The increased seismicity in Oklahoma is associated with the reawakening of the ancient basement faults due to wastewater disposal into the Arbuckle group. Since the shallow pore pressure information obtained from direct borehole measurements in Arbuckle group cannot represent the deep pore pressure distribution at the basement faults, in this study we estimate the pore pressure distribution around the basement faults using well constrained focal mechanisms. Assuming Coulomb faulting theory and welldefined tectonic stress field, we mapped the spatiotemporal pore pressure distribution from March 2013 to March 2016. From the results, overall the pore pressure perturbations around the basement faults are below 0.5 MPa. The estimation errors are generally below 0.2 MPa. Analyzing the temporal evolutions, we find that the spatial occurrence and quantity evolutions of seismicity are well correlated with the estimated temporal pore pressure perturbations. This approach could be used to assess the spatial occurrence of future seismicity.
Presentation Date: Wednesday, October 17, 2018
Start Time: 1:50:00 PM
Location: 208A (Anaheim Convention Center)
Presentation Type: Oral