Horizontal prediction of the hydrocarbon reservoirs in the Penglaizhen Formation, Xinchang Gas Field, West Sichuan Depression

The Jurassic strata are considered as the important target strata for the exploration and development of the supergene gas in western Sichuan. The sequence stratigraphic framework of the Upper Jurassic Penglaizhen Formation has been constructed in the light of the principles of sequence stratigraphy. The results of research show that the favourable reservoir sandstones occur primarily in the later stages of base-level falls and the early stages of base-level rises. The sedimentary facies and microfacies may be identified for the hydrocarbon reservoirs on the basis of well logs, depositional and seismic indicators, and the horizontal prediction of the favourable hydrocarbon reservoirs may be effectively made on the basis of several criteria especially seismic ones for the recognition of gas-bearing sandstones.