Study on multi-cavern optimization allocation for injection and production of salt cavern gas storage

The salt cave gas underground gas storage is composed of a plurality of independent cavity, which are uniformly monitored and deployed by the system on the ground. The morphological structure, thermal state and supporting wellbore parameters of each cavity are different. Based on the thermal characteristics of the injection and operation of the salt cavern gas storage, the multi-cavity injection and production operation of the gas storage reservoir is regarded as the overall system. Under the constraints of urban peaking demand, reservoir gas injection plan, wellbore erosion flow, and operating limit pressure, the minimum compressor power consumption during the gas injection, the minimum multi-cavity total temperature rise, the power consumption temperature rise double target, and the minimum multi-cavity total pressure drop during gas production are optimized. The model of multi-cavity injection gas production in salt cavern gas storage was established. The model was solved by complex genetic algorithm. The optimal daily injection volume of each cavity was determined, and the results of the production were compared and analyzed. The results show that reasonable optimization of production can effectively improve the economics of gas storage, improve the total storage capacity of the gas storage, avoid excessive pressure drop of individual chambers, and help to maintain the stability of the chamber. Based on the results of gas production and distribution, the control scheme of multi-cavity operation of salt cavern gas storage is proposed. The research results can provide reference for the formulation and production scheduling of salt cavern gas storage.