21 research outputs found
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Facilitation of Science and Engineering Collaboration and Technology Transfer
Key to the success of research projects involving collaboration across disciplinary, organizational, and geographic boundaries is the use of appropriate and effective mechanisms to exchange data and analyses among research team members. Where diverse university-based research groups are also sharing data and results with industry and government collaborators and sponsors, timely and appropriate information transfer to these entities is also important to project success. Despite rapid evolution of electronic communication technologies, this data sharing and data analysis sharing function is commonly less successful than many stakeholders desire, and less effective than current technology allows. By taking advantage of a secure, interactive website environment, geoscientists, engineers, and others can communicate and share a variety of information resources effectively and conveniently. This results in closer collaboration, faster progress, lower costs, and more effective technology transfer to the private sector. However, the traditional Internet Web site, Intranet, and Extranet approaches are not solutions to many of the challenges of diverse, collaborative research teams. This report outlines the solution to this challenge developed in our project.
The project "Using Microstructure Observations To Qualify Fracture Properties and Improve Reservoir Simulation" involves multidisciplinary studies of natural fractures in hydrocarbon reservoirs by a research team of geologists and engineers at The University of Texas at Austin that is dispersed among different buildings and two different campuses. In addition, a collaborating group of industry scientists representing seven companies includes individuals located in different cities (or continents). Successful cooperative research and technology transfer for such a widely distributed group is a serious logistical and organizational challenge.Bureau of Economic Geolog
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Increasing Development Efficiency in Low-Permeability Gas Reservoirs: A Synopsis of Tight Gas Sands Project Resesarch
To support the practical application of research outcomes within the industry, this report serves as a roadmap to the literature produced by the Bureau of Economic Geology as part of the Geological Analysis of Primary and Secondary Tight Gas Sands Objectives Project under the Gas Research Institute (GRI) Tight Gas Sands Research Program from 1982 to 1992. We synthesize key findings from geological studies published in 17 GRI topical reports, over 90 Bureau of Economic Geology monographs, peer-reviewed journal articles, contributions to other GRI reports, and presentations and abstracts in conference proceedings. The purpose of this report is to provide a comprehensive index to this body of literature.
The completion of the national survey, Atlas of Major Low-Permeability Sandstone Gas Reservoirs in the Continental United States, presented an opportune moment to compile and summarize research findings spanning diverse regions, formations, and geological and engineering subjects. These findings, disseminated through publications in both geological and engineering journals, as well as GRI topical reports, are intended to be cataloged in this report.
Furthermore, this report is designed to complement the Atlas of Major Low-Permeability Sandstone Gas Reservoirs in the Continental United States, which consolidates geological, reservoir characterization, and engineering insights from 24 productive low-permeability sandstone formations across 13 basins.Bureau of Economic Geolog
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Improved Resource Characterization Technology
To enhance the application of research results by industry, this report provides a guide to the results of research carried out by the Bureau of Economic Geology in the Geological Analysis of Primary and Secondary Tight Gas Sands Objectives Project as part of the Gas Research Institute (GRI) Tight Gas Sands Research Program in the period 1982-1995. The Gas Research Institute (GRI) has supported geological investigations designed to develop the knowledge necessary to produce gas from low-permeability sandstones efficiently. As part of that program, the Bureau of Economic Geology has conducted in-depth research on most of the important low-permeability sandstones in the lower 48. Another objective was to develop advanced technologies, verified in the field, which are necessary for continued cost-competitive production from low-permeability reservoirs. An extensive body of knowledge about many aspects of the geology and engineering attributes of low-permeability sandstones has been developed. We review some of the key findings of the geologic studies published in GRI topical reports and Bureau of Economic Geology monographs, refereed journal papers, contributions to other GRI reports, and papers and abstracts in meeting transaction volumes.Bureau of Economic Geolog
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Description and interpretation of natural fracture patterns in sandstones of the Frontier Formation along the Hogsback, southwestern Wyoming
Fractures exposed in outcrop can be classified into three general groups: J1 fractures strike generally north-south and were formed early, in a regime of east-west extension during basin subsidence. These fractures have the greatest potential for extrapolation into the subsurface of the basin. J2 fractures formed during the subsequent onset of thrusting that led to the Hogsback escarpment; J2 fractures were created by a north-south dilatancy in response to east-west tectonic compression and strike generally east-west. They may extend slightly east of the thrust belt. J3 fractures formed soon after J2 fractures as a mechanical response to local shear and torsion within the thrust plate. They will not exist beyond the limits of the thrust belt. Petrographic study of selected samples suggests that the mechanical properties that controlled fracture susceptibility changed through time, dictating the potential for the sandstones to fracture during given stress-producing tectonic events.Bureau of Economic Geolog
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Fault and Joint Measurements in Austin Chalk, SuperConducting Super Collider Site, Texas
Structure maps of 9.4 miles of nearly continuous tunnel excavations and more than 10 miles of other exposures and excavations in the Austin Chalk at the Superconducting Super Collider (SSC) site in Ellis County, Texas, record normal fault and joint populations in the subsurface within the northern segment of the Balcones Fault Zone that has unmatched resolution for such a long traverse. Small faults (less than 10 feet throw) occur in clusters or swarms that have as many as 24 faults. Fault swarms are as much as 2,000 feet wide, and spacing between swarms ranges from 800 to 2,000 feet, averaging about 1,000 feet. Predominantly northeast-trending joints are in swarms spaced 500 to more than 21,000 feet apart.Bureau of Economic Geolog
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Geologic Controls on Reservoir Properties of Low Permeability Sandstone, Frontier Formation, Moxa Arch, Southwest Wyoming
This report examines the influence of stratigraphy, diagenesis, natural fractures, and in situ stress on low-permeability, gas-bearing sandstone reservoirs of the Upper Cretaceous Frontier Formation along the Moxa Arch in the Green River Basin, southwestern Wyoming. The main stratigraphic controls on distribution and quality of Frontier reservoirs are sandstone continuity and detrital clay content. The Frontier was deposited in a fluvial-deltaic system, in which most reservoirs lie in marine upper shoreface and fluvial channel-fill sandstone facies. The major causes of porosity loss in Frontier sandstones during burial diagenesis were mechanical and chemical compaction and cementation by calcite, quartz, and authigenic clays. Despite extensive diagenetic modification, reservoir quality is best in facies that had the highest porosity and permeability at the time of deposition. Natural fractures are sparse in Frontier core, but outcrop studies show that fractures commonly are in discrete, irregularly spaced swarms separated by domains having few fractures. Natural fracture swarms are potential high-permeability "sweet spots." Stress-direction indicators give highly scattered estimates of maximum horizontal compression direction ranging from north to east or northeast. The scatter may reflect interference of natural fractures with measurements of stress directions, as well as spatially variable stress directions and low horizontal stress anisotropy.Bureau of Economic Geolog
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Preliminary Geologic Description S.A. Holditch & Associates SFE No. 2
Four intervals of the Travis Peak Formation were cored in the S. A. Holditch & Associates SFE No. 2 well, North Appleby field, Nacogdoches County, Texas. Core was recovered from 8,230.0 to 8,319.7 ft, 8,678.2 to 8,738.0 ft, 9,480.0 to 9,572.1 ft, and 9,806.7 to 9,942.1 ft. The top of the Travis Peak is at 8,000 ft (log depth), so the core samples are from 230 ft to 1,942 ft below the top of the formation.Bureau of Economic Geolog
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Investigation of the Davis Sandstone (Ft. Worth Basin, Texas) as a Suitable Formation for the GRI Hydraulic Fracture Test Site
The concept of the GRI Hydraulic Fracture Test Site (HFTS) was to provide a field laboratory to (1) validate three-dimensional hydraulic fracture models in tight gas sandstone and (2) develop technology in fracture diagnostics and stimulation. The Davis sandstone in the Fort Worth Basin, north-central Texas, was initially selected as a viable candidate formation for HFTS research based on the results of a cooperative well program initiated with Dallas Production. To gather comprehensive data on a specific site for HFTS research, the S.A. Holditch & Associates Data Well No. 1 was drilled in June 1991. The results of geological, petrophysical, and engineering analyses of the co-ops and data well are the basis of this report. These analyses indicate that in northern Parker and southern Wise Counties, Texas, the Davis sediments range from 250 to 350 feet thick. A broadly continuous, 100-foot thick interval in the upper part of the gross interval comprises the Davis Reservoir. The average permeability of the Davis Reservoir was found to be 0.08 millidarcies with an average closure stress of 0.45 pounds per square inch per foot. The shale barriers above and below the Davis had average closure stress of 0.63 to 0.73 pounds per square inch per foot and 0.88 to 0.98 pounds per square inch per foot, respectively. Hydraulic fracture azimuth was found to range from N10°E to N20°E. Drainage area from production analyses was calculated to be 48.7 acres in northwest Parker County. Natural fractures were encountered in the Davis, causing severe drilling problems in Data Well No. 1. Davis was therefore suspended.Bureau of Economic Geolog
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Analysis of Natural Fractures and Borehole Ellipticity Travis Peak Formation East Texas
This report summarizes petrographic studies of natural and coring-induced fractures in 7 cores from the Travis Peak Formation, a low-permeability gas sandstone in East Texas, and also presents an analysis of fracturing and wellbore elongation based on Borehole Televiewer, Formation Microscanner, and Ellipticity logs from 12 Travis Peak wells.
Natural, vertical extension fractures in sandstone are open or only partly mineral-filled in the cored depth range (approximately -5,000 to -10,000 ft), and they are therefore potential gas reservoirs as well as a potentially important influence on commercial hydraulic fracture treatment. Crack-seal structure in fracture-filling quartz shows that fracturing and quartz cementation were contemporary; this result, together with evidence of timing of fracturing and the large water volumes that are inferred to have passed through the Travis Peak, suggests that natural hydraulic fracturing influenced fracture development.
Healed transgranular microfractures that occur in sandstone can be used to ascertain natural fracture trends in core that lacks macrofractures, and coring-induced petal-centerline fractures can be used to infer stress orientations. Fractures trend ENE to E. In the upper Travis Peak, borehole ellipticity trends ENE, parallel to fracture trends, and in the lower Travis Peak ellipticity trends NNW, parallel to the direction of least horizontal stress.Bureau of Economic Geolog
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Site Selection for Gri Cooperative Tight Gas Field Resesarch Volume 2: Geologic Characteristics of Selected Low-Permeability Gas Sandstones
Geological, engineering, and economic data on selected formations were compiled to provide a basis for siting the fourth Staged Field Experiment (SFE) for the Tight Gas Sands research program. The geologic units chosen are the Abo, Cleveland, and Frontier Formations, and the Mesaverde Group. Extrapolation potential is good for all formations except the Cleveland, whose thin deltaic package has no good analogy in other low-permeability sandstones. The Abo has the best potential for extrapolation to other low-permeability formations. The average thickness of reservoirs is about 250 ft in the Mesaverde and Abo, 160 ft in the Frontier, and 120 ft in the Cleveland. The deepest production depth varies from 4,750 ft (Abo) to 12,198 ft (Second Frontier sandstone). The estimated resource base ranges from 3 TCF (Abo) to 86 TCF (Mesaverde). Pre-stimulation production ranges from too small to measure (Cleveland, Frontier, Mesaverde) to 314 MCFD (Frontier). Post-stimulation production ranges from 3 MCFD (Mesaverde) to 12,250 MCFD (Cleveland). Permeability ranges from less than 0.0001 md (Frontier) to 1.3 md (Frontier). Natural fractures have been shown to be significant locally in the Mesaverde, but their contribution to reservoir permeability in the other formations is not well-documented.Bureau of Economic Geolog