Effect of fault architecture and permeability evolution on response to fluid injection

Zhuo Yang, Alissar Yehya, & James R. Rice

Submitted August 14, 2018, SCEC Contribution #8578, 2018 SCEC Annual Meeting Poster #182

Injection-induced seismicity is thought to be due primarily to increase in fluid pore pressure along existing faults and fractures, which reduces their frictional strength. We address the modeling and prediction of the hydro-mechanical response due to fluid injection, mainly as wastewater injection from the oil and gas industry. We consider the full poroelastic effects and also the changes in porosity and permeability of the rock matrix due to changes in local volumetric strains. Our results reveal the importance of using a realistic fault permeability structure, which includes a low permeability fault core and associated anisotropic high permeability damage zones, while considering permeability evolution due to the elastic deformation. Moreover, we apply our poroelastic model, with spatially and temporally varying permeability, to the Arkansas Guy-Greenbrier wastewater injection case. The overall trend of the Guy-Greenbrier earthquake sequence is consistent with our assumption of an anisotropic permeability structure of fault damage zones, such that they can act as barriers to flow across faults, and as conduits to diffuse pore pressure changes to deeper levels and greater distances. (supported by NSF-EAR 91315447 and NSF-DMR 90820484)

Citation
Yang, Z., Yehya, A., & Rice, J. R. (2018, 08). Effect of fault architecture and permeability evolution on response to fluid injection. Poster Presentation at 2018 SCEC Annual Meeting.


Related Projects & Working Groups
Fault and Rupture Mechanics (FARM)