断陷盆地洼陷带岩性油气藏成藏机理及运聚模式

对东营凹陷牛庄洼陷沙三段砂岩透镜体油藏的成藏过程进行了分析,研究了岩性油气藏的成藏机理。结果表明,砂岩透镜体油藏多数为它源性多期幕式成藏,其成藏机理可概括为隐蔽输导和幕式置换。油气通过隐蔽输导体系由源岩向砂体运聚,砂体中地层水与早期充注的油气又通过隐蔽输导体系向外排出,油源断层将众多岩性油气藏中的油气水幕式汇聚到中浅层大中型构造圈闭中,形成早期油气聚集在盆地外部、晚期油气聚集在盆地内部的环状分布。洼陷带岩性圈闭是含油气盆地油气运聚成藏过程中的小型油气集输站。

Reservoir-forming mechanism and migration-accumulation mode of lithological pool in deep sub-depression of rift-subsidence basin

The pools of sand lens in the third section of Shahejie Formation in Niuzhuang sub-depression were analyzed. The results showed that reservoir-forming mechanism of lithological pools included subtle passage and episodic replacement. Oil and gas migrated from source rock to sands, and formation water and the early filled hydrocarbon blew out of sands by subtle passage system. The hydrocarbon of numerous litholocgical pools was episodically gathered in faults, and large and medium size tectonic pools were formed in mid-shallow layers. Oil and gas was annularly distributed outside the basin in the early stage and inside the basin in the late stage. The lithological traps were the minimum oil gas gathering and transferring stations in the course of hydrocarbon migration and accumulation.