基于储层构型的流动单元划分及对开发的影响

Flow Units Classification Based on Reservoir Architecture and Its Influence on Reservoir Development

三角洲沉积储层非均质性强,储层内部渗流特征复杂,制约油藏高效开发。以南湖油田E1f43油藏为例,采用基于储层构型的渗流屏障识别技术及基于多参数聚类分析和逐步判别的流动单元划分方法,结合开发动态资料,开展了渗流屏障分布规律和储层流动单元发育特征研究,分析了不同类型流动单元组合模式的连通关系,总结了渗流屏障和渗流差异对开发的影响。结果表明:(1)研究区发育连片状和条带状2种储层砂体类型,其中,条带状储层因注采井砂体分别存在于砂体和渗流屏障内而产生注水不受效,剩余油富集;(2)研究区发育5类流动单元,以II～III类为主;(3)储层连通砂体内部存在5种不同的流动单元组合模式,不同模式下的储层砂体连通关系存在差异,连通砂体内不同流动单元间形成渗流差异界面,使连通体内形成弱连通或差连通关系,制约油藏开发,造成剩余油大量富集。

Reservoir heterogeneity is severe and fluid flow is very complex in delta reservoir,which limits the reservoir development. Taking E1 f 43 reservoir of Nanhu Oilfield as an example,flowing barrier recognition method based on reservoir architecture and flow unit classification method based on multiparameter cluster analysis and stepwise discriminate analysis are used. Flow barrier distribution and flow unit development rule are studied with the above methods and development data. Connection of different flow unit composite models is analyzed and the influence of flow barrier and flow difference on oil development is summarized. The study revealed that：（1）developed two kinds of reservoir sandbodies,sheet sand and stripped sand. In stripped sand,water injection is usually invalid because the injection well and oil well are separately in sand and flow barrier. This forms remaining oil.（2）Developed 5 types of flow units and types II and III are the main types.（3）There are 5 different flow unit composition model in connected sand bodies which have different connectivity,which form flow difference surfaces inside connected sand bodies and weaken the permeability. These surfaces limit the reservoir development and enrich remaining oil.