Simulation and analysis of embedding modes and processes for differential pressure power generation in gas storage reservoirs

Objective This paper aims to explore and facilitate the large-scale application of natural gas differential pressure power generation technology in gas storage reservoirs, facilitating the transition to a low-carbon development model for gas storage reservoirs, it also addresses the current gap in China regarding the feasibility analysis of embedding differential pressure generator sets into gas storage reservoirs.

Method This paper focused on the natural gas reservoir differential pressure power generation injection and extraction process, analyzed the embedding modes of differential pressure power generation in the reservoirs, established the simulation models of differential pressure power generation processes under five embedding modes such as single unit in the injection and extraction station, double units in the injection and extraction station, wellhead, wellsite, and co-generation. At the same time, the simulation analyzed the influencing factors of the natural gas differential pressure power generation, the pressure reduction operation mode, the diversion operation mode, the results of the operation of the differential pressure power generation, and the parameter changes under different embedding modes.

Result For the single-unit embedding mode of the injection and extraction station, in order to ensure the safe operation of the unit, diversion operation could be used to control the intake flow rate, or the intake pressure could be controlled by the pressure-reducing operation method; the double-unit embedding mode could completely recover the pressure energy of the injection and extraction station; and the wellsite embedding mode could only reduce the power generation rate by 251.88 kW, about 3.4%, compared with the wellhead embedding mode.

Conclusion This study is conducive to understanding the impact of embedding modes on the low-carbon operation of the gas storage reservoirs, clarifying the advantages and disadvantages of different embedding modes, balancing the carbon emissions from the operation of the gas storage reservoirs embedded in differential pressure power generation with the number of units embedded in the system, and providing guidance for the planning and construction of the project of embedding differential pressure generating units in the gas storage reservoirs.