Integrated evaluation of deliverability in low permeability lithologic gas reservoirs in Santanghu Basin

It is necessary to carry out reasonable deliverability study for a single well, sincedeliverability test of gas well in low permeability lithologic reservoirs is difficult and seldom and the capacity analysis data are little utilized. The sensitivities of characteristic parameters of single-point deliverability equation to permeability, effective thickness and skin coefficient are analyzed. The result shows that the common experience productivity formula is invalid for the gas reservoirs with different properties, complex boundary and strong heterogeneity. The modified isochronal test and the single-point method are integrated to determine the reasonable deliverability: the deliverability in Qigu Group in Niu 101-Ma 1 block is 1.5×104 m3/d, and it is 1.0×104 m3/d in Toutunhe Group.