DY凹陷南坡沙河街组沙四段(ES4)储层以低渗透为显著特征,孔隙结构复杂,给储层有效性评价带来一定的困难.根据岩心、铸体薄片、压汞等分析资料,对ES4低渗透砂岩储层孔隙结构进行分析,将其细分为3大类5小类.基于分形理论,利用压汞曲线、核磁共振T2谱及CT图像分别探讨了分形维数和孔隙结构类型间的关系,明确了分形维数可以用于孔隙结构类型的表征,并试图推广运用到测井曲线上,但发现测井曲线分形与孔隙结构类型关系不明显,进而通过J函数提取了更能反映孔隙结构的参数R(K/φ)曲线,而不同孔隙结构类型的储层可通过求取R曲线的盒维数(DR)进行表征,并将声波、密度曲线结合起来,进行三维交会,基本能够识别井筒剖面不同层段的孔隙结构类型.%The low permeability is the salient features of ES4reservoirs in the southern slope of Dongying sag.And the complex pore structure makes it difficult to evaluate reservoir.The pore structures of low permeability sandstone reservoir in ES4are analyzed based on core physical properties, casting thin sections and mercury injection data and are divided into 3 categories and 5 subcategories.From the point of view in fractal theory, the characterization of the types of pore structures by the fractal dimensions is confirmed after the discussion of the relationship between them respectively based on the mercury injection data, the T2 spectra of NMR and the CT images.It's a failed use in the log curves because of their regular relationship, but it's found that the box dimension of the curves of parameter R(K/φ) extracted from the function J works well in the characterization of the different types of pore structures and then tell the map art in the cross plot of curves like R, density, GR in the profile of wells.
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