This is a presentation on the Strain Sensing Array to Characterize Deformation at the FORGE Site project by Clemson University, presented by Lawrence Murdoch. The project's objective was to evaluate the feasibility of measuring and interpreting tensor strain data to improve the performance of EGS. This presentation was featured in the Utah FORGE R&D Annual Workshop on September 8, 2023. The workshop provided a valuable opportunity to explore the progress made in each of the 17 Research and Development projects funded under Solicitation 2020-1 which aim to enhance our understanding of the crucial factors influencing the development of Enhanced Geothermal Systems (EGS) reservoirs and resources.

This is a presentation on the Strain Sensing Array to Characterize Deformation at the FORGE Site project by Clemson University, presented by Lawrence Murdoch. The project's objective was to evaluate the feasibility of measuring and interpreting tensor strain data to improve the performance of EGS. This presentation was featured at the Utah FORGE R&D Annual Workshop on September 8, 2025. The workshop offered a valuable opportunity to review the progress of Research and Development projects funded under Solicitation 2020-1, which aim to improve our understanding of the key factors influencing Enhanced Geothermal System (EGS) reservoir and resource development.

This is a presentation on the Strain Sensing Array to characterize deformation at the FORGE site project by Clemson University, presented by Lawrence Murdoch. The project's objective was to evaluate the feasibility of measuring and interpreting tensor strain data to improve the performance of EGS. This presentation was featured in the Utah FORGE R&D Annual Workshop on August 23, 2024.

Core-based in-situ stress estimation, Triaxial Ultrasonic Velocity (labTUV) data, and Deformation Rate Analysis (DRA) data for Utah FORGE well 16A(78)-32 using triaxial ultrasonic velocity and deformation rate analysis. Report documenting a multi-component approach to characterizing in-situ stress at the U.S. DOE FORGE EGS site: laboratory, modeling and field measurement. Core-based methods for in-situ stress estimation were applied using samples from 5 intervals within the Utah FORGE 16A(78)-32 well. At three of these locations, Triaxial Ultrasonic Velocity (labTUV) tests were performed, resulting in experimentally-determined relationships between wave velocities and stresses. Non-monotonic increase in the velocity-stress relationships are inferred provide evidence of stress history and are therefore used to estimate in-situ stress magnitudes. Additionally, Deformation Rate Analysis (DRA) tests were run on core plugs from various orientations at each of the 5 sampling locations. These, too, provide evidence of stress history based on stress-strain behavior. A novel Weight of Evidence (WoE) method was developed as a means of synthesizing in-situ stress evidence from these two types of tests. Results indicate the minimum horizontal stress gradient ranges from 0.58 psi/ft to 0.69 psi/ft, with 4 of the 5 values between 0.66 psi/ft and 0.69 psi/ft. The vertical stress gradient ranges from 1.05 psi/ft to 1.12 psi/ft, with 4 of the 5 zones given results between 1.09 psi/ft and 1.12 psi/ft. The maximum horizontal stress gradient ranges from 0.98 psi/ft to 1.34 psi/ft, with 4 of the 5 zones falling between 0.98 psi/ft and 1.24 psi/ft. The stress regime thus appears to be on the edge between normal faulting and strike-slip faulting, potentially flipping back and forth between the two regimes due to variability of rock properties, structures such as faults, and/or thermal anomalies.

Core-based in-situ stress estimation, Triaxial Ultrasonic Velocity (labTUV) data, and Deformation Rate Analysis (DRA) data for Utah FORGE well 16A(78)-32 using triaxial ultrasonic velocity and deformation rate analysis. Report documenting a multi-component approach to characterizing in-situ stress at the U.S. DOE FORGE EGS site: laboratory, modeling and field measurement. Core-based methods for in-situ stress estimation were applied using samples from 5 intervals within the Utah FORGE 16A(78)-32 well. At three of these locations, Triaxial Ultrasonic Velocity (labTUV) tests were performed, resulting in experimentally-determined relationships between wave velocities and stresses. Non-monotonic increase in the velocity-stress relationships are inferred provide evidence of stress history and are therefore used to estimate in-situ stress magnitudes. Additionally, Deformation Rate Analysis (DRA) tests were run on core plugs from various orientations at each of the 5 sampling locations. These, too, provide evidence of stress history based on stress-strain behavior. A novel Weight of Evidence (WoE) method was developed as a means of synthesizing in-situ stress evidence from these two types of tests. Results indicate the minimum horizontal stress gradient ranges from 0.58 psi/ft to 0.69 psi/ft, with 4 of the 5 values between 0.66 psi/ft and 0.69 psi/ft. The vertical stress gradient ranges from 1.05 psi/ft to 1.12 psi/ft, with 4 of the 5 zones given results between 1.09 psi/ft and 1.12 psi/ft. The maximum horizontal stress gradient ranges from 0.98 psi/ft to 1.34 psi/ft, with 4 of the 5 zones falling between 0.98 psi/ft and 1.24 psi/ft. The stress regime thus appears to be on the edge between normal faulting and strike-slip faulting, potentially flipping back and forth between the two regimes due to variability of rock properties, structures such as faults, and/or thermal anomalies.

Report on possible geodetic signature of the 3 stimulations in April 2022 as well as a comparison with existing InSAR data gathered over the site before, during, and after the stimulation. In geothermal production it is important to understand the existing stress field and the changes in the stress associated with field development. The stress field is a controlling factor in the development and properties of natural and stimulated fractures. Furthermore, changes in the stress field can lead to associated seismicity and the potential for felt earthquakes. It is difficult to estimate stresses directly and they are typically inferred from well tests and observed strain. In this task our goal is to incorporate observed strain data into the fully integrated models of the stimulations at the FORGE site. FORGE project 3-2535 is planning on using a casing source EM method for detecting and imaging a deep localized stimulated fracture zone at the Utah FORGE site. Details on other stages of the project are included in the linked GDR submissions below.

This is a presentation on A Multi-Component Approach to Characterizing In-Situ Stress at the U.S DOE FORGE EGS Site: Laboratory, Modeling and Field Measurement project by Battelle [Columbus, OH], presented by Mark Kelley. The project's objective was to characterize stress in the Utah FORGE EGS reservoir using three methods: a laboratory rock-core stress estimation combined with a Machine Learning approach for estimation of in-situ stress from field sonic-log data, a field based in-situ measurement (min-frac) approach, and a modeling approach. This presentation was featured in the Utah FORGE R&D Annual Workshop on September 7, 2023. The workshop provided a valuable opportunity to explore the progress made in each of the 17 Research and Development projects funded under Solicitation 2020-1 which aim to enhance our understanding of the crucial factors influencing the development of Enhanced Geothermal Systems (EGS) reservoirs and resources.

The report provided here describes research activities between August 16th, 2018 and July 30th, 2024. The goals of the research activities are to conduct an Interferometric Synthetic Aperture Radar (InSAR) analysis and Ground Surface Deformation Modeling at the Utah FORGE site. InSAR data have been obtained from two satellite missions and combined pair-wise into interferograms to assess ground deformation. These InSAR datasets are compiled below as links to their respective destinations in the GDR. The project found that the InSAR data analyzed do not show any measurable deformation in the area immediately surrounding the FORGE wells and no vertical surface displacement that could be measurable by InSAR or GPS is expected from the stimulation experiments conducted at the site in 2023 or 2024. The report goes on to state the expected vertical displacement at the Earth's surface is less than 1 millimeter, based on modeling using an analytic solution. Hydromechanical modeling also predicts that the magnitude of the deformation produced by injection experiments is too small to be measured by InSAR or GPS.

The report provided here describes research activities between August 16th, 2018 and July 30th, 2024. The goals of the research activities are to conduct an Interferometric Synthetic Aperture Radar (InSAR) analysis and Ground Surface Deformation Modeling at the Utah FORGE site. InSAR data have been obtained from two satellite missions and combined pair-wise into interferograms to assess ground deformation. These InSAR datasets are compiled below as links to their respective destinations in the GDR. The project found that the InSAR data analyzed do not show any measurable deformation in the area immediately surrounding the FORGE wells and no vertical surface displacement that could be measurable by InSAR or GPS is expected from the stimulation experiments conducted at the site in 2023 or 2024. The report goes on to state the expected vertical displacement at the Earth's surface is less than 1 millimeter, based on modeling using an analytic solution. Hydromechanical modeling also predicts that the magnitude of the deformation produced by injection experiments is too small to be measured by InSAR or GPS.

Report on possible geodetic signature of the 3 stimulations in April 2022 as well as a comparison with existing InSAR data gathered over the site before, during, and after the stimulation. In geothermal production it is important to understand the existing stress field and the changes in the stress associated with field development. The stress field is a controlling factor in the development and properties of natural and stimulated fractures. Furthermore, changes in the stress field can lead to associated seismicity and the potential for felt earthquakes. It is difficult to estimate stresses directly and they are typically inferred from well tests and observed strain. In this task our goal is to incorporate observed strain data into the fully integrated models of the stimulations at the FORGE site. FORGE project 3-2535 is planning on using a casing source EM method for detecting and imaging a deep localized stimulated fracture zone at the Utah FORGE site. Details on other stages of the project are included in the linked GDR submissions below.