ON THE HYDROCARBON GENERATION CONDITIONS OF THE LARGE AND MIDDLE SCALE GAS FIELDS IN EASTERN PART OF SICHUAN BASIN

The hydrocarbon generation conditions of Carboniferous and low Triassic large and middle scale gas fields in eastern part of Sichuan basin have been studied adopting the petroleum system and the gas reservoir geochemical method in this paper. The two suits of dull muddy rocks in Low Silurian and upper Permian is respectively the hydrocarbon source rocks for the Carboniferous and low Triassic gas fields in eastern part of Sichuan basin.Here, the gas concentration is mainly controlled by Kaijiang Paleo-uplift formed in Indosinian-Yanshan periods. The traps formed in Himalaya period may adjust the reservoir forming and control the present distribution of gas fields.