渤海湾盆地缓坡带类型及其油气分布特征

Ramp zone types and their hydrocarbon distribution characteristics in the Bohai Bay Basin

赵珊 刘华 蒋有录 王永诗 郝雪峰 张聪

Zhao Shan Liu Hua Jiang Youlu Wang Yongshi Hao Xuefeng Zhang Cong

含油气盆地缓坡带是油气聚集的有利指向区，明确各类缓坡带油气分布样式对于指导油气勘探具有重要意义。以渤海湾盆地为例，基于构造分区影响下的缓坡带基底产状，将缓坡带划分为简单型缓坡带、过渡型缓坡带和复杂型缓坡带3种类型。研究表明，简单型缓坡带构造活动弱，基底形态呈单斜式，倾角小，油气藏类型以构造-岩性、岩性油气藏为主，油气富集层系单一，以早期成藏为主，具有典型的“一字型”油气分布特征；过渡型缓坡带构造活动较强，基底呈双斜式，油气藏类型以构造、构造-岩性为主，存在少量地层油气藏，富集层系跨度较大，油气借助于断层和砂体配置运移，具有“阶梯型”油气分布特征；复杂型缓坡带构造活动强，基底形态呈三斜式，油气藏类型以构造、岩性-构造为主，且地层油气藏数量相对较多，油气富集层位跨度大，具有“梳齿型”油气分布特征。

The ramp zone of the petroliferous basin is a favorable area for hydrocarbon accumulation.To identify the distribution of oil and gas in the ramp zones of various kinds is of great significance for oil and gas exploration.Taking the Bohai Bay Basin as an example,we divided its ramps into three types,namely the simple type,transitional type and complex type,based on the basement geometry of the ramps under the impact of tectonic zonation.The simple type of ramp zone is characterized by weak tectonic activity and one-way dipping basement geometry with a small dip; structural-litho-logic and lithologic reservoirs are dominant in this type,and its hydrocarbon enrichment concentrates in one single layer and most hydrocarbons accumulate in early periods with a typical "line-styled" hydrocarbon distribution.The transitional type features stronger tectonic movement and the two-way dipping basement geometry,and the structural and structural-lithologic reservoirs are dominant in this type,with a small number of stratigraphic reservoirs.Hydrocarbons enrich in multiple layers through migration along faults and sand body,resulting in a ladder-shaped reservoir distribution.While the complex ramp zone features strong tectonic activity and three-way dipping basement geometry.The structural and structu-ral-lithologic reservoirs are dominant,with a large number of stratigraphic reservoirs.The hydrocarbons enrich in multiple layers,leading to a "comb-shaped" reservoir distribution.

10.11743/ogg20190202