Data generated from the Alum Innovative Exploration Project, one of several promising geothermal properties located in the middle to upper Miocene (~11-5 Ma, or million years BP) Silver Peak-Lone Mountain metamorphic core complex (SPCC) of the Walker Lane structural belt in Esmeralda County, west-central Nevada. The geothermal system at Alum is wholly concealed; its upper reaches discovered in the late 1970s during a regional thermal-gradient drilling campaign. The prospect boasts several shallow thermal-gradient (TG) boreholes with TG >75oC/km (and as high as 440oC/km) over 200-m intervals in the depth range 0-600 m. Possibly boiling water encountered at 239 m depth in one of these boreholes returned chemical- geothermometry values in the range 150-230oC. GeothermEx (2008) has estimated the electrical- generation capacity of the current Alum leasehold at 33 megawatts for 20 years; and the corresponding value for the broader thermal anomaly extending beyond the property at 73 megawatts for the same duration.
California State University Long Beach evaluated hydraulic connectivity among geothermal wells using Periodic Hydraulic Testing (PHT) and Distributed Acoustic Sensing (DAS). The principal was to create a pressure signal in one well and observe the responding pressure signals in one or more observation wells to assess the permeability and storage of the fracture network that connects the two wells. DAS measured strain at mHz frequency in monitoring wells in response to PHT.
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.
Processed SEGY files from the FutureGen2 project. Data includes 5 categories of OVSP data with 15 lines in each category (all in TWT). VSP data was processed from Sterling Seismic.
This Petrel project features geomechanical models that takes advantage of existing modeling work from PNNL and expands upon its framework to included overlying and underlying geologic zones. Where available, geomechanical logs were incorporated into these models. While the existing CO2 storage interval and caprock (Mt. Simon Ss and Eau Claire Shale) were finely layered by PNNL, the overlying layers were more coarsely layered to limit cell count.
This report compiles the results of geologic characterization of Task 3 (late-stage reef), Task 4 (active EOR reefs), and Task 5 (new EOR reefs) to demonstrate developed methodologies, geologic variability, and reservoir potential.
Comprehensive discussion of reservoir modeling studies that were conducted for tracking oil production, forecasting CO2 plume migration, and estimating associated storage in a number of reefs that were at different stages of their CO2-EOR life cycle.
Impact of layer thickness and well orientation on caprock integrity for geologic carbon storage
Processed SEGY files from the Perch 3D seismic area in the Michigan Basin. Data was used to make estimates of the stress field in the study area. Data was processed from Texseis, Inc.
The SEM in this Petrel project is based, in part, on an earlier model prepared at Battelle (1) that covers Michigan's Northern Pinnacle Reef trend. While the existing SEM focused on the Niagaran section, this Petrel project expands the framework to included overlying and underlying geologic zones. Where available, geomechanical logs were incorporated into the model.
The goal of Task 1-11 was to perform an initial assessment of the geologic storage capacity and injectivity of the Northern Fairway of Michigan’s Niagaran Reef Trend. This task included a regional assessment and mapping effort to understand the variability in the reef geology, fluid content, and reservoir parameters across the trend consisting of several hundred reefs.
The state of stress influences several potential risks associated with geologic carbon storage (GCS). Among these are the risk of induced seismicity and leakage due to unintentional hydraulic fracturing. In situ stress can be measured or inferred using several techniques, but these measurements are only made at discrete locations, and they generally provide an incomplete description of the full stress tensor. Because of this there is generally considerable uncertainty in the state of stress within a GCS reservoir and surrounding formations. The state of stress analysis tool (SOSAT) provides a method to use a Bayesian approach to calculate a probability distribution for in situ stress at a particular point using a variety of common data types. Using this stress state probability distribution, the SOSAT then calculates the probability of activating a critically-oriented fault at a specified range of pore pressures. The result is an easy to use physics-based tool for estimating the risk of induced seismicity and unintentional hydraulic fracturing.
This report describes research accomplishments achieved with funding provided through Department of Energy (DOE) Contract DE-FE0031686. The purpose of this DOE funding is to develop methods that can provide key information about stress fields that act on deep rocks without invading the earth to acquire that information. The research objective was to demonstrate methods that extract the azimuth directions of SHmax and SHmin stress in deep rocks from traditional seismic reflection data like the data that are used to explore for deep oil and gas reservoirs. Battelle performed two seismic investigations and achieved estimates of SHmax and SHmin azimuths in both efforts that agreed with local, non-seismic, ground-truth measurements of SHmax orientation. The first procedure utilized vertical seismic profiling (VSP) data; the second effort utilized three-dimensional (3D) seismic data.
This report presents a summary of Task 3 (Laboratory Experimental Characterization of Stress Dependent Wavespeed in Rocks and Application for In-Situ Stress Estimation) of the project titled “A Non-Invasive Approach for Elucidating the Spatial Distribution of In-Situ Stress in Deep Subsurface Geologic Formations Considered for CO2 Storage”. The main objective of this component of the project was to employ non-destructive techniques to determine how compressional (P)-wave and shear (S)-wave propagation velocities are related to triaxial-stress conditions in laboratory test samples of targeted reservoir rocks. The overarching principle is that such laboratory measurements can provide a basis whereby field measurements of wave-propagation velocities in rocks can be used to ascertain the stress state that would be expected to generate the observed wave-propagation behavior.
"This document presents a summary of TASK 4 (Field Testing) of the project entitled “A Non-Invasive Approach for Elucidating the Spatial Distribution of in-situ Stress in Deep Subsurface Geologic Formations Considered for CO2 Storage (FE0031686)”. This three-year project is part of the U.S. Department of Energy (DOE) National Energy Technology Laboratory (NETL) Carbon Storage program to research and address gaps that affect the economics of commercial CCS projects. One of these key gaps is the lack of certainty in predicting the geomechanical impacts of pressure migration due to CO2 injection into a storage complex. This report documents field testing that was conducted under TASK 4 to obtain input data needed to develop the site-specific geomechanical model in TASK 5 and to verify the model results (i.e. calculated stresses) for this site. The field work entailed collecting geophysical logs and core samples and conducting geomechanical stress tests in the Core Energy LLC State Otsego Lake (SOL 8-15A) well, located in Otsego County, Michigan."
This report describes research accomplishments achieved with funding provided through Department of Energy (DOE) Contract DE-FE0031686, for the project “A Non-Invasive Approach for Elucidating the Spatial Distribution of In Situ Stress in Deep Subsurface Geologic Formations Considered for CO2 Storage.” The purpose of this DOE funding is to develop non-invasive methods to obtain important information about subsurface stresses. The overall research goal of the project was to develop and improve methods for determining the spatial distribution of stresses, including magnitude and orientation of the three principal stress components in the subsurface, based on new methods that extract stress information from seismic data combined with well measurements, extended with well tests and logs, and unified in a numerical model that permits computation of the full stress tensor throughout the domains under investigation.
Laboratory Experiments Data of TASK3 of DOE project DE- FE0031686. Each signal has its own excel file. 150 signals are sent through the rock sample per each load configuration. There were approximately 50 to 150 load combinations tested during the experiments. Experiments were repeated after changing the polarity direction of the transducers. Signals of these repeats are in separate folders called "Reverse". There are three formations tested from the Michigan Core and four formations tested from the FutureGen site. The "Code" folder contains the Python code developed to analyze the signals. Large Dataset, please contact EDXSupport@netl.doe.gov
This is the final topical report for the Phase 2B Utah FORGE project, which is located near Roosevelt Hot Springs, Utah. This PDF format report details results associated with the conceptual geologic model, deep well 58-32, rock geomechanics, reservoir temperatures, seismic surveys, seismic monitoring, certainty, and NEPA. The report also provides an overview of all of the deliverables which were used to produce the results and full appendices.
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.
Routine and geomechanical well logs for 3 wells— State Otsego Lake 8-15A, Lawnichak 9-33, Chester 8-16.
EMI (Electric Micro Imaging tool, Halliburton) image log in GMI Imager format. GMI Imager is software available from Baker Hughes and is used to open .img files.
FMI image log and mud log of well 52B-7
Since October 2005, the Zama oil field in northwestern Alberta, Canada, has been the site of acid gas (approximately 80% CO2 and 20 H2S) injection for the simultaneous purpose of enhanced oil recovery (EOR), H2S disposal, and sequestration of CO2. Beginning in December 2006 and continuing through the present, injection has taken place at a depth of 1494 meters into one of over 800 pinnacle reef structures that have been identified in the Zama Subbasin. To date, over 36,000 metric tons of acid gas has been injected, resulting in incremental oil production over 25,000 barrels. Cost-effective monitoring at EOR sites that utilize H2S-rich acid gas as the sweep mechanism has been the overall goal of the project. The primary issues that have been addressed include (1) cap rock leakage, (2) long-term prediction of injectate, and (3) generation of data sets that will support the development and monetization of carbon credits. To address these issues, activities have been conducted at multiple scales of investigation in an effort to fully understand the ultimate implications of injection. Geological, geomechanical, geochemical, and engineering work has been used to fully describe the injection zone and adjacent strata in an effort to prove the long-term storage potential of this site. Through these activities, confidence in the ability of the Zama oil field to provide long-term containment of injected gas has been achieved. Results obtained from these activities can be applied not only to additional pinnacles in the Alberta Basin but to similar structures throughout the world.