Utah FORGE 2439: A Multi-Component Approach to Characterizing In-Situ Stress

Description

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.

Resources

Name Format Description Link
33 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 (TUV) tests were performed, resulting in experimentally-determined relationships between wave velocities and stresses.Additionally, Deformation Rate Analysis (DRA) tests were run on core plugs from various orientations at each of the 5 sampling locations. More information in the document. https://gdr.openei.org/files/1438/Pitt-Battelle%202439%20Milestone%202.1%20Report%20For%20Submission.pdf
57 Triaxial Ultrasonic Velocity (labTUV) data for Utah FORGE well 16A(78)-32, containing raw waveform data, summary data and charts for each of the 3 zone tests. https://gdr.openei.org/files/1438/labTUV.zip
57 Deformation Rate Analysis (DRA) data for Utah FORGE well 16A(78)-32 organized by zone, each containing a data sheet describing specimen dimensions and loading sequence, INSTRON data giving load vs time, data used to compute axial displacement, and charts generated from the data. https://gdr.openei.org/files/1438/DRA.zip
10 README document describing the organization of the Triaxial Ultrasonic Velocity (labTUV) and Deformation Rate Analysis (DRA) data and providing additional information and context. https://gdr.openei.org/files/1438/README%20DRA%20and%20TUV%20Data%20for%20Well%2016A78-32.docx

Tags

  • weight-of-evidence
  • field-measurement
  • geophysics
  • tuv
  • modeling
  • forge
  • egs
  • utah-forge
  • laboratory
  • stress-test
  • triaxial-ultrasonic-velocity
  • 16a78-32
  • well-data
  • characterization
  • deformation-rate-analysis
  • woe
  • dra
  • in-situ-stress
  • geothermal
  • energy

Topics

Categories