鄂尔多斯盆地中奥陶统平凉组沿盆地西、南缘呈“L”型分布，厚度较大，岩性主要为灰岩、泥质灰岩，局部夹薄层泥岩。以往研究认为平凉组局部层段富含泥质，可作为下古生界烃源岩，但非勘探目的层。从中奥陶世华北地台南缘大地构造背景出发，分析了鄂尔多斯盆地南缘中奥陶统平凉组的沉积环境和沉积模式。综合露头剖面与井下岩心分析资料及岩性组合特征，探讨了平凉组成藏要素及其空间配置关系，指出平凉组局部层段发育的礁滩相沉积，经后期成岩白云岩化可形成有效的白云岩储层，与邻近的富含泥质层段共同形成自生自储型成藏组合，具有一定的资源潜力。

Middle Ordovician Pingliang Formation is in the shape of “L” along the western and southern margin of Ordos Basin, and mainly consists of limestones and muddy limestones partly with thin mudstones and has bigger thickness. Previous research considered that local intervals of Pingliang Formation were rich in mud and could act as Lower Paleozoic hydrocarbon source rocks, but they were not exploration targets. Based on the geotectonic background of the southern margin of the North China platform of Middle Ordovician, the sedimentary environments and sedimentary patterns of Pingliang Formation are analyzed. The reservoir\|forming factors and their space arrangement are researched using outcrop section, downhole core data and lithologic combination feature. The result shows that reef flat facies deposition is developed in some parts of the Pingliang Formation and they form dolomite reservoirs through later diagenesis and dolomitisation. These dolomite reservoirs and neighboring muddy intervals form reservoir\|forming combination of self-generation and self-reserve, and have exploration potential.