基于改进毛管压力曲线的非均质储层分级评价与应用

针对强非均质性储层精细开发的难题,以江汉盆地潜江组油藏为研究对象,采用改进毛管压力曲线特征参数与岩心基础参数相结合的方法,建立了储层量化指标分级评价体系,并将油层有效厚度与测井曲线有机结合,建立了毛管压力曲线簇归一化新方法。结果表明:基于改进毛管压力曲线的储层量化指标分级评价体系主要包含渗透率、起点压力、转折压力、中值压力和分类储层占比5种量化指标;潜江组油藏细分为Ⅰ、Ⅱ、Ⅲ、Ⅳ、Ⅴ、Ⅵ共6类储层,Ⅰ、Ⅱ类储层为渗流能力最优储集层,占整个潜江组油藏41.17%,Ⅲ、Ⅳ类储层主要为中低渗储层,占比超过50.00%,Ⅴ、Ⅵ类储层属于特(超)低渗储层,占比仅为7.77%。基于有效厚度的毛管压力曲线簇归一化方法计算简单,相对误差较小,可为储层分类评价后储层特征参数表征及对比提供途径。

Classification Evaluation and Application of Heterogeneous Reservoirs Based on Improved Capillary Pressure Curve

In view of the strong heterogeneity of the fine reservoir development, taking reservoirs in Qianjiang Formation, Jianghan Basin as the study object, a classification evaluation system of reservoir quantitative indicators was established in combination with the characteristic parameters of improved capillary pressure curve and the basic core parameters, and the effective reservoir thickness was organically combined with logging curve to develop a new method of normalization of capillary pressure curve family. The results showed that the classification evaluation system of reservoir quantitative indicators based on the improved capillary pressure curve mainly included five quantitative indicators: permeability, starting pressure, transitional pressure, median pressure and proportion; the reservoirs in Qianjiang Formation were subdivided into Ⅰ, Ⅱ, Ⅲ, Ⅳ, Ⅴ and Ⅵ types; Types Ⅰ and Ⅱ were the reservoirs with the best permeability, accounting for 41.17% of the all reservoirs, Types Ⅲ and Ⅳ were mainly the reservoirs with medium and low permeability, accounting for more than 50.00%, Types V and VI were the reservoirs with extra (super) low permeability, accounting for only 7.77%; the normalization method of capillary pressure curve family based on effective thickness was simple in calculation and low in errors, providing a basis for the characterization and comparison of reservoir characteristic parameters after reservoir classification and evaluation.