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Growth of a tectonic ridge

Description: The 28 June 1992 Landers, California, earthquake of M 7.6 created an impressive record of surface rupture and ground deformation. Fractures extend over a length of more than 80 km including zones of right-lateral shift, steps in the fault zones, fault intersections and vertical changes. Among the vertical changes was the growth of a tectonic ridge described here. In this paper the authors describe the Emerson fault zone and the Tortoise Hill ridge including the relations between the fault zone … more
Date: December 31, 1997
Creator: Fleming, Robert W.; Messerich, James A. & Johnson, Arvid M.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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[Mechano-chemical self-organization and nonlinear dynamics in sedimentary basins]

Description: The central theme of this project is that the reaction, transport and mechanical (RTM) processes affect each other so strongly that basin diagenesis takes on a qualitatively different behavior than what would be predicted by the analysis of the individual processes separately. In Figs. 1 and 2 we see schematic basin cross-sections that emphasize a few of the diagenetic phenomena arising from the strong coupling of RTM processes. Basin diagenesis allows for a great richness of phenomena (Fig. 1)… more
Date: January 1, 1993
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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NATURE OF THE DRY SHADOW BELOW CAVITIES IN VADOSE ZONE

Description: Several theoretical studies have indicated that the presence of subsurface cavities in the vadose zone results in complete or partial diversion of flow around cavities. As a result, the region immediately below the cavities is partially shielded from the downward flux. This shadowing effect of cavities can be exploited in the design of dry subsurface storage facilities as an additional barrier to contain waste within or around the cavities. However, empirical evidence that supports these theori… more
Date: September 7, 2005
Creator: Ghezzehei, Teamrat A.; Kneafsey, Timothy J. & Su, Grace W.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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Discrete fracture simulations of the hydrogeology at Koongarra, Northern Territory, Australia

Description: The US Department of Energy is studying the Alligator Rivers Natural Analogue Project site at Koongarra, Northern Territory, Australia to investigate and simulate radionuclide migration in fractured rocks. Discrete fracture simulations were conducted within a cubic volume (180-m edge length) of fractured Cahill Formation schist oriented with one major axis parallel to the trend of the Koongarra Fault. Five hundred fractures are simulated within this domain. The fractures have a mean orientation… more
Date: April 1, 1992
Creator: Smoot, J. L.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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On Two-Phase Relative Permeability and Capillary Pressure ofRough-Walled Rock Fractures

Description: 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 nonwetting phase, respectively, according to local capillary pressure and accessibility criteria. Phase occupancy and permeability are derived by assuming a parallel-pl… more
Date: September 1989
Creator: Pruess, K. & Tsang, Y. W.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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Final Report - Advanced Conceptual Models for Unsaturated and Two-Phase Flow in Fractured Rock

Description: The Department of Energy Environmental Management Program is faced with two major issues involving two-phase flow in fractured rock; specifically, transport of dissolved contaminants in the Vadose Zone, and the fate of Dense Nonaqueous Phase Liquids (DNAPLs) below the water table. Conceptual models currently used to address these problems do not correctly include the influence of the fractures, thus leading to erroneous predictions. Recent work has shown that it is crucial to understand the top… more
Date: July 10, 2006
Creator: Nicholl, Michael J.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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CHARACTERIZATION OF IN-SITU STRESS AND PERMEABILITY IN FRACTURED RESERVOIRS

Description: During the past six months we have adapted our 3-D elastic, anisotropic finite difference code by implementing the rotated staggered grid (RSG) method to more accurately represent large contrasts of elastic moduli between the fractures and surrounding formation, and applying the perfectly matched layer (PML) absorbing boundary condition to minimize boundary reflections. Two approaches for estimating fracture spacing from scattered seismic energy were developed. The first relates notches in the … more
Date: August 1, 2005
Creator: Burns, Daniel R. & Toksoz, M. Nafi
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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Investigation of Efficiency Improvements During CO2 Injection in Hydraulically and Naturally Fractured Reservoirs Progress Report

Description: 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
Date: April 27, 2005
Creator: Schechter, David S.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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MULTI-PHASE FRACTURE-MATRIX INTERACTIONS UNDER STRESS CHANGES

Description: The main objectives of this project are to quantify the changes in fracture porosity and multiphase transport properties as a function of confining stress. These changes will be integrated into conceptual and numerical models that will improve our ability to predict and optimize fluid transport in fractured system. This report details our progress on: (a) developing the direct experimental measurements of fracture aperture and topology and fluid occupancy using high-resolution x-ray micro-tomog… more
Date: June 15, 2005
Creator: Grader, A.S.; Elsworth, D.; Halleck, P.M.; Alvarado, F.; Alajmi, A.; Karpyn, Z. et al.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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ADVANCED CHARACTERIZATION OF FRACTURED RESERVOIRS IN CARBONATE ROCKS: THE MICHIGAN BASIN

Description: Progress in year 2 of this project is highlighted by the completing of the writing and testing of the project database, ''Atlas'', and populating it with all the project data gathered to date. This includes digitization of 17,000+ original Scout Tickets for the Michigan Basin. Work continues on the Driller's Reports, where they have scanned about 50,000 pages out of an estimated 300,000 pages. All of the scanned images have been attached to ''Atlas'', the visual database viewer developed for th… more
Date: April 1, 2000
Creator: Wood, James R. & Harrison, William B.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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Characterizing fractured rock for fluid-flow, geomechanical, and paleostress modeling: Methods and preliminary results from Yucca Mountain, Nevada

Description: Fractures have been characterized for fluid-flow, geomechanical, and paleostress modeling at three localities in the vicinity of drill hole USW G-4 at Yucca Mountain in southwestern Nevada. A method for fracture characterization is introduced that integrates mapping fracture-trace networks and quantifying eight fracture parameters: trace length, orientation, connectivity, aperture, roughness, shear offset, trace-length density, and mineralization. A complex network of fractures was exposed on t… more
Date: December 31, 1993
Creator: Barton, C.C.; Larsen, E.; Page, W.R. & Howard, T.M.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
open access

CHARACTERIZATION OF IN-SITU STRESS AND PERMEABILITY IN FRACTURED RESERVOIRS

Description: Using a 3-D finite difference method with a rotated-staggered-grid (RSG) scheme we generated synthetic seismograms for a reservoir model consisting of three horizontal layers with the middle layer containing parallel, equally spaced fractures. By separating and analyzing the backscattered signals in the FK domain, we can obtain an estimate of the fracture spacing. The fracture spacing is estimated by taking one-half of the reciprocal of the dominant wavenumber of the backscattered energy in dat… more
Date: March 16, 2006
Creator: Burns, Daniel R. & Toksoz, Nafi
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
open access

Water infiltration and intermittent flow in rough-walled fractures

Description: 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 me… more
Date: May 1, 1995
Creator: Su, G.
Item Type: Refine your search to only Thesis or Dissertation
Partner: UNT Libraries Government Documents Department
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Geology of the Molina Member of the Wasatch Formation, Piceance Basin, Colorado

Description: The Molina Member of the Wasatch Formation has been cored in order to assess the presence/absence and character of microbial communities in the deep subsurface. Geological study of the Molina Member was undertaken in support of the microbiological tasks of this project, for the purposes of characterizing the host strata and of assessing the potential for post-depositional introduction of microbes into the strata. The Molina Member comprises a sandy fluvial unit within a formation dominated by m… more
Date: June 1, 1996
Creator: Lorenz, J.; Nadon, G. & LaFreniere, L.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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A new Eulerian-Lagrangian finite element simulator for solute transport in discrete fracture-matrix systems

Description: Fracture network simulators have extensively been used in the past for obtaining a better understanding of flow and transport processes in fractured rock. However, most of these models do not account for fluid or solute exchange between the fractures and the porous matrix, although diffusion into the matrix pores can have a major impact on the spreading of contaminants. In the present paper a new finite element code TRIPOLY is introduced which combines a powerful fracture network simulator with… more
Date: July 1, 1996
Creator: Birkholzer, J. & Karasaki, K.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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Estimation of hydrologic properties of an unsaturated, fractured rock mass

Description: In this document, two distinctly different approaches are used to develop continuum models to evaluate water movement in a fractured rock mass. Both models provide methods for estimating rock-mass hydrologic properties. Comparisons made over a range of different tuff properties show good qualitative and quantitative agreement between estimates of rock-mass hydrologic properties made by the two models. This document presents a general discussion of: (1) the hydrology of Yucca Mountain, and the c… more
Date: July 1, 1986
Creator: Klavetter, E. A. & Peters, R. R.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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Preliminary three-dimensional discrete fracture model, Tiva Canyon tuff, Yucca Mountain area, Nye County, Nevada

Description: A three-dimensional discrete fracture model was completed to investigate the potential effects of fractures on the flow of water at Yucca Mountain, Nye County, Nevada. A fracture network of the Exploratory Studies Facility starter tunnel area was simulated and calibrated with field data. Two modeled volumes were used to simulate three-dimensional fracture networks of the Tiva Canyon tuff. One volume had a width and length of 150 meters, and the other had a width and length of 200 meters; both v… more
Date: September 1, 1998
Creator: Anna, L. O.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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Naturally fractured tight gas reservoir detection optimization. Final report

Description: This DOE-funded research into seismic detection of natural fractures is one of six projects within the DOE`s Detection and Analysis of Naturally Fractured Gas Reservoirs Program, a multidisciplinary research initiative to develop technology for prediction, detection, and mapping of naturally fractured gas reservoirs. The demonstration of successful seismic techniques to locate subsurface zones of high fracture density and to guide drilling orientation for enhanced fracture permeability will ena… more
Date: November 19, 1997
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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Energy Partitioning of Seismic Waves in Fractured Rocks

Description: Advances in locating and characterizes fractures in oil and gas reservoirs, and at waste isolation sites from seismic surveys requires improved interpretation methods. Experimental and theoretical results from this work have lead to an understanding of diagnostic signatures of energy that is partitioned into body waves and guided modes by fractures. Compressional waves and shear waves (i.e., shear waves with particle motion perpendicular to the fracture plane) are sensitive to changes in shear … more
Date: August 31, 1997
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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Economic recovery of oil trapped at fan margins using high angle wells and multiple hydraulic fractures. [Quarterly report], October 1--December 31, 1995

Description: Objective is to use advanced technologies to demonstrate economic recovery of oil from the fan-margin portion of a slope-basin clastic reservoir. A high-angle well will be drilled in the fan margin and will be completed with multiple hydraulic-fracture treatments. Connectivity of thin reservoir layers will be established along the well path by the fracture planes. Geologic modeling, reservoir characterization, and fine-grid reservoir simulation will be used to select well location and orientati… more
Date: January 30, 1996
Creator: Niemeyer, B.L.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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Simulation of a field scale tritium tracer experiment in a fractured, weathered shale using discrete-fracture/matrix-diffusion and equivalent porous medium models

Description: Simulations of a tritium tracer experiment in fractured shale saprolite, conducted at the Oak Ridge National Laboratory, were performed using 1D and 2D equivalent porous medium (EPM) and discrete-fracture/matrix-diffusion (DFMD) models. The models successfully reproduced the general shape of the breakthrough curves in down-gradient monitoring wells which are characterized by rapid first arrival, a slow-moving center of mass, and a persistent ``tail`` of low concentration. In plan view, the plum… more
Date: May 1, 1996
Creator: Stafford, Paige L.
Item Type: Refine your search to only Thesis or Dissertation
Partner: UNT Libraries Government Documents Department
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Experimental and Theoretical Investigation of Multiphase Flow in Fractured Porous media, SUPRI TR-116, Topical Report

Description: The fluid transfer parameters between rock matrix and fracture are not well known. Consequently, simulation of fractured reservoirs uses, in general, very crude and unproven hypotheses such as zero capillary pressure in the fracture and/or relative permeability linear with saturation. In order to improve the understanding of flow in fractured media, an experimental study was conducted and numerical simulations of the experiments were made. A laboratory flow apparatus was built to obtain data on… more
Date: August 9, 1999
Creator: Akin, Serhat; Castanier, Louis M. & German, Edgar Rene Rangel
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
open access

A simple procedure for estimating the effective hydraulic conductivity of a two-dimensional saturated or partly-saturated fracture network

Description: Many of the sites that have been proposed as potential locations of underground radioactive waste respositories contain fractured rocks. When modeling the hydrological behavior of these sites, for either the purpose of site characterization or performance assessment, computational gridblocks are often used that contain large numbers of individual fractures. In order to treat these gridblocks as equivalent continua, it is necessary to develop a procedure for relating the hydraulic properties of … more
Date: April 1, 1995
Creator: Zimmerman, R. W. & Bodvarsson, G. S.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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