Thermally-Induced Breakouts: Insights from True-Triaxial Tests with Acoustic Emission Monitoring
Borehole breakouts are used to constrain the magnitude of maximum horizontal stress. However, when the borehole wall strength is higher than the in situ tangential stress, borehole wall failure does not develop. Additional compressive stress can be induced by heating borehole walls. To validate this concept experimentally, we conducted room-temperature and elevated temperature true-triaxial tests on Berea sandstone and Niagaran dolomite samples. We used acoustic emission sensors to capture the onset of breakout development, and we measured the temperature close to borehole wall to assess the magnitude of induced thermal hoop stress. The test results show that within a specific rock type, the breakouts develop in similar manner in room-temperature and elevated-temperature tests. Therefore, the maximum horizontal stress can be constrained from the following dataset: critical tangential stress at which breakout develops, minimum horizontal stress, elastic and thermal properties, and temperature change at the borehole wall.
- Research Organization:
- RESPEC Company LLC
- Sponsoring Organization:
- USDOE Office of Fossil Energy (FE)
- DOE Contract Number:
- FE0031688
- OSTI ID:
- 1838026
- Resource Relation:
- Conference: 54th U.S. Rock Mechanics/Geomechanics Symposium, physical event cancelled
- Country of Publication:
- United States
- Language:
- English
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