鄂尔多斯盆地高桥地区上古生界致密砂岩储层非均质性特征

为深入研究致密砂岩储层的非均质性，利用钻井岩心资料、测井资料和测试分析资料，对鄂尔多斯盆地高桥地区上古生界致密砂岩储层的非均质性进行了深入分析。结果表明，研究区山西组-下石盒子组储集砂体的非均质性与沉积作用关系密切，垂向加积作用导致储集砂体物性在垂向上表现为规律不明显的正韵律或突变正韵律；侧积作用导致储集砂体物性在垂向上表现为强烈的正韵律；前积作用导致储集砂体物性在垂向上表现为规律明显的反韵律。漫流沉积作用导致储集砂体物性在垂向上表现为变化不大或略微反韵律。从层内非均质性上看，盒8段和山西组储层均具有较强的非均质性。其中山2段的储层非均质性较山1段的强，盒8^下的储层非均质性较盒8^上的强。4个亚层中属盒8^上的均质性最好。从层间非均质性上看：不同层位差异较大。从平面非均质性上看，高桥地区盒8段和山西组储层在平面上不同地区表现出较强的非均质性。

Heterogeneity of the Paleozoic tight sandstone reservoirs in Gaoqiao Area of Ordos Basin

The heterogeneity characteristics of the Paleozoic tight sandstone reservoirs in Gaoqiao area of Ordos Basin are studied in detail in this paper by using core data,logging data,and test data.The results show that there is a close relationship between heterogeneity and sedimentation of the Shanxi Formation and Xiashihezi Formation sandbodies.The sandbodies formed by vertical accretion show vertical positive rhythm or flanges positive rhythm with no obvious trend.In contrast,those sandbodies formed by lateral accretion show strong vertical positive rhythm.Sandbodies formed by progradation have apparent vertical anti-rhythm.Sandbodies of overland flow deposition display little change or a slight vertical counter-rhythm.He8 and Shanxi Fm reservoirs show strong intralayer heterogeneity.The heterogeneity of Shan2 segment is stronger than that of Shan1,while the heterogeneity of lower He8 segment is stronger than that of upper He8 segment.Among these four sub-layers,the upper He8 segment is most homogeneous.Interlayer heterogeneity significantly varies among different layers.He8 segment and Shanxi Formation also show strong lateral reservoir heterogeneity in Gaoqiao area.