珠江口盆地靖海凹陷多边形断层系统成因及油气成藏意义

发布时间：2018-02-08 13:50

本文关键词： 多边形断层油气运移油气成藏靖海凹陷珠江口盆地　出处：《石油与天然气地质》2017年02期 　论文类型：期刊论文

【摘要】：珠江口盆地靖海凹陷中新统发育大量密集分布、走向多变、延伸长度有限、断距小、倾角陡且互相切割及平面上呈多边形几何特征的小型正断层。综合研究认为,该系列小断层为非构造成因的多边形断层。多边形断层是由于地层超压诱导的周期性压力释放而形成的微裂缝,超压成因以快速沉积造成的不均衡压实为主,带动水热增压作用和矿物脱水作用。靖海凹陷由始新世—渐新世裂谷断陷期,过渡为早中新世—中中新世的裂后热沉降期,沉积由近海浅湖相过渡为深海-半深海相,沟通断陷期陆相及浅海相烃源岩和坳陷期深海-半深海相储集层的长期断裂不发育,缺乏油气垂向运移的主要通道,成为制约该期成藏的关键因素。多边形断层在靖海凹陷中新统珠江组和韩江组中广泛发育,可作为油气运移的输导通道,起到对油气运移分流调节作用,控制成藏区带分布,对靖海凹陷裂后热沉降期油气成藏具有重要的意义。
[Abstract]:The Miocene in Jinghai sag, Pearl River mouth basin, developed a large number of small normal faults with dense distribution, changeable strike, limited extension length, small fault spacing, steep dip angle and cutting to each other, as well as polygonal geometric features on the plane. The series of small faults are polygonal faults of non-tectonic origin. Polygonal faults are micro-fractures formed by periodic pressure release induced by formation overpressure, and the causes of overpressure are mainly uneven compaction caused by rapid deposition. Jinghai sag changed from Eocene to Oligocene rift fault depression to early Miocene Miocene post-rift thermal subsidence period, and the sediment transition from offshore shallow lacustrine facies to deep-sea semi-deep sea facies, which led to hydrothermal pressurization and mineral dehydration, and changed from Eocene to Oligocene rift fault to early Miocene to Miocene post-rift thermal subsidence. The long-term faults of the continental and shallow marine source rocks and the deep-sea and semi-deep sea facies reservoirs in the depression period are not developed, and the main channels for the vertical migration of oil and gas are lacking. Polygon fault is widely developed in Miocene Zhujiang formation and Hanjiang formation in Jinghai sag, which can be used as a migration channel for oil and gas migration, which can regulate the distribution of hydrocarbon migration and control the distribution of Tibetan zone. It is of great significance for oil and gas accumulation during the thermal subsidence period in Jinghai depression.
【作者单位】：中海石油(中国)有限公司深圳分公司;
【基金】：国家科技重大专项(2008ZX05025-006-03)
【分类号】：P618.13

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