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Advanced Vadose Zone Simulations Using TOUGH

Description: The vadose zone can be characterized as a complex subsurfacesystem in which intricate physical and biogeochemical processes occur inresponse to a variety of natural forcings and human activities. Thismakes it difficult to describe, understand, and predict the behavior ofthis specific subsurface system. The TOUGH nonisothermal multiphase flowsimulators are well-suited to perform advanced vadose zone studies. Theconceptual models underlying the TOUGH simulators are capable ofrepresenting features… more
Date: February 1, 2007
Creator: Finsterle, S.; Doughty, C.; Kowalsky, M.B.; Moridis, G.J.; Pan,L.; Xu, T. et al.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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Inverse modeling and forecasting for the exploitation of the Pauzhetsky geothermal field, Kamchatka, Russia

Description: A three-dimensional numerical model of the Pauzhetsky geothermal field has been developed based on a conceptual hydrogeological model of the system. It extends over a 13.6-km2 area and includes three layers: (1) a base layer with inflow; (2) a geothermal reservoir; and (3) an upper layer with discharge and recharge/infiltration areas. Using the computer program iTOUGH2 (Finsterle, 2004), the model is calibrated to a total of 13,675 calibration points, combining natural-state and 1960-2006 explo… more
Date: April 1, 2008
Creator: Finsterle, Stefan; Kiryukhin, A.V.; Asaulova, N.P. & Finsterle, S.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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Mass- and temperature-dependent diffusion coefficients for lightnoble gases for the TOUGH2-EOSN Model

Description: This report describes modifications made to the EOSN module(Shan and Pruess, 2003) of the nonisothermal multiphase flow simulatorTOUGH2 (Pruess, et al., 1999). The EOSN fluid property module simulatestransport of water, brine, air, and noble gases or CO2 in the subsurface.In the standard version of the EOSN module, diffusion coefficients can bespecified by the user, but there is no allowance for liquid-phasediffusion coefficients to change with temperature. Furthermore, usersmust specify radiog… more
Date: April 13, 2007
Creator: Andrews, J. L.; Finsterle, S. & Saar, M. O.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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Electrokinetic coupling in unsaturated porous media

Description: We consider a charged porous material that is saturated bytwo fluid phases that are immiscible and continuous on the scale of arepresentative elementary volume. The wetting phase for the grains iswater and the nonwetting phase is assumed to be an electricallyinsulating viscous fluid. We use a volume-averaging approach to derivethe linear constitutive equations for the electrical current density aswell as the seepage velocities of the wetting and nonwetting phases onthe scale of a representative… more
Date: February 27, 2007
Creator: Revil, A.; Linde, N.; Cerepi, A.; Jougnot, D.; Matthai, S. & Finsterle, S.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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Sensitivity analysis for joint inversion of ground-penetratingradar and thermal-hydrological data from a large-scale underground heatertest

Description: We describe a joint inversion approach that combinesgeophysical and thermal-hydrological data for the estimation of (1)thermal-hydrological parameters (such as permeability, porosity, thermalconductivity, and parameters of the capillary pressure and relativepermeability functions) that are necessary for predicting the flow offluids and heat in fractured porous media, and (2) parameters of thepetrophysical function that relates water saturation, porosity andtemperature to the dielectric constant… more
Date: June 25, 2007
Creator: Kowalsky, M. B.; Birkholzer, J.; Peterson, J.; Finsterle, S.; Mukhopadhya, Y. S. & Tsang, Y. T.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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Inverse modeling of test SB4-VM2/216.7 at Wellenberg

Description: Pressure and flow rate data from a water sampling test, which also produced gas, at the Wellenberg site are analyzed using inverse modeling techniques. Two conceptual models are developed and used for parameter estimation. The first model assumes that the gas observed at the surface is dissolved in the pore water under natural pressure and temperature conditions and comes out of solution due to the pressure reduction during pumping. The second model considers a mobile gas phase originally prese… more
Date: March 1, 1994
Creator: Finsterle, S.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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A TOUGH2 equation-of-state module for the simulation of two-phase flow of air, water, and a miscible gelling liquid

Description: The injection of grout into the subsurface can be used to encapsulate contaminated regions of an aquifer, or to form underground barriers for the isolation of contaminant sources and to prevent the spreading of existing plumes. This requires identifying grouts, or barrier fluids, which when injected into the subsurface exhibit a large increase in viscosity and eventually solidify, sealing the permeable zones in the aquifer. Simulation and modeling analysis are indispensable tools for designing … more
Date: May 1, 1994
Creator: Finsterle, S.; Moridis, G. J. & Pruess, K.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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A truncated Levenberg-Marquardt algorithm for the calibration of highly parameterized nonlinear models

Description: We propose a modification to the Levenberg-Marquardt minimization algorithm for a more robust and more efficient calibration of highly parameterized, strongly nonlinear models of multiphase flow through porous media. The new method combines the advantages of truncated singular value decomposition with those of the classical Levenberg-Marquardt algorithm, thus enabling a more robust solution of underdetermined inverse problems with complex relations between the parameters to be estimated and the… more
Date: October 15, 2010
Creator: Finsterle, S. & Kowalsky, M.B.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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Bentonite alteration due to thermal-hydro-chemical processes during the early thermal period in a nuclear waste repository

Description: After closure of an underground nuclear waste repository, the decay of radionuclides will raise temperature in the repository, and the bentonite buffer will resaturate by water inflow from the surrounding host rock. The perturbations from these thermal and hydrological processes are expected to dissipate within hundreds to a few thousand years. Here, we investigate coupled thermal-hydro-chemical processes and their effects on the short-term performance of a potential nuclear waste repository lo… more
Date: February 1, 2011
Creator: Xu, T.; Senger, R. & Finsterle, S.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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Factors governing sustainable groundwater pumping near a river

Description: The objective of this paper is to provide new insights into processes affecting riverbank filtration (RBF). We consider a system with an inflatable dam installed for enhancing water production from downstream collector wells. Using a numerical model, we investigate the impact of groundwater pumping and dam operation on the hydrodynamics in the aquifer and water production. We focus our study on two processes that potentially limit water production of an RBF system: the development of an unsatur… more
Date: January 15, 2011
Creator: Zhang, Y.; Hubbard, S. S. & Finsterle, S.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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An asixymmetric diffusion experiment for the determination of diffusion and sorption coefficients of rock samples

Description: Diffusion anisotropy is a critical property in predicting migration of substances in sedimentary formations with very low permeability. The diffusion anisotropy of sedimentary rocks has been evaluated mainly from laboratory diffusion experiments, in which the directional diffusivities are separately estimated by through-diffusion experiments using different rock samples, or concurrently by in-diffusion experiments in which only the tracer profile in a rock block is measured. To estimate the dif… more
Date: February 1, 2011
Creator: Takeda, M.; Hiratsuka, T.; Ito, K. & Finsterle, S.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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ITOUGH2 user`s guide version 2.2

Description: ITOUGH2 is a program to estimate hydrogeologic model parameters for the numerical simulator TOUGH2. TOUGH2 was developed by Karsten Pruess at Lawrence Berkeley Laboratory for simulating non-isothermal flows of multicomponent, multiphase fluids in porous and fractured media. ITOUGH2 solves the inverse problem by automatic model calibration based on an indirect approach, in which some function of the difference between observed and model-predicted system response and appropriately weighted prior … more
Date: August 1, 1993
Creator: Finsterle, S.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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Estimating two-phase hydraulic properties by inverse modeling

Description: Disposal of high-level nuclear waste in geologic formations requires characterizing the hydrogeologic conditions at the potential site. This involves extensive data interpretation from laboratory and field experiments which are being performed on different scales. Two-phase flow processes are relevant if the potential site is located in the unsaturated zone, but they are also studied for repositories beneath the water table if the waste packages generate significant amounts of free gas. Numeric… more
Date: January 1, 1994
Creator: Finsterle, S. & Pruess, K.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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Corrosion-induced gas generation in a nuclear waste repository: Reactive geochemistry and multiphase flow effect

Description: Corrosion of steel canisters, stored in a repository for spent fuel and high-level nuclear wastes, leads to the generation and accumulation of hydrogen gas in the backfilled emplacement tunnels, which may significantly affect long-term repository safety. Previous studies used H{sub 2} generation rates based on the volume of the waste or canister material and the stoichiometry of the corrosion reaction. However, iron corrosion and H{sub 2} generation rates vary with time, depending on factors su… more
Date: October 15, 2008
Creator: Xu, T.; Senger, R. & Finsterle, S.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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Ground surface temperature reconstructions: Using in situ estimates for thermal conductivity acquired with a fiber-optic distributed thermal perturbation sensor

Description: We have developed a borehole methodology to estimate formation thermal conductivity in situ with a spatial resolution of one meter. In parallel with a fiber-optic distributed temperature sensor (DTS), a resistance heater is deployed to create a controlled thermal perturbation. The transient thermal data is inverted to estimate the formation's thermal conductivity. We refer to this instrumentation as a Distributed Thermal Perturbation Sensor (DTPS), given the distributed nature of the DTS measur… more
Date: October 10, 2008
Creator: Freifeld, B. M.; Finsterle, S.; Onstott, T. C.; Toole, P. & Pratt, L. M.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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Parameter estimation from flowing fluid temperature logging data in unsaturated fractured rock using multiphase inverse modeling

Description: A simple conceptual model has been recently developed for analyzing pressure and temperature data from flowing fluid temperature logging (FFTL) in unsaturated fractured rock. Using this conceptual model, we developed an analytical solution for FFTL pressure response, and a semianalytical solution for FFTL temperature response. We also proposed a method for estimating fracture permeability from FFTL temperature data. The conceptual model was based on some simplifying assumptions, particularly th… more
Date: January 15, 2009
Creator: Mukhopadhyay, S.; Tsang, Y. & Finsterle, S.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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Percolation-theory and fuzzy rule-based probability estimation of fault leakage at geologic carbon sequestration sites

Description: Leakage of CO{sub 2} and displaced brine from geologic carbon sequestration (GCS) sites into potable groundwater or to the near-surface environment is a primary concern for safety and effectiveness of GCS. The focus of this study is on the estimation of the probability of CO{sub 2} leakage along conduits such as faults and fractures. This probability is controlled by (1) the probability that the CO{sub 2} plume encounters a conductive fault that could serve as a conduit for CO{sub 2} to leak th… more
Date: May 1, 2009
Creator: Zhang, Y.; Oldenburg, C.M. & Finsterle, S.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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Imaging Fluid Flow in Geothermal Wells Using Distributed Thermal Perturbation Sensing

Description: The objective of Task 2 is to develop a numerical method for the efficient and accurate analysis of distributed thermal perturbation sensing (DTPS) data for (1) imaging flow profiles and (2) in situ determination of thermal conductivities and heat fluxes. Numerical forward and inverse modeling is employed to: (1) Examine heat and fluid flow processes near a geothermal well under heating and cooling conditions; (2) Demonstrate ability to interpret DTPS thermal profiles with acceptable estimation… more
Date: December 10, 2010
Creator: Freifeld, B. & Finsterle, S.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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Testing and modeling of seepage into underground openings in aheterogeneous fracture system at Yucca Mountain, Nevada

Description: We discuss field activities designed to characterize seepage into an underground opening at the potential site for geologic storage of high-level radioactive waste (HLRW) at Yucca Mountain, Nevada, and the use of these data for development and calibration of a model for predicting seepage into planned HLRW emplacement drifts. Air-injection tests were conducted to characterize the permeability of the fractured rock, and liquid-release tests (LRTs) were conducted and seepage monitored to characte… more
Date: March 25, 2002
Creator: Ahlers, C. F.; Trautz, R. C.; Cook, P. J. & Finsterle, S.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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Evidence Of Rapid Localized Groundwater Transport In Volcanic Tuffs Beneath Yucca Mountain, Nevada

Description: At Yucca Mountain, Nevada-the proposed location for a national high-level nuclear waste repository-radionuclides, if released from breached waste storage canisters, could make their way down through the unsaturated zone (where the repository would be located) into the underlying groundwater and eventually back to the biosphere (i.e., where they could adversely affect human health). The compliance boundary, 18 km south of the proposed repository, is defined as the location where a human being us… more
Date: September 7, 2006
Creator: Freifeld, B.; Doughty, C.; Walker, J.; Kryder, L.; Gilmore, K.; Finsterle, S. et al.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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Automatic History Matching of Geothermal Field Performance

Description: We have developed inverse modeling capabilities for the multiphase multicomponent numerical simulator TOUGH2 to facilitate automatic history matching and parameter estimation based on data obtained during exploitation of geothermal fields. The ITOUGH2 code allows one to estimate TOUGH2 input parameters based on any type of observation for which a corresponding TOUGH2 output can be calculated. Furthermore, a detailed residual and error analysis is performed, and the uncertainty of model predicti… more
Date: January 1, 1995
Creator: Finsterle, S. & Pruess, K.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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COUPLING STATE-OF-THE-SCIENCE SUBSURFACE SIMULATION WITH ADVANCED USER INTERFACE AND PARALLEL VISUALIZATION: SBIR Phase I Final Report

Description: This is a Phase I report on a project to significantly enhance existing subsurface simulation software using leadership-class computing resources, allowing researchers to solve problems with greater speed and accuracy. Subsurface computer simulation is used for monitoring the behavior of contaminants around nuclear waste disposal and storage areas, groundwater flow, environmental remediation, carbon sequestration, methane hydrate production, and geothermal energy reservoir analysis. The Phase I… more
Date: April 30, 2008
Creator: Hardeman, B.; Swenson, D.; Finsterle, S. & Zhou, Q.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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Single-well experimental design for studying residual trapping of superciritcal carbon dioxide

Description: The objective of our research is to design a single-well injection-withdrawal test to evaluate residual phase trapping at potential CO{sub 2} geological storage sites. Given the significant depths targeted for CO{sub 2} storage and the resulting high costs associated with drilling to those depths, it is attractive to develop a single-well test that can provide data to assess reservoir properties and reduce uncertainties in the appraisal phase of site investigation. The main challenges in a sing… more
Date: June 15, 2010
Creator: Zhang, Y.; Freifeld, B.; Finsterle, S.; Leahy, M.; Ennis-King, J.; Paterson, L. et al.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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