Experimental study on reservoir stress sensitivity of underground storage of depleted gas reservoirs

During the operation of "strong injection and rapid production" and "big huff and puff" in the underground storage of depleted gas reservoirs,the stress sensitivity in the repeated process of reservoir pressure rises and falls is unclear.Combined with the geological and development characteristics of the target underground storage with gas reservoirs,the sensitivity evaluation of rock stress permeability and stress porosity with multi injection-production cycles under the working conditions was carried out through indoor experiments,which provides the basis for the optimization of injection-production parameters and storage capacity evaluation of the underground storage.The experimental results show that the permeability of rock decreases when the internal pressure rises and falls for several times.With the increase of internal pressure,the change range of permeability decreases.The stress sensitivity of permeability,porosity and compressibility is weak.According to the analysis of stress sensitivity,the target depleted gas reservoir is suitable for gas storage site and can operate effectively.