Objective To address the growing gap between China’s rapidly increasing demand for natural gas peak-shaving and the limited effective working gas volume of underground gas storage facilities, this study reviews the development of depleted-reservoir-type gas storage in China. It focuses on challenges such as low reservoir utilization and the multi-factor constraints on capacity expansion and production ramp-up. Key factors— including pore deformation under alternating stress, salt deposition and secondary water locking during “dry injection and wet production”, dynamic expansion of the gas-water transition zone, and multi-field coupling damage—are systematically analyzed. The study aims to reveal the coupling mechanisms between complex geological conditions and high-frequency injection-production operations, providing a theoretical foundation for developing a generalizable technical system to expand capacity and achieve production ramp-up in depleted-reservoir-type gas storage facilities.
Methods Based on construction and operation data from typical gas storage facilities in China, combined with laboratory experiments and engineering practices, a capacity expansion and production ramp-up system centered on “well pattern optimization, injection-production regulation, edge water displacement, and liquid drainage” was proposed. The coupling relationships among these four technical units were analyzed, establishing a technical pathway from geological understanding and well pattern design to injection-production operations and reservoir capacity reutilization.
Results Depleted-reservoir-type gas storage facilities in China are generally constrained by complex geological conditions—such as tectonic fragmentation, deep burial and high pressure, strong reservoir heterogeneity, and extensive edge and bottom water—as well as by multi-cycle injection-production dynamics, including alternating stress damage, salt deposition near the wellbore, secondary water locking, and expansion of the gas-water transition zone. Consequently, the effective utilization rate of reservoir capacity is significantly below design levels, and single engineering measures are insufficient for sustained capacity expansion. By optimizing the injection-production well pattern and implementing differentiated injection-production strategies, reservoir control can be expanded and damage from stress and salt deposition mitigated. Combined with edge and bottom water displacement and liquid drainage measures, these approaches release pore space occupied by water and liquid hydrocarbons, control water invasion risk, improve gas-phase seepage conditions, and enhance both reservoir utilization efficiency and peak-shaving capability.
Conclusion Establishing a coupling control system integrating well pattern, injection-production, water flooding, and liquid drainage is an effective solution for capacity expansion and production ramp-up in depleted-reservoir-type gas storage facilities under complex geological conditions. However, quantitative constraints on gas and water migration in micro-nano pores and the critical conditions for liquid drainage and capacity expansion remain insufficient. In the future, dynamic control technologies leveraging intelligent optimization algorithms and multi-field coupling models can be developed to shift capacity expansion and production ramp-up from experience-driven to model-guided approaches, providing theoretical support and technical guidance for the safe and efficient operation of gas storage facilities in China.
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