贵州遵义地区安场向斜“四层楼”页岩油气成藏模式研究

Peservoir-forming pattern of “four-storey” hydrocarbon accumulation in Anchang syncline of northern Guizhou Province

中国南方地区从震旦纪到古近纪发育多套烃源岩,由于经历多期构造运动,油气保存条件欠佳。60多年来,除四川、江汉、苏北等盆地外,盆外复杂构造区油气调查始终未获重大发现。文章通过对野外地质调查、地球物理勘查和系统的油气成藏条件研究,认为黔北安场向斜五峰—龙马溪组富有机质页岩发育、热演化程度适中,石牛栏组储集性能较好,向斜翼部逆断层封挡,具备良好的页岩气、油气富集成藏条件。在向斜西翼部署实施的安页1井,在栖霞组、石牛栏组、五峰—龙马溪组和宝塔组获得"四层楼"式油气显示。其中,石牛栏组获得日产超过10×104m3高产工业气流,开辟了南方油气勘查的新区、新层系和新类型。安页1井的突破,证实了黔北—渝东南盆外复杂构造区具有常规、非常规油气同生共存的成藏条件,对邻区广泛发育的残留向斜油气勘探具有重要的指导意义。

The Sinian-Paleogene period in South China developed several sets of hydrocarbon source rocks.Because of the multistage tectonic movements,the preservation conditions of oil and gas are poor.Over the past60years,oil and gas survey in complex structure areas outside the basins has not made a major breakthrough except for Sichuan,Jianghan and Subei basins.Based on field geological survey,geophysical exploration and researches on hydrocarbon accumulation conditions,the authors hold that,because the Wufeng-Longmaxi Formation has well-developed organic matter-rich shale,moderate thermal evolution,Shiniulan Formation provides good reservoir,and syncline wing is blocked by reverse faults,the shale gas,oil and gas accumulation conditions are very favorable.Well Anye-1made the"four-storey"type oil and gas breakthrough in the Shiniulan Formation,Wufeng-Longmaxi Formation,Baota Formation and Qixia Formation.In the Shiniulan Formation,more than10×104m3industrial gas is produced everyday.New areas,new layers and new types are therefore opened up for oil and gas exploration in South China.The breakthrough of well Anye-1confirms the fact that there exist the reservoir-forming conditions for the coexistence of conventional and unconventional oil and gas in the complex structure areas outside the basins in northern Guizhou and southeastern Chongqing.These achievements are of great significance for the development of residual syncline oil and gas exploration in the adjacent areas.