The static sealing of underground gas storage (UGS), including the integrity of cap rocks and the stability of faults, is analyzed from a macro perspective using a comprehensive geological evaluation method. Changes in pore structure, permeability, and mechanical strength of cap rocks under cyclic loads may impact the rock sealing integrity during the injection and recovery phases of UGS. In this work, the mechanical deformation and failure tests of rocks, as well as rock damage tests under alternating loads, are conducted to analyze the changes in the strength and permeability of rocks under multiple-cycle intense injection and recovery of UGS. Additionally, this study proposes an evaluation method for the dynamic sealing performance of UGS cap rocks under multi-cycle alternating loads. The findings suggest that the failure strength (70%) can be used as the critical value for rock failure, thus providing theoretical support for determining the upper limit of operating pressure and the number of injection-recovery cycles for the safe operation of a UGS system.

Remarkable achievements have been attained in the digital transformation and intelligent construction of China’s underground gas storage (UGS) facilities, shown as follows. (1)Key technologies, including the hydrocarbon reservoir-wellbore-pipeline network integrated coupling simulation and digital twins, have been developed for the intelligent construction of UGS facilities. (2)An intelligent cloud platform framework for UGS facilities has been established in the mode of data+platform+application. This platform fully utilizes new-type infrastructure like data center (DC), Internet of Things (IoT), and Industrial Internet of Things (IIoT), aiming to meet the demand for the management, research, production, and services of various business segments. (3)The intelligent construction of UGS facilities has led to the R&D of a UGS information management platform, UGS integrated management platform, decision support system using digital twin-based integrated simulation, and a digital platform covering the entire lifecycle of UGS facilities. The future intelligent construction of UGS facilities will focus on the development of new technologies, encompassing digital twin technologies for geological bodies, high-precision modeling, dynamic visual representations, intelligent operation, real-time intelligent risk warning, industrial software localization, and technologies based on the Beidou Navigation Satellite System (BDS) and satellite internet.