Lowest limit for the gas-bearing capacity of reservoirs in the eastern Sulige gas field, Ordos Basin

According to the definition and characteristics of the lowest limit for reservoir gas-bearing capacity, we carried out statistical and accumulation mechanism studies in the eastern Sulige gas field in the Ordos Basin. The two methods reached a similar conclusion. The lowest limits for the porosity and permeability of the eighth member of Shihezi Formation (He8) are 2.223% and 0.005 7×10^-3 μm², respectively. The lowest limits for the porosity and permeability of the first member of Shanxi Formation (Shan1) are 1.605% and 0.004 4×10^-3 μm², respectively, which are both higher than those of He8. The lowest limit for reservoir gas-bearing capacity is negatively related to charging force. We collected samples from the reservoirs with physical properties close to the lowest limit, and tested their gas saturation. The gas saturation of the reservoirs with physical properties close to the lowest limit is extremely low, and obviously increases in reservoirs with better physical properties. Theoretical analyses are consistent with coring results.