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The effect of temperature on injection-induced shear slip of laboratory faults in sandstone.

Authors :
Shen, Nao
Wang, Lei
Li, Xiaochun
Source :
Acta Geotechnica. Sep2024, Vol. 19 Issue 9, p5799-5817. 19p.
Publication Year :
2024

Abstract

Fluid injection into subsurface reservoirs may cause existing faults/fractures to slip seismically. To study the effect of temperature on injection-induced fault slip, at a constant confining pressure of 10 MPa, we performed a series of injection-induced shear slip experiments on critically stressed sandstone samples containing saw-cut fractures (laboratory-simulated faults) under varying fluid pressurization rates (0.1 and 0.5 MPa/min, respectively) and temperatures (25, 80, and 140 °C, respectively). At 25 °C, slow fault slip events with a peak slip velocity of about 0.13 μm/s were observed on a tested sample in response to a low fluid pressurization rate of 0.1 MPa/min. In contrast, fluid injection with a high pressurization rate of 0.5 MPa/min caused fault slip events with a peak slip rate up to about 0.38 μm/s. In response to a given fluid pressurization rate, several episodes of slip events with a higher slip velocity were induced at an elevated temperature of 140 °C, indicating an appreciable weakening effect at elevated temperatures. We also experimentally constrained the rate-and-state frictional (RSF) parameters at varying effective normal stresses and temperatures by performing velocity-stepping tests. The obtained RSF parameters demonstrate that for a relatively high normal stress, increasing temperature tends to destabilize fault slip. Post-mortem microstructural observations reveal that elevated temperatures promote the generation of abundant fine-grained gouge particles associated with injection-induced shear slip. Our experiments highlight that injection-induced fault slip is affected by temperature-related wear production over the fault surface. [ABSTRACT FROM AUTHOR]

Details

Language :
English
ISSN :
18611125
Volume :
19
Issue :
9
Database :
Academic Search Index
Journal :
Acta Geotechnica
Publication Type :
Academic Journal
Accession number :
179635783
Full Text :
https://doi.org/10.1007/s11440-024-02329-5