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Note: This page contains sample records for the topic "improves fracture length" from the National Library of EnergyBeta (NLEBeta).
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1

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

2

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

3

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

4

Fracture resistance of human cortical bone across multiple length-scales at physiological strain rates  

E-Print Network [OSTI]

Fracture resistance of human cortical bone across multiple length-scales at physiological strain Accepted 22 March 2014 Available online 13 April 2014 Keywords: Bone Strain rate Fracture toughness Plasticity X-ray diffraction a b s t r a c t While most fracture-mechanics investigations on bone have been

Ritchie, Robert

5

Determination of the length and compass orientation of hydraulic fractures by pulse testing  

E-Print Network [OSTI]

S3HAIDVHi OIlflVHOAH i0 NOIlVIN3IHO SSVHWOO QNV HlBN31 3Wl iO NOIlVNIWH3l30 DETERMINATION OF THE LENGTH AND COMPASS ORIENTATION OF HYDRAULIC FRACTURES BY PULSE TESTING A Thesis by MADAN MOHAN MANOHAR Approved as to Style and Content by: Wi... liam J. Lee (Ch ai rman of Commi t tee ) Le a M. Je Member) Richard A. Morse (Member) D. Yon Gonten ( d of Department) December 1984 ABSTRACT Determination of the Length and Compass Drientat1on of Hydraulic Fractures by Pulse Testing...

Manohar, Madan Mohan

1984-01-01T23:59:59.000Z

6

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

7

TRANSGENIC COTTON WITH IMPROVED FIBER MICRONAIRE, STRENGTH, AND LENGTH AND  

E-Print Network [OSTI]

483 TRANSGENIC COTTON WITH IMPROVED FIBER MICRONAIRE, STRENGTH, AND LENGTH AND INCREASED FIBER. Keating, N. G. Srinivas, C. Wu and A. S. Holaday Texas Tech University Lubbock, TX G. J. Jividen Cotton Incorporated Raleigh, NC Abstract We set out to use genetic engineering to make cotton crop yield and fiber

Strauss, Richard E.

8

An Improved Probabilistic Fracture Mechanics Model for Pressurized Thermal Shock  

SciTech Connect (OSTI)

This paper provides an overview of an improved probabilistic fracture mechanics (PFM) model used for calculating the conditional probabilities of fracture and failure of a reactor pressure vessel (RPV) subjected to pressurized-thermal-shock (PTS) transients. The updated PFM model incorporates several new features: expanded databases for the fracture toughness properties of RPV steels; statistical representations of the fracture toughness databases developed through application of rigorous mathematical procedures; and capability of generating probability distributions for RPV fracture and failure. The updated PFM model was implemented into the FAVOR fracture mechanics program, developed at Oak Ridge National Laboratory as an applications tool for RPV integrity assessment; an example application of that implementation is discussed herein. Applications of the new PFM model are providing essential input to a probabilistic risk assessment (PRA) process that will establish an improved technical basis for re-assessment of current PTS regulations by the US Nuclear Regulatory Commission (NRC). The methodology described herein should be considered preliminary and subject to revision in the PTS re-evaluation process.

Dickson, T.L.

2001-10-29T23:59:59.000Z

9

Fracturing alliance improves profitability of Lost Hills field  

SciTech Connect (OSTI)

About 2 billion bbl of oil-in-place are present in the massive diatomite deposits of California's Lost Hills field, about 45 miles north-west of Bakersfield, Calif. Massive hydraulic fracturing treatments, 2,500-3,000 lb of proppant/net perforated ft, are an integral part of developing these reserves. An exclusive fracturing alliance initiated in 1990 between Chevron U.S.A. and Schlumberger Dowell has improved profitability of the Los Hills field. the paper describes the geology, the field before 1987, the 1987--90 period when hydraulic fracturing stimulation was found to be very costly, and after 1990 when the alliance was formed. The paper also describes the fracturing fluid, proppants, engineering evaluation, and execution of the job.

Stewart, M. (Schlumberger Dowell, Bakersfield, CA (United States)); Stewart, D. (Chevron U.S.A. Production Co., Houston, TX (United States)); Gaona, M. (Chevron U.S.A. Production Co., Bakersfield, CA (United States))

1994-11-21T23:59:59.000Z

10

Ceramics containing dispersants for improved fracture toughness  

DOE Patents [OSTI]

The invention is a ceramic composition containing a new class of dispersant for hindering crack propagation by means of one or more energy-dissipative mechanisms. The composition is composed of a ceramic matrix with dispersed particles of a transformation-prone rare-earth niobate, tantalate or mixtures of these with each other and/or with a rare-earth vanadate. The dispersants, having a generic composition tRMO.sub.4, where R is a rare-earth element, B is Nb or Ta and O is oxygen, are mixed in powder form with a powder of the matrix ceramic and sintered to produce a ceramic form or body. The crack-hindering mechanisms operates to provide improved performance over a wide range of temperature and operating conditions.

Nevitt, Michael V. (Wheaton, IL); Aldred, Anthony T. (Wheaton, IL); Chan, Sai-Kit (Darien, IL)

1987-01-01T23:59:59.000Z

11

Improved fracture toughness of fire resistant composites through rapid curing.  

E-Print Network [OSTI]

??A study on the effect of material and fracture properties of phenolic composites cured with reduced thermal cycle times. These reductions were achieved using various… (more)

Denmead, Ashley

2012-01-01T23:59:59.000Z

12

Fractal characterization of fracture networks: An improved box-counting technique  

E-Print Network [OSTI]

Fractal characterization of fracture networks: An improved box-counting technique Ankur Roy,1 fracture networks as fractals and estimating their fractal dimensions (D). If this analysis yields a power and r is the box size, then the network is considered to be fractal. However, researchers are divided

Perfect, Ed

13

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

SciTech Connect (OSTI)

This report describes the work performed during the second year of the project, ''Investigating of Efficiency Improvements during CO{sub 2} Injection in Hydraulically and Naturally Fractured Reservoirs.'' 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 less efficient CO{sub 2} flooding in heterogeneous or fracture-dominated reservoirs. To achieve this objective, in this period we concentrated our effort on investigating the effect of CO{sub 2} injection rates in homogeneous and fractured cores on oil recovery and a strategy to mitigate CO{sub 2} bypassing in a fractured core.

David S. Schechter

2004-04-26T23:59:59.000Z

14

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

SciTech Connect (OSTI)

This report describes the work performed during the second year of the project, ''Investigating of Efficiency Improvements during CO{sub 2} Injection in Hydraulically and Naturally Fractured Reservoirs.'' 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 less efficient CO{sub 2} flooding in heterogeneous or fracture-dominated reservoirs. To achieve this objective, in this period we concentrated our effort on modeling the fluid flow in fracture surface, examining the fluid transfer mechanisms and describing the fracture aperture distribution under different overburden pressure using X-ray CT scanner.

David S. Schechter

2003-10-01T23:59:59.000Z

15

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

SciTech Connect (OSTI)

This report describes the work performed during the third year of the project, ''Investigating of Efficiency Improvements during CO{sub 2} Injection in Hydraulically and Naturally Fractured Reservoirs.'' 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, in this period we concentrated our effort on modeling fluid flow through rough fractures and investigating the grid orientation effect in rectangular grid blocks particularly at high mobility ratio as our precursor to use a compositional simulator. We are developing a robust simulator using Voronoi grids to accurately represent natural and induced fractures. We are also verifying the accuracy of the simulation using scaled laboratory experiments to provide a benchmark for our simulation technique. No such simulator currently exists so this capability will represent a major breakthrough in simulation of gas injection in fractured systems. The following sections outline the results that appear in this report.

David S. Schechter

2004-10-10T23:59:59.000Z

16

Improved fracture toughness of carbon fiber composite functionalized with multi walled carbon nanotubes  

E-Print Network [OSTI]

Improved fracture toughness of carbon fiber composite functionalized with multi walled carbon August 2008 A B S T R A C T Woven carbon fiber (CF) laminae are functionalized in situ with carbon nanotubes (CNTs) to test the hypothesis that growing CNTs on CF (i.e., carbon fiber bundles or tow) would

Bennett, Gisele

17

New ceramics containing dispersants for improved fracture toughness  

DOE Patents [OSTI]

The invention is a ceramic composition containing a new class of dispersant for hindering crack propagation by means of one or more energy-dissipative mechanisms. The composition is composed of a ceramic matrix with dispersed particles of a transformation-prone rare-earth niobate, tantalate or mixtures of these with each other and/or with a rare-earth vanadate. The dispersants, having a generic composition tRBO/sub 4/, where R is a rare-earth element, B if Nb or Ta and O is oxygen, are mixed in powder form with a powder of the matrix ceramic and sintered to produce a ceramic form or body. The crack-hindering mechanisms operates to provide improved performance over a wide range of temperature and operating conditions.

Nevitt, M.V.; Aldred, A.T.; Chan, Sai-Kit

1985-07-01T23:59:59.000Z

18

Genetic Improvement of Upper Half Mean Length and Short Fiber Content in Upland Cotton, Gosspium hirsutum  

E-Print Network [OSTI]

) effects and specific combining ability (SCA) effects. A recombinant inbred line (RIL) population was established to determine the narrow sense heritability (h^2) of AFIS short fiber content by weight (SFCw) and lower half mean length (LHML...

Beyer, Benjamin

2012-10-19T23:59:59.000Z

19

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 less efficient CO{sub 2} flooding in heterogeneous or fracture-dominated reservoirs. This report provides results of the second semi-annual technical progress report that consists of three different topics. In the first topic, laboratory experiments were performed on a Berea core to investigate the changes in rock properties and fluid flow under different stress-state conditions. A comparative study of different stress conditions was also conducted to analyze the effect of the various loading systems. The experimental results show that fracture permeability reduces significantly as the stress increases compared to matrix permeability. The hydrostatic and triaxial stresses have greater impacts on permeability reduction compared to applying stress in the uniaxial stress condition. Fracture flow dominates when the applied stress is less, however, the matrix flow rate increases as applied stress increases and dominates at high stress even if the fracture does not heal completely. In the second topic, the preliminary results of static imbibition experiments are presented as a precursor to image the saturation profiles using X-Ray CT scanner. The static and dynamic imbibition experiments have been done previously (Schechter et al, 2002). The imaging of imbibition experiment is underway to track the saturation profiles using X-ray CT scanner. Hence, no more conclusions are drawn from this study at this time. In the last topic, the modeling of fluid flow through a single fracture incorporating the effect of surface roughness is conducted. Fracture permeability is usually estimated by a cubic law that is based on the theory of hydrodynamics for the laminar flow between flat plates. However, the cubic law is too simple to estimate the fracture permeability correctly, because the surface of real fracture is much more complicated and rougher than the surface of flat plate. Several researchers have shown that the flow characteristics of an actual fracture surface would be quite different due to the effect of tortuosity, impact of surface roughness and contact areas. Nonetheless, to date, these efforts have not converged to form a unified definition on the fracture aperture needed in the cubic law. In this study, therefore, we show that the cubic law could still be used to model small-scale and field-scale data as long as it is modeled effectively, accounting for the effect of surface roughness associated with the fracture surface. The goal of this research is to examine the effect of surface roughness for flow through fractures and to effectively incorporate them into simulations with the aid of geostatistics. Since the research has been supported with experimental results, the consistency of the results enabled us to define a methodology for single fracture simulation. This methodology successfully modeled the slow rate and pressure drop from fractured core experiments, which were earlier not possible through parallel plate approach. Observations suggest that the fracture aperture needs to be distributed to accurately model the experimental results. The effect of friction and tortuosity due to surface roughness needs to be taken into account while modeling.

David S. Schechter

2002-10-30T23:59:59.000Z

20

Investigation of Efficiency Improvements During CO2 Injection in Hydraulically and Naturally Fractured Reservoirs  

SciTech Connect (OSTI)

The objective of this project was 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 less efficient CO2 flooding in heterogeneous or fracture-dominated reservoirs. This report provided results of the second semi-annual technical progress report that consists of three different topics.

Schechter, David S.; Vance, Harold

2003-03-10T23:59:59.000Z

Note: This page contains sample records for the topic "improves fracture length" 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

Using microstructure observations to quantify fracture properties and improve reservoir simulations. Final report, September 1998  

SciTech Connect (OSTI)

The research for this project provides new technology to understand and successfully characterize, predict, and simulate reservoir-scale fractures. Such fractures have worldwide importance because of their influence on successful extraction of resources. The scope of this project includes creation and testing of new methods to measure, interpret, and simulate reservoir fractures that overcome the challenge of inadequate sampling. The key to these methods is the use of microstructures as guides to the attributes of the large fractures that control reservoir behavior. One accomplishment of the project research is a demonstration that these microstructures can be reliably and inexpensively sampled. Specific goals of this project were to: create and test new methods of measuring attributes of reservoir-scale fractures, particularly as fluid conduits, and test the methods on samples from reservoirs; extrapolate structural attributes to the reservoir scale through rigorous mathematical techniques and help build accurate and useful 3-D models of the interwell region; and design new ways to incorporate geological and geophysical information into reservoir simulation and verify the accuracy by comparison with production data. New analytical methods developed in the project are leading to a more realistic characterization of fractured reservoir rocks. Testing diagnostic and predictive approaches was an integral part of the research, and several tests were successfully completed.

Laubach, S.E.; Marrett, R.; Rossen, W.; Olson, J.; Lake, L.; Ortega, O.; Gu, Y.; Reed, R.

1999-01-01T23:59:59.000Z

22

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

23

Improving Geologic and Engineering Models of Midcontinent Fracture and Karst-Modified Reservoirs Using New 3-D Seismic Attributes  

SciTech Connect (OSTI)

Our project goal was to develop innovative seismic-based workflows for the incremental recovery of oil from karst-modified reservoirs within the onshore continental United States. Specific project objectives were: (1) to calibrate new multi-trace seismic attributes (volumetric curvature, in particular) for improved imaging of karst-modified reservoirs, (2) to develop attribute-based, cost-effective workflows to better characterize karst-modified carbonate reservoirs and fracture systems, and (3) to improve accuracy and predictiveness of resulting geomodels and reservoir simulations. In order to develop our workflows and validate our techniques, we conducted integrated studies of five karst-modified reservoirs in west Texas, Colorado, and Kansas. Our studies show that 3-D seismic volumetric curvature attributes have the ability to re-veal previously unknown features or provide enhanced visibility of karst and fracture features compared with other seismic analysis methods. Using these attributes, we recognize collapse features, solution-enlarged fractures, and geomorphologies that appear to be related to mature, cockpit landscapes. In four of our reservoir studies, volumetric curvature attributes appear to delineate reservoir compartment boundaries that impact production. The presence of these compartment boundaries was corroborated by reservoir simulations in two of the study areas. Based on our study results, we conclude that volumetric curvature attributes are valuable tools for mapping compartment boundaries in fracture- and karst-modified reservoirs, and we propose a best practices workflow for incorporating these attributes into reservoir characterization. When properly calibrated with geological and production data, these attributes can be used to predict the locations and sizes of undrained reservoir compartments. Technology transfer of our project work has been accomplished through presentations at professional society meetings, peer-reviewed publications, Kansas Geological Survey Open-file reports, Master's theses, and postings on the project website: http://www.kgs.ku.edu/SEISKARST.

Susan Nissen; Saibal Bhattacharya; W. Lynn Watney; John Doveton

2009-03-31T23:59:59.000Z

24

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

25

Use of additives to improve microstructures and fracture resistance of silicon nitride ceramics  

DOE Patents [OSTI]

A high-strength, fracture-resistant silicon nitride ceramic material that includes about 5 to about 75 wt-% of elongated reinforcing grains of beta-silicon nitride, about 20 to about 95 wt-% of fine grains of beta-silicon nitride, wherein the fine grains have a major axis of less than about 1 micron; and about 1 to about 15 wt-% of an amorphous intergranular phase comprising Si, N, O, a rare earth element and a secondary densification element. The elongated reinforcing grains have an aspect ratio of 2:1 or greater and a major axis measuring about 1 micron or greater. The elongated reinforcing grains are essentially isotropically oriented within the ceramic microstructure. The silicon nitride ceramic exhibits a room temperature flexure strength of 1,000 MPa or greater and a fracture toughness of 9 MPa-m.sup.(1/2) or greater. The silicon nitride ceramic exhibits a peak strength of 800 MPa or greater at 1200 degrees C. Also included are methods of making silicon nitride ceramic materials which exhibit the described high flexure strength and fracture-resistant values.

Becher, Paul F. (Oak Ridge, TN); Lin, Hua-Tay (Oak Ridge, TN)

2011-06-28T23:59:59.000Z

26

Using Biosurfactants Produced from Agriculture Process Waste Streams to Improve Oil Recovery in Fractured Carbonate Reservoirs  

SciTech Connect (OSTI)

This report describes the progress of our research during the first 30 months (10/01/2004 to 03/31/2007) of the original three-year project cycle. The project was terminated early due to DOE budget cuts. This was a joint project between the Tertiary Oil Recovery Project (TORP) at the University of Kansas and the Idaho National Laboratory (INL). The objective was to evaluate the use of low-cost biosurfactants produced from agriculture process waste streams to improve oil recovery in fractured carbonate reservoirs through wettability mediation. Biosurfactant for this project was produced using Bacillus subtilis 21332 and purified potato starch as the growth medium. The INL team produced the biosurfactant and characterized it as surfactin. INL supplied surfactin as required for the tests at KU as well as providing other microbiological services. Interfacial tension (IFT) between Soltrol 130 and both potential benchmark chemical surfactants and crude surfactin was measured over a range of concentrations. The performance of the crude surfactin preparation in reducing IFT was greater than any of the synthetic compounds throughout the concentration range studied but at low concentrations, sodium laureth sulfate (SLS) was closest to the surfactin, and was used as the benchmark in subsequent studies. Core characterization was carried out using both traditional flooding techniques to find porosity and permeability; and NMR/MRI to image cores and identify pore architecture and degree of heterogeneity. A cleaning regime was identified and developed to remove organic materials from cores and crushed carbonate rock. This allowed cores to be fully characterized and returned to a reproducible wettability state when coupled with a crude-oil aging regime. Rapid wettability assessments for crushed matrix material were developed, and used to inform slower Amott wettability tests. Initial static absorption experiments exposed limitations in the use of HPLC and TOC to determine surfactant concentrations. To reliably quantify both benchmark surfactants and surfactin, a surfactant ion-selective electrode was used as an indicator in the potentiometric titration of the anionic surfactants with Hyamine 1622. The wettability change mediated by dilute solutions of a commercial preparation of SLS (STEOL CS-330) and surfactin was assessed using two-phase separation, and water flotation techniques; and surfactant loss due to retention and adsorption on the rock was determined. Qualitative tests indicated that on a molar basis, surfactin is more effective than STEOL CS-330 in altering wettability of crushed Lansing-Kansas City carbonates from oil-wet to water-wet state. Adsorption isotherms of STEOL CS-330 and surfactin on crushed Lansing-Kansas City outcrop and reservoir material showed that surfactin has higher specific adsorption on these oomoldic carbonates. Amott wettability studies confirmed that cleaned cores are mixed-wet, and that the aging procedure renders them oil-wet. Tests of aged cores with no initial water saturation resulted in very little spontaneous oil production, suggesting that water-wet pathways into the matrix are required for wettability change to occur. Further investigation of spontaneous imbibition and forced imbibition of water and surfactant solutions into LKC cores under a variety of conditions--cleaned vs. crude oil-aged; oil saturated vs. initial water saturation; flooded with surfactant vs. not flooded--indicated that in water-wet or intermediate wet cores, sodium laureth sulfate is more effective at enhancing spontaneous imbibition through wettability change. However, in more oil-wet systems, surfactin at the same concentration performs significantly better.

Stephen Johnson; Mehdi Salehi; Karl Eisert; Sandra Fox

2009-01-07T23:59:59.000Z

27

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

SciTech Connect (OSTI)

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

Mukul M. Sharma

2005-03-01T23:59:59.000Z

28

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

SciTech Connect (OSTI)

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

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

1998-12-01T23:59:59.000Z

29

Interferometric hydrofracture microseism localization using neighboring fracture  

E-Print Network [OSTI]

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

Poliannikov, Oleg V.

2011-05-19T23:59:59.000Z

30

Interferometric hydrofracture microseism localization using neighboring fracture  

E-Print Network [OSTI]

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

Poliannikov, Oleg V.

31

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

32

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

33

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

SciTech Connect (OSTI)

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

Riha, B

2005-10-31T23:59:59.000Z

34

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

35

Optimization of fracture treatment designs  

E-Print Network [OSTI]

length and fracture conductivity, and well spacing to optimize methane recovery and project economics of coalbed methane reservoirs. Anderson and Philflps g examined several methods of optimizing proppant selection. Proppant selection is very important...

Rueda, Jose Ignacio

2012-06-07T23:59:59.000Z

36

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

37

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.

38

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

39

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.

40

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

Note: This page contains sample records for the topic "improves fracture length" 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

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

42

Fractional Diffusion Modeling of Electromagnetic Induction in Fractured Rocks  

E-Print Network [OSTI]

-2 km, a zone where pores and fractures over various length scales are highly complicated. Spatial confinement of fluid or electric charge transport by the fractal geometry gives rise to interesting dynamic processes within the pore space and fractures...

Ge, Jianchao

2014-08-11T23:59:59.000Z

43

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

44

Carbon nanotube and nanofiber reinforcement for improving the flexural strength and fracture toughness of portland cement paste  

E-Print Network [OSTI]

The focus of the proposed research will be on exploring the use of nanotechnology-based nano-filaments, such as carbon nanotubes (CNTs) and nanofibers (CNFs), as reinforcement in improving the mechanical properties of portland cement paste as a...

Tyson, Bryan Michael

2012-07-16T23:59:59.000Z

45

FRACTURING FLUID CHARACTERIZATION FACILITY  

SciTech Connect (OSTI)

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

Subhash Shah

2000-08-01T23:59:59.000Z

46

Hydraulic Fracturing (Vermont)  

Broader source: Energy.gov [DOE]

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

47

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

48

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

Broader source: Energy.gov [DOE]

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

49

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

50

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

51

Relative Permeability of Fractured Rock  

SciTech Connect (OSTI)

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

Mark D. Habana

2002-06-30T23:59:59.000Z

52

Modeling the Ductile Brittle Fracture Transition in Reactor Pressure Vessel Steels using a Cohesive Zone Model based approach  

SciTech Connect (OSTI)

Fracture properties of Reactor Pressure Vessel (RPV) steels show large variations with changes in temperature and irradiation levels. Brittle behavior is observed at lower temperatures and/or higher irradiation levels whereas ductile mode of failure is predominant at higher temperatures and/or lower irradiation levels. In addition to such temperature and radiation dependent fracture behavior, significant scatter in fracture toughness has also been observed. As a consequence of such variability in fracture behavior, accurate estimates of fracture properties of RPV steels are of utmost importance for safe and reliable operation of reactor pressure vessels. A cohesive zone based approach is being pursued in the present study where an attempt is made to obtain a unified law capturing both stable crack growth (ductile fracture) and unstable failure (cleavage fracture). The parameters of the constitutive model are dependent on both temperature and failure probability. The effect of irradiation has not been considered in the present study. The use of such a cohesive zone based approach would allow the modeling of explicit crack growth at both stable and unstable regimes of fracture. Also it would provide the possibility to incorporate more physical lower length scale models to predict DBT. Such a multi-scale approach would significantly improve the predictive capabilities of the model, which is still largely empirical.

Pritam Chakraborty; S. Bulent Biner

2013-10-01T23:59:59.000Z

53

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

54

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

55

Drainage fracture networks in elastic solids with internal fluid gen-Maya Kobchenko1  

E-Print Network [OSTI]

epl draft Drainage fracture networks in elastic solids with internal fluid gen- eration Maya layer to fracture. The gas produced is drained on short length scales by diffusion and on long length scales by flow in a fracture network, which has topological properties that are intermediate between

Galland, Olivier

56

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

E-Print Network [OSTI]

make necessary continuous efforts to reduce costs and improve efficiency in all aspects of drilling, completion and production techniques. Many of the recent improvements have been in well completions and hydraulic fracturing. Thus, the main goal of a...

Correa Castro, Juan

2011-08-08T23:59:59.000Z

57

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

58

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

59

An analysis of the connectivity of two-dimensional fracture patterns at Yucca Mountain, Nevada  

E-Print Network [OSTI]

for geometric analysis. Since connectivity is a complex function of fracture size and density, the orientation, length, trace center coordinates, and trace length censoring, as well as the number of intersections and their coordination numbers, were... of fractures to be modelled is conducive to extensive sampling, a deterministic approach can be utilized in which a numerical modeling method is used to simulate flow through individual fracture elements. More often, the number of fractures or the size...

Meinardus, Hans Wolfgang

1991-01-01T23:59:59.000Z

60

RESEARCH PROGRAM ON FRACTURED PETROLEUM RESERVOIRS  

SciTech Connect (OSTI)

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

Abbas Firoozabadi

2002-04-12T23:59:59.000Z

Note: This page contains sample records for the topic "improves fracture length" 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

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

62

Transient pressure behavior of multiple-fractured gas wells  

E-Print Network [OSTI]

with the dimensionless terms C = wk /vkxf and r xf 12 Xf 1/Xf2 where Cr is the dimensionless fracture conductivity and xf 1& is the fracture half-length ratio. fr 12 The symbols, xf1 and xf2, represent the half-length of the primary fracture and the auxiliary fr... actur e, respectively. Results also show that when C & 10, multiple fracture transient pressure behavior is significantly different from that of a single plane fr actur e. A family of type cur ves was constructed using cross-plots of Pwp vs tpx...

Choo, Yew Kai

1985-01-01T23:59:59.000Z

63

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

64

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

65

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

66

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

67

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

68

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 documented in literature on the subject. The ...

Arop, Julius Bankong

2013-01-01T23:59:59.000Z

69

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

70

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

71

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

SciTech Connect (OSTI)

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

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

1998-09-01T23:59:59.000Z

72

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

SciTech Connect (OSTI)

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

Huang, Hai; Plummer, Mitchell; Podgorney, Robert

2013-02-01T23:59:59.000Z

73

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

74

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

75

A Thermoelastic Hydraulic Fracture Design Tool for Geothermal Reservoir Development  

SciTech Connect (OSTI)

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

Ahmad Ghassemi

2003-06-30T23:59:59.000Z

76

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

77

The Fracture Toughness of Medium Density Fiberboard (MDF) Including the Effects of Fiber Bridging and Crack-Plane Interference  

E-Print Network [OSTI]

1 The Fracture Toughness of Medium Density Fiberboard (MDF) Including the Effects of Fiber Bridging University, Corvallis, OR, USA Abstract The fracture toughness of medium density fiberboard (MDF) as a function of crack length (R curve) was measured. Fracture toughness was determined from force

Nairn, John A.

78

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

79

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

80

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

Note: This page contains sample records for the topic "improves fracture length" 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

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

82

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

83

Editorial: Redefining Length  

SciTech Connect (OSTI)

Technological changes have moved publishing to electronic-first publication where the print version has been relegated to simply another display mode. Distribution in HTML and EPUB formats, for example, changes the reading environment and reduces the need for strict pagination. Therefore, in an effort to streamline the calculation of length, the APS journals will no longer use the printed page as the determining factor for length. Instead the journals will now use word counts (or word equivalents for tables, figures, and equations) to establish length; for details please see http://publish.aps.org/authors/length-guide. The title, byline, abstract, acknowledgment, and references will not be included in these counts allowing authors the freedom to appropriately credit coworkers, funding sources, and the previous literature, bringing all relevant references to the attention of readers. This new method for determining length will be easier for authors to calculate in advance, and lead to fewer length-associated revisions in proof, yet still retain the quality of concise communication that is a virtue of short papers.

Sprouse, Gene D. [American Physical Society (United States)

2011-07-15T23:59:59.000Z

84

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

85

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

86

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

87

Statistical analysis of surface lineaments and fractures for characterizing naturally fractured reservoirs  

SciTech Connect (OSTI)

Thirty-six sets of surface lineaments and fractures mapped from satellite images and/or aerial photos from parts of the Mid-continent and Colorado Plateau regions were collected, digitized, and statistically analyzed in order to obtain the probability distribution functions of natural fractures for characterizing naturally fractured reservoirs. The orientations and lengths of the surface linear features were calculated using the digitized coordinates of the two end points of each individual linear feature. The spacing data of the surface linear features within an individual set were, obtained using a new analytical sampling technique. Statistical analyses were then performed to find the best-fit probability distribution functions for the orientation, length, and spacing of each data set. Twenty-five hypothesized probability distribution functions were used to fit each data set. A chi-square goodness-of-fit test was used to rank the significance of each fit. A distribution which provides the lowest chi-square goodness-of-fit value was considered the best-fit distribution. The orientations of surface linear features were best-fitted by triangular, normal, or logistic distributions; the lengths were best-fitted by PearsonVI, PearsonV, lognormal2, or extreme-value distributions; and the spacing data were best-fitted by lognormal2, PearsonVI, or lognormal distributions. These probability functions can be used to stochastically characterize naturally fractured reservoirs.

Guo, Genliang; George, S.A.; Lindsey, R.P.

1997-08-01T23:59:59.000Z

88

Factors that affect fracture fluid clean-up and pressure buildup test results in tight gas reservoirs  

E-Print Network [OSTI]

engineering effort with a complete formation evaluation prior to the stimulation treatment can one understand a well containing a vertical hydraulic fracture. If the reservoir produces substantial volumes of either fracture fluid or formation water, along... and Water Permeability . . . 21 Fracture Relative Gas and Water Permeability . . . . . . 24 Created and Propped Fracture Lengths as a Function of Treatment Volume Based on FRACDIM ZI One Quarter of a Square Pattern with Wellbore Centered in Middle...

Montgomery, Kevin Todd

1990-01-01T23:59:59.000Z

89

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...

90

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

91

Method and apparatus for determining two-phase flow in rock fracture  

DOE Patents [OSTI]

An improved method and apparatus as disclosed for measuring the permeability of multiple phases through a rock fracture. The improvement in the method comprises delivering the respective phases through manifolds to uniformly deliver and collect the respective phases to and from opposite edges of the rock fracture in a distributed manner across the edge of the fracture. The improved apparatus comprises first and second manifolds comprising bores extending within porous blocks parallel to the rock fracture for distributing and collecting the wetting phase to and from surfaces of the porous blocks, which respectively face the opposite edges of the rock fracture. The improved apparatus further comprises other manifolds in the form of plenums located adjacent the respective porous blocks for uniform delivery of the non-wetting phase to parallel grooves disposed on the respective surfaces of the porous blocks facing the opposite edges of the rock fracture and generally perpendicular to the rock fracture.

Persoff, Peter (Oakland, CA); Pruess, Karsten (Berkeley, CA); Myer, Larry (Benicia, CA)

1994-01-01T23:59:59.000Z

92

Evaluation of fracture treatments using a layered-reservoir description: Field examples  

SciTech Connect (OSTI)

This paper presents a practical analysis technique to determine actual fracture geometry and proppant profile using a three-dimensional (3D) hydraulic-fracturing simulator. The hydraulic-fracturing model used in this study considers the variation of in-situ stress, Young`s modulus, Poisson`s ratio, and net pay thickness in the productive interval. When the method is applied, the results from the fracture propagation model conform well with the results the authors obtain from pressure-buildup and production-data analyses. This study analyzed hydraulic-fracturing treatments from several wells in the Vicksburg formation of the McAllen Ranch area in south Texas. The authors have provided guidelines to properly describe the treatment interval, how to use this information in the analysis of such fracture treatments, and how to confirm the results using pressure-transient tests and production-data analyses. This paper presents examples illustrating that a detailed description of the reservoir layers is essential to properly evaluate hydraulic-fracture treatments. For the example wells presented in this paper, post-fracture-production and pressure-transient data were available. The authors have analyzed production and pressure-transient data to estimate permeability and fracture half-length. The values of fracture half-length used to analyze the production data matched closely with those predicted by the fracture model.

Rahim, Z.; Holditch, S.A.; Zuber, M.D. [Holditch and Associates Inc., College Station, TX (United States); Buehring, D.R.

1998-02-01T23:59:59.000Z

93

EVALUATION OF PERFORMANCE OF CYCLIC STEAM INJECTION IN NATURALLY FRACTURED RESERVOIRS – AN ARTIFICIAL NEURAL NETWORK APPLICATION.  

E-Print Network [OSTI]

??With increasing demand on oil, it is important to improve the recovery factor of oil reservoirs. Naturally fractured reservoirs constitute a major portion of world’s… (more)

Chintalapati, Santosh Phani Bhushan

2011-01-01T23:59:59.000Z

94

Planck-Length Phenomenology  

E-Print Network [OSTI]

This author's recent proposal of interferometric tests of Planck-scale-related properties of space-time is here revisited from a strictly phenomenological viewpoint. The results announced previously are rederived using elementary dimensional considerations. The dimensional analysis is then extended to the other two classes of experiments (observations of neutral kaons at particle accelerators and observations of the gamma rays we detect from distant astrophysical sources) which have been recently considered as opportunities to explore "foamy" properties of space-time. The emerging picture suggests that there is an objective and intuitive way to connect the sensitivities of these three experiments with the Planck length. While in previous studies the emphasis was always on some quantum-gravity scenario and the analysis was always primarily aimed at showing that the chosen scenario would leave a trace in a certain class of doable experiments, the analysis here reported takes as starting point the experiments and, by relating in a direct quantitative way the sensitivities to the Planck length, provides a model-independent description of the status of Planck-length phenomenology.

Giovanni Amelino-Camelia

2000-08-04T23:59:59.000Z

95

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

96

Fracture mechanics evaluation for at typical PWR primary coolant pipe  

SciTech Connect (OSTI)

For the primary coolant piping of PWRs in Japan, cast duplex stainless steel which is excellent in terms of strength, corrosion resistance, and weldability has conventionally been used. The cast duplex stainless steel contains the ferrite phase in the austenite matrix and thermal aging after long term service is known to change its material characteristics. It is considered appropriate to apply the methodology of elastic plastic fracture mechanics for an evaluation of the integrity of the primary coolant piping after thermal aging. Therefore we evaluated the integrity of the primary coolant piping for an initial PWR plant in Japan by means of elastic plastic fracture mechanics. The evaluation results show that the crack will not grow into an unstable fracture and the integrity of the piping will be secured, even when such through wall crack length is assumed to equal the fatigue crack growth length for a service period of up to 60 years.

Tanaka, T. [Kansai Electric Power Company, Osaka (Japan); Shimizu, S.; Ogata, Y. [Mitsubishi Heavy Industries, Ltd., Kobe (Japan)

1997-04-01T23:59:59.000Z

97

Fractal model for estimating fracture toughness of carbon nanotube reinforced aluminum oxide  

SciTech Connect (OSTI)

The current work focuses on predicting the fracture toughness of Al{sub 2}O{sub 3} ceramic matrix composites using a modified Mandelbrot's fractal approach. The first step confirms that the experimental fracture toughness values fluctuate within the fracture toughness range predicted as per the modified fractal approach. Additionally, the secondary reinforcements [such as carbon nanotubes (CNTs)] have shown to enhance the fracture toughness of Al{sub 2}O{sub 3}. Conventional fractural toughness evaluation via fractal approach underestimates the fracture toughness by considering the shortest crack path. Hence, the modified Mandelbrot's fractal approach considers the crack propagation along the CNT semicircumferential surface (three-dimensional crack path propagation) for achieving an improved fracture toughness estimation of Al{sub 2}O{sub 3}-CNT composite. The estimations obtained in the current approach range within 4% error regime of the experimentally measured fracture toughness values of the Al{sub 2}O{sub 3}-CNT composite.

Rishabh, Abhishek; Joshi, Milind R.; Balani, Kantesh [Department of Materials and Metallurgical Engineering, Indian Institute of Technology Kanpur, Kanpur 208016 (India)

2010-06-15T23:59:59.000Z

98

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

99

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

100

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

Note: This page contains sample records for the topic "improves fracture length" 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

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

102

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

103

Energy-Length Rule  

E-Print Network [OSTI]

Lorentz ordering (causality) implies the following rule: for any given energy p0 of a system there is a certain interval c0 on x0 so that their product is the Lorentz ordering constant L It means p0c0 = L. The constant L=hc. Hence Planck constant h in a similar way as c are both consequences of Lorentz metric. The basic ideas are: 1. Lorentz metric implies that x0 must represent a length like the other components of x in X 2. The dual metric space X* is well defined since the Lorentz metric tensor is not singular. The components of the vectors p in X*are interpreted as representing energy. The properties of the physical systems that are direct consequences of the detailed structure of X and X*, and so expressed through the Lorentz Limit L are presented.

Alexandru C Mihul; Eleonora A Mihul

2006-08-25T23:59:59.000Z

104

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

105

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

106

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

SciTech Connect (OSTI)

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

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

1995-12-31T23:59:59.000Z

107

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

108

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

109

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

110

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...

111

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...

112

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

113

Experimental and Analytical Study of Multidimensional Imbibition in Fractured Porous Media, SUPRI TR-129  

SciTech Connect (OSTI)

Using an X-ray computerized tomography (CT) scanner, and a novel, CT-compatible core holder, performed a series of experiments to study air and oil expulsion from rock samples by capillary imbibition of water in a three-dimensional geometry. The air-water system was useful in that a relatively large number of experiments can be conducted to delineate physical processes. Different injection rates and fracture apertures were utilized. Two different fracture flow regimes were identified. The ''filling-fracture'' regime shows a plane source that grows in length due to relatively slow water flow through fractures. In the second, ''instantly-filled fracture'' regime, the time to fill the fracture is much less than the imbibition time. Here, imbibition performance scales as the square root of time. In the former regime, the mass of water imbibed scales linearly with time.

Rangel-German, E.R.; Kovscek, A.R.

2002-04-24T23:59:59.000Z

114

CONFORMANCE IMPROVEMENT USING GELS  

SciTech Connect (OSTI)

This report describes work performed during the third and final year of the project, ''Conformance Improvement Using Gels.'' Corefloods revealed throughput dependencies of permeability reduction by polymers and gels that were much more prolonged during oil flow than water flow. This behavior was explained using simple mobility ratio arguments. A model was developed that quantitatively fits the results and predicts ''clean up'' times for oil productivity when production wells are returned to service after application of a polymer or gel treatment. X-ray computed microtomography studies of gels in strongly water-wet Berea sandstone and strongly oil-wet porous polyethylene suggested that oil penetration through gel-filled pores occurs by a gel-dehydration mechanism, rather than gel-ripping or gel-displacement mechanisms. In contrast, analysis of data from the University of Kansas suggests that the gel-ripping or displacement mechanisms are more important in more permeable, strongly water-wet sandpacks. These findings help to explain why aqueous gels can reduce permeability to water more than to oil under different conditions. Since cement is the most commonly used material for water shutoff, we considered when gels are preferred over cements. Our analysis and experimental results indicated that cement cannot be expected to completely fill (top to bottom) a vertical fracture of any width, except near the wellbore. For vertical fractures with apertures less than 4 mm, the cement slurry will simply not penetrate very far into the fracture. For vertical fractures with apertures greater than 4 mm, the slurry may penetrate a substantial distance into the bottom part of the fracture. However, except near the wellbore, the upper part of the fracture will remain open due to gravity segregation. We compared various approaches to plugging fractures using gels, including (1) varying polymer content, (2) varying placement (extrusion) rate, (3) using partially formed gels, (4) using combinations of high and low molecular weight (Mw) polymers, (5) using secondary crosslinking reactions, (6) injecting un-hydrated polymer particles, and (7) incorporating particulates. All of these methods showed promise in some aspects, but required performance improvements in other aspects. All materials investigated to date showed significant performance variations with fracture width. High pressure gradients and limited distance of penetration are common problems in tight fractures. Gravity segregation and low resistance to breaching are common problems in wide fractures. These will be key issues to address in future work. Although gels can exhibit disproportionate permeability reduction in fractures, the levels of permeability reduction for oil flow are too high to allow practical exploitation in most circumstances. In contrast, disproportionate permeability reduction provided by gels that form in porous rock (adjacent to the fractures) has considerable potential in fractured systems.

Randall S. Seright

2004-09-30T23:59:59.000Z

115

Simulation studies to evaluate the effect of fracture closure on the performance of naturally fractured reservoirs. Annual report  

SciTech Connect (OSTI)

The first of a three-year research program to evaluate the effect of fracture closure on the recovery of oil and gas from naturally fractured reservoirs has been completed. The objectives of the study are to (1) evaluate the reservoir conditions where fracture closure is significant, and (2) evaluate innovative fluid injection techniques capable of maintaining pressure within the reservoir. Simulation studies were conducted with a dual porosity simulator capable of simulating the performance of vertical and horizontal wells. Each simulator was initialized using properties typical of the Austin Chalk reservoir in Pearsall Field, Texas. Simulations of both vertical and horizontal well performance were made assuming that fracture permeability was insensitive to pressure change. Sensitivity runs indicate that the simulator is predicting the effects of critical reservoir parameters in a logical and consistent manner. The results to-date confirm that horizontal wells can increase both oil recovery rate and total oil recovery from naturally fractured reservoirs. The year one simulation results will provide the baseline for the ongoing study which will evaluate the performance degradation caused by the sensitivity of fracture permeability to pressure change, and investigate fluid injection pressure maintenance as a means to improve oil recovery performance. The study is likely to conclude that fracture closure decreases oil recovery and that pressure support achieved through fluid injection could be beneficial in improving recovery.

Not Available

1991-10-01T23:59:59.000Z

116

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

117

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

118

A comparison of microseismicity induced by gel-proppant-and water-injected hydraulic fractures, Carthage Cotton Valley gas field, East Texas  

E-Print Network [OSTI]

results in self-propping (shear dilation enhanced by fracture branching, proppant and spalled rock. With improved source location precision and focal mechanism determination (fracture plane orientation and sense

119

New hydrocracking catalysts increase throughput, run length  

SciTech Connect (OSTI)

An improved, second-stage hydrocracking catalyst has been developed by combining stabilized Y zeolites with amorphous silica alumina cracking components. A commercial application of this catalyst, along with a new, first-stage zeolitic hydrocracking catalyst, resulted in increased unit throughput and cycle length. The paper discusses the hydrocracking process, first-stage catalysts, second-stage catalysts, hydrogenation process, commercial results, and product properties.

Huizinga, T. [Shell Internationale Petroleum Mij., The Hague (Netherlands); Theunissen, J.M.H. [Rayong Refinery Co. Ltd., Rayong (Thailand); Minderhoud, H.; Veen, R. van [Koninklijke/Shell-Lab., Amsterdam (Netherlands)

1995-06-26T23:59:59.000Z

120

CHARACTERIZATION OF IN-SITU STRESS AND PERMEABILITY IN FRACTURED RESERVOIRS  

SciTech Connect (OSTI)

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

Daniel R. Burns; M. Nafi Toksoz

2004-07-19T23:59:59.000Z

Note: This page contains sample records for the topic "improves fracture length" 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

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

122

Failure of a gas well to respond to a foam hydraulic fracturing treatment  

SciTech Connect (OSTI)

Well No. 1 (not the real name of the well) is not producing gas at maximum capacity following a foam hydraulic fracturing treatment performed upon completion of the well in 1987. The failure of the stimulation treatment, which has affected other wells throughout the field, was due to a combination of three factors: (1) downward fracture growth and proppant settling during injection (2) embedment due to a high pressure drawdown in the wellbore during flowback procedures, and (3) poor cleanup of the fracture fluid due to high capillary pressures. The following are recommendations to help improve future fracturing treatments throughout the field: (1) Fracture at lower treating pressures; (2) Improve perforating techniques; (3) Change flowback procedures; and (4) Evaluate using N{sub 2} as a fracture fluid.

Rauscher, B.D.

1996-12-31T23:59:59.000Z

123

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...

124

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...

125

Identification and quantification of fracture behavior through reservoir simulation  

SciTech Connect (OSTI)

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

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

1995-08-01T23:59:59.000Z

126

High Energy Gas Fracturing Test  

SciTech Connect (OSTI)

The Rocky Mountain Oilfield Testing Center (RMOTC) has recently completed two tests of a high-energy gas fracturing system being developed by Western Technologies of Crossville, Tennessee. The tests involved the use of two active wells located at the Naval Petroleum Reserve No. 3 (NPR-3), thirty-five miles north of Casper, Wyoming (See Figure 1). During the testing process the delivery and operational system was enhanced by RMOTC, Western Technologies, and commercial wireline subcontractors. RMOTC has assisted an industrial client in developing their technology for high energy gas fracturing to a commercial level. The modifications and improvements implemented during the technology testing process are instrumental in all field testing efforts at RMOTC. The importance of well selection can also be critical in demonstrating the success of the technology. To date, significant increases in well productivity have been clearly proven in well 63-TPX-10. Gross fluid production was initially raised by a factor of three. Final production rates increased by a factor of six with the use of a larger submersible pump. Well productivity (bbls of fluid per foot of drawdown) increased by a factor of 15 to 20. The above results assume that no mechanical damage has occurred to the casing or cast iron bridge plug which could allow well production from the Tensleep ''B'' sand. In the case of well 61-A-3, a six-fold increase in total fluid production was seen. Unfortunately, the increase is clouded by the water injection into the well that was necessary to have a positive fluid head on the propellant tool. No significant increase in oil production was seen. The tools which were retrieved from both 63-TPX-10 and 61-A-3 indicated a large amount of energy, similar to high gram perforating, had been expended downhole upon the formation face.

Schulte, R.

2001-02-27T23:59:59.000Z

127

Fracture Toughness and Maximum Stress in a Disordered Lattice System  

E-Print Network [OSTI]

Fracture in a disordered lattice system is studied. In our system, particles are initially arranged on the triangular lattice and each nearest-neighbor pair is connected with a randomly chosen soft or hard Hookean spring. Every spring has the common threshold of stress at which it is cut. We make an initial crack and expand the system perpendicularly to the crack. We find that the maximum stress in the stress-strain curve is larger than those in the systems with soft or hard springs only (uniform systems). Energy required to advance fracture is also larger in some disordered systems, which indicates that the fracture toughness improves. The increase of the energy is caused by the following two factors. One is that the soft spring is able to hold larger energy than the hard one. The other is that the number of cut springs increases as the fracture surface becomes tortuous in disordered systems.

Chiyori Urabe; Shinji Takesue

2008-12-29T23:59:59.000Z

128

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

129

Integrated 3D Acid Fracturing Model for Carbonate Reservoir Stimulation  

E-Print Network [OSTI]

along fracture length ?Dz Normalized correlation length along fracture height ?c Closure stress, psi ?D Normalized standard deviation vii TABLE OF CONTENTS Page ABSTRACT... 0.117 0.116 0.114 0.113 0.112 0.11 0.109 0.107 0.105 0.103 0.101 0.099 0.010 0.205 0.204 0.202 0.2 0.198 0.196 0.193 0.19 0.186 0.183 0.179 0.176 0.042 0.234 0.232 0.23 0.228 0.226 0.223 0.22 0.216 0.212 0.207 0.203 0.198 0.193 0...

Wu, Xi

2014-06-23T23:59:59.000Z

130

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

131

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

132

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

133

Observations of long period earthquakes accompanying hydraulic fracturing  

SciTech Connect (OSTI)

Waveforms of most seismic events accompanying hydraulic fracturing have been reported to contain clear P and S waves and have fault plane solutions consistent with shear displacement across a fault. This observation is surprising since classical hydraulic fracturing theory predicts the creation of a tensile opening of a cavity in response to fluid pressure. Very small long period events, similar to long period earthquakes observed at volcanoes, were found to occur during four hydraulic fracturing experiments carried out at Fenton Hill, New Mexico. Since the long period earthquakes occur in the same region as the shear type events, it is concluded that the unusual character of the long period earthquake waveforms is due to a source effect and not a path effect. The occurrence of long period earthquakes during hydraulic fracturing could indicate tensile fracturing. Many waveforms of these events are identical, which implies that these events represent repeated activation of a given source. A proposed source for these long period events is the sudden opening of a channel that connects two cracks filled with fluid at different pressures. The sizes of the two cracks differ, which causes two or more peaks to appear in the spectra, each peak being associated with one physical dimension of each crack. From the frequencies at which spectral peaks occur, crack lengths are estimated to be between 3 and 20m.

Bame, D.; Fehler, M.

1986-02-01T23:59:59.000Z

134

CONFORMANCE IMPROVEMENT USING GELS  

SciTech Connect (OSTI)

This report describes work performed during the second year of the project, ''Conformance Improvement Using Gels.'' The project has two objectives. The first objective is to identify gel compositions and conditions that substantially reduce flow through fractures that allow direct channeling between wells, while leaving secondary fractures open so that high fluid injection and production rates can be maintained. The second objective is to optimize treatments in fractured production wells, where the gel must reduce permeability to water much more than that to oil. Pore-level images from X-ray computed microtomography were re-examined for Berea sandstone and porous polyethylene. This analysis suggests that oil penetration through gel-filled pores occurs by a gel-dehydration mechanism, rather than a gel-ripping mechanism. This finding helps to explain why aqueous gels can reduce permeability to water more than to oil. We analyzed a Cr(III)-acetate-HPAM gel treatment in a production well in the Arbuckle formation. The availability of accurate pressure data before, during, and after the treatment was critical for the analysis. After the gel treatment, water productivity was fairly constant at about 20% of the pre-treatment value. However, oil productivity was stimulated by a factor of 18 immediately after the treatment. During the six months after the treatment, oil productivity gradually decreased to approach the pre-treatment value. To explain this behavior, we proposed that the fracture area open to oil flow was increased substantially by the gel treatment, followed by a gradual closing of the fractures during subsequent production. For a conventional Cr(III)-acetate-HPAM gel, the delay between gelant preparation and injection into a fracture impacts the placement, leakoff, and permeability reduction behavior. Formulations placed as partially formed gels showed relatively low pressure gradients during placement, and yet substantially reduced the flow capacity of fractures (with widths from 1 to 4 mm) during brine and oil flow after placement. Regardless of gel age before placement, very little gel washed out from the fractures during brine or oil flow. However, increased brine or oil flow rate and cyclic injection of oil and water significantly decreased the level of permeability reduction. A particular need exists for gels that can plug large apertures (e.g., wide fractures and vugs). Improved mechanical strength and stability were demonstrated (in 1- to 4-mm-wide fractures) for a gel that contained a combination of high- and low-molecular weight polymers. This gel reduced the flow capacity of 2- and 4-mm-wide fractures by 260,000. In a 1-mm-wide fracture, it withstood 26 psi/ft without allowing any brine flow through the fracture. Cr(III)-acetate-HPAM gels exhibited disproportionate permeability reduction in fractures. The effect was most pronounced when the gel was placed as gelant or partially formed gels. The effect occurred to a modest extent with concentrated gels and with gels that were ''fully formed'' when placed. The effect was not evident in tubes. We explored swelling polymers for plugging fractures. Polymer suspensions were quickly prepared and injected. In concept, the partially dissolved polymer would lodge and swell to plug the fracture. For three types of swelling polymers, behavior was promising. However, additional development is needed before their performance will be superior to that of conventional gels.

Randall S. Seright

2003-09-01T23:59:59.000Z

135

Coordinated studies in support of hydraulic fracturing of coalbed methane. Final report, July 1990-May 1995  

SciTech Connect (OSTI)

The primary objective of this project is to provide laboratory data that is pertinent to designing hydraulic fracturing treatments for coalbed methane. Coal fluid interactions studies, fracture conductivity, fluid leak-off through cleats, rheology, and proppant transport are designed to respresent Black Warrior and San Juan treatments. A second objective is to apply the information learned in laboratory testing to actual hydraulic fracturing treatments in order to improve results. A final objective is to review methods currently used to catalog well performance following hydraulic fracturing for the purpose of placing the data in a useable database that can be accessed by users to determine the success of various treatment scenarios.

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

1996-02-01T23:59:59.000Z

136

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

137

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

138

The evolution of an applied hydraulic fracture project, Frontier Formation Moxa Arch, Wyoming  

SciTech Connect (OSTI)

This paper demonstrates a methodical approach in the implementation of current hydraulic fracturing technologies. Specific examples illustrating the evolution of a consistent reservoir/hydraulic fracturing interpretation are presented in a case history of three GRI-Industry Technology Transfer wells. Detailed modeling of these project wells provided an overall reservoir and hydraulic fracture description that was consistent with respect to all observations. Based on identification of the fracturing mechanisms occurring, the second and third project wells show the capabilities of real-time diagnostics in the implementation of hydraulic fracture treatments. By optimizing the pad volume and fluid integrity to avoid premature screenouts, significant cost savings and improved proppant placement were achieved. The production and pressure build-up response in the first project well verifies the overall interpretation of the reservoir/hydraulic fracture model and provides the basis for eliminating the use of moderate strength/higher cost proppant over sand in low permeability/higher closure stress environments.

Harkrider, J.D.; Aud, W.W.; Cipolla, C.L.; Hansen, J.T.

1994-12-31T23:59:59.000Z

139

Exploring the physicochemical processes that govern hydraulic fracture through laboratory  

E-Print Network [OSTI]

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

Belmonte A; Connelly P

140

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...

Note: This page contains sample records for the topic "improves fracture length" 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

Seismic monitoring of the growth of a hydraulic fracture zone at Fenton Hill, New Mexico  

SciTech Connect (OSTI)

The hydraulic fracturing technique is an important method for enhancing hydrocarbon recovery, geothermal energy extraction, and solid waste disposal. Determination of the geometry and growth process of a hydraulic fracture zone is important for monitoring and assessing subsurface fractures. A relative-source-location approach, based on a waveform correlation and a grid search method, has been developed to estimate relative hypocenter locations for a cluster of 157 microearthquakes induced by hydraulic fracturing at the Los Alamos Hot Dry Rock (HDR) geothermal site. Among the 157 events, 147 microearthquakes occurred in a tight cluster with a dimension of 40 m, roughly defining a vertical hydraulic fracture zone with an orientation of N40{degree}W. The length, height, and width of the hydraulic fracture zone are estimated to be 40, 35, and 5 m, respectively. Analysis of the spatial-temporal pattern of the induced microearthquakes reveals that the fracture zone grew significantly, averaging 0.2m/ minute in a two-hour period toward the northwest along the fracture zone strike.

Li, Y.; Cheng, C.H.; Toksoez, M.N. [Massachusetts Inst. of Tech., Cambridge, MA (United States)] [Massachusetts Inst. of Tech., Cambridge, MA (United States)

1998-01-01T23:59:59.000Z

142

Upscaling solute transport in naturally fractured porous media with the continuous time random walk method  

SciTech Connect (OSTI)

Solute transport in fractured porous media is typically 'non-Fickian'; that is, it is characterized by early breakthrough and long tailing and by nonlinear growth of the Green function-centered second moment. This behavior is due to the effects of (1) multirate diffusion occurring between the highly permeable fracture network and the low-permeability rock matrix, (2) a wide range of advection rates in the fractures and, possibly, the matrix as well, and (3) a range of path lengths. As a consequence, prediction of solute transport processes at the macroscale represents a formidable challenge. Classical dual-porosity (or mobile-immobile) approaches in conjunction with an advection-dispersion equation and macroscopic dispersivity commonly fail to predict breakthrough of fractured porous media accurately. It was recently demonstrated that the continuous time random walk (CTRW) method can be used as a generalized upscaling approach. Here we extend this work and use results from high-resolution finite element-finite volume-based simulations of solute transport in an outcrop analogue of a naturally fractured reservoir to calibrate the CTRW method by extracting a distribution of retention times. This procedure allows us to predict breakthrough at other model locations accurately and to gain significant insight into the nature of the fracture-matrix interaction in naturally fractured porous reservoirs with geologically realistic fracture geometries.

Geiger, S.; Cortis, A.; Birkholzer, J.T.

2010-04-01T23:59:59.000Z

143

Nanotube fracture during the failure of carbon nanotube/ alumina composites  

E-Print Network [OSTI]

-based ceramic composites, leading to improved fracture toughness. � 2011 Elsevier Ltd. All rights reserved. 1 problem, incorporation of particulates, flakes and short/long fibers into ceramics matrix, as a second, chemical and electrical properties [3­7], motivating their use in ceramic composite materials as a fibrous

144

Percutaneous Stabilization of Impending Pathological Fracture of the Proximal Femur  

SciTech Connect (OSTI)

Objective: Percutaneous osteosynthesis plus cementoplasty (POPC) is a minimally invasive technique that has never been reported before and that we have prospectively evaluated for patients with impending pathological fracture of the proximal femur. Methods: We performed POPC in 12 patients (3 males, 9 females) with metastasis of the proximal femur with a high risk of fracture (Mirels' score {>=}8) between February 2010 and July 2011. Patients were not candidates for standard surgical stabilization. We analyzed the feasibility, duration, and complication of the procedure, the risk of fracture, the decrease in pain (Visual Analog Scale, VAS), and length of stay in hospital. Data were prospectively collected in all patients. Results: The mean Mirels' score was 9.8 {+-} 1.2 (range, 8-11). The technical success was 100%. POPC was performed under general anesthesia (n = 6) or conscious sedation (n = 6). The mean duration was 110 {+-} 43 (range, 60-180) minutes. All patients stood up and walked the second day after the procedure. The average length of stay in the hospital was 4 {+-} 1.6 (range, 2-7) days. We experienced two hematomas in two patients and no thromboembolic complication. For symptomatic patients (n = 8), VAS decreased from 6.5/10 (range, 2-9) before treatment to 1/10 (range, 0-3) 1 month after. No fracture occurred after a median follow-up of 145 (range, 12-608) days. Conclusions: POPC for impending pathological fracture of the proximal femur seems to be a promising alternative for cancer patients who are not candidates for surgical stabilization. Further studies are required to confirm this preliminary experience.

Deschamps, Frederic, E-mail: frederic.deschamps@igr.fr; Farouil, Geoffroy, E-mail: g.farouil@gmail.com; Hakime, Antoine, E-mail: thakime@yahoo.com; Teriitehau, Christophe, E-mail: cteriitehau@me.com; Barah, Ali, E-mail: ali.barah@gmail.com; Baere, Thierry de, E-mail: debaere@igr.fr [Institut Gustave Roussy, Interventional Radiology Department (France)

2012-12-15T23:59:59.000Z

145

Continuously variable focal length lens  

DOE Patents [OSTI]

A material preferably in crystal form having a low atomic number such as beryllium (Z=4) provides for the focusing of x-rays in a continuously variable manner. The material is provided with plural spaced curvilinear, optically matched slots and/or recesses through which an x-ray beam is directed. The focal length of the material may be decreased or increased by increasing or decreasing, respectively, the number of slots (or recesses) through which the x-ray beam is directed, while fine tuning of the focal length is accomplished by rotation of the material so as to change the path length of the x-ray beam through the aligned cylindrical slows. X-ray analysis of a fixed point in a solid material may be performed by scanning the energy of the x-ray beam while rotating the material to maintain the beam's focal point at a fixed point in the specimen undergoing analysis.

Adams, Bernhard W; Chollet, Matthieu C

2013-12-17T23:59:59.000Z

146

Fracturing Fluid Cleanup by Controlled Release of Enzymes from Polyelectrolyte Complex Nanoparticles  

E-Print Network [OSTI]

Guar-based polymer gels are used in the oil and gas industry to viscosify fluids used in hydraulic fracturing of production wells, in order to reduce leak-off of fluids and pressure, and improve the transport of proppants. ...

Barati Ghahfarokhi, Reza

2010-12-10T23:59:59.000Z

147

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

Broader source: Energy.gov [DOE]

Project objectives: Improve image resolution for microseismicimaging and time-lapse active seismic imaging; Enhance the prediction of fluid flow and temperature distributions and stress changes by coupling fracture flow simulations with reservoir flow simulations; and integrating imaging into modeling.

148

Effect of nano-scale twinning on the fracture, fatigue and wear properties of copper  

E-Print Network [OSTI]

Grain refinement in materials has been one of the most common strategies for improving the strength of materials. However this comes at the price of reduced ductility, fracture toughness and stable fatigue crack propagation ...

Singh, Aparna, Ph.D. Massachusetts Institute of Technology

2011-01-01T23:59:59.000Z

149

Continuous lengths of oxide superconductors  

DOE Patents [OSTI]

A layered oxide superconductor prepared by depositing a superconductor precursor powder on a continuous length of a first substrate ribbon. A continuous length of a second substrate ribbon is overlaid on the first substrate ribbon. Sufficient pressure is applied to form a bound layered superconductor precursor powder between the first substrate ribbon and the second substrate ribbon. The layered superconductor precursor is then heat treated to establish the oxide superconducting phase. The layered oxide superconductor has a smooth interface between the substrate and the oxide superconductor.

Kroeger, Donald M. (Knoxville, TN); List, III, Frederick A. (Andersonville, TN)

2000-01-01T23:59:59.000Z

150

Exploiting Universality in Atoms with Large Scattering Lengths  

SciTech Connect (OSTI)

The focus of this research project was atoms with scattering lengths that are large compared to the range of their interactions and which therefore exhibit universal behavior at sufficiently low energies. Recent dramatic advances in cooling atoms and in manipulating their scattering lengths have made this phenomenon of practical importance for controlling ultracold atoms and molecules. This research project was aimed at developing a systematically improvable method for calculating few-body observables for atoms with large scattering lengths starting from the universal results as a first approximation. Significant progress towards this goal was made during the five years of the project.

Braaten, Eric

2012-05-31T23:59:59.000Z

151

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

152

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.

153

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

154

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.

155

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

SciTech Connect (OSTI)

The flow parameters of a natural fracture were estimated by modeling in situ pressure pulses. The pulses were generated in two horizontal boreholes spaced 1 m apart vertically and intersecting a near-vertical highly permeable fracture located within a shallow fractured carbonate reservoir. Fracture hydromechanical response was monitored using specialized fiber-optic borehole equipment that could simultaneously measure fluid pressure and fracture displacements. Measurements indicated a significant time lag between the pressure peak at the injection point and the one at the second measuring point, located 1 m away. The pressure pulse dilated and contracted the fracture. Field data were analyzed through hydraulic and coupled hydromechanical simulations using different governing flow laws. In matching the time lag between the pressure peaks at the two measuring points, our hydraulic models indicated that (1) flow was channeled in the fracture, (2) the hydraulic conductivity tensor was highly anisotropic, and (3) the radius of pulse influence was asymmetric, in that the pulse travelled faster vertically than horizontally. Moreover, our parametric study demonstrated that the fluid pressure diffusion through the fracture was quite sensitive to the spacing and orientation of channels, hydraulic aperture, storativity and hydraulic conductivity. Comparison between hydraulic and hydromechanical models showed that the deformation significantly affected fracture permeability and storativity, and consequently, the fluid pressure propagation, suggesting that the simultaneous measurements of pressure and mechanical displacement signals could substantially improve the interpretation of pulse tests during reservoir characterization.

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

2008-03-16T23:59:59.000Z

156

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

157

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

158

Fracture-Induced Anisotropic Attenuation  

E-Print Network [OSTI]

simplicity. The expanded fracture compliance matrix of each set is. Sf ¼ s11 s12. 0 ..... ?59?. (in MPa), where q = 2,300 kg/m3, e.g., c11 = 23 GPa . We assume a ...

2012-03-23T23:59:59.000Z

159

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

160

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

Note: This page contains sample records for the topic "improves fracture length" 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

A new failure mechanism in thin film by collaborative fracture and delamination: interacting duos of cracks  

E-Print Network [OSTI]

When a thin film moderately adherent to a substrate is subjected to residual stress, the cooperation between fracture and delamination leads to unusual fracture patterns such as spirals, alleys of crescents and various types of strips, all characterized by a robust characteristic length scale. We focus on the propagation of a duo of cracks: two fractures in the film connected by a delamination front and progressively detaching a strip. We show experimentally that the system selects an equilibrium width on the order of 25 times the thickness of the coating and independent of both fracture and adhesion energies. We investigate numerically the selection of the width and the condition for propagation by considering Griffith's criterion and the principle of local symmetry. In addition, we propose a simplified model based on maximum of energy release rate, which provides insights of the physical mechanisms leading to these regular patterns, and predicts the effect of material properties on the selected with of the detaching strip.

Joel Marthelot; Jose Bico; Francisco Melo; Benoit Roman

2014-12-02T23:59:59.000Z

162

Evaluation of Acid Fracturing Using the Method of Distributed Volumetric Sources  

E-Print Network [OSTI]

acid volume versus cumulative production with optimum fracture half length............................................................................................40 4.1 For Well SA-2, IPR and VLP curves shows production rates... at the beginning of production....................................................................................47 4.2 For Well SA-2, IPR & VLP curves shows production rates at the end of production history; the absolute open flow (AOF) of IPR is much less...

Lee, Jaehun

2010-01-14T23:59:59.000Z

163

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

164

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...

165

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...

166

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

167

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

168

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

169

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

170

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

171

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

172

Massive hydraulic fracture test Cotton Valley Lime East Texas. Final report, 8 August 1978-31 July 1980  

SciTech Connect (OSTI)

This report summarizes the results of an active stimulation program on the Cotton Valley Lime as evaluated using reservoir production and pressure transient data. Using standard economic parameters and reservoir permeabilities determined by history matching, a detailed study was made to determine the well spacing and fracture length radius necessary for optimum development of the Fallon and North Personville Fields. In addition, the major details of designing and executing a super massive hydraulic fracture job are discussed in the appendix.

Kozik, H.G.; Holditch, S.A.; Kumar, A.

1980-08-01T23:59:59.000Z

173

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

174

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

175

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

176

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

177

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

178

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

179

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

180

Harmonic experiments to model fracture induced anisotropy KAUST ...  

E-Print Network [OSTI]

May 9, 2012 ... hydrocarbon and geothermal reservoirs are mainly composed of fractured rocks. Harmonic experiments to model fracture induced anisotropy ...

santos,,,

Note: This page contains sample records for the topic "improves fracture length" 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

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...

182

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

E-Print Network [OSTI]

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

183

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

SciTech Connect (OSTI)

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

Not Available

1993-04-01T23:59:59.000Z

184

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

185

Self-potential observations during hydraulic fracturing  

E-Print Network [OSTI]

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

Moore, Jeffrey R.; Glaser, Steven D.

2008-01-01T23:59:59.000Z

186

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

187

Fluid Flow Simulation in Fractured Reservoirs  

E-Print Network [OSTI]

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

Sarkar, Sudipta

2002-01-01T23:59:59.000Z

188

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

189

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

190

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

191

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.

192

Discrete fracture modeling for fractured reservoirs using Voronoi grid blocks  

E-Print Network [OSTI]

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

Gross, Matthew Edward

2007-09-17T23:59:59.000Z

193

Wave Propagation in Fractured Poroelastic Media  

E-Print Network [OSTI]

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

194

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

195

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.

196

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.

197

Fractured shale reservoirs: Towards a realistic model  

SciTech Connect (OSTI)

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

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

1996-09-01T23:59:59.000Z

198

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.

199

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.

200

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.

Note: This page contains sample records for the topic "improves fracture length" 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

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

202

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

203

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

204

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

205

Fracture toughness for copper oxide superconductors  

DOE Patents [OSTI]

An oxide-based strengthening and toughening agent, such as tetragonal Zro.sub.2 particles, has been added to copper oxide superconductors, such as superconducting YBa.sub.2 Cu.sub.3 O.sub.x (123) to improve its fracture toughness (K.sub.IC). A sol-gel coating which is non-reactive with the superconductor, such as Y.sub.2 BaCuO.sub.5 (211) on the ZrO.sub.2 particles minimized the deleterious reactions between the superconductor and the toughening agent dispersed therethrough. Addition of 20 mole percent ZrO.sub.2 coated with 211 yielded a 123 composite with a K.sub.IC of 4.5 MPa(m).sup.0.5.

Goretta, Kenneth C. (Downers Grove, IL); Kullberg, Marc L. (Lisle, IL)

1993-01-01T23:59:59.000Z

206

Fracture toughness for copper oxide superconductors  

DOE Patents [OSTI]

An oxide-based strengthening and toughening agent, such as tetragonal ZrO[sub 2] particles, has been added to copper oxide superconductors, such as superconducting YBa[sub 2]Cu[sub 3]O[sub x] (123) to improve its fracture toughness (K[sub IC]). A sol-gel coating which is non-reactive with the superconductor, such as Y[sub 2]BaCuO[sub 5] (211) on the ZrO[sub 2] particles minimized the deleterious reactions between the superconductor and the toughening agent dispersed therethrough. Addition of 20 mole percent ZrO[sub 2] coated with 211 yielded a 123 composite with a K[sub IC] of 4.5 MPa(m)[sup 0.5].

Goretta, K.C.; Kullberg, M.L.

1993-04-13T23:59:59.000Z

207

Experimental and simulation study of improved oil recovery in shale formations.  

E-Print Network [OSTI]

??Shale has ultra low permeability and cannot produce without hydraulic fracturing to improve the contact between reservoir matrix with wellbore. In addition, shale production declines… (more)

Morsy, Samiha

2014-01-01T23:59:59.000Z

208

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

209

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

210

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

SciTech Connect (OSTI)

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

Gary Mavko

2004-11-30T23:59:59.000Z

211

Horizontal well will be employed in hydraulic fracturing research  

SciTech Connect (OSTI)

This paper reports on 10-well research site, planned to enable more controlled experiments for better definition of hydraulic fracturing. One of the 10 wells will be a near-horizontal well that will monitor microseismic events along its length. The Gas Research Institute (GR) has begun evaluating a low-permeability, gas-bearing sandstone as the target stratum for experiments to be conducted at its hydraulic fracture test site (HFTS). During a 4-year period, GRI will use the HFTS as a field laboratory to conduct multi-disciplinary research projects to assess the mechanics of hydraulic fracturing. As a result of a screening process the Davis sandstone in the Ft. Worth basin has emerged as the tight gas sand which best fits the selected criteria established by GRI and its contractors, GRI says. The Ft. Worth basin is located approximately 50 miles northwest of Ft. Worth. GRI is planning a research well to fully characterize the Davis prior to making a final decision on the location of the HFTS. If data from the research well indicate the Davis sand does not adequately meet selection criteria, other candidates identified in the screening process will be investigated.

Not Available

1991-05-20T23:59:59.000Z

212

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

213

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

214

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

215

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

SciTech Connect (OSTI)

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

Nakagawa, S.; Myer, L.R.

2009-06-15T23:59:59.000Z

216

Acid Fracture and Fracture Conductivity Study of Field Rock Samples  

E-Print Network [OSTI]

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

Underwood, Jarrod

2013-11-15T23:59:59.000Z

217

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

SciTech Connect (OSTI)

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

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

1999-08-09T23:59:59.000Z

218

CONFORMANCE IMPROVEMENT USING GELS  

SciTech Connect (OSTI)

This technical progress report describes work performed from September 1, 2003, through February 29, 2004, for the project, ''Conformance Improvement Using Gels.'' We examined the properties of several ''partially formed'' gels that were formulated with a combination of high and low molecular weight HPAM polymers. After placement in 4-mm-wide fractures, these gels required about 25 psi/ft for brine to breach the gel (the best performance to date in fractures this wide). After this breach, stabilized residual resistance factors decreased significantly with increased flow rate. Also, residual resistance factors were up to 9 times greater for water than for oil. Nevertheless, permeability reduction factors were substantial for both water and oil flow. Gel with 2.5% chopped fiberglass effectively plugged 4-mm-wide fractures if a 0.5-mm-wide constriction was present. The ability to screen-out at a constriction appears crucial for particulate incorporation to be useful in plugging fractures. In addition to fiberglass, we examined incorporation of polypropylene fibers into gels. Once dispersed in brine or gelant, the polypropylene fibers exhibited the least gravity segregation of any particulate that we have tested to date. In fractures with widths of at least 2 mm, 24-hr-old gels (0.5% high molecular weight HPAM) with 0.5% fiber did not exhibit progressive plugging during placement and showed extrusion pressure gradients similar to those of gels without the fiber. The presence of the fiber roughly doubled the gel's resistance to first breach by brine flow. The breaching pressure gradients were not as large as for gels made with high and low molecular weight polymers (mentioned above). However, their material requirements and costs (i.e., polymer and/or particulate concentrations) were substantially lower than for those gels. A partially formed gel made with 0.5% HPAM did not enter a 0.052-mm-wide fracture when applying a pressure gradient of 65 psi/ft. This result suggests a lower limit of fracture width for entry of formed or partially formed gels (when reasonable pressure gradients are applied). In unfractured porous rock, we investigated the time dependence of oil and water permeabilities during various cycles of oil and water injection after placement of a Cr(III)-acetate-HPAM gel. Permeability to water stabilized rapidly (within 1 pore volume, PV), while permeability to oil stabilized gradually over the course of 100 PV. The behavior was surprisingly insensitive to core material (strongly water-wet Berea sandstone and strongly oil-wet porous polyethylene), core permeability (740 to 10,000 md), and applied pressure gradient (10 to 100 psi/ft).

Randall S. Seright

2004-03-01T23:59:59.000Z

219

Laboratory Study to Identify the Impact of Fracture Design Parameters over the Final Fracture Conductivity Using the Dynamic Fracture Conductivity Test Procedure  

E-Print Network [OSTI]

such as closure stress, and temperature and fracture fluid parameters such as proppant loading over the final conductivity of a hydraulic fracture treatment. With the purpose of estimating the relation between fracture conductivity and the design parameters, two...

Pieve La Rosa, Andres Eduardo

2011-08-08T23:59:59.000Z

220

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

Note: This page contains sample records for the topic "improves fracture length" 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

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

SciTech Connect (OSTI)

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

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

1994-08-01T23:59:59.000Z

222

Molecular-To-Continuum Fracture Analysis of Thermosetting Polymer/Solid Interfaces  

SciTech Connect (OSTI)

This report focuses on the relationship between the fundamental interactions acting across an interface and macroscopic engineering observable such as fracture toughness or fracture stress. The work encompasses experiment, theory, and simulation. The model experimental system is epoxy on polished silicon. The interfacial interactions between the substrate and the adhesive are varied continuously using self-assembling monolayer. Fracture is studied in two specimen geometries: a napkin-ring torsion geometry and a double cantilevered beam specimen. Analysis and modeling involves molecular dynamics simulations and continuum mechanics calculations. Further insight is gained from analysis of measurements in the literature of direct force measurements for various fundamental interactions. In the napkin-ring test, the data indicate a nonlinear relationship between interface strength and fracture stress. In particular, there is an abrupt transition in fracture stress which corresponds to an adhesive-to-cohesive transition. Such nonlinearity is not present in the MD simulations on the tens-of-nanometer scale, which suggests that the nonlinearity comes from bulk material deformation occurring on much larger length scales. We postulate that the transition occurs when the interface strength becomes comparable to the yield stress of the material. This postulate is supported by variation observed in the fracture stress curve with test temperature. Detailed modeling of the stress within the sample has not yet been attempted. In the DCB test, the relationship between interface strength and fracture toughness is also nonlinear, but the fracture mechanisms are quite different. The fracture does not transition from adhesive to cohesive, but remains adhesive over the entire range of interface strength. This specimen is modeled quantitatively by combining (i) continuum calculations relating fracture toughness to the stress at 90 {angstrom} from the crack tip, and (ii) a relationship from molecular simulations between fracture stress on a {approx} 90 {angstrom} scale and the fraction of surface sites which chemically bond. The resulting relationship between G{sub c} and fraction of bonding sites is then compared to the experimental data. This first order model captures the nonlinearity in the experimentally-determined relationship. A much more extensive comparison is needed (calculations extending to higher G{sub c} values, experimental data extending to lower G{sub c} values) to guide further model development.

KENT,MICHAEL S.; REEDY JR.,EARL DAVID; STEVENS,MARK J.

2000-01-01T23:59:59.000Z

223

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

224

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

225

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

226

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

227

Hydraulic Fracturing Data Collection Tools Improve Environmental Reporting,  

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

AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE:1 First Use of Energy for All Purposes (Fuel and Nonfuel),Feet) Year Jan Feb Mar Apr May Jun Jul(Summary) "ofEarly Career Scientists'Montana.ProgramJulietip sheetK-4In 2013Department ofThis brieftheEnergyMonitoring,

228

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

229

Wave Propagation in Fractured Poroelastic Media  

E-Print Network [OSTI]

Wave Propagation in Fractured. Poroelastic Media. WCCM, Barcelona, Spain, July 2014. Juan E. Santos,. 1. 1. Instituto del Gas y del Petr´oleo (IGPUBA), UBA,

2014-06-22T23:59:59.000Z

230

Fracture permeability and seismic wave scattering ŒPoroelastic ...  

E-Print Network [OSTI]

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

Seiji Nakagawa

2010-02-03T23:59:59.000Z

231

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...

232

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...

233

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...

234

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...

235

Microseismic Tracer Particles for Hydraulic Fracturing  

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

can be discriminateddetected 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...

236

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...

237

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...

238

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

239

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

240

Characterization of EGS Fracture Network Lifecycles  

SciTech Connect (OSTI)

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

Gillian R. Foulger

2008-03-31T23:59:59.000Z

Note: This page contains sample records for the topic "improves fracture length" 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

3-D Reservoir and Stochastic Fracture Network Modeling for Enhanced Oil Recovery, Circle Ridge Phosphoria/Tensleep Reservoir, and River Reservation, Arapaho and Shoshone Tribes, Wyoming  

SciTech Connect (OSTI)

The goal of this project is to improve the recovery of oil from the Circle Ridge Oilfield, located on the Wind River Reservation in Wyoming, through an innovative integration of matrix characterization, structural reconstruction, and the characterization of the fracturing in the reservoir through the use of discrete fracture network models.

La Pointe, Paul; Parney, Robert; Eiben, Thorsten; Dunleavy, Mike; Whitney, John; Eubanks, Darrel

2002-09-09T23:59:59.000Z

242

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

243

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.

244

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

245

Ductile fracture modeling : theory, experimental investigation and numerical verification  

E-Print Network [OSTI]

The fracture initiation in ductile materials is governed by the damaging process along the plastic loading path. A new damage plasticity model for ductile fracture is proposed. Experimental results show that fracture ...

Xue, Liang, 1973-

2007-01-01T23:59:59.000Z

246

Numerical simulation of hydraulic fracturing  

E-Print Network [OSTI]

of Eq. 21, in its present form, is unstable. The change in fracture cell volume over the time step, BV/At, must be known to calculate pressures at the new time level. Since the value of the AV/At term is dependent on the pressure being solved for... is unconditionally stable and, therefore, guarantees a solution for any time step size~s. To implicitly expand the AV/At term, the pressure change component Ap /At must be extracted so that pex(t+At) can be placed ex on the left hand side of Eq. 21. The AV...

Warner, Joseph Barnes

1987-01-01T23:59:59.000Z

247

Linear elastic fracture mechanics predicts the propagation distance of frictional slip  

E-Print Network [OSTI]

When a frictional interface is subject to a localized shear load, it is often (experimentally) observed that local slip events initiate at the stress concentration and propagate over parts of the interface by arresting naturally before reaching the edge. We develop a theoretical model based on linear elastic fracture mechanics to describe the propagation of such precursory slip. The model's prediction of precursor lengths as a function of external load is in good quantitative agreement with laboratory experiments as well as with dynamic simulations, and provides thereby evidence to recognize frictional slip as a fracture phenomenon. We show that predicted precursor lengths depend, within given uncertainty ranges, mainly on the kinetic friction coefficient, and only weakly on other interface and material parameters. By simplifying the fracture mechanics model we also reveal sources for the observed non-linearity in the growth of precursor lengths as a function of the applied force. The discrete nature of precursors as well as the shear tractions caused by frustrated Poisson's expansion are found to be the dominant factors. Finally, we apply our model to a different, symmetric set-up and provide a prediction of the propagation distance of frictional slip for future experiments.

David S. Kammer; Mathilde Radiguet; Jean-Paul Ampuero; Jean-François Molinari

2014-08-18T23:59:59.000Z

248

Fracturing alliance allows massive diatomite oil reserves to be economically produced at Lost Hills, California: A case study  

SciTech Connect (OSTI)

As North American oilfield operations mature, there is a perceptible loosening of the autocratic ties between oil companies and contractors. They are being replaced by alliances or partnerships designed to minimize cost while improving profitability of the companies involved. Many papers have been written concerning alliance theory, but little documentation exists detailing actual performance. This paper evaluates a mature alliance, its implementation, structure and results. In Lost Hills, California, the diatomite formation requires hydraulic fracturing to allow oil recovery at profitable production rates. Because hydraulic fracturing is approximately two-thirds of the total well cost, it is imperative that fracturing investments be optimized to allow field development to proceed at optimum levels. Therefore, in 1990, a fracturing alliance (the first of its kind) was initiated between Chevron and Schlumberger Dowell. Over 1 billion lbm of sand has been successfully placed during approximately 2,000 fracture stimulation jobs. Through this prototype fracturing alliance, many major accomplishments are being achieved. The most notable are the hydraulic fracturing costs that have been reduced by 40% while improving the profitability of both companies. This paper illustrates the benefits of an alliance and justifies the change in management style from a low-bid operating strategy to a win-win customer/supplier attitude.

Klins, M.A.; Stewart, D.W.; Pferdehirt, D.J.; Stewart, M.E.

1995-12-31T23:59:59.000Z

249

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

E-Print Network [OSTI]

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

Tao, Qingfeng

2010-07-14T23:59:59.000Z

250

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

E-Print Network [OSTI]

program. The main contributions of this work are: An optimal fracture design methodology called unified fracture design (UFD) is presented and damage effects are considered in the optimal design calculation. As a by-product of UFD, a fracture evaluation...

Wang, Wenxin

2006-04-12T23:59:59.000Z

251

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

252

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

253

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...

254

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 *...

255

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...

256

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...

257

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...

258

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...

259

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...

260

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...

Note: This page contains sample records for the topic "improves fracture length" 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

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...

262

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...

263

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...

264

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 *...

265

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...

266

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...

267

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....

268

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...

269

Poroelastic modeling of seismic boundary conditions across a fracture  

E-Print Network [OSTI]

Permeability of a fracture can affect how the fracture interacts with seismic waves. ... characteristic parameters that control the seismic response of single ...

2007-07-20T23:59:59.000Z

270

Finite Conductivity Fractures in Elliptical Coordinates  

E-Print Network [OSTI]

TO THE DEPARTMENT OF PETROLEUM ENGINEERING AND THE COMMITTEE ON GRADUATE STUDIES OF STANFORD UNIVERSITY IN PARTIAL well performance. Indeed, a large number of wells, which could not otherwise be operated economically, it is important that means be available to evaluate fracture effectiveness. The most widely used tool in fracture

Stanford University

271

Fracture Conductivity of the Eagle Ford Shale  

E-Print Network [OSTI]

such as the Eagle Ford Shale. This work investigates the fracture conductivities of seven Eagle Ford Shale samples collected from an outcrop of facies B. Rough fractures were induced in the samples and laboratory experiments that closely followed the API RP-61...

Guzek, James J

2014-07-25T23:59:59.000Z

272

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

273

Effect of Minimal lengths on Electron Magnetism  

E-Print Network [OSTI]

We study the magnetic properties of electron in a constant magnetic field and confined by a isotropic two dimensional harmonic oscillator on a space where the coordinates and momenta operators obey generalized commutation relations leading to the appearance of a minimal length. Using the momentum space representation we determine exactly the energy eigenvalues and eigenfunctions. We prove that the usual degeneracy of Landau levels is removed by the presence of the minimal length in the limits of weak and strong magnetic field.The thermodynamical properties of the system, at high temperature, are also investigated showing a new magnetic behavior in terms of the minimal length.

Khireddine Nouicer

2007-07-13T23:59:59.000Z

274

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

275

A length operator for canonical quantum gravity  

E-Print Network [OSTI]

We construct an operator that measures the length of a curve in four-dimensional Lorentzian vacuum quantum gravity. We work in a representation in which a $SU(2)$ connection is diagonal and it is therefore surprising that the operator obtained after regularization is densely defined, does not suffer from factor ordering singularities and does not require any renormalization. We show that the length operator admits self-adjoint extensions and compute part of its spectrum which like its companions, the volume and area operators already constructed in the literature, is purely discrete and roughly is quantized in units of the Planck length. The length operator contains full and direct information about all the components of the metric tensor which faciliates the construction of a new type of weave states which approximate a given classical 3-geometry.

T. Thiemann

1996-06-29T23:59:59.000Z

276

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

277

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

278

The K+ K+ scattering length from Lattice QCD  

SciTech Connect (OSTI)

The K+K+ scattering length is calculated in fully-dynamical lattice QCD with domain-wall valence quarks on the MILC asqtad-improved gauge configurations with fourth-rooted staggered sea quarks. Three-flavor mixed-action chiral perturbation theory at next-to-leading order, which includes the leading effects of the finite lattice spacing, is used to extrapolate the results of the lattice calculation to the physical value of mK + /fK + . We find mK^+ aK^+ K^+ = â~0.352 ± 0.016, where the statistical and systematic errors have been combined in quadrature.

Silas Beane; Thomas Luu; Konstantinos Orginos; Assumpta Parreno; Martin Savage; Aaron Torok; Andre Walker-Loud

2007-09-11T23:59:59.000Z

279

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.

280

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

Note: This page contains sample records for the topic "improves fracture length" 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

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

282

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

283

Absorption Lengths in the Holographic Plasma  

E-Print Network [OSTI]

We consider the effect of a periodic perturbation with frequency $\\omega$ on the holographic N=4 plasma represented by the planar AdS black hole. The response of the system is given by exponentially decaying waves. The corresponding complex wave numbers can be found by solving wave equations in the AdS black hole background with infalling boundary conditions on the horizon in an analogous way as in the calculation of quasinormal modes. The complex momentum eigenvalues have an interpretation as poles of the retarded Green's functions, where the inverse of the imaginary part gives an absorption length $\\lambda$. At zero frequency we obtain the screening length for a static field. These are directly related to the glueball masses in the dimensionally reduced theory. We also point out that the longest screening length corresponds to an operator with non-vanishing R-charge and thus does not have an interpretation as a QCD3 glueball.

Irene Amado; Carlos Hoyos; Karl Landsteiner; Sergio Montero

2007-07-11T23:59:59.000Z

284

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

285

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

286

Sighting optics including an optical element having a first focal length and a second focal length  

DOE Patents [OSTI]

One embodiment of sighting optics according to the teachings provided herein may include a front sight and a rear sight positioned in spaced-apart relation. The rear sight includes an optical element having a first focal length and a second focal length. The first focal length is selected so that it is about equal to a distance separating the optical element and the front sight and the second focal length is selected so that it is about equal to a target distance. The optical element thus brings into simultaneous focus, for a user, images of the front sight and the target.

Crandall, David Lynn (Idaho Falls, ID)

2011-08-01T23:59:59.000Z

287

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

288

Percutaneous Vertebroplasty for Osteoporotic Compression Fracture: Multivariate Study of Predictors of New Vertebral Body Fracture  

SciTech Connect (OSTI)

Purpose. To investigate the risk factors and relative risk of new compression fractures following vertebroplasty. Methods. Initially, we enrolled 104 consecutive patients with vertebral compression fractures caused by osteoporosis. A total of 83 of the 104 patients visited our hospital for follow-up examinations for more than 4 weeks after vertebroplasty. Logistic regression analysis of the data obtained from these 83 patients was used to determine relative risks of recurrent compression fractures, using 13 different factors. Results. We identified 59 new fractures in 30 of the 83 patients: 41 new fractures in vertebrae adjacent to treated vertebrae; and 18 new fractures in vertebrae not adjacent to treated vertebrae. New fractures occurred in vertebrae adjacent to treated vertebrae significantly more frequently than in vertebrae not adjacent to treated vertebrae. Only cement leakage into the disk was a significant predictor of new vertebral body fracture after vertebroplasty (odds ratio = 4.633). None of the following covariates were associated with increased risk of new fracture: age, gender, bone mineral density, the number of vertebroplasty procedures, the number of vertebrae treated per procedure, the cumulative number of vertebrae treated, the presence of a single untreated vertebra between treated vertebrae, the presence of multiple untreated vertebrae between treated vertebrae, the amount of bone cement injected per procedure, the cumulative amount of bone cement injected, cement leakage into the soft tissue around the vertebra, and cement leakage into the vein.

Komemushi, Atsushi, E-mail: kome64@yo.rim.or.jp; Tanigawa, Noboru; Kariya, Shuji; Kojima, Hiroyuki; Shomura, Yuzo [Kansai Medical University, Department of Radiology (Japan); Komemushi, Sadao [Kinki University, Schoool of Agriculture (Japan); Sawada, Satoshi [Kansai Medical University, Department of Radiology (Japan)

2006-08-15T23:59:59.000Z

289

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

290

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.

291

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

292

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

293

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

294

Inheritance of Cotton Fiber Length and Strength  

E-Print Network [OSTI]

. Frequency distribution of upper half mean length (UHML) in the P1, P2, F1, BC1P1, BC1P2, and F2 generations for the parental combination of ELS33 (P1) x SID84 (P2) in 2010 and 2011. ..................................................... 63 Figure 4.... Frequency distribution of upper half mean length (UHML) in the P1, P2, F1, BC1P1, BC1P2, and F2 generations for the parental combination of ELS33 (P1) x HS624 (P2) in 2010 and 2011. ................................................................. 64...

Joy, Kolbyn Seth

2014-04-23T23:59:59.000Z

295

Apparatus for fabricating continuous lengths of superconductor  

DOE Patents [OSTI]

A process and apparatus for manufacturing a superconductor. The process is accomplished by depositing a superconductor precursor powder on a continuous length of a first substrate ribbon, overlaying a continuous length of a second substrate ribbon on said first substrate ribbon, and applying sufficient pressure to form a bound layered superconductor comprising a layer of said superconducting precursor powder between said first substrate ribbon and said second substrates ribbon. The layered superconductor is then heat treated to establish the superconducting phase of said superconductor precursor powder.

Kroeger, Donald M. (Knoxville, TN); List, III, Frederick A. (Andersonville, TN)

2002-01-01T23:59:59.000Z

296

Apparatus for fabricating continuous lengths of superconductor  

DOE Patents [OSTI]

A process and apparatus for manufacturing a superconductor. The process is accomplished by depositing a superconductor precursor powder on a continuous length of a first substrate ribbon, overlaying a continuous length of a second substrate ribbon on said first substrate ribbon, and applying sufficient pressure to form a bound layered superconductor comprising a layer of said superconducting precursor powder between said first substrate ribbon and said second substrates ribbon. The layered superconductor is then heat treated to establish the superconducting phase of said superconductor precursor powder.

Kroeger, Donald M. (Knoxville, TN); List, III, Frederick A. (Andersonville, TN)

2001-01-01T23:59:59.000Z

297

Crystal diffraction lens with variable focal length  

DOE Patents [OSTI]

A method and apparatus for altering the focal length of a focusing element of one of a plurality of pre-determined focal lengths by changing heat transfer within selected portions of the element by controlled quantities is disclosed. Control over heat transfer is accomplished by manipulating one or more of a number of variables, including: the amount of heat or cold applied to surfaces; type of fluids pumped through channels for heating and cooling; temperatures, directions of flow and rates of flow of fluids; and placement of channels. 19 figures.

Smither, R.K.

1991-04-02T23:59:59.000Z

298

A regional-scale particle-tracking method for nonstationary fractured media  

SciTech Connect (OSTI)

A regional scale transport model is introduced that is applicable to non-stationary and statistically inhomogeneous fractured media, provided that hydraulic flow, but not necessarily solute transport, can be approximated by equivalent continuum properties at some block scale. Upscaled flow and transport block properties are transferred from multiple fracture network realizations to a regional model with grid elements of equal size to that found valid for continuum approximation of flow. In the large-scale model, flow is solved in a stochastic continuum framework, whereas the transport calculations employ a random walk procedure. Block-wise transit times are sampled from distributions linked to each block-conductivity based on its underlying fracture network. To account for channeled transport larger than the block scale, several alternatives in sampling algorithm are introduced and compared. The most reasonable alternative incorporates a spatial persistence length in sampling the particle transit times; this tracer transport persistence length is related to interblock channeling, and is quantified by the number N of blocks. The approach is demonstrated for a set of field data, and the obtained regional-scale particle breakthroughs are analyzed. These are fitted to the one-dimensional advective-dispersive equation to determine an effective macroscale dispersion coefficient. An interesting finding is that this macroscale dispersion coefficient is found to be a linear function of the transport persistence, N, with a slope equal to a representative mean block-scale dispersion coefficient and a constant that incorporates background dispersion arising from the regional heterogeneous conductivity field.

Ohman, Johan; Niemi, Auli; Tsang, Chin-Fu

2004-11-01T23:59:59.000Z

299

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

300

Fracture of Thermosetting Polymers: Experiments and Modeling  

E-Print Network [OSTI]

for the designation as UNDERGRADUATE RESEARCH SCHOLAR A Senior Scholars Thesis by BRAD EVIN BURGESS FRACTURE OF THERMOSETTING POLYMERS: EXPERIMENTS AND MODELING Approved by: Research Advisor: Amine Benzerga Associate Dean for Undergraduate... Scholars Thesis by BRAD EVIN BURGESS iii ABSTRACT Fracture of Thermosetting Polymers: Experiments and Modeling. (April 2009) Brad Evin Burgess Department of Aerospace Engineering Texas A&M University Research Advisor: Dr. Amine Benzerga...

Benzerga, Amine; Burgess, Brad

2011-08-04T23:59:59.000Z

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


301

FRACTURE TOUGHNESS VARIABILITY IN F82H  

SciTech Connect (OSTI)

The fracture toughness database for F82H displays some anomalous behavior. Metallographic examination reveals banding in the center of 25 mm thick F82H plate, which is more evident in transverse section. The banding is shown to arise because some grains are etched on a very fine scale whereas the remainder is etched more strongly and better delineates the martensite lath structure. However, the banding found does not provide explanation for the anomalous fracture toughness behavior.

Gelles, David S.; Sokolov, M.

2003-09-03T23:59:59.000Z

302

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

303

Identification of parameters influencing the response of gas storage wells to hydraulic fracturing with the aid of a neural network  

SciTech Connect (OSTI)

Performing hydraulic fractures on gas storage wells to improve their deliverability is a common practice in the eastern part of the US. Most fields used for storage in this region are old, and the reservoir characteristic data necessary for most reservoir studies and hydraulic fracture design and evaluation are scarce. This paper introduces a new method by which parameters that influence the response of gas storage wells to hydraulic fracturing may be identified in the absence of sufficient reservoir data. Control and manipulation of these parameters, once identified correctly, could enhance the outcome of frac jobs in gas storage fields. The authors conducted the study on a gas storage field in the Clinton formation of northeastern Ohio. They found that well-performance indicators before a hydraulic fracture play an important role in how good the well will respond to a new frac job. They also identified several other important factors. The identification of controlling parameters serves as a foundation for improved frac job design in the fields where adequate engineering data are not available. Another application of this type of study could be the enhancement of selection criteria among the candidate wells for hydraulic fracturing. To achieve the objective of this study, the authors designed, trained, and applied an artificial neural network. The paper will discuss the results of the incorporation of this new technology in hydraulic fracture design and evaluation.

McVey, D.S. [East Ohio Gas Co., North Canton, OH (United States); Mohaghegh, S.; Aminian, K.; Ameri, S. [West Virginia Univ., Morgantown, WV (United States)

1996-04-01T23:59:59.000Z

304

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

305

Identification of parameters influencing the response of gas storage wells to hydraulic fracturing with the aid of a neural network  

SciTech Connect (OSTI)

Performing hydraulic fractures on gas storage wells to improve their deliverability is a common practice in the eastern part of the United States. Most of the fields in this part of the country being used for storage are old. Reservoir characteristic data necessary for most reservoir studies and hydraulic fracture design and evaluation are scarce for these old fields. This paper introduces a new methodology by which parameters that influence the response of gas storage wells to hydraulic fracturing may be identified in the absence of sufficient reservoir data. Control and manipulation of these parameters, once identified correctly, could enhance the outcome of frac jobs in gas storage fields. The study was conducted on a gas storage field in the Clinton formation of Northeastern Ohio. It was found that well performance indicators prior to a hydraulic fracture play an important role in how good the well will respond to a new frac job. Several other important factors were also identified.

McVey, D.S.; Mohaghegh, S.; Aminian, K.

1994-12-31T23:59:59.000Z

306

Improved Microseismicity Detection During Newberry EGS Stimulations  

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

Effective enhanced geothermal systems (EGS) require optimal fracture networks for efficient heat transfer between hot rock and fluid. Microseismic mapping is a key tool used to infer the subsurface fracture geometry. Traditional earthquake detection and location techniques are often employed to identify microearthquakes in geothermal regions. However, most commonly used algorithms may miss events if the seismic signal of an earthquake is small relative to the background noise level or if a microearthquake occurs within the coda of a larger event. Consequently, we have developed a set of algorithms that provide improved microearthquake detection. Our objective is to investigate the microseismicity at the DOE Newberry EGS site to better image the active regions of the underground fracture network during and immediately after the EGS stimulation. Detection of more microearthquakes during EGS stimulations will allow for better seismic delineation of the active regions of the underground fracture system. This improved knowledge of the reservoir network will improve our understanding of subsurface conditions, and allow improvement of the stimulation strategy that will optimize heat extraction and maximize economic return.

Templeton, Dennise

307

Improved Microseismicity Detection During Newberry EGS Stimulations  

SciTech Connect (OSTI)

Effective enhanced geothermal systems (EGS) require optimal fracture networks for efficient heat transfer between hot rock and fluid. Microseismic mapping is a key tool used to infer the subsurface fracture geometry. Traditional earthquake detection and location techniques are often employed to identify microearthquakes in geothermal regions. However, most commonly used algorithms may miss events if the seismic signal of an earthquake is small relative to the background noise level or if a microearthquake occurs within the coda of a larger event. Consequently, we have developed a set of algorithms that provide improved microearthquake detection. Our objective is to investigate the microseismicity at the DOE Newberry EGS site to better image the active regions of the underground fracture network during and immediately after the EGS stimulation. Detection of more microearthquakes during EGS stimulations will allow for better seismic delineation of the active regions of the underground fracture system. This improved knowledge of the reservoir network will improve our understanding of subsurface conditions, and allow improvement of the stimulation strategy that will optimize heat extraction and maximize economic return.

Templeton, Dennise

2013-11-01T23:59:59.000Z

308

Improved Microseismicity Detection During Newberry EGS Stimulations  

SciTech Connect (OSTI)

Effective enhanced geothermal systems (EGS) require optimal fracture networks for efficient heat transfer between hot rock and fluid. Microseismic mapping is a key tool used to infer the subsurface fracture geometry. Traditional earthquake detection and location techniques are often employed to identify microearthquakes in geothermal regions. However, most commonly used algorithms may miss events if the seismic signal of an earthquake is small relative to the background noise level or if a microearthquake occurs within the coda of a larger event. Consequently, we have developed a set of algorithms that provide improved microearthquake detection. Our objective is to investigate the microseismicity at the DOE Newberry EGS site to better image the active regions of the underground fracture network during and immediately after the EGS stimulation. Detection of more microearthquakes during EGS stimulations will allow for better seismic delineation of the active regions of the underground fracture system. This improved knowledge of the reservoir network will improve our understanding of subsurface conditions, and allow improvement of the stimulation strategy that will optimize heat extraction and maximize economic return.

Templeton, Dennise

2013-10-01T23:59:59.000Z

309

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

SciTech Connect (OSTI)

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

B.M. Freifeild

2001-10-18T23:59:59.000Z

310

Security analysis of the decoy method with the Bennett-Brassard 1984 protocol for finite key lengths  

E-Print Network [OSTI]

This paper provides a formula for the sacrifice bit-length for privacy amplification with the Bennett-Brassard 1984 protocol for finite key lengths when we employ the decoy method. Using the formula, we can guarantee the security parameter for realizable quantum key distribution system. The key generation rates with finite key lengths are numerically evaluated. The proposed method improves the existing key generation rate even in the asymptotic setting.

Masahito Hayashi; Ryota Nakayama

2013-11-19T23:59:59.000Z

311

Modeling interfacial fracture in Sierra.  

SciTech Connect (OSTI)

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

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

2013-09-01T23:59:59.000Z

312

EA Systems Examples Induction and Recursion Length Measuring the Universe Analysis Number systems of different lengths,  

E-Print Network [OSTI]

EA Systems Examples Induction and Recursion Length Measuring the Universe Analysis Number systems of Mathematics University of Bristol April 21, 2008 Richard.Pettigrew@bris.ac.uk Natural number systems and infinitesimal analysis #12;EA Systems Examples Induction and Recursion Length Measuring the Universe Analysis

Forster, T.E.

313

Identifying Fracture Types and Relative Ages Using Fluid Inclusion Stratigraphy  

SciTech Connect (OSTI)

Enhanced Geothermal Systems (EGS) are designed to recover heat from the subsurface by mechanically creating fractures in subsurface rocks. Understanding the life cycle of a fracture in a geothermal system is fundamental to the development of techniques for creating fractures. Recognizing the stage of a fracture, whether it is currently open and transmitting fluids; if it recently has closed; or if it is an ancient fracture would assist in targeting areas for further fracture stimulation. Identifying dense fracture areas as well as large open fractures from small fracture systems will also assist in fracture stimulation selection. Geothermal systems are constantly generating fractures, and fluids and gases passing through rocks in these systems leave small fluid and gas samples trapped in healed microfractures. Fluid inclusions trapped in minerals as the fractures heal are characteristic of the fluids that formed them, and this signature can be seen in fluid inclusion gas analysis. Our hypothesis is that fractures over their life cycle have different chemical signatures that we can see in fluid inclusion gas analysis and by using the new method of fluid inclusion stratigraphy (FIS) the different stages of fractures, along with an estimate of fracture size can be identified during the well drilling process. We have shown with this study that it is possible to identify fracture locations using FIS and that different fractures have different chemical signatures however that signature is somewhat dependent upon rock type. Open, active fractures correlate with increase concentrations of CO2, N2, Ar, and to a lesser extent H2O. These fractures would be targets for further enhancement. The usefulness of this method is that it is low cost alternative to current well logging techniques and can be done as a well is being drilled.

Dilley, Lorie M.; Norman, David; Owens, Lara

2008-06-30T23:59:59.000Z

314

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

315

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

316

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

317

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

318

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

319

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

320

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,...

Note: This page contains sample records for the topic "improves fracture length" 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

Self-replicating cracks: a collaborative fracture mode in thin films  

E-Print Network [OSTI]

Straight cracks are observed in thin coatings under residual tensile stress, resulting into the classical network pattern observed in china crockery, old paintings or dry mud. Here, we present a novel fracture mechanism where delamination and propagation occur simultaneously, leading to the spontaneous self-replication of an initial template. Surprisingly, this mechanism is active below the standard critical tensile load for channel cracks and selects a robust interaction length scale on the order of 30 times the film thickness. Depending on triggering mechanisms, crescent alleys, spirals or long bands are generated over a wide range of experimental parameters. We describe with a simple physical model the selection of the fracture path and provide a configuration diagram displaying the different failure modes.

Joel Marthelot; Benoit Roman; Jose Bico; Jeremie Teisseire; Davy Dalmas; Francisco Melo

2014-08-20T23:59:59.000Z

322

Length dependence of the Raman spectra of carbon nanotubes  

E-Print Network [OSTI]

DNA-wrapping technology, combined with size-exclusion chromatography, have made possible the sorting of carbon nanotubes according to length. In particular, length sorted nanotube samples, with finite lengths approaching ...

Zare, Aurea Tucay

2009-01-01T23:59:59.000Z

323

Effect of dynamic monotonic and cyclic loading on fracture behavior for Japanese carbon steel pipe STS410  

SciTech Connect (OSTI)

The fracture behavior for Japanese carbon steel pipe STS410 was examined under dynamic monotonic and cyclic loading through a research program of International Piping Integrity Research Group (EPIRG-2), in order to evaluate the strength of pipe during the seismic event The tensile test and the fracture toughness test were conducted for base metal and TIG weld metal. Three base metal pipe specimens, 1,500mm in length and 6-inch diameter sch.120, were employed for a quasi-static monotonic, a dynamic monotonic and a dynamic cyclic loading pipe fracture tests. One weld joint pipe specimen was also employed for a dynamic cyclic loading test In the dynamic cyclic loading test, the displacement was controlled as applying the fully reversed load (R=-1). The pipe specimens with a circumferential through-wall crack were subjected four point bending load at 300C in air. Japanese STS410 carbon steel pipe material was found to have high toughness under dynamic loading condition through the CT fracture toughness test. As the results of pipe fracture tests, the maximum moment to pipe fracture under dynamic monotonic and cyclic loading condition, could be estimated by plastic collapse criterion and the effect of dynamic monotonic loading and cyclic loading was a little on the maximum moment to pipe fracture of the STS410 carbon steel pipe. The STS410 carbon steel pipe seemed to be less sensitive to dynamic and cyclic loading effects than the A106Gr.B carbon steel pipe evaluated in IPIRG-1 program.

Kinoshita, Kanji; Murayama, Kouichi; Ogata, Hiroyuki [and others

1997-04-01T23:59:59.000Z

324

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

325

Critical length limiting super-low friction  

E-Print Network [OSTI]

Since the demonstration of super-low friction (superlubricity) in graphite at nanoscale, one of the main challenges in the field of nano- and micro-mechanics was to scale this phenomenon up. A key question to be addressed is to what extent superlubricity could persist, and what mechanisms could lead to its failure. Here, using an edge-driven Frenkel-Kontorova model, we establish a connection between the critical length above which superlubricity disappears and both intrinsic material properties and experimental parameters. A striking boost in dissipated energy with chain length emerges abruptly due to a high-friction stick-slip mechanism caused by deformation of the slider leading to a local commensuration with the substrate lattice. We derived a parameter-free analytical model for the critical length that is in excellent agreement with our numerical simulations. Our results provide a new perspective on friction and nano-manipulation and can serve as a theoretical basis for designing nano-devices with super-low friction, such as carbon nanotubes.

Ming Ma; Andrea Benassi; Andrea Vanossi; Michael Urbakh

2015-01-02T23:59:59.000Z

326

A Nonlocal Peridynamic Plasticity Model for the Dynamic Flow and Fracture of Concrete.  

SciTech Connect (OSTI)

A nonlocal, ordinary peridynamic constitutive model is formulated to numerically simulate the pressure-dependent flow and fracture of heterogeneous, quasi-brittle ma- terials, such as concrete. Classical mechanics and traditional computational modeling methods do not accurately model the distributed fracture observed within this family of materials. The peridynamic horizon, or range of influence, provides a characteristic length to the continuum and limits localization of fracture. Scaling laws are derived to relate the parameters of peridynamic constitutive model to the parameters of the classical Drucker-Prager plasticity model. Thermodynamic analysis of associated and non-associated plastic flow is performed. An implicit integration algorithm is formu- lated to calculate the accumulated plastic bond extension and force state. The gov- erning equations are linearized and the simulation of the quasi-static compression of a cylinder is compared to the classical theory. A dissipation-based peridynamic bond failure criteria is implemented to model fracture and the splitting of a concrete cylinder is numerically simulated. Finally, calculation of the impact and spallation of a con- crete structure is performed to assess the suitability of the material and failure models for simulating concrete during dynamic loadings. The peridynamic model is found to accurately simulate the inelastic deformation and fracture behavior of concrete during compression, splitting, and dynamically induced spall. The work expands the types of materials that can be modeled using peridynamics. A multi-scale methodology for simulating concrete to be used in conjunction with the plasticity model is presented. The work was funded by LDRD 158806.

Vogler, Tracy; Lammi, Christopher James

2014-10-01T23:59:59.000Z

327

Simulations of The Dalles Dam Proposed Full Length Spillwall  

SciTech Connect (OSTI)

This report presents results of a computational fluid dynamics (CFD) modeling study to evaluatethe impacts of a full-length spillwall at The Dalles Dam. The full-length spillwall is being designed and evaluated as a structural means to improve tailrace egress and thus survival of juvenile fish passing through the spillway. During the course of this study, a full-length spillwall at Bays 6/7 and 8/9 were considered. The U.S. Army Corps of Engineers (USACE) has proposed extending the spillwall constructed in the stilling basin between spillway Bays 6 and 7 about 590 ft farther downstream. It is believed that the extension of the spillwall will improve egress conditions for downstream juvenile salmonids by moving them more rapidly into the thalweg of the river hence reducing their exposure to predators. A numerical model was created, validated, and applied the The Dalles Dam tailrace. The models were designed to assess impacts to flow, tailrace egress, navigation, and adult salmon passage of a proposed spill wall extension. The more extensive model validation undertaken in this study greatly improved our confidence in the numerical model to represent the flow conditions in The Dalles tailrace. This study used these validated CFD models to simulate the potential impacts of a spillwall extension for The Dalles Dam tailrace for two locations. We determined the following: (1)The construction of an extended wall (between Bays 6/7) will not adversely impact entering or exiting the navigation lock. Impact should be less if a wall were constructed between Bays 8/9. (2)The construction of a wall between Bays 6/7 will increase the water surface elevation between the wall and the Washington shore. Although the increased water surface elevation would be beneficial to adult upstream migrants in that it decreases velocities on the approach to the adult ladder, the increased flow depth would enhance dissolved gas production, impacting potential operations of the project because of water quality. A wall between Bays 8/9 should have a lesser impact as the confined spill would be across more bays and the relative flow constriction less. (3) The 405 kcfs case was used for the rapid assessment of flow conditions and hydraulic mechanisms that might be responsible for the unexpected erosion at the end of the shelf downstream of Bay 7.

Rakowski, Cynthia L.; Perkins, William A.; Richmond, Marshall C.; Serkowski, John A.

2008-02-25T23:59:59.000Z

328

Scaling of the critical free length for progressive unfolding of self-bonded graphene  

SciTech Connect (OSTI)

Like filled pasta, rolled or folded graphene can form a large nanocapsule surrounding a hollow interior. Use as a molecular carrier, however, requires understanding of the opening of such vessels. Here, we investigate a monolayer sheet of graphene as a theoretical trial platform for such a nanocapsule. The graphene is bonded to itself via aligned disulfide (S-S) bonds. Through theoretical analysis and atomistic modeling, we probe the critical nonbonded length (free length, L{sub crit}) that induces fracture-like progressive unfolding as a function of folding radius (R{sub i}). We show a clear linear scaling relationship between the length and radius, which can be used to determine the necessary bond density to predict mechanical opening/closing. However, stochastic dissipated energy limits any exact elastic formulation, and the required energy far exceeds the dissociation energy of the S-S bond. We account for the necessary dissipated kinetic energy through a simple scaling factor (?), which agrees well with computational results.

Kwan, Kenny; Cranford, Steven W., E-mail: s.cranford@neu.edu [Laboratory of Nanotechnology in Civil Engineering (NICE), Department of Civil and Environmental Engineering, Northeastern University, 400 Snell Engineering, 360 Huntington Avenue, Boston, Massachusetts 02115 (United States)

2014-05-19T23:59:59.000Z

329

OVERBURDEN PRESSURE AFFECTS FRACTURE APERTURE  

E-Print Network [OSTI]

in the Petroleum Recovery Research Center at the New Mexico Institute of Mining and Technology (NMIMT). He holds MS and PhD degrees in petroleum engineering from New Mexico Institute of Mining and Technology. He serves.S. Department of Energy-sponsored pilot project "Investigation of Efficiency Improvements During CO2 Injection

Schechter, David S.

330

Naturally fractured tight gas - gas reservoir detection optimization. Quarterly report, June 1, 1996--September 30, 1996  

SciTech Connect (OSTI)

This document contains the status report for the Naturally Fractured Tight Gas-Gas Reservoir Detection Optimization project for the contract period 9/30/93 to 3/31/97. Data from seismic surveys are analyzed for structural imaging of reflector units. The data were stacked using the new, improved statics and normal moveout velocities. The 3-D basin modeling effort is continuing with code development. The main activities of this quarter were analysis of fluid pressure data, improved sedimentary history, lithologic unit geometry reconstruction algorithm and computer module, and further improvement, verification, and debugging of the basin stress and multi-phase reaction transport module.

Maxwell, J.M.; Ortoleva, P.; Payne, D.; Sibo, W.

1996-11-15T23:59:59.000Z

331

IPIRG programs - advances in pipe fracture technology  

SciTech Connect (OSTI)

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

Wilkowski, G.; Olson, R.; Scott, P. [Batelle, Columbus, OH (United States)

1997-04-01T23:59:59.000Z

332

On the fracture toughness of advanced materials  

SciTech Connect (OSTI)

Few engineering materials are limited by their strength; rather they are limited by their resistance to fracture or fracture toughness. It is not by accident that most critical structures, such as bridges, ships, nuclear pressure vessels and so forth, are manufactured from materials that are comparatively low in strength but high in toughness. Indeed, in many classes of materials, strength and toughness are almost mutually exclusive. In the first instance, such resistance to fracture is a function of bonding and crystal structure (or lack thereof), but can be developed through the design of appropriate nano/microstructures. However, the creation of tough microstructures in structural materials, i.e., metals, polymers, ceramics and their composites, is invariably a compromise between resistance to intrinsic damage mechanisms ahead of the tip of a crack (intrinsic toughening) and the formation of crack-tip shielding mechanisms which principally act behind the tip to reduce the effective 'crack-driving force' (extrinsic toughening). Intrinsic toughening is essentially an inherent property of a specific microstructure; it is the dominant form of toughening in ductile (e.g., metallic) materials. However, for most brittle (e.g., ceramic) solids, and this includes many biological materials, it is largely ineffective and toughening conversely must be developed extrinsically, by such shielding mechanisms as crack bridging. From a fracture mechanics perspective, this results in toughening in the form of rising resistance-curve behavior where the fracture resistance actually increases with crack extension. The implication of this is that in many biological and high-strength advanced materials, toughness is developed primarily during crack growth and not for crack initiation. This is an important realization yet is still rarely reflected in the way that toughness is measured, which is invariably involves the use of single-value (crack-initiation) parameters such as the fracture toughness K{sub Ic}.

Launey, Maximilien E.; Ritchie, Robert O.

2008-11-24T23:59:59.000Z

333

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

E-Print Network [OSTI]

cooling of the fracture surfaces results in a significant opening of the fracture, which would influence the rate of geothermal

Wessling, S.

2009-01-01T23:59:59.000Z

334

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

335

FRACTURE AND HYDROLOGY DATA FROM FIELD STUDIES AT STRIPA, SWEDEN  

E-Print Network [OSTI]

An Approach to the Fracture Hydrology at Stripa, PreliminaryRocks. On Recent Trends in Hydrology, Special PublicationsDE86 013586 W FRACTURE AND HYDROLOGY DATA FROM FIELD STUDIES

Gale, J.E.

2010-01-01T23:59:59.000Z

336

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

337

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.

338

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

339

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

340

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

Note: This page contains sample records for the topic "improves fracture length" 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

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

342

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

343

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

344

Selection of fracture fluid for stimulating tight gas reservoirs  

E-Print Network [OSTI]

..........................................51 6 Water Fracture Fluid Description ..............................................................56 7 Gel Fracture Fluid Description ..................................................................56 8 Proppant Description... Based on Proppant Concentration ........................66 24 Cumulative Frequency Distribution for 3-Year Cumulative Gas Production for Both Groups and Both Treatments (Carthage...

Malpani, Rajgopal Vijaykumar

2007-04-25T23:59:59.000Z

345

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

346

Fracture Toughness Prediction for MWCNT Reinforced Ceramics  

SciTech Connect (OSTI)

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

Henager, Charles H.; Nguyen, Ba Nghiep

2013-09-01T23:59:59.000Z

347

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

348

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

349

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

350

Increasing LIGO sensitivity by feedforward subtraction of auxiliary length control noise  

E-Print Network [OSTI]

LIGO, the Laser Interferometer Gravitational-wave Observatory, has been designed and constructed to measure gravitational wave strain via differential arm length. The LIGO 4-km Michelson arms with Fabry-Perot cavities have auxiliary length control servos for suppressing Michelson motion of the beam-splitter and arm cavity input mirrors, which degrades interferometer sensitivity. We demonstrate how a post-facto pipeline (AMPS) improves a data sample from LIGO Science Run 6 with feedforward subtraction. Dividing data into 1024-second windows, we numerically fit filter functions representing the frequency-domain transfer functions from Michelson length channels into the gravitational-wave strain data channel for each window, then subtract the filtered Michelson channel noise (witness) from the strain channel (target). In this paper we describe the algorithm, assess achievable improvements in sensitivity to astrophysical sources, and consider relevance to future interferometry.

Grant David Meadors; Keita Kawabe; Keith Riles

2014-04-24T23:59:59.000Z

351

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

352

Property:Length (m) | Open Energy Information  

Open Energy Info (EERE)

AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page on Google Bookmark EERE: Alternative Fuels Data CenterFranconia, Virginia: Energy ResourcesLoadingPenobscot County,ContAddr2 Jump to: navigation,PVYearsDisplay/GraphicsLength (m) Jump to:

353

TREKisM At Length Issue 2  

E-Print Network [OSTI]

. "Triskelian Fledgeling" — by Vel Jaeger "Kelvan Exile" — by Vel Jaeger 111. Romulan Astronomy — by Robert S. Sayes 113c Trek-M's Speak their Minds on ST:TMP 121. A Glance Backwards - reactions to TaL I (first issue of TREKisM at Length) 122. Trivia Quizes #3...\\un Speck run. "fynjrur^run. -Storu Ipu1- 'The^dds" UYena T^fc* Ink.nc l'*- bjj rafrick La\\fena ^aq Kidd LuckICKU ©/980' -14- 0N CONVENTIONAL OCCASIONS The following Is a conglomeration of reports, Interviews, and reminiscences from TREKisM members...

Multiple Contributors

1981-01-01T23:59:59.000Z

354

TREKiSM At Length Issue 5  

E-Print Network [OSTI]

Trek IV! SHALOM PAX PEACE to us all in 1986 Table of Contents TITLE AUTHOR ARTIST PAGE I. DATA ENTRIES FROST ON THE TYPEWRITER V.L. Thorn LaVena Kay Kldd 2 "Trek Omen" V.L. Thorn 6 (originally appeared In TREKisM #26) JAMES T. KIRK vs THE COMPUTER... appeared in TREKisM at Length III) TALES FROM THE VULCAN HEARTH Karen C. Hunter 53 HOW THE VULCANS LOST THEIR WINGS 54 THE SKY GOD'S DAUGHTER 56 THE GIFT OF THE GODS LaVena Kay Kldd 57 "Sul Generis" V.L. Thorn 58 "Cat-Kin" Emily Ross 60 (originally appeared...

Multiple Contributors

1988-01-01T23:59:59.000Z

355

TrekISM At Length Issue 3  

E-Print Network [OSTI]

Length III is published by the Star Trek Special Interest Group LSIGJ of Mensa. Copyright (c) 1983..., 1701 W. Third St, Brooklyn NY 11223. \\S In January Paramount STAR TREK new produc Star Trek' no time wa two-and-a- of TREKisM interested said in an Thank you, never ceas the contin eternally ixgmqp^ion of 19 P i c t u r II. A er, Ha...

Multiple Contributors

1983-01-01T23:59:59.000Z

356

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

357

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

358

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

359

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

360

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

Note: This page contains sample records for the topic "improves fracture length" 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

Poroelastic modeling of fracture-seismic wave interaction  

SciTech Connect (OSTI)

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

Nakagawa, Seiji

2008-08-15T23:59:59.000Z

362

San Juan Fracture Characterization Project: Status and current results  

SciTech Connect (OSTI)

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

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

2001-02-26T23:59:59.000Z

363

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

364

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

365

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.

366

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

367

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

368

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

369

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

370

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

371

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.

372

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

373

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

374

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

375

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

376

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.

377

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

378

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

379

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

380

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

Note: This page contains sample records for the topic "improves fracture length" 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

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

382

Analysis of error in using fractured gas well type curves for constant pressure production  

E-Print Network [OSTI]

of normalized time and normalized cumulative production is a large improvement over using a constant evaluation pressure. 0 imens ion less cumulative production type curves are particularly useful in modeling production for economic projections, such as re... of MASTER OF SCIENCE May 1987 Major Subject: Petroleum Engineering ANALYSIS OF ERROR IN USING FRACTURED GAS WELL TYPE CURVES FOR CONSTANT PRESSURE PRDDUCTION A Thesis by DAVID WAYNE SCHKADE Approved as to style and content by: S. A. Ho lditch...

Schkade, David Wayne

1987-01-01T23:59:59.000Z

383

Effects of flaws on fracture behavior of structural ceramics  

SciTech Connect (OSTI)

We evaluated the effects of fiber coating thickness, fiber orientation, and elevated temperature on flaw morphology and mechanical properties of Nicalon-fiber-reinforced SiC matrix composites with fiber cloth lay-up sequences of 0{degree}/45{degrees}, 0{degree}/20{degrees}/60{degrees}, and 0{degree}/40{degrees}/60{degrees} and fiber coating thicknesses of 0. 2 and 0.4{mu}m. For the three fiber cloth lay-up sequences (0{degree}/45{degrees}, 0{degree}/20{degrees}/60{degrees}, and 0{degree}/40{degrees}/60{degrees}), mechanical property (first matrix cracking stress, ultimate stress, and work of fracture) initially increase with coating thickness and reach peak values at a coating thickness of 0.2{mu}m. A further increase in coating thickness does not result in further improvements in mechanical properties; this is related to the role of coatings in protecting fibers from damage during composite processing. Measured values of strength and work-of- fracture of the above composites at elevated temperatures increased with temperature up to 1200{degrees}C, but decreased at higher temperatures. This decrease is correlated to in-situ fiber strength and fiber/matrix interface degradation. Correlations between model prediction and measured room-temperature ultimate strength of composites with 0{degree}45{degrees} and 0{degree}/40{degrees}/60{degrees} lay-up sequences were established by using in-situ fiber strength characteristics. The failure modes and degradation mechanisms in hot-gas filters and ceramic composite joints are being characterized by the mechanical and fractographic evaluation techniques established thus far. Correlations of these results with those of nondestructive evaluation can provide critical information for improved quality control.

Singh, J.P.; Singh, D.; Sutaria, M.

1996-05-01T23:59:59.000Z

384

Naturally fractured tight gas reservoir detection optimization  

SciTech Connect (OSTI)

In March, work continued on characterizing probabilities for determining natural fracturing associated with the GGRB for the Upper Cretaceous tight gas plays. Structural complexity, based on potential field data and remote sensing data was completed. A resource estimate for the Frontier and Mesa Verde play was also completed. Further, work was also conducted to determine threshold economics for the play based on limited current production in the plays in the Wamsutter Ridge area. These analyses culminated in a presentation at FETC on 24 March 1999 where quantified natural fracture domains, mapped on a partition basis, which establish ''sweet spot'' probability for natural fracturing, were reviewed. That presentation is reproduced here as Appendix 1. The work plan for the quarter of January 1, 1999--March 31, 1999 comprised five tasks: (1) Evaluation of the GGRB partitions for structural complexity that can be associated with natural fractures, (2) Continued resource analysis of the balance of the partitions to determine areas with higher relative gas richness, (3) Gas field studies, (4) Threshold resource economics to determine which partitions would be the most prospective, and (5) Examination of the area around the Table Rock 4H well.

NONE

1999-04-30T23:59:59.000Z

385

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

386

Development of RWHet to Simulate Contaminant Transport in Fractured Porous Media  

SciTech Connect (OSTI)

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

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

2012-07-01T23:59:59.000Z

387

Fracture Dissolution of Carbonate Rock: An Innovative Process for Gas Storage  

SciTech Connect (OSTI)

The goal of the project is to develop and assess the feasibility and economic viability of an innovative concept that may lead to commercialization of new gas-storage capacity near major markets. The investigation involves a new approach to developing underground gas storage in carbonate rock, which is present near major markets in many areas of the United States. Because of the lack of conventional gas storage and the projected growth in demand for storage capacity, many of these areas are likely to experience shortfalls in gas deliverability. Since depleted gas reservoirs and salt formations are nearly non-existent in many areas, alternatives to conventional methods of gas storage are required. The need for improved methods of gas storage, particularly for ways to meet peak demand, is increasing. Gas-market conditions are driving the need for higher deliverability and more flexibility in injection/withdrawal cycling. In order to meet these needs, the project involves an innovative approach to developing underground storage capacity by creating caverns in carbonate rock formations by acid dissolution. The basic concept of the acid-dissolution method is to drill to depth, fracture the carbonate rock layer as needed, and then create a cavern using an aqueous acid to dissolve the carbonate rock. Assessing feasibility of the acid-dissolution method included a regional geologic investigation. Data were compiled and analyzed from carbonate formations in six states: Indiana, Ohio, Kentucky, West Virginia, Pennsylvania, and New York. To analyze the requirements for creating storage volume, the following aspects of the dissolution process were examined: weight and volume of rock to be dissolved; gas storage pressure, temperature, and volume at depth; rock solubility; and acid costs. Hydrochloric acid was determined to be the best acid to use because of low cost, high acid solubility, fast reaction rates with carbonate rock, and highly soluble products (calcium chloride) that allow for the easy removal of calcium waste from the well. Physical and chemical analysis of core samples taken from prospective geologic formations for the acid dissolution process confirmed that many of the limestone samples readily dissolved in concentrated hydrochloric acid. Further, some samples contained oily residues that may help to seal the walls of the final cavern structure. These results suggest that there exist carbonate rock formations well suited for the dissolution technology and that the presence of inert impurities had no noticeable effect on the dissolution rate for the carbonate rock. A sensitivity analysis was performed for characteristics of hydraulic fractures induced in carbonate formations to enhance the dissolution process. Multiple fracture simulations were conducted using modeling software that has a fully 3-D fracture geometry package. The simulations, which predict the distribution of fracture geometry and fracture conductivity, show that the stress difference between adjacent beds is the physical property of the formations that has the greatest influence on fracture characteristics by restricting vertical growth. The results indicate that by modifying the fracturing fluid, proppant type, or pumping rate, a fracture can be created with characteristics within a predictable range, which contributes to predicting the geometry of storage caverns created by acid dissolution of carbonate formations. A series of three-dimensional simulations of cavern formation were used to investigate three different configurations of the acid-dissolution process: (a) injection into an open borehole with production from that same borehole and no fracture; (b) injection into an open borehole with production from that same borehole, with an open fracture; and (c) injection into an open borehole connected by a fracture to an adjacent borehole from which the fluids are produced. The two-well configuration maximizes the overall mass transfer from the rock to the fluid, but it results in a complex cavern shape. Numerical simulations were performed to evalua

James W. Castle; Ronald W. Falta; David Bruce; Larry Murdoch; Scott E. Brame; Donald Brooks

2006-10-31T23:59:59.000Z

388

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

E-Print Network [OSTI]

) ............................................................................ 51 Figure B.9: Fracture Conductivity Behavior (Polymer Concentration = 50 lb/Mgal and Gas Rate = 0.5 slm) ............................................................................ 52 Figure B.10: Fracture Conductivity Behavior (Polymer... documented in API RP-61 (1989). The recommended conditions and procedure for the test includes loading a known proppant concentration (generally 2 lb/ft2) uniformly between two steel pistons at ambient temperature, maintaining closure stress for 15 minutes...

Marpaung, Fivman

2008-10-10T23:59:59.000Z

389

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

E-Print Network [OSTI]

) ............................................................................ 51 Figure B.9: Fracture Conductivity Behavior (Polymer Concentration = 50 lb/Mgal and Gas Rate = 0.5 slm) ............................................................................ 52 Figure B.10: Fracture Conductivity Behavior (Polymer... documented in API RP-61 (1989). The recommended conditions and procedure for the test includes loading a known proppant concentration (generally 2 lb/ft2) uniformly between two steel pistons at ambient temperature, maintaining closure stress for 15 minutes...

Marpaung, Fivman

2009-05-15T23:59:59.000Z

390

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

391

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

SciTech Connect (OSTI)

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

Poston, S.W.

1991-12-31T23:59:59.000Z

392

A Triple-Porosity Model for Fractured Horizontal Wells  

E-Print Network [OSTI]

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

Alahmadi, Hasan Ali H.

2010-10-12T23:59:59.000Z

393

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

394

Fracture analysis of axially cracked pressure tube of pressurized heavy water reactor  

SciTech Connect (OSTI)

Three Dimensional (313) finite element elastic plastic fracture analysis was done for through wall axially cracked thin pressure tubes of 220 MWe Indian Pressurized Heavy Water Reactor. The analysis was done for Zr-2 and Zr-2.5Nb pressure tubes operating at 300{degrees}C and subjected to 9.5 Mpa internal pressure. Critical crack length was determined based on tearing instability concept. The analysis included the effect of crack face pressure due to the leaking fluid from tube. This effect was found to be significant for pressure tubes. The available formulae for calculating J (for axially cracked tubes) do not take into account the effect of crack face pressure. 3D finite element analysis also gives insight into variation of J across the thickness of pressure tube. It was observed that J is highest at the mid-surface of tube. The results have been presented in the form of across the thickness average J value and a peak factor on J. Peak factor on J is ratio of J at mid surface to average J value. Crack opening area for different cracked lengths was calculated from finite element results. The fracture assessment of pressure tubes was also done using Central Electricity Generating Board R-6 method. Ductile tearing was considered.

Krishnan, S.; Bhasin, V.; Mahajan, S.C. [Bhabha Atomic Research Centre, Bombay (India)] [and others

1997-04-01T23:59:59.000Z

395

Smoothed Particle Magnetohydrodynamics II. Variational principles and variable smoothing length terms  

E-Print Network [OSTI]

In this paper we show how a Lagrangian variational principle can be used to derive the SPMHD (smoothed particle magnetohydrodynamics) equations for ideal MHD. We also consider the effect of a variable smoothing length in the SPH kernels after which we demonstrate by numerical tests that the consistent treatment of terms relating to the gradient of the smoothing length in the SPMHD equations significantly improves the accuracy of the algorithm. Our results complement those obtained in a companion paper (Price and Monaghan 2003a, paper I) for non ideal MHD where artificial dissipative terms were included to handle shocks.

D. J. Price; J. J. Monaghan

2003-10-28T23:59:59.000Z

396

Low-coherent WDM reflectometry for accurate fiber length monitoring  

E-Print Network [OSTI]

A fiber-optic low-coherent reflectometer was developed to accurately monitor fiber length variation. A large length-coverage range was obtained by using a fiber Bragg grating array in a wavelength-division-multiplexing ...

Hui, Rongqing; Thomas, J.; Allen, Christopher Thomas; Fu, B.; Gao, S.

2003-01-01T23:59:59.000Z

397

Dictionaries Using Variable-Length Keys and Data, with Applications *  

E-Print Network [OSTI]

(Isil- logn, 1) + Itil) and Isil is the length of bit string si. We assume a word length w > log m. We present string Isil > 1, Itil > 1 for all bit-strings si and ti. Fox' fixed-length keys the dictionary problem

Blelloch, Guy E.

398

Impact fracture behavior of HT9 duct  

SciTech Connect (OSTI)

Ferritic alloys are known to undergo a ductile-brittle transition as the test temperature is decreased. This inherent problem has limited their applications to reactor component materials subjected to low neutron exposures. However, the excellent resistance to void swelling exhibited by these alloys has led to choosing the materials as candidate materials for fast and fusion reactor applications. Despite the ductile-brittle transition problem, results show that the materials exhibit superior resistance to fracture under very high neutron fluences at irradiation temperatures above 380{degrees}C. Impact testing on FFTF duct sections of HT9 indicates that HT9 ducts have adequate fracture toughness at much higher temperatures for handling operations at room temperature and refueling operations.

Huang, F.H. [Westinghouse Hanford Co., Richland, WA (United States); Gelles, D.S. [Pacific Northwest Lab., Richland, WA (United States)

1994-07-01T23:59:59.000Z

399

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

400

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

Note: This page contains sample records for the topic "improves fracture length" 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

Compact noninvasive electron bunch-length monitor  

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

A compact rf cavity was constructed that simultaneously resonates at many harmonic modes when excited by a repetitive bunched electron beam passing through its bore. The excitation of these modes provides a Fourier description of the temporal characteristics of the bunch train. The cavity was used to noninvasively characterize electron bunches produced from thin and thick GaAs photocathodes inside a DC high voltage photogun illuminated with 37 ps (full width half maximum, FWHM) laser pulses at repetition rates near 1500 MHz, at average beam current from 5 to 500????A , and at beam energy from 75 to 195 keV. The cavity bunch-length monitor could detect electron bunches as short as 57 ps (FWHM) when connected directly to a sampling oscilloscope, and could clearly distinguish bunches with varying degrees of space-charge induced growth and with different tail signatures. Efforts are under way to detect shorter bunches by designing cavities with increased bandwidth. This demonstration lends credibility to the idea that these cavities could also be used for other applications, including bunching and shaping, when driven with external rf.

Roberts, B.; Mammei, R. R.; Poelker, M.; McCarter, J. L.

2012-12-01T23:59:59.000Z

402

Characterization of fracture networks for fluid flow analysis  

SciTech Connect (OSTI)

The analysis of fluid flow through fractured rocks is difficult because the only way to assign hydraulic parameters to fractures is to perform hydraulic tests. However, the interpretation of such tests, or ''inversion'' of the data, requires at least that we know the geometric pattern formed by the fractures. Combining a statistical approach with geophysical data may be extremely helpful in defining the fracture geometry. Cross-hole geophysics, either seismic or radar, can provide tomograms which are pixel maps of the velocity or attenuation anomalies in the rock. These anomalies are often due to fracture zones. Therefore, tomograms can be used to identify fracture zones and provide information about the structure within the fracture zones. This structural information can be used as the basis for simulating the degree of fracturing within the zones. Well tests can then be used to further refine the model. Because the fracture network is only partially connected, the resulting geometry of the flow paths may have fractal properties. We are studying the behavior of well tests under such geometry. Through understanding of this behavior, it may be possible to use inverse techniques to refine the a priori assignment of fractures and their conductances such that we obtain the best fit to a series of well test results simultaneously. The methodology described here is under development and currently being applied to several field sites. 4 refs., 14 figs.

Long, J.C.S.; Billaux, D.; Hestir, K.; Majer, E.L.; Peterson, J.; Karasaki, K.; Nihei, K.; Gentier, S.; Cox, L.

1989-06-01T23:59:59.000Z

403

Laboratory testing of cement grouting of fractures in welded tuff  

SciTech Connect (OSTI)

Fractures in the rock mass surrounding a repository and its shafts, access drifts, emplacement rooms and holes, and exploratory or in-situ testing holes, may provide preferential flowpaths for the flow of groundwater or air, potentially containing radionuclides. Such cracks may have to be sealed. The likelihood that extensive or at least local grouting will be required as part of repository sealing has been noted in numerous publications addressing high level waste repository closing. The objective of this work is to determine the effectiveness of fracture sealing (grouting) in welded tuff. Experimental work includes measurement of intact and fracture permeability under various normal stresses and injection pressures. Grout is injected into the fractures. The effectiveness of grouting is evaluated in terms of grout penetration and permeability reduction, compared prior to and after grouting. Analysis of the results include the effect of normal stress, injection pressure, fracture roughness, grout rheology, grout bonding, and the radial extent of grout penetration. Laboratory experiments have been performed on seventeen tuff cylinders with three types of fractures: (1) tension induced cracks, (2) natural fractures, and (3) sawcuts. Prior to grouting, the hydraulic conductivity of the intact rock and of the fractures is measured under a range of normal stresses. The surface topography of the fracture is mapped, and the results are used to determine aperture distributions across the fractures. 72 refs., 76 figs., 25 tabs.

Sharpe, C.J.; Daemen, J.J.

1991-03-01T23:59:59.000Z

404

Lisburne Formation fracture characterization and flow modeling  

E-Print Network [OSTI]

lead to exponential distrtbutions; multiplicatory processes as they occur in breakage lead 10 to lognormal distributions; and continuity of the process from smallest to largest sizes produces hyperbolic (fractal) distributions. However, a rigorous... of fractures on related outcrops was in the range of 1, 6-1. 8. Brock (1971) stated an important rule of thumb of fractal studies: the linearity on the double logarithmic plot should extend over at least two or three orders of naagnitude ol particle size...

Karpov, Alexandre Valerievich

2001-01-01T23:59:59.000Z

405

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

406

Effects of oxygen on fracturing fluids  

SciTech Connect (OSTI)

The stability of polysaccharide gels at high temperature is limited by such factors as pH, mechanical degradation, and oxidants. Oxygen is unavoidably placed in fracturing fluids through dissolution of air. To prevent premature degradation of the fracturing fluid by this oxidant, oxygen scavengers are commonly used. In this paper, the effects of oxygen and various oxygen scavengers on gel stability will be presented. Mechanical removal of oxygen resulted in surprisingly stable fracturing gels at 275 F. However, chemical removal of oxygen gave mixed results. Test data from sodium thiosulfate, sodium sulfite, and sodium erythorbate used as oxygen scavengers/gel stabilizers showed that the efficiency of oxygen removal from gels did not directly coincide with the viscosity retention of the gel, and large excesses of additives were necessary to provide optimum gel stabilization. The inability of some oxygen scavengers to stabilize the gel was the result of products created from the interaction of oxygen with the oxygen scavenger, which in turn, produced species that degraded the gel. The ideal oxygen scavenger should provide superior gel stabilization without creating detrimental side reaction products. Of the materials tested, sodium thiosulfate appeared to be the most beneficial.

Walker, M.L.; Shuchart, C.E.; Yaritz, J.G.; Norman, L.R.

1995-11-01T23:59:59.000Z

407

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

SciTech Connect (OSTI)

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

Faybishenko, Boris

2002-11-27T23:59:59.000Z

408

Conformance Improvement Using Gels  

SciTech Connect (OSTI)

This research project had two objectives. The first objective was to identify gel compositions and conditions that substantially reduce flow through fractures that allow direct channeling between wells, while leaving secondary fractures open so that high fluid injection and production rates can be maintained. The second objective was to optimize treatments in fractured production wells, where the gel must reduce permeability to water much more than that to oil.

Seright, Randall S.; Schrader, Richard; II Hagstrom, John; Wang, Ying; Al-Dahfeeri, Abdullah; Gary, Raven; Marin; Amaury; Lindquist, Brent

2002-09-26T23:59:59.000Z

409

HYDROGEN-ASSISTED FRACTURE IN FORGED TYPE 304L AUSTENITIC STAINLESS STEEL  

SciTech Connect (OSTI)

Austenitic stainless steels generally have good resistance to hydrogen-assisted fracture; however, structural designs for high-pressure gaseous hydrogen are constrained by the low strength of this class of material. Forging is used to increase the low strength of austenitic stainless steels, thus improving the efficiency of structural designs. Hydrogen-assisted racture, however, depends on microstructural details associated with manufacturing. In this study, hydrogen-assisted fracture of forged type 304L austenitic stainless steel is investigated. Microstructural variation in multi-step forged 304L was achieved by forging at different rates and temperatures, and by process annealing. High internal hydrogen content in forged type 304L austenitic stainless steel is achieved by thermal precharging in gaseous hydrogen and results in as much as 50% reduction of tensile ductility.

Switzner, Nathan; Neidt, Ted; Hollenbeck, John; Knutson, J.; Everhart, Wes; Hanlin, R. [University of Missouri-Kansas City] [University of Missouri-Kansas City; Bergen, R. [Precision Metal Products] [Precision Metal Products; Balch, D. K. [Sandia Natl Laboratory] [Sandia Natl Laboratory

2012-09-06T23:59:59.000Z

410

Development of an Advanced Hydraulic Fracture Mapping System  

SciTech Connect (OSTI)

The project to develop an advanced hydraulic fracture mapping system consisted of both hardware and analysis components in an effort to build, field, and analyze combined data from tiltmeter and microseismic arrays. The hardware sections of the project included: (1) the building of new tiltmeter housings with feedthroughs for use in conjunction with a microseismic array, (2) the development of a means to use separate telemetry systems for the tilt and microseismic arrays, and (3) the selection and fabrication of an accelerometer sensor system to improve signal-to-noise ratios. The analysis sections of the project included a joint inversion for analysis and interpretation of combined tiltmeter and microseismic data and improved methods for extracting slippage planes and other reservoir information from the microseisms. In addition, testing was performed at various steps in the process to assess the data quality and problems/issues that arose during various parts of the project. A prototype array was successfully tested and a full array is now being fabricated for industrial use.

Norm Warpinski; Steve Wolhart; Larry Griffin; Eric Davis

2007-01-31T23:59:59.000Z

411

Mixed-mode fracture of human cortical bone Elizabeth A. Zimmermann a,b  

E-Print Network [OSTI]

Mixed-mode fracture of human cortical bone Elizabeth A. Zimmermann a,b , Maximilien E. Launey Available online 1 July 2009 Keywords: Human cortical bone Mixed-mode fracture Fracture toughness Fracture mechanisms a b s t r a c t Although the mode I (tensile opening) fracture toughness has been the focus

Ritchie, Robert

412

Author's personal copy Calibration procedures for a computational model of ductile fracture  

E-Print Network [OSTI]

Author's personal copy Calibration procedures for a computational model of ductile fracture Z. Xue fracture Computational fracture Shear fracture Damage parameters a b s t r a c t A recent extension of the cup-cone fracture mode in the neck of a round tensile bar. Ductility of a notched round bar provides

Hutchinson, John W.

413

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

414

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

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

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

415

Hydraulic fracturing and geothermal energy development in Japan  

SciTech Connect (OSTI)

This paper is a review of research and development on geothermal energy extraction in Japan especially on hydraulic fracturing. First recent geothermal developments in Japan are outlined in Part I. An increase in the production rate of geothermal wells may be highly dependent on the geothermal well stimulation technology based on hydraulic fracturing. The hydraulic fracturing technique must be developed also for geothermal energy to be extracted from hot, dry rock masses. In Part II, the research on hydraulic fracturing and field application are reviewed.

Abe, H.; Suyama, J.; Takahashi, H.

1982-09-01T23:59:59.000Z

416

Application of the directional hydraulic fracturing at Berezovskaya Mine  

SciTech Connect (OSTI)

The paper analyzes the experimental research of the directional hydraulic fracturing applied for weakening of rocks at Berezovskaya Mine (Kuznetsk Coal Basin) in 2005-2006.

Lekontsev, Y.M.; Sazhin, P.V. [Russian Academy of Sciences, Novosibirsk (Russian Federation). Institute for Mining

2008-05-15T23:59:59.000Z

417

Reflection and transmission coefficients of a fracture in transversely ...  

E-Print Network [OSTI]

The study of the reflection-transmission problem of a fracture plays an ...... material or abrupt changes in COF (Smith, 1996; Anandakrishnan, 1996; Horgan et al.,.

2011-11-28T23:59:59.000Z

418

Determination Of The Orientation Of Open Fractures From Hydrophone VSP  

E-Print Network [OSTI]

Open fractures are of interest in many areas such as ground water contamination, hazardous waste disposal, oil and gas recovery, and geothermal energy extraction. In

Lee, Jung Mo

1995-01-01T23:59:59.000Z

419

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

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

Oil Recovery Deepwater Tech Methane Hydrate Field Demo of Eco-Friendly Propped Hydraulic Fractures 11123-23 Primary Performer DaniMer Scientific, LLC (Bainbridge, GA)...

420

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...

Note: This page contains sample records for the topic "improves fracture length" 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

Finding Large Aperture Fractures in Geothermal Resource Areas...  

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

3-D mapping of Large Aperture Fractures (LAF's) * Budget: 679,000 - Phase 2: Drilling - January-December, 2011. * Task 4: Stepout drilling from existing production wells....

422

Studies of Transport Properties of Fractures: Final Report  

SciTech Connect (OSTI)

We proposed to study several key factors controlling the character and evolution of fracture system permeability and transport processes. We suggest that due to surface roughness and the consequent channeling in single fractures and in fracture intersections, the tendency of a fracture system to plug up, remain permeable, or for permeability to increase due to chemical dissolution/precipitation conditions will depend strongly on the instantaneous flow channel geometry. This geometry will change as chemical interaction occurs, thus changing the permeability through time. To test this hypothesis and advance further understanding toward a predictive capability, we endeavored to physically model and analyze several configurations of flow and transport of inert and chemically active fluids through channels in single fractures and through fracture intersections. This was an integrated program utilizing quantitative observations of fractures and veins in drill core, quantitative and visual observations of flow and chemical dissolution and precipitation within replicas of real rough-walled fractures and fracture intersections, and numerical modeling via lattice Boltzmann methods.

Stephen R. Brown

2006-06-30T23:59:59.000Z

423

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

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

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

424

AN APPROACH TO THE FRACTURE HYDROLOGY AT STRIPA: PRELIMINARY RESULTS  

E-Print Network [OSTI]

Geochemistry and Isotope Hydrology of Groundwaters in theAN APPROACH TO THE FRACTURE HYDROLOGY AT STRIPA: PRELIMINARYGeochemistry and Isotope Hydrology of Groundwaters in the

Gale, J.E.

2010-01-01T23:59:59.000Z

425

Characterization Of Fracture Patterns In The Geysers Geothermal...  

Open Energy Info (EERE)

navigation, search OpenEI Reference LibraryAdd to library Report: Characterization Of Fracture Patterns In The Geysers Geothermal Reservoir By Shear-Wave Splitting Abstract The...

426

Characterization of subsurface fracture patterns in the Coso...  

Open Energy Info (EERE)

LibraryAdd to library Conference Proceedings: Characterization of subsurface fracture patterns in the Coso geothermal reservoir by analyzing shear-wave splitting of...

427

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

Open Energy Info (EERE)

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

428

Detection and Characterization of Natural and Induced Fractures...  

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

Institute of Technology) Objectives: To combine geophysical methods for reservoir and fracture characterization with rock physics measurements made under in-situ conditions (up to...

429

Fracture Evolution Following a Hydraulic Stimulation within an...  

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

Fracture Evolution Following a Hydraulic Stimulation within an EGS Reservoir Principal Investigator Peter Rose Energy and Geoscience Institute at the University of Utah Project...

430

Evaluation of subsurface fracture geometry using fluid pressure...  

Open Energy Info (EERE)

subsurface fracture geometry using fluid pressure response to solid earth tidal strain Jump to: navigation, search OpenEI Reference LibraryAdd to library Report: Evaluation of...

431

Detection and Characterization of Natural and Induced Fractures...  

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

Geothermal Systems Project objectives: Combine geophysical methods for reservoir and fracture characterization with rock physics measurements made under in-situ conditions (up to...

432

Detection and Characterization of Natural and Induced Fractures...  

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

RelevanceImpact of Research - Combine geophysical methods for reservoir and fracture characterization with rock physics measurements made under in-situ conditions (up to...

433

Tracer Methods for Characterizing Fracture Stimulation in Enhanced...  

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

Tracer Methods for Characterizing Fracture Stimulation in Enhanced Geothermal Systems (EGS); 2010 Geothermal Technology Program Peer Review Report Tracer Methods for Characterizing...

434

Fracture Characterization in Enhanced Geothermal Systems by Wellbore...  

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

5 4.6.4 Fracture Characterization in Enhanced Geothermal Systems by Wellbore and Reservoir Analysis Presentation Number: 031 Investigator: Horne, Roland (Stanford University)...

435

Tracer Methods for Characterizing Fracture Stimulation in Enhanced...  

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

80 4.6.7 Tracer Methods for Characterizing Fracture Stimulation in Enhanced Geothermal Systems (EGS) Presentation Number: 034 Investigator: Pruess, Karsten (Lawrence Berkeley...

436

Transitions from Oscillatory to Smooth Fracture Propagation in...  

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

Transitions from Oscillatory to Smooth Fracture Propagation in Viscoelastic Materials Jan 29 2015 10:30 AM - 11:30 AM Yehuda Braiman, Division Staff Computer Science and...

437

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) Karsten Pruess Lawrence Berkeley National Lab. May 19, 2010 This presentation does not...

438

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 Michael Batzle, PI Colorado School of Mines Track Name: Fluid...

439

Microseismicity, stress, and fracture in the Coso geothermal...  

Open Energy Info (EERE)

Microseismicity, stress, and fracture in the Coso geothermal field, California Jump to: navigation, search OpenEI Reference LibraryAdd to library Journal Article: Microseismicity,...

440

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 Principal Investigator: Philip E. Wannamaker University of Utah...

Note: This page contains sample records for the topic "improves fracture length" 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

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

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

1 4.6.1 Three-dimensional Modeling of Fracture Clusters in Geothermal Reservoirs Presentation Number: 028 Investigator: Ghassemi, Ahmad (Texas A&M University) Objectives: To...

442

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 Principal Investigator (Joseph Moore) Presenter Name (John McLennan)...

443

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

Open Energy Info (EERE)

Study Of Fracture Patterns And Densities In The Geysers Geothermal Reservoir Using Microearthquake Shear-Wave Splitting Tomography Jump to: navigation, search OpenEI Reference...

444

Dispersed Fluid Flow in Fractured Reservoirs- an Analysis of...  

Open Energy Info (EERE)

correlations. Downhole measurements of the tracer response exiting from discrete fracture zones permit further characterization of reservoir fluid flow behavior. Tracer...

445

Detection and Characterization of Natural and Induced Fractures...  

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

Geothermal Technology Program Peer Review Report Tracer Methods for Characterizing Fracture Stimulation in Enhanced Geothermal Systems (EGS); 2010 Geothermal Technology Program...

446

apophyseal ring fractures: Topics by E-print Network  

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

system 4 2 Ring solutions Kolokolnikov, Theodore 90 Self-potential observations during hydraulic fracturing University of California eScholarship Repository Summary: hydraulic...

447

Poroelastic modeling of fracture-seismic wave interaction  

E-Print Network [OSTI]

JCRM All rights reserved. Volume x, Number x, Month 200x, pp.x-x. [Issue paper]. Poroelastic modeling of fracture-seismic wave interaction. Seiji NAKAGAWA.

Toru Takahashi

2009-01-07T23:59:59.000Z

448

Advanced Hydraulic Fracturing Technology for Unconventional Tight Gas Reservoirs  

SciTech Connect (OSTI)

The objectives of this project are to develop and test new techniques for creating extensive, conductive hydraulic fractures in unconventional tight gas reservoirs by statistically assessing the productivity achieved in hundreds of field treatments with a variety of current fracturing practices ranging from 'water fracs' to conventional gel fracture treatments; by laboratory measurements of the conductivity created with high rate proppant fracturing using an entirely new conductivity test - the 'dynamic fracture conductivity test'; and by developing design models to implement the optimal fracture treatments determined from the field assessment and the laboratory measurements. One of the tasks of this project is to create an 'advisor' or expert system for completion, production and stimulation of tight gas reservoirs. A central part of this study is an extensive survey of the productivity of hundreds of tight gas wells that have been hydraulically fractured. We have been doing an extensive literature search of the SPE eLibrary, DOE, Gas Technology Institute (GTI), Bureau of Economic Geology and IHS Energy, for publicly available technical reports about procedures of drilling, completion and production of the tight gas wells. We have downloaded numerous papers and read and summarized the information to build a database that will contain field treatment data, organized by geographic location, and hydraulic fracture treatment design data, organized by the treatment type. We have conducted experimental study on 'dynamic fracture conductivity' created when proppant slurries are pumped into hydraulic fractures in tight gas sands. Unlike conventional fracture conductivity tests in which proppant is loaded into the fracture artificially; we pump proppant/frac fluid slurries into a fracture cell, dynamically placing the proppant just as it occurs in the field. From such tests, we expect to gain new insights into some of the critical issues in tight gas fracturing, in particular the roles of gel damage, polymer loading (water-frac versus gel frac), and proppant concentration on the created fracture conductivity. To achieve this objective, we have designed the experimental apparatus to conduct the dynamic fracture conductivity tests. The experimental apparatus has been built and some preliminary tests have been conducted to test the apparatus.

Stephen Holditch; A. Daniel Hill; D. Zhu

2007-06-19T23:59:59.000Z

449

Finite-element harmonic experiments to model fractured induced ...  

E-Print Network [OSTI]

Mar 10, 2014 ... Fractured hydrocarbon reservoirs have been the subject of interest in ...... size. Once a continuous fractal distribution of brine is obtained over ...

santos

450

Hydraulic Fractures: multiscale phenomena, asymptotic and numerical solutions  

E-Print Network [OSTI]

well stimulation Fracturing Fluid Proppant #12;5 Quarries #12;6 Magma flow Tarkastad #12;7 Model EQ 1

Peirce, Anthony

451

SciTech Connect: CRACK TIP PLASTICITY AND FRACTURE INITIATION...  

Office of Scientific and Technical Information (OSTI)

N50000* --Metals, Ceramics, & Other Materials; CRACKS; FRACTURE PROPERTIES; METALS BUILDING MATERIALSfracture of metal, crack tip plasticity and initiation criteria for;...

452

INJECTION AND THERMAL BREAKTHROUGH IN FRACTURED GEOTHERMAL RESERVOIRS  

E-Print Network [OSTI]

and Pruess, K. , Analysis of injection testing of geothermalreservoirs: Geothermal Resoures Council, Vol. 4. , (into a fractured geothermal reservoir: Transactions, Vol. 4,

Bodvarsson, Gudmundur S.

2012-01-01T23:59:59.000Z

453

Effective velocities in fractured media: a numerical study using the ...  

E-Print Network [OSTI]

and precise numerical study of effective velocities in fractured structures. ... In this paper, we ..... A final result is that our numerical simulations of P-, SV- and.

2002-03-18T23:59:59.000Z

454

Development of a Neutron Diffraction Based Experiemental Capability for Investigating Hydraulic Fracturing for EGS-like Conditions  

SciTech Connect (OSTI)

Hydraulic fracturing to enhance formation permeability is an established practice in the Oil & Gas (O&G) industry and is expected to be an enabler for EGS. However, it is rarely employed in conventional geothermal systems and there are significant questions regarding the translation of practice from O&G to both conventional geothermal and EGS applications. Lithological differences(sedimentary versus crystalline rocks, significantly greater formation temperatures and different desired fracture characteristics are among a number of factors that are likely to result in a gap of understanding of how to manage hydraulic fracturing practice for geothermal. Whereas the O&G community has had both the capital and the opportunity to develop its understanding of hydraulic fracturing operations empirically in the field as well through extensive R&D efforts, field testing opportunities for EGS are likely to be minimal due to the high expense of hydraulic fracturing field trials. A significant portion of the knowledge needed to guide the management of geothermal/EGS hydraulic fracturing operations will therefore likely have to come from experimental efforts and simulation. This paper describes ongoing efforts at Oak Ridge National Laboratory (ORNL) to develop an experimental capability to map the internal stresses/strains in core samples subjected to triaxial stress states and temperatures representative of EGS-like conditions using neutron diffraction based strain mapping techniques. This capability is being developed at ORNL\\'s Spallation Neutron Source, the world\\'s most powerful pulsed neutron source and is still in a proof of concept phase. A specialized pressure cell has been developed that permits independent radial and axial fluid pressurization of core samples, with axial flow through capability and a temperature rating up to 300 degrees C. This cell will ultimately be used to hydraulically pressurize EGS-representative core samples to conditions of imminent fracture and map the associated internal strain states of the sample. This will hopefully enable a more precise mapping of the rock material failure envelope, facilitate a more refined understanding of the mechanism of hydraulically induced rock fracture, particularly in crystalline rocks, and serve as a platform for validating and improving fracture simulation codes. The elements of the research program and preliminary strain mapping results of a Sierra White granite sample subjected only to compressive loading will be discussed in this paper.

Polsky, Yarom [ORNL] [ORNL; Anovitz, Lawrence {Larry} M [ORNL; An, Ke [ORNL] [ORNL; Carmichael, Justin R [ORNL] [ORNL; Bingham, Philip R [ORNL] [ORNL; Dessieux Jr, Luc Lucius [ORNL] [ORNL

2013-01-01T23:59:59.000Z

455

Variational fracture mechanics The fracture pattern in stressed bodies is defined through the minimization of a two-field pseudo-spatial-  

E-Print Network [OSTI]

Variational fracture mechanics The fracture pattern in stressed bodies is defined through-deviatoric and masonry-like fractures. Remarkably, this latter formulation rigorously avoid material overlapping., Francfort, G. A. and J. J. Marigo, Numerical experiments in revisited brittle fracture. J. Mech. Phys

Segatti, Antonio

456

Evaluation of acid fracturing based on the "acid fracture number" concept  

E-Print Network [OSTI]

Acid fracturing is one of the preferred methods to stimulate wells in carbonate reservoirs. It consists of injecting an acid solution at high enough pressure to break down the formation and to propagate a two-wing crack away from the wellbore...

Alghamdi, Abdulwahab

2006-08-16T23:59:59.000Z

457

Interpretation of pre- and post-fracturing well tests in a geothermal reservoir  

SciTech Connect (OSTI)

Pre- and post-fracturing well tests in TG-2 well drilled next to the Matsukawa field are interpreted for evaluating effects of a massive hydraulic fracturing treatment. The interpreted data include multiple-step rate tests, a two-step rate test, and falloff tests. Pressure behaviors of massive hydraulic fracturing are matched by a simulator of dynamic fracture option. Fracture parting pressures can be evaluated from the multiple-step rate test data. The multiple-step rates during the massive hydraulic fracturing treatment show that multiple fractures have been induced in sequence. Although the pre-fracturing falloff tests are too short, fracture propagation can be evaluated qualitatively from the falloff data. Interpretation of the falloff test immediately after the MHF suggests that extensive fractures have been created by the MHF, which is verified by simulation. The post-fracturing falloff tests show that the fractures created by the MHF have closed to a great degree.

Arihara, Norio; Fukagawa, Hiroshi; Hyodo, Masami; Abbaszadeh, Maghsood

1995-01-26T23:59:59.000Z

458

Three-dimensional Modeling of Acid Transport and Etching in a Fracture  

E-Print Network [OSTI]

Acid fracture stimulation generates higher well production but requires engineering design for treatment optimization. To quantify the cost and benefit of a particular acid fracture treatment an engineer must predict the resulting fracture...

Oeth, Cassandra V

2013-11-25T23:59:59.000Z

459

On the fracture toughness of ferroelectric ceramics with electric field applied parallel to the crack front  

E-Print Network [OSTI]

On the fracture toughness of ferroelectric ceramics with electric field applied parallel crack growth. The effects of electric field on the fracture toughness of both initially unpoled and poled materials are investigated. Results for the predicted fracture toughness, remanent strain

460

COMPARING FRACTURE PROPAGATION TESTS AND RELATING TEST RESULTS TO SNOWPACK CHARACTERISTICS  

E-Print Network [OSTI]

COMPARING FRACTURE PROPAGATION TESTS AND RELATING TEST RESULTS TO SNOWPACK CHARACTERISTICS Cameron for a slab and weak layer combination to propagate a fracture. University of Calgary researchers performed propensity. KEYWORDS: fracture propagation, snowpack stability test, extended column test, propagation saw

Jamieson, Bruce

Note: This page contains sample records for the topic "improves fracture length" 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

On the fracture of human dentin: Is it stress- or strain-controlled?  

E-Print Network [OSTI]

N, Ruse ND. NTP specimen fracture toughness test applied toRO. On the in vitro fracture toughness of human dentin. Jtensile stress and fracture toughness in mild steel. J Mech

Nalla, R.K.; Kinney, J.H.; Ritchie, R.O.

2006-01-01T23:59:59.000Z

462

E-Print Network 3.0 - acute rib fracture Sample Search Results  

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

rib fracture Search Powered by Explorit Topic List Advanced Search Sample search results for: acute rib fracture Page: << < 1 2 3 4 5 > >> 1 Dynamic fracture of granular material...

463

A PURELY NUMERICAL APPROACH FOR ANALYZING FLOW TO A WELL INTERCEPTING A VERTICAL FRACTURE  

E-Print Network [OSTI]

W.R. Effect of vertical fracture on reservoir behavior --of deep, penetrating fractures in the wattenberg Field.flow through a single fracture. PhD Dissertation, Department

Narasimhan, T.N.

2011-01-01T23:59:59.000Z

464

FRACTURE MAPPING IN THE VENTILATION DRIFT AT STRIPA: PROCEDURES AND RESULTS  

E-Print Network [OSTI]

Future Work . RESULTS OF FRACTURE MAPPING AND USE OF DATAFILES. 2.1 Fracture Maps . . . • . . . . . • . . 2.2 Mapping12). 15. An Approach to the Fracture Hydrology at Stripa:

Rouleau, A.

2010-01-01T23:59:59.000Z

465

VALIDITY OF CUBIC LAW FOR FLUID FLOW IN A DEFORMABLE ROCK FRACTURE  

E-Print Network [OSTI]

hydraulic properties of fractures." T^ be published in Water14). 15. An Approach to the Fracture Hydrology at Stripa:Hydraulic Properties of Fractures by P. A. Witherspoon, C.

Witherspoon, P.A.

2010-01-01T23:59:59.000Z

466

Fracture Dislocation C6 to C7: Importance of Adequate Radiolographs  

E-Print Network [OSTI]

soma as well as a fracture dislocation with involvement ofof closed, indirect fractures and dislocations of the lower1–27. 2. Bohlman HH. Acute fractures and dislocations of the

Muñoz-Mahamud, Ernesto; Combalia, Andrés

2011-01-01T23:59:59.000Z

467

Hydraulic Fracture Optimization with a Pseudo-3D Model in Multi-layered Lithology  

E-Print Network [OSTI]

Hydraulic Fracturing is a technique to accelerate production and enhance ultimate recovery of oil and gas while fracture geometry is an important aspect in hydraulic fracturing design and optimization. Systematic design procedures are available...

Yang, Mei

2011-10-21T23:59:59.000Z

468

Imaging Hydraulic Fractures: Source Location Uncertainty Analysis At The UPRC Carthage Test Site  

E-Print Network [OSTI]

Hydraulic fracturing is a useful tool for enhancing gas and oil production. High-resolution seismic imaging of the fracture geometry and fracture growth process is the key in determining optimal spacing and location of ...

Li, Yingping

1996-01-01T23:59:59.000Z

469

Degradation of Guar-Based Fracturing Gels: A Study of Oxidative and Enzymatic Breakers  

E-Print Network [OSTI]

Unbroken gel and residue from guar-based fracturing gels can be a cause for formation damage. The effectiveness of a fracturing treatment depends on better achieveing desired fracture geometry, proper proppant placement and after that, a good clean...

Sarwar, Muhammad Usman

2012-02-14T23:59:59.000Z

470

Intrinsic Route to Melt Fracture in Polymer Extrusion: AWeakly Nonlinear Subcritical Instability of Viscoelastic Poiseuille Flow  

E-Print Network [OSTI]

Intrinsic Route to Melt Fracture in Polymer Extrusion: AWeakly Nonlinear Subcritical Instability generic route to melt fracture via a weakly nonlinear subcritical instability of viscoelastic Poiseuille ``subcritical'') instability due to normal stress effects; this instability appears to make melt fracture

van Saarloos, Wim

471

Naturally fractured tight gas reservoir detection optimization  

SciTech Connect (OSTI)

The work plan for October 1, 1997 to September 30, 1998 consisted of investigation of a number of topical areas. These topical areas were reported in four quarterly status reports, which were submitted to DOE earlier. These topical areas are reviewed in this volume. The topical areas covered during the year were: (1) Development of preliminary tests of a production method for determining areas of natural fracturing. Advanced Resources has demonstrated that such a relationship exists in the southern Piceance basin tight gas play. Natural fracture clusters are genetically related to stress concentrations (also called stress perturbations) associated with local deformation such a faulting. The mechanical explanation of this phenomenon is that deformation generally initiates at regions where the local stress field is elevated beyond the regional. (2) Regional structural and geologic analysis of the Greater Green River Basin (GGRB). Application of techniques developed and demonstrated during earlier phases of the project for sweet-spot delineation were demonstrated in a relatively new and underexplored play: tight gas from continuous-typeUpper Cretaceous reservoirs of the Greater Green River Basin (GGRB). The effort included data acquisition/processing, base map generation, geophysical and remote sensing analysis and the integration of these data and analyses. (3) Examination of the Table Rock field area in the northern Washakie Basin of the Greater Green River Basin. This effort was performed in support of Union Pacific Resources- and DOE-planned horizontal drilling efforts. The effort comprised acquisition of necessary seismic data and depth-conversion, mapping of major fault geometry, and analysis of displacement vectors, and the development of the natural fracture prediction. (4) Greater Green River Basin Partitioning. Building on fundamental fracture characterization work and prior work performed under this contract, namely structural analysis using satellite and potential field data, the GGRB was divided into partitions that will be used to analyze the resource potential of the Frontier and Mesaverde Upper Cretaceous tight gas play. A total of 20 partitions were developed, which will be instrumental for examining the Upper Cretaceous play potential. (5) Partition Analysis. Resource assessment associated with individual partitions was initiated starting with the Vermilion Sub-basin and the Green River Deep (which include the Stratos well) partitions (see Chapter 5). (6) Technology Transfer. Tech transfer was achieved by documenting our research and presenting it at various conferences.

NONE

1998-11-30T23:59:59.000Z

472

Turbulent flow of gas in fractures  

E-Print Network [OSTI]

sises of 40 - 60, 20 - 40 and 10 - 20 mesh and with varying concentration of proppants . The confining pressure was varied for each core up to $, 000 psi step by step. The proppant concentration in each fracture was varied up to a complete monolayer... an ovex'bux'den pressure of 4, 000 psi, the reduction in flow capaoity would vary from 86 $ to 76 4 with corresponding change of pressure dxop from 2, 000 psi to 7, 000 psi across a 320 ft long fractuxe. ACKHOWLEDGENEN% The author wishes to extend...

Koh, Wong In

1974-01-01T23:59:59.000Z

473

Fracture Characterization Technologies | Open Energy Information  

Open Energy Info (EERE)

AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page on Google Bookmark EERE: Alternative Fuels Data Center Home5b9fcbce19 NoPublicIDAPowerPlantSitingConstruction.pdfNotify98.pdf JumpFlixMapFileFostoria,Chapel,Foyil, Oklahoma:Fracture

474

SQUID magnetometry from nanometer to centimeter length scales  

E-Print Network [OSTI]

length scales . . . . . . . Josephson Junction and SQUIDin nanoscale weak link josephson junction oscillators. Phys.cation by unbiased Josephson junctions. Journ. Appl. Phys. ,

Hatridge, Michael Jonathan

2010-01-01T23:59:59.000Z

475

Structuring Materials on Multiple Length Scales for Energy Application...  

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

Structuring Materials on Multiple Length Scales for Energy Applications October 25, 2012 at 3pm36-428 Adreas Stein Department of Chemistry, University of Minnesota astein...

476

Page 1 of 5 Narrative Description of Hydraulic Fracturing Draft Regulations  

E-Print Network [OSTI]

Page 1 of 5 Narrative Description of Hydraulic Fracturing Draft Regulations The Department of Conservation has released a discussion draft of hydraulic fracturing (HF) regulations. This narrative attempts

477

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

478

E-Print Network 3.0 - applying fracture mechanics Sample Search...  

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

fracture mechanics Search Powered by Explorit Topic List Advanced Search Sample search results for: applying fracture mechanics Page: << < 1 2 3 4 5 > >> 1 Geophysical Research...

479

E-Print Network 3.0 - acetabular fracture fixation Sample Search...  

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

fracture fixation Search Powered by Explorit Topic List Advanced Search Sample search results for: acetabular fracture fixation Page: << < 1 2 3 4 5 > >> 1 252 IEEE TRANSACTIONS ON...

480

E-Print Network 3.0 - age fracture mechanics Sample Search Results  

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

fracture mechanics Search Powered by Explorit Topic List Advanced Search Sample search results for: age fracture mechanics Page: << < 1 2 3 4 5 > >> 1 1. RESERVOIR CHARACTERIZATION...

Note: This page contains sample records for the topic "improves fracture length" 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

E-Print Network 3.0 - arch fracture intraoperatively Sample Search...  

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

fracture intraoperatively Search Powered by Explorit Topic List Advanced Search Sample search results for: arch fracture intraoperatively Page: << < 1 2 3 4 5 > >> 1 Biomedical...

482

E-Print Network 3.0 - acetabular internal fracture Sample Search...  

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

internal fracture Search Powered by Explorit Topic List Advanced Search Sample search results for: acetabular internal fracture Page: << < 1 2 3 4 5 > >> 1 Hip-Preserving Surgery:...

483

E-Print Network 3.0 - arrest fracture toughness Sample Search...  

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

fracture toughness Search Powered by Explorit Topic List Advanced Search Sample search results for: arrest fracture toughness Page: << < 1 2 3 4 5 > >> 1 ON THE SUSTAINABILITY AND...

484

E-Print Network 3.0 - asymmetric hydraulic fracture Sample Search...  

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

hydraulic fracture Search Powered by Explorit Topic List Advanced Search Sample search results for: asymmetric hydraulic fracture Page: << < 1 2 3 4 5 > >> 1 Self-potential...

485

E-Print Network 3.0 - active fracture model Sample Search Results  

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

fracture model Search Powered by Explorit Topic List Advanced Search Sample search results for: active fracture model Page: << < 1 2 3 4 5 > >> 1 THELEADINGEDGESeptember2007Vol.26,...

486

E-Print Network 3.0 - acute compression fracture Sample Search...  

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

compression fracture Search Powered by Explorit Topic List Advanced Search Sample search results for: acute compression fracture Page: << < 1 2 3 4 5 > >> 1 1. RESERVOIR...

487

E-Print Network 3.0 - accelerates fracture healing Sample Search...  

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

fracture healing Search Powered by Explorit Topic List Advanced Search Sample search results for: accelerates fracture healing Page: << < 1 2 3 4 5 > >> 1 Self-healing structural...

488

E-Print Network 3.0 - alloys fracture mechanics Sample Search...  

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

fracture mechanics Search Powered by Explorit Topic List Advanced Search Sample search results for: alloys fracture mechanics Page: << < 1 2 3 4 5 > >> 1 International Journal of...

489

E-Print Network 3.0 - anisotropic fracture behavior Sample Search...  

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

fracture behavior Search Powered by Explorit Topic List Advanced Search Sample search results for: anisotropic fracture behavior Page: << < 1 2 3 4 5 > >> 1 Characterization of...

490

E-Print Network 3.0 - apparent interfacial fracture Sample Search...  

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

interfacial fracture Search Powered by Explorit Topic List Advanced Search Sample search results for: apparent interfacial fracture Page: << < 1 2 3 4 5 > >> 1 Int J Fract (2007)...

491

E-Print Network 3.0 - advanced fracture characterization Sample...  

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

fracture characterization Search Powered by Explorit Topic List Advanced Search Sample search results for: advanced fracture characterization Page: << < 1 2 3 4 5 > >> 1 Analysis...

492

E-Print Network 3.0 - assisted coronoid fracture Sample Search...  

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coronoid fracture Search Powered by Explorit Topic List Advanced Search Sample search results for: assisted coronoid fracture Page: << < 1 2 3 4 5 > >> 1 COMPUTER-AIDED PLANNING...

493

E-Print Network 3.0 - atomistic fracture mechanics Sample Search...  

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

fracture mechanics Search Powered by Explorit Topic List Advanced Search Sample search results for: atomistic fracture mechanics Page: << < 1 2 3 4 5 > >> 1 Plenary Lecture...

494

Surfactant-enhanced spontaneous imbibition process in highly fractured carbonate reservoirs.  

E-Print Network [OSTI]

??Highly fractured carbonate reservoirs are a class of reservoirs characterized by high conductivity fractures surrounding low permeability matrix blocks. In these reservoirs, wettability alteration is… (more)

Chen, Peila

2011-01-01T23:59:59.000Z

495

Mobility control of chemical EOR fluids using foam in highly fractured reservoirs.  

E-Print Network [OSTI]

??Highly fractured and vuggy oil reservoirs represent a challenge for enhanced oil recovery (EOR) methods. The fractured networks provide flow paths several orders of magnitude… (more)

Gonzale?z Llama, Oscar

2011-01-01T23:59:59.000Z

496

Impact fracture behavior of model system modified polypropylene  

E-Print Network [OSTI]

-edge-notched three-point-bend tests were performed to obtain the values of fracture toughness. A correlation exists between the Izod impact values and the size of the damage zone after fracture. Damage analysis using the double-notch four-point-bend Charpy impact...

Estrada, Albert Jesse

2000-01-01T23:59:59.000Z

497

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 in aquifers overlying the Marcellus formation but asserts that we prematurely ascribed its cause to hydraulic mechanisms were leaky gas well casings and the possibility that hydraulic fracturing might generate new

Jackson, Robert B.

498

Elastic properties of saturated porous rocks with aligned fractures  

E-Print Network [OSTI]

Several treatments of the porous media with aligned fractures have been ...... a function of background porosity /p for water-satu- rated rock (Kf = 2.25 ? 109 Pa). .... that are in hydraulic equilibrium with the fractures, the fluid will squeeze from ...

2003-12-02T23:59:59.000Z

499

Real Time Dynamic Fracture with Volumetric Approximate Convex Decompositions  

E-Print Network [OSTI]

¨uller Nuttapong Chentanez Tae-Yong Kim NVIDIA Figure 1: Destruction of a Roman arena with 1m vertices and 500k and complex objects in real time. The common method for fracture simulation in computer games is to pre-fracture models and replace objects by their pre-computed parts at run-time. This popular method

Müller-Fischer, Matthias

500

SEISMIC INVESTIGATION OF WRENCH FAULTING AND FRACTURING AT RULISON  

E-Print Network [OSTI]

to gas production at Rulison. Fracture zones are associated with fault trends and areas of deformation networks that help determine gas migration and accumulation. This thesis presents the characterization of the complex wrench fault network at Rulison Field, and its linkage to enhanced natural fracture zones. Rulison