四川盆地东部大中型气藏成烃条件分析

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

应用含油气系统理论和气藏地球化学方法,研究了四川盆地东部石炭系和下三叠统飞仙关组大中型气藏的烃源地球化学控制因素。指出:川东地区发育的下志留统和上二叠统两套大中型泥质烃源岩是石炭系和下三叠统飞仙关组大中型天然气藏的烃源保障,石炭系和下三叠统飞仙关组大中型气藏的形成受开江印支—燕山期古隆起的控制,喜山运动形成的圈闭对天然气成藏具有调整作用。

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.