Abstract: In view of the special geological conditions of the Shengping gas storage that was reconstructed from a volcanic gas reservoir with bottom water, the effective gas-bearing pore volume was calculated by the gas saturation respectively of pure gas zone, transition zone and water flooded zone, a three-zone storage capacity parameter model of gas storage was established under consideration of effect of water invasion, stress sensitivity, rock and bound water deformation, a calculation method was optimized and designed to iteratively calculate the maximum working gas volume and the relevant storage capacity in different operating pressure intervals, and a quantitative evaluation was conducted on the effect of water invasion, stress sensitivity, rock and bound water deformation and other factors on the storage capacity and working gas volume. The results showed that the loss of gas-bearing pore volume was the largest in the transition zone, followed by the pure gas zone and then the water flooded zone; in terms of the loss of gas-bearing pore volume by different factors, water invasion was the dominant controlling factor, and rock and bound water expansion and stress sensitivity were non-dominant controlling factor and resulted in less loss of gas-bearing pore volume. With the established storage capacity parameter model, the maximum working gas volume was 25.61×10⁸m³ under the upper operating pressure limit of 32 MPa, and the storage capacity is 64.74×10⁸m³ corresponding to the optimal lower operation pressure limit of 18 MPa. The study results can provide reference for the reconstruction of gas storage in similar volcanic gas reservoirs with low permeability and bottom water at home and abroad.

Key words: Shengping gas storage, working gas volume, operating formation pressure, volcanic gas reservoir