As the oilfield development entered the middle and late stage,difficulty of tapping residual oil increases when the relationship between oil and water becomes more and more complex.Fine geological research based on reservoir architecture becomes the key to tap residual oil.The hierarchy interface analytical method was applied in the article to analyze the internal architecture characteristics of sandy braided-river in the 4th area of L Oilfield in Bohai Bay Basin based on outcrop,core,modern deposits and dense well logging data.On the basis of architecture reverse classification scheme,the architecture interface of braided-river in the study area was divided into 6-12 levels considering positive sequence classification.Based on the experience formula for sandy braided-river reservoir,modern deposits constraints and stratigraphic correlation between closely spaced wells,single braided channel belt,braided bar and braided channels and interlayers within braided bar were quantitatively characterized by grade.A set of methods for quantitatively characterizing different levels of sandy braided-river were developed,and the characteristics of single braided channel belt,braided bar and braided channels and interlayers within braided bar were determined as the three levels of the architecture.There are four filling patterns for the braided channels,including sand filling,half-mud filling,mud filling and remaining mud filling,and then the genesis of different filling patterns was analyzed.%随着油田开发进入中后期,油水关系更加复杂,剩余油挖潜难度随之增大,基于储层构型的精细地质研究成为油田剩余油挖潜的关键.综合利用露头、岩心、现代沉积和密井网等资料,应用层次界面分析法,深入解剖渤海海域L油田4区砂质辫状河储层构型特征.以构型倒序分级方案为基础,参考构型正序分级方案,将研究区辫状河储层构型界面分为6-12个级次.依据砂质辫状河储层经验公式、现代沉积和密井网井间对比,分级次对砂质辫状河单一辫流带、心滩坝和辫状河道及心滩坝内部夹层进行定量表征,形成一套适用于砂质辫状河储层不同级次构型单元的定量表征方法;明确单一辫流带级次、心滩坝和辫状河道级次及心滩坝内部夹层级次3个层次的构型特征.提出辫状河道具有砂质充填、半泥质充填、泥质充填和残存泥质充填4种充填模式,并分析不同充填模式的成因.
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