关键词: 油气藏形成, 油气藏类型, 地层油气藏, 东濮凹陷, 背斜油气藏, 中央隆起带, 构造油气藏, 下第三系, 砂岩体, 古潜山

Abstract: Dongpu depression which is rich in oil and gas is a typical salt-lake basin,is made up of well-developed structures and reservoirs,numerous traps and sandbodies,highly-matured source rocks,good conditions for hydrocarbon escape from source rocks,short distance of hydrocarbon migration and existence of secondary porosity in deeply-buried zones are the basis of the formation of oil and gas pools.Oil and gas pools may be divided into structural and stratigraphic types.The former include anticline pools,which may be further classified as contemporaneous faulted-reverse dragged anticline compressively-faulted anticline,arched-anticline formed by the flow of salt and anhydrife and drapped-structure related to buried hills and differential compaction and drape pools.Stratigraphic-type oil and gas pools may be subdivided into primary sandbody lithological pools and stratigraphic unconformity pools.The central uplift zone in the depression,which is an assemblage of a number of substructures and has a variety of traps especially those with characteristics related to salt structures and salt facies changes,is a large composite oil and gas accumulation belt.Proporly combined with sandbodies,the uplift zone involves multiple oil and gas pools dominated by fault block;Wu Zhuangji oil pools which contains a large amount of oil and gas reserves,located at the western slope of the depression,has been discovered.Reverse dragged structural oil and gas pools,stratigraphic-type oil and gas pools and depply-buried natural gas pools are discovered also in the deeply subsided region and steep slope of the depression.