鄂尔多斯盆地中东部山2段储集层岩性微观特征差异性的地质意义

通过大量薄片观察、扫描电镜、阴极发光等分析，并结合储集层物性、压汞等分析资料，研究鄂尔多斯盆地中东部山2段石英砂岩与岩屑砂岩微观储集特征的差异。石英砂岩石英含量高，杂基和软岩屑含量低，几乎不含长石；岩屑砂岩则石英含量低，杂基和软岩屑含量高，普遍含少量长石。根据石英砂岩与岩屑砂岩的石英颗粒表面特征的显著差异分析，石英砂岩是清水高能化学环境的沉积，沉积速率缓慢，具有以粒间孔为主的复合型孔隙组合，储集性好，勘探前景广阔；岩屑砂岩是混水低能、地表化学作用较弱环境的沉积，沉积埋藏作用迅速，孔隙发育差，仅见少量粒内溶孔，储集性差，勘探效益不明显。

Difference of reservoir microscopic features of the quartz sandstone and litharenite of the 2nd Member of Shanxi Formation, Upper Paleozoic in middle east Ordos Basin

By the analysis of a lot of slice-observing,SEM and cathode luminescence,combining with the physical property of reservoir and the mercury intrusion curve,the difference of reservoir microscopic features between quartz sandstone and litharenite of 2~(nd) Member of Shanxi Formation, Upper Paleozoic,middle east Ordos Basin,indicates that the quartz sandstone has the high quartz,low matrix,low soft lithoclast and few feldspar,and that the litharenite has the property of low quartz,high matrix,high soft lithoclast and a little feldspar.The obvious surface difference between the quartz sandstone and litharenite shows that the quartz sandstone is deposited slowly in clear water and high energy environment,and it possesses a complex porosity combination and gives priority to intragranular pores,it has broad prospects for explorations.The litharenite is the sediment of mixed water,low energy environment and weak chemical effett of the earth's surface,is quickly buried,with bad porosity,few intragranular solution void and poor reservoir property,and a poor prospecting.