Analysis of efficient operation conditions of the Shuang 6 gas storage in Shuangtaizi Oilfield, LiaoHe Basin, China

Production safety at the Shuang 6 gas storage facility is controlled by the fault block system underlying the facility. In this study, the “fault valve” theory, Coulomb fracture criterion, and current crustal stress conditions are considered as constraints for the Mohr’s circle stress calculation model, which is used to simulate and evaluate the fault stability beneath the facility. The stability margin of faults at the current maximum operating storage pressure and the formation fluid pressure (activation pressure) corresponding to fault activation are estimated, providing a basis for the upper limit of gas injection pressure for gas storage safety. The results show that the related internal faults at Shuang 6 gas storage are in a stable state under the current crustal stress and the highest gas storage pressure. The fault activation pressures of the Xing II and Xing III formations in the Shuangtaizi area exceed 8 MPa higher than the original formation pressures, and there is a large space available for additional gas storage capacity, including other regional storage groups.