This paper investigates the feasibility of a proposed underground gas storage facility. Based on S gas storage, a large-scale 2D hydromechanical coupling FEA model is established to explore the geo-mechanical properties of S gas storage under a multi-cycle alternating injection and production and validated by the interference logging test. To account for the damage development of fault damage area under the influence of seepage-stress coupling, the soil adopts the Mohr–Coulomb constitutive assumption. Additionally, a zero-thickness cohesive element is proposed as a mechanical model to simulate the fault gouge. The mechanical parameters of zero-thickness cohesive elements are verified by a ring shear test and a preliminary FE model. Thereafter, another refined conceptual finite element (FE) model considering the fault damage area, fault core, water-containing damaged area, overburden damaged area, and the contact model between different damaged areas of the fault and the fault core is developed and validated. The simulation results demonstrate that the initial seal ability of the caprock and faults remains intact. Specifically, (i) the maximum caprock and ground displacements are 8.5 cm and 5.4 cm, respectively. (ii) The most significant slip distance is 0.125 mm, indicating that, leakage under the action of multi-period alternating injection–production, the S aquifer structure had no fault activation and caprock. (iii) The risk of fault activation is higher for high-angle faults compared to low-angle faults. Low-angle faults are more susceptible to shear slip. Providing a scientific reference for the feasibility study of gas storage.

本文研究了拟建地下储气设施的可行性。基于S储气库，建立大型二维水力耦合有限元模型，探讨多周期交替注采下S储气库地质力学特性，并通过干涉测井试验进行验证。为了考虑渗流-应力耦合影响下断层损伤区的损伤发展，土体采用莫尔-库仑本构假设。此外，还提出了零厚度粘性单元作为模拟断层泥的力学模型。通过环剪试验和初步有限元模型验证了零厚度粘性单元的力学参数。此后，开发并验证了另一个考虑断层损伤区域、断层核心、含水损伤区域、覆盖层损伤区域以及断层不同损伤区域与断层核心之间的接触模型的细化概念有限元（FE）模型。模拟结果表明盖层和断层的初始封闭能力保持完整。具体来说，(i) 最大盖层和地面位移分别为 8.5 厘米和 5.4 厘米。(ii) 最显着的滑移距离为0.125 mm，表明在多期交替注采作用下渗漏，S含水层结构不存在断层活化和盖层。(iii) 与低角度断层相比，高角度断层的断层激活风险更高。小角度断层更容易受到剪切滑移的影响。为储气库可行性研究提供科学参考。