Based on the research of gas pool forming conditions of Shan 2 Member in Dongshadai area of Yulin gas field in Ordos basin, the distribution rules of gas can be concluded that coals, swap dark mudstones and delta front sandbodies are well-developed vertically, the conditions of reservoir-forming combination for self-generation and self-preservation are processed; the sandbodies developed in submerged distributary channel and mouth bar microfacies of delta front have high content of quartz, which have good physical properties and high gas production. There is a good relationship between the distribution of gas pools and the maturity of sandstone, the value 6 of maturity index(86% quartz content) can be used to delineate the zones of gas enrichment and productivity. This rule can guide the exploration and production of this area in next step.

Yulin gas field; gas distribution; Dongshadai; Shan 2 Member; quartz content; maturity