A Method for Predicting Gas Injection Ability of UGS Rebuilt from a Sandstone Reservoir
砂岩油藏改建地下储气库注气能力预测方法

The research on the selection and geologic evaluation of sandstone reservoirs to rebuild UGS in the late period of waterflooding is just beginning in China, and it needs further and deep research. On the basis of the technology of foreign aquifer UGS, this paper proposes a mathematical expression to describe the constant speed macroscopic gas injection ability of a sandstone reservoir in the late waterflooding period. Through the expression, the paper further establishes a series of relational graphs between macroscopic gas injection ability and buried depth, permeability and injection gas boosted coefficient. The examples calculation indicates that, under the same other geological and technological parameters, it can both guarantee the high gas injection ability and save the investment cost to choose the moderate buried depth reservoir to rebuild UGS; simultaneously, because of the remarkable difference of fluid mobility radios, it will be more advantageous to make use of the high permeability and the small degree anisotropic reservoir to rebuild UGS.