Prediction of hydrate deposition in pipelines to improve gas transportation efficiency and safety

Abstract The significant amounts of hydrocarbon resources (oil, natural gas, and gas hydrates) present in subsea and cold regions represent one of the most pre-dominant resources in the future. However, the deposition of gas hydrates in the transportation pipeline significantly decreases the efficiency and the safety of energy recovery. In this study, a novel model for forecasting hydrate deposition in gas transportation pipelines was established by considering the hydrates generated from the condensate water on the cold wall and the condensate drops in the gas core. By using the proposed model, the location and severity of hydrate deposition in pipelines can be quantitatively forecasted and analyzed. Compared with the existing methods, the average relative error between the calculated pressure drop and the experimental data was reduced from 34.98% to 7.43%, and the mean relative error between the calculated thickness of deposited hydrates and the experimental results was within 9.17%. The calculated results indicate that the deposited hydrates are unevenly distributed along the pipeline, and the deposition of hydrates formed from the condensate drops in the gas core is essential during the calculation of hydrate deposition in gas pipelines. The proposed model exhibits its good reliability for the water-saturated gas flow systems, but its applicability for the flow pattern with the existence of free water remains to be analyzed. Thus, the proposed model provides an effective support for the high-efficiency and high-safety development of hydrocarbon energy in subsea and cold regions.