摘要
鄂尔多斯盆地奥陶系沉积时期，处于“三隆两鞍两坳陷”的古构造格局。三个隆起在平面上呈“L”型展布．共同控制着奥陶系的沉积相带．进而控制着不同类型储层的区域展布。奥陶系主要的储集类型包括东部坳陷的盐下储集体、古隆起斜坡带的风化壳岩溶储集体、古隆起鞍部的马四段白云岩储集体、古隆起西部的中奥陶统重力流储集体、古隆起南部斜坡带的生物礁储集体。风化壳岩溶是最有利的储集体．在该储集体中目前已找到了靖边大气田。其他4种类型储集体的勘探虽然还没有取得实质性进展，但结合储层特征及油气运聚分析，仍存在较大的勘探潜力．是开拓鄂尔多斯盆地下古生界油气勘探新领域的关键所在。
Ordos basin had a paleotectonic framework of ＂three uplifts-two saddles-two depressions＂ in Ordovician sedimentary age. Taking an ＂L＂ in plane, the distribution of the three uplifts controlled the Ordovician sedimentation, and then controlled the regional distribution of various reservoirs. The main reservoir types of the Ordovician include the following five -- reservoirs under salt dome in the eastern depression, residual karst reservoin in the slop belt of the paleo-uplift, dolostone reservoirs of the Forth Majiagou Member in the saddle part of the paleo-uplift, mid-Ondovician gravity flow reservoirs in the western paleo-uplift, and bioherm reservoirs in the south slope belt of the paleo-uplift. The residual karst is the most favorable reservoir, in which the large Jingbian gas field had been found. According to reservoir features and analysis of migration and accumulation of oil/gas, the other four types of reservoixs have large exploration potential, though there is no substantial progress of exploration in the four types. They are master key for opening up new fields of exploration in Lower Paleozoic of Ordos basin.
