摘要
珠江口盆地深水区7个凹陷分布于盆地两大一级构造单元珠二坳陷和珠四坳陷内,两大坳陷共同经历了初始裂陷、持续裂陷、裂后沉降早期、裂后沉降晚期和新构造运动五大构造演化阶段。不同构造演化阶段之间以及同一构造演化阶段之内,两大坳陷的构造特征和沉积充填差异明显,进而导致具有不同的油气地质条件与勘探潜力。珠二坳陷发育湖相泥岩、煤系、陆源海相泥岩3类烃源岩;珠四坳陷发育煤系和陆源海相泥岩两类烃源岩,生烃条件逊于珠二坳陷。珠江口盆地深水区在持续裂陷、裂后沉降早期、裂后沉降晚期3个构造演化阶段主要发育多期三角洲砂体和水道—深水扇砂体,珠二坳陷砂体类型多,分布广,储集能力更好。珠二坳陷与珠四坳陷主要发育裂后沉降期成藏组合与持续裂陷期成藏组合,对比两套成藏组合成藏要素,珠二坳陷勘探潜力优于珠四坳陷。
Seven sags in the deep water area of the Pearl River Mouth Basin reside in two first-order structural units, i.e. Zhu II depression and Zhu IV depression. The two depressions commonly underwent five tectonic evolution stages, including initial rifting, sustained tiffing, early post-fiRing subsidence, late post-rifting subsidence, and neotectonic movement. They are significantly different in tectonic characteristics and sedimentary filling in different stages or during file same stage, thereby leading to different hydrocarbon geological conditions and exploration potentials. Three types of source rocks （i.e. lacustrine mudstone, coal-measure and terrigenous marine mudstone） are mainly developed in the Zhu II depression. Two types of source rocks （i.e. coal-measure and terrigenous marine mudstone） are mainly developed in the Zhu IV depression, revealing hydrocarbon accumulation conditions inferior to the Zhu II depression. During the first three stages （i.e. initial rifling, sustained rifting, early post-rifting subsidence, and late post-rifting subsidence）, multi-stage delta and channel-deep water fan sand bodies were developed; the sand bodies in the Zhu II depression are diverse and wide, showing better accumulation capacity. Two sets of plays of late post- rifting subsidence and sustained tiffing are developed in both depressions. By comparing the play elements, it is concluded that the exploration potential of the Zhu II depression is better than that of the Zhu IV depression.
出处
《中国石油勘探》
CAS
北大核心
2017年第6期59-68,共10页
China Petroleum Exploration
基金
国家科技重大专项"海洋深水区油气勘探关键技术"(2016ZX05026007)
关键词
珠二坳陷
珠四坳陷
构造演化
烃源岩
储层
成藏组合
Zhu II depression, Zhu 1V depression, structural evolution, resource rock, reservoir, play
