As an essential basic data in natural-gas research,the deviation coefficient is also a correction factor that ought to be con-sidered when the ideal equation of state is applied to actual gas.It has been widely used in the reserve calculation,the gasfield devel-opment scheme planning,the evaluation on reservoir performance,and the oil and gas storage and transportation.So,taken gas res-ervoirs of the Silurian Longmaxi Formation in two wells,Luzhou shale gas field,southern Sichuan Basin,as examples,the measured deviation coefficient was compared with the other from some approaches(for example,equation of state,empirical formula,and virial equation)commonly used for deep shale gas reservoirs under different temperature and pressure.Finally,an optimal method to calcu-late this coefficient was selected.Results show that the relative error between one from the extended virial equation and the measured result is always less than 3.51%,which is the lowest among the selected methods.Thus,this virial equation can help mitigate the error of gas volume deviation caused by improper methods.It enjoys strong applicability and meets the demand of evaluation on deep shale gas reservoirs in all stages of exploration and development.
万方数据
维普
