| Y gas field is located in the Jinxi flexural fold belt in Ordos Basin. In recent years, gasexploration obtains important breakthrough with high-yield gas reservoir and multi-portindustrial air well being found, showing good prospects for gas exploration in the area.Y gas belongs to the hidden gas reservoir with low porosity, low permeability, lowabundance and large distribution area. Compared with structural reservoir, hidden gasreservoir has characteristics of complex formation mechanism and distribution law, difficultexploration and high technical requirements.Main gas reservoirs overlie in the strata of PermianTaiyuan, Shanxi and Shihezi,which parallel sunconformity to underlying strata of Middle Ordovician MajiagouFormation, the overlying strata is lower Triassic Liujiagou.Stable settlement of earlierstructures laied the foundation for marine source rocks development in the group Taiyuan,Benxi and Shanxi. Sandstone developed in the Shanxi and Xiashihezi group becamereservoirs, mudstone developed in the Shangshihezi and Shiqianfeng group became cap rock,and they three together form source-reservoir-cap assemblages. The continual uplift of latemovement controlled the direction of gas migration and accumulation, and the multilayerdevelopment of lithology–diagenetic traps constituted the swells on the storage-type,self-generated self-storage type and across the three-reservoir-cap combination.In summary, the paper studied the Mesozoic geology，set up Upper Paleozoic reservoirforming modes of natural gas combined with analyzing typical gas reservoir，and furthersummarized the enrichment law and exploration potential of natural gasthroughcomprehensive research based on Paleozoic sedimentary characteristics and post-tectonicevolution，migration of hydrocarbon from source rocks and the causes of high-permeabilityand gas pool forming evaluation of the potential for natural gas exploration, which provideideas for the next step exploration of subtle reservoirs in the area. |
