Fault hazard assessment in shale gas region based on seismicity and stress

Abstract

High-pressure hydraulic fracturing and fluid injection greatly improve the production of dense shale gas and present new challenges worldwide. Hazard assessment is important for a wide range of scientific and industrial processes, particularly in oil and gas simulation and production. In this study, we report the geometric characteristics of faults in a shale gas region and perform plane and surface fitting using singular value decomposition and Gaussian process regression, respectively. The critical pore pressure and equivalent density of the critical pore pressure for fault slip were calculated using Coulomb's law, and the influence of parameter uncertainty was evaluated. Based on the relationship between the seismic event and fault, a list of the top 10 faults with seismicity was presented. Finally, geometric data, equivalent density, seismic events, and fault relationships were integrated. Comprehensive fault hazards were evaluated using the principal component analysis method. The results revealed that the fault area in the southeast was large and the depth reached the basement. Most faults tended NE, which was in the direction of easy failure and fault slip. The F92 fault has several seismic events and releases the most energy, ranking first in the top 10 hazardous fault list. These results potentially contribute to determining shale gas well location and trajectory design and reducing seismic hazards. This study enhances our understanding of fault hazard assessments.