基于流固耦合的水下采油树输油管道传热与保温三维数值模拟

Three-dimensional Numerical Simulation on Heat Transfer and Thermal Insulation of Subsea Tree Flowline Based on Fluid-solid Coupling

针对水下采油树系统因检修或事故关停过程中,内部输油管道由于海水冷却作用易导致水合物沉积并堵塞通道从而影响水下油气田生产连续性的问题,建立了水下采油树内部输油管道流固耦合传热与保温的三维模型,定义了流固以及固固耦合边界面,并考虑了海水流动的影响,基于CFD流动与传热数值模拟,在稳态分析基础上,分别对无保温、25mm以及75mm保温层3种条件下的内部输油管道中的原油进行了瞬态分析,结果表明:无保温层条件下,原油经过8h冷却后几乎与海水温度相等;在外覆有25mm保温层时,原油可以在关停16h后保持温度高于水合物产生的临界温度;保温层越厚,保温效果越明显.

Hydrate will form and deposit to plug the channel in flowline to be a major concern of flow assurance in oil and gas production because of cooling down of sea water when subsea tree systems are shut down in normal or abnormal. Three-dimensional model for fluid-solid coupled heat transfer and insulation for flowline in subsea tree was built and interface of fluid-solid and solid-solid are given under considering the influence of sea water flow. After steady analyzing,based on CFD numerical simulation on fluid and heat transfer,transient analysis on inner pipe were done under the tree condition of lack of thermal insulation,25 mm thickness of insulation,75 mm thickness of insulation selectively. The results show that crude oil will be cooled down equally to temperature of sea water in 8hours in condition of lack of insulation,on the contrast,temperature will be up to the critical temperature for hydrate forming with 25 mm thickness of insulation and the effect of thermal insulation will be going better with thickness increasing of insulation.