Quantitative hydrate deposition prediction method and application in deep-water or permafrost gas pipelines

Abstract Hydrate formation in pipelines seriously affects the efficiency of energy transmission. Adopting the production process of gas pipelines in deep-water or permafrost regions as the engineering application background, hydrate formation and deposition characteristics at different locations in gas pipelines are analyzed to realize the quantitative prediction of high-risk areas and degree of hydrate plugging in pipelines. A typical deep-water gas pipeline in the South China Sea is selected as an example. The calculation results show that the long-distance pipeline exhibits an obvious hydrate blockage risk area, which occurs 700-3200 m away from the pipeline inlet. The high-risk area of hydrate plugging in the system moves upstream of the pipeline with decreasing ambient temperature. The risk of hydrate blockage increases with decreasing pipeline inner diameter. The established quantitative prediction method for hydrate deposition in deep-water or permafrost gas pipelines accurately locates high-risk areas of hydrate plugging, which could effectively guide hydrate prevention and notably reduce the cost of hydrate control in deep-water or permafrost gas pipelines.