东海陆架盆地瓯江凹陷油气成藏机制探讨  

Mechanism of Hydrocarbon Accumulation in Oujiang Sag,the East China Sea Shelf Basin

作　　者：郝乐伟[1] 王琪[1] 梁建设 唐俊[3] 廖朋[1,4] 

机构地区：[1]中国科学院油气资源研究重点实验室,甘肃兰州730000 [2]中海石油研究总院,北京100027 [3]内蒙古科技大学数理与生物工程学院,内蒙古包头014010 [4]中国科学院大学,北京100049

出　　处：《天然气地球科学》2014年第6期848-859,共12页Natural Gas Geoscience

基　　金：中国科学院西部行动计划项目(编号:KZCX2-XB3-12);中国科学院油气资源研究重点实验室开放基金(编号:KFJJ2013-01)联合资助

摘　　要：利用地震、测井及地球化学资料,结合盆地模拟技术,对瓯江凹陷构造演化、古地温及超压演化进行了系统研究,结果表明:瓯江凹陷经历了断陷、拗陷和区域沉降3个构造演化阶段,构造演化控制了沉积体系的发育与展布,发育了月桂峰组、灵峰组和明月峰组3套烃源岩。研究区古地温场经历了埋藏升温—抬升降温—埋藏升温的演化过程,且西次凹经历的古温度高于东次凹。这种差异性热演化控制了研究区烃源岩的生烃作用,瓯江凹陷西次凹烃源岩成熟度明显高于东次凹。瓯江凹陷发育有异常高压,且经历了增压—泄压—增压的过程,异常高压为油气的运移提供了驱动力。构造演化、热流和生烃作用以及动态超压的积累与释放,三者联合控制了瓯江凹陷的油气成藏,但三者在时间上要相互匹配,相互耦合才能促进油气成藏。Using seismic, logging and geochemical data combined with basin modeling, this paper discussed tectonic evolution,paleotemperature and overpressure evolution in Oujiang Sag. The results show that tectonic evolution stage of the Oujiang Depression experiences a rift, depression and regional deposition, which controls the development and distribution of depositional systems. It deposits three sets of source rocks, Yue Guifeng Formation, Lingfeng Formation and Mingyuefeng Formation,in which the Yueguifeng Formation is the main source rocks. Paleotemperature field of the study area has experienced the evolution of burial warming-uplift cooling-burial warming,and the paleo-temperature of west subsag is higher than the east subsag. Because of this thermal evolution difference, the source rocks maturity in the west subsag is higher than that in the east subsag. Abnormal high pressure experiences a supercharge-decompression-supercharge process in Oujiang Sag. Abnormal high pressure can provide a driving force for oil and gas migration. The abnormal high pressure decompression process occurs in Late Eocene, which is the importance time of oil and gas migration. The coupling of the tectonic evolution,the accumulation of the dynamic pressure and re- lease,heat flow and hydrocarbon controls the formation of oil-gas reservoir in Oujiang Sag.

关 键 词：瓯江凹陷 构造演化 古地温 异常高压 成熟度 成藏 

分 类 号：TE122.3[石油与天然气工程—油气勘探]