鄂尔多斯盆地上古生界砂岩储层特征及控制因素分析

Analysis on Controlling Factors and Sandstone Reservoir Characteristics of the Upper Paleozoic in Ordos Basin

结合大量岩石薄片、储层物性、压汞曲线资料的分析,对鄂尔多斯盆地不同区块上古生界主要气层段的岩石学特征、物性特征、孔隙结构及孔隙类型等进行深入对比研究,分析了影响储层碎屑组分、储集性能和平面分布的主要因素。研究表明,上古生界砂岩储层非均质性强,普遍具有低孔-低渗、孔喉偏小的特征;物源体系控制着砂岩组分的差异,由西至东石英含量减小,岩屑含量增加,长石含量仅在盆地西部边缘地带较高;沉积体系的多样性决定了储层储集体类型的多样性和分布规律;成岩作用对储集层发育的控制是多方面的,由溶蚀作用产生的次生孔隙是主要储集空间。

Lithologic,physical property,pore structure and pore types of the main gas zones of the upper Paleozoic System in different blocks of Ordos Basin were studied by analyzing a large number of thin sections,physical property and mercury injection data,the influence factors of reservoir clastic components,reservoir properties and its plane distribution were studied.The results show that heterogeneity is strong in the upper Paleozoic sandstone reservoir,it generally has the characteristics of low porosity and low permeability and small pore throat.Sandstone components are controlled by the source system,quartz content is reduced from the west to the east and debris content is raised,feldspar content is higher only in the west of the basins edge,diversity of depositional system determines the diversity of reservoir types and distribution;the influence of diagenesis on the reservoir is from various areas,secondary pores produced by corrosion is the main reservoir space.