Seepage Laws and an Effective Development Mode for the Intraplatform Dengying 4 Gas Reservoirs, Anyue Gasfield, Sichuan Basin

In recent years, the intraplatform gas reservoir of the fourth Member of Sinian Dengying Formation(Dengying 4) in Anyue Gas field has become an important field of exploration and development in Sichuan Basin. However, the reservoir in the intraplatform is thin, and the physical property is much lower than that of the platform marginal, and the percolation and productivity characteristics of the gas reservoir are not clear. By selecting cores in the intraplatform and carrying out stress sensitivity experiments, seepage experiments and parallel core depletion experiments, the microscopic percolation and productivity characteristics in the gas reservoir platform are clarified. The comparison with the experimental results at the platform marginal shows that the stress sensitivity of the core in the platform is stronger, in which the stress sensitivity of the fracture-cave core is stronger, and the existence of irreducible water will aggravate the effect; the overall permeability capacity of the core in intraplatform is even worse, especially the porous core, and the output is only 1/68 of that of the core at the platform marginal, which is difficult to be used effectively in the later stage of depletion development. Based on the comparative analysis results of permeability and productivity results, the development in the platform should maintain a small production pressure difference and drill into a longer high-quality reservoir well trajectory in order to realize the effective development of the gas reservoir. The research results have important guiding significance for the scientific development of low permeability-thin carbonate karst gas reservoirs.