鄂尔多斯盆地X区块致密砂岩储层非均质性研究

Study on the Heterogeneity of Tight Sandstone Reservoir in X District,Ordos Basin

苏里格气田是典型的低效致密砂岩气田,主力储集层石盒子组盒8段具有低孔、低渗、低丰度并且有严重的非均值性特点。储集岩石的基本属性之一是非均值性,油气储集层的油气藏开发效果和渗透性都受其严重制约和影响。应用分析化验资料研究储层岩性、物性和孔隙结构等特征,对鄂尔多斯盆地X区块盒8段储层非均质性从层内、层间和平面3个层面进行了深入分析。研究结果表明,研究区盒8段层内非均质性均为中等-较强;盒8上到盒8下砂体发育程度逐渐增大、层间非均质性依次增强;盒8下和盒8上钻遇率依次降低,平面上的侧向连续性逐渐变好,非均质性依次增强。

Sulige gas field is a typical of inefficient and tight sandstone gas field.The Member 8 of Shihezi Formation of the main reservoir has very serious traits including low porosity,low permeability,low abundance and heterogeneity.As a reservoir rock＇s basic attribute, the heterogeneity seriously inflences and restricts the infiltration characteristic of reservoir and the development of oil and gas reservoir. Based on test data, lithology,physical property and pore structure of the reservoir were studied, the heterogeneity of the Member 8 reservoir of Ordos Basin＇s X district was analyzed from three levels of layer, interlayer and plane. The results show that the heterogeneity of the Member 8 reservoir is moderate to strong in the research region; from top to bottom of the Member 8 reservoir, developmental degree increases gradually, the heterogeneity increases successively in the interlayer of the Member 8 reservoir; drilling-encounter ratio at the top and bottom of the Member 8 reservoir reduces successively, the later continuity becomes higher and the heterogeneity becomes stronger in the place of the Member 8 reservoir.