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鄂尔多斯盆地上古生界含油气砂岩属典型的低孔、低渗致密砂岩 ,储层成岩后生作用强烈 ,孔隙类型多样 ,结构复杂 ,有着严重的纵向和横向非均质性。利用常规的岩电实验确定阿尔奇结构参数面临如下困难 :①岩心致密 ,即使采用目前最先进的半渗隔板法 ,其效果也不理想 ;②储层应力敏感性强 ,地层与地面条件的孔隙结构差异大 ;③标准样品的代表性有限。近年来的研究表明 ,利用常规岩电实验参数解释得到的含水饱和度明显偏离油藏实际情况。文章针对这一问题 ,利用密闭取心分析资料对阿尔奇公式中的岩石电学参数进行了刻度。结果表明 ,对储集类型和孔隙结构多变的储层 ,利用固定不变的a、m参数计算得到的含油气饱和度无法满足储量计算精度要求。令a =1,得到m与 φ的相关式为m =1.43+1.411φ ,该式相关性良好 ,实际使用结果使饱和度的解释误差比原方法降低了 10 %以上
The Upper Paleozoic petrological sandstones in Ordos Basin are typical low-porosity and low-permeability tight sandstones. The diagenesis of the reservoirs strongly influences the diagenesis of the reservoirs. The reservoirs have diverse pore types and complex structures with severe longitudinal and lateral heterogeneities. It is difficult to determine the Archie structure parameters by using the conventional rock electric experiments: ① The core is dense, and the effect is not satisfactory even if the most advanced semi-permeable diaphragm method is adopted; ② The reservoir stress sensitivity is strong, and the formation and ground conditions Pore structure difference is large; ③ the representativeness of the standard sample is limited. In recent years, studies have shown that the use of conventional experimental parameters to explain the experimental rock water saturation significantly deviated from the actual situation of the reservoir. In order to solve this problem, the article uses closed coring analysis data to scale the rock electrical parameters in Archie’s formula. The results show that for the reservoirs with variable reservoir type and pore structure, the saturation of oil and gas calculated by a, m parameters can not meet the requirements of the accuracy of reserves calculation. When a = 1, the correlation between m and φ is obtained as m = 1.43 + 1.411φ, and the correlation between the two equations is good. The actual use result reduces the interpretation error of saturation by more than 10% compared with the original method