珠江口盆地文昌A凹陷中南部油气成藏新认识与勘探启示

New understanding and exploration enlightenment of oil and gas accumulation in the central and southern part of Wenchang A sag in the Pearl River Estuary Basin

文昌9-7的发现打破了文昌A凹陷近10余年来勘探低谷,但是各构造带油气差异富集规律认识不清制约了勘探持续突破。本文通过剖析各构造带成藏关键问题,探讨油、气富集的主控因素,并提出文昌A凹陷生烃潜力大幅提升;帚状断裂北东段控制六号断裂带珠海组砂体优势展布;珠三南断裂带北部北东、东西向断层交汇处油气垂向运移活跃;南断裂带中、南部恩平组具有三凹供烃优势、油气主要纵向近源富集于恩平组;穿断运移规模是断阶带成藏关键等成藏新认识。在此基础上指出了各构造带下一步有利勘探区带。

The discovery of Wenchang 9-7 has broken the exploration trough of Wenchang A sag in the past 10 years,but the unclear understanding of the oil and gas difference enrichment law in each structural belt restricts the continuous breakthrough of exploration.In this paper,the key problems of reservoir formation in each tectonic zone are analyzed,the main controlling factors of oil and gas enrichment are discussed,and it is proposed that the hydrocarbon generation potential of Wenchang A sag is greatly improved.The north-east section of the broom fault controls the dominance of the sand body of the Zhuhai Formation in the No.6 fault zone;The vertical migration of oil and gas is active at the intersection of north-east,east-west and east-west faults in the north of the Zhusanan fault zone.The central and southern Enping Formations of the southern fault zone have the advantage of three-concave hydrocarbon supply,and the main longitudinal proximate sources of oil and gas are enriched in the Enping Formation.The scale of transcendent migration is the key to the formation of faulty bands.On this basis,the next favorable exploration zone of each tectonic zone is pointed out.