基于主成分分析法的近/相似物性致密砂岩储层差异微观主控地质因素研究

Study on Microcosmic Main Controlling Geological Factors of Differences in near/similar Tight Sandstone Reservoir Based on Principal Component Analysis

致密砂岩储层微观孔喉结构复杂、非均质性强,各特征参数间具有相关性,导致储层描述或定量表征结果存在偏差,严重制约储层分类评价和高效开发.以鄂尔多斯盆地某油区长6致密砂岩储层为例,基于高压压汞、物性测试分析、储层分类结果,运用主成分分析法,按照荷载值最大原则,优选出引起近/相似物性储层差异的微观地质主控因素.研究结果表明,Ⅰ、Ⅱ、Ⅲ、Ⅳ类储层内部的个体间差异主控因素分别为:孔喉分选系数与中值半径、退汞效率与最大进汞饱和度、中值半径与最大进汞饱和度、分选系数与歪度系数.研究结果加深了对近/相似物性致密砂岩储层差异成因机理的认识,为致密砂岩储层精细描述、定量表征和高效开发具有较好的指导意义.

The complex microscopic pore-throat structure,strong heterogeneity and correlation among characteristic parameters of tight sandstone reservoir lead to deviation of reservoir description or quantitative characterization results,which seriously restricts reservoir classification,evaluation and efficient development.Taking Chang 6 tight sandstone reservoir in an oil area of Ordos Basin as an example,based on high-pressure mercury intrusion test,physical property test and reservoir classification results,the principal component analysis method and the principle of maximum load value are used to optimize the micro geological main controlling factors that cause the individual differences within the reservoir with near/similar physical properties.The results show that the main controlling factors of individual differences in type Ⅰ,Ⅱ,Ⅲ and Ⅳ reservoirs are as follows:sorting coefficient and median radius,mercury removal efficiency and maximum mercury saturation,median radius and maximum mercury saturation,sorting coefficient and skew coefficient.The results of this study deepen the understanding of the genetic mechanism of the difference between tight sandstone reservoirs with the near/similar physical properties,and have a good guiding significance for the fine description,quantitative characterization and efficient development of tight sandstone reservoirs.