鄂尔多斯盆地上古生界碎屑岩相对高渗储集层成因及分布*

鄂尔多斯盆地上古生界发育 “粒间孔型石英砂岩”、“溶孔型石英砂岩”、“粒间孔—溶孔复合型长石砂岩”3类相对高渗储集层。结合鄂尔多斯盆地地质背景，分析了该地区上古生界3类相对高渗储集层的岩石结构、组分与物性等基本特征，详细探讨了沉积环境、成岩作用、构造活动对鄂尔多斯盆地上古生界各类相对高渗储集层形成的控制机理，并在此基础上，依据与物源的距离、沉积相类型及砂体分布、孔隙类型、颗粒成分及粒度粗细、杂基成分及含量、储集层最大埋深、后期构造运动等因素，对主力勘探层系山西组二段和下石盒子组八段进行了储集层优劣分级综合评价，认为受高石英含量母岩控制的沉积体系、辫状河高能沉积相带和强溶蚀、弱压实的有利成岩相带分布区是鄂尔多斯盆地上古生界碎屑岩相对高渗储集层的主要发育区域。

Origin and distribution of higher permeable reservoir of the Upper Paleozoic in Ordos Basin

Three kinds of higher permeable reservoirs including intergrain pore quartz sandstone,dissollution pore quartz sandstone,intergrain and dissolution complex pore feldspathic arenite were developed in the Upper Paleozoic of Ordos Basin.Based on analysis of rock texture,component and physical properties of the three types of sandstones,the control mechanism of high quality reservoir,such as sedimentary environment,diagenesis and tectonism,were discussed in detail.According to the transport distance of sediments,sedimentary facies,distribution of sandstone,pore types,composition of grain,burial depth and tectonic movements in later periods, the reservoir of the main exploration measures were appraised and classified,and the higher permeable reservoir’s distribution pattern is summarized.It is known that the sedimentary system of high quartz content,high-energy sedimentary facies of braided fluvial facies,strong corrossion and weak compaction diagenetic facies are considered to be the dominating distribution areas of higher permeable clastic reservior in the Upper Paleozoic of the Ordos Basin.