Fault Dynamic Stability Evaluation and Application Based on Slip Trend and Expansion Trend

Fault stability evaluation is an important process of geological integrity evaluation of underground gas storages (UGSs), which is the basis of safe and efficient operation of UGSs. In this paper, the M1 UGS in Jidong Oil Field is taken as the research object. Based on the study of faults characteristics, vertical sealing of fault and lateral sealing of fault and so on, the main faults affecting the geological integrity of the reservoir are screened and the rock mechanics parameters are determined. The theory is based on fault reactivity mechanism and rock fracture mechanism, the dynamic stability of faults in UGS is evaluated by fault slip trend and expansion trend. In this study, TrapTester software was used to construct a three-dimensional geological model, and combined with the present in-situ stress characteristics of block M. And specify the probability of reactivity and calculate additional minimum formation pressure of reactivity of major faults developed in the NgII–NgIV of M1 UGS under the condition of current reservoir pressure. It provides reference for the design of UGS operating pressure and storage capacity parameters.