Dynamic characteristics of underground gas storage rebuilt from carbonate gas reservoir with bottom water and the water flooding mechanism of its well

Injection-production gas capacity, storage capacity and working gas volume are important indexes for measuring the capacity of underground gas storage (UGS). Dynamic characteristics analysis is an important means to evaluate the capacity of UGS. Based on the multi-cycle injection-production performance of a certain UGS rebuilt from the carbonate sour gas reservoir with bottom water, the injection-production capacity of horizontal well was evaluated by analyzing the dynamic characteristics of UGS during its operation. Then, the storage capacity of UGS was checked by using two methods. Finally, the change of the mass concentration of H₂S in the gas reservoir was analyzed, and the operation mode of desulfurization was evaluated. It is indicated that this UGS is high in single well productivity, storage capacity implementing degree and efficient development potential, but its operation mode of desulfurization still needs exploring. What's more, the water flooding mechanism of Well AH1 leading to its off production was studied, and the specific technological measures for restoring the production capacity of gas well were put forward and successfully applied on site. The research results play an important role in guiding the production, operation and gas storage capacity evaluation of UGSs rebuilt from carbonate gas reservoirs with bottom water in China.