Evaluation on Reserve Producibility in Deep Carbonate Gas Reservoirs with Strong Heterogeneity

Abstract

For sake of figuring out the reserve producibility of different reservoir types in deep carbonate gas reservoirs, three reservoir types in Dengying Formation in Anyue gasfield were taken as objectives to quantitatively represent the producibility via physical simulation experiments, numerical simulation, and field production layer subsection tests. Results show that (1) the experiments on physical simulation reflect the recovery degree of 76.2%, 52.5%, and 24.3% individually in the fractured-vuggy, vuggy, and porous reservoirs; (2) during exploitation, the main productivity contribution is successively from the fractured-vuggy, vuggy, and porous reservoirs; (3) through the developed numerical simulation of mechanism model, the predicted productivity contribution is 49.1% in the fractured-vuggy reservoir, 44.8% in the vuggy reservoir, and 5.5% in the porous reservoir, corresponding to the productivity contribution per unit thickness of 5.0%/m, 2.5%/m, and 0.5%/m, respectively; and (4) based on the field production layer subsection tests, the productivity contribution in the fractured-vuggy, vuggy, and porous reservoirs is respectively 54.8%, 29.8%, and 15.4%, corresponding to the productivity contribution per unit thickness of 5.7%/m, 1.8%/m, 0.9%/m. The research results evaluate that the reserves of fractured-vuggy and vuggy reservoirs have preferable producibility, which provides technical support for the benefit development of the Dengying Formation gas reservoir and can provide reference for the study of reserves producibility of similar gas reservoirs.