This paper describes the applications of the fractured continuum model to the different enhanced geothermal systems reservoir conditions. The capability of the fractured continuum model to generate fracture characteristics expected in enhanced geothermal systems reservoir environments are demonstrated for single and multiple sets of fractures. Fracture characteristics are defined by fracture strike, dip, spacing, and aperture. This paper demonstrates how the fractured continuum model can be extended to represent continuous fractured features, such as long fractures, and the conditions in which the fracture density varies within the different depth intervals. Simulations of heat transport using different fracture settings were compared with regard to their heat extraction effectiveness. The best heat extraction was obtained in the case when fractures were horizontal. A conventional heat extraction scheme with vertical wells was compared to an alternative scheme with horizontal wells. The heat extraction with the horizontal wells was significantly better than with the vertical wells when the injector was at the bottom.
This layer traces apparent topographic and air-photo lineaments in the area around Pagosa springs in Archuleta County, Colorado. It was made in order to identify possible fault and fracture systems that might be conduits for geothermal fluids. Geothermal fluids commonly utilize fault and fractures in competent rocks as conduits for fluid flow. Geothermal exploration involves finding areas of high near-surface temperature gradients, along with a suitable plumbing system that can provide the necessary permeability. Geothermal power plants can sometimes be built where temperature and flow rates are high. To do this, georeferenced topographic maps and aerial photographs were utilized in an existing GIS, using ESRI ArcMap 10.0 software. The USA_Topo_Maps and World_Imagery map layers were chosen from the GIS Server at server.arcgisonline.com, using a UTM Zone 13 NAD27 projection. This line shapefile was then constructed over that which appeared to be through-going structural lineaments in both the aerial photographs and topographic layers, taking care to avoid manmade features such as roads, fence lines, and right-of-ways. These lineaments may be displaced somewhat from their actual location, due to such factors as shadow effects with low sun angles in the aerial photographs. Note: This shape file was constructed as an aid to geothermal exploration in preparation for a site visit for field checking. We make no claims as to the existence of the lineaments, their location, orientation, and nature.
This submission includes synthetic seismic modeling data for the Push-Pull project at Brady Hot Springs, NV. The synthetic seismic is all generated by finite-difference method regarding different fracture and rock properties.
This resource contains data on active faults in California that are believed to be sources of M>6 earthquakes during the Quaternary (the past 1,600,000 years). This resource is a compilation of Quaternary Active Fault features compiled by the USGS in cooperation with the California Geological Survey and accessed on July 11, 2012 by the AZGS. The Quaternary Fault and Fold Database for the Nation can be accessed online at http://earthquake.usgs.gov/qfaults/ through a user-friendly interface developed by the U.S. Geological Survey. This is part of the first nationwide compilation to provide up-to-date and comprehensive geologically based information on known or suspected active faults. The data are available as a Web feature service, a Web map service, an ESRI Service Endpoint, and an Excel workbook for the National Geothermal Data System. Each feature in an active fault dataset (record or row in the worksheet) is characterized by a unique combination of features, as well as being physically connected or inferred to be connected spatially in the Earth. For mapped active faults, the deformation style is assumed to be brittle (as opposed to ductile). The workbook contains 6 worksheets, including information about the template, instructions on using the template, notes related to revisions of the template, resource provider information, the data, a field list (data mapping view), and vocabularies (data valid terms) used to populate the spreadsheet. Fields in the data table include FeatureURI, Name, FullName, ParentFeatureURI, Label, Description, Symbol, OtherID, SpecificationURI, FeatureType, GeologicHistory, RepresentativeAgeURI, YoungerAgeURI, OlderAgeURI, IntervalSince Movement, Shape, ObservationMethod, PositionAccuracyMeters, PositionAccuracy, Displacement, SlipRate, SlipAccumulationInterval, MovementType, MovementSense, DipDirection, DateMostRecentEvent, RecurrenceInterval, TotalSlip, Source and MetadataURI.--NGDS
Includes test data from Confined Brazilian Tests. The tests were aim at investigating the rock failure envelope of four different lithologies including Indiana limestone, Scioto sandstone, Grey Berea sandstone, and Tennessee sandstone. Tables include the strength data obtained using load and damage controlled Brazilian tests on the six lithologies. Confine Brazilian tests are preformed by wrapping a sample in a copper jacket so that the confining fluid does not directly interact with the sample. Then a constant confining pressure is applied to the fluid to create a state of triaxial stress in the disc such that the disc center is under three nonzero and unequal principal stress components. By increasing the confining pressure, the least principal stress changes from tensile to compressive so that rock failure can be investigated over a wide range of stress conditions.
Directional Cooling-Induced Fracturing (DCIF) experiments were conducted on three rectangular Westerly granite blocks (width=depth=4.0", height=2.0") which were preheated to 200, 400, and 600 degree C to induce damage (microcracks) with varying degrees. Liquid nitrogen was poured in a small, 1"-diameter copper cup attached to the top of the sample, and the resulting acoustic emissions (AEs) and temperature changes on the surface of the sample were monitored. The experiments were conducted under one selected biaxial stress (5.8MPa). The obtained AEs were used to determine the microcracking source locations and amplitude, and the associated moment tensors. The onset time of the AEs was correlated with the cooling temperature, which was used to show that the temperature at the onset of microcracking is not affected significantly by the preexisting damage, compared to the impact of the stress in the sample. Included in this submission are the animations of the AE locations and graphics displaying the measured temperature-AE activity changes for samples with different degrees of microcrack damage.
Directional Cooling-Induced Fracturing (DCIF) experiments were conducted on rectangular Westerly granite blocks (width=depth=4.0", height=2.0"). Liquid nitrogen was poured in a small, 1"-diameter copper cup attached to the top of the sample, and the resulting acoustic emissions (AEs) and temperature changes on the surface of the sample were monitored. Several confining stresses were applied bi-axially to the sides of the samples so that the onset of AE activity and the stress applied to the sample were correlated. The obtained AEs were used to determine the microcracking source locations and amplitude, and the associated moment tensors. Included in this submission are the animations of the AE locations and graphics displaying the measured temperature-AE activity changes for different stresses.
Understanding the relationship between stress state, strain state and fracture initiation and propagation is critical to the improvement of fracture simulation capability if it is to be used as a tool for guiding hydraulic fracturing operations. The development of fracture prediction tools is especially critical for geothermal applications such as EGS because the opportunities to build understanding empirically will be limited due to the high costs associated with field trials. There is a significant body of experimental work associated with hydraulic fracture investigation, but past efforts are typically hampered by an inability to accurately and comprehensively measure strains within the sample mass near critical regions of interest. This work aims to develop non-destructive neutron diffraction based strain measurement techniques that can be used to interrogate the internal volume of geological specimens subjected to tri-axial stress states resembling geothermal application conditions. Demonstrating the ability of the technique to generate useful quantitative data is the primary focus at this stage of the effort. Details of the experimental setup and diffraction technique will be presented in this communication, including the description of a custom designed high-pressure, neutron scattering
Directional Cooling-Induced Fracturing (DCIF) experiments were conducted on a short, cylindrical sample of Westerly granite (diameter = 4 inches, height ~ 2 inches). Liquid nitrogen was poured in a copper cup attached to the top of the sample, and the resulting acoustic emissions (AEs) and temperature changes on the surface of the sample were monitored. The obtained AEs were used to determine the microcracking source locations and amplitude, and the associated moment tensors. Included in this submission is an animation of the AEs, a graphic displaying the temperature changes, and the measured data.
The solid Earth strains in response to the gravitational pull from the Moon, Sun, and other planetary bodies. Measuring the flexure of geologic material in response to these Earth tides provides information about the geomechanical properties of rock and sediment. Such measurements are particularly useful for understanding dilation of faults and fractures in competent rock. A new approach to measuring earth tides using fiber optic distributed acoustic sensing (DAS) is presented here. DAS was originally designed to record acoustic vibration through the measurement of dynamic strain on a fiber optic cable. Here, laboratory experiments demonstrate that oscillating strain can be measured with DAS in the microHertz frequency range, corresponding to half-day (M2) lunar tidal cycles. Although the magnitude of strain measured in the laboratory is larger than what would be expected due to earth tides, a clear signal at half-day period was extracted from the data. With the increased signal-to-noise expected from quiet field applications and improvements to DAS using engineered fiber, earth tides could potentially be measured in deep boreholes with DAS. Because of the distributed nature of the sensor (0.25 m measurement interval over kilometers), fractures could be simultaneously located and evaluated. Such measurements would provide valuable information regarding the placement and stiffness of open fractures in bedrock. Characterization of bedrock fractures is an important goal for multiple subsurface operations such as petroleum extraction, geothermal energy recovery, and geologic carbon sequestration.
This package includes data and footage from two rounds of downhole camera surveys performed at the Sanford Underground Research Facility (SURF) on the 4850 level. The exercise was performed once on 25 May 2018 and once on 21 December 2018. On May 25th, the first round was done during fluid injection at the 164-ft stimulation zone in the injection well (E1-I). On December 21st, the second round was carried out during fluid injection at the 142-ft stimulation zone. Prior to the injections, downhole instrumentation was removed from the production well (E1-P) to allow room for the downhole camera system. The water within E1-P was then lifted out by the application of air pressure and the downhole camera system was conveyed into the production well. Finally, the water was injected into E1-I and the camera was used to scan for jetting points, or fluid entry, in E1-P. There is a survey description in this package that further describes the procedure of the survey and the overall results. Additionally, there is a detailed analysis of the surveys in the form of a PowerPoint, which includes animations/visualizations from the camera footage, presents interpretations in detail, and provides some general conclusions. Three animations, along with the two video segments that show the jetting into E1-P, are also provided. The video footage was collected using a GeoVISION Dual-Scan Micro Video Camera, the specs of which are also included in this package as a resource.
Core logs from the EGS Collab project Experiment 1 for the stimulation (Injection) well (E1-I), the Production well (E1-P), and monitoring wells (E1-OT, E1-OB, E1-PST, E1-PSB, E1-PDT, and E1-PDB) on the 4850 Level of SURF (the Sanford Underground Research Facility), single PDF file, 5-ft run intervals. In the monitoring well IDs, "O" indicates that the well is orthogonal to the anticipated fracture plane, "P" indicates that the well is parallel to the anticipated fracture plane, "S" indicates a shallow well, "D" indicates a deep well, "T" refers to top, and "B" refers to bottom. Logs include: experiment number; borehole ID; depth interval; run number; final packed core box number; scribe line (yes/no; red-on-right convention); logging dates; logger initials; as well as sketches of core foliation, folding, and fracturing with additional details and notes on other features of interest.
Characterizing the stimulation mode of a fracture is critical to assess the hydraulic efficiency and the seismic risk related to deep fluid manipulations. We have monitored the three-dimensional displacements of a fluid-driven fracture during water injections in a borehole at ~1.5 km depth in the crystalline rock of the Sanford Underground Research Facility (USA). The fracture initiates at 61% of the minimum horizontal stress by micro-shearing of the borehole on a foliation plane. As the fluid pressure increases further, borehole axial and radial displacements increase with injection time highlighting the opening and sliding of a new hydrofracture growing ~10 m away from the borehole, in accordance with the ambient normal stress regime and in alignment with the microseismicity. Our study reveals how fluid-driven fracture stimulation can be facilitated by a mixed-mode process controlled by the complex hydromechanical evolution of the growing fracture. The data presented in this submission refer to the SIMFIP measurements and analyses of the stimulation tests conducted on the 164 ft (50 m) notch of the Sanford Underground Research Facility (SURF), during the EGS-Collab test 1. In addition to the datafiles, there is the draft of a manuscript submitted to Geophysical Research Letters (GRL).
This package includes data and models that support hydraulic fracture stimulation and fluid circulation experiments in the Sanford Underground Research Facility (SURF). A paper by Schwering et al. (2020) describes the deterministic basis for developing a "common" discrete fracture network (CDFN) model of significant natural fractures in EGS Collab Testbed 1 on the 4850-Level of SURF. The ReadMe for this model shows drift, wells, scanlines, fracture data, interpreted fractures, and geophysical visualizations. There is also a summary of the data that was used in this experiment and includes results from reviewing core, televiewer (TV) logs, core-TV depth/feature registration, and from mapping weeps in the 4850-Level drift. The CDFN is intended to be a baseline model of the pre-stimulated testbed (though some observations from stimulation helped inform the model).
Mixed wireline logs including both cased and open hole logs. Data sets are PDS, LAS, and excel files that commonly contain multiple logs. Types of wireline logs include gamma ray, neutron porosity, photoelectric, sonic, mineral volume, ELAN, FMI, cement bond logs, magnetic resonance, and laterolog.
Mixed wireline logs including both cased and open hole logs. Data sets are PDS, LAS, and excel files that commonly contain multiple logs. Types of wireline logs include gamma ray, neutron porosity, photoelectric, sonic, mineral volume, ELAN, FMI, cement bond logs, magnetic resonance, and laterolog.
Chen, X., Eichhubl, P., Olson, J. E., 2017, Effect of water on critical and subcritical fracture properties of Woodford shale, Journal of Geophysical Research-Solid Earth, v. 122, 2736-2750. http://dx.doi.org/10.1002/2016JB013708 .
The submission contains a .xls files consisting of 10 excel sheets, which contain combined list of pressure, saturation, salinity, temperature profiles from the simulation of CO2 push-pull using Brady reservoir model and the corresponding effective compressional and shear velocity, bulk density, and fluid and time-lapse neutron capture cross section profiles of rock at times 0 day (baseline) through 14 days. First 9 sheets (each named after the corresponding CO2 push-pull simulation time) contains simulated pressure, saturation, temperature, salinity profiles and the corresponding effective elastic and neutron capture cross section profiles of rock matrix at the time of CO2 injection. Each sheet contains two sets of effective compressional velocity profiles of the rock, one based on Gassmann and the other based on Patchy saturation model. Effective neutron capture cross section calculations are done using a proprietary neutron cross-section simulator (SNUPAR) whereas for the thermodynamic properties of CO2 and bulk density of rock matrix filled with fluid, a standalone fluid substitution tool by Schlumberger is used. Last sheet in the file contains the bulk modulus of solid rock, which is inverted from the rock properties (porosity, sound speed etc) based on Gassmann model. Bulk modulus of solid rock in turn is used in the fluid substitution.
FRACGEN/NFFLOW is a DOE sponsored project to simulate the behavior of tight, fractured, strata-bound reservoirs that arise from irregular, discontinuous, or clustered networks of fractures. This distribution includes the PC programs and user interfaces for fracture network generation, discrete fracture reservoir simulation, and visualization of fracture networks and reservoir performance. New features in this release are optional fixed pressure boundary conditions, permeable unfractured layers, liquid data handling, sorption, and stress sensitive aperture modeling.
NICHOLAS COMBS NO. 7239 WELL, HAZARD, KENTUCKY
This dataset contains a variety of data about the Fort Bliss geothermal area, part of the southern portion of the Tularosa Basin, New Mexico. The dataset contains schematic models for the McGregor Geothermal System, a shallow temperature survey of the Fort Bliss geothermal area. The dataset also contains Century OH logs, a full temperature profile, and complete logs from well RMI 56-5, including resistivity and porosity data, drill logs with drill rate, depth, lithology, mineralogy, fractures, temperature, pit total, gases, and descriptions among other measurements as well as CDL, CNL, DIL, GR Caliper and Temperature files. A shallow (2 meter depth) temperature survey of the Fort Bliss geothermal area with 63 data points is also included. Two cross sections through the Fort Bliss area, also included, show well position and depth. The surface map included shows faults and well spatial distribution. Inferred and observed fault distributions from gravity surveys around the Fort Bliss geothermal area.
In these data sets, the experiment time, actual date and time, room temperature, sample temperature, upstream and downstream pressures (measured independently), corrected differential pressure (measured independently and corrected for offset and room temperature) indication of aperture closure by linear variable differential transformer are presented. An indication of the sample is in the file name and in the first line of data.
The primary objective of this research is to understand how different rock types, mineral and fluid compositions, and fracture surface textures determine the longevity of fracture apertures, so that selection of reservoir rock can be economically optimized to reduce future refracturing. We are performing laboratory tests to study this in a custom apparatus at conditions relevant to EGS, with temperatures up to 250 degrees C (design maximum 300 degrees C). Our approach is to perform a number of long term (up to several months) laboratory experiments using relevant rock samples with different mineralogies to explore fracture sustainability under EGS conditions. We use an apparatus that allows direct application of a normal force on the fracture faces of a single fracture in a sample having a sheared, tensile fracture. We flow brine of a specified composition through the aperture, and simultaneously measure the fracture permeability and closure. We collect the effluent water for chemical and isotopic analysis. We are numerically modeling our tests and comparing experimental and numerical results. This submission includes photomicrographs of pre-test (unreacted) and post-test (reacted) samples from Brady well BCH-03 at various depths, Desert Peak well DP 35-13, and samples of Stripa granite. The photomicrographs are provided using uncrossed and crossed polarized light (xpl). UN is uncrossed nicols, CN and xpl are crossed nicols (crossed polars). The magnification listed is just referring to the objective lens that was used, not the total magnification of the images. With a 5x objective, the bottom dimension of an image is 1.75 mm. With 10x the bottom dimension of an image is 0.875 mm, and with 2x the bottom dimension of an image is 4.375 mm.
The link points to a website at NCEDC to download the full moment tensors inversion software The moment tensor analysis conducted in the current project is based on the full moment tensor model described in Minson and Dreger (2008). The software including source, examples and tutorial can be obtained from ftp://ncedc.org/outgoing/dreger (download file pasi-nov282012.tar.gz). Performance criteria, mathematics and test results are provided by Minson and Dreger (2008), Ford et al. (2008, 2009, 2010, 2012) and Saikia (1994). References: Ford, S., D. Dreger and W. Walter (2008). Source Characterization of the August 6, 2007 Crandall Canyon Mine Seismic Event in Central Utah, Seism. Res. Lett., 79, 637-644. Ford, S. R., D. S. Dreger and W. R. Walter (2009). Identifying isotropic events using a regional moment tensor inversion, J. Geophys. Res., 114, B01306, doi:10.1029/2008JB005743. Ford, S. R., D. S. Dreger and W. R. Walter (2010). Network sensitivity solutions for regional moment tensor inversions, Bull. Seism. Soc. Am., 100, p. 1962-1970. Ford, S. R., W. R. Walter, and D. S. Dreger (2012). Event discrimination using regional moment 665 tensors with teleseismic-P constraints, Bull. Seism. Soc. Am. 102, 867-872. Minson, S. and D. Dreger (2008), Stable Inversions for Complete Moment Tensors, Geophys. J. Int., 174, 585-592. Saikia, C.K. (1994), Modified Frequency-Wavenumber Algorithm for Regional Seismograms using Filons Quadrature: Modeling of Lg Waves in Eastern North America. Geophys. J. Int., 118, 142-158.
Further Development of a Fracture Model for Lenticular Gas Sands, Final Report; April 1985
This data submission includes several data components that were used to develop a conceptual model and power capacity-estimates of two low-temperature geothermal resources that define geothermal prospect A at Hawthorne, Nevada. Data are sourced from a combination of legacy publicly-available data and more recent data acquisition conducted by the US Navy Geothermal Program Office (2008-2013) and the Great Basin Center for Geothermal Energy at the University of Nevada, Reno (2008-2010). Data sets include compiled fluid geochemistry data, down-hole temperature logs for wells in the vicinity of prospect A, 2 meter temperature survey data, temperature-spinner logs acquired in well HWAAD-2A, fracture picks from image log data acquired in wells HWAAD-2 and HWAAD-3, and X-Ray Diffraction (XRD) analyses on cuttings from wells HWAAD-2A and HWAAD-3. These data have been reviewed for errors and inconsistencies, but it is possible that few errors could still remain. The resource conceptual model and power capacity estimates are included in the final report to the US Department of Energy, and are presented in a manuscript by Ayling and Hinz. A link to the manuscript published in Geothermics is linked below in this submission.
A presentation with notes showing an overview of the last 6 months of the project on high-temperature self-healing inorganic cement composites. General approach, test methods and results for the self-healing cement composites are presented. Data include strength recoveries for 9 cement composites in three curing environments (water, alkali carbonate, brine) at 300 degC, bond strength measurements for cement/carbon steel samples, thermal shock tests, performance of healing aids. The presentation was shown during the joint SPE/GRC workshop on March 22 in San Diego, California
Images of the Stripa Granite core before and after the fracture sustainability test. Photos of fracture faces of Stripa Granite core.
Effective enhanced geothermal systems (EGS) require optimal fracture networks for efficient heat transfer between hot rock and fluid. Microseismic mapping is a key tool used to infer the subsurface fracture geometry. Traditional earthquake detection and location techniques are often employed to identify microearthquakes in geothermal regions. However, most commonly used algorithms may miss events if the seismic signal of an earthquake is small relative to the background noise level or if a microearthquake occurs within the coda of a larger event. Consequently, we have developed a set of algorithms that provide improved microearthquake detection. Our objective is to investigate the microseismicity at the DOE Newberry EGS site to better image the active regions of the underground fracture network during and immediately after the EGS stimulation. Detection of more microearthquakes during EGS stimulations will allow for better seismic delineation of the active regions of the underground fracture system. This improved knowledge of the reservoir network will improve our understanding of subsurface conditions, and allow improvement of the stimulation strategy that will optimize heat extraction and maximize economic return.
Effective enhanced geothermal systems (EGS) require optimal fracture networks for efficient heat transfer between hot rock and fluid. Microseismic mapping is a key tool used to infer the subsurface fracture geometry. Traditional earthquake detection and location techniques are often employed to identify microearthquakes in geothermal regions. However, most commonly used algorithms may miss events if the seismic signal of an earthquake is small relative to the background noise level or if a microearthquake occurs within the coda of a larger event. Consequently, we have developed a set of algorithms that provide improved microearthquake detection. Our objective is to investigate the microseismicity at the DOE Newberry EGS site to better image the active regions of the underground fracture network during and immediately after the EGS stimulation. Detection of more microearthquakes during EGS stimulations will allow for better seismic delineation of the active regions of the underground fracture system. This improved knowledge of the reservoir network will improve our understanding of subsurface conditions, and allow improvement of the stimulation strategy that will optimize heat extraction and maximize economic return.
This a report for the project "Mapping Fracture Network Creation with Microseismicity During EGS Demonstrations". Effective enhanced geothermal systems (EGS) require optimal fracture networks for efficient heat transfer between hot rock and fluid. Microseismic mapping is a key tool used to infer the subsurface fracture geometry. Traditional earthquake detection and location techniques are often employed to identify microearthquakes in geothermal regions. However, most commonly used algorithms may miss events if the seismic signal of an earthquake is small relative to the background noise level or if a microearthquake occurs within the coda of a larger event. Consequently, we have developed a set of algorithms that provide improved microearthquake detection. Our objective is to investigate the microseismicity at the DOE Newberry EGS site to better image the active regions of the underground fracture network during and immediately after the EGS stimulation. Detection of more microearthquakes during EGS stimulations will allow for better seismic delineation of the active regions of the underground fracture system. This improved knowledge of the reservoir network will improve our understanding of subsurface conditions, and allow improvement of the stimulation strategy that will optimize heat extraction and maximize economic return. This project is the FY14 continuation of FY13 AOP project 25728, which had its origins as the ARRA lab project AID 19981.
The objective of this project is to detect and locate microearthquakes to aid in the characterization of reservoir fracture networks. Accurate identification and mapping of the large numbers of microearthquakes induced in EGS is one technique that provides diagnostic information when determining the location, orientation and length of underground crack systems for use in reservoir development and management applications. Conventional earthquake location techniques often are employed to locate microearthquakes. However, these techniques require labor-intensive picking of individual seismic phase onsets across a network of sensors. For this project we adapt the Matched Field Processing (MFP) technique to the elastic propagation problem in geothermal reservoirs to identify more and smaller events than traditional methods alone.
Impact of layer thickness and well orientation on caprock integrity for geologic carbon storage
Numerical Model of Massive Hydraulic Fracture. Final report; March 1985
This file contains a list of relevant references on the Biot theory (forward and inverse approaches), the double-porosity and dual-permeability theory, and seismic wave propagation in fracture porous media, in RIS format, to approach seismic monitoring in a complex fractured porous medium such as Brady's Geothermal Field.
Rock Matrix and Fracture Analysis of Flow in Western Tight Gas Sands; December 1987
This submission contains 167 deviatoric moment tensor (MT) solutions for the seismicity observed two years prior and three years post start of injection activities at The Geysers Prati 32 EGS Demonstration. Also included is a statistical representation of the properties of 751 fractures derived from the analysis of seismicity observed two years prior and three years post start of injection activities at The Geysers Prati 32 EGS Demonstration Project. The locations of the fractures are taken from microseismic hypocenters, the fracture areas are derived from moment magnitudes via scaling relationships, and the azimuths (sigma 1) and dips (sigma 3) are derived from the results of stress analyses.
This submission contains 167 full moment tensor (MT) solutions for the seismicity observed two years prior and three years post start of injection activities. Also included are the azimuth and plunge angles for the three main stress directions sigma1, sigma 2 and sigma 3 at the Prati32 EGS demonstration site in the northwest Geysers geothermal reservoir. The data are divided into 15 time periods spanning a range of five years, including two years prior to start of injection until three years post start of injection activities.
Spreadsheet containing the raw measured data, calibrated data, and brief explanation of data for Test1 Stripa Granite Geomechanical/Geochemical Test. Stress on fracture ~20.7 MPa.
Input and output files used for fault characterization through numerical simulation using iTOUGH2. The synthetic data for the push period are generated by running a forward simulation (input parameters are provided in iTOUGH2 Brady GF6 Input Parameters.txt [InvExt6i.txt]). In general, the permeability of the fault gouge, damage zone, and matrix are assumed to be unknown. The input and output files are for the inversion scenario where only pressure transients are available at the monitoring well located 200 m above the injection well and only the fault gouge permeability is estimated. The input files are named InvExt6i, INPUT.tpl, FOFT.ins, CO2TAB, and the output files are InvExt6i.out, pest.fof, and pest.sav (names below are display names). The table graphic in the data files below summarizes the inversion results, and indicates the fault gouge permeability can be estimated even if imperfect guesses are used for matrix and damage zone permeabilities, and permeability anisotropy is not taken into account.
Well data for the INEL-1 well located in eastern Snake River Plain, Idaho. This data collection includes caliper logs, lithology reports, borehole logs, temperature at depth data, neutron density and gamma data, full color logs, fracture analysis, photos, and rock strength parameters for the INEL-1 well. This collection of data has been assembled as part of the site characterization data used to develop the conceptual geologic model for the Snake River Plain site in Idaho, as part of phase 1 of the Frontier Observatory for Research in Geothermal Energy (FORGE) initiative. They were assembled by the Snake River Geothermal Consortium (SRGC), a team of collaborators that includes members from national laboratories, universities, industry, and federal agencies, lead by the Idaho National Laboratory (INL).
This paper documents our effort to use a fully coupled hydro-geomechanical numerical test bed to study using low hydraulic pressure to stimulate geothermal reservoirs with existing fracture network. In this low pressure stimulation strategy, fluid pressure is lower than the minimum in situ compressive stress, so the fractures are not completely open but permeability improvement can be achieved through shear dilation. We found that in this low pressure regime, the coupling between the fluid phase and the rock solid phase becomes very simple, and the numerical model can achieve a low computational cost. Using this modified model, we study the behavior of a single fracture and a random fracture network.
This is an analysis of the pressure falloff in stage 1 fracture stimulation of FORGE well 16A(78)-32. The objective of this research is to understand the information content of the well stimulation data of FORGE Well 16A(78)-32. The Stage 1 step-rate test, a variant of the classic diagnostic fracture injection test (DFIT), contains valuable information about the success of well fracturing and the nature of resulting formation stimulation in the drainage volume of Well 16A(78). The analysis we have provided is based on the classic pressure transient analysis in petroleum reservoirs. The next step in the analysis is to use the information we have discovered in the analysis of tracer flowback data. This set of slides we have provided includes the pressure falloff analysis of the data recorded during stimulation of Stage 1 in injection Well 16A(78)-32 conducted in April of 2022. To honor multiple rate a superposition approach for linear flow regime was applied. The analysis yielded a permeability two orders of magnitude larger than permeability from cores. Our calculated permeability is essentially the effective permeability of micro- and macro-fracture system in the stimulated volume of the Well 16A(78)-32. Another observation is that after using the classic G-function plot, no closure stress was observed. This could suggest that pre-existing natural fractures were reopened during stimulation and yet had no propensity to close in accordance to the poroelastic properties.
This data set includes the daily drilling reports and Pason data for well 78B-32 and Schlumberger logs acquired after drilling completion. This well was drilled between June 27th and July 31st of 2021. Also included is raw and processed data for a variety of well data metrics including temperature, porosity, density, and sonic data. This data was taken at the Utah FORGE site as part of the Utah FORGE project.
This submission includes a shapefile of the Opal Mound Fault, and multiple datasets of lineaments mapped in the Mineral Mountains which overlook the Utah FORGE site, hyperlinked to rose diagrams in a polygon grid shapefile.
Six samples were evaluated in unconfined and triaxial compression, their data are included in separate excel spreadsheets, and summarized in the word document. Three samples were plugged along the axis of the core (presumed to be nominally vertical) and three samples were plugged perpendicular to the axis of the core. A designation of "V"indicates vertical or the long axis of the plugged sample is aligned with the axis of the core. Similarly, "H" indicates a sample that is nominally horizontal and cut orthogonal to the axis of the core. Stress-strain curves were made before and after the testing, and are included in the word doc. The confining pressure for this test was 2800 psi. A series of tests are being carried out on to define a failure envelope, to provide representative hydraulic fracture design parameters and for future geomechanical assessments. The samples are from well 52-21, which reaches a maximum depth of 3581 ft +/- 2 ft into a gneiss complex.
Natural fracture data from wells 33-7, 33A-7,52A-7, 52B-7 and 83-11 at West Flank. Fracture orientations were determined from image logs of these wells (see accompanying submissions). Data files contain depth, apparent (in wellbore reference frame) and true (in geographic reference frame) azimuth and dip, respectively.
This dataset is a compilation of fault (shear displacement) features throughout West Virginia, provided by the West Virginia Geological and Economic Survey (WVGES), published as a web feature service, a web map service, an ESRI service and an Excel workbook.The workbook contains 16 worksheets, including information about the template, notes related to revisions of the template, resource provider information, the data, a field list (data mapping view), and various sheets indicating valid terms and URIs for this information exchange. For mapped active faults, which are the scope of this scheme, the deformation style is assumed to be brittle (as opposed to ductile). For more info about this resource please see the links provided (shapefiles and metadata URLs). This resource was provided by the West Virginia Geological and Economic Survey and made available for distribution through the National Geothermal Data System. --NGDS