Effect of natural gas C₆⁺ composition obtained by different quantitative methods on calculation of hydrocarbon dew point

The calculation of hydrocarbon dew point from natural gas composition data is an important detection method for obtaining hydrocarbon dew point. Natural gas composition analysis has related methods and standards, but there are different quantitative and data processing methods for C₆⁺ composition analysis. In this paper, the main factors influencing the calculation result of hydrocarbon dew point are summarized, among which the difference between different quantitative methods of C₆⁺ extension analysis for predicting hydrocarbon dew point is emphatically discussed. Two real natural gas samples were analyzed by gas chromatography. The experimental data were obtained by different quantitative and data processing methods for C₆⁺ extension components, and the hydrocarbon dew point of natural gas is predicted by using composition data of natural gas. The results show that C₆⁺ components were classified according to the carbon number from C₆ to C₁₆, in which benzene, toluene, cyclohexane and methyl cyclohexane were respectively determined, and the complete analytical data of natural gas composition were obtained. The average deviation between the hydrocarbon dew point calculated through natural gas composition data and directly measured hydrocarbon dew point is less than 3 ℃.The consistency of hydrocarbon dew point obtained by calculation method and direct determination method is preliminarily verified.