鄂尔多斯盆地北部为气源运移的指向区，具有较好的生储盖条件。下古生界气源岩为下奥陶统马家沟组碳酸盐岩，上古生界气源岩为石炭系太原组和二叠系山西组碎屑岩；下古生界储集层为马家沟组风化壳，上古生界储集层为石炭系本溪组、太原组和二叠系山西组、下石盒子组，前者以碳酸盐岩为主，后者以碎屑岩为主；下古生界风化壳气藏的区域盖层为石炭系底部的泥岩、铝土岩及铝土质泥岩，上古生界气藏的区域盖层为二叠系上石盒子组泥质岩。由于天然气聚集于两个不同的领域，其成藏各具特点，因而天然气富集控制因素就有所不同：下古生界天然气富集主要受气源、区域性岩相变化、盖层及古地貌影响，而控制上古生界天然气富集的决定因素有气源、砂岩体、局部构造的发育程度及源岩生烃期与圈闭形成期的匹配。 The north part of Ordos Basin is the source area for gas source migration, which has good conditions for reservoir formation and cover. Lower Paleozoic gas source rocks are Lower Ordovician Majiagou carbonate rocks, Upper Paleozoic gas source rocks are Taiyuan Formation and Permian Shanxi Group clastic rocks, and Lower Paleozoic reservoirs are The Majiagou weathering crust and the Upper Paleozoic reservoirs are Carboniferous Benxi Formation, Taiyuan Formation and Permian Shanxi Formation. The former are mainly composed of carbonate rocks and the latter are mainly clastic rocks ; The regional caprock of the lower Paleozoic weathering crust gas reservoir is mudstone, bauxite and bauxitic mudstone at the bottom of the Carboniferous, and the upper caprock gas reservoir is the Permian Upper Shihezi Formation mudstone. Since natural gas accumulates in two different areas and has various characteristics of hydrocarbon accumulation, natural gas enrichment control factors are different: gas accumulation in the Lower Paleozoic is mainly affected by gas source, regional lithofacies, The determinants of gas enrichment in Upper Paleozoic include gas source, sandstone body, degree of local tectonic development, and matching between source rock formation period and trap formation period.