金湖凹陷石港断裂带构造特征及控油作用

Structural characteristics and its control on oil and gas of Shigang fault zone in Jinhu Sag

王新新¹ 戴俊生² 马洪坤¹

中国石油塔里木油田公司勘探开发研究院，新疆 库尔勒 841000 中国石油大学（华东）地球科学与技术学院，山东 青岛 266580

Research Institute of Petroleum Exploration and Development, Tarim Oilfiled Company, PetroChina, Korla 841000, China School of Geosciences, China University of Petroleum, Qingdao 266580, China

利用苏北盆地金湖凹陷的地质及地球物理资料，根据区域构造演化背景，描述了该凹陷石港断裂带的构造特征，研究了其构造演化规律，定量计算了石港断裂带的断层活动性，并探讨了其构造演化阶段。结果表明，金湖凹陷石港断裂带地区主要发育北东走向和近东西走向的2组断层。石港主断裂沿走向呈3段，即北段、中段、南段，北段主要为雁列式断层、负花状构造，南段以帚状断裂、阶梯状断裂为主。石港断裂带的构造演化可分为3个阶段：阜宁期走滑伸展主断层活动阶段、戴南三垛期强伸展走滑负花状构造发育阶段、新近纪第四纪构造稳定阶段。石港断裂带的油气藏主要受构造的控制，一系列次级断层与主干断层形成断鼻构造与复杂断块圈闭；戴南三垛期断层活动性强，有利于聚集来自三河次凹的油气，形成油气藏。结合断层封闭性及裂缝预测结果，认为石港断裂系的东侧断裂夹缝带、石港和桥河口地区是油气的主要富集区。

Based on the interpretation of geological and geophysical data and the background of regional tectonic in Jinhu Sag, Subei Basin, structural features of Shigang fault zone in Jinhu Sag were described, the pattern of tectonic evolution of Shigang fault zone in the sag was researched, the activities of faults were calculated and the stages of tectonic evolution were discussed. The results show that two sets of cross faults with NE strikes and nearly EW strikes developed in Shigang fault zone. The main fault of Shigang is divided into three sections, namely northern, central and southern section. En-echelon faults and negative flower structure developed in northern section while southern section focused on broom faults and stepladder fault structure. The tectonic evolution is divided into three stages: strike-slip main fault activated in Funing period, strong strike-slip negative flower structure developed during Dainan and Sanduo periods, the faults were stable in the Neogene and Quaternary. The oil and gas of Shigang fault zone are controlled by tectonics. A series of secondary faults and main fault formed fault noses structure and complex fault block traps. It was the strong fault activity during Dainan and Sanduo periods that was favorable to accumulate the oil and gas from Sanhe subsag and to form oil/gas reservoir. Combined with the results of fault sealing and fracture predicting, the eastern fault belt of Shigang fault zone, Shigang and Qiaohekou are the main petroleum enriched areas.

10.6056/dkyqt201506002