陕甘宁盆地奥陶系白云岩依成因可分为云坪型准同生白云岩、膏盐湖型准同生白云岩、受改造的云坪型准同生白云岩、回流渗透白云岩、混合水白云岩、埋藏白云岩和淡水白云岩（石）。奥陶系冶里—亮甲山组、马五段受改造的云坪型准同生白云岩和马六段、马五段的混合水白云岩，由于它们沉积在古陆周缘，受到了不整合面发育过程中溶蚀作用的改造，最终使储集性能变好。 The Ordovician dolomites in the Shan-Gan-Ning basin can be classified into the Yunping-type syn-syenite dolomite, the gypsum-born dolomite in the Gaolan Lake, the altered Yunping quasi-syngenetic dolomite, the backflow infiltration dolomite, Water dolomite, burial dolomite and freshwater dolomite (stone). The Ordovician Yili-Liangjishan Formation, the Ma5 Member altered Yunping quasi-syngenetic dolomite, and the M6 ​​and M5 mixed-water dolomites were unconformity due to their deposition on the periphery of ancient land Surface modification of the dissolution of the evolution process, and ultimately make the reservoir performance better.