绥中36-1油田东二下段沉积演化及对油气的控制作用

Sedimentary evolution and its control action on hydrocarbon in lower Ed_2 formation in Suizhong 36-1 oilfield,Bohai Sea

根据岩心相、测井相、地震相,结合对背景资料的分析,认为渤海绥中36-1油田由三角洲、浊积扇、浅湖-半深湖3种沉积体系构成,合理的生、储、盖组合关系为油气聚集创造了条件。由于差异压实作用,造成潜山斜坡部位坡降加大,在洪水、地震等条件的诱发作用下,三角洲前缘沉积物垮塌形成了多期次的滑塌浊积岩。不同沉积微相沉积砂体由于砂体厚度、分布面积、储集物性、分布位置等不同,其储量丰度不同。其中,水下分流河道砂体储量丰度最高,其他依次为河口坝、浊积扇、前缘席状砂和远砂坝。

Analysis of the background data based on core facies,electrofacies and seismic facies illustrates that the Suizhong 36-1 oilfield in Bohai Sea comprises three depositional systems,including delta,turbidite fan,and shallow and semi-deep lacustrine facies.Rational association of source,reservoir and caprock had provided conditions for hydrocarbon accumulation.Differential compaction had resulted in increased slope gradient on the buried hill.The delta front deposit collapsed as induced by flood and earthquake and formed multistage fluxie.The sand bodies of different sedimentary microfacies have different reserves abundance due to different sand thicknesses,distribution areas,petrophysical properties,and locations.The sand body of underwater distributary channel has the most reserves abundance;others in turn are mouth bar,turbidite fan,front sand sheet and distal bar.