锦99块扇三角洲河口坝层次界面分析

Hierarchical interface analysis on estuary dam of fan-deltas in Jin 99 block

锦99块构造位于辽河断陷盆地西部凹陷西斜坡的西南部,其主力产油层为扇三角洲沉积。通过对岩心、测井等资料分析,认为该区发育6种岩相。利用高分辨率层序地层学,采用层次分析法对锦99块扇三角洲河口坝进行深入剖析,划分出5级层次界面。通过研究发现河口坝复合体之间的五级界面以水平状厚泥岩层为主,能够很好遮挡油气;单一河口坝之间的四级界面以低角度的斜状泥质夹层为主,偶见低斜度的物性夹层,为小层内的渗流屏障;单一河口坝内部增生体之间的三级界面以粉砂质沉积为主,稳定性差,对油气起到局部遮挡或缓冲作用。

The main producing pay zones in Jin 99 block are fan- delta deposits,which are located in the southwest of the west slope of the western depression in Liaohe Basin. Based on the data analysis of core and logging,it is considered that six types of facieses were developed in the area. With the use of high-resolution sequence stratigraphy and analytic hierarchy process,the estuary dam of fan-deltas in Jin 99 block was further divided into five orders of hierarchy interfaces. The studies showed that the fifth order of hierarchy interface between mouth dam complexes is mainly horizontal thick shale,which can well prevent oil and gas migration. The fourth order of hierarchy interface between single debouch dams is mainly inclined- shale interlayer with low angle,occasionally physical interlayer with low slope,which is seepage barrier in small layers. The third order of hierarchy interface between accretion sandbodies in single debouch dam is mainly silty deposit,which has poor stability and can keep out or buffer oil and gas migration.