Interpretation, Characterization, and Rupture Hazard Assessment of Faults in the Permian Basin

Presenter: Elizabeth Horne

Co-Authors: Peter Hennings, Katie Smye, Amanda Calle, and Alan Morris Bureau of Economic Geology, Jackson School of Geosciences, the University of Texas at Austin.

The Permian Basin of West Texas and Southeast New Mexico is the most productive petroleum province in the world, with over 35,000 horizontal wells drilled in recent years. The region is experiencing elevated levels of seismicity alongside petroleum development, with over 680 earthquakes of ML≥3.0 since 2017 and 11 earthquakes of ML≥4.5 since 2021. Many of these events have been linked to oilfield operations, including wastewater disposal at multiple subsurface levels and, to a lesser degree, hydraulic fracturing. However, linking earthquakes to hazardous faults has been challenging due to limitations of existing fault maps.

Here we present a regional interpretation, characterization, and kinematic synthesis for basement-rooted faults mapped across the Permian Basin to understand the causal factors of earthquakes in the region and assess the evolving hazard. Our fault map includes over 11,000 km (~8,000 mi) of basement-rooted fault length mapped across the Permian Basin. Faults are characterized according to morphology (length, orientation, structural style), as well as mapping confidence (high and moderate) to reflect variability in the quality, density, and aerial extent of data. We also perform fault rupture hazard analysis in the form of fault slip potential (FSP, expressed as the pore-pressure required for fault criticality, Ppcrit), and compare the results with multiple earthquake catalogs to better understand fault sensitivity, determine which faults have been seismogenic, and understand the uncertainties of these assessments.

ELIZABETH HORNE is a Research Scientist Associate III at The University of Texas Bureau of Economic Geology where she is the structural interpretation specialist for the TexNet Seismic Monitoring and Center for Integrated Seismicity Research (CISR) consortium. She is also the lead Principal Investigator for the Regional Induced Seismicity Collaborative (RISC). Elizabeth received a B.S. in Geology at Utah State University in 2013 and a M.S. in Geology at Colorado School of Mines in 2016. Her research interests include integrating field and subsurface datasets to generate three-dimensional models that are used to better understand the kinematic evolution of various structural systems, as well as assess seismic hazards, both naturally occurring and induced. Elizabeth is a member of several professional societies, including: AAPG, AGU, GSA, and RMAG.