The stimulated reservoir volume (SRV) exists near hydraulic fractures in gas reservoirs after hydraulically fracturing stimulation, which creates one region with distinct gas reservoir properties from initial formation. Due to strong anisotropy, compared with radial flow model, the elliptical flow model is important for the optimal exploitation of triple media gas reservoirs (TMGR) consisting of matrix, vugs and fractures. The paper presents a composite elliptical flow model to analyse the fractured vertical well transient pressure and rate performance in TMGR with SRV. The inter-porosity flow from matrix to fractures is transient flow. Modified Mathieu functions is employed to solve the mathematical model. There are nine flow regimes based on dimensionless pseudo-pressure curves' characteristics and the comparison of transient inter-porosity flow with steady inter-porosity flow is illustrated. Sensitivity analysis for relevant parameters are conducted, such as well radius, SRV radius, mobility ratio, storativity ratio and inter-porosity flow coefficient.