Abstract
Based on the previous study of a single medium model, the dual medium model for the fractured composite reservoir and the triple medium model for a fracture−cavity composite reservoir was established, respectively. The similarities and differences in the corresponding pressure dynamic curves of each model were analyzed, and the general model of a composite gas reservoir composed of different inner and outer zones was obtained. The general model can be more easily used in actual production, and the accuracy and practicability of the model were verified by case analysis.