Evaluation of fault slip probability of geothermal large-scale development: A case study of deep karst geothermal reservoir in Xiong'an New Area

Xiongan New Area is rich in geothermal resources and has broad prospects for large-scale development and utilization, which is of great significance to the realization of "green Xiongan". Many scholars have focused their research on geological structure exploration, resource evaluation, crustal stability, etc. However, the study on the possible fault sliding caused by the large-scale development of deep karst thermal storage is weak. On the basis of geomechanical theory and geothermal geological survey, Monte Carlo stochastic simulation method was used to evaluate the characteristics of main faults (strike, dip, slip friction coefficient, etc.) and geostress distribution (pore pressure, maximum/minimum/vertical principal stress magnitude and direction, etc.) in Xiongan New area for quantifying the activation possibility of natural faults under large-scale development and utilization. The results show that the maximum slip trends of proven faults under natural, large-scale recharge and hydraulic fracturing conditions are 0.26, 0.27 and 0.40, respectively. Geothermal development will not cause fault activation. The study establishes confidence in geothermal development and provides support for safe geothermal use in Xiong'an New Area.