Abstract: The He-8 member of Shihezi formation in Sulige gas field is the main production zone, with the formation water salinity of 0.79~99.87g/L and CaCl2 water type. It is found that there exists the independent distribution of gas layer or water layer in this member, and besides, there are 3 types of distribution features, including gas/water layer, interbedded gas/water layer and same gas/water layer in sand body of one interval. Through gas test data and formation water analyses from 119 wells, the formation water salinity, the ions concentration ratio distribution and metamorphosed degree are drawn. Finally, the relationship between the formation water property and distribution and the natural gas enrichment is determined, and the favorable areas with gas exploration potentials are predicted.

Key words: Ordos basin, He-8 member, formation water, salinity, gas-water distribution