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1

Naturally fractured tight gas reservoir detection optimization  

SciTech Connect

Research continued on methods to detect naturally fractured tight gas reservoirs. This report discusses 3D-3C seismic acquisition and 3D P-wave alternate processing.

NONE

1995-12-31T23:59:59.000Z

2

Naturally fractured tight gas reservoir detection optimization  

SciTech Connect

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

3

Naturally fractured tight gas reservoir detection optimization  

SciTech Connect

The goal of the work this quarter has been to partition and high-grade the Greater Green River basin for exploration efforts in the Upper Cretaceous tight gas play and to initiate resource assessment of the basin. The work plan for the quarter of July 1-September 30, 1998 comprised three tasks: (1) Refining the exploration process for deep, naturally fractured gas reservoirs; (2) Partitioning of the basin based on structure and areas of overpressure; (3) Examination of the Kinney and Canyon Creek fields with respect to the Cretaceous tight gas play and initiation of the resource assessment of the Vermilion sub-basin partition (which contains these two fields); and (4) Initiation analysis of the Deep Green River Partition with respect to the Stratos well and assessment of the resource in the partition.

NONE

1998-11-30T23:59:59.000Z

4

Fracture detection, mapping, and analysis of naturally fractured gas reservoirs using seismic technology. Final report, November 1995  

SciTech Connect

Many basins in the Rocky Mountains contain naturally fractured gas reservoirs. Production from these reservoirs is controlled primarily by the shape, orientation and concentration of the natural fractures. The detection of gas filled fractures prior to drilling can, therefore, greatly benefit the field development of the reservoirs. The objective of this project was to test and verify specific seismic methods to detect and characterize fractures in a naturally fractured reservoir. The Upper Green River tight gas reservoir in the Uinta Basin, Northeast Utah was chosen for the project as a suitable reservoir to test the seismic technologies. Knowledge of the structural and stratigraphic geologic setting, the fracture azimuths, and estimates of the local in-situ stress field, were used to guide the acquisition and processing of approximately ten miles of nine-component seismic reflection data and a nine-component Vertical Seismic Profile (VSP). Three sources (compressional P-wave, inline shear S-wave, and cross-line, shear S-wave) were each recorded by 3-component (3C) geophones, to yield a nine-component data set. Evidence of fractures from cores, borehole image logs, outcrop studies, and production data, were integrated with the geophysical data to develop an understanding of how the seismic data relate to the fracture network, individual well production, and ultimately the preferred flow direction in the reservoir. The multi-disciplinary approach employed in this project is viewed as essential to the overall reservoir characterization, due to the interdependency of the above factors.

NONE

1995-10-01T23:59:59.000Z

5

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

SciTech Connect

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

NONE

1997-12-31T23:59:59.000Z

6

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

Science Conference Proceedings (OSTI)

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

NONE

1994-10-01T23:59:59.000Z

7

Fracture detection and mapping  

DOE Green Energy (OSTI)

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

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

1986-03-01T23:59:59.000Z

8

Numerical Investigation of Interaction Between Hydraulic Fractures and Natural Fractures  

E-Print Network (OSTI)

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

Xue, Wenxu

2010-12-01T23:59:59.000Z

9

Studies of injection into naturally fractured reservoirs  

DOE Green Energy (OSTI)

A semi-analytical model for studies of cold water injection into naturally fractured reservoirs has been developed. The model can be used to design the flow rates and location of injection wells in such systems. The results obtained using the model show that initially the cold water will move very rapidly through the fracture system away from the well. Later on, conductive heat transfer from the rock matrix blocks will retard the advancement of the cold water front, and eventually uniform energy sweep conditions will prevail. Where uniform energy sweep conditions are reached the cold waer movement away from the injection well will be identical to that in a porous medium; consequently maximum energy recovery from the rock matrix will be attained. The time of uniform energy sweep and the radial distance from the injection well where it occurs are greatly dependent upon the fracture spacing, but independent of the fracture aperture.

Boedvarsson, G.S.; Lai, C.H.

1982-10-01T23:59:59.000Z

10

Pressure transient analysis for naturally fractured reservoirs  

Science Conference Proceedings (OSTI)

New ideas are presented for the interpretation of pressure transient tests for wells in naturally fractured reservoirs. This work is based on the transient matrix flow model formulated by de Swaan. The differences between this model and the Warren and Root model occur during the transition flow period. It is demonstrated that the behavior of a naturally fractured reservoir can be correlated by using three dimensionless parameters. It is established that regardless of matrix geometry the transition period might exhibit a straight line whose slope is equal to half the slope of the classical parallel semilog straight lines, provided the transient matrix linear flow is present. In addition, information is provided on the estimation of fracture area per unit matrix volume or matrix parameters from the transition period semilog straight line. It is shown that matrix geometry might be identified when pressure data are smooth. Field examples are included to illustrate the application and the validity of the theoretical results of this study.

Cinco-ley, H.; Samaniego, F.V.

1982-09-01T23:59:59.000Z

11

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

12

Predicting the occurrence of open natural fractures in shale reservoirs  

SciTech Connect

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

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

1996-01-01T23:59:59.000Z

13

Three Models for Waterflooding in a Naturally Fractured Petroleum Reservoir  

E-Print Network (OSTI)

Introduction. For the purposes of this paper a naturally fractured reservoir is a porous medium that has been fractured in a regular geometric fashion; the resulting medium consists of a collection of porous matrix blocks, each of which is quite small with respect to the size of the reservoir, essentially lling out the reservoir, and a set of thin fractures that separate the blocks. The fractures will be considered to be generated by either two or three families of parallel planes. Though the total volume in the fractures is very small in comparison to the total void volume in the porous blocks, the ow of uids in such a fractured reservoir is seriously aected by the existence of the fractures, since the resistance to ow in the fractures is much smaller than that in the blocks. Flow in the blocks will be described by means of the usual Darcy and conservation laws [17]. Flow in the fractures will also be described using Darcy's law; this implies that the fractures will be t

Jim Douglas, Jr.

1987-01-01T23:59:59.000Z

14

The imbibition process of waterflooding in naturally fractured reservoirs  

E-Print Network (OSTI)

This thesis presents procedures to properly simulate naturally fractured reservoirs using dual-porosity models. The main objectives of this work are to: (1) determine if the spontaneous imbibition can be simulated using a two phase CMG simulator and validate it with laboratory experiments in the literature; (2) study the effect of countercurrent imbibition in field scale applications; and (3) develop procedures for using the dual-porosity to simulate fluid displacement in a naturally fractured reservoir. Reservoir simulation techniques, analytical solutions and numerical simulation for a two phase single and dual-porosity are used to achieve our objectives. Analysis of a single matrix block with an injector and a producer well connected by a single fracture is analyzed and compared with both two phase single and dual-porosity models. Procedures for obtaining reliable results when modeling a naturally fractured reservoir with a two phase dual-porosity model are presented and analyzed.

Huapaya Lopez, Christian A.

2003-12-01T23:59:59.000Z

15

Evaluation of borehole electromagnetic and seismic detection of fractures  

DOE Green Energy (OSTI)

Experiments were conducted to establish the feasibility of downhole high-frequency techniques for location of fractures in the vicinity of boreholes. An existing flame-cut slot in granite was filled with salt water to simulate a brine-filled fracture. The first method used an electromagnetic wave at 30 to 300 MHz, vhf frequencies. A transmitter consisting of a phased dual-dipole array arranged to provide a directional signal toward the fracture was installed in a borehole opposite the fracture. A receiver was also located in the same borehole. The radar returns from the simulated fracture were detectable in boreholes located at distances of up to 12 meters from the fracture. These results indicate for the first time the feasibility of a downhole vhf radar for use in a single borehole for detection of fractures located away from the borehole. Similar experiments were also conducted using seismic waves at 4.5 to 6 KHz. The transmitter and the receiver in this case were located in separate boreholes. During this experiment, reflections from the slot were obtained only with the transducers oriented for shear wave illumination and detection. These results suggest that a high-frequency shear wave can also be used to detect fractures away from a borehole.

Chang, H.T.; Suhler, S.A.; Owen, T.E.

1984-02-01T23:59:59.000Z

16

Fracture detection and characterization for geothermal reservoir definition  

DOE Green Energy (OSTI)

Fracture detection and mapping techniques are discussed as follows: remote-sensing, surface, borehold (including borehold-to-borehole), and surface-to-borehole. Other experimental techniques and research needs are described. (MHR)

Goldstein, N.E.

1984-12-01T23:59:59.000Z

17

Pressure testing of a high temperature naturally fractured reservoir  

DOE Green Energy (OSTI)

Los Alamos National Laboratory has conducted a number of pumping and flow-through tests at the Hot Dry Rock (HDR) test site at Fenton Hill, New Mexico. These tests consisted of injecting fresh water at controlled rates up to 12 BPM (32 l/s) and surface pressures up to 7000 psi (48 MPa) into the HDR formation at depths from 10,000 to 13,180 feet (3050 to 4000 m). The formation is a naturally fractured granite at temperatures of about 250/sup 0/C. The matrix porosity is <1% and permeability is on the order of 1 nD. Hence most of the injected fluid is believed to move through fractures. There has been no evidence of fracture breakdown phenomena, and hence it is believed that preexisting joints in the formation are opened by fluid injection. Water losses during pumping are significant, most likely resulting from flow into secondary fractures intersecting the main fluid conducting paths. The pressure-time response observed in these tests can be interpreted in terms of non-isothermal, fracture-dominated flow. As the fluid pressure increases from small values to those comparable to fracturing pressures, the formation response changes from linear fracture flow to the highly nonlinear situation where fracture lift-off occurs. A numerical heat and mass flow model was used to match the observed pressure response. Good matches were obtained for pressure buildup and shut-in data by assigning pressure dependent fracture and leak-off permeabilities. 12 refs., 5 figs., 2 tabs.

Kelkar, S.M.; Zyvoloski, G.A.; Dash, Z.V.

1986-01-01T23:59:59.000Z

18

Bone scanning in the detection of occult fractures  

SciTech Connect

The potential role of bone scanning in the early detection of occult fractures following acute trauma was investigated. Technetium 99m pyrophosphate bone scans were obtained in patients with major clinical findings and negative or equivocal roentgenograms following trauma. Bone scanning facilitated the prompt diagnosis of occult fractures in the hip, knee, wrist, ribs and costochondral junctions, sternum, vertebrae, sacrum, and coccyx. Several illustrative cases are presented. Roentgenographic confirmation occurred following a delay of days to weeks and, in some instances, the roentgenographic findings were subtle and could be easily overlooked. This study demonstrates bone scanning to be invaluable and definitive in the prompt detection of occult fractures.

Batillas, J.; Vasilas, A.; Pizzi, W.F.; Gokcebay, T.

1981-07-01T23:59:59.000Z

19

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

SciTech Connect

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

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

2013-06-15T23:59:59.000Z

20

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

DOE Green Energy (OSTI)

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

Goldstein, N.E.

1984-11-01T23:59:59.000Z

Note: This page contains sample records for the topic "natural fracture detection" 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

Creating permeable fracture networks for EGS: Engineered systems versus nature  

DOE Green Energy (OSTI)

The United States Department of Energy has set long-term national goals for the development of geothermal energy that are significantly accelerated compared to historical development of the resource. To achieve these goals, it is crucial to evaluate the performance of previous and existing efforts to create enhanced geothermal systems (EGS). Two recently developed EGS sites are evaluated from the standpoint of geomechanics. These sites have been established in significantly different tectonic regimes: 1. compressional Cooper Basin (Australia), and 2. extensional Soultz-sous-Fôrets (France). Mohr-Coulomb analyses of the stimulation procedures employed at these sites, coupled with borehole observations, indicate that pre-existing fractures play a significant role in the generation of permeability networks. While pre-existing fabric can be exploited to produce successful results for geothermal energy development, such fracture networks may not be omnipresent. For mostly undeformed reservoirs, it may be necessary to create new fractures using processes that merge existing technologies or use concepts borrowed from natural hydrofracture examples (e.g. dyke swarms).

Stephen L Karner

2005-10-01T23:59:59.000Z

22

Feasibility of an acoustic technique for fracture detection  

DOE Green Energy (OSTI)

A field experiment was conducted at a granite quarry to determine the feasibility of an acoustic, downhole technique for location of fractures in the vicinity of boreholes. The frequency used in this test was about 5 kHz; a frequency well above the seismic frequency commonly used in reservoir evaluations. An existing flame-cut slot in the granite at the test site was filled with water to simulate a fracture. A high-energy piezoelectric transmitter was located in a borehole 8 meters from the water-filled slot, and a commercial piezoelectric transducer was used as a receiver in a borehole 4 meters from the slot. Both transducers could be rotated for maximum transmission or reception for either the compressional wave or the shear wave. During the experiment, reflections from the simulated fracture were obtained with the transducers oriented only for shear wave illumination and detection. These test results suggest that a high-frequency shear wave can be used to detect fractures located away from a borehole. 2 refs., 2 figs.

Chang, H.T.

1985-01-01T23:59:59.000Z

23

Probabilistic pipe fracture evaluations for leak-rate-detection applications  

SciTech Connect

Regulatory Guide 1.45, {open_quotes}Reactor Coolant Pressure Boundary Leakage Detection Systems,{close_quotes} was published by the U.S. Nuclear Regulatory Commission (NRC) in May 1973, and provides guidance on leak detection methods and system requirements for Light Water Reactors. Additionally, leak detection limits are specified in plant Technical Specifications and are different for Boiling Water Reactors (BWRs) and Pressurized Water Reactors (PWRs). These leak detection limits are also used in leak-before-break evaluations performed in accordance with Draft Standard Review Plan, Section 3.6.3, {open_quotes}Leak Before Break Evaluation Procedures{close_quotes} where a margin of 10 on the leak detection limit is used in determining the crack size considered in subsequent fracture analyses. This study was requested by the NRC to: (1) evaluate the conditional failure probability for BWR and PWR piping for pipes that were leaking at the allowable leak detection limit, and (2) evaluate the margin of 10 to determine if it was unnecessarily large. A probabilistic approach was undertaken to conduct fracture evaluations of circumferentially cracked pipes for leak-rate-detection applications. Sixteen nuclear piping systems in BWR and PWR plants were analyzed to evaluate conditional failure probability and effects of crack-morphology variability on the current margins used in leak rate detection for leak-before-break.

Rahman, S.; Ghadiali, N.; Paul, D.; Wilkowski, G. [Battelle, Columbus, OH (United States)

1995-04-01T23:59:59.000Z

24

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

Science Conference Proceedings (OSTI)

The second year of this 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 overall 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 have been conducted with a dual porosity simulator capable of simulating the performance of vertical and horizontal wells. Each simulation model has been initialized with properties typical of the Austin Chalk reservoir in Pearsall Field, Texas. During year one, simulations of both vertical and horizontal well performance were made assuming that fracture permeability was insensitive to pressure charge. The results confirmed that horizontal wells could increase both rate of oil recovery and total oil recovery from naturally fractured reservoirs. During the second year the performances of the same vertical and horizontal wells were evaluated with the assumption that fracture permeability was a function of reservoir pressure. This required repetition of most of the natural depletion cases simulated in year one while invoking the pressure-sensitive fracture permeability option. To investigate sensitivity to in situ stress, two stress conditions were simulated for each primary variable. The water injection cases, begun in year one, were extended to include most of the reservoir parameters investigated for natural depletion, including fracture permeability as a function of net stress and the use of horizontal wells. The results thus far confirm that pressure-sensitive fractures degrade well performance and that the degradation is reduced by water injection pressure maintenance. Furthermore, oil recovery can be significantly increased by water injection pressure maintenance.

Not Available

1992-11-01T23:59:59.000Z

25

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

SciTech Connect

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

26

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

Science Conference Proceedings (OSTI)

This report describes the work performed during the fourth 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 artificially fractured cores (AFCs) and X-ray CT scanner to examine the physical mechanisms of bypassing in hydraulically fractured reservoirs (HFR) and naturally fractured reservoirs (NFR) that eventually result in more efficient CO{sub 2} flooding in heterogeneous or fracture-dominated reservoirs. In Chapter 1, we worked with DOE-RMOTC to investigate fracture properties in the Tensleep Formation at Teapot Dome Naval Reserve as part of their CO{sub 2} sequestration project. In Chapter 2, we continue our investigation to determine the primary oil recovery mechanism in a short vertically fractured core. Finally in Chapter 3, we report our numerical modeling efforts to develop compositional simulator with irregular grid blocks.

David S. Schechter

2005-04-27T23:59:59.000Z

27

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

SciTech Connect

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

28

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

SciTech Connect

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

29

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

Science Conference Proceedings (OSTI)

This report summarizes the work carried out during the period of September 29, 2000 to January 15, 2004 under DOE Research Contract No. DE-FC26-00BC15308. High temperatures and reactive fluids in sedimentary basins dictate that interplay and feedback between mechanical and geochemical processes significantly influence evolving rock and fracture properties. Not only does diagenetic mineralization fill in once open fractures either partially or completely, it modifies the rock mechanics properties that can control the mechanical aperture of natural fractures. In this study, we have evolved an integrated methodology of fractured reservoir characterization and we have demonstrated how it can be incorporated into fluid flow simulation. The research encompassed a wide range of work from geological characterization methods to rock mechanics analysis to reservoir simulation. With regard to the characterization of mineral infilling of natural fractures, the strong interplay between diagenetic and mechanical processes is documented and shown to be of vital importance to the behavior of many types of fractured reservoirs. Although most recent literature emphasizes Earth stress orientation, cementation in fractures is likely a critically important control on porosity, fluid flow attributes, and even sensitivity to effective stress changes. The diagenetic processes of dissolution and partial cementation are key controls on the creation and distribution of open natural fractures within hydrocarbon reservoirs. The continuity of fracture-porosity is fundamental to how fractures conduct fluids. In this study, we have made a number of important discoveries regarding fundamental properties of fractures, in particular related to the prevalence of kinematically significant structures (crack-seal texture) within otherwise porous, opening-mode fractures, and the presence of an aperture size threshold below which fractures are completely filled and above which porosity is preserved. These observations can be linked to models of quartz cementation. Significant progress has been made as well in theoretical fracture mechanics and geomechanical modeling, allowing prediction of spatial distributions of fractures that mimic patterns observed in nature. Geomechanical modeling shows the spatial arrangement of opening mode fractures (joints and veins) is controlled by the subcritical fracture index of the material. In particular, we have been able to identify mechanisms that control the clustering of fractures in slightly deformed rocks. Fracture mechanics testing of a wide range of clastic rocks shows that the subcritical index is sensitive to diagenetic factors. We show geomechanical simulations of fracture aperture development can be linked to diagenetic models, modifying fracture porosity as fractures grow, and affect the dynamics of fracture propagation. Fluid flow simulation of representative fracture pattern realizations shows how integrated modeling can give new insight into permeability assessment in the subsurface. Using realistic, geomechanically generated fracture patterns, we propose a methodology for permeability estimation in nonpercolating networks.

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

2004-11-01T23:59:59.000Z

30

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

E-Print Network (OSTI)

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

Johnson, S. Reed.

2007-01-01T23:59:59.000Z

31

Azimuthal Offset-Dependent Attributes (AVO And FVO) Applied To Fracture Detection  

E-Print Network (OSTI)

Using the amplitude versus offset (AVO) and the frequency versus offset (FVO) information, the diagnostic ability of P-wave seismic data in fracture detection is investigated. The offset-dependent attributes (AVO and FVO) ...

Shen, Feng

1999-01-01T23:59:59.000Z

32

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

Science Conference Proceedings (OSTI)

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

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

2004-05-01T23:59:59.000Z

33

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

SciTech Connect

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

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

2008-09-30T23:59:59.000Z

34

Designing cyclic pressure pulsing in naturally fractured reservoirs using an inverse looking recurrent neural network  

Science Conference Proceedings (OSTI)

In this paper, an inverse looking approach is presented to efficiently design cyclic pressure pulsing (huff 'n' puff) with N"2 and CO"2, which is an effective improved oil recovery method in naturally fractured reservoirs. A numerical flow simulation ... Keywords: Big Andy Field, CO2, Cyclic pressure pulsing, Huff 'n' puff, N2, Recurrent neural networks

E. Artun; T. Ertekin; R. Watson; B. Miller

2012-01-01T23:59:59.000Z

35

Acoustic methods for detecting water-filled fractures using commercial logging tools  

DOE Green Energy (OSTI)

The Los Alamos Scientific Laboratory Hot Dry Rock Geothermal Energy Development Project, under the Department of Energy and in cooperation with Dresser Atlas, has conducted single- and dual-well acoustic measurements to detect fractures in the artificial geothermal reservoir at the Fenton Hill New Mexico experimental site. The measurements were made using modified Dresser Atlas logging tools. Signals traversed distances of from 48 to 150 feet between two wells. Signals intersecting hydraulic fractures in the reservoir under both hydrostatic and pressurized conditions were simultaneously detected in both wells. Upon reservoir pressurization, signals along many ray paths were severely attenuated throughout their entire coda. In addition obvious shear wave arrivals were notably absent. The signals were processed to obtain Full-Wave Acoustic, Power, and Normalized Equi-Power Logs. Analysis of these logs identified the effective ''top'' of a region of hydraulically activated fractures and fractures intersecting the injection well behind casing.

Albright, J.N.; Aamodt, R.L.; Potter, R.M.; Spence, R.W.

1978-01-01T23:59:59.000Z

36

Detection and characterisation of planar fractures using a 3D Hough transform  

Science Conference Proceedings (OSTI)

In this article we propose an algorithmic approach - the detection and the characterization of planar fractures based on the analysis of 3D data relative to rock samples (coming from X-ray/NMR tomography). Data analysis is based on a particular implementation ... Keywords: Hough transform, plane detection, volumetric analysis

Augusto Sarti; Stefano Tubaro

2002-09-01T23:59:59.000Z

37

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

Science Conference Proceedings (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

38

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

E-Print Network (OSTI)

fracture model for multiphase ?ow in porous media. AIChEsingle- and multiphase transport in fractured porous media

Geiger, S.

2012-01-01T23:59:59.000Z

39

Modeling Wettability Alteration using Chemical EOR Processes in Naturally Fractured Reservoirs  

Science Conference Proceedings (OSTI)

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

Mojdeh Delshad; Gary A. Pope; Kamy Sepehrnoori

2007-09-30T23:59:59.000Z

40

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

Science Conference Proceedings (OSTI)

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

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

2003-04-01T23:59:59.000Z

Note: This page contains sample records for the topic "natural fracture detection" 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

Improving dual-porosity simulation of waterflood performance in the naturally fractured Spraberry Trend area  

E-Print Network (OSTI)

In this thesis we have discussed the methods of analyzing the waterflood performance of the O'Daniel waterflood pilot in the Spraberry Trend Area with the help of reservoir simulation. Spraberry Trend Area is considered to be one of the richest oil fields in the world. However, out of 6-10 billion bbls of original oil only 700 million bbls have been produced. In an effort to increase recovery, several waterflood pilots were conducted in Spraberry beginning in the late 1950's. Because of profoundly complicated nature of the reservoir, waterflooding has been only moderately successful, and billions of barrels of hydrocarbons remain unrecovered. A recent waterflood pilot study started in 1995 with dramatically different results. The pilot was conducted in the O'Daniel unit of the Spraberry. The recovery in this lease has exceeded 25% of the original oil in place, compared to only 10% recovery in the entire Spraberry. Data from the current waterflood clearly shows that on-trend wells which are outside the pilot and along the major fracture trend responded favorably. In the previous waterflood pilots in Spraberry, the producer located off-trend from the water injectors received all the attention and the response in the on-trend wells was overlooked. In this study, we have developed a waterflood pattern for Spraberry where the target wells for waterflood response will be the on-trend producers. A successful waterflood depends on properly positioning the injectors and producers. In fractured reservoirs, fracture location, orientation and permeability dictates the placing of injection and production wells. So, to understand the fracture distribution, the main intention behind this thesis is to develop a method to determine location, orientation and permeability of fractures in Spraberry by using reservoir simulation. We performed three simulation studies: Humble pilot waterflood, O'Daniel tracer analysis and O'Daniel pilot waterflood. The first two simulation studies were performed with simple two-well models. The fracture orientation and permeability ratio obtained in these models were applied to the full field O'Daniel pilot that consists of 59 wells in about 8500-acre area. Our simulation model shows that a concept of fracture enhancement (grid-blocks with high fracture permeability) in the dual-porosity model is necessary to capture the effect of heterogeneity of fracture network. The major fracture orientation obtained from the simulation is very close to the one obtained from the interference test and horizontal core analysis. The results of this study could be used in determining an optimum waterflood pattern suitable for that area to forecast oil production with different scenarios such as, infill drilling, CO2 injection, horizontal wells etc. Finally, the results of this work will provide a method to assess the economic feasibility of large-scale water injection in the remainder of the field.

Chowdhury, Tanvir

2002-01-01T23:59:59.000Z

42

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

E-Print Network (OSTI)

This thesis addresses the problem of removal of Naturally Occurring Radioactive Materials, NORM, and describes an effective alternative to the current treatment method for their removal. High-pen-meability fracturing, recently established in the petroleum industry, is the recommended technique. NORM are found throughout subterranean formations. Whenever fluids from petroleum or water reservoirs are produced NORM are present in varying quantities. NORM can only be sensed with radiation detectors. However, they have proven carcinogens, and the US Environmental Protection Agency has set a limit on the maximum contaminated level of any stream. Until now, the preferred method of treatment was to remove NORM from contaminated waters with specially designed filters, which in turn create a new problem. The same filters that are used to treat the water themselves become highly radioactive with a considerable disposal problem. In the petroleum industry, NORM become concentrated in the scale that is deposited inside the well or surface pipes. When scale is removed, it can be so radioactive that it can only be stored in toxic sites. Additionally, as water is produced along with oil, so are NORM. Until now, for the Gulf of Mexico at least, produced water has been released into the ocean, but the Environmental Protection Agency (EPA) is threatening to change this. In the North Sea the regulations are already stricter. There is then a compelling motivation to remove NORM before they are produced, and thus, eliminate the disposal problem. A high-permeability fracture design is presented which modifies existing petroleum practices by introducing within the proppant pack highly selective radionuclide sorbents. These sorbents, at calculated concentrations, can remove NORM readily for several years from typical flow rates containing typical NORM concentrations.

Demarchos, Andronikos Stavros

1998-01-01T23:59:59.000Z

43

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

E-Print Network (OSTI)

Fluid flow in three-dimensional (3D) fractured porous media is considered. The governing system of partial differential equations consists of two subsystems -- one describing the flow in the fractures, and the other describing the flow in the matrix blocks. In this paper, wedevelop an efficient algorithm for the numerical solution of the problem. An operator splitting technique is employed, as a part of the time-stepping procedure, to decouple the system into easy subsystems. The fracture concentration equation is discretized by the modified method of characteristics (MMOC) in time due to high velocityin the fractures and bytheRaviart-Thomas-Nedelec mixed method of index zero (RTN0) in space. The matrix concentration equation is discretized byabackward Euler scheme and the linear finite element method. The pressure equation is approximated byRTN0 and the linear Galerkin method for the fractures and the matrix blocks, respectively. For the fracture system, a domain decomposition (DD) it...

Seongjai Kim

2000-01-01T23:59:59.000Z

44

Laboratory and Field Measurements of Electrical Resistivity to Determine Saturation and Detect Fractures in a Heated Rock Mass  

DOE Green Energy (OSTI)

Laboratory measurements of the electrical resistivity of intact and fractured representative geothermal reservoir rocks were performed to investigate the resistivity contrast caused by active boiling and to infer saturation and fracture location in a large-scale field test. Measurements were performed to simulate test conditions with confining pressures up to 100 bars and temperatures to 145 C. Measurements presented are a first step toward making the search for fractures using electrical methods quantitatively. Intact samples showed a gradual resistivity increase when pore pressure was decreased below the phase-boundary pressure of free water, while fractured samples show a larger resistivity change at the onset of boiling. The resistivity change is greatest for samples with the most exposed surface area. Analysis of a field test provided the opportunity to evaluate fracture detection using electrical methods at a large scale. Interpretation of electrical resistance tomography (ERT) images of resistivity contrasts, aided by laboratory derived resistivity-saturation-temperature relationships, indicates that dynamic saturation changes in a heated rock mass are observable and that fractures experiencing drying or resaturation can be identified. The same techniques can be used to locate fractures in geothermal reservoirs using electrical field methods.

Roberts, J J; Ramirez, A; Carlson, S; Ralph, W; Bonner, B P

2001-04-03T23:59:59.000Z

45

A Coupled Model for Natural Convection and Condensation in Heated Subsurface Enclosures Embedded in Fractured Rock  

E-Print Network (OSTI)

and Mass Transfer in Yucca Mountain Drifts,” Proceedings ofMD- 000001 REV 00, Yucca Mountain Project Report, Bechtelthe fractured rock at Yucca Mountain have been investigated

Halecky, N.; Birkholzer, J.T.; Webb, S.W.; Peterson, P.F.; Bodvarsson, G.S.

2006-01-01T23:59:59.000Z

46

SIMULATION-ENHANCED FRACTURE DETECTION: RESEARCH AND DEMONSTRATION IN U.S. BASINS  

Science Conference Proceedings (OSTI)

Remote detection and characterization of fractured reservoirs is facilitated in this project by developing a revolutionary software system. The Model-Automated Geo-Informatics (MAGI) software integrates basin modeling, seismic data, synthetic seismic wave propagation and well data via information theory. The result is a seismic inversion cast in terms of fracture and other reservoir characteristics. The MAGI software was fully tested on synthetic data to verify program accuracy and robustness to data error. In Phase II, we (1) collected geological information (stratigraphic, structural, thermal, geochemical, fracturing and other information across the study area) (Task 4.1); (2) created a GIS database that is compatible with the input requirements of MAGI (Task 4.1); (3) implemented a web-based interface for user friendly access (Task 4.2); (4) gathered and preprocessed seismic data for input into MAGI; (5) developed two- and three-dimensional wave propagation simulators (in time domain) for fluid saturated porous media and implemented matching layer methodology for absorbing boundary conditions (Task 4.3); (6) developed parallel version of the seismic simulators (Task 4.3); (7) proposed an information theory framework that allows for the integration of multiple data types of a range of quality (Task 4.4); (8) developed and implemented highly efficient, parallel, Gauss-Newton seismic waveform inversion code based on reciprocity theorem (Task 4.5); (9) verified and demonstrated the accuracy and efficiency of the wave propagation and seismic waveform inversion codes (Tasks 4.3 and 4.5); and (10) identified the requirements for seismic data to allow seismic inversion (Task 4.6). With these accomplishments, we are prepared to carry out a demonstration in the Illinois Basin. A database of the proposed study area and the web-based system to facilitate geologic and seismic data input are ready for this demonstration as are mapping tools for comparison and observations.

Peter J. Ortoleva

2005-01-01T23:59:59.000Z

47

Fracture characterization study  

DOE Green Energy (OSTI)

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

Kehrman, R.F.

1978-04-01T23:59:59.000Z

48

Development of the optimized waterflooding pattern for the naturally fractured Spraberry Trend area  

E-Print Network (OSTI)

The Spraberry Trend area has produced oil since 1949 with a history of low productivity and unresponsive waterflooding within areas of interest in the field. It has been shown over the years that the conventional line drive waterflooding approach is highly ineffective in this field and there is a need to develop unique ways in which the reservoir can be waterflooded and produced. The reservoir model used for this study was developed in two distinct steps to speed up the development and ascertain the accuracy of the model. The preliminary model introduced only a single water injector while the final model included all the injectors around the area of interest. In developing the model, we found that the conventional simulation grid orientation which is normally employed in dynamic model building could not be applied to the Spraberry. Rather, fracture enhancements were introduced into the model to represent and model the complex fracture network. This proved valuable in validating the final reservoir model which was used for the various studies in this research. This thesis examined the influence of the distance and orientation of producers to injectors, water injection rate, fracture spacing and reservoir wettability in the effectiveness of waterflooding in the Spraberry with the hope that the distance and orientation of producers to injectors as well as the water injection rate can be optimized and implemented in the field. Furthermore it is hoped that this research will throw more light on how fracture spacing and matrix wettability affect the response of producers to water injectors. Reservoir simulation work contained in this thesis was performed on an 800 acre area of the O'Daniel pilot. Some of the results obtained validated earlier studies while other results provided new insights into the behavior of waterflooding in this reservoir. By systematically using the developed simulation model to confirm the production pattern observed in the field, the results obtained show that attention has to be paid to the orientation of the production wells relative to the water injectors and the dominant fractures. The effects of the fracture orientation and fracture spacing at various distances from the water injector were also investigated and it was concluded that if the producer is close to the water injector, the fracture orientation will dominate fluid movement while the farther the injector and producers are placed apart, the greater the influence of the fracture spacing on the fluid movement. Investigating the wettability, we found that with a high water matrix wettability, it was possible to optimize the injection rate. At low wettability however, we found that it is not possible to optimize the injection rate since the water injection rate has a somewhat inverse relationship with oil production. Finally, the result obtained by this research shows that fracture spacing of 10ft could be considered as the critical spacing, above which there is an insignificant effect of fracture spacing on the performance of the waterflooding in the Spraberry.

Dabiri, Adegoke

2002-01-01T23:59:59.000Z

49

A Parallelizable Method for Two-Phase Flows in Naturally-Fractured Reservoirs  

E-Print Network (OSTI)

; Felipe Pereira y Li-Ming Yeh z March 27, 2002 Abstract A parallelizable, semi-implicit numerical method-porosity, medium- block model as described in [15, 20] for the same type of ow, which corresponds to water-fractured medium. We will consider the water ooding problem in this paper; the groundwater problem

Douglas Jr., Jim

50

Advanced Reservoir Characterization and Evaluation of CO{sub 2} Gravity Drainage in the Naturally Fractured Spraberry Trend Area  

Science Conference Proceedings (OSTI)

The overall goal of this project is to assess the economic feasibility of CO{sub 2} flooding the naturally fractured Spraberry Trend Area in West Texas. This objective is being accomplished by conducting research in four areas: (1) extensive characterization of the reservoirs, (2) experimental studies of crude oil/brine/rock (COBR) interactions in the reservoirs, (3) reservoir performance analysis, and, (4) experimental investigations on CO2 gravity drainage in Spraberry whole cores. This report provides results of the third year of the five-year project for each of the four areas including a status report of field activities leading up to injection of CO2.

Schechter, D.S.

1999-02-03T23:59:59.000Z

51

Advanced Reservoir Characterization and Evaluation of CO2 Gravity Drainage in the Naturally Fractured Spraberry Trend Area, Class III  

Science Conference Proceedings (OSTI)

The goal of this project was to assess the economic feasibility of CO2 flooding the naturally fractured Spraberry Trend Area in west Texas. This objective was accomplished through research in four areas: (1) extensive characterization of the reservoirs, (2) experimental studies of crude oil/brine/rock (COBR) interactions in the reservoirs, (3) reservoir performance analysis, and (4) experimental investigations on CO2 gravity drainage in Spraberry whole cores. This provides results of the final year of the six-year project for each of the four areas.

Knight, Bill; Schechter, David S.

2002-07-26T23:59:59.000Z

52

TYPE CURVES FOR PRODUCTION TRANSIENT ANALYSIS OFMULTILATERAL WELLS IN NATURALLY FRACTURED SHALE GASRESERVOIRS.  

E-Print Network (OSTI)

??Growing demand for oil and natural gas and depletion of conventional reserves has led tothe advancement of technology to economically produce oil and natural gas… (more)

Saxena, Aditya

2012-01-01T23:59:59.000Z

53

High Altitude Aerial Natural Gas Leak Detection System  

SciTech Connect

The objective of this program was to develop and demonstrate a cost-effective and power-efficient advanced standoff sensing technology able to detect and quantify, from a high-altitude (> 10,000 ft) aircraft, natural gas leaking from a high-pressure pipeline. The advanced technology is based on an enhanced version of the Remote Methane Leak Detector (RMLD) platform developed previously by Physical Sciences Inc. (PSI). The RMLD combines a telecommunications-style diode laser, fiber-optic components, and low-cost DSP electronics with the well-understood principles of Wavelength Modulation Spectroscopy (WMS), to indicate the presence of natural gas located between the operator and a topographic target. The transceiver transmits a laser beam onto a topographic target and receives some of the laser light reflected by the target. The controller processes the received light signal to deduce the amount of methane in the laser's path. For use in the airborne platform, we modified three aspects of the RMLD, by: (1) inserting an Erbium-doped optical fiber laser amplifier to increase the transmitted laser power from 10 mW to 5W; (2) increasing the optical receiver diameter from 10 cm to 25 cm; and (3) altering the laser wavelength from 1653 nm to 1618 nm. The modified RMLD system provides a path-integrated methane concentration sensitivity {approx}5000 ppm-m, sufficient to detect the presence of a leak from a high capacity transmission line while discriminating against attenuation by ambient methane. In ground-based simulations of the aerial leak detection scenario, we demonstrated the ability to measure methane leaks within the laser beam path when it illuminates a topographic target 2000 m away. We also demonstrated simulated leak detection from ranges of 200 m using the 25 cm optical receiver without the fiber amplifier.

Richard T. Wainner; Mickey B. Frish; B. David Green; Matthew C. Laderer; Mark G. Allen; Joseph R. Morency

2006-12-31T23:59:59.000Z

54

Flashback Detection Sensor for Hydrogen Augmented Natural Gas Combustion  

DOE Green Energy (OSTI)

The use of hydrogen augmented fuel is being investigated by various researchers as a method to extend the lean operating limit, and potentially reduce thermal NOx formation in natural gas fired lean premixed (LPM) combustion systems. The resulting increase in flame speed during hydrogen augmentation, however, increases the propensity for flashback in LPM systems. Real-time in-situ monitoring of flashback is important for the development of control strategies for use of hydrogen augmented fuel in state-of-the-art combustion systems, and for the development of advanced hydrogen combustion systems. The National Energy Technology Laboratory (NETL) and Woodward Industrial Controls are developing a combustion control and diagnostics sensor (CCADS), which has already been demonstrated as a useful sensor for in-situ monitoring of natural gas combustion, including detection of important combustion events such as flashback and lean blowoff. Since CCADS is a flame ionization sensor technique, the low ion concentration produced in pure hydrogen combustion raises concerns of whether CCADS can be used to monitor flashback in hydrogen augmented combustion. This paper discusses CCADS tests conducted at 0.2-0.6 MPa (2-6 atm), demonstrating flashback detection with fuel compositions up to 80% hydrogen (by volume) mixed with natural gas. NETL’s Simulation Validation (SimVal) combustor offers full optical access to pressurized combustion during these tests. The CCADS data and high-speed video show the reaction zone moves upstream into the nozzle as the hydrogen fuel concentration increases, as is expected with the increased flame speed of the mixture. The CCADS data and video also demonstrate the opportunity for using CCADS to provide the necessary in-situ monitor to control flashback and lean blowoff in hydrogen augmented combustion applications.

Thornton, J.D.; Chorpening, B.T.; Sidwell, T.; Strakey, P.A.; Huckaby, E.D.; Benson, K.J. (Woodward)

2007-05-01T23:59:59.000Z

55

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

SciTech Connect

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

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

1997-06-01T23:59:59.000Z

56

BLOCKAGE DETECTION IN NATURAL GAS PIPELINES BY TRANSIENT ANALYSIS.  

E-Print Network (OSTI)

??Pipelines are the most reliable means for the transportation of natural gas. A major problem of flow assurance in natural gas pipelines is solid deposition… (more)

ADELEKE, NAJEEM

2010-01-01T23:59:59.000Z

57

Seismic detection of fractured Devonian shale reservoir. Annual report, July 1985-June 1986  

SciTech Connect

Interpretation of seismic data over the Cottageville gas field in West Virginia reveals the presence of numerous changes in reflection character across the top of the Lower Huron shales. Production from the Lower Huron is fracture-controlled, and some of the more-pronounced changes in amplitude and shape occur in the more-productive areas of the field. Model studies indicate that these changes are related to the development of low-impedance intervals that extend into the overlying shales of the Middle Huron. Analysis of geophysical logs indicates that these differences are not produced by lithologic variability in the shale. Hence, the observed changes in reflection character are believed to be associated with intense fracturing. Studies here suggest that the analysis of seismic data can be combined with other data to reduce the risk associated with exploration and development of Devonian shale gas resources. Final open-flow of gas and geologic structure from >4000 shale gas wells in eastern Kentucky outlines two high-flow areas. Interrelationships between geologic structure and gas flow are direct in one, but they are complex and unresolved in the other. Linear, steep flow gradients and the interrelationships of high-flow to structure confirm the importance of tectonic fracture permeability to shale productivity.

Wilson, T.H.; Shumaker, R.C.; Sims, C.S.

1986-07-01T23:59:59.000Z

58

Automatic detection of nocuous coordination ambiguities in natural language requirements  

Science Conference Proceedings (OSTI)

Natural language is prevalent in requirements documents. However, ambiguity is an intrinsic phenomenon of natural language, and is therefore present in all such documents. Ambiguity occurs when a sentence can be interpreted differently by different readers. ... Keywords: coordination ambiguity, human judgments, machine learning, natural language requirements, nocuous ambiguity

Hui Yang; Alistair Willis; Anne De Roeck; Bashar Nuseibeh

2010-09-01T23:59:59.000Z

59

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

SciTech Connect

The primary goal was to enter Phase 2 by analyzing geophysical logs and sidewall cores from a verification well drilled into the Trenton/Black River section along lineaments. However, the well has not yet been drilled; Phase 2 has therefore not been accomplished. Secondary goals in Phase I were also completed for the last reporting period. Thus, no new data were collected for this reporting period, and only soil gas surveys were reanalyzed and re-displayed in the region of the Trenton/Black River wells. The soil gas profiles in the region of the Trenton/Black River wells show that individual large-magnitude soil gas anomalies (spikes) are rarely wider than 50 m. Even clusters of soil gas spikes are only on the order of 200-250 m wide. Thus, widely-spaced sampling will not necessarily represent the actual number and location of soil gas seeps. The narrowness of the anomalies suggests that the seeps result from single fractures or narrow fracture intensification domains (FIDs). Many of the lineaments from EarthSat (1997) and straight stream segments coincide (or are very close to) soil gas spikes, but we collected many more soil gas spikes than lineaments. Among some of the soil gas box surveys, a possible ENE-trend of spikes can be discerned. This ENE-striking trend is, however, about 10{sup o} away from a nearby Earthsat (1997) trend. These data continue to demonstrate that integration of aeromagnetic and remote sensing lineaments, surface structure, soil gas and seismic allows us to extrapolate Trenton-Black River trends away from confirmatory seismic lines.

Robert Jacobi; John Fountain

2004-07-08T23:59:59.000Z

60

Effect of boundary conditions on the strength and deformability of replicas of natural fractures in welded tuff; Data report: Yucca Mountain Site Characterization Project  

Science Conference Proceedings (OSTI)

Four series of cyclic direct-shear experiments were conducted on several replicas of three natural fractures and a tensile fracture of welded tuff from Yucca Mountain. The objective of these tests was to examine the effect of cyclic loading on joint shear behavior under different boundary conditions. The shear tests were performed under either different levels of constant normal load ranging between 0.6 and 25.6 kips (2.7 and 113.9 kN) or constant normal stiffness ranging between 14.8 and 187.5 kips/in (25.9 and 328.1 kn/cm) . Bach test in the two categories consisted of five cycles of forward and reverse shear. Normal compression tests were also performed both before and after each shear experiment to measure changes in joint normal deformability. In order to quantify fracture surface damage during shear, fracture-surface fractal dimensions were obtained from measurements before and after shear.

Wibowo, J.; Amadei, B.; Sture, S.; Robertson, A.B. [Colorado Univ., Boulder, CO (United States). Dept. of Civil, Environmental, and Architectural Engineering; Price, R.H. [Sandia National Labs., Albuquerque, NM (United States)

1993-09-01T23:59:59.000Z

Note: This page contains sample records for the topic "natural fracture detection" 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

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

E-Print Network (OSTI)

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

Reynolds, Harris Allen

2012-01-01T23:59:59.000Z

62

Advanced reservoir characterization and evaluation of CO{sub 2} gravity drainage in the naturally fractured Spraberry reservoir. [Quarterly report], September 1, 1995--December 31, 1995  

Science Conference Proceedings (OSTI)

The objective of this research and the pilot project planned is to test the feasibility of CO{sub 2} for recovering oil from the naturally fractured Spraberry Trend Area in the Midland Basin. This notoriously marginal reservoir has confounded operators for 40 years with rapid depletion, low recovery during primary, disappointing waterflood results and low ultimate recovery. Yet, the tremendous areal coverage and large amount of remaining oil (up to 10 Bbbl) warrants further investigation to expend all possible process options before large numbers of Spraberry wellbores need to be plugged and abandoned. CO{sub 2} injection on a continuous, pattern wide basis has not been attempted in the Spraberry Trend. This is due to the obvious existence of a network of naturally occurring fractures. However, it has become clear in recent years that neglecting CO{sub 2} injection as an option in fractured reservoirs may overlook potential projects which may be viable. The 15 well pilot filed demonstration and supporting research will provide the necessary information to quantify the conditions where by CO{sub 2} flooding would be economic in the Spraberry Trend. Technical progress for this quarter is described for field and laboratory experiments.

Schechter, D. [New Mexico Petroleum Recovery Research Center, Socorro, NM (United States)

1995-12-31T23:59:59.000Z

63

2006 Nature Publishing Group Optical detection of liquid-state NMR  

E-Print Network (OSTI)

© 2006 Nature Publishing Group Optical detection of liquid-state NMR I. M. Savukov1 , S.-K. Lee1 & M. V. Romalis1 Nuclear magnetic resonance (NMR) in liquids and solids is primarily detected field itself provides only limited spatial or structural information about the sample. Most NMR

Romalis, Mike

64

Advanced reservoir characterization and evaluation of CO{sub 2} gravity drainage in the naturally fractured Spraberry Trend Area. Annual report, September 1, 1995--August 31, 1996  

SciTech Connect

The overall goal of this project is to assess the economic feasibility of CO{sub 2} flooding in the naturally fractured Spraberry Trend Area in West Texas. This objective is being accomplished by conducting research in four areas: (1) extensive characterization of the reservoirs, (2) experimental studies of crude oil/brine/rock (COBR) interaction in the reservoirs, (3) analytical and numerical simulation of Spraberry reservoirs, and, (4) experimental investigations on CO{sub 2} gravity drainage in Spraberry whole cores. This report provides results of the first year of the five-year project for each of the four areas.

Schechter, D.S.

1997-12-01T23:59:59.000Z

65

Field tests of probes for detecting internal corrosion of natural gas transmission pipelines  

Science Conference Proceedings (OSTI)

A field study was conducted to evaluate the use of electrochemical corrosion rate (ECR) probes for detecting corrosion in environments similar to those found in natural gas transmission pipelines. Results and interpretation will be reported from four different field tests. Flange and flush-mount probes were used in four different environments at a gas-gathering site and one environment but two different orientations at a natural gas plant. These sites were selected to represent normal and upset conditions in a gas transmission pipeline. The environments consisted of 2 different levels of humidified natural gas/organic/water mixtures removed from natural gas, and the environments at the 6 and 12 o'clock positions of a natural gas pipeline carrying 2-phase gas/liquid flow. Data are also presented comparing the ECR probe data to that for coupons used to determine corrosion rate and to detect the presence of microbiologically influenced corrosion (MIC).

Covino, Bernard S., Jr.; Bullard, Sophie J.; Cramer, Stephen D.; Holcomb, Gordon R.; Ziomek-Moroz, M.; Cayard, Michael S. (Intercorr International Inc.); Kane, Russell D. (Intercorr International Inc.); Meidinger, Brian (RMOTC-DOE)

2005-01-01T23:59:59.000Z

66

HYDRAULIC FRACTURING  

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

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

67

Tectonic Setting and Characteristics of Natural Fractures in MesaVerde and Dakota Reservoirs of the San Juan Basin  

SciTech Connect

The Cretaceous strata that fill the San Juan Basin of northwestern New Mexico and southwestern Colorado were shortened in a generally N-S to NN13-SSW direction during the Laramide orogeny. This shortening was the result of compression of the strata between southward indentation of the San Juan Uplift at the north edge of the basin and northward to northeastward indentation of the Zuni Uplift from the south. Right-lateral strike-slip motion was concentrated at the eastern and western basin margins of the basin to form the Hogback Monocline and the Nacimiento Uplift at the same time, and small amounts of shear may have been pervasive within the basin as well. Vertical extension fractures, striking N-S to NNE-SSW with local variations (parallel to the Laramide maximum horizontal compressive stress), formed in both Mesaverde and Dakota sandstones under this system, and are found in outcrops and in the subsurface of the San Juan Basin. The immature Mesaverde sandstones typically contain relatively long, irregular, vertical extension fractures, whereas the quartzitic Dakota sandstones contain more numerous, shorter, sub-parallel, closely spaced, extension fractures. Conjugate shear planes in several orientations are also present locally in the Dakota strata.

LORENZ,JOHN C.; COOPER,SCOTT P.

2000-12-20T23:59:59.000Z

68

Study on New Methods of Improving the Accuracy of Leak Detection and Location of Natural Gas Pipeline  

Science Conference Proceedings (OSTI)

As negative pressure wave is applied to leak detection and location of natural gas pipeline, the key is how to realize accurate measurement of propagation velocity of pressure wave and time difference. However, there exists problem of lower accuracy ... Keywords: natural gas pipeline, leak detection and location, negative pressure wave, wavelet transform, singularity detection

Shuqing Zhang; Tianye Gao; Hong Xu; Guangpu Hao; Zhongdong Wang

2009-04-01T23:59:59.000Z

69

Flight Testing of an Advanced Airborne Natural Gas Leak Detection System  

SciTech Connect

ITT Industries Space Systems Division (Space Systems) has developed an airborne natural gas leak detection system designed to detect, image, quantify, and precisely locate leaks from natural gas transmission pipelines. This system is called the Airborne Natural Gas Emission Lidar (ANGEL) system. The ANGEL system uses a highly sensitive differential absorption Lidar technology to remotely detect pipeline leaks. The ANGEL System is operated from a fixed wing aircraft and includes automatic scanning, pointing system, and pilot guidance systems. During a pipeline inspection, the ANGEL system aircraft flies at an elevation of 1000 feet above the ground at speeds of between 100 and 150 mph. Under this contract with DOE/NETL, Space Systems was funded to integrate the ANGEL sensor into a test aircraft and conduct a series of flight tests over a variety of test targets including simulated natural gas pipeline leaks. Following early tests in upstate New York in the summer of 2004, the ANGEL system was deployed to Casper, Wyoming to participate in a set of DOE-sponsored field tests at the Rocky Mountain Oilfield Testing Center (RMOTC). At RMOTC the Space Systems team completed integration of the system and flew an operational system for the first time. The ANGEL system flew 2 missions/day for the duration for the 5-day test. Over the course of the week the ANGEL System detected leaks ranging from 100 to 5,000 scfh.

Dawn Lenz; Raymond T. Lines; Darryl Murdock; Jeffrey Owen; Steven Stearns; Michael Stoogenke

2005-10-01T23:59:59.000Z

70

AIRBORNE, OPTICAL REMOTE SENSNG OF METHANE AND ETHANE FOR NATURAL GAS PIPELINE LEAK DETECTION  

SciTech Connect

Ophir Corporation was awarded a contract by the U. S. Department of Energy, National Energy Technology Laboratory under the Project Title ''Airborne, Optical Remote Sensing of Methane and Ethane for Natural Gas Pipeline Leak Detection'' on October 14, 2002. The scope of the work involved designing and developing an airborne, optical remote sensor capable of sensing methane and, if possible, ethane for the detection of natural gas pipeline leaks. Flight testing using a custom dual wavelength, high power fiber amplifier was initiated in February 2005. Ophir successfully demonstrated the airborne system, showing that it was capable of discerning small amounts of methane from a simulated pipeline leak. Leak rates as low as 150 standard cubic feet per hour (scf/h) were detected by the airborne sensor.

Jerry Myers

2005-04-15T23:59:59.000Z

71

Lipid Oxidation PathwaysChapter 6 Glycerophospholipid Core Aldehydes: Mechanism of Formation, Methods of Detection, Natural Occurrence, and Biological Significance  

Science Conference Proceedings (OSTI)

Lipid Oxidation Pathways Chapter 6 Glycerophospholipid Core Aldehydes: Mechanism of Formation, Methods of Detection, Natural Occurrence, and Biological Significance Health Nutrition Biochemistry eChapters Health - Nutrition - Biochemistr

72

Advanced Reservoir Characterization and Evaluation of CO{sub 2} Gravity Drainage in the Naturally Fractured Spraberry Trend Area, Class III  

Science Conference Proceedings (OSTI)

The goal of this project was to assess the economic feasibility of CO{sub 2} flooding the naturally fractured Spraberry Trend Area in west Texas. This objective was accomplished through research in four areas: (1) extensive characterization of the reservoirs, (2) experimental studies of crude oil/brine/rock (COBR) interactions in the reservoirs, (3) reservoir performance analysis, and (4) experimental investigations on CO{sub 2} gravity drainage in Spraberry whole cores. The four areas have been completed and reported in the previous annual reports. This report provides the results of the final year of the project including two SPE papers (SPE 71605 and SPE 71635) presented in the 2001 SPE Annual Meeting in New Orleans, two simulation works, analysis of logging observation wells (LOW) and progress of CO{sub 2} injection.

Knight, Bill; Schechter, David S.

2001-11-19T23:59:59.000Z

73

The Performance of Fractured Horizontal Well in Tight Gas Reservoir  

E-Print Network (OSTI)

Horizontal wells have been used to increase reservoir recovery, especially in unconventional reservoirs, and hydraulic fracturing has been applied to further extend the contact with the reservoir to increase the efficiency of development. In the past, many models, analytical or numerical, were developed to describe the flow behavior in horizontal wells with fractures. Source solution is one of the analytical/semi-analytical approaches. To solve fractured well problems, source methods were advanced from point sources to volumetric source, and pressure change inside fractures was considered in the volumetric source method. This study aims at developing a method that can predict horizontal well performance and the model can also be applied to horizontal wells with multiple fractures in complex natural fracture networks. The method solves the problem by superposing a series of slab sources under transient or pseudosteady-state flow conditions. The principle of the method comprises the calculation of semi-analytical response of a rectilinear reservoir with closed outer boundaries. A statistically assigned fracture network is used in the study to represent natural fractures based on the spacing between fractures and fracture geometry. The multiple dominating hydraulic fractures are then added to the natural fracture system to build the physical model of the problem. Each of the hydraulic fractures is connected to the horizontal wellbore, and the natural fractures are connected to the hydraulic fractures through the network description. Each fracture, natural or hydraulically induced, is treated as a series of slab sources. The analytical solution of superposed slab sources provides the base of the approach, and the overall flow from each fracture and the effect between the fractures are modeled by applying superposition principle to all of the fractures. It is assumed that hydraulic fractures are the main fractures that connect with the wellbore and the natural fractures are branching fractures which only connect with the main fractures. The fluid inside of the branch fractures flows into the main fractures, and the fluid of the main fracture from both the reservoir and the branch fractures flows to the wellbore. Predicting well performance in a complex fracture network system is extremely challenged. The statistical nature of natural fracture networks changes the flow characteristic from that of a single linear fracture. Simply using the single fracture model for individual fracture, and then adding the flow from each fracture for the network could introduce significant error. This study provides a semi-analytical approach to estimate well performance in a complex fracture network system.

Lin, Jiajing

2011-12-01T23:59:59.000Z

74

Rock deformation in hydrothermal systems: the nature of fractures in plutons and their host rocks. Technical progress report  

DOE Green Energy (OSTI)

The purpose of this program is to accumulate the types of field data which are important for the analysis of magma-hydrothermal systems. The structural effects of thermal processes were identified in order to distinguish the thermally induced deformations from the deformations that occurred subsequent to complete cooling of the system. Mapping techniques were developed to record the structural data on the ground from local domains characteristic of larger areas in the magma chamber, and in the air from low-angle oblique aerial photography of the entire region. The ground system is complete and preliminary testing is currently being carried out to verify the method. The results indicate that granitic crystalline rocks have no structural resistance to thermal perturbations. If nuclear wastes are to be stored in granite, precautionary buffers would have to be incorporated into the system. A total of 30 fossil magma chambers have been studied over the past 2 years. An extensive set of fracture imagery has been collected, together with information related to the geological history of the plutons. Fossil magma chambers in Arizona, Utah, California, Washington, Montana, and British Columbia have been studied.

Norton, D.

1981-11-01T23:59:59.000Z

75

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

SciTech Connect

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

LORENZ, JOHN C.; COOPER, SCOTT P.

2001-01-01T23:59:59.000Z

76

A probe for in situ, remote, detection of defects in buried plastic natural gas pipelines  

Science Conference Proceedings (OSTI)

Several techniques are available to determine the integrity of in situ metal pipeline but very little is available in the literature to determine the integrity of plastic pipelines. Since the decade of the 1970s much of the newly installed gas distribution and transmission lines in the United States are fabricated from polyethylene or other plastic. A probe has been developed to determine the in situ integrity of plastic natural gas pipelines that can be installed on a traversing mechanism (pig) to detect abnormalities in the walls of the plastic natural gas pipeline from the interior. This probe has its own internal power source and can be deployed into existing natural gas supply lines. Utilizing the capacitance parameter, the probe inspects the pipe for flaws and records the data internally which can be retrieved later for analysis.

Mathur, M.P.; Spenik, J.L.; Condon, C.M.; Monazam, E.R.; Fincham, W.L.

2007-12-18T23:59:59.000Z

77

Electrochemical corrosion rate sensors for detecting internal corrosion of natural gas transmission pipelines  

Science Conference Proceedings (OSTI)

This paper is a report on the evaluation of the use of electrochemical corrosion rate probes to detect internal corrosion in natural gas transmission pipeline environments. Flange and flush-mount probes were used in four different environments at three different sites that were selected to represent normal and upset conditions in a gas transmission pipeline. The environments consisted of humidified natural gas, organic/water mixtures removed from natural gas, and the environments at the 6 and 12 o'clock positions of a natural gas pipeline carrying multiphase gas/liquid flow. This paper will summarize and extend results presented previously and add additional data. A re-analysis of previously-reported data will be presented along with the results of physical examinations on the probes. New data on the measurement of corrosion in multiphase gas/liquid environments and for coupons used to determine corrosion rate and to detect the presence of microbiologically-influenced corrosion (MIC) will also be presented.

Covino, Bernard S., Jr.; Bullard, Sophie J.; Cramer, Stephen D.; Holcomb, Gordon R.; Ziomek-Moroz, M.; Kane, R.D. (Intercorr International Inc.); Eden, D.C. (Intercorr International Inc.)

2005-01-01T23:59:59.000Z

78

Investigation of Created Fracture Geometry through Hydraulic Fracture Treatment Analysis  

E-Print Network (OSTI)

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

Ahmed, Ibraheem 1987-

2012-12-01T23:59:59.000Z

79

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

E-Print Network (OSTI)

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

Aljeshi, Hussain Abdulhadi A.

2012-05-01T23:59:59.000Z

80

Natural Gas Weekly Update  

Annual Energy Outlook 2012 (EIA)

natural gas prices, successful application of horizontal drilling, and hydraulic fracturing, as well as significant investments made by natural gas companies in production...

Note: This page contains sample records for the topic "natural fracture detection" 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

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

Science Conference Proceedings (OSTI)

Hydraulic fracturing has been used widely to stimulate production of oil, natural gas, and geothermal energy in formations with low natural permeability. Numerical optimization of fracture stimulation often requires a large number of evaluations of objective ... Keywords: Fractal dimension, Global sensitivity, Hydraulic fracturing, Optimization, Surrogate model

Mingjie Chen, Yunwei Sun, Pengcheng Fu, Charles R. Carrigan, Zhiming Lu, Charles H. Tong, Thomas A. Buscheck

2013-08-01T23:59:59.000Z

82

Evaluating the Moisture Conditions in the Fractured Rock at Yucca Mountain: The Impact of Natural Convection Processes in Heated Emplacement Drifts  

E-Print Network (OSTI)

THE FRACTURED ROCK AT YUCCA MOUNTAIN: THE IMPACT OF NATURALgeologic repository at Yucca Mountain, Nevada, will stronglyWaste Emplacement Drifts at Yucca Mountain, Nevada, Nuclear

Birkholzer, J.T.; Webb, S.W.; Halecky, N.; Peterson, P.F.; Bodvarsson, G.S.

2005-01-01T23:59:59.000Z

83

A Handbook for the Application of Seismic Methods for Quantifying Naturally Fractured Gas Reservoirs in the San Juan Basin, New Mexico  

E-Print Network (OSTI)

Measured anisotropy in Pierre Shale: Geophys. Prosp. , 31,fractures embedded in sand-shale lithologies. The fractureto also correlate to the shale rich material and the greens

2004-01-01T23:59:59.000Z

84

Monitoring hydraulic fracture growth: Laboratory experiments  

Science Conference Proceedings (OSTI)

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

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

2000-04-01T23:59:59.000Z

85

Hydraulic Fracturing (Vermont)  

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

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

86

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

SciTech Connect

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

Gary Mavko

2000-10-01T23:59:59.000Z

87

Proceedings of the natural gas RD&D contractors review meeting, Volume I  

SciTech Connect

This report contains papers which were presented at the natural gas contractors review meeting held on April 4-6, 1995. Topics were concerned with resource and reserves, low permeability reservoir characterization, natural fracture detection, drilling, completion, and stimulation, and natural gas upgrading. Individual papers were processed separately for the United States Department of Energy databases.

Malone, R.D.

1995-04-01T23:59:59.000Z

88

Potential Contaminant Pathways from Hydraulically Fractured Shale to Aquifers  

E-Print Network (OSTI)

Potential Contaminant Pathways from Hydraulically Fractured Shale to Aquifers by Tom Myers Abstract Hydraulic fracturing of deep shale beds to develop natural gas has caused concern regarding the potential and preferential flow through fractures--could allow the transport of contaminants from the fractured shale

89

AIRBORNE, OPTICAL REMOTE SENSING OF METHANE AND ETHANE FOR NATURAL GAS PIPELINE LEAK DETECTION  

Science Conference Proceedings (OSTI)

Ophir Corporation was awarded a contract by the U. S. Department of Energy, National Energy Technology Laboratory under the Project Title ''Airborne, Optical Remote Sensing of Methane and Ethane for Natural Gas Pipeline Leak Detection'' on October 14, 2002. This six-month technical report summarizes the progress for each of the proposed tasks, discusses project concerns, and outlines near-term goals. Ophir has completed a data survey of two major natural gas pipeline companies on the design requirements for an airborne, optical remote sensor. The results of this survey are disclosed in this report. A substantial amount of time was spent on modeling the expected optical signal at the receiver at different absorption wavelengths, and determining the impact of noise sources such as solar background, signal shot noise, and electronic noise on methane and ethane gas detection. Based upon the signal to noise modeling and industry input, Ophir finalized the design requirements for the airborne sensor, and released the critical sensor light source design requirements to qualified vendors. Responses from the vendors indicated that the light source was not commercially available, and will require a research and development effort to produce. Three vendors have responded positively with proposed design solutions. Ophir has decided to conduct short path optical laboratory experiments to verify the existence of methane and absorption at the specified wavelength, prior to proceeding with the light source selection. Techniques to eliminate common mode noise were also evaluated during the laboratory tests. Finally, Ophir has included a summary of the potential concerns for project success and has established future goals.

Jerry Myers

2003-05-13T23:59:59.000Z

90

Development of Integrated Online Monitoring Systems for Detection of Diversion at Natural Uranium Conversion Facilities  

SciTech Connect

Recent work at Oak Ridge National Laboratory (ORNL) has focused on some source term modeling of uranyl nitrate (UN) as part of a comprehensive validation effort employing gamma-ray detector instrumentation for the detection of diversion from declared conversion activities. Conversion, the process by which natural uranium ore (yellowcake) is purified and converted through a series of chemical processes into uranium hexafluoride gas (UF6), has historically been excluded from the nuclear safeguards requirements of the 235U-based nuclear fuel cycle. The undeclared diversion of this product material could potentially provide feedstock for a clandestine weapons program for state or non-state entities. Given the changing global political environment and the increased availability of dual-use nuclear technology, the International Atomic Energy Agency has evolved its policies to emphasize safeguarding this potential feedstock material in response to dynamic and evolving potential diversion pathways. To meet the demand for instrumentation testing at conversion facilities, ORNL developed the Uranyl Nitrate Calibration Loop Equipment (UNCLE) facility to simulate the full-scale operating conditions of a purified uranium-bearing aqueous stream exiting the solvent extraction process in a natural uranium conversion plant. This work investigates gamma-ray signatures of UN circulating in the UNCLE facility and evaluates detector instrumentation sensitivity to UN for safeguards applications. These detector validation activities include assessing detector responses to the UN gamma-ray signatures for spectrometers based on sodium iodide, lanthanum bromide, and germanium detectors. The results of measurements under static and dynamic operating conditions at concentrations ranging from 10-90g U/L of naturally enriched UN will be presented. A range of gamma-ray lines was examined and self-attenuation factors were calculated, in addition to attenuation for transmission measurement of density, concentration and enrichment. A detailed uncertainty analysis will be presented providing insights into instrumentation limitations to spoofing.

Dewji, Shaheen A [ORNL; Lee, Denise L [ORNL; Croft, Stephen [ORNL; McElroy, Robert Dennis [ORNL; Hertel, Nolan [Georgia Institute of Technology; Chapman, Jeffrey Allen [ORNL; Cleveland, Steven L [ORNL

2013-01-01T23:59:59.000Z

91

Fractured shale reservoirs: Towards a realistic model  

Science Conference Proceedings (OSTI)

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

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

1996-09-01T23:59:59.000Z

92

SPALL FRACTURE AND SPALL FRACTURE AND COMPACTION COMPACTION  

National Nuclear Security Administration (NNSA)

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

93

Downhole tool sniffs out fractures  

SciTech Connect

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

Not Available

1987-05-01T23:59:59.000Z

94

Method for enhancement of sequential hydraulic fracturing using control pulse fracturing  

Science Conference Proceedings (OSTI)

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

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

1993-07-20T23:59:59.000Z

95

AIRBORNE, OPTICAL REMOTE SENSING OF METHANE AND ETHANE FOR NATURAL GAS PIPELINE LEAK DETECTION  

SciTech Connect

Ophir Corporation was awarded a contract by the U. S. Department of Energy, National Energy Technology Laboratory under the Project Title ''Airborne, Optical Remote Sensing of Methane and Ethane for Natural Gas Pipeline Leak Detection'' on October 14, 2002. This second six-month technical report summarizes the progress made towards defining, designing, and developing the hardware and software segments of the airborne, optical remote methane and ethane sensor. The most challenging task to date has been to identify a vendor capable of designing and developing a light source with the appropriate output wavelength and power. This report will document the work that has been done to identify design requirements, and potential vendors for the light source. Significant progress has also been made in characterizing the amount of light return available from a remote target at various distances from the light source. A great deal of time has been spent conducting laboratory and long-optical path target reflectance measurements. This is important since it helps to establish the overall optical output requirements for the sensor. It also reduces the relative uncertainty and risk associated with developing a custom light source. The data gathered from the optical path testing has been translated to the airborne transceiver design in such areas as: fiber coupling, optical detector selection, gas filters, and software analysis. Ophir will next, summarize the design progress of the transceiver hardware and software development. Finally, Ophir will discuss remaining project issues that may impact the success of the project.

Jerry Myers

2003-11-12T23:59:59.000Z

96

AIRBORNE, OPTICAL REMOTE SENSING OF METHANE AND ETHANE FOR NATURAL GAS PIPLINE LEAK DETECTION  

SciTech Connect

Ophir Corporation was awarded a contract by the U. S. Department of Energy, National Energy Technology Laboratory under the Project Title ''Airborne, Optical Remote Sensing of Methane and Ethane for Natural Gas Pipeline Leak Detection'' on October 14, 2002. The third six-month technical report contains a summary of the progress made towards finalizing the design and assembling the airborne, remote methane and ethane sensor. The vendor has been chosen and is on contract to develop the light source with the appropriate linewidth and spectral shape to best utilize the Ophir gas correlation software. Ophir has expanded upon the target reflectance testing begun in the previous performance period by replacing the experimental receiving optics with the proposed airborne large aperture telescope, which is theoretically capable of capturing many times more signal return. The data gathered from these tests has shown the importance of optimizing the fiber optic receiving fiber to the receiving optic and has helped Ophir to optimize the design of the gas cells and narrowband optical filters. Finally, Ophir will discuss remaining project issues that may impact the success of the project.

Jerry Myers

2004-05-12T23:59:59.000Z

97

Hydraulic fracturing-1  

Science Conference Proceedings (OSTI)

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

Not Available

1990-01-01T23:59:59.000Z

98

4. Natural Gas Statistics  

U.S. Energy Information Administration (EIA)

hydraulic fracturing, including shales and low permeability (tight) formations. Total U.S. dry natural gas reserves additions replaced 237 percent of 2007 dry

99

Oil Recovery Enhancement from Fractured, Low Permeability Reservoirs. [Carbonated Water  

DOE R&D Accomplishments (OSTI)

The results of the investigative efforts for this jointly funded DOE-State of Texas research project achieved during the 1990-1991 year may be summarized as follows: Geological Characterization - Detailed maps of the development and hierarchical nature the fracture system exhibited by Austin Chalk outcrops were prepared. The results of these efforts were directly applied to the development of production decline type curves applicable to a dual-fracture-matrix flow system. Analysis of production records obtained from Austin Chalk operators illustrated the utility of these type curves to determine relative fracture/matrix contributions and extent. Well-log response in Austin Chalk wells has been shown to be a reliable indicator of organic maturity. Shear-wave splitting concepts were used to estimate fracture orientations from Vertical Seismic Profile, VSP data. Several programs were written to facilitate analysis of the data. The results of these efforts indicated fractures could be detected with VSP seismic methods. Development of the EOR Imbibition Process - Laboratory displacement as well as Magnetic Resonance Imaging, MRI and Computed Tomography, CT imaging studies have shown the carbonated water-imbibition displacement process significantly accelerates and increases recovery from oil saturated, low permeability rocks. Field Tests - Two operators amenable to conducting a carbonated water flood test on an Austin Chalk well have been identified. Feasibility studies are presently underway.

Poston, S. W.

1991-00-00T23:59:59.000Z

100

Advanced reservoir characterization and evaluation of CO{sub 2} gravity drainage in the naturally fractured Spraberry Trend Area. First annual technical progress report, September 1, 1995--August 31, 1996  

SciTech Connect

The overall goal of this project is to assess the economic feasibility of CO{sub 2} flooding the naturally fractured Spraberry Trend Area in West Texas. This objective is being accomplished by conducting research in four areas: (1) extensive characterization of the reservoirs, (2) experimental studies of crude oil/brine/rock (COBR) interaction in the reservoirs, (3) analytical and numerical simulation of Spraberry reservoirs, and, (4) experimental investigations on CO{sub 2} gravity drainage in Spraberry whole cores. This report provides results of the first year of the five-year project for each of the four areas.

Schechter, D.S.

1996-12-17T23:59:59.000Z

Note: This page contains sample records for the topic "natural fracture detection" 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

Relative Permeability of Fractured Rock  

DOE Green Energy (OSTI)

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

Mark D. Habana

2002-06-30T23:59:59.000Z

102

Microseismic Tracer Particles for Hydraulic Fracturing  

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

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

103

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

SciTech Connect

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

Hoak, T.; Jenkins, R. [Science Applications International Corp., McLean, VA (United States); Ortoleva, P.; Ozkan, G.; Shebl, M.; Sibo, W.; Tuncay, K. [Laboratory for Computational Geodynamics (United States); Sundberg, K. [Phillips Petroleum Company (United States)

1998-07-01T23:59:59.000Z

104

Corporation Commission Hydraulic FracturingHydraulic Fracturing  

E-Print Network (OSTI)

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

Peterson, Blake R.

105

Detecting internal corrosion of natural gas transmission pipelines: field tests of probes and systems for real-time corrosion measurement  

Science Conference Proceedings (OSTI)

A field study was conducted to evaluate the use of automated, multi-technique electrochemical corrosion-rate monitoring devices and probes for detecting corrosion in environments similar to those found in natural gas transmission pipelines. It involved measurement of real-time corrosion signals from operating pipelines. Results and interpretation were reported from four different field test locations. Standard flush-mount and custom flange probes were used in four different environments at a gas-gathering site and one environment but two different probe orientations at a natural gas site. These sites were selected to represent normal and upset conditions common in gas transmission pipelines. The environments consisted of two different levels of humidified natural gas, liquid hydrocarbon, and water from natural gas. Probe locations included the 6 and 12 o?clock positions of a natural gas pipeline carrying 2-phase gas/liquid flow. The probe data was monitored using completely remote solar powered systems that provided real-time data transmission via wireless back to a pipeline control station. Data are also presented comparing the ECR probe data to that for coupons used to determine corrosion rate and to detect the presence of microbiologically influenced corrosion (MIC).

Covino, Bernard S., Jr.; Bullard, Sophie J.; Cramer, Stephen D.; Holcomb, Gordon R.; Ziomek-Moroz, M.; Kane, R.D. (InterCorr International); Meidinger, B. (Rocky Mountain Oilfield Testing Center)

2005-01-01T23:59:59.000Z

106

NETL: Oil & Natural Gas Technologies Reference Shelf - Presentation...  

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

in shales Natural fractures in shales: Origins, characteristics and relevance for hydraulic fracture treatments Authors: J. F. Gale and J. Holder Venue: 2008 American...

107

Natural  

Gasoline and Diesel Fuel Update (EIA)

Summary of U.S. Natural Gas Imports and Exports, 1992-1996 Table 1992 1993 1994 1995 1996 Imports Volume (million cubic feet) Pipeline Canada............................. 2,094,387 2,266,751 2,566,049 2,816,408 2,883,277 Mexico .............................. 0 1,678 7,013 6,722 13,862 Total Pipeline Imports....... 2,094,387 2,268,429 2,573,061 2,823,130 2,897,138 LNG Algeria .............................. 43,116 81,685 50,778 17,918 35,325 United Arab Emirates ....... 0 0 0 0 4,949 Total LNG Imports............. 43,116 81,685 50,778 17,918 40,274 Total Imports......................... 2,137,504 2,350,115 2,623,839 2,841,048 2,937,413 Average Price (dollars per thousand cubic feet) Pipeline Canada............................. 1.84 2.02 1.86 1.48 1.96 Mexico .............................. - 1.94 1.99 1.53 2.25 Total Pipeline Imports.......

108

Seismological investigation of crack formation in hydraulic rock fracturing experiments and in natural geothermal environments. Progress report, September 1, 1980-August 31, 1981  

DOE Green Energy (OSTI)

Progress is reported on the following: interpretation of seismic data from hydraulic fracturing experiments at the Fenton Hill Hot Dry Rock Geothermal Site, interpretation of 3-D velocity anomalies in the western US with special attention to geothermal areas, theoretical and observational studies of scattering and attenuation of high-frequency seismic waves, theoretical and observational studies of volcanic tremors in relation to magma transport mechanisms, and deployment and maintenance of 9 event-recorders around Mt. St. Helens. Abstracts of papers submitted for publication are included. (MHR)

Aki, K.

1981-09-01T23:59:59.000Z

109

Hydraulic Fracturing | Open Energy Information  

Open Energy Info (EERE)

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

110

Hydrodynamics of a vertical hydraulic fracture  

DOE Green Energy (OSTI)

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

Narasimhan, T.N.

1987-03-24T23:59:59.000Z

111

Hydraulic Fracturing and Water Use in Dallas, Texas.  

E-Print Network (OSTI)

??Dallas, Texas is located in North Texas and sits above the eastern portion of the Barnett Shale natural gas formation. Hydraulic fracturing, or fracking, was… (more)

Yates, Sarah

2013-01-01T23:59:59.000Z

112

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

Open Energy Info (EERE)

nearly parallel to the maximum horizontal stress. In this favorable situation, hydraulic injections will tend both to reactivate natural fractures at low pressures, and to...

113

Linear Elastic Fracture Mechanics  

Science Conference Proceedings (OSTI)

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

114

Natural Gas from Shale | Department of Energy  

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

Natural Gas from Shale Natural Gas from Shale Office of Fossil Energy research helped refine cost-effective horizontal drilling and hydraulic fracturing technologies, protective...

115

Laser system for natural gas detection. Phase I. Laboratory feasibility studies  

SciTech Connect

Laboratory and field tests successfully proved the feasibility of laser remote sensing as a leak-survey tool in gas distribution systems. Using a pair of helium neon lasers to measure methane, the device exhibited at a 43-ft range a methane detection limit of 3 ppm in a gas plume with a 3.3-ft path length.

Grant, W.B.; Hinkley, E.D.

1981-12-01T23:59:59.000Z

116

Hydrogen-Assisted Fracture: Materials Testing and Variables Governing Fracture  

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

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

117

Interactive fracture design model  

DOE Green Energy (OSTI)

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

Not Available

1980-05-01T23:59:59.000Z

118

Estimating fracture apertures from hydraulic data and comparison with theory  

DOE Green Energy (OSTI)

Estimates of fracture openings, or apertures, were made for massive hydraulic fracture experiments at the Hot Dry Rock geothermal reservoir at Fenton Hill, New Mexico. The basis of these estimates is that if the injection rate is suddenly increased during fracturing, and the subsequent pressure increase to sustain this additional flow is measured, then the pressure increase must be related to the fracture aperture. More detailed considerations indicate that the fracture aperture estimated in this manner is affected by the nature of the fracture geometry, its propagation distance, and its viscous characteristics, but these effects are surprisingly unimportant. The result is a reasonably accurate aperture estimate, which considering the elusive nature of this measurement by other means, is quite satisfactory. These estimates are in good agreement with the fracturing theory of Geertsma and de Klerk. 10 refs., 6 figs.

Dash, Z.V.; Murphy, H.D.

1985-01-01T23:59:59.000Z

119

Hydraulic Fracturing Technology | Department of Energy  

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

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

120

Feasibility of a borehole VHF radar technique for fracture mapping  

DOE Green Energy (OSTI)

Experiments were conducted to establish the feasibility of a downhole high-frequency electromagnetic technique for location of fractures in the vicinity of boreholes. An existing flame-cut slot in granite was filled with salt water to simulate a brine-filled fracture. A transmitter consisting of a phased dual-dipole array arranged to provide a directional signal toward the fracture was installed in a borehole opposite the fracture. A receiver operated at 30 to 300 MHz was also located in the same borehole. The radar returns from the simulated fracture were detectable in boreholes located at distances of up to 12 meters from the fracture. These results indicate for the first time the feasibility of a downhole VHF radar for use in a single borehole for detection of fractures located away from the borehole.

Chang, H.T.

1984-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "natural fracture detection" 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

A Thermoelastic Hydraulic Fracture Design Tool for Geothermal Reservoir Development  

DOE Green Energy (OSTI)

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

Ahmad Ghassemi

2003-06-30T23:59:59.000Z

122

NETL: Oil & Natural Gas Technologies Reference Shelf - Presentation...  

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

Natural Fractures in the Barnett Shale in the Delaware Basin Natural Fractures in the Barnett Shale in the Delaware Basin, Pecos Co. West Texas: comparison with the Barnett Shale...

123

High velocity impact fracture  

E-Print Network (OSTI)

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

Teng, Xiaoqing

2005-01-01T23:59:59.000Z

124

Assessing a Spectroelectrochemical Sensor's Performance for Detecting [Ru(bpy)3]2+ in Natural and Treated Water  

Science Conference Proceedings (OSTI)

A spectroelectrochemical sensor that combines three modes of selectivity in a single device was evaluated in natural and treated water samples using tris-(2,2’-bipyridyl) ruthenium(II) dichloride hexahydrate, [Ru(bpy)3]2+, as a model analyte. The sensor was an optically transparent indium tin oxide (ITO) electrode coated with a thin film of partially sulfonated polystyrene-block-poly(ethylene-ran-butylene)-block-polystyrene (SSEBS). As the potential of the ITO electrode was cycled from +0.7 to +1.3 V, the analyte changed from the colored [Ru(bpy)3]2+ complex to colorless [Ru(bpy)3]3+ complex and the change in absorbance at 450 nm was used as the optical signal for quantification. Calibration curves were obtained for [Ru(bpy)3]2+ in natural well water, river water and treated tap water with detection limits of 108, 139 and 264 nM, respectively. A standard addition method was developed to determine an *unknown* spike addition concentration of [Ru(bpy)3]2+ in well water. The spectroelectrochemical sensor determined the concentration of [Ru(bpy)3]2+ spiked into a sample of Hanford well water to be 0.39*0.03 mM versus the actual concentration of 0.40 mM.

Abu, Eme A.; Bryan, Samuel A.; Seliskar, Carl J.; Heineman, William R.

2012-07-01T23:59:59.000Z

125

Horizontal drilling boosts Pennsylvania’s natural gas production ...  

U.S. Energy Information Administration (EIA)

Between 2009 and 2011, Pennsylvania's natural gas production more than quadrupled due to expanded horizontal drilling combined with hydraulic fracturing.

126

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

DOE Green Energy (OSTI)

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

Hebein, Jeffrey J.

1986-01-21T23:59:59.000Z

127

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

E-Print Network (OSTI)

Hydraulic fracture conductivity in ultra-low permeability shale reservoirs is directly related to well productivity. The main goal of hydraulic fracturing in shale formations is to create a network of conductive pathways in the rock which increase the surface area of the formation that is connected to the wellbore. These highly conductive fractures significantly increase the production rates of petroleum fluids. During the process of hydraulic fracturing proppant is pumped and distributed in the fractures to keep them open after closure. Economic considerations have driven the industry to find ways to determine the optimal type, size and concentration of proppant that would enhance fracture conductivity and improve well performance. Therefore, direct laboratory conductivity measurements using real shale samples under realistic experimental conditions are needed for reliable hydraulic fracturing design optimization. A series of laboratory experiments was conducted to measure the conductivity of propped and unpropped fractures of Barnett shale using a modified API conductivity cell at room temperature for both natural fractures and induced fractures. The induced fractures were artificially created along the bedding plane to account for the effect of fracture face roughness on conductivity. The cementing material present on the surface of the natural fractures was preserved only for the initial unpropped conductivity tests. Natural proppants of difference sizes were manually placed and evenly distributed along the fracture face. The effect of proppant monolayer was also studied.

Kamenov, Anton

2013-05-01T23:59:59.000Z

128

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

129

EPA's Natural Gas Extraction -- Hydraulic Fracturing Website...  

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

enabling greater access to gas in shale formations. Responsible development of America's shale gas resources offers important economic, energy security, and environmental...

130

RATE DECLINE ANALYSIS FOR NATURALLY FRACTURED RESERVOIRS  

E-Print Network (OSTI)

differential equation gives: 1 6 porn = -&(to) (7; - 1) +P Df (A38) Differentiating Eqn. A.88, evaluating at V the matrix radius: #12;APPENDIX A. DERNATION OF SOLUTION 58 Then: & ( f ~ ) l o v g = 9( P D ~-porn). Eqns. A

Stanford University

131

Enhanced oil recovery through water imbibition in fractured reservoirs using Nuclear Magnetic Resonance.  

E-Print Network (OSTI)

??Conventional waterflooding methods of oil recovery are difficult to apply when reservoirs show evidence of natural fractures, because injected water advances through paths of high… (more)

Hervas Ordonez, Rafael Alejandro

2012-01-01T23:59:59.000Z

132

Radon in Soil Gas Above Bedrock Fracture Sets at the Shepley’s Hill Superfund Site  

Science Conference Proceedings (OSTI)

The Idaho National Laboratory (INL) recently provided technical support for ongoing environmental remediation activities at the Shepley’s Hill remediation site near Devens, MA (Figure 1). The technical support was requested as follow-on work to an initial screening level radiation survey conducted in 2008. The purpose of the original study was to assess the efficacy of the INL-developed Backpack Sodium Iodide System (BaSIS) for detecting elevated areas of natural radioactivity due to the decay of radon-222 gases emanating from the underlying fracture sets. Although the results from the initial study were mixed, the BaSIS radiation surveys did confirm that exposed bedrock outcrops have higher natural radioactivity than the surficial soils, thus a high potential for detecting elevated levels of radon and/or radon daughter products. (INL 2009) The short count times associated with the BaSIS measurements limited the ability of the system to respond to elevated levels of radioactivity from a subsurface source, in this instance radon gas emanating from fracture sets. Thus, it was postulated that a different methodology be employed to directly detect the radon in the soil gases. The CR-39 particle track detectors were investigated through an extensive literature and technology search. The relatively long deployment or “detection” time of several days, as well as the sensitivity of the measurement and robustness of the detectors made the CR-39 technology promising for deployment at the Shepley’s Hill site.

J.R. Giles; T.L. McLing; M.V. Carpenter; C.J. Smith; W. Brandon

2012-12-01T23:59:59.000Z

133

Fractured reservoir characterization through injection, falloff, and flowback tests  

SciTech Connect

This paper presents the development of a multiphase pressure-transient-analysis technique for naturally fractured reservoirs and the analysis of a series of field tests performed to evaluate the water injection potential and the reservoir characteristics of a naturally fractured reservoir. These included step-rate, water-injectivity, pressure-falloff, and flowback tests. Through these tests, a description of the reservoir was obtained.

Peng, C.P.; Singh, P.K. (Amoco Production Co., Tulsa, OK (United States)); Halvorsen, H. (Amoco Norway Oil Co., Stavanger (NO)); York, S.D. (Amoco Production Co., Houston, TX (United States))

1992-09-01T23:59:59.000Z

134

A Rare Isolated Trapezoid Fracture  

E-Print Network (OSTI)

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

Afifi, Negean; Lu, Jenny J

2011-01-01T23:59:59.000Z

135

Hydraulic Fracturing in Particulate Materials .  

E-Print Network (OSTI)

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

Chang, Hong

2004-01-01T23:59:59.000Z

136

Fold Catastrophe Model of Fracture Propagation of Hydraulic Fracturing  

Science Conference Proceedings (OSTI)

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

Zhaowan Chun; Wan Tingting; Ai Chi; Ju Guoshuai

2010-05-01T23:59:59.000Z

137

NETL: Oil & Natural Gas Technologies Reference Shelf - Presentation on  

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

Natural Fractures in the Barnett Shale in the Delaware Basin Natural Fractures in the Barnett Shale in the Delaware Basin Natural Fractures in the Barnett Shale in the Delaware Basin, Pecos Co. West Texas: comparison with the Barnett Shale in the Fort Worth Basin Authors: Julia F. W. Gale Venue: West Texas Geological Society Symposium, in Midland, Texas September 10-12, 2008. http://www.wtgs.org [external site] Abstract: This study describes the several sets of natural fractures in a Barnett Shale core from Pecos County, including partly open fractures, fractures associated with chert layers and early, deformed fractures. These are compared with fractures previously described in the Barnett Shale in the Fort Worth Basin. The basic fracture attributes are discussed in terms of their implications for hydraulic fracture treatments. The steep, narrow, calcite-sealed fractures that are present in many Barnett cores in the Fort Worth Basin are important because of their likely tendency to reactivate during hydraulic fracture treatments. Larger open fractures are possibly present, clustered on the order of several hundred feet apart. In the core studied from the Delaware Basin there is evidence that a greater number of narrower fractures may be open. Thus, their importance for completions may be rather different than those in the Fort Worth Basin

138

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

E-Print Network (OSTI)

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

Lolon, Elyezer P.

2004-12-01T23:59:59.000Z

139

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 treatment for such formation and even more difficult is to describe production behavior using a reservoir model. So far homogeneous, two wing fracture, and natural fracture models have been used for this purpose without much success. Micro seismic mapping technique is used to measure the fracture propagation in real time. This measurement in naturally fractured shale formation suggests a growth of fracture network instead of a traditional two wing fractures. There is an industry wise consensus that fracture network plays an important role in determining the well productivity of such formations. A well with high density of fracture networks supposed to have better productivity. Shale formations have also exhibited production pattern which is very different from conventional or tight gas reservoir. Initial flow period is marked by steep decline in production while the late time production exhibits a slow decline. One of the arguments put for this behavior is linear flow from a bi-wing fractured well at early time and contribution of adsorbed gas in production at late time. However, bi-wing fracture geometry is not supported by the micro-seismic observation. A realistic model should include both the fracture network and adsorbed gas property. In this research we have proposed a new Power Law Permability model to simulate fluid flow from hydraulically fractured Shale formation. This model was first described by Valko & Fnu (2002) and used for analyzing acid treatment jobs. The key idea of this model is to use a power law permeability function that varies with the radial distance from well bore. Scaling exponent of this power law function has been named power law index. The permeability function has also been termed as secondary permeability. This work introduces the method of Laplace solution to solve the problem of transient and pseudo steady-state flow in a fracture network. Development and validation of this method and its extension to predict the pressure (and production) behaviour of fracture network were made using a novel technic. Pressure solution was then combined with material balance through productivity index to make production forecast. Reservoir rock volume affected by the fracture stimulation treatment that contributes in the production is called effective stimulated volume. This represents the extent of fracture network in this case. Barnett shale formation is a naturally fractured shale reservoir in Fort Worth basin. Several production wells from this formation was analysed using Power Law Model and it was found that wells productivity are highly dependent on stimulated volume. Apparently the wells flow under pseudo steady state for most part of their producing life and the effect of boundary on production is evident in as soon as one months of production. Due to short period of transient flow production from Barnett formations is expected to be largely independent of the relative distribution of permeability and highly dependent on the stimulated area and induced secondary permeability. However, an indirect relationship between permeability distribution and production rate is observed. A well with low power law index shows a better (more even) secondary permeability distribution in spatial direction, larger stimulated volume and better production. A comparative analysis between the new model and traditional fracture model was made. It was found that both models can be used successfully for history matching and production forecasting from hydraulically fractured shale gas formation.

Kumar, Amrendra

2008-12-01T23:59:59.000Z

140

Fracturing operations in a dry geothermal reservoir  

DOE Green Energy (OSTI)

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

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

1983-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "natural fracture detection" 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

Fracturing fluids -- then and now  

Science Conference Proceedings (OSTI)

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

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

1996-07-01T23:59:59.000Z

142

Suspensions in hydraulic fracturing  

Science Conference Proceedings (OSTI)

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

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

1996-12-31T23:59:59.000Z

143

HYDRAULIC FRACTURING AND INDUCED SEISMICITY IN KANSAS  

E-Print Network (OSTI)

For some time the public has asked questions about seismic activity related to hydraulic fracturing and other oil-field related activities. In particular, there is concern that the energy that goes into the subsurface during hydraulic fracturing is sufficient to cause felt earthquakes. The following is a response to those questions. 1) Seismic activity that is related to human activities is generally referred to as “induced seismicity ” or “triggered seismicity. ” Induced seismicity is defined as “seismic events attributable to human activities ” (National Research Council, 2012). The term “triggered seismicity ” is also used to describe situations in which human activities “could potentially ‘trigger ’ large and potentially damaging earthquakes ” (Shemeta et al., 2012). The following discussion uses only the term “induced seismicity ” to refer to seismic activity in which human activity plays a role. 2) Because it uses energy to fracture rocks to release oil or natural gas, hydraulic fracturing does create microseismic events (of a magnitude less than 2.0). Felt earthquake activity (generally greater than a magnitude 3.0) resulting from hydraulic fracturing has been confirmed from only one location in the world (National Research Council, 2012). In the

unknown authors

2013-01-01T23:59:59.000Z

144

Relative permeability through fractures  

DOE Green Energy (OSTI)

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

Diomampo, Gracel, P.

2001-08-01T23:59:59.000Z

145

FRACTURING FLUID CHARACTERIZATION FACILITY  

SciTech Connect

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

Subhash Shah

2000-08-01T23:59:59.000Z

146

Water infiltration and intermittent flow in rough-walled fractures  

DOE Green Energy (OSTI)

Flow visualization experiments were conducted in transparent replicas of natural rough-walled fractures. The fracture was inclined to observe the interplay between capillary and gravity forces. Water was introduced into the fracture by a capillary siphon. Preferential flow paths were observed, where intermittent flow frequently occurred. The water infiltration experiments suggest that intermittent flow in fractures appears to be the rule rather than the exception. In order to investigate the mechanism causing intermittent flow in fractures, parallel plates with different apertures were assembled using lucite and glass. A medium-coarse-fine pore structure is believed to cause the intermittency in flow. Intermittent flow was successfully produced in the parallel plate experiments using the lucite plates. After several trials, intermittent flow was also produced in the glass plates.

Su, G.

1995-05-01T23:59:59.000Z

147

On relative permeability of rough-walled fractures  

DOE Green Energy (OSTI)

This paper presents a conceptual and numerical model of multiphase flow in fractures. The void space of real rough-walled rock fractures is conceptualized as a two-dimensional heterogeneous porous medium, characterized by aperture as a function of position in the fracture plane. Portions of a fracture are occupied by wetting and non-wetting phase, respectively, according to local capillary pressure and accessibility criteria. Phase occupancy and permeability are derived by assuming a parallel-plate approximation for suitably small subregions in the fracture plane. Wetting and non-wetting phase relative permeabilities are calculated by numerically simulating single phase flows separately in the wetted and non-wetted pore spaces. Illustrative examples indicate that relative permeabilities depend sensitively on the nature and range of spatial correlation between apertures. 30 refs., 7 figs., 1 tab.

Pruess, K.; Tsang, Y.W.

1989-01-01T23:59:59.000Z

148

Selection of fracture fluid for stimulating tight gas reservoirs  

E-Print Network (OSTI)

Essentially all producing wells drilled in tight gas sands and shales are stimulated using hydraulic fracture treatments. The development of optimal fracturing procedures, therefore, has a large impact on the long-term economic viability of the wells. The industry has been working on stimulation technology for more than 50 years, yet practices that are currently used may not always be optimum. Using information from the petroleum engineering literature, numerical and analytical simulators, surveys from fracturing experts, and statistical analysis of production data, this research provides guidelines for selection of the appropriate stimulation treatment fluid in most gas shale and tight gas reservoirs. This study takes into account various parameters such as the type of formation, the presence of natural fractures, reservoir properties, economics, and the experience of experts we have surveyed. This work provides a guide to operators concerning the selection of an appropriate type of fracture fluid for a specific set of conditions for a tight gas reservoir.

Malpani, Rajgopal Vijaykumar

2006-12-01T23:59:59.000Z

149

Geomechanical Development of Fractured Reservoirs During Gas Production  

E-Print Network (OSTI)

Within fractured reservoirs, such as tight gas reservoir, coupled processes between matrix deformation and fluid flow are very important for predicting reservoir behavior, pore pressure evolution and fracture closure. To study the coupling between gas desorption and rock matrix/fracture deformation, a poroelastic constitutive relation is developed and used for deformation of gas shale. Local continuity equation of dry gas model is developed by considering the mass conservation of gas, including both free and absorbed phases. The absorbed gas content and the sorption-induced volumetric strain are described through a Langmiur-type equation. A general porosity model that differs from other empirical correlations in the literature is developed and utilized in a finite element model to coupled gas diffusion and rock mass deformation. The dual permeability method (DPM) is implemented into the Finite Element Model (FEM) to investigate fracture deformation and closure and its impact on gas flow in naturally fractured reservoir. Within the framework of DPM, the fractured reservoir is treated as dual continuum. Two independent but overlapping meshes (or elements) are used to represent these kinds of reservoirs: one is the matrix elements used for deformation and fluid flow within matrix domain; while the other is the fracture element simulating the fluid flow only through the fractures. Both matrix and fractures are assumed to be permeable and can accomodate fluid transported. A quasi steady-state function is used to quantify the flow that is transferred between rock mass and fractures. By implementing the idea of equivalent fracture permeability and shape-factor within the transfer function into DPM, the fracture geometry and orientation are numerically considered and the complexity of the problem is well reduced. Both the normal deformation and shear dilation of fractures are considered and the stress-dependent fracture aperture can be updated in time. Further, a non-linear numerical model is constructed by implementing a poroviscoelastic model into the dual permeability (DPM)-finite element model (FEM) to investigate the coupled time-dependent viscoelastic deformation, fracture network evolution and compressible fluid flow in gas shale reservoir. The viscoelastic effect is addressed in both deviatoric and symmetric effective stresses to emphasize the effect of shear strain localization on fracture shear dilation. The new mechanical model is first verified with an analytical solution in a simple wellbore creep problem and then compared with the poroelastic solution in both wellbore and field cases.

Huang, Jian

2013-05-01T23:59:59.000Z

150

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

151

Self-potential observations during hydraulic fracturing  

E-Print Network (OSTI)

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

Moore, Jeffrey R.; Glaser, Steven D.

2008-01-01T23:59:59.000Z

152

Hydraulic Fracturing Poster | Department of Energy  

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

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

153

DigiFract: A software and data model implementation for flexible acquisition and processing of fracture data from outcrops  

Science Conference Proceedings (OSTI)

This paper presents the development and use of our new DigiFract software designed for acquiring fracture data from outcrops more efficiently and more completely than done with other methods. Fracture surveys often aim at measuring spatial information ... Keywords: Customizing GIS, Data model and spatial analyses, Geologic field acquisition, Natural fracture description

N. J. Hardebol, G. Bertotti

2013-04-01T23:59:59.000Z

154

Using Chemicals to Optimize Conformance Control in Fractured Reservoirs  

SciTech Connect

This report describes work performed during the third and final year of the project, Using Chemicals to Optimize Conformance Control in Fractured Reservoirs. This research project had three objectives. The first objective was to develop a capability to predict and optimize the ability of gels to reduce permeability to water more than that to oil or gas. The second objective was to develop procedures for optimizing blocking agent placement in wells where hydraulic fractures cause channeling problems. The third objective was to develop procedures to optimize blocking agent placement in naturally fractured reservoirs.

Seright, Randall S.; Liang, Jenn-Tai; Schrader, Richard; Hagstrom II, John; Wang, Ying; Kumar, Ananad; Wavrik, Kathryn

2001-10-29T23:59:59.000Z

155

Using Chemicals to Optimize Conformance Control in Fractured Reservoirs  

SciTech Connect

The objectives of this project are: (1) to develop a capability to predict and optimize the ability of gels to reduce permeability to water more than that to oil or gas, (2) to develop procedures for optimizing blocking agent placement in wells where hydraulic fractures cause channeling problems, and (3) to develop procedures to optimize blocking agent placement in naturally fractured reservoirs. Work was directed at both injection wells and production wells and at vertical, horizontal, and highly deviated wells.

Seright, Randall; Liang, Jenn-Tai; Schrader, Richard; Hagstrom II, John; Wang, Ying; Kumar, Anand; Wavrik, Kathryn

2001-09-07T23:59:59.000Z

156

TEMPORAL VARIATIONS OF FRACTURE DIRECTIONS AND FRACTURE DENSITIES IN THE  

Open Energy Info (EERE)

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

157

Breakthrough in fracture mechanics  

SciTech Connect

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

Lihach, N.

1981-05-01T23:59:59.000Z

158

Fracture characterization of multilayered reservoirs  

Science Conference Proceedings (OSTI)

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

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

1986-01-01T23:59:59.000Z

159

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

SciTech Connect

Geothermal energy is recovered by circulating water through heat exchange areas within a hot rock mass. Geothermal reservoir rock masses generally consist of igneous and metamorphic rocks that have low matrix permeability. Therefore, cracks and fractures play a significant role in extraction of geothermal energy by providing the major pathways for fluid flow and heat exchange. Therefore, knowledge of the conditions leading to formation of fractures and fracture networks is of paramount importance. Furthermore, in the absence of natural fractures or adequate connectivity, artificial fractures are created in the reservoir using hydraulic fracturing. Multiple fractures are preferred because of the large size necessary when using only a single fracture. Although the basic idea is rather simple, hydraulic fracturing is a complex process involving interactions of high pressure fluid injections with a stressed hot rock mass, mechanical interaction of induced fractures with existing natural fractures, and the spatial and temporal variations of in-situ stress. As a result, it is necessary to develop tools that can be used to study these interactions as an integral part of a comprehensive approach to geothermal reservoir development, particularly enhanced geothermal systems. In response to this need we have developed advanced poro-thermo-chemo-mechanical fracture models for rock fracture research in support of EGS design. The fracture propagation models are based on a regular displacement discontinuity formulation. The fracture propagation studies include modeling interaction of induced fractures. In addition to the fracture propagation studies, two-dimensional solution algorithms have been developed and used to estimate the impact of pro-thermo-chemical processes on fracture permeability and reservoir pressure. Fracture permeability variation is studied using a coupled thermo-chemical model with quartz reaction kinetics. The model is applied to study quartz precipitation/dissolution, as well as the variation in fracture aperture and pressure. Also, a three-dimensional model of injection/extraction has been developed to consider the impact poro- and thermoelastic stresses on fracture slip and injection pressure. These investigations shed light on the processes involved in the observed phenomenon of injection pressure variation (e.g., in Coso), and allow the assessment of the potential of thermal and chemical stimulation strategies.

Ahmad Ghassemi

2009-10-01T23:59:59.000Z

160

Laboratory Evaluation of an Electrochemical Noise System for Detection of Localized and General Corrosion of Natural Gas Transmission Pipelines  

SciTech Connect

Gas transmission pipelines are susceptible to both internal (gas side) and external (soil side) corrosion attack. Internal corrosion is caused by the presence of salt laden moisture, CO{sub 2}, H{sub 2}S, and perhaps O{sub 2} in the natural gas. Internal corrosion usually manifests itself as general corrosion. However, the presence of chlorides in entrained water also can lead to pitting corrosion damage. The electrochemical noise technique can differentiate general from localized corrosion and provide estimates of corrosion rates without external perturbation of the corroding system. It is increasingly being applied to field and industrial installations for in situ corrosion monitoring. It has been used here to determine its suitability for monitoring internal and external corrosion damage on gas transmission pipelines. Corrosion measurements were made in three types of environments: (1) aqueous solutions typical of those found within gas pipelines in equilibrium with th e corrosive components of natural gas; (2) biologically-active soils typical of wetlands; and (3) a simulated, unpressurized, internal gas/liquid gas pipeline environment. Multiple sensor designs were evaluated in the simulated pipe environment. Gravimetric measurements were conducted in parallel with the electrochemical noise measurements to validate the results.

Bullard, S.J.; Covino, B.S., Jr.; Russell, J.H.; Holcomb, G.R.; Cramer, S.D.; Ziomek-Moroz, M.; Eden, D.

2003-03-16T23:59:59.000Z

Note: This page contains sample records for the topic "natural fracture detection" 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

Rigid Body Simulation with Local Fracturing Effects  

Science Conference Proceedings (OSTI)

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

Wu Bo; Zeng Liang; Wu Yagang

2011-05-01T23:59:59.000Z

162

Comparison of pressure ransient response in intensely and sparsely fractured reservoirs  

DOE Green Energy (OSTI)

A comprehensive analytical model is presented to study the pressure transient behavior of a naturally fractured reservoir with a continuous matrix block size distribution. Geologically realistic probability density functions of matrix block size are used to represent reservoirs of varying fracture intensity and uniformity. Transient interporosity flow is assumed and interporosity skin is incorporated. Drawdown and interference pressure transient tests are investigated. The results show distinctions in the pressure response from intensely and sparsely fractured reservoirs in the absence of interporosity skin. Also, uniformly and nonuniformly fractured reservoirs exhibit distinct responses, irrespective of the degree of fracture intensity. The pressure response in a nonuniformly fractured reservoir with large block size variability, approaches a nonfractured (homogeneous) reservoir response. Type curves are developed to estimate matrix block size variability and the degree of fracture intensity from drawdown and interference well tests.

Johns, R.T.

1989-01-01T23:59:59.000Z

163

Comparison of pressure transient response in intensely and sparsely fractured reservoirs  

DOE Green Energy (OSTI)

A comprehensive analytical model is presented to study the pressure transient behavior of a naturally fractured reservoir with a continuous matrix block size distribution. Geologically realistic probability density functions of matrix block size are used to represent reservoirs of varying fracture intensity and uniformity. Transient interporosity flow is assumed and interporosity skin is incorporated. Drawdown and interference pressure transient tests are investigated. The results show distinctions in the pressure response from intensely and sparsely fractured reservoirs in the absence of interporosity skin. Also, uniformly and nonuniformly fractured reservoirs exhibit distinct responses, irrespective of the degree of fracture intensity. The pressure response in a nonuniformly fractured reservoir with large block size variability, approaches a nonfractured (homogeneous) reservoir response. Type curves are developed to estimate matrix block size variability and the degree of fracture intensity from drawdown and interference well tests.

Johns, R.T.

1989-04-01T23:59:59.000Z

164

Real-time and post-frac' 3-D analysis of hydraulic fracture treatments in geothermal reservoirs  

SciTech Connect

Economic power production from Hot Dry Rock (HDR) requires the establishment of an efficient circulation system between wellbores in reservoir rock with extremely low matrix permeability. Hydraulic fracturing is employed to establish the necessary circulation system. Hydraulic fracturing has also been performed to increase production from hydrothermal reservoirs by enhancing the communication with the reservoir's natural fracture system. Optimal implementation of these hydraulic fracturing applications, as with any engineering application, requires the use of credible physical models and the reconciliation of the physical models with treatment data gathered in the field. Analysis of the collected data has shown that 2-D models and 'conventional' 3-D models of the hydraulic fracturing process apply very poorly to hydraulic fracturing in geothermal reservoirs. Engineering decisions based on these more 'conventional' fracture modeling techniques lead to serious errors in predicting the performance of hydraulic fracture treatments. These errors can lead to inappropriate fracture treatment design as well as grave errors in well placement for hydrothermal reservoirs or HDR reservoirs. This paper outlines the reasons why conventional modeling approaches fall short, and what types of physical models are needed to credibly estimate created hydraulic fracture geometry. The methodology of analyzing actual measured fracture treatment data and matching the observed net fracturing pressure (in realtime as well as after the treatment) is demonstrated at two separate field sites. Results from an extensive Acoustic Emission (AE) fracture diagnostic survey are also presented for the first case study aS an independent measure of the actual created hydraulic fracture geometry.

Wright, C.A.; Tanigawa, J.J.; Hyodo, Masami; Takasugi, Shinji

1994-01-20T23:59:59.000Z

165

Simulation studies to evaluate the effect of fracture closure on the performance of fractured reservoirs; Final report  

SciTech Connect

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 overall objectives of the study were to: (1) evaluate the reservoir conditions for which fracture closure is significant, and (2) evaluate innovative fluid injection techniques capable of maintaining pressure within the reservoir. The evaluations of reservoir performance were made by a modern dual porosity simulator, TETRAD. This simulator treats both porosity and permeability as functions of pore pressure. The Austin Chalk in the Pearsall Field in of South Texas was selected as the prototype fractured reservoir for this work. During the first year, simulations of vertical and horizontal well performance were made assuming that fracture permeability was insensitive to pressure change. Sensitivity runs indicated that the simulator was predicting the effects of critical reservoir parameters in a logical and consistent manner. The results confirmed that horizontal wells could increase both rate of oil recovery and total oil recovery from naturally fractured reservoirs. In the second year, the performance of the same vertical and horizontal wells was reevaluated with fracture permeability treated as a function of reservoir pressure. To investigate sensitivity to in situ stress, differing loading conditions were assumed. Simulated natural depletions confirm that pressure sensitive fractures degrade well performance. The severity of degradation worsens when the initial reservoir pressure approaches the average stress condition of the reservoir, such as occurs in over pressured reservoirs. Simulations with water injection indicate that degradation of permeability can be counteracted when reservoir pressure is maintained and oil recovery can be increased when reservoir properties are favorable.

Howrie, I.; Dauben, D.

1994-03-01T23:59:59.000Z

166

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

E-Print Network (OSTI)

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

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

2004-01-01T23:59:59.000Z

167

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

E-Print Network (OSTI)

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

Wu, Yu-Shu; Pruess, Karsten

2004-01-01T23:59:59.000Z

168

Simulation on Discrete Fracture Network Using Flexible Voronoi Gridding  

E-Print Network (OSTI)

Fractured reservoirs are generally simulated using Warren and Root26 dual-porosity (DP) approach. The main assumption of this approach is that the geometry of fractures are uniformly distributed and interconnected in reservoirs. This may be true for many cases of naturally fractured reservoirs. However, for a large scale and disconnected fractured reservoirs, DP is often not applicable. Due to the latter case, it is necessary to have more sophisticated simulation studies which allow the fracture to be geometry explicitly represented into the static model using Discrete Fracture Network (DFN) approach. Most work on DFN grid model up to recently has been done with Delaunay tessellations. This research proposes an alternative technique to discretize the two-dimensional DFN using Voronoi diagrams, nevertheless applying the same DFN principles outlined in previous work. Through complicated procedures to generate DFN model, grid system based on Voronoi polygons has been developed. The procedure will force Voronoi edges follow the exact geometry of fractures. Furthermore, implementing the Voronoi diagrams allows the use of fewer polygons than the traditional Local Grid Refinement (LGR). And most importantly, due to the nature of the Voronoi polygons or locally orthogonal grids, the transmissibility calculations can be simplified and are more accurate than corner point formulation for non-square grid blocks. Finally, the main and most important goal of this study is to develop a black-oil Control Volume Finite Difference (CVFD) reservoir simulator that allows us to model DFN more realistically. One of the features of the developed simulator is the capability to model individual fractures with non-uniform aperture distribution, such as log-normally distributed apertures as shown using X-Ray CT scanner measurements. Prior to using the DFN simulator to model reservoirs with fractures and their apertures distribution, the simulator was validated against commercial simulators. The simulator provides results in close agreement with those of a reference finite-difference simulator in cases where direct comparisons are possible. Several simulations of synthetic DFN were presented to demonstrate the robustness of the Voronoi diagrams to represent fracture networks and its aperture distributions. In summary, the simulation of the DFN using the proposed approaches is capable to model both fractured and unfractured systems. However, the DFN model with Voronoi grids requires more efforts on building the grid model compared to other methods. Numerically, simulations of fractured systems are very challenging.

Syihab, Zuher

2009-12-01T23:59:59.000Z

169

Hydraulic Fracturing Data Collection Tools Improve Environmental Reporting,  

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

Hydraulic Fracturing Data Collection Tools Improve Environmental Hydraulic Fracturing Data Collection Tools Improve Environmental Reporting, Monitoring, Protection Hydraulic Fracturing Data Collection Tools Improve Environmental Reporting, Monitoring, Protection April 18, 2013 - 12:03pm Addthis Washington, DC -Two data collection tools specifically developed for hydraulic fracturing are available to help regulatory agencies monitor drilling and completion operations and enhance environmental protection. Developed with support from the U.S. Department of Energy's Office of Fossil Energy (FE), the Risk Based Data Management System (RBDMS) and FracFocus chemical disclosure registry provide a way for industry professionals, regulatory agencies and the general public to more easily access information on oil and natural gas activities. These reporting and

170

Evaluation of subsurface fracture geometry using fluid pressure response to  

Open Energy Info (EERE)

subsurface fracture geometry using fluid pressure response to subsurface fracture geometry using fluid pressure response to solid earth tidal strain Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Report: Evaluation of subsurface fracture geometry using fluid pressure response to solid earth tidal strain Details Activities (1) Areas (1) Regions (0) Abstract: The nature of solid earth tidal strain and surface load deformation due to the influence of gravitational forces and barometric pressure loading are discussed. The pore pressure response to these types of deformation is investigated in detail, including the cases of a confined aquifer intersected by a well and a discrete fracture intersected by a well. The integration of the tidal response method with conventional pump tests in order to independently calculate the hydraulic parameters of the

171

Hydraulic Fracturing Data Collection Tools Improve Environmental Reporting,  

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

Hydraulic Fracturing Data Collection Tools Improve Environmental Hydraulic Fracturing Data Collection Tools Improve Environmental Reporting, Monitoring, Protection Hydraulic Fracturing Data Collection Tools Improve Environmental Reporting, Monitoring, Protection April 18, 2013 - 12:03pm Addthis Washington, DC -Two data collection tools specifically developed for hydraulic fracturing are available to help regulatory agencies monitor drilling and completion operations and enhance environmental protection. Developed with support from the U.S. Department of Energy's Office of Fossil Energy (FE), the Risk Based Data Management System (RBDMS) and FracFocus chemical disclosure registry provide a way for industry professionals, regulatory agencies and the general public to more easily access information on oil and natural gas activities. These reporting and

172

Two-phase flow visualization and relative permeability measurement in transparent replicas of rough-walled rock fractures  

DOE Green Energy (OSTI)

Understanding and quantifying multi-phase flow in fractures is important for mathematical and numerical simulation of geothermal reservoirs, nuclear waste repositories, and petroleum reservoirs. While the cubic law for single-phase flow has been well established for parallel-plate fractures theoretically and experimentally, no reliable measurements of multi-phase flow in fractures have been reported. This work reports the design and fabrication of an apparatus for visualization of two-phase flow and for measurement of gas-liquid relative permeability in realistic rough-walled rock fractures. A transparent replica of a natural rock fracture from a core specimen is fabricated by molding and casting in clear epoxy. Simultaneous flow of gas and liquid with control of capillary pressure at inlet and outlet is achieved with the Hassler sandwich'' design: liquid is injected to the fracture through a porous block, while gas is injected directly to the edge of the fracture through channels in the porous block. A similar arrangement maintains capillary separation of the two phases at the outlet. Pressure drops in each phase across the fracture, and capillary pressures at the inlet and outlet, are controlled by means of pumps and needle valves, and are measured by differential and absolute pressure transducers. The clear epoxy cast of the natural fracture preserves the geometry of the fracture and permits visual observation of phase distributions. The fracture aperture distribution can be estimated by filling the fracture with a dyed liquid, and making pointwise measurements of the intensity of transmitted light.

Persoff, P.; Pruess, K.; Myer, L.

1991-01-01T23:59:59.000Z

173

Page 1 of 5 Narrative Description of Hydraulic Fracturing Draft Regulations  

E-Print Network (OSTI)

. California oil and natural gas is almost always associated with "produced water" ­ that is, brackish water, making separation of the fracturing fluids from the produced water impossible. The fracturing fluid is then co- disposed with the produced water. Current regulations specify the disposal requirements

174

Utilisation of seismic and resistivity data for fracture characterisation and simulation  

Science Conference Proceedings (OSTI)

Characterisation of the heterogeneous naturally fractured reservoirs is an essential and significantly challenging task, especially due to the limited data availability. This paper presents a foundation relationship between P-wave / S-wave velocity and ... Keywords: artificial neural network, controlled source electromagnetic surveying, discrete fracture network, electromagnetic, seismic

Nam H. Tran; Amna Ali; Abdul Ravoof; Nam Nguyen

2007-05-01T23:59:59.000Z

175

Location of hydraulic fractures using microseismic techniques  

DOE Green Energy (OSTI)

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

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

1980-01-01T23:59:59.000Z

176

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

177

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

E-Print Network (OSTI)

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

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

2000-01-01T23:59:59.000Z

178

The use of air as a natural tracer infractured hydrothermal systems, Los Azufres, Mexico, case study  

DOE Green Energy (OSTI)

Injection of atmospheric air mixed with cold water has been occurring since 1982 at the Los Azufres geothermal field. Several chemical and thermodynamical evidences show that air injection into this fractured hydrothermal system could be considered as a long term natural tracer test. Nitrogen and Argon separated from the air mixture migrate, under the action of the induced injection-extraction gradient, from reinjection sectors to production zones following preferential paths closely related to high permeability conduits. A coarse numerical estimation of the average permeability tensor existing at Tejamaniles, the southern sector, explains the unsuccessful recovery of the artificial tracer tests performed in past years: the anisotropic nature of the fractured volcanic rock would demand considerably quantities of tracer in order to be detected at the producing wells, especially when fluid extraction was low. At the same time concentrations of calcium, cesium, chloride, potassium, rubidium and sodium, are increasing in the liquid produced by the oldest wells of this field's sector.

Mario Cesar Sudrez Arriaga; Hector Gutierrez Puente, Josefina Moreno Ochoa

1991-01-01T23:59:59.000Z

179

Practical simulation of hierarchical brittle fracture  

Science Conference Proceedings (OSTI)

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

Seungtaik Oh; Seunghyup Shin; Hyeryeong Jun

2012-05-01T23:59:59.000Z

180

Results from a discrete fracture network model of a Hot Dry Rock system  

Science Conference Proceedings (OSTI)

The work described represents a move towards better representations of the natural fracture system. The discrete fracture network model used during the study was the NAPSAC code (Grindrod et al, 1992). The goals of the work were to investigate the application of discrete fracture network models to Hot Dry Rock systems, increase the understanding of the basic thermal extraction process and more specifically the understanding of the Rosemanowes Phase 2B system. The aim in applying the work to the Rosemanowes site was to use the discrete fracture network approach to integrate a diverse set of field measurements into as simple a model as possible.

Lanyon, G.W.; Batchelor, A.S.; Ledingham, P.

1993-01-28T23:59:59.000Z

Note: This page contains sample records for the topic "natural fracture detection" 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

DOE's Shale Gas and Hydraulic Fracturing Research | Department of Energy  

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

Shale Gas and Hydraulic Fracturing Research Shale Gas and Hydraulic Fracturing Research DOE's Shale Gas and Hydraulic Fracturing Research April 26, 2013 - 11:05am Addthis Statement of Guido DeHoratiis Acting Deputy Assistant Secretary for Oil and Natural Gas before the House Committee on Science, Space, and Technology Subcommittees on Energy and Environment. I want to thank the Chairs, Ranking Members and Members of the Subcommittees for inviting me to appear before you today to discuss the critical role that the Department of Energy's Office of Fossil Energy, in collaboration with the Department of the Interior (DOI) and the Environmental Protection Agency (EPA), is playing to improve the safety and environmental performance of developing our Nation's unconventional oil and natural gas (UOG) resources.

182

Wormhole formation in dissolving fractures  

E-Print Network (OSTI)

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

Szymczak, P

2009-01-01T23:59:59.000Z

183

Flow dynamics and solute transport in unsaturated rock fractures  

DOE Green Energy (OSTI)

Rock fractures play an important role in flow and contaminant transport in fractured aquifers, production of oil from petroleum reservoirs, and steam generation from geothermal reservoirs. In this dissertation, phenomenological aspects of flow in unsaturated fractures were studied in visualization experiments conducted on a transparent replica of a natural, rough-walled rock fracture for inlet conditions of constant pressure and flow rate over a range of angles of inclination. The experiments demonstrated that infiltrating liquid proceeds through unsaturated rock fractures along non-uniform, localized preferential flow paths. Even in the presence of constant boundary conditions, intermittent flow was a persistent flow feature observed, where portions of the flow channel underwent cycles of snapping and reforming. Two modes of intermittent flow were observed, the pulsating blob mode and the rivulet snapping mode. A conceptual model for the rivulet snapping mode was proposed and examined using idealized, variable-aperture fractures. The frequency of intermittent flow events was measured in several experiments and related to the capillary and Bond numbers to characterize this flow behavior.

Su, G. W.

1999-10-01T23:59:59.000Z

184

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

E-Print Network (OSTI)

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

Fletcher, Sarah Marie

2012-01-01T23:59:59.000Z

185

IN SITU STRESS, FRACTURE AND FLUID FLOW ANALYSIS-EAST FLANK OF...  

Open Energy Info (EERE)

here are from the first year of a five year project and include the discrimination of natural from drilling-induced fractures in wellbore image data in the four study wells,...

186

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

Science Conference Proceedings (OSTI)

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

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

1993-01-01T23:59:59.000Z

187

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.

188

Meshless animation of fracturing solids  

Science Conference Proceedings (OSTI)

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

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

2005-07-01T23:59:59.000Z

189

NETL: Discrete Fracture Reservoir Simulation Software  

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

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

190

Self-potential observations during hydraulic fracturing  

E-Print Network (OSTI)

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

Moore, J R; Glaser, Steven D

2007-01-01T23:59:59.000Z

191

Some Fundamental Mechanisms of Hydraulic Fracturing .  

E-Print Network (OSTI)

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

Wu, Ruiting

2006-01-01T23:59:59.000Z

192

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

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

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

193

“Hanging” Pelvic Gallbladder Simulating Occult Hip Fracture Versus Appendicitis  

E-Print Network (OSTI)

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

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

2010-01-01T23:59:59.000Z

194

Fracture and Healing of Rock Salt Related to Salt Caverns  

Science Conference Proceedings (OSTI)

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

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

1999-03-01T23:59:59.000Z

195

Lisburne Formation fracture characterization and flow modeling  

E-Print Network (OSTI)

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

Karpov, Alexandre Valerievich

2001-01-01T23:59:59.000Z

196

Fracture patterns in graywacke outcrops at The Geysers geothermal field  

DOE Green Energy (OSTI)

The Geysers geothermal field covers an area of more than 35,000 acres and represents one of the most significant steam fields in the world. The heterogeneous nature of the reservoir, its fracture network and non-sedimentary rock distinguish it from ordinary sandstone reservoirs in terms of reservoir definition and evaluation (Stockton et al. 1984). Analysis of cuttings, record of steam entries, temperature and pressure surveys and spinner logs have contributed to an understanding of the subsurface geology and rock characteristics of the Geysers. Few conventional electrical log data are available for the main body of the reservoir. It is generally believed that while the fractures are the main conducts for fluid transport through the reservoirs, tight rocks between the major fractures contain the bulk of the fluid reserves. No independent measurement of liquid and vapor saturation can be made from the existing downhole tools. Pressure depletion in The Geysers geothermal field has become a major concern to the operators and utility companies in recent years. Plans for further development activities and future field management are contingent upon accurate computer modeling and definition of the field. The primary issues in reliable characterization of The Geysers field are the role of the rock matrix in holding liquid reserves and providing pressure support, the nature of fracture network, extent of liquid saturation in the reservoirs and injection pattern strategies to maximize heat recovery. Current modeling of The Geysers field is done through the use of general purpose geothermal reservoir simulators. Approaches employed include treating the reservoir as a single porosity equivalent or a dual porosity system. These simulators include formulation to represent transport of heat, steam and water. Heterogeneities are represented by spatial variations in formation or fracture permeability-thickness product, porosity or fluid saturations. Conceptual models based on dual porosity representations have been shown to duplicate the history. Prediction of future performance is, however, not reliable because of uncertainties in assumptions of the initial state of the reservoir, Specifically, several different initial state conditions have led to a fairly good match of the historical data. Selection of the exact initial conditions is a major dilemma. In dual porosity models, the complex nature of fracture network is formulated by a systematic, well-organized set of orthogonal fractures. Also, the exact nature of matrix-fracture interaction, and the role of adsorption and capillarity in pressure support are not well-defined.

Sammis, Charles G.; Lin Ji An; Ershaghi, I.

1991-01-01T23:59:59.000Z

197

Fracturing Fluid Characterization Facility  

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

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

198

Explosive fracturing method  

SciTech Connect

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

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

1973-12-11T23:59:59.000Z

199

Discrete element modeling of rock deformation, fracture network development and permeability evolution under hydraulic stimulation  

SciTech Connect

Key challenges associated with the EGS reservoir development include the ability to reliably predict hydraulic fracturing and the deformation of natural fractures as well as estimating permeability evolution of the fracture network with time. We have developed a physics-based rock deformation and fracture propagation simulator by coupling a discrete element model (DEM) for fracturing with a network flow model. In DEM model, solid rock is represented by a network of discrete elements (often referred as particles) connected by various types of mechanical bonds such as springs, elastic beams or bonds that have more complex properties (such as stress-dependent elastic constants). Fracturing is represented explicitly as broken bonds (microcracks), which form and coalesce into macroscopic fractures when external and internal load is applied. The natural fractures are represented by a series of connected line segments. Mechanical bonds that intersect with such line segments are removed from the DEM model. A network flow model using conjugate lattice to the DEM network is developed and coupled with the DEM. The fluid pressure gradient exerts forces on individual elements of the DEM network, which therefore deforms the mechanical bonds and breaks them if the deformation reaches a prescribed threshold value. Such deformation/fracturing in turn changes the permeability of the flow network, which again changes the evolution of fluid pressure, intimately coupling the two processes. The intimate coupling between fracturing/deformation of fracture networks and fluid flow makes the meso-scale DEM- network flow simulations necessary in order to accurately evaluate the permeability evolution, as these methods have substantial advantages over conventional continuum mechanical models of elastic rock deformation. The challenges that must be overcome to simulate EGS reservoir stimulation, preliminary results, progress to date and near future research directions and opportunities will be discussed. Methodology for coupling the DEM model with continuum flow and heat transport models will also be discussed.

Shouchun Deng; Robert Podgorney; Hai Huang

2011-02-01T23:59:59.000Z

200

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

Science Conference Proceedings (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

Note: This page contains sample records for the topic "natural fracture detection" 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

Using Chemicals to Optimize Conformance Control in Fractured Reservoirs  

SciTech Connect

This report describes work performed during the first year of the project, ''Using Chemicals to Optimize Conformance Control in Fractured Reservoirs.'' This research project has three objectives. The first objective is to develop a capability to predict and optimize the ability of gels to reduce permeability to water more than that to oil or gas. The second objective is to develop procedures for optimizing blocking agent placement in wells where hydraulic fractures cause channeling problems. The third objective is to develop procedures to optimize blocking agent placement in naturally fractured reservoirs. This research project consists of three tasks, each of which addresses one of the above objectives. Our work is directed at both injection wells and production wells and at vertical, horizontal, and highly deviated wells.

Seright, Randall S.; Liang, Jenn-Tai; Schrader, Richard; Hagstrom II, John; Liu, Jin; Wavrik, Kathryn

1999-09-27T23:59:59.000Z

202

NATURAL GAS FROM SHALE: Questions and Answers Shale Gas Development Challenges -  

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

Fracture Fluids Fracture Fluids Key Points: * Shale fracture fluid, or "slickwater," is largely composed of water (99%); but a number of additives are mixed in with it to increase the effectiveness of the fracturing operation. These additives vary as a function of the well type and the preferences of the operator. * Hydraulic fracturing fluids can contain hazardous chemicals and, if mismanaged, spills could leak harmful substances into ground or surface water. However, good field practice, governed by existing regulations, "should provide an adequate level of protection" from fracturing fluid risks. 1 1 Massachusetts Institute of Technology, "MIT Study on the Future of Natural Gas," June 6, 2011, Chapter 2: Supply, page 41.

203

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

E-Print Network (OSTI)

In the coming decades, the world will require additional supplies of natural gas to meet the demand for energy. Tight gas reservoirs can be defined as reservoirs where the formation permeability is so low (flowback procedures, production strategy, and reservoir conditions. Residual polymer in the fracture can reduce the effective fracture permeability and porosity, reduce the effective fracture half-length, and limit the well productivity. Our ability to mathematically model the fundamental physical processes governing fluid recovery in hydraulic fractures in the past has been limited. In this research, fracture fluid damage mechanisms have been investigated, and mathematical models and computer codes have been developed to better characterize the cleanup process. The codes have been linked to a 3D, 3-phase simulator to model and quantify the fracture fluid cleanup process and its effect on long-term gas production performances. Then, a comprehensive systematic simulation study has been carried out by varying formation permeability, reservoir pressure, fracture length, fracture conductivity, yield stress, and pressure drawdown. On the basis of simulation results and analyses, new ways to improve fracture fluid cleanup have been provided. This new progress help engineers better understand fracture fluid cleanup, improve fracture treatment design, and increase gas recovery from tight sand reservoirs, which can be extremely important as more tight gas reservoirs are developed around the world.

Wang, Yilin

2008-12-01T23:59:59.000Z

204

Vertical arrays for fracture mapping in geothermal systems  

DOE Green Energy (OSTI)

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

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

1998-12-01T23:59:59.000Z

205

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

206

Foam flow through a transparent rough-walled rock fracture  

SciTech Connect

This paper presents an experimental study of nitrogen, water, and aqueous foam flow through a transparent replica of a natural rough-walled rock fracture with a hydraulic aperture of roughly 30 {mu}m. It is established that single-phase flow of both nitrogen and water is well described by analogy to flow between parallel plates. Inertial effects caused by fracture roughness become important in single-phase flow as the Reynolds number approaches 1. Foam exhibits effective control of gas mobility. Foam flow resistances are approximately 10 to 20 times greater than those of nitrogen over foam qualities spanning from 0.60 to 0.99 indicating effective gas-mobility control. Because previous studies of foam flow have focused mainly upon unfractured porous media, little information is available about foam flow mechanisms in fractured media. The transparency of the fracture allowed flow visualization and demonstrated that foam rheology in fractured media depends upon bubble shape and size. Changes in flow behavior are directly tied to transitions in bubble morphology.

Kovscek, A.; Tretheway, D.; Radke, C. [and others

1995-07-01T23:59:59.000Z

207

Temporary Sealing of Fractures | Open Energy Information  

Open Energy Info (EERE)

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

208

Ductile Fracture Handbook: Volume 2  

Science Conference Proceedings (OSTI)

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

1990-09-01T23:59:59.000Z

209

Ductile Fracture Handbook: Volume 3  

Science Conference Proceedings (OSTI)

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

1990-09-01T23:59:59.000Z

210

Identification of Parameters Influencing the Response of Gas Storage Wells to Hydraulic Fracturing with the Aid of a Neural Network  

E-Print Network (OSTI)

located in Northeastern Ohio. The formation is a tight gas sandstone called the Clinton Sand. All was trained with existing data to identify influential parameters in hydraulic fracturing of the Clinton Sand Characteristics The Clinton reservoir is a tight gas sandstone. Natural fracturing is thought to account

Mohaghegh, Shahab

211

A casting and imaging technique for determining void geometry and relative permeability behavior of a single fracture specimen  

DOE Green Energy (OSTI)

A casting technique has been developed for making translucent replicas of the void space of natural rock fractures. Attenuation of light shined through the cast combined with digital image analysis provides a pointwise definition of fracture apertures. The technique has been applied to a fracture specimen from Dixie Valley, Nevada, and the measured void space geometry has been used to develop theoretical predictions of two-phase relative permeability. A strong anisotropy in relative permeabilities has been found, which is caused by highly anisotropic spatial correlations among fracture apertures. 16 refs., 6 figs.

Cox, B.L.; Pruess, K.; Persoff, P.

1990-01-01T23:59:59.000Z

212

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

E-Print Network (OSTI)

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

Wu, Yu-Shu; Pruess, Karsten

2004-01-01T23:59:59.000Z

213

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

E-Print Network (OSTI)

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

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

2004-01-01T23:59:59.000Z

214

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

E-Print Network (OSTI)

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

McKinney, Scott D

2013-01-01T23:59:59.000Z

215

Evidence of Reopened Microfractures in Production Data of Hydraulically Fractured Shale Gas Wells  

E-Print Network (OSTI)

Frequently a discrepancy is found between the stimulated shale volume (SSV) estimated from production data and the SSV expected from injected water and proppant volume. One possible explanation is the presence of a fracture network, often termed fracture complexity, that may have been opened or reopened during the hydraulic fracturing operation. The main objective of this work is to investigate the role of fracture complexity in resolving the apparent SSV discrepancy and to illustrate whether the presence of reopened natural fracture network can be observed in pressure and production data of shale gas wells producing from two shale formations with different well and reservoir properties. Homogeneous, dual porosity and triple porosity models are investigated. Sensitivity runs based on typical parameters of the Barnett and the Horn River shale are performed. Then the field data from the two shales are matched. Homogeneous models for the two shale formations indicate effective infinite conductivity fractures in the Barnett well and only moderate conductivity fractures in the Horn River shale. Dual porosity models can support effectively infinite conductivity fractures in both shale formations. Dual porosity models indicate that the behavior of the Barnett and Horn River shale formations are different. Even though both shales exhibit apparent bilinear flow behavior the flow behaviors during this trend are different. Evidence of this difference comes from comparing the storativity ratio observed in each case to the storativity ratio estimated from injected fluid volumes during hydraulic fracturing. In the Barnett shale case similar storativity ratios suggest fracture complexity can account for the dual porosity behavior. In the Horn River case, the model based storativity ratio is too large to represent only fluids from hydraulic fracturing and suggests presence of existing shale formation microfractures.

Apiwathanasorn, Sippakorn

2012-08-01T23:59:59.000Z

216

Nonisothermal injection tests in fractured reservoirs  

DOE Green Energy (OSTI)

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

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

1985-01-01T23:59:59.000Z

217

Mapping acoustic emissions from hydraulic fracture treatments using coherent array processing: Concept  

DOE Green Energy (OSTI)

Hydraulic fracturing is a widely-used well completion technique for enhancing the recovery of gas and oil in low-permeability formations. Hydraulic fracturing consists of pumping fluids into a well under high pressure (1000--5000 psi) to wedge-open and extend a fracture into the producing formation. The fracture acts as a conduit for gas and oil to flow back to the well, significantly increasing communication with larger volumes of the producing formation. A considerable amount of research has been conducted on the use of acoustic (microseismic) emission to delineate fracture growth. The use of transient signals to map the location of discrete sites of emission along fractures has been the focus of most research on methods for delineating fractures. These methods depend upon timing the arrival of compressional (P) or shear (S) waves from discrete fracturing events at one or more clamped geophones in the treatment well or in adjacent monitoring wells. Using a propagation model, the arrival times are used to estimate the distance from each sensor to the fracturing event. Coherent processing methods appear to have sufficient resolution in the 75 to 200 Hz band to delineate the extent of fractures induced by hydraulic fracturing. The medium velocity structure must be known with a 10% accuracy or better and no major discontinuities should be undetected. For best results, the receiving array must be positioned directly opposite the perforations (same depths) at a horizontal range of 200 to 400 feet from the region to be imaged. Sources of acoustic emission may be detectable down to a single-sensor SNR of 0.25 or somewhat less. These conclusions are limited by the assumptions of this study: good coupling to the formation, acoustic propagation, and accurate knowledge of the velocity structure.

Harris, D.B.; Sherwood, R.J.; Jarpe, S.P.; Harben, P.E.

1991-09-01T23:59:59.000Z

218

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

219

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

220

Effects of dry fractures on matrix diffusion in unsaturated fractured rocks  

E-Print Network (OSTI)

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

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

2002-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "natural fracture detection" 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

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

Science Conference Proceedings (OSTI)

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

Moubin Liu; Paul Meakin; Hai Huang

2007-03-01T23:59:59.000Z

222

Summary of Linear Elastic Fracture Mechanics Concepts  

Science Conference Proceedings (OSTI)

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

223

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

Science Conference Proceedings (OSTI)

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

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

2010-08-01T23:59:59.000Z

224

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

Science Conference Proceedings (OSTI)

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

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

2006-05-15T23:59:59.000Z

225

The Dynamics of Rapid Fracture: Instabilities, Nonlinearities and Length Scales  

E-Print Network (OSTI)

The failure of materials and interfaces is mediated by cracks, nearly singular dissipative structures that propagate at velocities approaching the speed of sound. Crack initiation and subsequent propagation -- the dynamic process of fracture -- couples a wide range of time and length scales. Crack dynamics challenge our understanding of the fundamental physics processes that take place in the extreme conditions within the nearly singular region where material failure occurs. Here, we first briefly review the classic approach to dynamic fracture, "Linear Elastic Fracture Mechanics" (LEFM), and discuss its successes and limitations. We show how, on the one hand, recent experiments performed on straight cracks propagating in soft brittle materials have quantitatively confirmed the predictions of this theory to an unprecedented degree. On the other hand, these experiments show how LEFM breaks down as the singular region at the tip of a crack is approached. This breakdown naturally leads to a new theoretical framework coined "Weakly Nonlinear Fracture Mechanics", where weak elastic nonlinearities are incorporated. The stronger singularity predicted by this theory gives rise to a new and intrinsic length scale, $\\ell_{nl}$. These predictions are verified in detail through direct measurements. We then theoretically and experimentally review how the emergence of $\\ell_{nl}$ is linked to a new equation for crack motion, which predicts the existence of a high-speed oscillatory crack instability whose wave-length is determined by $\\ell_{nl}$. We conclude by delineating outstanding challenges in the field.

Eran Bouchbinder; Tamar Goldman; Jay Fineberg

2013-05-05T23:59:59.000Z

226

Developing Next Generation Natural Fracture Dectection and Prediction...  

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

(as available) to create a composite georeferenced water chemistry resource to support exploration and production activities across the GGRB and WRB. A digital atlas showing the...

227

A Political Ecology of Hydraulic Fracturing for Natural Gas in  

E-Print Network (OSTI)

[:] shale gas in the US, sand mines in Wisconsin, oil in the Ecuadoran Amazon, oil in the Niger Delta's Marcellus Shale Laura J. Stroup, Ph.D. Dept. of Geography, Texas State University Michael H. Finewood, Ph ! Background of Marcellus Shale Gas Play ! Current Events: The Case of PA ! Geography of Fracking in Study

Scott, Christopher

228

The effect of natural fracture characteristics on current analytical models for hydraulically fractured unconventional shale reservoirs.  

E-Print Network (OSTI)

??In recent years, the oil and gas industry has shifted its focus more towards unconventional shale reservoirs. It has become apparent that these reservoirs require… (more)

Junor, Nathaniel T.

2013-01-01T23:59:59.000Z

229

Geomechanical Simulation of Fluid-Driven Fractures  

SciTech Connect

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

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

2012-11-30T23:59:59.000Z

230

Structural Settings Of Hydrothermal Outflow- Fracture Permeability  

Open Energy Info (EERE)

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

231

VSP [Vertical Seismic Profiling] and cross hole tomographic imaging for fracture characterization  

SciTech Connect

For the past several years LBL has been carrying out experiments at various fractured rock sites to determine the fundamental nature of the propagation of seismic waves in fractured media. These experiments have been utilizing high frequency (1000 to 10000 Hz.) signals in a cross-hole configuration at scales of several tens of meters. Three component sources and receivers are used to map fracture density, and orientation. The goal of the experiments has been to relate the seismological parameters to the hydrological parameters, if possible, in order to provide a more accurate description of a starting model for hydrological characterization. The work is ultimately aimed at the characterization and monitoring of the Yucca Mountain site for the storage of nuclear waste. In addition to these controlled experiments multicomponent VSP work has been carried out at several sites to determine fracture characteristics. The results to date indicate that both P-wave and S-wave can be used to map the location of fractures. In addition, fractures that are open and conductive are much more visible to seismic waves that non-conductive fractures. The results of these tests indicate direct use in an unsaturated environment. 12 refs., 10 figs.

Majer, E.L.; Peterson, J.E.; Myer, L.R.; Karasaki, K.; Daley, T.M.; Long, J.C.S.

1989-09-01T23:59:59.000Z

232

RESEARCH PROGRAM ON FRACTURED PETROLEUM RESERVOIRS  

Science Conference Proceedings (OSTI)

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

Abbas Firoozabadi

2002-04-12T23:59:59.000Z

233

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

234

Vaporizing Flow in Hot Fractures: Observations from Laboratory Experiments  

DOE Green Energy (OSTI)

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

Kneafsey, T.; Pruess, K.

1998-12-01T23:59:59.000Z

235

In situ stress, fracture, and fluid flow analysis in Well 38C-9: an  

Open Energy Info (EERE)

In situ stress, fracture, and fluid flow analysis in Well 38C-9: an In situ stress, fracture, and fluid flow analysis in Well 38C-9: an enhanced geothermal system in the Coso geothermal field Jump to: navigation, search OpenEI Reference LibraryAdd to library Conference Paper: In situ stress, fracture, and fluid flow analysis in Well 38C-9: an enhanced geothermal system in the Coso geothermal field Abstract Geoscientists from the Coso Operating Company, EGI-Utah, GeoMechanics International, and the U.S. Geological Survey are cooperating in a multi-year study to develop an Enhanced Geothermal System (EGS) in the Coso Geothermal Field. Key to the creation of an EGS is an understanding of the relationship among natural fracture distribution, fluid flow, and the ambient tectonic stresses that exist within the resource in order to design

236

Fracture orientation analysis by the solid earth tidal strain method | Open  

Open Energy Info (EERE)

orientation analysis by the solid earth tidal strain method orientation analysis by the solid earth tidal strain method Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Journal Article: Fracture orientation analysis by the solid earth tidal strain method Details Activities (1) Areas (1) Regions (0) Abstract: A new practical method has been developed to estimate subsurface fracture orientation based on an analysis of solid earth tidal strains. The tidal strain fracture orientation technique is a passive method which has no depth limitation. The orientation of either natural or hydraulically stimulated fractures can be measured using either new or old static observation wells. Estimates for total compressibility and areal interconnected porosity can also be developed for reservoirs with matrix permeability using a combination of tidal and barometric strain analysis.

237

IN SITU STRESS, FRACTURE, AND FLUID FLOW ANALYSIS IN WELL 38C-9:AN ENHANCED  

Open Energy Info (EERE)

FRACTURE, AND FLUID FLOW ANALYSIS IN WELL 38C-9:AN ENHANCED FRACTURE, AND FLUID FLOW ANALYSIS IN WELL 38C-9:AN ENHANCED GEOTHERMAL SYSTEM IN THE COSO GEOTHERMAL FIELD Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Conference Proceedings: IN SITU STRESS, FRACTURE, AND FLUID FLOW ANALYSIS IN WELL 38C-9:AN ENHANCED GEOTHERMAL SYSTEM IN THE COSO GEOTHERMAL FIELD Details Activities (2) Areas (1) Regions (0) Abstract: Geoscientists from the Coso Operating Company, EGI-Utah, GeoMechanics International, and the U.S. Geological Survey are cooperating in a multi-year study to develop an Enhanced Geothermal System (EGS) in the Coso Geothermal Field. Key to the creation of an EGS is an understanding of the relationship among natural fracture distribution, fluid flow, and the ambient tectonic stresses that exist within the resource in order to design

238

On the multiscale origins of fracture resistance in human bone and its biological degradation  

SciTech Connect

Akin to other mineralized tissues, human cortical bone can resist deformation and fracture due to the nature of its hierarchical structure, which spans the molecular to macroscopic length-scales. Deformation at the smallest scales, mainly through the composite action of the mineral and collagen, contributes to bone?s strength or intrinsic fracture resistance, while crack-tip shielding mechanisms active on the microstructural scale contribute to the extrinsic fracture resistance once cracking begins. The efficiency with which these structural features can resist fracture at both small and large length-scales becomes severely degraded with such factors as aging, irradiation and disease. Indeed aging and irradiation can cause changes to the cross-link profile at fibrillar length-scales as well as changes at the three orders of magnitude larger scale of the osteonal structures, both of which combine to inhibit the bone's overall resistance to the initiation and growth of cracks.

Zimmermann, Elizabeth A.; Barth, Holly D.; Ritchie, Robert O.

2012-03-09T23:59:59.000Z

239

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

E-Print Network (OSTI)

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

Correa Castro, Juan

2011-05-01T23:59:59.000Z

240

Numerical Modeling of Hydraulic Fracture Propagation Using Thermo-hydro-mechanical Analysis with Brittle Damage Model by Finite Element Method  

E-Print Network (OSTI)

Better understanding and control of crack growth direction during hydraulic fracturing are essential for enhancing productivity of geothermal and petroleum reservoirs. Structural analysis of fracture propagation and impact on fluid flow is a challenging issue because of the complexity of rock properties and physical aspects of rock failure and fracture growth. Realistic interpretation of the complex interactions between rock deformation, fluid flow, heat transfer, and fracture propagation induced by fluid injection is important for fracture network design. In this work, numerical models are developed to simulate rock failure and hydraulic fracture propagation. The influences of rock deformation, fluid flow, and heat transfer on fracturing processes are studied using a coupled thermo-hydro-mechanical (THM) analysis. The models are used to simulate microscopic and macroscopic fracture behaviors of laboratory-scale uniaxial and triaxial experiments on rock using an elastic/brittle damage model considering a stochastic heterogeneity distribution. The constitutive modeling by the energy release rate-based damage evolution allows characterizing brittle rock failure and strength degradation. This approach is then used to simulate the sequential process of heterogeneous rock failures from the initiation of microcracks to the growth of macrocracks. The hydraulic fracturing path, especially for fractures emanating from inclined wellbores and closed natural fractures, often involves mixed mode fracture propagation. Especially, when the fracture is inclined in a 3D stress field, the propagation cannot be modeled using 2D fracture models. Hence, 2D/3D mixed-modes fracture growth from an initially embedded circular crack is studied using the damage mechanics approach implemented in a finite element method. As a practical problem, hydraulic fracturing stimulation often involves fluid pressure change caused by injected fracturing fluid, fluid leakoff, and fracture propagation with brittle rock behavior and stress heterogeneities. In this dissertation, hydraulic fracture propagation is simulated using a coupled fluid flow/diffusion and rock deformation analysis. Later THM analysis is also carried out. The hydraulic forces in extended fractures are solved using a lubrication equation. Using a new moving-boundary element partition methodology (EPM), fracture propagation through heterogeneous media is predicted simply and efficiently. The method allows coupling fluid flow and rock deformation, and fracture propagation using the lubrication equation to solve for the fluid pressure through newly propagating crack paths. Using the proposed model, the 2D/3D hydraulic fracturing simulations are performed to investigate the role of material and rock heterogeneity. Furthermore, in geothermal and petroleum reservoir design, engineers can take advantage of thermal fracturing that occurs when heat transfers between injected flow and the rock matrix to create reservoir permeability. These thermal stresses are calculated using coupled THM analysis and their influence on crack propagation during reservoir stimulation are investigated using damage mechanics and thermal loading algorithms for newly fractured surfaces.

Min, Kyoung

2013-08-01T23:59:59.000Z

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241

Smolt Migration Characteristics and Mainstem Snake and Columbia River Detection Rates of PIT-Tagged Grande Ronde and Imnaha River Naturally Produced Spring Chinook Salmon, Annual Reports 1993, 1994, 1995 : Fish Research Project, Oregon.  

DOE Green Energy (OSTI)

This reports on the second, third, and fourth years of a multi-year study to assess smolt migration characteristics and cumulative detection rates of naturally produced spring chinook salmon (Oncorhynchus tshawytscha) from Northeast Oregon streams. The goal of this project is to develop an understanding of interpopulational and interannual variation in several early life history parameters of naturally produced spring and summer chinook salmon in the Grande Ronde and Imnaha River subbasins. This project will provide information to assist chinook salmon population recovery efforts. Specific populations included in the study are: (1) Catherine Creek; (2) Upper Grande Ronde River; (3) Lostine River; (4) Imnaha River; (5) Wenaha River; and (6) Minam River. In this document, the authors present findings and activities from research completed in 1993, 1994, and 1995.

Walters, Timothy R.; Carmichael, Richard W.; Keefe, MaryLouise

1996-04-01T23:59:59.000Z

242

Hydraulic Fracturing Data Collection Tools Improve Environmental Reporting,  

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

8, 2013 8, 2013 Hydraulic Fracturing Data Collection Tools Improve Environmental Reporting, Monitoring, Protection Washington, D.C. -Two data collection tools specifically developed for hydraulic fracturing are available to help regulatory agencies monitor drilling and completion operations and enhance environmental protection. Developed with support from the U.S. Department of Energy's Office of Fossil Energy (FE), the Risk Based Data Management System (RBDMS) and FracFocus chemical disclosure registry (http://fracfocus.org/) provide a way for industry professionals, regulatory agencies and the general public to more easily access information on oil and natural gas activities. These reporting and data collection tools have been developed by the Groundwater Protection Council (GWPC) and various states.

243

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

244

Hydraulic fracturing of jointed formations  

DOE Green Energy (OSTI)

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

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

1986-01-01T23:59:59.000Z

245

Fluid Flow Within Fractured Porous Media  

Science Conference Proceedings (OSTI)

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

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

2006-10-01T23:59:59.000Z

246

Well test analysis in fractured media  

DOE Green Energy (OSTI)

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

Karasaki, K.

1987-04-01T23:59:59.000Z

247

Nonlinear Hertzian indentation fracture mechanics  

SciTech Connect

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

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

1995-09-01T23:59:59.000Z

248

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

SciTech Connect

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

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

1998-12-01T23:59:59.000Z

249

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

E-Print Network (OSTI)

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

Faybishenko, Boris; Witherspoon, Paul A.

2004-01-01T23:59:59.000Z

250

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

251

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

E-Print Network (OSTI)

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

Marpaung, Fivman

2007-12-01T23:59:59.000Z

252

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

E-Print Network (OSTI)

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

Marpaung, Fivman

2007-12-01T23:59:59.000Z

253

Using seismic tomography to characterize fracture systems induced by hydraulic fracturing  

DOE Green Energy (OSTI)

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

Fehler, M.; Rutledge, J.

1995-01-01T23:59:59.000Z

254

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

255

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

256

Injection into a fractured geothermal reservoir  

DOE Green Energy (OSTI)

A detailed study is made on the movement of the thermal fronts in the fracture and in the porous medium when 100{sup 0}C water is injected into a 300{sup 0}C geothermal reservoir with equally spaced horizontal fractures. Numerical modeling calculations were made for a number of thermal conductivity values, as well as different values of the ratio of fracture and rock medium permeabilities. One important result is an indication that although initially, the thermal front in the fracture moves very fast relative to the front in the porous medium as commonly expected, its speed rapidly decreases. At some distance from the injection well the thermal fronts in the fracture and the porous medium coincide, and from that point they advance together. The implication of this result on the effects of fractures on reinjection into geothermal reservoirs is discussed.

Bodvarsson, G.S.; Tsang, C.F.

1980-05-01T23:59:59.000Z

257

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

Science Conference Proceedings (OSTI)

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

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

2008-07-01T23:59:59.000Z

258

Characterization of EGS Fracture Network Lifecycles  

DOE Green Energy (OSTI)

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

Gillian R. Foulger

2008-03-31T23:59:59.000Z

259

A finite element model for three dimensional hydraulic fracturing  

Science Conference Proceedings (OSTI)

This paper is devoted to the development of a model for the numerical simulation of hydraulic fracturing processes with 3d fracture propagation. It takes into account the effects of fluid flow inside the fracture, fluid leak-off through fracture walls ... Keywords: boundary elements, finite elements, hydraulic fracturing, petroleum recovery

Philippe R. B. Devloo; Paulo Dore Fernandes; Sônia M. Gomes; Cedric Marcelo Augusto Ayala Bravo; Renato Gomes Damas

2006-11-01T23:59:59.000Z

260

Experimental Investigation of Propped Fracture Conductivity in Tight Gas Reservoirs Using The Dynamic Conductivity Test  

E-Print Network (OSTI)

Hydraulic Fracturing stimulation technology is used to increase the amount of oil and gas produced from low permeability reservoirs. The primary objective of the process is to increase the conductivity of the reservoir by the creation of fractures deep into the formation, changing the flow pattern from radial to linear flow. The dynamic conductivity test was used for this research to evaluate the effect of closure stress, temperature, proppant concentration, and flow back rates on fracture conductivity. The objective of performing a dynamic conductivity test is to be able to mimic actual field conditions by pumping fracturing fluid/proppant slurry fluid into a conductivity cell, and applying closure stress afterwards. In addition, a factorial design was implemented in order to determine the main effect of each of the investigated factors and to minimize the number of experimental runs. Due to the stochastic nature of the dynamic conductivity test, each experiment was repeated several times to evaluate the consistency of the results. Experimental results indicate that the increase in closure stress has a detrimental effect on fracture conductivity. This effect can be attributed to the reduction in fracture width as closure stress was increased. Moreover, the formation of channels at low proppant concentration plays a significant role in determining the final conductivity of a fracture. The presence of these channels created an additional flow path for nitrogen, resulting in a significant increase in the conductivity of the fracture. In addition, experiments performed at high temperatures and stresses exhibited a reduction in fracture conductivity. The formation of a polymer cake due to unbroken gel dried up at high temperatures further impeded the propped conductivity. The effect of nitrogen rate was observed to be inversely proportional to fracture conductivity. The significant reduction in fracture conductivity could possibly be due to the effect of polymer dehydration at higher flow rates and temperatures. However, there is no certainty from experimental results that this conductivity reduction is an effect that occurs in real fractures or whether it is an effect that is only significant in laboratory conditions.

Romero Lugo, Jose 1985-

2012-12-01T23:59:59.000Z

Note: This page contains sample records for the topic "natural fracture detection" 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

Hydraulic fracturing and shale gas extraction.  

E-Print Network (OSTI)

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

Klein, Michael

2012-01-01T23:59:59.000Z

262

Geothermal: Sponsored by OSTI -- Injection through fractures  

Office of Scientific and Technical Information (OSTI)

Injection through fractures Geothermal Technologies Legacy Collection HelpFAQ | Site Map | Contact Us | Admin Log On HomeBasic Search About Publications Advanced Search New Hot...

263

Fatigue and Fracture I - Programmaster.org  

Science Conference Proceedings (OSTI)

Oct 10, 2012 ... Fretting Corrosion Induced Fracture of a Floating Bearing Base Plate in a 250 Tons Yankee Paper Drum: Pierre Dupont1; 1Schaeffler Belgium ...

264

Hydraulic fractures traced by monitoring microseismic events  

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

Summary: The trend toward production of hydrocarbons from unconventional reservoirs (tight gas, shale oilgas) has caused a large increase in the use of hydraulic fracture...

265

Structural Settings Of Hydrothermal Outflow- Fracture Permeability...  

Open Energy Info (EERE)

elevated stress termed breakdown regions. Here, stress concentrations cause active fracturing and continual re-opening of fluid-flow conduits, permitting long-lived hydrothermal...

266

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

267

Fracture of Thin Films and Nanomaterials  

Science Conference Proceedings (OSTI)

Mar 4, 2013 ... Fracture Toughness of SPD-Deformed Nanostructured Rail Steels and Its Implications on the In-Service Behaviour: Christoph Kammerhofer1; ...

268

Deformation and Fracture - Programmaster.org  

Science Conference Proceedings (OSTI)

Mar 14, 2012 ... Investigations on the crack propagation resistance showed an increasing fracture resistance with crack extension, so-called R-curve behavior.

269

Microseismic Tracer Particles for Hydraulic Fracturing  

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

The trend toward production of hydrocarbons from unconventional reservoirs (tight gas, shale oilgas) has caused a large increase in the use of hydraulic fracture stimulation of...

270

Molecular Dynamics Simulation of Thermoset Fracture with ...  

Science Conference Proceedings (OSTI)

The effects of resin chain extensibility and dilution on fracture behavior are studied by testing a variety of molecular systems. The molecular bases for precursors ...

271

MML Leads Discussion of Dynamic Fracture Testing  

Science Conference Proceedings (OSTI)

Dynamic Fracture in Steel. ... More recently, the pipeline industry has been adopting the CTOA ... fatigue characteristics of new pipeline steels, as these ...

2012-10-15T23:59:59.000Z

272

Well test analysis in fractured media  

DOE Green Energy (OSTI)

In this study the behavior of fracture systems under well test conditions and methods for analyzing well test data from fractured media are investigated. Several analytical models are developed to be used for analyzing well test data from fractured media. Numerical tools that may be used to simulate fluid flow in fractured media are also presented. Three types of composite models for constant flux tests are investigated. Several slug test models with different geometric conditions that may be present in fractured media are also investigated. A finite element model that can simulate transient fluid flow in fracture networks is used to study the behavior of various two-dimensional fracture systems under well test conditions. A mesh generator that can be used to model mass and heat flow in a fractured-porous media is presented. This model develops an explicit solution in the porous matrix as well as in the discrete fractures. Because the model does not require the assumptions of the conventional double porosity approach, it may be used to simulate cases where double porosity models fail.

Karasaki, K.

1986-04-01T23:59:59.000Z

273

Geothermal: Sponsored by OSTI -- Hydraulic fracturing: insights...  

Office of Scientific and Technical Information (OSTI)

Hydraulic fracturing: insights from field, lab, and numerical studies Geothermal Technologies Legacy Collection HelpFAQ | Site Map | Contact Us | Admin Log On HomeBasic Search...

274

Enhancing in situ bioremediation with pneumatic fracturing  

Science Conference Proceedings (OSTI)

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

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

1994-04-01T23:59:59.000Z

275

The Rise of Shale Gas: Implications of the shale gas boom for natural gas markets, environmental protection and U.S. energy policy.  

E-Print Network (OSTI)

??Through the processes of hydraulic fracturing and horizontal drilling, once overlooked deposits of natural gas in shale formations have become economically viable to extract. In… (more)

Lovejoy, Cassandra L.

2012-01-01T23:59:59.000Z

276

Method for FractMethod for Fracture Detection Using ...  

Wind Energy; Partners (27) Visual Patent Search; Success Stories; ... Web Site Policies | U.S. Department of Energy | USA.gov Content Last Updated: ...

277

FRACTURE DETECTION IN CRYSTALLINE ROCK USING ULTRASONIC SHEAR WAVES  

E-Print Network (OSTI)

of Energy, or the Swedish Nuclear Fuel Supply Company.through the Swedish Nuclear Fuel Supply Company (SKBF), andEnergy and/or the Swedish Nuclear Fuel Supply Company. Any

Waters, K.H.

2011-01-01T23:59:59.000Z

278

FRACTURE DETECTION IN CRYSTALLINE ROCK USING ULTRASONIC SHEAR WAVES  

E-Print Network (OSTI)

the piezoelectric source plate and the rock surface. With aThe S^j sources were bonded to the rock surface with a fast-^ source plate was epoxied in position on the rock specimen.

Waters, K.H.

2011-01-01T23:59:59.000Z

279

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

SciTech Connect

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

280

Fracture mechanics of oil shale: some preliminary results  

SciTech Connect

Results of a comprehensive series of fracture toughness tests on oil shale from Anvil Points are presented. Since oil shale is layered and transversely isotropic, three-point-bend specimens representing 20 and 40 gal/ton were tested in the three principal crack orientations--divider, arrester, and short transverse. These specimens were fatigue cracked to produce a sharp natural crack in a stable manner by means of loading between fixed limits of the crack opening displacement. Crack front position was marked by immersing the specimen in a penetrating dye so that the crack length could be determined after final failure. Load-to-failure records of load vs. crack opening displacement showed evidence of crack surface interference or crack closure. Fracture toughness was found to decrease by approximately 40 percent for an increase in kerogen content from 20 to 40 gal/ton. Highest values of fracture toughness were found for the divider geometry, lowest for short transverse, and intermediate for arrester with the actual values varying from 0.3 to 1.1 MN m/sup -/sup 3///sub 2/.

Schmidt, R.A. Huddle, C.W.

1977-02-01T23:59:59.000Z

Note: This page contains sample records for the topic "natural fracture detection" 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

SPHDOE 35396 Analysis of Hydrofracture Geometry and Matrix/Fracture Interactions During  

E-Print Network (OSTI)

the perforated interval of the upper injection well suggests that a horizontal fracture, or network of natural that roughly 43 percent of the total injected steam migrated above the perforations of the injection well view of the Phase II pilot area including injection, production, and monitoring wells. The two

Patzek, Tadeusz W.

282

GMINC - A MESH GENERATOR FOR FLOW SIMULATIONS IN FRACTURED RESERVOIRS  

E-Print Network (OSTI)

Simulation of Fluid Flow in Fractured Porous Media, Watergovern fluid flow in fractured porous media. These are (i)for Modeling Fluid and Heat Flow in fractured Porous Media,

Pruess, K.

2010-01-01T23:59:59.000Z

283

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

284

Searching, naturally  

Science Conference Proceedings (OSTI)

Keywords: artificial intelligence, computational linguistics, information retrieval, knowledge representation, natural language processing, text processing

Eileen E. Allen

1998-06-01T23:59:59.000Z

285

Dynamic Fracture Conductivity—An Experimental Investigation Based on Factorial Analysis  

E-Print Network (OSTI)

This work is about fracture conductivity; how to measure and model it based on experimental data. It is also about how to determine the relative importance of the factors that affect its magnitude and how to predict its magnitude based on these factors. We dynamically placed the slurry hereby simulating the slurry placement procedure in a field-scale fracture. We also used factorial and fractional factorial designs as the basis of our experimental investigation. The analysis and interpretation of experimental results take into account the stochastic nature of the process. We found that the relative importance of the investigated factors is dependent on the presence of outliers and how they are handled. Based on our investigation we concluded that the investigated factors arranged in order of decreasing impact on conductivity are: closure stress, polymer loading, flow back rate, presence of breaker, temperature and proppant concentration. In particular, we find that at high temperatures, fracture conductivity was severely reduced due to the formation of a dense proppant-polymer cake. Also, dehydration of the residual gel in the fracture at high flow back rates appears to cause severe damage to conductivity at higher temperatures. This represents a new way of thinking about the fracture cleanup process; not only as a displacement process, but also as a displacement and evaporative process. In engineering practice, this implies that aggressive flow back schemes are not necessarily beneficial for conductivity development. Also, we find that at low proppant concentrations, there is the increased likelihood of the formation of channels and high porosity fractures resulting in high fracture conductivities. The uniqueness of this work is a focus on the development of a conductivity model using regression analysis and also the illustration of a procedure that can be used to develop a conductivity model using dimensional analysis. We reviewed both methodologies and applied them to the challenge of modeling fracture conductivity from experimental studies.

Awoleke, Obadare O

2013-05-01T23:59:59.000Z

286

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

SciTech Connect

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

Petti, Jason P.; Kalan, Robert J.

2011-12-01T23:59:59.000Z

287

Permeability enhancement using high energy gas fracturing  

DOE Green Energy (OSTI)

This paper reports the results of a preliminary study of using High Energy Gas Fracturing (HEGF) techniques for geothermal well stimulation. Experiments conducted in the G-tunnel complex at the Nevada Test Site (NTS) showed that multiple fractures could be created in water-filled boreholes using HEGF. Therefore, the method is potentially useful for geothermal well stimulation. 4 refs., 11 figs.

Chu, T.Y.; Cuderman, J.F.; Jung, J.; Jacobson, R.D.

1986-01-01T23:59:59.000Z

288

SECONDARY NATURAL GAS RECOVERY IN THE APPALACHIAN BASIN: APPLICATION OF ADVANCED TECHNOLOGIES IN A FIELD DEMONSTRATION SITE, HENDERSON DOME, WESTERN PENNSYLVANIA  

Science Conference Proceedings (OSTI)

The principal objectives of this project were to test and evaluate technologies that would result in improved characterization of fractured natural-gas reservoirs in the Appalachian Basin. The Bureau of Economic Geology (Bureau) worked jointly with industry partner Atlas Resources, Inc. to design, execute, and evaluate several experimental tests toward this end. The experimental tests were of two types: (1) tests leading to a low-cost methodology whereby small-scale microfractures observed in matrix grains of sidewall cores can be used to deduce critical properties of large-scale fractures that control natural-gas production and (2) tests that verify methods whereby robust seismic shear (S) waves can be generated to detect and map fractured reservoir facies. The grain-scale microfracture approach to characterizing rock facies was developed in an ongoing Bureau research program that started before this Appalachian Basin study began. However, the method had not been tested in a wide variety of fracture systems, and the tectonic setting of rocks in the Appalachian Basin composed an ideal laboratory for perfecting the methodology. As a result of this Appalachian study, a low-cost commercial procedure now exists that will allow Appalachian operators to use scanning electron microscope (SEM) images of thin sections extracted from oriented sidewall cores to infer the spatial orientation, relative geologic timing, and population density of large-scale fracture systems in reservoir sandstones. These attributes are difficult to assess using conventional techniques. In the Henderson Dome area, large quartz-lined regional fractures having N20E strikes, and a subsidiary set of fractures having N70W strikes, are prevalent. An innovative method was also developed for obtaining the stratigraphic and geographic tops of sidewall cores. With currently deployed sidewall coring devices, no markings from which top orientation can be obtained are made on the sidewall core itself during drilling. The method developed in this study involves analysis of the surface morphology of the broken end of the core as a top indicator. Together with information on the working of the tool (rotation direction), fracture-surface features, such as arrest lines and plume structures, not only give a top direction for the cores but also indicate the direction of fracture propagation in the tough, fine-grained Cataract/Medina sandstones. The study determined that microresistivity logs or other image logs can be used to obtain accurate sidewall core azimuths and to determine the precise depths of the sidewall cores. Two seismic S-wave technologies were developed in this study. The first was a special explosive package that, when detonated in a conventional seismic shot hole, produces more robust S-waves than do standard seismic explosives. The importance of this source development is that it allows S-wave seismic data to be generated across all of the Appalachian Basin. Previously, Appalachian operators have not been able to use S-wave seismic technology to detect fractured reservoirs because the industry-standard S-wave energy source, the horizontal vibrator, is not a practical source option in the heavy timber cover that extends across most of the basin. The second S-wave seismic technology that was investigated was used to verify that standard P-wave seismic sources can create robust downgoing S-waves by P-to-S mode conversion in the shallow stratigraphic layering in the Appalachian Basin. This verification was done by recording and analyzing a 3-component vertical seismic profile (VSP) in the Atlas Montgomery No. 4 well at Henderson Dome, Mercer County, Pennsylvania. The VSP data confirmed that robust S-waves are generated by P-to-S mode conversion at the basinwide Onondaga stratigraphic level. Appalachian operators can thus use converted-mode seismic technology to create S-wave images of fractured and unfractured rock systems throughout the basin.

BOB A. HARDAGE; ELOISE DOHERTY; STEPHEN E. LAUBACH; TUCKER F. HENTZ

1998-08-14T23:59:59.000Z

289

Finding Large Aperture Fractures in Geothermal Resource Areas...  

Open Energy Info (EERE)

low-permeability fractures and LAF's (Large Aperature Fractures). USG will develop and test the combination of three-component,long-offset seismic surveying, permanent scatter...

290

Characterizing Fractures in Geysers Geothermal Field by Micro...  

Open Energy Info (EERE)

water through existing fractures into hot wet and hot dry rocks by thermo-elastic cooling shrinkage. The stimulated, existing fractures thus enhance the permeability of the...

291

Modeling Of Hydraulic Fracture Network Propagation In Shale Gas Reservoirs.  

E-Print Network (OSTI)

??The most effective method for stimulating shale gas reservoirs is massive hydraulic fracture treatments. Recent fracture diagnostic technologies such as microseismic technology have shown that… (more)

Ahn, Chong

2012-01-01T23:59:59.000Z

292

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

Open Energy Info (EERE)

Microearthquakes in the geothermal field are proposed as indicators of shear fracturing associated with fluid injection and circulation along major pre-existing fractures....

293

A physical model for fracture surface features in metallic glasses  

Science Conference Proceedings (OSTI)

Apr 30, 2010 ... at a rate of 1000 mm/ min, fracturing the grease in the sample. Photographs were then taken of the fracture surfaces. The photographs were ...

294

Irradiation Effects on Human Cortical Bone Fracture Behavior  

NLE Websites -- All DOE Office Websites (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...

295

An Alternate Approach for Characterizing the Fracture Resistance of ...  

Science Conference Proceedings (OSTI)

While the elastic properties and strength of fish scales have received considerable attention, the resistance to fracture has not. Here the fracture resistance of ...

296

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

297

Optimization of Construction Discharge Rate and Proppant Slugs for Preventing Complex Fractures  

Science Conference Proceedings (OSTI)

For volcanic rock and fracture type reservoir, etc, steering fractures, branching fractures and their combined herringbone fractures are usually caused by hydraulic fracturing. The generation of these complex fractures is one of the crucial factors that ... Keywords: hydraulic fracturing, construction discharge rate, complex fractures, proppant slug, optimization

Dali Guo; Yang Lin; Yong Ji; Jiangwen Xu; Guobin Wang

2011-10-01T23:59:59.000Z

298

Occult fractures of the knee: tomographic evaluation  

SciTech Connect

Seven adults with painful effusions of the knee were examined for occult fractures using pluridirectional tomograph in the coronal and lateral planes. Six patients (ages 50 to 82 years) were osteopenic and gave histories ranging from none to mild trauma; one 26-year-old man was not osteopenic and had severe trauma. In all cases, routine radiographs were interpreted as negative, but tomography demonstrated a fracture. Five fractures were subchondral. Bone scans in 2 patients were positive. The authors conclude that osteopenic patients with a painful effusion of the knee should be considered to have an occult fracture. While bone scans may be helpful, tomography is recommended as the procedure of choice to define the location and extent of the fracture.

Apple, J.S.; Martinez, S.; Allen, N.B.; Caldwell, D.S.; Rice, J.R.

1983-08-01T23:59:59.000Z

299

Self-potential observations during hydraulic fracturing  

SciTech Connect

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

Moore, Jeffrey R.; Glaser, Steven D.

2007-09-13T23:59:59.000Z

300

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

DOE Green Energy (OSTI)

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

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

2009-03-30T23:59:59.000Z

Note: This page contains sample records for the topic "natural fracture detection" 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

NETL: Oil & Natural Gas Projects  

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

& Natural Gas Projects & Natural Gas Projects Exploration and Production Technologies Risk Based Data Management System (RBDMS) and Cost Effective Regulatory Approaches (CERA) Related to Hydraulic Fracturing and Geologic Sequestration of CO2 Last Reviewed 12/24/2013 DE-FE0000880 Goal The goal of this project is to enhance the Risk Based Data Management System (RBDMS) by adding new components relevant to environmental topics associated with hydraulic fracturing (HF), and by management of myriad data regarding oil and natural gas well histories, brine disposal, production, enhanced recovery, reporting, stripper wells, and other operations to enhance the protection of ground water resources. The FracFocus website will be maintained to ensure transparent reporting of HF additives. A

302

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 results in early water breakthroughs, reduced tertiary recovery efficiency due to channeling of injected gas or fluids, dynamic calculations of recoverable hydrocarbons that are much less than static mass balance ones due to reservoir compartmentalization, and dramatic production changes due to changes in reservoir pressure as fractures close down as conduits. These often lead to reduced ultimate recoveries or higher production costs. Generally, modeling flow behavior and mass transport in fractured porous media is done using the dual-continuum concept in which fracture and matrix are modeled as two separate kinds of continua occupying the same control volume (element) in space. This type of numerical model cannot reproduce many commonly observed types of fractured reservoir behavior since they do not explicitly model the geometry of discrete fractures, solution features, and bedding that control flow pathway geometry. This inaccurate model of discrete feature connectivity results in inaccurate flow predictions in areas of the reservoir where there is not good well control. Discrete Fracture Networks (DFN) model has been developed to aid is solving some of these problems experienced by using the dual continuum models. The Discrete Fracture Networks (DFN) approach involves analysis and modeling which explicitly incorporates the geometry and properties of discrete features as a central component controlling flow and transport. DFN are stochastic models of fracture architecture that incorporate statistical scaling rules derived from analysis of fracture length, height, spacing, orientation, and aperture. This study is focused on developing a methodology for application of DFN to a shale gas reservoir and the practical application of DFN simulator (FracGen and NFflow) for fracture modeling of a shale gas reservoir and also studies the interaction of the different fracture properties on reservoir response. The most important results of the study are that a uniform fracture network distribution and fracture aperture produces the highest cumulative gas production for the different fracture networks and fracture/well properties considered.

Ogbechie, Joachim Nwabunwanne

2011-12-01T23:59:59.000Z

303

Brittle fracture phenomena: An hypothesis  

SciTech Connect

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

Britton, K.; Walton, O.R.

1987-05-01T23:59:59.000Z

304

Incorporating Rigorous Height Determination into Unified Fracture Design  

E-Print Network (OSTI)

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

Pitakbunkate, Termpan

2010-08-01T23:59:59.000Z

305

Effective-stress-law behavior of Austin chalk rocks for deformation and fracture conductivity  

SciTech Connect

Austin chalk core has been tested to determine the effective law for deformation of the matrix material and the stress-sensitive conductivity of the natural fractures. For deformation behavior, two samples provided data on the variations of the poroelastic parameter, {alpha}, for Austin chalk, giving values around 0.4. The effective-stress-law behavior of a Saratoga limestone sample was also measured for the purpose of obtaining a comparison with a somewhat more porous carbonate rock. {alpha} for this rock was found to be near 0.9. The low {alpha} for the Austin chalk suggests that stresses in the reservoir, or around the wellbore, will not change much with changes in pore pressure, as the contribution of the fluid pressure is small. Three natural fractures from the Austin chalk were tested, but two of the fractures were very tight and probably do not contribute much to production. The third sample was highly conductive and showed some stress sensitivity with a factor of three reduction in conductivity over a net stress increase of 3000 psi. Natural fractures also showed a propensity for permanent damage when net stressed exceeded about 3000 psi. This damage was irreversible and significantly affected conductivity. {alpha} was difficult to determine and most tests were inconclusive, although the results from one sample suggested that {alpha} was near unity.

Warpinski, N.R.; Teufel, L.W.

1994-08-01T23:59:59.000Z

306

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

SciTech Connect

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

307

Optimizing reservoir management through fracture modeling  

DOE Green Energy (OSTI)

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

Renner, J.L.

1988-01-01T23:59:59.000Z

308

Mechanisms and impact of damage resulting from hydraulic fracturing. Topical report, May 1995-July 1996  

Science Conference Proceedings (OSTI)

This topical report documents the mechanisms of formation damage following hydraulic fracturing and their impact upon gas well productivity. The categories of damage reviewed include absolute or matrix permeability damage, relative permeability alterations, the damage of natural fracture permeability mechanisms and proppant conductivity impairment. Case studies are reviewed in which attempts are made to mitigate each of the damage types. Industry surveys have been conducted to determine the perceptions of the industry on the topic of formation damage following hydraulic fracturing and to identify key formations in which formation damage is a problem. From this information, technical hurdles and new technology needs are identified and estimates are made of the benefits of developing and applying minimum formation damage technology.

Penny, G.S.; Conway, M.W.; Almond, S.W.; Himes, R.; Nick, K.E.

1996-08-01T23:59:59.000Z

309

Statistical analysis of liquid seepage in partially saturated heterogeneous fracture systems  

Science Conference Proceedings (OSTI)

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

Liou, T.S.

1999-12-01T23:59:59.000Z

310

Does hydraulic-fracturing theory work in jointed rock masses  

DOE Green Energy (OSTI)

The hypocenter locations of micro-earthquakes (acoustic emissions) generated during fracturing typically are distributed three-dimensionally suggesting that fracturing stimulates a volumetric region, rather than the planar fracture theoretically expected. The hypocenter maps generated at six operating, or potential, HDR reservoirs in the US, Europe and Japan are examined in detail and the fracture dimensions are correlated with fracture injection volumes and formation permeability. Depsite the volumetric appearance of the maps we infer that the induced fractures are mainly planar and may propagate aseismically. The induced seismicity stems from nearby joints, which are not opened significantly by fracturing, but are caused to shear-slip because of local pore pressure.

Murphy, H.D.; Keppler, H.; Dash, Z.V.

1983-01-01T23:59:59.000Z

311

Well fracturing method using liquefied gas as fracturing fluid  

SciTech Connect

A method is described for fracturing an oil well or gas well with a mixture of liquid carbon dioxide and liquid petroleum gas. The objective is to be able to inject the liquid into the well bore at a relatively high pumping rate without causing the liquid to boil. Prior to injection, both the liquid CO/sub 2/ and the LPG are held in separate supply tanks at a temperature and pressure at which the liquid phase will not boil. The temperature of the LPG is substantially higher than the liquid CO/sub 2/. During the pumping operation, part of the liquid CO/sub 2/ and all of the LPG are fed through a heat exchanger. In the exchanger, the amount of heat transferred from the LPG to the liquid CO/sub 2/ is enough to vaporize the liquid. The CO/sub 2/ vapor is then circulated back into the CO/sub 2/ tank. The recycled vapor thus maintains the liquid-vapor phase in the tank at equilibrium, so that the liquid will not boil at the desired pumping rate. (4 claims)

Zingg, W.M.; Grassman, D.D.

1974-10-22T23:59:59.000Z

312

Physical model of a fractured reservoir | Open Energy Information  

Open Energy Info (EERE)

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

313

Method of optimizing the conductivity of a propped fractured formation  

Science Conference Proceedings (OSTI)

This patent describes a method of reducing viscosity of a fracturing fluid containing proppant, a polymer, a delayed breaker and a nondelayed breaker, it comprises: introducing the fracturing fluid into a subterranean formation to form at least one fracture; depositing the proppant and the polymer in the fracture; determining an after closure polymer viscosity of the deposited polymer in the fracture; selecting a proppant pack permeability in the fracture; calculating an amount of breaker necessary to reduce the after closure viscosity of the deposited polymer to attain the selected permeability of; determining a minimum viscosity of the fracturing fluid which maintains the proppant in suspension in the fluid during pumping in the fracture; and introducing an effective amount of delayed breaker and nondelayed breaker into the fracturing fluid to attain the selected proppant pack permeability while maintaining the minimum viscosity to maintain the proppant in suspension in the fluid during pumping in the fracture.

Brannon, H.D.; Gulbis, J.; King, M.T.; Hawkins, G.W.

1992-04-14T23:59:59.000Z

314

Domain Decomposition for Flow in Porous Media with Fractures  

E-Print Network (OSTI)

this article. The fractures that we are concerned with are filled with debris so we consider them as porous media. The permeability in the fracture is large in comparison with that in the surrounding rock, so the fluid circulates faster in the fracture. Thus we have a highly heterogeneous porous medium. One idea that has been used to take this into account is to treat the fracture as an interface and to assume that the fluid that flows into the fracture stays in the fracture. In fact, in many models the contrast in permeabilities is of such an order that the flow outside of the fracture is neglected. However, here we are concerned with the situation in which the exchange between the fracture and the rest of the domain is significant. To deal with this case we need to model both what happens in the fracture and what happens outside the fracture. One

Clarisse Alboin; Jerome Jaffre; Jean Roberts; Christophe Serres

1999-01-01T23:59:59.000Z

315

Corporate bodies and chemical bonds : an STS analysis of natural gas development in the United States  

E-Print Network (OSTI)

Natural gas extraction in the United States in the early 21st century has transformed social, physical, legal and biological landscapes. The technique of hydraulic fracturing, which entails the high-pressure injection into ...

Wylie, Sara Ann

2011-01-01T23:59:59.000Z

316

A Study of Latrogenic Fracture Risk in Reduction of Pipkin Fracture ...  

Science Conference Proceedings (OSTI)

This study evaluated the risk of such fractures during closed reduction of Pipkin ... of Ti-6Al-4V for Medical Applications after Surface Modification by Anodization.

317

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

318

Definition: Hydraulic Fracturing | Open Energy Information  

Open Energy Info (EERE)

Jump to: navigation, search Dictionary.png Hydraulic Fracturing The process used in the Oil and Gas industry of drilling deep into the ground and injecting water, sand, and other...

319

Multiphase flow in fractured porous media  

Science Conference Proceedings (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

320

On Water Flow in Hot Fractured Rock -- A Sensitivity Study on the Impact of Fracture-Matrix Heat Transfer  

E-Print Network (OSTI)

of multiphase, multicomponent fluid mixtures in porous andmultiphase heat and mass flow in unsaturated fractured porous

Birkholzer, Jens T.; Zhang, Yingqi

2005-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "natural fracture detection" 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

Visualization and simulation of immiscible displacement in fractured systems using micromodels: Steam injection  

SciTech Connect

A study of steam and hot water injection processes in micromodel geometries that mimic a matrix-fracture system was undertaken. The followings were observed: Light components existing in the crude oil generated a very high efficient gas-drive at elevated temperatures. This gas generation in conjunction with natural surfactant existing in the crude oil, lead to the formation of a foam in the fracture and to improved displacement in the matrix. We observed that the steam enters the fracture and the matrix depending on whether the steam rate exceeds or not the critical values. The resulting condensed water also moves preferentially into the matrix or the fracture depending on the corresponding capillary number. Since steam is a non-wetting phase as a vapor, but becomes a wetting phase when condensed in a water-wet system, steam injection involves both drainage and imbibition. It was found that all of the oil trapped by the condensed water can be mobilized and recovered when in contact with steam. We also examined hot-water displacement. In comparison with cold-water experiments at the same capillary number, a higher sweep efficiency for both light and heavy oils was observed. It was found that the loam generated in the fracture during hot-water injection, is more stable than in steamflooding. Nonetheless, hot-water injection resulted into less efficient displacement in its absence.

Yortsos, Y.C.

1995-07-01T23:59:59.000Z

322

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

SciTech Connect

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

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

1997-09-01T23:59:59.000Z

323

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

SciTech Connect

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

Costain, J.K.

2000-07-25T23:59:59.000Z

324

Hydraulic fracturing and propping tests at Yakedake field in Japan  

DOE Green Energy (OSTI)

Hydraulic fracturing experiments have been conducted at Yakedake field in Gifu prefecture, Japan. From the data obtained during the fracturing operation, the open-hole section permeability was estimated of the wellbore, the minimum pressure required to propagate the fracture, the impedances before and after the propping, and the earth stress normal to the fracture plane. The final fracture plane was also mapped with the microseismic events.

Yamaguchi, Tsutomu; Seo, Kunio; Suga, Shoto; Itoh, Toshinobu; Kuriyagawa, Michio

1984-01-01T23:59:59.000Z

325

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

SciTech Connect

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

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

2012-01-01T23:59:59.000Z

326

Poroelastic response of orthotropic fractured porous media  

SciTech Connect

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

Berryman, J.G.

2010-12-01T23:59:59.000Z

327

DETECTION OF KNOWN AND UNKNOWN NATURALLY ...  

Science Conference Proceedings (OSTI)

... contaminants. The predominant sources of halogenated secondary metabolites are sponges, algae and cyanobacteria. ...

328

Optimal fracture treatment design for dry gas wells maximizes well performance in the presence of non-Darcy flow effects  

E-Print Network (OSTI)

This thesis presents a methodology based on Proppant Number approach for optimal fracture treatment design of natural gas wells considering non-Darcy flow effects in the design process. Closure stress is taken into account, by default, because it is the first factor decreasing propped pack permeability at in-situ conditions. Gel damage was also considered in order to evaluate the impact of incorporating more damaging factors on ultimate well performance and optimal geometry. Effective fracture permeability and optimal fracture geometry are calculated through an iterative process. This approach was implemented in a spreadsheet. Non-Darcy flow is described by the ? factor. All ? factor correlations available in the literature were evaluated. It is recommended to use the correlation developed specifically for the given type of proppant and mesh size, if available. Otherwise, the Pursell et al. or the Martins et al. equations are recommended as across the board reliable correlations for predicting non-Darcy flow effects in the propped pack. The proposed methodology was implemented in the design of 11 fracture treatments of 3 natural tight gas wells in South Texas. Results show that optimal fracture design might increase expected production in 9.64 MMscf with respect to design that assumes Darcy flow through the propped pack. The basic finding is that for a given amount of proppant shorter and wider fractures compensate the non-Darcy and/or gel damage effect. Dynamic programming technique was implemented in design of multistage fractures for one of the wells under study for maximizing total gas production. Results show it is a powerful and simple technique for this application. It is recommended to expand its use in multistage fracture designs.

Lopez Hernandez, Henry De Jesus

2004-08-01T23:59:59.000Z

329

Natural Gas  

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

The Energy Department supports research and policy options to ensure environmentally sustainable domestic and global supplies of oil and natural gas.

330

Electrical Resistivity as an Indicator of Saturation in Fractured Geothermal Reservoir Rocks: Experimental Data and Modeling  

DOE Green Energy (OSTI)

The electrical resistivity of rock cores under conditions representative of geothermal reservoirs is strongly influenced by the state and phase (liquid/vapor) of the pore fluid. In fractured samples, phase change (vaporization/condensation) can result in resistivity changes that are more than an order of magnitude greater than those measured in intact samples. These results suggest that electrical resistivity monitoring of geothermal reservoirs may provide a useful tool for remotely detecting the movement of water and steam within fractures, the development and evolution of fracture systems and the formation of steam caps. We measured the electrical resistivity of cores of welded tuff containing fractures of various geometries to investigate the resistivity contrast caused by active boiling and to determine the effects of variable fracture dimensions and surface area on water extraction from the matrix. We then used the Nonisothermal Unsaturated Flow and Transport model (NUFT) (Nitao, 1998) to simulate the propagation of boiling fronts through the samples. The simulated saturation profiles combined with previously reported measurements of resistivity-saturation curves allow us to estimate the evolution of the sample resistivity as the boiling front propagates into the rock matrix. These simulations provide qualitative agreement with experimental measurements suggesting that our modeling approach may be used to estimate resistivity changes induced by boiling in more complex systems.

Detwiler, R L; Roberts, J J

2003-06-23T23:59:59.000Z

331

Modeling interfacial fracture in Sierra.  

SciTech Connect

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

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

2013-09-01T23:59:59.000Z

332

Higher-Order Compositional Modeling of Three-phase Flow in 3D Fractured Porous Media Using Cross-flow Equilibrium Approach  

E-Print Network (OSTI)

Numerical simulation of multiphase compositional flow in fractured porous media, when all the species can transfer between the phases, is a real challenge. Despite the broad applications in hydrocarbon reservoir engineering and hydrology, a compositional numerical simulator for three-phase flow in fractured media has not appeared in the literature, to the best of our knowledge. In this work, we present a three-phase fully compositional simulator for fractured media, based on higher-order finite element methods. To achieve computational efficiency, we invoke the cross-flow equilibrium (CFE) concept between discrete fractures and a small neighborhood in the matrix blocks. We adopt the mixed hybrid finite element (MHFE) method to approximate convective Darcy fluxes and the pressure equation. This approach is the most natural choice for flow in fractured media. The mass balance equations are discretized by the discontinuous Galerkin (DG) method, which is perhaps the most efficient approach to capture physical dis...

Moortgat, Joachim

2013-01-01T23:59:59.000Z

333

ACOUSTIC DETECTING AND LOCATING GAS PIPE LINE INFRINGEMENT  

Science Conference Proceedings (OSTI)

The extensive network of high-pressure natural gas transmission pipelines covering the United States provides an important infrastructure for our energy independence. Early detection of pipeline leaks and infringements by construction equipment, resulting in corrosion fractures, presents an important aspect of our national security policy. The National Energy Technology Laboratory Strategic Center for Natural Gas (SCVG) is and has been funding research on various applicable techniques. The WVU research team has focused on monitoring pipeline background acoustic signals generated and transmitted by gas flowing through the gas inside the pipeline. In case of a pipeline infringement, any mechanical impact on the pipe wall, or escape of high-pressure gas, generates acoustic signals traveling both up and down stream through the gas. Sudden changes in flow noise are detectable with a Portable Acoustic Monitoring Package (PAMP), developed under this contract. It incorporates a pressure compensating microphone and a signal- recording device. Direct access to the gas inside the line is obtained by mounting such a PAMP, with a 1/2 inch NPT connection, to a pipeline pressure port found near most shut-off valves. An FFT of the recorded signal subtracted by that of the background noise recorded one-second earlier appears to sufficiently isolate the infringement signal to allow source interpretation. Using cell phones for data downloading might allow a network of such 1000-psi rated PAMP's to acoustically monitor a pipeline system and be trained by neural network software to positively identify and locate any pipeline infringement.

John L. Loth; Gary J. Morris; George M. Palmer; Richard Guiler; Patrick Browning

2004-12-01T23:59:59.000Z

334

ACOUSTIC DETECTING AND LOCATING GAS PIPE LINE INFRINGEMENT  

Science Conference Proceedings (OSTI)

The extensive network of high-pressure natural gas transmission pipelines covering the United States provides an important infrastructure for our energy independence. Early detection of pipeline leaks and infringements by construction equipment, resulting in corrosion fractures, presents an important aspect of our national security policy. The National Energy Technology Laboratory Strategic Center for Natural Gas (SCVG) is and has been funding research on various applicable techniques. The WVU research team has focused on monitoring pipeline background acoustic signals generated and transmitted by gas flowing through the gas inside the pipeline. In case of a pipeline infringement, any mechanical impact on the pipe wall, or escape of high-pressure gas, generates acoustic signals traveling both up and down stream through the gas. Sudden changes in flow noise are detectable with a Portable Acoustic Monitoring Package (PAMP), developed under this contract. It incorporates a pressure compensating microphone and a signal- recording device. Direct access to the gas inside the line is obtained by mounting such a PAMP, with a 1/2 inch NPT connection, to a pipeline pressure port found near most shut-off valves. An FFT of the recorded signal subtracted by that of the background noise recorded one-second earlier appears to sufficiently isolate the infringement signal to allow source interpretation. Using cell phones for data downloading might allow a network of such 1000-psi rated PAMP's to acoustically monitor a pipeline system and be trained by neural network software to positively identify and locate any pipeline infringement.

John L. Loth; Gary J. Morris; George M. Palmer; Richard Guiler; Patrick Browning

2004-10-31T23:59:59.000Z

335

UNPERMITTED INJECTION OF DIESEL FUELS THROUGH HYDRAULIC FRACTURING IS A VIOLATION...  

E-Print Network (OSTI)

Thank you for the opportunity to provide comments on the Environmental Protection Agency’s (“EPA”) development of UIC Class II permitting guidance for hydraulic fracturing activities that use diesel fuels in fracturing fluids. The Natural Resources Defense Council (“NRDC”) is a national, non-profit legal and scientific organization with 1.3 million members and activists worldwide. Since its founding in 1970, NRDC has been active on a wide range of environmental issues, including fossil fuel extraction and drinking water protection. NRDC is actively engaged in issues surrounding oil and gas development and hydraulic fracturing, particularly in the Rocky Mountain West and Marcellus Shale regions. Earthjustice is a non-profit public interest law firm originally founded in 1971. Earthjustice works to protect natural resources and the environment, and to defend the right of all people to a healthy environment. Earthjustice is actively addressing threats to air, water, public health and wildlife from oil and gas development and hydraulic fracturing in the Marcellus Shale and Rocky Mountain regions. Founded in 1892, the Sierra Club works to protect communities, wild places, and the planet itself. With 1.4 million members and activists worldwide, the Club works to provide healthy communities in which to live, smart energy solutions to combat global warming, and an enduring legacy of for America’s wild

Ariel Rios Building

2011-01-01T23:59:59.000Z

336

Identifying Fracture Types and Relative Ages Using Fluid Inclusion Stratigraphy  

DOE Green Energy (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

337

NATURAL GAS FROM SHALE: Questions and Answers  

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

Representation of common equipment at a natural gas hydraulic fracturing drill pad. Representation of common equipment at a natural gas hydraulic fracturing drill pad. How is Shale Gas Produced? Shale gas formations are "unconventional" reservoirs - i.e., reservoirs of low "permeability." Permeability refers to the capacity of a porous, sediment, soil - or rock in this case - to transmit a fluid. This contrasts with a "conventional" gas reservoir produced from sands and carbonates (such as limestone). The bottom line is that in a conventional reservoir, the gas is in interconnected pore spaces, much like a kitchen sponge, that allow easier flow to a well; but in an unconventional reservoir, like shale, the reservoir must be mechanically "stimulated" to

338

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

Science Conference Proceedings (OSTI)

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

Herlé Mercier; Kevin G. Speer

1998-05-01T23:59:59.000Z

339

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

340

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

Note: This page contains sample records for the topic "natural fracture detection" 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

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

342

A triple-continuum approach for modeling flow and transport processes in fractured rock  

E-Print Network (OSTI)

Multiphase Tracer Transport in Heterogeneous Fractured Porousmultiphase, nonisothermal flow and solute transport in fractured porousmultiphase fluid flow, heat transfer, and chemical migration in a fractured porous

Wu, Yu-Shu; Liu, H.H.; Bodvarsson, G.S; Zellmer, K .E.

2001-01-01T23:59:59.000Z

343

Introducing a Clinical Practice Guideline Using Early CT in the Diagnosis of Scaphoid and Other Fractures  

E-Print Network (OSTI)

61-6. 30. Kusano N. Diagnosis of Occult Scaphoid Fracture: AMJ, Schaefer-Prokop C, et al. Occult scaphoid fractures:revealing radiographically occult scaphoid fractures. [see

2009-01-01T23:59:59.000Z

344

A PKN Hydraulic Fracture Model Study and Formation Permeability Determination  

E-Print Network (OSTI)

Hydraulic fracturing is an important method used to enhance the recovery of oil and gas from reservoirs, especially for low permeability formations. The distribution of pressure in fractures and fracture geometry are needed to design conventional and unconventional hydraulic fracturing operations, fracturing during water-flooding of petroleum reservoirs, shale gas, and injection/extraction operation in a geothermal reservoir. Designing a hydraulic fracturing job requires an understanding of fracture growth as a function of treatment parameters. There are various models used to approximately define the development of fracture geometry, which can be broadly classified into 2D and 3D categories. 2D models include, the Perkins-Kern-Nordgren (PKN) fracture model, and the Khristianovic-Geertsma-de. Klerk (KGD) fracture model, and the radial model. 3D models include fully 3D models and pseudo-three-dimensional (P-3D) models. The P-3D model is used in the oil industry due to its simplification of height growth at the wellbore and along the fracture length in multi-layered formations. In this research, the Perkins-Kern-Nordgren (PKN) fracture model is adopted to simulate hydraulic fracture propagation and recession, and the pressure changing history. Two different approaches to fluid leak-off are considered, which are the classical Carter's leak-off theory with a constant leak-off coefficient, and Pressure-dependent leak-off theory. Existence of poroelastic effect in the reservoir is also considered. By examining the impact of leak-off models and poroelastic effects on fracture geometry, the influence of fracturing fluid and rock properties, and the leak-off rate on the fracture geometry and fracturing pressure are described. A short and wide fracture will be created when we use the high viscosity fracturing fluid or the formation has low shear modulus. While, the fracture length, width, fracturing pressure, and the fracture closure time increase as the fluid leak-off coefficient is decreased. In addition, an algorithm is developed for the post-fracture pressure-transient analysis to calculate formation permeability. The impulse fracture pressure transient model is applied to calculate the formation permeability both for the radial flow and linear fracture flow assumption. Results show a good agreement between this study and published work.

Xiang, Jing

2011-12-01T23:59:59.000Z

345

Natural gas  

E-Print Network (OSTI)

www.eia.gov Over time the electricity mix gradually shifts to lower-carbon options, led by growth in natural gas and renewable generation U.S. electricity net generation trillion kilowatthours 6

Adam Sieminski Administrator; Adam Sieminski Usnic; Adam Sieminski Usnic

2013-01-01T23:59:59.000Z

346

Natural Gas  

U.S. Energy Information Administration (EIA)

Natural Gas. Under the baseline winter weather scenario, EIA expects end-of-October working gas inventories will total 3,830 billion cubic feet (Bcf) and end March ...

347

Natural Energy  

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

originate? I need to give the intitial natural source of this energy. Replies: The energy source for most known organisms is the sun. Some organisms, such as deep-sea vent fauna...

348

Anomalous fracture-extension pressure in granitic rocks  

DOE Green Energy (OSTI)

Fracture-extension pressures appreciably higher than the least principal earth-stress were observed in hydraulic fractures formed in a pair of 3 km (9600 ft) deep boreholes drilled near the Valles Caldera in northern New Mexico. Pressurization of open wellbores in rock containing preexisting fractures may open these fractures, instead of creating new fractures at right angles to the least principal stress. The pressure necessary to flow into these fractures may be appreciably higher than the least principal stress. Upon sand-propping one such pre-existing fracture, a lower fracture extension pressure was observed. A second fracture in a parallel well-bore 92 m (300 ft) away, at the same depth of 2 km (6500 ft) exhibited the lower fracture extension pressure without propping, but with about 90/sup 0/ difference in fracture direction. Fractures created through perforations at a depth of 3 km (9600 ft) not only exhibited breakdown pressures upon initial pressurization, but sometimes even higher ''breakdown'' pressures upon repressurization. These phenomena may be of interest in the interpretation of earth stress measurements made by hydraulic fracturing.

Aamodt, R.L.; Potter, R.M.

1978-01-01T23:59:59.000Z

349

Fracture Characterization Technologies | Open Energy Information  

Open Energy Info (EERE)

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

350

An Integrated Approach to Characterizing Bypassed Oil in Heterogeneous and Fractured Reservoirs Using Partitioning Tracers  

SciTech Connect

We explore the use of efficient streamline-based simulation approaches for modeling and analysis partitioning interwell tracer tests in heterogeneous and fractured hydrocarbon reservoirs. We compare the streamline-based history matching techniques developed during the first two years of the project with the industry standard assisted history matching. We enhance the widely used assisted history matching in two important aspects that can significantly improve its efficiency and effectiveness. First, we utilize streamline-derived analytic sensitivities to relate the changes in reservoir properties to the production response. These sensitivities can be computed analytically and contain much more information than that used in the assisted history matching. Second, we utilize the sensitivities in an optimization procedure to determine the spatial distribution and magnitude of the changes in reservoir parameters needed to improve the history-match. By intervening at each iteration during the optimization process, we can retain control over the history matching process as in assisted history matching. This allows us to accept, reject, or modify changes during the automatic history matching process. We demonstrate the power of our method using two field examples with model sizes ranging from 10{sup 5} to 10{sup 6} grid blocks and with over one hundred wells. We have also extended the streamline-based production data integration technique to naturally fractured reservoirs using the dual porosity approach. The principal features of our method are the extension of streamline-derived analytic sensitivities to account for matrix-fracture interactions and the use of our previously proposed generalized travel time inversion for history matching. Our proposed workflow has been demonstrated by using both a dual porosity streamline simulator and a commercial finite difference simulator. Our approach is computationally efficient and well suited for large scale field applications in naturally fractured reservoirs with changing field conditions. This considerably broadens the applicability of the streamline-based analysis of tracer data and field production history for characterization of heterogeneous and fractured reservoirs.

Akhil Datta-Gupta

2005-08-01T23:59:59.000Z

351

On the fracture toughness of advanced materials  

Science Conference Proceedings (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

352

Gas condensate damage in hydraulically fractured wells  

E-Print Network (OSTI)

This project is a research into the effect of gas condensate damage in hydraulically fractured wells. It is the result of a problem encountered in producing a low permeability formation from a well in South Texas owned by the El Paso Production Company. The well was producing from a gas condensate reservoir. Questions were raised about whether flowing bottomhole pressure below dewpoint would be appropriate. Condensate damage in the hydraulic fracture was expected to be of significant effect. In the most recent work done by Adedeji Ayoola Adeyeye, this subject was studied when the effects of reservoir depletion were minimized by introduction of an injector well with fluid composition the same as the original reservoir fluid. He also used an infinite conductivity hydraulic fracture along with a linear model as an adequate analogy. He concluded that the skin due to liquid build-up is not enough to prevent lower flowing bottomhole pressures from producing more gas. This current study investigated the condensate damage at the face of the hydraulic fracture in transient and boundary dominated periods when the effects of reservoir depletion are taken into account. As a first step, simulation of liquid flow into the fracture was performed using a 2D 1-phase simulator in order to help us to better understand the results of gas condensate simulation. Then during the research, gas condensate models with various gas compositions were simulated using a commercial simulator (CMG). The results of this research are a step forward in helping to improve the management of gas condensate reservoirs by understanding the mechanics of liquid build-up. It also provides methodology for quantifying the condensate damage that impairs linear flow of gas into the hydraulic fracture.

Reza, Rostami Ravari

2004-08-01T23:59:59.000Z

353

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

Science Conference Proceedings (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

354

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

355

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

356

DOE's Shale Gas and Hydraulic Fracturing Research | Department...  

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

DOE's Shale Gas and Hydraulic Fracturing Research DOE's Shale Gas and Hydraulic Fracturing Research April 26, 2013 - 11:05am Addthis Statement of Guido DeHoratiis Acting Deputy...

357

Permeability Estimation From Velocity Anisotropy In Fractured Rock  

E-Print Network (OSTI)

Cracks in a rock mass subjected to a uniaxial stress will be preferentially closed depending on the angle between the fracture normal vectors and the direction of the applied stress. If the prestress fracture orientation ...

Gibson, Richard L., Jr.

1990-01-01T23:59:59.000Z

358

Rigid-body fracture sound with precomputed soundbanks  

Science Conference Proceedings (OSTI)

We propose a physically based algorithm for synthesizing sounds synchronized with brittle fracture animations. Motivated by laboratory experiments, we approximate brittle fracture sounds using time-varying rigid-body sound models. We extend methods for ...

Changxi Zheng; Doug L. James

2010-07-01T23:59:59.000Z

359

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

SciTech Connect

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

360

Natural System  

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

Natural System Natural System Evaluation and Tool Development - FY11 Progress Report Prepared for U.S. Department of Energy Used Fuel Disposition Program Yifeng Wang (SNL) Michael Simpson (INL) Scott Painter (LANL) Hui-Hai Liu (LBNL) Annie B. Kersting (LLNL) July 15, 2011 FCRD-USED-2011-000223 UFD Natural System Evaluation - FY11 Year-End Report July 15, 2011 2 DISCLAIMER This information was prepared as an account of work sponsored by an agency of the U.S. Government. Neither the U.S. Government nor any agency thereof, nor any of their employees, makes any warranty, expressed or implied, or assumes any legal liability or responsibility for the accuracy, completeness, or usefulness, of any information, apparatus, product, or process disclosed, or represents that its use would not infringe

Note: This page contains sample records for the topic "natural fracture detection" 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

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

Open Energy Info (EERE)

Los Alamos National Laboratory Other Principal Investigators Grant Bromhal, National Energy Technology Laboratory Targets Milestones - Improve image resolution for fracture...

362

Fluid Flow in Fractured Rock: Theory and Application  

E-Print Network (OSTI)

Porous Media, Pullman, WA, July 9-18,1989, and to be published in the Proceedings Fluid Flow in Fractured

Long, J.C.S.

2012-01-01T23:59:59.000Z

363

Fracture Criterion of Discontinuous Carbon Fiber Dispersed SiC ...  

Science Conference Proceedings (OSTI)

About this Abstract. Meeting, Materials Science & Technology 2012. Symposium, Ceramic Matrix Composites. Presentation Title, Fracture Criterion of ...

364

Towards Understanding the Deformation and Fracture Behavior of ...  

Science Conference Proceedings (OSTI)

Presentation Title, Towards Understanding the Deformation and Fracture Behavior of Gas Turbine Structural Materials at Elevated Temperatures. Author(s)  ...

365

Experimental and Analytical Research on Fracture Processes in ROck  

DOE Green Energy (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

366

Fan Blade Fracture in a Welded Assembly - Programmaster.org  

Science Conference Proceedings (OSTI)

About this Abstract. Meeting, Materials Science & Technology 2013. Symposium, Failure Analysis and Prevention. Presentation Title, Fan Blade Fracture in a ...

367

Fracture and Delamination in Thin Film Si Electrodes  

Science Conference Proceedings (OSTI)

Symposium, Nanostructured Materials for Lithium Ion Batteries and for Supercapacitors. Presentation Title, Fracture and Delamination in Thin Film Si Electrodes.

368

8/10/12 Global Water Sustainability Flows Through Natural and Human Challenges --Environmental Protection 1/3eponline.com/articles/.../global-water-sustainability-flows-through-natural-and-human-challenges.aspx  

E-Print Network (OSTI)

-water-sustainability-flows-through-natural-and-human-challenges.aspx Hot Topics Electric Vehicles Global Climate Change Green Building Hydraulic Fracturing Nuclear Energy. China's crisis is daunting, though not unique: Twothirds of China's 669 cities have water shortages

369

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

SciTech Connect

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

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

1988-08-01T23:59:59.000Z

370

Ductile Fracture Handbook, Volume 1: Circumferential Throughwall Cracks  

Science Conference Proceedings (OSTI)

Over the past 10 years, the focus of fracture research related to nuclear power plants has shifted from brittle fractures to fractures of steels used for piping and vessels. This handbook developed by EPRI and Novetech Corporation is the first single-source document containing formulas for evaluating throughwall cracks in these tough ductile steels.

1989-07-01T23:59:59.000Z

371

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 to those in actual acid fracture treatments. After acid etching, fracture conductivity is measured at different closure stresses. This research work presents a systematic study to investigate the effect of temperature, rock-acid contact time and initial condition of the fracture surfaces on acid fracture conductivity in the Austin Chalk formation. While temperature and rock-acid contact are variables normally studied in fracture conductivity tests, the effect of the initial condition of the fracture surface has not been extensively investigated. The experimental results showed that there is no significant difference in acid fracture conductivity at high closure stress using smooth or rough fracture surfaces. In addition, we analyzed the mechanisms of acid etching and resulting conductivity creation in the two types of fracture surfaces studied by using surface profiles. For smooth surfaces, the mechanism of conductivity creation seems connected to uneven etching of the rock and roughness generation. For rough surfaces, acid conductivity is related to smoothing and deepening of the initial features on the sample surface than by creating more roughness. Finally, we compared the experimental results with Nirode-Kruk correlation for acid fracture conductivity.

Nino Penaloza, Andrea

2013-05-01T23:59:59.000Z

372

Efficient fracturing of all angle shaped VLSI mask pattern data  

Science Conference Proceedings (OSTI)

Fracturing (i.e., filling area by rectangles) is one of the most important tasks of an artwork system for a pattern generator. Growing chip complexity requires efficient algorithms to perform this non-trivial data transformation. In order to solve this ... Keywords: CAD for VLSI, computational geometry, coverage, dissection, exposure system, fracturing, hierarchical fracturing, pattern generator, plane sweep

Georg Pelz; Volker Meyer zu Bexten

1991-01-01T23:59:59.000Z

373

Particle-based fracture simulation on the GPU  

Science Conference Proceedings (OSTI)

In this paper, a particle-based framework is presented to simulate the fracture phenomenon in computer graphics field. First, the object is represented as discrete particles, and then we introduce the Extend Discrete Element Method (EDEM) simulation ... Keywords: CUDA, EDEM, anti-fracture mechanism, fracture

Jiangfan Ning; Huaxun Xu; Liang Zeng; Sikun Li

2011-01-01T23:59:59.000Z

374

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

375

Synthetic benchmark for modeling flow in 3D fractured media  

Science Conference Proceedings (OSTI)

Intensity and localization of flows in fractured media have promoted the development of a large range of different modeling approaches including Discrete Fracture Networks, pipe networks and equivalent continuous media. While benchmarked usually within ... Keywords: Benchmark, Fractured media, Single-phase flow, Stochastic model

Jean-Raynald De Dreuzy; GéRaldine Pichot; Baptiste Poirriez; Jocelyne Erhel

2013-01-01T23:59:59.000Z

376

Fracture analysis of the upper devonian antrim shale, Michigan basin  

Science Conference Proceedings (OSTI)

The Antrim Shale is a fractured, unconventional gas reservoir in the northern Michigan basin. Controls on gas production are poorly constrained but must depend on the fracture framework. Analyses of fracture geometry (orientation, spacing, and aperture width) were undertaken to better evaluate reservoir permeability and, hence, pathways for fluid migration. Measurements from nearly 600 fractures were made from outcrop, core, and Formation MicroScanner logs covering three members of the Antrim Shale (Norwood, Paxton, Lachine) and the Ellsworth Shale. Fracture analyses indicate pronounced reservoir anisotropy among the members. Together related with lithologic variations, this leads to unique reservoir characteristics within each member. There are two dominant fracture sets, northeast-southwest and northwest-southeast. Fracture density varies among stratigraphic intervals but always is lowest in the northwest-southeast fracture set and is greatest in the northeast-southwest fracture set. While aperture width decreases markedly with depth, subsurface variation in mean aperture width is significant. Based on fracture density and mean aperture width, the Norwood member has the largest intrinsic permeability and the Ellsworth Shale the lowest intrinsic permeability. The highest intrinsic fracture permeability in all intervals is associated with the northeast-southwest fracture set. The Norwood and Lachine members thus exhibit the best reservoir character. This information is useful in developing exploration strategies and completion practices in the Antrim Shale gas play.

Richards, J.A.; Budai, J.M.; Walter, L.M.; Abriola, L.M. (Univ. of Michigan, Ann Arbor, MI (United States))

1994-08-01T23:59:59.000Z

377

On Water Flow in Hot Fractured Rock -- A Sensitivity Study on the Impact of Fracture-Matrix Heat Transfer  

E-Print Network (OSTI)

for both liquid and heat transfer processes. In order to beprocesses in hot fractured rock with ( 1) flow channeling in fractures, (2) interface reduction in F-M heat transfer,

Birkholzer, Jens T.; Zhang, Yingqi

2005-01-01T23:59:59.000Z

378

Evaluation of fracture treatment type on the recovery of gas from the cotton valley formation  

E-Print Network (OSTI)

Every tight gas well needs to be stimulated with a hydraulic fracture treatment to produce natural gas at economic flow rates and recover a volume of gas that provides an acceptable return on investment. Over the past few decades, many different types of fracture fluids, propping agents and treatment sizes have been tried in the Cotton Valley formation. The treatment design engineer has to choose the optimum fluid, optimum proppant, optimum treatment size and make sure the optimum treatment is mixed and pumped in the field. These optimum values also depend on drilling costs, fracturing costs and other economic parameters; such as gas prices, operating costs and taxes. Using information from the petroleum literature, numerical and analytical simulators, and statistical analysis of production data, this research provides a detailed economic evaluation of the Cotton Valley wells drilled in the Elm Grove field operated by Matador Resources to determine not only the optimum treatment type, but also the optimum treatment volume as a function of drilling costs, completion costs, operating costs and gas prices. This work also provides an evaluation of well performance as a function of the fracture treatment type by reviewing production data from the Carthage and Oak Hill Cotton Valley fields in Texas and the Elm Grove field in Louisiana.

Yalavarthi, Ramakrishna

2008-12-01T23:59:59.000Z

379

NETL: Shale Gas and Other Natural Gas Projects  

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

Natural Gas Resources Natural Gas Resources Natural Gas Resources Shale Gas | Environmental | Other Natural Gas Related Resources | Completed NG Projects Project Number Project Name Primary Performer 10122-47 Predicting higher-than-average permeability zones in tight-gas sands, Piceance basin: An integrated structural and stratigraphic analysis Colorado School of Mines 10122-43 Diagnosis of Multi-Stage Fracturing in Horizontal Well by Downhole Temperature Measurement for Unconventional Oil and Gas Wells Texas A&M University 10122-42 A Geomechanical Analysis of Gas Shale Fracturing and Its Containment Texas A&M University 09122-02 Characterizing Stimulation Domains, for Improved Well Completions in Gas Shales Higgs-Palmer Technologies 09122-04 Marcellus Gas Shale Project Gas Technology Institute (GTI)

380

Natural Gas  

Gasoline and Diesel Fuel Update (EIA)

134,294 32,451 0.37 0 0.00 32 1.09 43,764 0.83 10,456 0.38 39,786 1.26 126,488 0.63 C o n n e c t i c u t Connecticut 54. Summary Statistics for Natural Gas Connecticut, 1992-1996...

Note: This page contains sample records for the topic "natural fracture detection" 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

Natural Gas  

Annual Energy Outlook 2012 (EIA)

3.91 119,251 0.60 229 7.81 374,824 7.15 2,867 0.10 189,966 6.01 915,035 4.57 O h i o Ohio 83. Summary Statistics for Natural Gas Ohio, 1992-1996 Table 1992 1993 1994 1995 1996...

382

Natural games  

E-Print Network (OSTI)

Behavior in the context of game theory is described as a natural process that follows the 2nd law of thermodynamics. The rate of entropy increase as the payoff function is derived from statistical physics of open systems. The thermodynamic formalism relates everything in terms of energy and describes various ways to consume free energy. This allows us to associate game theoretical models of behavior to physical reality. Ultimately behavior is viewed as a physical process where flows of energy naturally select ways to consume free energy as soon as possible. This natural process is, according to the profound thermodynamic principle, equivalent to entropy increase in the least time. However, the physical portrayal of behavior does not imply determinism. On the contrary, evolutionary equation for open systems reveals that when there are three or more degrees of freedom for behavior, the course of a game is inherently unpredictable in detail because each move affects motives of moves in the future. Eventually, when no moves are found to consume more free energy, the extensive-form game has arrived at a solution concept that satisfies the minimax theorem. The equilibrium is Lyapunov-stable against variation in behavior within strategies but will be perturbed by a new strategy that will draw even more surrounding resources to the game. Entropy as the payoff function also clarifies motives of collaboration and subjective nature of decision making.

Jani Anttila; Arto Annila

2011-03-05T23:59:59.000Z

383

Natural Gas  

Gasoline and Diesel Fuel Update (EIA)

0 0.00 53 1.81 147,893 2.82 7,303 0.27 93,816 2.97 398,581 1.99 W i s c o n s i n Wisconsin 97. Summary Statistics for Natural Gas Wisconsin, 1992-1996 Table 1992 1993 1994...

384

Natural Gas  

Annual Energy Outlook 2012 (EIA)

10,799 1,953 0.02 0 0.00 0 0.00 2,523 0.05 24 0.00 2,825 0.09 7,325 0.04 V e r m o n t Vermont 93. Summary Statistics for Natural Gas Vermont, 1992-1996 Table 1992 1993 1994 1995...

385

Natural Gas  

Annual Energy Outlook 2012 (EIA)

845,998 243,499 2.75 135,000 0.68 35 1.19 278,606 5.32 7,239 0.26 154,642 4.90 684,022 3.42 P e n n s y l v a n i a Pennsylvania 86. Summary Statistics for Natural Gas...

386

Experimental Determination of Tracer Dispersivity in Fractures  

DOE Green Energy (OSTI)

Reinjection of waste hot water is commonly practiced in most geothermal fields, primarily as a means of disposal. Surface discharge of these waste waters is usually unacceptable due to the resulting thermal and chemical pollution. Although reinjection can help to main reservoir pressure and fluid volume, in some cases a decrease in reservoir productivity has been observed. This is caused by rapid flow of the reinjected water through fractures connecting the injector and producers. As a result, the water is not sufficiently heated by the reservoir rock, and a reduction in enthalpy of the produced fluids is seen. Tracer tests have proven to be valuable to reservoir engineers for the design of a successful reinjection program. By injecting a slug of tracer and studying the discharge of surrounding producing wells, an understanding of the fracture network within a reservoir can be provided. In order to quantify the results of a tracer test, a model that accurately describes the mechanisms of tracer transport is necessary. One such mechanism, dispersion, is like a smearing out of a tracer concentration due to the velocity gradients over the cross section of flow. If a dispersion coefficient can be determined from tracer test data, the fracture width can be estimated. The purpose of this project was to design and construct an apparatus to study the dispersion of a chemical tracer in flow through a fracture.

Gilardi, J.; Horns, R.N.

1985-01-22T23:59:59.000Z

387

Unsteady Flow Model for Fractured Gas Reservoirs  

Science Conference Proceedings (OSTI)

Developing low permeability reservoirs is currently a big challenge to the industry. Because low permeability reservoirs are of low quality and are easily damaged, production from a single well is low, and there is unlikely to be any primary recovery. ... Keywords: Low permeability, Fractured well, Orthogonal transformation, Unsteady, Productivity

Li Yongming; Zhao Jinzhou; Gong Yang; Yao Fengsheng; Jiang Youshi

2010-12-01T23:59:59.000Z

388

Regulation of Hydraulic Fracturing (or lack thereof)  

E-Print Network (OSTI)

: "subsurface emplacement of fluids by well injection." 42 U.S.C. § 300h(d)(1). #12;UIC Program Requirements, EPA has concluded that the injection of hydraulic fracturing fluids into [coalbed methane] wells poses Water Act The federal Safe Drinking Water Act prohibits "underground injection" that is not authorized

Boufadel, Michel

389

Mixing in the Romanche Fracture Zone  

Science Conference Proceedings (OSTI)

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

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

1998-10-01T23:59:59.000Z

390

GEOLOGY AND FRACTURE SYSTEM AT STRIPA  

E-Print Network (OSTI)

g. ~C,K iiE,30~~ nK,~K E E CoK 28S C ;~K, 70K~tC K SO C kite 50,65 C K,t Ii f ~g K CoK (XBL 799-11950 ) U K,e FRACTURE

Olkiewicz, O.

2010-01-01T23:59:59.000Z

391

Evaluation of waste disposal by shale fracturing  

SciTech Connect

The shale fracturing process is evaluated as a means for permanent disposal of radioactive intermediate level liquid waste generated at the Oak Ridge National Laboratory. The estimated capital operating and development costs of a proposed disposal facility are compared with equivalent estimated costs for alternative methods of waste fixation.

Weeren, H.O.

1976-02-01T23:59:59.000Z

392

NETL: Oil & Natural Gas Projects  

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

Low Permeability Gas Low Permeability Gas Design and Implementation of Energized Fracture Treatment in Tight Gas Sands DE-FC26-06NT42955 Goal The goal of this project is to develop methods and tools that can enable operators to design, optimize, and implement energized fracture treatments in a systematic way. The simulator that will result from this work would significantly expand the use and cost-effectiveness of energized fracs and improve their design and implementation in tight gas sands. Performer University of Texas-Austin, Austin, TX Background A significant portion of U.S. natural gas production comes from unconventional gas resources such as tight gas sands. Tight gas sands account for 58 percent of the total proved natural gas reserves in the United States. As many of these tight gas sand basins mature, an increasing number of wells are being drilled or completed into nearly depleted reservoirs. This includes infill wells, recompletions, and field-extension wells. When these activities are carried out, the reservoir pressures encountered are not as high as the initial reservoir pressures. In these situations, where pressure drawdowns can be less than 2,000 psi, significant reductions in well productivity are observed, often due to water blocking and insufficient clean-up of fracture-fluid residues. In addition, many tight gas sand reservoirs display water sensitivity—owing to high clay content—and readily imbibe water due both to very high capillary pressures and low initial water saturations.

393

Deriving the shape factor of a fractured rock matrix  

SciTech Connect

Fluid flow from a fractured rock matrix was investigated for accurately predicting oil recovery from fractured reservoirs. To relate the oil rate with rock geometry and average rock matrix pressure, a shape factor is used in the mathematical model of fractured reservoirs. The shape factor in the transfer function was derived by solving the three-dimensional diffusivity equation of a rock matrix block under unsteady-state production, in contrast to the quasi-steady-state condition assumed by most previous studies denoted in the literature. The diffusivity equation in the x, y, and z coordinate was solved in four cases by assuming different boundary conditions of (1) constant fracture pressure; (2) constant flow rate; (3) constant fracture pressure followed by linearly declining fracture pressure; and (4) linearly declining fracture pressure followed by constant fracture pressure. Shape factor values are high at the initial depletion stage under an unsteady-state condition. When the fracture pressure is constant, the shape factor converges to {pi}{sup 2}/L{sup 2}, 2{pi}{sup 2}/L{sup 2}, and 3{pi}{sup 2}/L{sup 2} for one-, two-, and three-dimensional rock matrix, respectively, at the dimensionless time ({tau}) of about 0.1. When the flow rate between the rock matrix and the fracture is constant, the fracture pressure varies with location on the rock surface. Based on the average fracture pressure, the shape factor decreases with production time until a {tau} value of 0.1 is reached. The boundary conditions of constant fracture pressure followed by a constant decline in fracture pressure are equivalent to the condition of a constant fracture pressure followed by a period of constant flow rate.

Chang, Ming-Ming

1993-09-01T23:59:59.000Z

394

STEO September 2012 - natural gas production  

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

natural gas production at record high, inventories most natural gas production at record high, inventories most ever at start of heating season on Nov. 1 U.S. marketed natural gas production is expected to rise by 2.6 billion cubic feet per day this year to a record 68.9 billion cubic feet per day, said the U.S. Energy Information Administration in its new monthly short-term energy outlook for September. EIA analyst Katherine Teller explains: "This strong growth in production was driven in large part by production in Pennsylvania's Marcellus shale formation where drilling companies are using hydraulic fracturing to free the trapped gas." The increase in production, along with the large natural gas inventories left over from last winter because of warmer temperatures, will push U.S. gas inventories to a record high of nearly

395

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

Open Energy Info (EERE)

Microseismicity, stress, and fracture in the Coso geothermal field, Microseismicity, stress, and fracture in the Coso geothermal field, California Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Journal Article: Microseismicity, stress, and fracture in the Coso geothermal field, California Details Activities (1) Areas (1) Regions (0) Abstract: Microseismicity, stress, and fracture in the Coso geothermal field are investigated using seismicity, focal mechanisms and stress analysis. Comparison of hypocenters of microearthquakes with locations of development wells indicates that microseismic activity has increased since the commencement of fluid injection and circulation. Microearthquakes in the geothermal field are proposed as indicators of shear fracturing associated with fluid injection and circulation along major pre-existing

396

Natural Gas  

Gasoline and Diesel Fuel Update (EIA)

,366 ,366 95,493 1.08 0 0.00 1 0.03 29,406 0.56 1,206 0.04 20,328 0.64 146,434 0.73 - Natural Gas 1996 Million Percent of Million Percent of Cu. Feet National Total Cu. Feet National Total Net Interstate Movements: Industrial: Marketed Production: Vehicle Fuel: Deliveries to Consumers: Electric Residential: Utilities: Commercial: Total: South Carolina South Carolina 88. Summary Statistics for Natural Gas South Carolina, 1992-1996 Table 1992 1993 1994 1995 1996 Reserves (billion cubic feet) Estimated Proved Reserves (dry) as of December 31 ....................................... 0 0 0 0 0 Number of Gas and Gas Condensate Wells Producing at End of Year.............................. 0 0 0 0 0 Production (million cubic feet) Gross Withdrawals From Gas Wells ......................................... 0 0 0 0 0 From Oil Wells ...........................................

397

Natural Gas  

Gasoline and Diesel Fuel Update (EIA)

0,216 0,216 50,022 0.56 135 0.00 49 1.67 85,533 1.63 8,455 0.31 45,842 1.45 189,901 0.95 - Natural Gas 1996 Million Percent of Million Percent of Cu. Feet National Total Cu. Feet National Total Net Interstate Movements: Industrial: Marketed Production: Vehicle Fuel: Deliveries to Consumers: Electric Residential: Utilities: Commercial: Total: M a r y l a n d Maryland 68. Summary Statistics for Natural Gas Maryland, 1992-1996 Table 1992 1993 1994 1995 1996 Reserves (billion cubic feet) Estimated Proved Reserves (dry) as of December 31 ....................................... NA NA NA NA NA Number of Gas and Gas Condensate Wells Producing at End of Year.............................. 9 7 7 7 8 Production (million cubic feet) Gross Withdrawals From Gas Wells ......................................... 33 28 26 22 135 From Oil Wells ...........................................

398

High-permeability fracturing: The evolution of a technology  

SciTech Connect

Since its introduction almost 50 years ago, hydraulic fracturing has been the prime engineering tool for improving well productivity either by bypassing near-wellbore damage or by actually stimulating performance. Historically (and in many instances erroneously), the emphasis for propped fracturing was on fracture length, culminating in massive treatments for tight-gas sands with several million pounds of proppant and design lengths in excess of 1,500 ft. More recently, the importance of fracture conductivity has become appreciated. This paper uses field examples to trace the history, development, and application of TSO fracturing to high-permeability formations, including fracturing to increase PI, as well as applications aimed at improving completions in unconsolidated sands. Potential applications of fracturing to bypass the need for sand control are explored. Finally, the use of fracturing as a reservoir-management tool is examined through use of a propped fracture to alter the vertical flow profile of a well to maximize reserves. This particular use of fracturing leads to cases where careful design of both fracture length and conductivity is required; i.e., too much conductivity is as damaging to reservoir management as too little.

Smith, M.B.; Hannah, R.R.

1996-07-01T23:59:59.000Z

399

Characterization of Fractures in Geothermal Reservoirs Using Resistivity |  

Open Energy Info (EERE)

Characterization of Fractures in Geothermal Reservoirs Using Resistivity Characterization of Fractures in Geothermal Reservoirs Using Resistivity Jump to: navigation, search OpenEI Reference LibraryAdd to library Conference Paper: Characterization of Fractures in Geothermal Reservoirs Using Resistivity Abstract The optimal design of production in fractured geothermal reservoirs requires knowledge of the resource's connectivity, therefore making fracture characterization highly important. This study aims to develop methodologies to use resistivity measurements to infer fracture properties in geothermal fields. The resistivity distribution in the field can be estimated by measuring potential differences between various points and the data can then be used to infer fracture properties due to the contrast in resistivity between water and rock.

400

Monitoring the Width of Hydraulic Fractures With Ultrasonic Measurements  

E-Print Network (OSTI)

Introduction During hydraulic fracturing experiments in the laboratory the opening of hydraulic fractures is monitored with ultrasonic transducers. The experiment closely resembles seismic monitoring surveys in the field [MEADOWS AND WIN- TERSTEIN 1994, WILLS ET AL. 1992]. The extraction of information out of these experiments is critically dependent on the understanding of the elastodynamic behaviour of the thin fluid filled fractures. The laboratory experiments provide useful information on what determines the seismic visibility of these fractures, both for compressional and shear waves. The role of the fracture thickness or width on the elastodynamic response and a new method for monitoring fracture opening is investigated. Most theoretical approaches postulate the use of the classical boundary conditions. The void boundary condition assumes a stress free surface. The "fluid-filled" fracture boundary condition

J. Groenenboom; A.J.W. Duijndam; J.T. Fokkema

1995-01-01T23:59:59.000Z

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401

Advanced hydraulic fracturing methods to create in situ reactive barriers  

Science Conference Proceedings (OSTI)

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

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

1997-12-31T23:59:59.000Z

402

Pressure oscillations caused by momentum on shut in of a high rate well in a fractured formation  

DOE Green Energy (OSTI)

Pressure transient testing techniques are an important part of reservoir and production testing procedures. These techniques are frequently used to determine practical information about underground reservoirs such as the permeability, porosity, liquid content, reservoir and liquid discontinuities and other related data. This information is valuable in helping to analyze, improve and forecast reservoir performance. This report is concerned with developing models for pressure transient well testing in high permeability, high flow rate, naturally fractured reservoirs. In the present work, a study was made of the effects of liquid inertia in the fractures and the wellbore on the pressure response obtained during a well test. The effects of turbulent flow and multi-phase flow effects such as gravitational segregation or anisotropic porous media effects were not considered. The scope of the study was limited to studying inertial effects on the pressure response of a fractured reservoir.

Bhatnagar, S.

1989-06-01T23:59:59.000Z

403

Wikipedia vandalism detection  

Science Conference Proceedings (OSTI)

Wikipedia is an online encyclopedia that anyone can access and edit. It has become one of the most important sources of knowledge online and many third party projects rely on it for a wide-range of purposes. The open model of Wikipedia allows pranksters, ... Keywords: Wikipedia vandalism detection, machine learning, natural language processing, reputation

Santiago M. Mola-Velasco

2011-03-01T23:59:59.000Z

404

Influence of orientation on fracture toughness and tensile moduli in Berkeley granite  

DOE Green Energy (OSTI)

Fracture toughness and tensile modulus values for Berkeley granite show pronounced orientation dependence. Apparent fracture toughness values (K{sub Q}) correspond to natural strong and weak planes in the rock: cracks propagated in the head grain (strongest) plane have K{sub Q} = 1.81 MPa ..sqrt..m, those grown in the rift (weakest) plane have K{sub Q} = 1.01 MPa ..sqrt..m and those in the grain (intermediate) plane have K/sub Q/ = 1.40 MPa ..sqrt..m. These directional K/sub Q/ data also correlate with tensile modulus values, E, which are 50.7 GPa,, 21.6 GPa and 39.3 GPa, respectively. An empirical relationship between K/sub Q/ and E is demonstrated. Monitoring of acoustic emission events shows promise as a detector of onset of crack growth.

Halleck, P.M.; Kumnick, A.J.

1980-01-01T23:59:59.000Z

405

A Semi-Analytic Solution for Flow in Finite-Conductivity Vertical Fractures Using Fractal Theory  

E-Print Network (OSTI)

The exploitation of unconventional reservoirs goes hand in hand with the practice of hydraulic fracturing and, with an ever increasing demand in energy, this practice is set to experience significant growth in the coming years. Sophisticated analytic models are needed to accurately describe fluid flow in a hydraulic fracture and the problem has been approached from different directions in the past 3 decades - starting with the use of line-source functions for the infinite conductivity case, followed by the application of Laplace Transforms and the Boundary-Element Method for the finite-conductivity case. This topic remains an active area of research and, for the more complicated physical scenarios such as multiple transverse fractures in ultra-tight reservoirs, answers are presently being sought. Fractal theory has been successfully applied to pressure transient testing, albeit with an emphasis on the effects of natural fractures in pressure-rate behavior. In this work, we begin by performing a rigorous analytical and numerical study of the Fractal Diffusivity Equation and we show that it is more fundamental than the classic linear and radial diffusivity equations. Subsequently, we combine the Fractal Diffusivity Equation with the Trilinear Flow Model, culminating in a new semi-analytic solution for flow in a finite-conductivity vertical fracture which we name the "Fractal-Fracture Solution". This new solution is instantaneous and has an overall accuracy of 99.7%, thus making it comparable to the Trilinear Pseudoradial Solution for practical purposes. It may be used for pressure transient testing and reservoir characterization of hydrocarbon reservoirs being produced by a vertically fractured well. Additionally, this is the first time that fractal theory is used in fluid flow in porous media to address a problem not related to reservoir heterogeneity. Ultimately, this work is a demonstration of the untapped potential of fractal theory; our approach is very flexible and we believe that the same methodology may be extended to develop new reservoir flow solutions for pressing problems that the industry currently faces.

Cossio Santizo, Manuel

2012-08-01T23:59:59.000Z

406

Natural networks  

E-Print Network (OSTI)

Scale-free and non-computable characteristics of natural networks are found to result from the least-time dispersal of energy. To consider a network as a thermodynamic system is motivated since ultimately everything that exists can be expressed in terms of energy. According to the variational principle, the network will grow and restructure when flows of energy diminish energy differences between nodes as well as relative to nodes in surrounding systems. The natural process will yield scale-free characteristics because the nodes that contribute to the least-time consumption of free energy preferably attach to each other. Network evolution is a path-dependent and non-deterministic process when there are two or more paths to consume a common source of energy. Although evolutionary courses of these non-Hamiltonian systems cannot be predicted, many mathematical functions, models and measures that characterize networks can be recognized as appropriate approximations of the thermodynamic equation of motion that has been derived from statistical physics of open systems.

Tuomo Hartonen; Arto Annila

2011-06-21T23:59:59.000Z

407

Gas condensate damage in hydraulically fractured wells  

E-Print Network (OSTI)

This project is a research into the effect of gas condensate damage in hydraulically fractured wells. It is the result of a problem encountered in producing a low permeability formation from a well in South Texas owned by the El Paso Production Company. The well was producing a gas condensate reservoir and questions were raised about how much drop in flowing bottomhole pressure below dewpoint would be appropriate. Condensate damage in the hydraulic fracture was expected to be of significant effect. Previous attempts to answer these questions have been from the perspective of a radial model. Condensate builds up in the reservoir as the reservoir pressure drops below the dewpoint pressure. As a result, the gas moving to the wellbore becomes leaner. With respect to the study by El-Banbi and McCain, the gas production rate may stabilize, or possibly increase, after the period of initial decline. This is controlled primarily by the condensate saturation near the wellbore. This current work has a totally different approach. The effects of reservoir depletion are minimized by introduction of an injector well with fluid composition the same as the original reservoir fluid. It also assumes an infinite conductivity hydraulic fracture and uses a linear model. During the research, gas condensate simulations were performed using a commercial simulator (CMG). The results of this research are a step forward in helping to improve the management of gas condensate reservoirs by understanding the mechanics of liquid build-up. It also provides methodology for quantifying the condensate damage that impairs linear flow of gas into the hydraulic fracture.

Adeyeye, Adedeji Ayoola

2003-12-01T23:59:59.000Z

408

Measurement of Effect of Chemical Reactions on the Hydrologic Properties of Fractured Glass Media Using a Tri-axial Flow and Transport Apparatus  

Science Conference Proceedings (OSTI)

Understanding the effect of chemical reactions on the hydrologic properties of sub-surface media is critical to many natural and engineered sub-surface systems. Methods and information for such characterization of fractured media are severely lacking. Influence of glass corrosion (precipitation and dissolution) reactions on fractured glass blocks HAN28 and LAWBP1, two candidate waste glass forms for a proposed immobilized low-activity waste (ILAW) disposal facility at the Hanford, WA site, was investigated. Flow and tracer transport experiments were conducted in such randomly and multiply fractured ILAW glass blocks, before and after subjecting them to corrosion using Vapor Hydration Testing (VHT) at 200 oC temperature and 200 psig (1379 KPa) pressure, causing the precipitation of alteration products. A tri-axial fractured media flow and transport experimental apparatus, which allows the simultaneous measurement of flow and transport properties and their anisotropy, has been designed and built for this purpose. Such apparatus for fractured media characterization are being reported in the literature only recently. Hydraulic properties of fractured blocks were measured in different orientations and along different cardinal directions, before and after glass corrosion reactions. Miscible displacement experiments using a non-reactive dye were also conducted, before and after glass corrosion reactions, to study the tracer transport behavior through such media. Initial efforts to analyze breakthrough curve (BTC) data using a 1D Advection Dispersion Equation (ADE) solution revealed that a different fractured media transport model may be necessary for such interpretation. It was found that glass reactions can have a significant influence on the hydrologic properties of fractured ILAW glass media. The methods and results are unique and useful to better understand the effect of chemical reactions on the hydrologic properties of fractured geomedia in general and glass media in particular.

Saripalli, Kanaka P.; Lindberg, Michael J.; Meyer, Philip D.

2006-09-15T23:59:59.000Z

409

Optimization of fractured well performance of horizontal gas wells  

E-Print Network (OSTI)

In low-permeability gas reservoirs, horizontal wells have been used to increase the reservoir contact area, and hydraulic fracturing has been further extending the contact between wellbores and reservoirs. This thesis presents an approach to evaluate horizontal well performance for fractured or unfractured gas wells and a sensitivity study of gas well performance in a low permeability formation. A newly developed Distributed Volumetric Sources (DVS) method was used to calculate dimensionless productivity index for a defined source in a box-shaped domain. The unique features of the DVS method are that it can be applied to transient flow and pseudo-steady state flow with a smooth transition between the boundary conditions. In this study, I conducted well performance studies by applying the DVS method to typical tight sandstone gas wells in the US basins. The objective is to determine the best practice to produce horizontal gas wells. For fractured wells, well performance of a single fracture and multiple fractures are compared, and the effect of the number of fractures on productivity of the well is presented based on the well productivity. The results from this study show that every basin has a unique ideal set of fracture number and fracture length. Permeability plays an important role on dictating the location and the dimension of the fractures. This study indicated that in order to achieve optimum production, the lower the permeability of the formation, the higher the number of fractures.

Magalhaes, Fellipe Vieira

2007-08-01T23:59:59.000Z

410

Dual Permeability Modeling of Flow in a Fractured Geothermal Reservoir  

DOE Green Energy (OSTI)

A three dimensional fracture system synthesis and flow simulation has been developed to correlate drawdown characteristics measured in a geothermal well and to provide the basis for an analysis of tracer tests. A new dual permeability approach was developed which incorporates simulations at two levels to better represent a discrete fracture system within computer limitations. The first incorporates a discrete simulation of the largest fractures in the system plus distributed or representative element simulation of the smaller fractures. the second determines the representative element properties by discrete simulation of the smaller fractures. The fracture system was synthesized from acoustic televiewer data on the orientation and separation of three distinct fracture sets, together with additional data from the literature. Lognormal and exponential distributions of fracture spacing and radius were studied with the exponential distribution providing more reasonable results. Hydraulic apertures were estimated as a function of distance from the model boundary to a constant head boundary. Mean values of 6.7, 101 and 46 {micro}m were chosen as the most representative values for the three fracture sets. Recommendations are given for the additional fracture characterization needed to reduce the uncertainties in the model.

Miller, John D.; Allman, David W.

1986-01-21T23:59:59.000Z

411

Dual permeability modeling of flow in a fractured geothermal reservoir  

DOE Green Energy (OSTI)

A three dimensional fracture system synthesis and flow simulation has been developed to correlate drawdown characteristics measured in a geothermal well and to provide the basis for an analysis of tracer tests. A new dual permeability approach was developed which incorporates simulations at two levels to better represent a discrete fracture system within computer limitations. The first incorporates a discrete simulation of the largest fractures in the system plus distributed or representative element stimulation of the smaller fractures. The second determines the representative element properties by discrete simulation of the smaller fractures. The fracture system was synthesized from acoustic televiewer data on the orientation and separation of three distinct fracture sets, together with additional data from the literature. Lognormal and exponential distributions of fracture spacing and radius were studied with the exponential distribution providing more reasonable results. Hydraulic apertures were estimated as a function of distance from the model boundary to a constant head boundary. Mean values of 6.7, 101 and 46 ..mu..m were chosen as the most representative values for the three fracture sets. Recommendations are given for the additional fracture characterization needed to reduce the uncertainties in the model. 20 refs., 6 figs.

Miller, J.D.; Allman, D.W.

1986-01-01T23:59:59.000Z

412

Modelling cleavage fracture of bainitic steels  

Science Conference Proceedings (OSTI)

The origin of brittle fracture of polycrystalline metals failing by cleavage is most frequently associated to slip-induced cracking of some non-metallic brittle particle or inclusion (a carbide in ferritic steels). When the size of the particles is smaller than the grain size of the metallic matrix, the nucleating event of a macroscopic failure results from the successive occurrence of three simple events: slip-induced cleavage of a particle, transmission of the microcrack to the neighboring grain across the particle/matrix interface and propagation of the grain-size microcrack to the neighboring grains across the grain boundary. On the basis of this scheme, a statistical weakest link'' fracture model has been developed which takes into account the presence of two independent distributions of structural elements (isolated particles and matrix grains) with two barriers for cleavage propagation (the particle/matrix interfaces and the grain boundaries), characterized by a crack arrest capability well over the crack propagation resistance of the cleavage planes of the crystalline lattices of the two planes. An application of the model to the prediction of the fracture stress and the critical stress intensity factor as a function of the temperature of a bainitic steel is presented.

Martin-Meizoso, A.; Ocana-Arizcorreta, I.; Gil-Sevillano, J.; Fuentes-Perez, M. (Univ. de Navarra, San Sebastian (Spain). Escuela Superior de Ingenieros Centro de Estudios e Investigaciones Tecnicas de Guipuzcoa, San Sebastian (Spain))

1994-06-01T23:59:59.000Z

413

Natural Gas from Shale  

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

Office of Fossil Energy research helped refine cost-effective horizontal drilling and hydraulic fracturing technologies, protective environmental practices and data development, making hundreds of trillions of cubic feet of gas technically recoverable where they once were not.

414

Natural Gas  

Gasoline and Diesel Fuel Update (EIA)

21,547 21,547 4,916 0.06 0 0.00 0 0.00 7,012 0.13 3 0.00 7,099 0.22 19,031 0.10 N e w H a m p s h i r e New Hampshire 77. Summary Statistics for Natural Gas New Hampshire, 1992-1996 Table 1992 1993 1994 1995 1996 Reserves (billion cubic feet) Estimated Proved Reserves (dry) as of December 31 ....................................... 0 0 0 0 0 Number of Gas and Gas Condensate Wells Producing at End of Year.............................. 0 0 0 0 0 Production (million cubic feet) Gross Withdrawals From Gas Wells ......................................... 0 0 0 0 0 From Oil Wells ........................................... 0 0 0 0 0 Total.............................................................. 0 0 0 0 0 Repressuring ................................................ 0 0 0 0 0 Nonhydrocarbon Gases Removed ............... 0 0 0 0 0 Wet After Lease Separation..........................

415

Natural Gas  

Gasoline and Diesel Fuel Update (EIA)

139,881 139,881 26,979 0.30 463 0.00 115 3.92 27,709 0.53 19,248 0.70 28,987 0.92 103,037 0.52 A r i z o n a Arizona 50. Summary Statistics for Natural Gas Arizona, 1992-1996 Table 1992 1993 1994 1995 1996 Reserves (billion cubic feet) Estimated Proved Reserves (dry) as of December 31 ....................................... NA NA NA NA NA Number of Gas and Gas Condensate Wells Producing at End of Year.............................. 6 6 6 7 7 Production (million cubic feet) Gross Withdrawals From Gas Wells ......................................... 721 508 711 470 417 From Oil Wells ........................................... 72 110 48 88 47 Total.............................................................. 794 618 759 558 464 Repressuring ................................................ 0 0 0 0 0 Nonhydrocarbon Gases Removed ............... 0 0 0 0 0 Wet After Lease

416

Natural Gas  

Gasoline and Diesel Fuel Update (EIA)

Middle Middle Atlantic Middle Atlantic 37. Summary Statistics for Natural Gas Middle Atlantic, 1992-1996 Table 1992 1993 1994 1995 1996 Reserves (billion cubic feet) Estimated Proved Reserves (dry) as of December 31 ....................................... 1,857 1,981 2,042 1,679 1,928 Number of Gas and Gas Condensate Wells Producing at End of Year.............................. 36,906 36,857 26,180 37,159 38,000 Production (million cubic feet) Gross Withdrawals From Gas Wells ......................................... 161,372 152,717 140,444 128,677 152,494 From Oil Wells ........................................... 824 610 539 723 641 Total.............................................................. 162,196 153,327 140,982 129,400 153,134 Repressuring ................................................ 0 0 0 0 0 Nonhydrocarbon Gases Removed

417

Natural Gas  

Gasoline and Diesel Fuel Update (EIA)

386,690 386,690 102,471 1.16 0 0.00 43 1.47 142,319 2.72 5,301 0.19 98,537 3.12 348,671 1.74 M i n n e s o t a Minnesota 71. Summary Statistics for Natural Gas Minnesota, 1992-1996 Table 1992 1993 1994 1995 1996 Reserves (billion cubic feet) Estimated Proved Reserves (dry) as of December 31 ....................................... 0 0 0 0 0 Number of Gas and Gas Condensate Wells Producing at End of Year.............................. 0 0 0 0 0 Production (million cubic feet) Gross Withdrawals From Gas Wells ......................................... 0 0 0 0 0 From Oil Wells ........................................... 0 0 0 0 0 Total.............................................................. 0 0 0 0 0 Repressuring ................................................ 0 0 0 0 0 Nonhydrocarbon Gases Removed ............... 0 0 0 0 0 Wet After Lease Separation..........................

418

Natural Gas  

Gasoline and Diesel Fuel Update (EIA)

1,108,583 1,108,583 322,275 3.63 298 0.00 32 1.09 538,749 10.28 25,863 0.95 218,054 6.90 1,104,972 5.52 I l l i n o i s Illinois 61. Summary Statistics for Natural Gas Illinois, 1992-1996 Table 1992 1993 1994 1995 1996 Reserves (billion cubic feet) Estimated Proved Reserves (dry) as of December 31 ....................................... NA NA NA NA NA Number of Gas and Gas Condensate Wells Producing at End of Year.............................. 382 385 390 372 370 Production (million cubic feet) Gross Withdrawals From Gas Wells ......................................... 337 330 323 325 289 From Oil Wells ........................................... 10 10 10 10 9 Total.............................................................. 347 340 333 335 298 Repressuring ................................................ 0 0 0 0 0 Nonhydrocarbon Gases Removed ...............

419

Natural Gas  

Gasoline and Diesel Fuel Update (EIA)

286,485 286,485 71,533 0.81 25 0.00 31 1.06 137,225 2.62 5,223 0.19 72,802 2.31 286,814 1.43 M i s s o u r i Missouri 73. Summary Statistics for Natural Gas Missouri, 1992-1996 Table 1992 1993 1994 1995 1996 Reserves (billion cubic feet) Estimated Proved Reserves (dry) as of December 31 ....................................... NA NA NA NA NA Number of Gas and Gas Condensate Wells Producing at End of Year.............................. 5 8 12 15 24 Production (million cubic feet) Gross Withdrawals From Gas Wells ......................................... 27 14 8 16 25 From Oil Wells ........................................... 0 0 0 0 0 Total.............................................................. 27 14 8 16 25 Repressuring ................................................ 0 0 0 0 0 Nonhydrocarbon Gases Removed ............... 0 0 0 0 0 Wet After Lease Separation..........................

420

Natural Gas  

Gasoline and Diesel Fuel Update (EIA)

411,951 411,951 100,015 1.13 0 0.00 5 0.17 114,365 2.18 45,037 1.65 96,187 3.05 355,609 1.78 Massachusetts Massachusetts 69. Summary Statistics for Natural Gas Massachusetts, 1992-1996 Table 1992 1993 1994 1995 1996 Reserves (billion cubic feet) Estimated Proved Reserves (dry) as of December 31 ....................................... 0 0 0 0 0 Number of Gas and Gas Condensate Wells Producing at End of Year.............................. 0 0 0 0 0 Production (million cubic feet) Gross Withdrawals From Gas Wells ......................................... 0 0 0 0 0 From Oil Wells ........................................... 0 0 0 0 0 Total.............................................................. 0 0 0 0 0 Repressuring ................................................ 0 0 0 0 0 Nonhydrocarbon Gases Removed ............... 0 0 0 0 0 Wet After Lease Separation..........................