The seismo-hydromechanical behavior during deep geothermal reservoir stimulations: open questions tackled in a decameter-scale in situ stimulation experiment

Abstract. In this contribution, we present a review of scientific research results that address seismo-hydromechanically coupled processes relevant for the development of a sustainable heat exchanger in low-permeability crystalline rock and introduce the design of the In situ Stimulation and Circulation (ISC) experiment at the Grimsel Test Site dedicated to studying such processes under controlled conditions. The review shows that research on reservoir stimulation for deep geothermal energy exploitation has been largely based on laboratory observations, large-scale projects and numerical models. Observations of full-scale reservoir stimulations have yielded important results. However, the limited access to the reservoir and limitations in the control on the experimental conditions during deep reservoir stimulations is insufficient to resolve the details of the hydromechanical processes that would enhance process understanding in a way that aids future stimulation design. Small-scale laboratory experiments provide fundamental insights into various processes relevant for enhanced geothermal energy, but suffer from (1) difficulties and uncertainties in upscaling the results to the field scale and (2) relatively homogeneous material and stress conditions that lead to an oversimplistic fracture flow and/or hydraulic fracture propagation behavior that is not representative of a heterogeneous reservoir. Thus, there is a need for intermediate-scale hydraulic stimulation experiments with high experimental control that bridge the various scales and for which access to the target rock mass with a comprehensive monitoring system is possible. The ISC experiment is designed to address open research questions in a naturally fractured and faulted crystalline rock mass at the Grimsel Test Site (Switzerland). Two hydraulic injection phases were executed to enhance the permeability of the rock mass. During the injection phases the rock mass deformation across fractures and within intact rock, the pore pressure distribution and propagation, and the microseismic response were monitored at a high spatial and temporal resolution.

[1]  L. Braile.  Seismic monitoring , 2019 .

[2]  D. Elsworth,et al.  Reservoir permeability mapping using microearthquake data , 2018 .

[3]  F. Amann,et al.  Stress Measurements in Crystalline Rock: Comparison of Overcoring, Hydraulic Fracturing and Induced Seismicity Results , 2018 .

[4]  D. Giardini,et al.  On the link between stress field and small-scale hydraulic fracture growth in anisotropic rock derived from microseismicity , 2017 .

[5]  G. Mariéthoz,et al.  A new global database to improve predictions of permeability distribution in crystalline rocks at site scale , 2017 .

[6]  T. Ishibashi,et al.  Frictional stability‐permeability relationships for fractures in shales , 2017 .

[7]  Grzegorz Kwiatek,et al.  Volumetric components in the earthquake source related to fluid injection and stress state , 2017 .

[8]  Julia Naomi Rosenfield Boeira.  Measuring and Analyzing , 2017 .

[9]  Robert G. Jeffrey,et al.  Hydraulic fracture growth in naturally fractured rock , 2017 .

[10]  David W. Eaton,et al.  Fault activation by hydraulic fracturing in western Canada , 2016, Science.

[11]  J. Douglas Zechar,et al.  Validating induced seismicity forecast models—Induced Seismicity Test Bench , 2016, 1609.02793.

[12]  Peter Bayer,et al.  Permeability Evolution in Natural Fractures Subject to Cyclic Loading and Gouge Formation , 2016, Rock Mechanics and Rock Engineering.

[13]  M. Saar,et al.  Multifluid geo-energy systems: Using geologic CO2 storage for geothermal energy production and grid-scale energy storage in sedimentary basins , 2016 .

[14]  F. Amann,et al.  Impact of the ISC Experiment at the Grimsel Test Site - Assessment of Potential Seismic Hazard and Disturbances to Nearby Experiments and KWO Infrastructure , 2016 .

[15]  Emmanuel M Detournay,et al.  Mechanics of Hydraulic Fractures , 2016 .

[16]  T. Ishibashi,et al.  Induced seismicity in the development of EGS—benefits and drawbacks , 2016 .

[17]  Leon Bieber.  The Mechanics Of Earthquakes And Faulting , 2016 .

[18]  M. Gutierrez,et al.  Fracture Dimension Investigation of Laboratory Hydraulic Fracture Interaction with Natural Discontinuity using Acoustic Emission , 2015 .

[19]  P. Dobson,et al.  Seismic and aseismic deformations and impact on reservoir permeability: The case of EGS stimulation at The Geysers, California, USA , 2015 .

[20]  Georg Houben,et al.  Review: Hydraulics of water wells—flow laws and influence of geometry , 2015, Hydrogeology Journal.

[21]  V. Gischig.  Rupture propagation behavior and the largest possible earthquake induced by fluid injection into deep reservoirs , 2015 .

[22]  Generation of large postinjection‐induced seismic events by backflow from dead‐end faults and fractures , 2015 .

[23]  M. Baan,et al.  Overview of moment-tensor inversion of microseismic events , 2015 .

[24]  Yves Guglielmi,et al.  Underground Research Laboratories for conducting fault activation experiments in shales , 2015 .

[25]  Tsuyoshi Ishida,et al.  Crack Extension in Hydraulic Fracturing of Shale Cores Using Viscous Oil, Water, and Liquid Carbon Dioxide , 2015, Rock Mechanics and Rock Engineering.

[26]  Pierre Henry,et al.  Seismicity triggered by fluid injection–induced aseismic slip , 2015, Science.

[27]  C. Cauzzi,et al.  Seismic monitoring and analysis of deep geothermal projects in St Gallen and Basel, Switzerland , 2015 .

[28]  M. Saar,et al.  Brine displacement by CO2, energy extraction rates, and lifespan of a CO2-limited CO2-Plume Geothermal (CPG) system with a horizontal production well , 2015 .

[29]  C. Scholz.  On the stress dependence of the earthquake b value , 2015 .

[30]  M. Saar,et al.  A comparison of electric power output of CO2 Plume Geothermal (CPG) and brine geothermal systems for varying reservoir conditions , 2015 .

[31]  S. Baisch,et al.  Continued Geothermal Reservoir Stimulation Experiments in the Cooper Basin (Australia) , 2015 .

[32]  Vanessa M. King,et al.  Induced seismicity constraints on subsurface geological structure, Paradox Valley, Colorado , 2015 .

[33]  S. Wiemer,et al.  Randomness of megathrust earthquakes implied by rapid stress recovery after the Japan earthquake , 2015 .

[34]  Valentin Gischig,et al.  Development of connected permeability in massive crystalline rocks through hydraulic fracture propagation and shearing accompanying fluid injection , 2015 .

[35]  V. Gischig,et al.  Hydro-Fracturing Versus Hydro-Shearing: A Critical Assessment of Two Distinct Reservoir Stimulation Mechanisms , 2015 .

[36]  Stefan Wiemer,et al.  Induced seismicity risk analysis of the 2006 Basel, Switzerland, Enhanced Geothermal System project: Influence of uncertainties on risk mitigation , 2015 .

[37]  Stefan Hirschberg,et al.  Energy from the earth: Deep geothermal as a resource for the future? , 2015 .

[38]  M. Ziegler,et al.  Characterisation of Natural Fractures and Fracture Zones of the Basel EGS Reservoir Inferred from Geophysical Logging of the Basel-1 Well , 2015 .

[39]  L. Eisner,et al.  Felt seismicity associated with shale gas hydraulic fracturing: The first documented example in Europe , 2014 .

[40]  Roland N. Horne,et al.  An investigation of stimulation mechanisms in Enhanced Geothermal Systems , 2014 .

[41]  Nicholas Deichmann,et al.  High-precision relocation and focal mechanism of the injection-induced seismicity at the Basel EGS , 2014 .

[42]  Nicholas Deichmann,et al.  Identification of faults activated during the stimulation of the Basel geothermal project from cluster analysis and focal mechanisms of the larger magnitude events , 2014 .

[43]  Jeoung Seok Yoon,et al.  Numerical investigation on optimized stimulation of intact and naturally fractured deep geothermal reservoirs using hydro-mechanical coupled discrete particles joints model , 2014 .

[44]  A. Alcolea,et al.  Balancing reservoir creation and seismic hazard in enhanced geothermal systems , 2014 .

[45]  P. Dobson,et al.  A 3D hydrogeological and geomechanical model of an Enhanced Geothermal System at The Geysers, California , 2014 .

[46]  Dimitrios Karvounis,et al.  Towards a Real-Time Forecast of Induced Seismicity for Enhanced Geothermal Systems , 2014 .

[47]  M. Saar,et al.  On the importance of the thermosiphon effect in CPG (CO2 plume geothermal) power systems , 2014 .

[48]  S. Wiemer,et al.  Systematic survey of high‐resolution b value imaging along Californian faults: Inference on asperities , 2014 .

[49]  Shawn Maxwell,et al.  Microseismic Imaging Of Hydraulic Fracturing : improved engineering of unconventional shale reservoirs , 2014 .

[50]  Derek Elsworth,et al.  Laboratory evidence for particle mobilization as a mechanism for permeability enhancement via dynamic stressing , 2013 .

[51]  Gioia Falcone,et al.  A systematic review of enhanced (or engineered) geothermal systems: past, present and future , 2013, Geothermal Energy.

[52]  Jeoung Seok Yoon,et al.  Fatigue hydraulic fracturing by cyclic reservoir treatment enhances permeability and reduces induced seismicity , 2013 .

[53]  Valentin Gischig,et al.  A stochastic model for induced seismicity based on non-linear pressure diffusion and irreversible permeability enhancement , 2013 .

[54]  R. Davies,et al.  Induced seismicity and hydraulic fracturing for the recovery of hydrocarbons , 2013 .

[55]  W. Ellsworth.  Injection-Induced Earthquakes , 2013, Science.

[56]  J. Rutqvist,et al.  Coupled seismo-hydromechanical monitoring of inelastic effects on injection-induced fracture permeability , 2013 .

[57]  G. Dresen,et al.  Stress Tensor Changes Related to Fluid Injection at The Geysers Geothermal Field, California , 2013 .

[58]  G. Abers,et al.  Potentially induced earthquakes in Oklahoma, USA: Links between wastewater injection and the 2011 Mw 5.7 earthquake sequence , 2013 .

[59]  Reinhard Jung.  EGS — Goodbye or Back to the Future 95 , 2013 .

[60]  Norman R. Warpinski,et al.  Understanding Hydraulic Fracture Growth, Effectiveness, and Safety Through Microseismic Monitoring , 2013 .

[61]  A. Bunger,et al.  Effective and Sustainable Hydraulic Fracturing , 2013 .

[62]  Stefan Wiemer,et al.  Generic dependence of the frequency‐size distribution of earthquakes on depth and its relation to the strength profile of the crust , 2013 .

[63]  P. Jeanne,et al.  Dissimilar properties within a carbonate-reservoir's small fault zone, and their impact on the pressurization and leakage associated with CO2 injection , 2013 .

[64]  S. Wiemer,et al.  The role of Coulomb stress changes for injection‐induced seismicity: The Basel enhanced geothermal system , 2013 .

[65]  A. McMahon,et al.  Flow Testing Results from Habanero EGS Project , 2013 .

[66]  C. Tsang,et al.  ISRM Suggested Method for Step-Rate Injection Method for Fracture In-Situ Properties (SIMFIP): Using a 3-Components Borehole Deformation Sensor , 2013, Rock Mechanics and Rock Engineering.

[67]  Susan Petty,et al.  Improving Geothermal Project Economics with Multi-zone Stimulation: Results from the Newberry Volcano EGS Demonstration , 2013 .

[68]  Reinhard Jung,et al.  EGS — Goodbye or Back to the Future , 2013 .

[69]  Stefan Wiemer,et al.  Geomechanical modeling of induced seismicity source parameters and implications for seismic hazard assessment , 2013 .

[70]  L. Germanovich,et al.  Nucleation and arrest of dynamic slip on a pressurized fault , 2012 .

[71]  F. Cornet.  The relationship between seismic and aseismic motions induced by forced fluid injections , 2012, Hydrogeology Journal.

[72]  Thomas Kohl,et al.  The role of triggering by static stress transfer during geothermal reservoir stimulation , 2012 .

[73]  D. Eaton,et al.  Comparing energy calculations: Hydraulic fracturing and microseismic monitoring , 2012 .

[74]  S. Wiemer,et al.  Influence of pore‐pressure on the event‐size distribution of induced earthquakes , 2012 .

[75]  D. Amitrano.  Variability in the power-law distributions of rupture events , 2012 .

[76]  Stefan Wiemer,et al.  Building Robust Models to Forecast the Induced Seismicity Related to Geothermal Reservoir Enhancement , 2012 .

[77]  Fabio Moia,et al.  A survey of the induced seismic responses to fluid injection in geothermal and CO2 reservoirs in Europe , 2012 .

[78]  Melinda Wright,et al.  OVERVIEW OF THE NORTHWEST GEYSERS EGS DEMONSTRATION PROJECT , 2012 .

[79]  E. Mohammadi,et al.  Barriers and facilitators related to the implementation of a physiological track and trigger system: A systematic review of the qualitative evidence , 2017, International journal for quality in health care : journal of the International Society for Quality in Health Care.

[80]  Mark W. McClure,et al.  The Importance of Slow Slip on Faults During Hydraulic Fracturing Stimulation of Shale Gas Reservoirs , 2012 .

[81]  Ivan G. Wong,et al.  Protocol for Addressing Induced Seismicity Associated with Enhanced Geothermal Systems , 2012 .

[82]  Martin O. Saar,et al.  Review: Geothermal heat as a tracer of large-scale groundwater flow and as a means to determine permeability fields , 2011 .

[83]  M. Zoback,et al.  Long Period, Long Duration Seismic Events During Hydraulic Fracture Stimulation of a Shale Gas Reservoir , 2011 .

[84]  G. Dresen,et al.  Source Parameters of Picoseismicity Recorded at Mponeng Deep Gold Mine, South Africa: Implications for Scaling Relations , 2011 .

[85]  Nicholas Deichmann,et al.  High fluid pressure and triggered earthquakes in the enhanced geothermal system in Basel, Switzerland , 2011 .

[86]  D. Schorlemmer,et al.  Identifying fault heterogeneity through mapping spatial anomalies in acoustic emission statistics , 2011 .

[87]  R. Horne,et al.  Investigation of injection-induced seismicity using a coupled fluid flow and rate/state friction model , 2011 .

[88]  Nicolas Cuenot,et al.  Large-scale aseismic motion identified through 4-D P-wave tomography , 2011 .

[89]  Stefan Wiemer,et al.  Statistical analysis of the induced Basel 2006 earthquake sequence: introducing a probability-based monitoring approach for Enhanced Geothermal Systems , 2011 .

[90]  C. Fairhurst,et al.  Fracture network engineering for hydraulic fracturing , 2011 .

[91]  Mark D. Zoback,et al.  Long-period, long-duration seismic events during hydraulic fracture stimulation of a shale gas reservoir , 2011 .

[92]  Jonny Rutqvist,et al.  Status of the TOUGH-FLAC simulator and recent applications related to coupled fluid flow and crustal deformations , 2011, Comput. Geosci..

[93]  Stefan Wiemer,et al.  Stress drop variations of induced earthquakes at the Basel geothermal site , 2011 .

[94]  M. Saar,et al.  Combining geothermal energy capture with geologic carbon dioxide sequestration , 2011 .

[95]  A. Bunger,et al.  Experimental Investigation of the Interaction Among Closely Spaced Hydraulic Fractures , 2011 .

[96]  N. Davatzes.  CRUSTAL STRESS HETEROGENEITY IN THE VICINITY OF COSO GEOTHERMAL FIELD , CA , 2011 .

[97]  Andrew P. Bunger,et al.  Parameters Effecting the Interaction among Closely Spaced Hydraulic Fractures , 2011 .

[98]  J. Vermylen,et al.  Hydraulic Fracturing, Microseismic Magnitudes, and Stress Evolution in the Barnett Shale, Texas, USA , 2011 .

[99]  Jimmy B. Randolph,et al.  Coupling carbon dioxide sequestration with geothermal energy capture in naturally permeable, porous geologic formations: Implications for CO2 sequestration , 2011 .

[100]  Zoe K. Shipton,et al.  A review of recent developments concerning the structure, mechanics and fluid flow properties of fault zones , 2010 .

[101]  Reinhard Jung,et al.  A numerical model for fluid injection induced seismicity at Soultz-sous-Forêts , 2010 .

[102]  Source mechanisms of micro-earthquakes induced in a fluid injection experiment at the HDR site Soultz-sous-Forêts (Alsace) in 2003 and their temporal and spatial variations , 2010 .

[103]  Arno Zang,et al.  Stress Field of the Earth's Crust , 2010 .

[104]  N. R. Warpinski,et al.  Source-Mechanism Studies on Microseismicity Induced by Hydraulic Fracturing , 2010 .

[105]  K. Evans,et al.  Stress Heterogeneity in the Granite of the Soultz EGS Reservoir Inferred from Analysis of Wellbore Failure , 2010 .

[106]  Albert Genter,et al.  Current Status of the EGS Soultz Geothermal Project (France) , 2010 .

[107]  Chunfang Meng,et al.  Hydraulic Fracture Propagation in Pre-Fractured Natural Rocks , 2010 .

[108]  C. Sondergeld,et al.  Microseismic Mapping of Laboratory Induced Hydraulic Fractures in Anisotropic Reservoirs , 2010, TGC 2010.

[109]  Subir K. Sanyal,et al.  FUTURE OF GEOTHERMAL ENERGY , 2010 .

[110]  Domenico Giardini,et al.  Geothermal quake risks must be faced , 2009, Nature.

[111]  K. Evans,et al.  Stress orientation to 5 km depth in the basement below Basel (Switzerland) from borehole failure analysis , 2009 .

[112]  Tobias Malte Müller,et al.  FAST TRACK PAPER: Microseismic signatures of non-linear pore-fluid pressure diffusion , 2009 .

[113]  D. Elsworth,et al.  Shear-induced dilatancy of fluid-saturated faults: Experiment and theory , 2009 .

[114]  Jacques R. Ernst,et al.  Earthquake focal mechanisms of the induced seismicity in 2006 and 2007 below Basel (Switzerland) , 2009 .

[115]  N. R. Warpinski,et al.  Microseismic Monitoring: Inside and Out , 2009 .

[116]  D. Wyborn,et al.  Investigation of Fault Mechanisms during Geothermal Reservoir Stimulation Experiments in the Cooper Basin, Australia , 2009 .

[117]  L. Murdoch,et al.  Introduction to Hydromechanical Well Tests in Fractured Rock Aquifers , 2009, Ground water.

[118]  Markus Häring,et al.  Characterisation of the Basel 1 enhanced geothermal system , 2008 .

[119]  Jonny Rutqvist,et al.  Mesoscale characterization of coupled hydromechanical behavior of a fractured-porous slope in response to free water-surface movement , 2008 .

[120]  Jonny Rutqvist,et al.  Analysis of Injection-Induced Micro-Earthquakes in a Geothermal Steam Reservoir, The Geysers Geothermal Field, California , 2008 .

[121]  D. Hill,et al.  Non-double-couple mechanisms of microearthquakes induced by hydraulic fracturing , 2008 .

[122]  K. Pruess.  Role of Fluid Pressure in the Production Behavior of EnhancedGeothermal Systems with CO2 as Working Fluid , 2008 .

[123]  Tsutomu Yamaguchi,et al.  The Hijiori Hot Dry Rock test site, Japan: Evaluation and optimization of heat extraction from a two-layered reservoir , 2008 .

[124]  A. Bunger,et al.  A Detailed Comparison of Experimental and Numerical Data on Hydraulic Fracture Height Growth Through Stress Contrasts , 2009 .

[125]  Domenico Giardini,et al.  Locally triggered seismicity in the central Swiss Alps following the large rainfall event of August 2005 , 2007 .

[126]  L. Murdoch,et al.  Removable Borehole Extensometers for Measuring Axial Displacements During Well Tests , 2007 .

[127]  Emmanuel M Detournay,et al.  Numerical Simulation of Hydraulic Fracturing in the Viscosity-Dominated Regime , 2007 .

[128]  D. Wyborn,et al.  Induced Seismicity during the Stimulation of a Geothermal hfr Reservoir in the Cooper Basin, Australia , 2006 .

[129]  Dominique Bruel,et al.  Numerical study of the impact of fluid density on the pressure distribution and stimulated volume in the Soultz HDR reservoir , 2006 .

[130]  K. Pruess.  Enhanced geothermal systems (EGS) using CO2 as working fluid - A novelapproach for generating renewable energy with simultaneous sequestration of carbon , 2006 .

[131]  C. Tsang,et al.  Field and numerical investigations of free-water surface oscillation effects on rock slope hydromechanical behaviour - Consequences for rock slope stability analyses , 2006 .

[132]  C. Tsang,et al.  Hydromechanical modeling of pulse tests that measure both fluid pressure and fracture-normal displacement of the Coaraze Laboratory site, France , 2006 .

[133]  J. Bommer,et al.  Control of hazard due to seismicity induced by a hot fractured rock geothermal project , 2006 .

[134]  C. Lévi-Strauss,et al.  Experimental investigation , 2013 .

[135]  M. Kubik.  The Future of Geothermal Energy , 2006 .

[136]  E. Lolon,et al.  Hydraulic Fracture Diagnostics Used To Optimize Development in the Jonah Field , 2006 .

[137]  M. Wyss,et al.  Variations in earthquake-size distribution across different stress regimes , 2005, Nature.

[138]  Albert Genter,et al.  Permeability creation and damage due to massive fluid injections into granite at 3.5 km at Soultz: 1. Borehole observations , 2005 .

[139]  Lisa V. Block,et al.  Deep-Injection and Closely Monitored Induced Seismicity at Paradox Valley, Colorado , 2005 .

[140]  K. Evans.  Permeability creation and damage due to massive fluid injections into granite at 3.5 km at Soultz: 2. Critical stress and fracture strength , 2005 .

[141]  H. Kaieda,et al.  Microseismic Monitoring of Hydraulic Stimulation at the Australian HDR Project in Cooper Basin , 2005 .

[142]  J. Willerson,et al.  LABORATORY INVESTIGATION , 2005 .

[143]  Hiroaki Niitsuma,et al.  Microseismicity and permeability enhancement of hydrogeologic structures during massive fluid injections into granite at 3 km depth at the Soultz HDR site , 2004 .

[144]  Andrew G. White,et al.  Semianalytical solutions for fluid flow in rock joints with pressure‐dependent openings , 2004 .

[145]  W. S. Phillips,et al.  Faulting Induced by Forced Fluid Injection and Fluid Flow Forced by Faulting: An Interpretation of Hydraulic-Fracture Microseismicity, Carthage Cotton Valley Gas Field, Texas , 2004 .

[146]  M. Saar,et al.  Depth dependence of permeability in the Oregon cascades inferred from hydrogeologic, thermal, seismic, and magmatic modeling constraints , 2004 .

[147]  F. Cornet,et al.  ISRM Suggested Methods for rock stress estimation; Part 3, Hydraulic fracturing (HF) and/ or hydraulic testing of pre-existing fractures (HTPF) , 2003 .

[148]  Li Li,et al.  The hydromechanical behaviour of a fracture: an in situ experimental case study , 2003 .

[149]  John A. Hudson,et al.  ISRM Suggested Methods for rock stress estimation: Part 4: Quality control of rock stress estimation , 2003 .

[150]  M. Saar,et al.  Seismicity induced by seasonal groundwater recharge at Mt. Hood, Oregon , 2003 .

[151]  V. M. Shmonov,et al.  Permeability of the continental crust: implications of experimental data , 2003 .

[152]  Jonny Rutqvist,et al.  The role of hydromechanical coupling in fractured rock engineering , 2003 .

[153]  Hans-Peter Harjes,et al.  A model for fluid-injection-induced seismicity at the KTB, Germany , 2003 .

[154]  J. Schmittbuhl,et al.  Fracture roughness and gouge distribution of a granite shear band , 2002 .

[155]  H. Lee,et al.  Hydraulic Characteristics of Rough Fractures in Linear Flow under Normal and Shear Load , 2002 .

[156]  Mofazzal Hossain,et al.  A shear‐dilation‐based model for evaluation of hydraulically stimulated naturally fractured reservoirs , 2002 .

[157]  B. Haimson,et al.  A laboratory study of hydraulic fracturing breakdown pressure in tablerock sandstone , 2001 .

[158]  Tsuyoshi Ishida,et al.  Acoustic emission monitoring of hydraulic fracturing in laboratory and field , 2001 .

[159]  D. Faulkner,et al.  Can the maintenance of overpressured fluids in large strike-slip fault zones explain their apparent weakness? , 2001 .

[160]  Nick Barton,et al.  An improved model for hydromechanical coupling during shearing of rock joints , 2001 .

[161]  S. Gentier,et al.  Role of Fracture Geometry in the Evolution of Flow Paths Under Stress , 2013 .

[162]  Zhixi Chen,et al.  An experimental investigation of hydraulic behaviour of fractures and joints in granitic rock , 2000 .

[163]  Hiroaki Niitsuma,et al.  Stress estimated using microseismic clusters and its relationship to the fracture system of the Hiji , 2000 .

[164]  Keisuke Ushijima,et al.  OGACHI HDR RESERVOIR EVALUATION BY AE AND GEOPHYSICAL METHODS , 2000 .

[165]  Robert G. Jeffrey,et al.  Caving Induced by Hydraulic Fracturing at Northparkes Mines , 2000 .

[166]  Sally M. Benson,et al.  Dynamics of fluids in fractured rock , 2000 .

[167]  M. Zoback,et al.  Stress and Permeability Heterogeneity within the Dixie Valley Geothermal Reservoir: Recent Results from Well 82-5 , 1999 .

[168]  R. Stein.  The role of stress transfer in earthquake occurrence , 1999, Nature.

[169]  Takatoshi Ito,et al.  Stress and rock mechanics issues of relevance to HDR/HWR engineered geothermal systems : review of developments during the past 15 years , 1999 .

[170]  R. Parker.  The Rosemanowes HDR project 1983–1991 , 1999 .

[171]  H. Kaieda,et al.  Current status of seismic and borehole measurements for HDR/HWR development , 1999 .

[172]  Yasuhiro Mitani,et al.  Development of a shear-flow test apparatus and determination of coupled properties for a single rock joint , 1999 .

[173]  S. Ingebritsen,et al.  Permeability of the continental crust: Implications of geothermal data and metamorphic systems , 1999 .

[174]  Robert W. Zimmerman,et al.  Effect of shear displacement on the aperture and permeability of a rock fracture , 1998 .

[175]  M. Zoback,et al.  Tectonic Controls on Fault-Zone Permeability in a Geothermal Reservoir at Dixie Valley, Nevada , 1998 .

[176]  S. Hickman,et al.  Reservoir-Scale Fracture Permeability in the Dixie Valley, Nevada, Geothermal Field , 1998 .

[177]  Hans-Peter Harjes,et al.  Source parameters of injection-induced microearthquakes at 9 km depth at the KTB Deep Drilling site, Germany , 1998, Bulletin of the Seismological Society of America.

[178]  F. Cornet,et al.  Seismic and Aseismic Slips Induced by Large-scale Fluid Injections , 1997 .

[179]  J. Lauterjung,et al.  The German Continental Deep Drilling Program KTB: Overview and major results , 1997 .

[180]  Hans-Peter Harjes,et al.  Injection-induced earthquakes and crustal stress at 9 km depth at the KTB deep drilling site, Germany , 1997 .

[181]  Leigh House,et al.  Detailed joint structure in a geothermal reservoir from studies of induced microearthquake clusters , 1997 .

[182]  R. J. Hopkirk,et al.  Observation and simulation of non‐Darcian flow transients in fractured rock , 1997 .

[183]  James P. Evans,et al.  Fault zone architecture and permeability structure , 1996 .

[184]  O. Stephansson,et al.  A cyclic hydraulic jacking test to determine the in situ stress normal to a fracture , 1996 .

[185]  M. Zoback,et al.  Fluid flow along potentially active faults in crystalline rock: Geology , 1995 .

[186]  J. Rutqvist.  Determination of hydraulic normal stiffness of fractures in hard rock from well testing , 1995 .

[187]  F. Schmitt,et al.  Scaling invariance of crack surfaces , 1995 .

[188]  Robert G. Jeffrey,et al.  A Comparison of Hydraulic Fracture Field Experiments, Including Mineback Geometry Data, with Numerical Fracture Model Simulations , 1995 .

[189]  O. Scotti,et al.  In Situ Evidence for fluid-induced aseismic slip events along fault zones , 1994 .

[190]  F. Cornet,et al.  Field Evidences on the Orientation of Forced Water Flow With Respect to the Regional Principal Stress Directions , 1994 .

[191]  V. Maury.  Rock failure mechanisms identification: A key for wellbore stability and reservoir behaviour problem , 1994 .

[192]  F. H. Cornet,et al.  Analysis of induced seismicity for fault zone identification , 1993 .

[193]  A. Jupe,et al.  Induced microseismicity and reservoir growth at the Fjällbacka hot dry rocks project, Sweden , 1992 .

[194]  M. Zoback,et al.  Stress orientation profile to 3.5 km depth near the San Andreas Fault at Cajon Pass, California , 1992 .

[195]  H. Gupta.  Reservoir-Induced Earthquakes , 1992 .

[196]  R. J. Hopkirk,et al.  THE EFFECTS OF FRACTURE NORMAL COMPLIANCE ON THE LONG TERM CIRCULATION BEHAVIOR OF A HOT DRY ROCK RESERVOIR: A PARAMETER STUDY USING THE NEW FULLY-COUPLED CODE 'FRACTURE' , 1992 .

[197]  Robert G. Jeffrey,et al.  An Analysis of Hydraulic Fracture and Mineback Data for a Treatment in the German Creek Coal Seam , 1992 .

[198]  M. S. Bruno,et al.  Pore pressure influence on tensile fracture propagation in sedimentary rock , 1991 .

[199]  Nikolas I. Christensen.  The German Continental Deep Drilling Program (KTB) , 1991 .

[200]  Terry E. Tullis,et al.  Euclidean and fractal models for the description of rock surface roughness , 1991 .

[201]  T. Esaki,et al.  Shear-flow Coupling Test On Rock Joints , 1991 .

[202]  Michael P. Cleary,et al.  IMPLICATIONS OF RECENT LABORATORY EXPERIMENTAL RESULTS FOR HYDRAULIC FRACTURES , 1991 .

[203]  D. A. Nicol,et al.  Modelling the heat extraction from the Rosemanowes HDR reservoir , 1990 .

[204]  B. Robinson,et al.  Modeling the hydraulic characteristics of the Fenton Hill, New Mexico Hot Dry Rock reservoir , 1990 .

[205]  Robert L. Wesson,et al.  Earthquake hazard associated with deep well injection: a report to the U.S. Environmental Protection Agency , 1990 .

[206]  T. W. Doe,et al.  Orientation of hydraulic fractures in salt under hydrostatic and non-hydrostatic stresses , 1989 .

[207]  R. Jung,et al.  Hydraulic in situ investigations of an artificial fracture in the Falkenberg granite , 1989 .

[208]  R. H. Parker.  Hot Dry Rock: Geothermal Energy : Phase 2B Final Report of the Camborne School of Mines Project , 1989 .

[209]  Chris Marone,et al.  The depth of seismic faulting and the upper transition from stable to unstable slip regimes , 1988 .

[210]  Robert L. Wesson,et al.  Earthquake hazard associated with deep well injection; a report to the U.S. Environmental Protection Agency , 1987 .

[211]  Rj Pine,et al.  A technical summary of phase 2b of the camborne school of mines HDR project, 1983–1986 , 1987 .

[212]  D. Evans,et al.  Laboratory Studies of Gas Flow Through a Single Natural Fracture , 1986 .

[213]  W. E. Warren,et al.  In situ stress estimates from hydraulic fracturing and direct observation of crack orientation , 1985 .

[214]  Norman R. Warpinski.  Measurement of Width and Pressure in a Propagating Hydraulic Fracture , 1985 .

[215]  K. Evans,et al.  Water table effects on the measurement of earth strain , 1984 .

[216]  Norman R. Warpinski,et al.  Influence of Geologic Discontinuities on Hydraulic Fracture Propagation (includes associated papers 17011 and 17074 ) , 1984 .

[217]  N. Barton,et al.  FUNDAMENTALS OF ROCK JOINT DEFORMATION , 1983 .

[218]  K. Evans,et al.  On the Development of Shallow Hydraulic Fractures as Viewed Through the Surface Deformation Field: Part 2-Case Histories , 1983 .

[219]  K. Evans,et al.  On the Development of Shallow Hydraulic Fractures as Viewed Through the Surface Deformation Field: Part 1-Principles , 1983 .

[220]  Roy Baria,et al.  Monitoring the effects of hydraulic stimulation by microseismic event location: A case study , 1983 .

[221]  Norman R. Warpinski,et al.  Laboratory Investigation on the -Effect of In-Situ Stresses on Hydraulic Fracture Containment , 1982 .

[222]  C. Pearson,et al.  The relationship between microseismicity and high pore pressures during hydraulic stimulation experiments in low permeability granitic rocks , 1981 .

[223]  James M. Duncan,et al.  LABORATORY STUDY OF HYDRAULIC FRACTURING , 1981 .

[224]  Chris Perason.  The Relationship Between Microseismicity and High Pore Pressures During Hydraulic Stimulation Experiments in Low Permeability Granitic Rocks , 1981 .

[225]  R. G. Cummings,et al.  Mining earth's heat: hot dry rock geothermal energy , 1979 .

[226]  J. Byerlee.  Friction of rocks , 1978 .

[227]  N. Barton,et al.  The shear strength of rock joints in theory and practice , 1977 .

[228]  Mark D. Zoback,et al.  Laboratory hydraulic fracturing experiments in intact and pre-fractured rock , 1977 .

[229]  J. Gale.  A numerical, field and laboratory study of flow in rocks with deformable fractures , 1977 .

[230]  J. Bredehoeft,et al.  An Experiment in Earthquake Control at Rangely, Colorado , 1976, Science.

[231]  A. McGarr,et al.  Seismic moments and volume changes , 1976 .

[232]  G. Richard,et al.  The mechanical properties of joints , 1974 .

[233]  William Walden Rubey,et al.  The Denver EarthquakeS. , 1968, Science.

[234]  J. C. Jaeger.  Extension failures in rocks subject to fluid pressure , 1963 .

[235]  William W Rubey,et al.  ROLE OF FLUID PRESSURE IN MECHANICS OF OVERTHRUST FAULTING I. MECHANICS OF FLUID-FILLED POROUS SOLIDS AND ITS APPLICATION TO OVERTHRUST FAULTING , 1959 .

[236]  A. F. Adams,et al.  The Survey , 2021, Dyslexia in Higher Education.

[237]  M. Biot.  General Theory of Three‐Dimensional Consolidation , 1941 .

[238]  R. Mendris,et al.  The link of {f(x, y) + zn = 0} and Zariski's conjecture , 2002, Compositio Mathematica.