真武油田辫状河心滩微相储层构型研究

Study on the texture of braided bar microfacies reservoirs in the Zhenwu oilfield

真武油田是江苏油田20世纪70年代投入开发的油田,垛一段辫状河储层剩余油分布分散,挖潜难度大,因而针对辫状河心滩微相储层构型开展研究。研究区真12断块E2s16砂层组发育了典型的心滩沉积,砂体厚度大,多层叠置。通过心滩微相储层构型界面的分析以及单期次心滩在纵向和平面上的识别,真12断块E2s16砂层组可以划分出3个单期心滩,在平面上分布于真49、真106-3、真91井为中心的区域,单期次心滩中心部位夹层少,厚度薄,水流的下切作用相对明显,心滩微相的不同位置发育不同的夹层特征。心滩微相包含了洪泛砂砾岩体、静水侧积砂体和"落淤层"3个储层构型要素,在前人心滩构型模式基础上加入了侧向加积的层段和期间落淤层的体现,从而建立更为合理的心滩微相构型模式。

The Zhenwu oilfield was put into development in the 70 s last century as a part of the Jiangsu oilfield. Since remaining oil in the Duo- 1 member braided stream reservoir has a sporadic distribution,difficult for potential pooling,a study on the braided bar microfacies reservoir texture is conducted. In the study area – Zhen- 12 fault block,typical channel bar deposits were developed in the E2s1 6s and set and the sand bodies are thick with multi- layers superimposed. By means of analysis of interfaces in the channel bar microfacies reservoir texture as well as areal and vertical identification of single stage channel bar,three single stage channel bars can be divided in the E2s1 6s and set of Block Zhen- 12,which are distributed arealy in the areas centered by wells Zhen 49, Zhen 106- 3 and Zhen 91. The central part of a single stage channel bar is thin,having very few of interbed and relatively obvious downcutting of water flow. Interbed features vary in different positions of a channel bar microfacies. The channel bar microfacies includes three elements of reservoir texture: flooding glutenite terrane,sand accretion at still water side and'silt falling bed'. In the study,lateral accretion intervals are added and silt falling beds between stages are present additionally on the basis of channel bar texture mode suggested previously,establishing a more reasonable mode of channel bar microfacies texture.