Utah FORGE Project 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
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
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
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 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

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