埕岛地区下古生界潜山构造特征及控藏作用

Tectonic characteristics and their controlling effect on reservoir formation of buried hill of Lower Paleozoic in Chengdao area

针对埕岛地区潜山复杂的构造及地层特征,在总结前期研究成果的基础上,运用解析构造学的方法,开展了构造特征的研究。指出了构造对断裂发育、圈闭形成、油气运移及成藏的控制作用。前中生界潜山主要经历了印支、燕山及喜山期三期构造运动,形成了三组二级断层控制三排潜山的构造格局,主要发育了伸展、挤压、走滑、负反转四种构造样式。先期挤压后期多次伸展的构造演化过程产生了大量断鼻、断背斜及断块圈闭。构造作用形成的负反转断层、走滑断层与多期不整合面配置形成了良好的油气立体输导体系。进一步明确了断裂对油气分布控制作用,评价了有利含油圈闭。为东部断陷盆地潜山油藏的勘探提供了借鉴实例。

In view of the complex structure and stratigraphic characteristics of the buried hill in Changdao area,on the basis of summarizing the previous research result,the structural characteristics are studied by the analytical tectonics.The effects of the structure on the fault development,trap formation,hydrocarbon migration and reservoir forming are pointed out.The buried hills of the Premesozoic mainly experienced the tectonic movement of the Indosinian,Yanshan and Himalayan period,the tectonic pattern that three rows of buried hills controlled by three groups of secondary level of fault are formed,four tectonic patterns of extension,compression,strike-slip and negative inversion are mainly developed.The structural evolution of the compression in early stage and the multiple extensions in the late stage resulted in a large number of faulted noses,faulted anticlines and faulted block traps.The negative inversion faults,strike-slip faults and multistage planes of unconformity resulted from the tectonic action formed a good three-dimensional oil and gas transportation system.The control effect of faults on oil and gas distribution is further confirmed,the favorable oil-bearing traps are evaluated.It provides a reference for the exploration of buried hill reservoir in the fault basin of eastern China.