Study on Sealing Evaluation of A Gas Storage Tank in Liaohe Basin

The evaluation of airtightness is an important task in the construction and operation of gas storage facilities. The A gas storage facility in the Liaohe Basin is a fault controlled edge water gas storage facility. Through a combination of indoor experiments and theoretical analysis, the sealing performance of the A gas storage facility is comprehensively evaluated from both the cap rock and fault perspectives. Research has shown that the mudstone at the top of the third section of the Shahejie Formation is a thick cap rock of the gas storage target layer. This cap rock is distributed and stable throughout the area, with a thickness of 70–220 m. The mudstone is deposited in a stable medium to deep water environment, and the clay mineral composition is mainly composed of Yimeng mixed layer minerals. It is easy to expand when encountering water, and the cap rock has good sealing properties. Based on the comprehensive evaluation of lateral fault sealing, fault stability, fracture stability, and hydraulic fracturing pressure, a comprehensive analysis was conducted on the upper limit pressure of A gas storage facility. The upper limit pressure of the gas storage facility was divided into four risk pressure intervals, and it is recommended to maintain the upper limit pressure within 13.4 MPa to ensure the safe operation of injection and production in A gas storage facility.