低孔渗储层流动单元的划分方法与评价

Classification Method and Evaluation of Flow Unit in Low Porosity and Permeability Reservoir

XX凹陷N地区为低孔低渗储层,开发难度大,为合理高效开发,此文结合岩心物性分析、岩心压汞分析、试气分析和测井分析等资料,利用FZI值将研究区储层划分为三类;对各类流动单元的毛管压力曲线特征、物性特征、孔隙结构参数以及渗流性能参数进行研究,分类后的三类储层对应毛管压力曲线特征(孔隙结构特征)和渗透性差异明显,且每一类储层孔隙结构、渗透性等特征基本一致;利用实际井资料对比与验证,说明利用FZI值划分储层类型,区分效果明显,验证了FZI值划分储层类型的合理性。利用FZI值划分低孔低渗储层类型,对于调整注采井网、提高采收率等具有重要意义。

The reservoir in N area of XX Sag is very difficult to develop due to its low porosity and permeability. According to the analysis of a series of data including those of physical property and mercury injection from core samples, gas test and well logging etc., the reservoir can be divided into three categories by flow zone index（FZI） values. The study of capillary pressure curves, physical property data, pore structure parameters and percolation parameters in different flow unit shows that there are obvious differences in the capillary pressure curves （pore structure） and permeability values among the different types of reservoirs, but good consistency in each type of reservoir. The comparison and verification with well data reveal that the classification of reservoir type by FZI is reasonable. It is significant in adjusting injection-production well patterns and enhancing oil recovery.