渤中21-22构造区断裂演化及其对油气的控制作用

Fracture evolution of Bozhong 21-22 structure area and their control on hydrocarbons

渤中21-22构造区构造活动活跃、断裂系统复杂。利用地震、钻井、地化和试油等资料,研究渤中21-22构造区断裂分布、断裂演化等特征,分析断裂系统对油气成藏条件的控制作用。结果表明:古近纪早期强烈伸展作用控制渤中西南次洼的形成,进而控制烃源岩的分布;在印支晚期、燕山早期、燕山中期和燕山晚期叠加作用控制下,研究区发育构造圈闭、岩性—构造圈闭、岩性—地层型圈闭等类型;印支晚期、燕山早期和燕山晚期等构造运动控制古生界碳酸盐岩储层物性;由断裂、不整合面和砂(砾)岩层等共同组成研究区的疏导体系,其中断裂占主导地位。已钻井揭示研究区为油气有利的优势聚集区,具有较大的勘探潜力。

Bozhong 21-22 structure area experienced strong tectonic activities and formed a complex fracture system.In this paper,fractures distribution,evolution and their control on hydrocarbons were studied based on data of seismic,drilling,geochemistry,oil testing and so on.Research shows that early extensional process controls the formation of southwest Bozhong sag and it then controls distribution of source rocks.Three types of trap including structural trap,lithologic-structural and lithologic-stratigraphic trap developed under the superposition of late Indosinian movement and Yanshan movement.Carbonate reservoirs' physical property is controlled by late Indosinian movement,early and late Yanshan movement.A petroleum migration system was formed with fracture,unconformity surface and sand(gravel)layers,in which fracture plays a core role.It has been revealed by drilling that this area is advantagous accumulation zone for oil and gas and it has great exploration potential.