Natural gas hydrates pose serious difficulties to pipeline operators, gas producers and processors in the oil industries where they plug the production lines, transmission lines, and choke production equipment. Thus, reducing production capacity or even stop production. Several models have been developed using thermodynamic method and numerous correlations have been developed using gravity method in order to predict the conditions for hydrates formation without considering water vapour pressure has one of the parameters that hydrates formation depend on. Thus, the existing correlations have some limitations.
The proposed empirical correlation was developed using gravity method and statistical analysis software to illustrate the mathematical expression that correlate hydrate-formation temperature, pressure, water vapour pressure, and specific gravity of hydrocarbon systems. The correlation was developed using 300 data points from literature. The correlation was validated with 26 data points not included in the optimization and compared with some of the existing correlations.
The results of statistical analysis show that the proposed correlation indicates highest value of correlation coefficient (R2 = 0.996), and lowest average absolute deviation value (AAD = 1.84 °F) and lowest value of average absolute percentage relative error (AAPRE = 0.284°F) among the existing correlation compared with. These results indicate that the proposed empirical correlation predicts closest to the experimental values compared to the existing ones.