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Reply to comments by Veling on"A Semi-Analytical Solution for Large-Scale Injection-Induced Pressure Perturbation and Leakage in a Laterally Bounded Aquifer-Aquitard System"

Description: Veling (2010) pointed to 'a serious mistake' and 'mathematical inconsistency' in Zhou et al. (2009) because the dimensionless flow equations in Equation 4 (in terms of dimensionless hydraulic head rise in the aquifer and the aquitard) would give rise to additional terms when back converting to the groundwater flow equations, in the case that initial conditions for hydraulic head were spatially variable. He added, however, that the conclusions of the paper remain valid when uniform initial condi… more
Date: May 1, 2011
Creator: Zhou, Q.; Birkholzer, J. T. & Tsang, C.-F.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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Analytical solution for Joule-Thomson cooling during CO2 geo-sequestration in depleted oil and gas reservoirs

Description: Mathematical tools are needed to screen out sites where Joule-Thomson cooling is a prohibitive factor for CO{sub 2} geo-sequestration and to design approaches to mitigate the effect. In this paper, a simple analytical solution is developed by invoking steady-state flow and constant thermophysical properties. The analytical solution allows fast evaluation of spatiotemporal temperature fields, resulting from constant-rate CO{sub 2} injection. The applicability of the analytical solution is demons… more
Date: May 21, 2010
Creator: Mathias, S.A.; Gluyas, J.G.; Oldenburg, C.M. & Tsang, C.-F.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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Estimation of deformation and stiffness of fractures close to tunnels using data from single-hole hydraulic testing and grouting

Description: Sealing of tunnels in fractured rocks is commonly performed by pre- or post-excavation grouting. The grouting boreholes are frequently drilled close to the tunnel wall, an area where rock stresses can be low and fractures can more easily open up during grout pressurization. In this paper we suggest that data from hydraulic testing and grouting can be used to identify grout-induced fracture opening, to estimate fracture stiffness of such fractures, and to evaluate its impact on the grout perform… more
Date: May 1, 2010
Creator: Fransson, A.; Tsang, C.-F.; Rutqvist, J. & Gustafson, G.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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Insight from simulations of single-well injection-withdrawal tracer tests on simple and complex fractures

Description: The single-well injection withdrawal (SWIW) test, a tracer test utilizing only one well, is proposed as a useful contribution to site characterization of fractured rock, as well as providing parameters relevant to tracer diffusion and sorption. The usual conceptual model of flow and solute transport through fractured rock with low matrix permeability involves solute advection and dispersion through a fracture network coupled with diffusion and sorption into the surrounding rock matrix. Unlike t… more
Date: August 6, 2009
Creator: Tsang, C.-F. & Doughty, C.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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Analysis of three sets of SWIW tracer-test data using a two-population complex fracture model for matrix diffusion and sorption

Description: A complex fracture model employing two populations for diffusion and sorption is proposed to analyze three representative single-well injection-withdrawal (SWIW) tracer tests from Forsmark and Laxemar, the two sites under investigation by the Swedish Nuclear Fuel and Waste Management Company (SKB). One population represents the semi-infinite rock matrix and the other represents finite blocks that can become saturated, thereafter accepting no further diffusion or sorption. The diffusion and sorp… more
Date: August 1, 2009
Creator: Doughty, C. & Tsang, C. F.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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Large-scale impact of CO2 storage in deep saline aquifers: A sensitivity study on pressure response in stratified systems

Description: Large volumes of CO{sub 2} captured from carbon emitters (such as coal-fired power plants) may be stored in deep saline aquifers as a means of mitigating climate change. Storing these additional fluids may cause pressure changes and displacement of native brines, affecting subsurface volumes that can be significantly larger than the CO{sub 2} plume itself. This study aimed at determining the three-dimensional region of influence during/after injection of CO{sub 2} and evaluating the possible im… more
Date: November 1, 2008
Creator: Birkholzer, J.T.; Zhou, Q. & Tsang, C.-F.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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Mesoscale Characterization of Coupled Hydromechanical Behavior of a Fractured Porous Slope in Response to Free Water-Surface Movement

Description: To better understand the role of groundwater-level changes on rock-slope deformation and damage, a carbonate rock slope (30 m x 30 m x 15 m) was extensively instrumented for mesoscale hydraulic and mechanical measurements during water-level changes. The slope is naturally drained by a spring that can be artificially closed or opened by a water gate. In this study, a 2-hour slope-dewatering experiment was analyzed. Changes in fluid pressure and deformation were simultaneously monitored, both at … more
Date: May 15, 2008
Creator: Rutqvist, Jonny; Guglielmi, Y.; Cappa, F.; Rutqvist, J.; Tsang, C.-F. & Thoraval, A.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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A Comparative Review of Hydrologic Issues Involved in Geologic Storage of CO2 and Injection Disposal of Liquid Waste

Description: The paper presents a comparison of hydrologic issues and technical approaches used in deep-well injection and disposal of liquid wastes, and those issues and approaches associated with injection and storage of CO{sub 2} in deep brine formations. These comparisons have been discussed in nine areas: (1) Injection well integrity; (2) Abandoned well problems; (3) Buoyancy effects; (4) Multiphase flow effects; (5) Heterogeneity and flow channeling; (6) Multilayer isolation effects; (7) Caprock effec… more
Date: April 15, 2008
Creator: Tsang, C.-F.; Birkholzer, J. & Rutqvist, J.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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Estimation of fracture flow parameters through numerical analysis of hydromechanical pressure pulses

Description: 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 significa… more
Date: March 16, 2008
Creator: Cappa, F.; Guglielmi, Y.; Rutqvist, J.; Tsang, C.-F. & Thoraval, A.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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A method for quick assessment of CO2 storage capacity in closed and semi-closed saline formations

Description: Saline aquifers of high permeability bounded by overlying/underlying seals may be surrounded laterally by low-permeability zones, possibly caused by natural heterogeneity and/or faulting. Carbon dioxide (CO{sub 2}) injection into and storage in such 'closed' systems with impervious seals, or 'semi-closed' systems with nonideal (low-permeability) seals, is different from that in 'open' systems, from which the displaced brine can easily escape laterally. In closed or semi-closed systems, the pres… more
Date: February 10, 2008
Creator: Zhou, Q.; Birkholzer, J.; Tsang, C. F. & Rutqvist, J.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
open access

A New Parameter to Assess Hydromechanical Effect in Single-hole Hydraulic Testing and Grouting

Description: Grouting or filling of the open voids in fractured rock is done by introducing a fluid, a grout, through boreholes under pressure. The grout may be either a Newtonian fluid or a Bingham fluid. The penetration of the grout and the resulting pressure profile may give rise to hydromechanical effects, which depends on factors such as the fracture aperture, pressure at the borehole and the rheological properties of the grout. In this paper, we postulate that a new parameter, {angstrom}, which is the… more
Date: September 1, 2007
Creator: Rutqvist, Jonny; Fransson, A.; Tsang, C.-F.; Rutqvist, J. & Gustafson, G.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
open access

Application of direct-fitting, mass-integral, and multi-ratemethods to analysis of flowing fluid electric conductivity logs fromHoronobe, Japan

Description: The flowing fluid electric conductivity (FFEC) loggingmethod is an efficient way to provide information on the depths,salinities, and transmissivities of individual conductive featuresintercepted by a borehole, without the use of specialized probes. Usingit in a multiple-flow-rate mode allows, in addition, an estimate of theinherent "far-field" pressure heads in each of the conductive features.The multi-rate method was successfully applied to a 500-m borehole in agranitic formation and reported… more
Date: August 1, 2007
Creator: Doughty, C.; Tsang, C.-F.; Hatanaka, K.; Yabuuchi, S. & Kurikami, H.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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Coupled Reservoir-Geomechanical Analysis of the Potential for Tensile and Shear Failure Associated With CO2 Injection in Multilayered Reservoir-Caprock Systems

Description: Coupled reservoir-geomechanical simulations were conductedto study the potential for tensile and shear failure e.g., tensilefracturing and shear slip along pre-existing fractures associated withunderground CO2 injection in a multilayered geological system. Thisfailure analysis aimed to study factors affecting the potential forbreaching a geological CO2 storage system and to study methods forestimating the maximum CO2 injection pressure that could be sustainedwithout causing such a breach. We pa… more
Date: March 27, 2007
Creator: Rutqvist, J.; Birkholzer, J. T. & Tsang, C.-F.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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Sensitivity study of CO2 storage capacity in brine aquifers withclosed boundaries: Dependence on hydrogeologic properties

Description: In large-scale geologic storage projects, the injected volumes of CO{sub 2} will displace huge volumes of native brine. If the designated storage formation is a closed system, e.g., a geologic unit that is compartmentalized by (almost) impermeable sealing units and/or sealing faults, the native brine cannot (easily) escape from the target reservoir. Thus the amount of supercritical CO{sub 2} that can be stored in such a system depends ultimately on how much pore space can be made available for … more
Date: February 7, 2007
Creator: Zhou, Q.; Birkholzer, J.; Rutqvist, J. & Tsang, C-F.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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Estimating maximum sustainable injection pressure duringgeological sequestration of CO2 using coupled fluid flow andgeomechanical fault-slip analysis

Description: This paper demonstrates the use of coupled fluid flow andgeomechanical fault slip (fault reactivation) analysis to estimate themaximum sustainable injection pressure during geological sequestration ofCO2. Two numerical modeling approaches for analyzing faultslip areapplied, one using continuum stress-strain analysis and the other usingdiscrete fault analysis. The results of these two approaches to numericalfault-slip analyses are compared to the results of a more conventionalanalytical fault-sl… more
Date: October 17, 2006
Creator: Rutqvist, J.; Birkholzer, J.; Cappa, F. & Tsang, C.-F.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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Hydromechanical modeling of pulse tests that measure both fluidpressure and fracture-normal displacement of the Coaraze Laboratory site,France

Description: In situ fracture mechanical deformation and fluid flowinteractions are investigated through a series of hydraulic pulseinjection tests, using specialized borehole equipment that cansimultaneously measure fluid pressure and fracture displacements. Thetests were conducted in two horizontal boreholes spaced one meter apartvertically and intersecting a near-vertical highly permeable faultlocated within a shallow fractured carbonate rock. The field data wereevaluated by conducting a series of couple… more
Date: April 22, 2006
Creator: Cappa, F.; Guglielmi, Y.; Rutqvist, J.; Tsang, C-F. & Thoraval, A.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
open access

Large Releases from CO2 Storage Reservoirs: A Discussion ofNatural Analogs, FEPS, and Modeling Needs

Description: While the purpose of geologic storage in deep saline formations is to trap greenhouse gases underground, the potential exists for CO{sub 2} to escape from the target reservoir, migrate upward along permeable pathways, and discharge at the land surface. In this paper, we evaluate the potential for such CO{sub 2} discharges based on the analysis of natural analogs, where large releases of gas have been observed. We are particularly interested in circumstances that could generate sudden, possibly … more
Date: November 1, 2005
Creator: Birkholzer, J.; Pruess, K.; Lewicki, J. L.; Rutqvist, J.; Tsang, C-F. & Karimjee, A.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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Analysis of Coupled Multiphase Fluid Flow, Heat Transfer and Mechanical Deformation at the Yucca Mountain Drift Scale Test

Description: A numerical simulation of coupled multiphase fluid flow, heat transfer, and mechanical deformation was carried out to study coupled thermal-hydrological-mechanical (THM) processes at the Yucca Mountain Drift Scale Test (DST) and for validation of a coupled THM numerical simulator. The ability of the numerical simulator to model relevant coupled THM processes at the DST was evaluated by comparison of numerical results to in situ measurements of temperature, water saturation, displacement, and fr… more
Date: May 17, 2005
Creator: Rutqvist, J.; Tsang, C. F. & Tsang, Y.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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Numerical study of the THM effects on the near-field safety of ahypothetical nuclear waste repository - BMT1 of the DECOVALEX IIIproject. Part 3: Effects of THM coupling in sparsely fracturedrocks

Description: BENCHPAR project, the impact of thermal-hydrological-mechanical (THM) couplings on the performance of a bentonite-back-filled nuclear waste repository in near-field crystalline rocks is evaluated in a Bench-Mark Test problem (BMT1) and the results are presented in a series of three companion papers in this issue. This is the third paper with focus on the effects of THM processes at a repository located in a sparsely fractured rock. Several independent coupled THM analyses presented in this pape… more
Date: September 9, 2004
Creator: Rutqvist, J.; Chijimatsu, M.; Jing, L.; Millard, A.; Nguyen,T. S.; Rejeb, A. et al.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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Coupled thermal-hydrological-mechanical analyses of the YuccaMountain Drift Scale Test - Comparison of field measurements topredictions of four different numerical models

Description: The Yucca Mountain Drift Scale Test (DST) is a multiyear, large-scale underground heater test designed to study coupled thermal-hydrological-mechanical-chemical behavior in unsaturated fractured and welded tuff. As part of the international cooperative code-comparison project DECOVALEX, four research teams used four different numerical models to simulate and predict coupled thermal-hydrological-mechanical (THM) processes at the DST. The simulated processes included above-boiling temperature cha… more
Date: August 30, 2004
Creator: Rutqvist, J.; Barr, D.; Datta, R.; Gens, A.; Millard, A.; Olivella, S. et al.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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Analyses of coupled hydrological-mechanical effects during drilling of the FEBEX tunnel at Grimsel

Description: This paper presents analyses of coupled hydrological-mechanical (HM) processes during drilling of the FEBEX tunnel, located in fractured granite at Grimsel, Switzerland. Two and three-dimensional transient finite-element simulations were performed to investigate HM-induced fluid-pressure pulses, observed in the vicinity of the FEBEX tunnel during its excavation in 1995. The results show that fluid-pressure responses observed in the rock mass during TBM drilling of the FEBEX tunnel could not be … more
Date: September 2, 2003
Creator: Rutqvist, J.; Rejeb, A.; Tijani, M. & Tsang, C.-F.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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A fully coupled three-dimensional THM analysis of the FEBEX in situ test with the ROCMAS Code: Prediction of THM behavior in a bentonite barrier

Description: This paper presents a fully coupled thermal-hydrological-mechanical analysis of FEBEX--a large underground heater test conducted in a bentonite and fractured rock system. System responses predicted by the numerical analysis--including temperature, moisture content, and bentonite-swelling stress--were compared to field measurements at sensors located in the bentonite. An overall good agreement between predicted and measured system responses shows that coupled thermal-hydrological-mechanical proc… more
Date: September 1, 2003
Creator: Rutqvist, J. & Tsang, C-F.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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