairment of Hydraulic Fracture Conductivity in Shale Formations  

E-Print Network [OSTI]

Multi-stage hydraulic fracturing is the key to the success of many shale gas and shale oil reservoirs. The main objectives of hydraulic fracturing in shale are to create artificial fracture networks that are conductive for oil and gas flow...

Zhang, Junjing

2014-07-10T23:59:59.000Z

450

Estimating Major and Minor Natural Fracture Patterns in Gas  

E-Print Network [OSTI]

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

Mohaghegh, Shahab

451

Notch Sensitivity of Ceramic Composites with Rising Fracture Resistance  

E-Print Network [OSTI]

of common notched test configurations with the material's fracture resistance. Analogous treatments of notch sensitivity have been used previously for other materials that exhibit rising fracture resistance, includingNotch Sensitivity of Ceramic Composites with Rising Fracture Resistance Michael A. Mattoni

Zok, Frank

452

New fluids help increase effectiveness of hydraulic fracturing  

SciTech Connect (OSTI)

It is important to choose the most effective fluid for hydraulic fracturing a particular formation. Fracturing fluids are used to initiate formation parting, extend the fracture into the reservoir, and to transport and distribute proppant. This paper discusses the fundamental of fluid types, viscosifiers, and fluid rheology.

Ebinger, C.D.; Hunt, E.

1989-06-05T23:59:59.000Z

453

HYDRAULIC STIMULATION OF NATURAL FRACTURES AS REVEALED BY INDUCED MICROEARTHQUAKES,  

E-Print Network [OSTI]

-1- HYDRAULIC STIMULATION OF NATURAL FRACTURES AS REVEALED BY INDUCED MICROEARTHQUAKES, CARTHAGE, December, 2001 Manuscript # 01066 LAUR# 01-1204 #12;Hydraulic Stimulation of Natural Fractures -2- ABSTRACT We have produced a high-resolution microseismic image of a hydraulic fracture stimulation

454

Hydraulic Fractures: multiscale phenomena, asymptotic and numerical solutions  

E-Print Network [OSTI]

Hydraulic Fractures: multiscale phenomena, asymptotic and numerical solutions CSIRO CSS TCP Detournay (UMN) Eduard Siebrits (SLB) #12;2 Outline · Examples of hydraulic fractures · Governing equations well stimulation Fracturing Fluid Proppant #12;5 Quarries #12;6 Magma flow Tarkastad #12;7 Model EQ 1

Peirce, Anthony

455

Hydraulic Fractures: multiscale phenomena, asymptotic and numerical solutions  

E-Print Network [OSTI]

Hydraulic Fractures: multiscale phenomena, asymptotic and numerical solutions SANUM Conference (UMN) Eduard Siebrits (SLB) #12;2 Outline · Examples of hydraulic fractures · Governing equations well stimulation Fracturing Fluid Proppant #12;5 Quarries #12;6 Magma flow Tarkastad #12;7 Model EQ 1

Peirce, Anthony

456

Modeling Turbulent Hydraulic Fracture Near a Free Surface  

E-Print Network [OSTI]

Modeling Turbulent Hydraulic Fracture Near a Free Surface Victor C. Tsai Seismological Laboratory consider a hydraulic fracture problem in which the crack grows parallel to a free surface, subject to fully components. ^· Non-dimensionalized ·. 1 Introduction Hydraulic fracture has been studied for many years

457

Role of seepage forces on hydraulic fracturing and failure patterns  

E-Print Network [OSTI]

Role of seepage forces on hydraulic fracturing and failure patterns Alexander Rozhko Thesis September 2007 #12;ii Role of seepage forces on hydraulic fracturing and failure patterns Abstract. The mechanical role of seepage forces on hydraulic fracturing and failure patterns was studied both

Paris-Sud XI, Université de

458

Modeling Turbulent Hydraulic Fracture Near a Free Surface  

E-Print Network [OSTI]

Modeling Turbulent Hydraulic Fracture Near a Free Surface Victor C. Tsai Seismological Laboratory consider a hydraulic fracture problem in which the crack grows parallel to a free surface, subject to fully components. wall Wall shear stress. ^· Non-dimensionalized ·. 1 Introduction Hydraulic fracture has been

459

CLEAVAGE FRACTURE MICROMECHANISMS RELATED TO WPS EFFECT IN RPV STEEL  

E-Print Network [OSTI]

CLEAVAGE FRACTURE MICROMECHANISMS RELATED TO WPS EFFECT IN RPV STEEL S. R. Bordet1 , B. Tanguy1 , S by warm pre-stress (WPS) on the cleavage fracture micromechanisms of a 18MND5 (A533B) reactor pressure vessel (RPV) steel. In this purpose, different WPS fracture test results obtained on compact tensile (CT

Boyer, Edmond

460

Introduction Fracture at small length scales is a concern  

E-Print Network [OSTI]

Introduction Fracture at small length scales is a concern in many advanced technologies. Micro. These constrained geometries localize cracking so that fracture may not compromise the structural integrity functions. For example, lo- calized fracture of a dielectric film adjacent to a conducting line

Suo, Zhigang

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


461

Scaling of fracture length and distributed damage Vladimir Lyakhovsky  

E-Print Network [OSTI]

Scaling of fracture length and distributed damage Vladimir Lyakhovsky The Institute of Earth space scaling except linear relations between fracture length and displacements and thus the determination theoretically of the strength of a body or structure directly. Self-similarity of a fracture

Lyakhovsky, Vladimir

462

Fracture patterns in thin films and multilayers Alex A. Volinsky  

E-Print Network [OSTI]

Fracture patterns in thin films and multilayers Alex A. Volinsky University of South Florida, excessive residual and externally applied stresses cause film fracture. In the case of tensile stress is the key for causing thin film fracture, either in tension, or compression, it is the influence

Volinsky, Alex A.

463

Monitoring of Fracture Cri0cal Steel Bridges  

E-Print Network [OSTI]

#12;Monitoring of Fracture Cri0cal Steel Bridges: Acous0c Emission Sensors Fracture System Needs to Iden0fy: · Crack Ini0a0on · Crack Propaga0on · Weld Fracture Advanced Warning of Structural Distress #12;Technology Selec0on: Acous0c

Minnesota, University of

464

Structured Deformations as Energy Minimizers in Models of Fracture and  

E-Print Network [OSTI]

Structured Deformations as Energy Minimizers in Models of Fracture and Hysteresis R. Choksi and for a bar experiencing both smooth exten- sion and macroscopic fractures then are determined, and applications to the shearing of single crystals and to the cohesive fracture of solids are discussed. Yield

465

Automatic Fracture Reduction Thomas Albrecht and Thomas Vetter  

E-Print Network [OSTI]

Automatic Fracture Reduction Thomas Albrecht and Thomas Vetter University of Basel Abstract. We segmented from CT scans. The result of this virtual fracture reduction is intended to be used an operation plan. We propose to achieve automatic fracture reduction by fitting the bone fragments

Vetter, Thomas

466

Geometric fracture modeling in BOLT Jeffrey Hellrung1  

E-Print Network [OSTI]

Geometric fracture modeling in BOLT Jeffrey Hellrung1 Andrew Selle2 Arthur Shek2 Eftychios Sifakis1 from the un-fractured model. 2 Crack geometry generation The input to our system consists of a closed triangulated surface defining the (uncut) solid object to be fractured and one or more ad- ditional

Liblit, Ben

467

Fracture Toughness of MDF and other Materials with Fiber Bridging  

E-Print Network [OSTI]

Fracture Toughness of MDF and other Materials with Fiber Bridging Noah Matsumoto and John A. Nairn* ABSTRACT We measured the fracture toughness of MDF panels with two different densities by using crack propagation experiments and energy-based fracture mechanics. The two challenges were to identify the energy

Nairn, John A.

468

EXPERIMENTAL INVESTIGATION OF BOILING HEAT CONVECTION IN A FRACTURE  

E-Print Network [OSTI]

EXPERIMENTAL INVESTIGATION OF BOILING HEAT CONVECTION IN A FRACTURE A REPORT SUBMITTED between heat conduction and heat convection with boiling flow in a rock fracture. An experimental coefficient. This coefficient is the proportionality factor between the heat flux to a fracture surface

Stanford University

469

SCALING OF FRACTURE SYSTEMS IN GEOLOGICAL MEDIA E. Bonnet,1  

E-Print Network [OSTI]

SCALING OF FRACTURE SYSTEMS IN GEOLOGICAL MEDIA E. Bonnet,1 O. Bour,2 N. E. Odling,1,3 P. Davy,2 I. Main,4 P. Cowie,4 and B. Berkowitz5 Abstract. Scaling in fracture systems has become an active field spread widely through the literature. Although it is rec- ognized that some fracture systems are best

Cowie, Patience

470

Fibre Based Modeling of Wood Dynamics and Fracture  

E-Print Network [OSTI]

Fibre Based Modeling of Wood Dynamics and Fracture by Sean Meiji Sutherland B.Sc., The University for the simulation of the dynamics and fracturing char- acteristics of wood, specifically its anisotropic behaviour bundles of fibres. Additionally, we describe the conditions under which fracture occurs in the material

Bridson, Robert

471

In vitro fracture toughness of human dentin V. Imbeni,1  

E-Print Network [OSTI]

In vitro fracture toughness of human dentin V. Imbeni,1 R. K. Nalla,1 C. Bosi,1 J. H. Kinney,2 R. O August 2002 Abstract: The in vitro fracture toughness of human dentin has been reported measured crit- ical stress intensity, Kc, for the onset of unstable fracture along an orientation

Ritchie, Robert

472

Fracture surface energy of the Punchbowl fault, San Andreas system  

E-Print Network [OSTI]

Fracture surface energy of the Punchbowl fault, San Andreas system Judith S. Chester1 , Frederick M. Chester1 & Andreas K. Kronenberg1 Fracture energy is a form of latent heat required to create weakening1­3 . Fracture energy has been estimated from seismological and experimental rock deformation data4

Chester, Frederick M.

473

THE EFFECT OF SURFACE TENSION IN MODELING INTERFACIAL FRACTURE  

E-Print Network [OSTI]

THE EFFECT OF SURFACE TENSION IN MODELING INTERFACIAL FRACTURE By Tsvetanka Sendova and Jay R Fracture Tsvetanka Sendova and Jay R. Walton Institute for Mathematics and Its Applications, University@math.tamu.edu Abstract. In this article the problem of an interface fracture between two isotropic linear elas- tic

474

The use of seismic anisotropy for characterizing subsurface fracture ori-  

E-Print Network [OSTI]

The use of seismic anisotropy for characterizing subsurface fracture ori- entations and intensity anisotropy as a routine technique for fracture characterization is partly because of its inability to pro- vide information about sizes and vol- ume of fractures. Although both grain-scale micro

Edinburgh, University of

475

6. Fracture mechanics lead author: J, R. Rice  

E-Print Network [OSTI]

6. Fracture mechanics lead author: J, R. Rice Division of Applied Sciences, Harvard University. F. Shih, and the ASME/AMD Technical Committee on Fracture Mechanics, pro- vided by A. S. Argon, S. N, W. D. Stuart, and R. Thomson. 6.0 ABSTRACT Fracture mechanics is an active research field

476

Femoral neck fracture prediction by anisotropic yield criteria  

E-Print Network [OSTI]

Femoral neck fracture prediction by anisotropic yield criteria M. Tellache a , b , M. Pithioux and increases its porosity. Hip fractures are the more recurrent consequences of osteoporosis, and are the cause of morbidity and increase the rate of mortality. The fracture risk due to osteoporosis, is undertaken with Dual

Paris-Sud XI, Université de

477

Geomechanical Development of Fractured Reservoirs During Gas Production  

E-Print Network [OSTI]

for deformation and fluid flow within matrix domain; while the other is the fracture element simulating the fluid flow only through the fractures. Both matrix and fractures are assumed to be permeable and can accomodate fluid transported. A quasi steady-state...

Huang, Jian

2013-04-05T23:59:59.000Z

478

Diagnosis and evaluation of fracturing treatments  

SciTech Connect (OSTI)

This paper introduces the pressure derivative in fracturing-pressure analysis for oil wells. The derivative is shown to enhance the analysis capabilities significantly. The interpretation methodology is presented, and several field data sets and simulations are discussed to illustrate to technique.

Barree, R.D. (Marathon Oil Co. (US)); Ayoub, J.A.; Brown, J.E.; Elphick, J.J. (Dowell Schlumberger (US))

1992-02-01T23:59:59.000Z

479

Boiling Radial Flow in Fractures of Varying  

E-Print Network [OSTI]

the surface, within the matrix. The depth of boiling was a function of injection rate, thermal power supplied coupled to injection rate into the fracture. However, for porous surfaces, heat flux, and associated values of excess temperature and a boiling convection coefficient exhibited variation with injection rate

Stanford University

480

Interference Fracturing: Non-Uniform Distributions of Perforation Clusters that Promote Simultaneous Growth of Multiple Hydraulic Fractures  

E-Print Network [OSTI]

Simultaneous Growth of Multiple Hydraulic Fractures A.P. Peirce, University of British Columbia and A.P. Bunger in horizontal well stimulation is the generation of hydraulic fractures (HFs) from all perforation clusters shadowing" that refers to suppression of some hydraulic fractures by the compressive stresses exerted

Peirce, Anthony

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


481

Microseismicity, stress, and fracture in the Coso geothermal field,  

Open Energy Info (EERE)

Microseismicity, stress, and fracture in the Coso geothermal field, Microseismicity, stress, and fracture in the Coso geothermal field, California Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Journal Article: Microseismicity, stress, and fracture in the Coso geothermal field, California Details Activities (1) Areas (1) Regions (0) Abstract: Microseismicity, stress, and fracture in the Coso geothermal field are investigated using seismicity, focal mechanisms and stress analysis. Comparison of hypocenters of microearthquakes with locations of development wells indicates that microseismic activity has increased since the commencement of fluid injection and circulation. Microearthquakes in the geothermal field are proposed as indicators of shear fracturing associated with fluid injection and circulation along major pre-existing

482

Advanced Characterization of Fractured Reservoirs in Carbonate Rocks: The Michigan Basin  

SciTech Connect (OSTI)

The purpose of the study was to collect and analyze existing data on the Michigan Basin for fracture patterns on scales ranging form thin section to basin. The data acquisition phase has been successfully concluded with the compilation of several large digital databases containing nearly all the existing information on formation tops, lithology and hydrocarbon production over the entire Michigan Basin. These databases represent the cumulative result of over 80 years of drilling and exploration.

Wood, James R.; Harrison, William B.

2002-12-02T23:59:59.000Z

483

Tune modulation due to synchrotron oscillations and chromaticity, and the dynamic aperture  

SciTech Connect (OSTI)

A tracking study was done of the effects of a tune modulation, due to synchrotron oscillations and the tune dependence on momentum (chromaticity), on the dynamic aperture. The studies were done using several RHIC lattices and tracking runs of about 1 {times} 10{sup 6} turns. The dynamic aperture was found to decrease roughly linearly with the amplitude of the tune modulation and may be represented by A = A{sub o}(l--10 {Delta}{nu}) where A{sub o} is the dynamic aperture for {Delta}{nu} = 0, and {Delta}{nu} is the tune modulation amplitude. In Eq. (1), the range of {Delta}{nu} is such that lower order non-linear resonances, like the 1/3 and 1/4 resonance axe not crossed because of the tune modulation. Three different cases were studied, corresponding to RHIC lattices with different {beta}*, and with different synchrotron oscillation amplitudes. In each case, the tune modulation amplitude was varied by changing the chromaticity. In each case, roughly the same result, Eq. (1), was found. The result found here for the effect of a tune modulation due to chromaticity may be compared with the result found for the effect of a tune modulation due to a gradient ripple in the quadrupoles, which was A = A{sub o}(l--42 {Delta}{nu}). The effect of a {Delta}{nu} due to a gradient ripple appears to be about 4 times stronger than the effect of a {Delta}{nu} due to chromaticity and synchrotron oscillations.

Parzen, G.

1994-03-01T23:59:59.000Z

484

Characterization of Fractures in Geothermal Reservoirs Using Resistivity |  

Open Energy Info (EERE)

Characterization of Fractures in Geothermal Reservoirs Using Resistivity Characterization of Fractures in Geothermal Reservoirs Using Resistivity Jump to: navigation, search OpenEI Reference LibraryAdd to library Conference Paper: Characterization of Fractures in Geothermal Reservoirs Using Resistivity Abstract The optimal design of production in fractured geothermal reservoirs requires knowledge of the resource's connectivity, therefore making fracture characterization highly important. This study aims to develop methodologies to use resistivity measurements to infer fracture properties in geothermal fields. The resistivity distribution in the field can be estimated by measuring potential differences between various points and the data can then be used to infer fracture properties due to the contrast in resistivity between water and rock.

485

Advanced hydraulic fracturing methods to create in situ reactive barriers  

SciTech Connect (OSTI)

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

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

1997-12-31T23:59:59.000Z

486

Hydraulic fracturing in a sedimentary geothermal reservoir: Results and implications  

Science Journals Connector (OSTI)

Field experiments in a geothermal research well were conducted to enhance the inflow performance of a clastic sedimentary reservoir section. Due to depths exceeding 4050 m, bottom hole temperatures exceeding 140 °C, and open hole section (dual zone), technically demanding and somewhat unprecedented conditions had to be managed. The fracturing operations were successful. Fractures were created in two isolated borehole intervals and the inflow behaviour of the reservoir was decisively enhanced. The effective pressures applied for fracture initiation and propagation were only slightly above in situ pore pressures. Nevertheless, the stimulation ratio predicted by fracture performance modelling could not be achieved. Multiple reasons could be identified that account for the mismatch. An insufficient fracture tie-back, as well as chemical and mechanical processes during closure, led to reduced fracture conductivities and therefore diminished productivity. The insights gained are the basis for further fracture design concepts at the given and geologic comparable sites.

B. Legarth; E. Huenges; G. Zimmermann

2005-01-01T23:59:59.000Z

487

Ion funnel with extended mass range and reduced conductance limit aperture  

DOE Patents [OSTI]

An improved ion funnel design is disclosed that decreases the axial RF (parasite) fields at the ion funnel exit. This is achieved by addition of one or more compensation electrodes after the conductance limit electrode. Various RF voltage profiles may be applied to the various electrodes minimizing the parasite axial potential wells. The smallest RF aperture that serves as the conductance limiting electrode is further reduced over standard designs. Overall, the ion funnel improves transmission ranges of both low m/z and high m/z ions, reducing RF activation of ions and decreasing the gas load to subsequent differential pumping stages.

Tolmachev, Aleksey V. (Richland, WA); Smith, Richard D. (Richland, WA)

2008-04-01T23:59:59.000Z

488

A novel synthetic aperture technique for breast tomography with toroidal arrays  

SciTech Connect (OSTI)

Ultrasound is commonly used as an adjunct to mammography for diagnostic evaluation of suspicions arising from breast cancer screening. As an alternative to conventional sonography that uses hand-held transducers, toroidal array probes that encircle the breast immersed in a water bath have been investigated for ultrasound tomography. This paper introduces a new method for three-dimensional synthetic aperture diffraction tomography that maximizes the resolution in the scanning direction and provides quantitative reconstructions of the acoustic properties of the object. The method is validated by means of numerical simulations.

Huang, Lianjie [Los Alamos National Laboratory; Simonetti, Francesco [IMPERIAL COLLEGE

2009-01-01T23:59:59.000Z

489

Fracture detection using crosshole surveys and reverse vertical seismic profiles at the Conoco Borehole Test Facility, Oklahoma  

Science Journals Connector (OSTI)

......profiles at the Conoco Borehole Test Facility, Oklahoma...RVSPs) at the Conoco Borehole Test Facility, Oklahoma...than 50 m, suggest large fracture densities...granite, Scientific Drilling, 1, 21-26. Crampin...system at the Conoco Borehole Test Facility, Kay......

Enru Liu; Stuart Crampin; John H. Queen

1991-12-01T23:59:59.000Z

490

Fracture simulation for zirconia toughened alumina microstructure  

E-Print Network [OSTI]

Purpose - The purpose of this paper is to describe finite element modelling for fracture and fatigue behaviour of zirconia toughened alumina microstructures. Design/methodology/approach - A two-dimensional finite element model is developed with an actual $Al{_2}O{_3}$ - 10 vol% $ZrO{_2}$ microstructure. A bilinear, time-independent cohesive zone law is implemented for describing fracture behaviour of grain boundaries. Simulation conditions are similar to those found at contact between a head and a cup of hip prosthesis. Residual stresses arisen from the mismatch of thermal coefficient between grains are determined. Then, effects of a micro-void and contact stress magnitude are investigated with models containing residual stresses. For the purpose of simulating fatigue behaviour, cyclic loadings are applied to the models. Findings - Results show that crack density is gradually increased with increasing magnitude of contact stress or number of fatigue cycles. It is also identified that a micro-void brings about...

Kim, Kyungmok; Forest, Bernard

2013-01-01T23:59:59.000Z

491

Naturally fractured tight gas reservoir detection optimization  

SciTech Connect (OSTI)

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.

NONE

1999-06-01T23:59:59.000Z

492

On the convergence of the phase gradient autofocus algorithm for synthetic aperture radar imaging  

SciTech Connect (OSTI)

Synthetic Aperture Radar (SAR) imaging is a class of coherent range and Doppler signal processing techniques applied to remote sensing. The aperture is synthesized by recording and processing coherent signals at known positions along the flight path. Demands for greater image resolution put an extreme burden on requirements for inertial measurement units that are used to maintain accurate pulse-to-pulse position information. The recently developed Phase Gradient Autofocus algorithm relieves this burden by taking a data-driven digital signal processing approach to estimating the range-invariant phase aberrations due to either uncompensated motions of the SAR platform or to atmospheric turbulence. Although the performance of this four-step algorithm has been demonstrated, its convergence has not been modeled mathematically. A new sensitivity study of algorithm performance is a necessary step towards this model. Insights that are significant to the application of this algorithm to both SAR and to other coherent imaging applications are developed. New details on algorithm implementation identify an easily avoided biased phase estimate. A new algorithm for defining support of the point spread function is proposed, which promises to reduce the number of iterations required even for rural scenes with low signal-to-clutter ratios.

Hicks, M.J.

1996-01-01T23:59:59.000Z

493

Tune modulation due to synchrotron oscillations and chromaticity, and the dynamic aperture  

SciTech Connect (OSTI)

A tracking study was done of the effects of a tune modulations, due to synchrotron oscillations and the tune dependence on momentum (chromaticity), on the dynamic aperture. The studies were done using several RHIC lattices and tracking runs of about 1 {times} 10{sup 6} turns. The dynamic aperture was found to decrease roughly linearly with the amplitude of the tune modulation. Lower order non-linear resonances, like the 1/3 and 1/4 resonance are not crossed because of the tune modulation. Three different cases were studied, corresponding to RHIC lattices with different {beta}*, and with different synchrotron oscillation amplitudes. In each case, the tune modulation amplitude was varied by changing the chromaticity. In each case, roughly the same result, was found. The result found here for the effect of a tune modulation due to chromaticity may be compared with the result found for the effect of a tune modulation due to a gradient ripple in the quadrupoles. The effect of a tune modulation due to a gradient ripple appears to be about 4 times stronger than the effect of a tune modulation due to chromaticity and synchrotron oscillations.

Parzen, G.

1995-05-01T23:59:59.000Z

494

How intense quality control improves hydraulic fracturing  

SciTech Connect (OSTI)

Not unlike the subject of Forced Closure, Intense Quality Control is probably misnamed. What actually is discussed in this article is pilot testing of the fracturing fluids actually pumped at in-situ conditions of temperature and shear. Presented here is development of the need for onsite testing, equipment used, shear and viscosity curves from several jobs showing what went wrong that would otherwise not have been known, and a discussion of borate gel fluids.

Ely, J.W. [Ely and Associates, Inc., Houston, TX (United States)

1996-11-01T23:59:59.000Z

495

FRACTURE FAILURE CRITERIA OF SOFC PEN STRUCTURE  

SciTech Connect (OSTI)

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

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

2007-04-30T23:59:59.000Z

496

Determining Ductile Fracture Toughness in Metals  

SciTech Connect (OSTI)

Ductile fracture toughness determination, such as the J-integral versus crack growth resistance (J-R) curve, is a useful tool for evaluating material structural integrity in the presence of pre-existing defects. The J-R curve represents a way to calculate the work (energy) per unit fracture surface area needed to drive the crack growth. A typical J-R curve is shown in Fig. 1 from which the material fracture toughness near the initiation of stable crack growth (Jq) can be derived. In addition, tearing modulus (TR), representing the material resistance to stable crack growth, can be calculated based on the slope of the J-R curve between two exclusion lines (red dashed lines in Fig. 1). Since the introduction of the J-R curve, extensive efforts have been continuously devoted to develop simplified and reliable methods for determining the material J-R curve. This article briefly reviews three widely-used J-R curve test methods in metals, i.e. elastic unloading compliance (EUC), normalization, and direct current potential drop (DCPD). The main difference in these methods relates to the determination of the crack size. More details of performing the J-R curve determination can be found in ASTM standard E1820-11.

Chen, Xiang [ORNL] [ORNL; Nanstad, Randy K [ORNL] [ORNL; Sokolov, Mikhail A [ORNL] [ORNL; Manneschmidt, Eric T [ORNL] [ORNL

2014-01-01T23:59:59.000Z

497

Simultaneous usage of pinhole and penumbral apertures for imaging small scale neutron sources from inertial confinement fusion experiments  

SciTech Connect (OSTI)

Inertial confinement fusion experiments at the National Ignition Facility are designed to understand the basic principles of creating self-sustaining fusion reactions by laser driven compression of deuterium-tritium (DT) filled cryogenic plastic capsules. The neutron imaging diagnostic provides information on the distribution of the central fusion reaction region and the surrounding DT fuel by observing neutron images in two different energy bands for primary (13-17 MeV) and down-scattered (6-12 MeV) neutrons. From this, the final shape and size of the compressed capsule can be estimated and the symmetry of the compression can be inferred. These experiments provide small sources with high yield neutron flux. An aperture design that includes an array of pinholes and penumbral apertures has provided the opportunity to image the same source with two different techniques. This allows for an evaluation of these different aperture designs and reconstruction algorithms.

Guler, N.; Volegov, P.; Danly, C. R.; Grim, G. P.; Merrill, F. E.; Wilde, C. H. [Los Alamos National Laboratory, P.O. Box 1663, Los Alamos, New Mexico 87545 (United States)

2012-10-15T23:59:59.000Z

498

Review and discussion of the development of synthetic aperture focusing technique for ultrasonic testing (SAFT-UT)  

SciTech Connect (OSTI)

The development and capabilities of synthetic aperture focusing techniques for ultrasonic testing (SAFT-UT) are presented. The purpose of SAFT-UT is to produce high-resolution images of the interior of opaque objects. The goal of this work is to develop and implement methods which can be used to detect and to quantify the extent of defects and cracks in critical components of nuclear reactors (pressure vessels, primary piping systems, and nozzles). This report places particular emphasis upon the practical experimental results that have been obtained using SAFT-UT as well as the theoretical background that underlies synthetic aperture focusing. A discussion regarding high-speed and real-time implementations of two- and three-dimensional synthetic aperture focusing is also presented.

Busse, L.J.; Collins, H.D.; Doctor, S.R.

1984-03-01T23:59:59.000Z

499

Fracture toughness of thick section dissimilar electron beam weld joints  

SciTech Connect (OSTI)

Microstructural investigations as well as crack tip opening displacement (CTOD) fracture toughness test based on elastic-plastic fracture mechanics were performed on single pass, full penetration similar and dissimilar electron beam (EB) welds of 40 mm thick 316L type austenitic steel and high alloyed fine tempered martensitic 9Cr 1Mo Nb V (P91 -ASTM A213) steel. The latter modified steel has been developed to fill up the gap between 12Cr steel and austenitic stainless steels with respect to the high temperature properties and better weldability. Furthermore, it shows a small thermal expansion coefficient and is not susceptible to stress corrosion cracking like the austenitic steel. The weldment properties were evaluated by microstructural analysis, microhardness, Charpy V- notch impact, and by newly developed flat microtensile specimens (0.5 mm thick). The dissimilar EB weld metal and HAZ of P91 steel has been shown to be microstructurally and mechanically distinct from both austenitic and martenistic parent metals. The use of microsized rectangular tensile specimens provides unique solution to the problem of the mechanical property determination of the narrow EB weld joint. The HAZ of the 9Cr1Mo steel exhibits extremely poor CTOD toughness properties in as-welded condition at room temperature. The CTOD values obtained were believed to be represent the intrinsic property of this zone, since the distance of the crack tip to the austenitic steel part was too large to receive a stress relaxation effect from low strength side on the crack tip (by accommodating the applied strains in the high toughness, lower strength 316L plate).

Kocak, M.; Junghans, E.

1994-12-31T23:59:59.000Z

500

Regional Analysis And Characterization Of Fractured Aquifers In The  

Open Energy Info (EERE)

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