基于CFD-DEM耦合方法的水合物堵塞模拟

Hydrate blockage simulation based on CFD-DEM coupling method

深海油气在生产运输过程中涉及高压、低温条件,极易产生水合物并导致管道堵塞。为了探究含有水合物颗粒流体的堵管现象以及颗粒随连续相运动的规律,采用CFD-DEM(计算流体力学离散单元法)耦合的数值模拟方法,结合商业软件Fluent和EDEM,考虑水合物颗粒间聚并、颗粒与管壁之间的粘附作用,建立三维含水合物的固液管道模型,使用节流元件模拟在实际生产中水合物黏结在管壁上减小流通面积的情况,分析不同流速和不同孔径比下的流动状态。由此,界定了水合物颗粒节流管路的堵塞标准,得到不同流速下保证管路流动性的最小孔径比,为水合物堵管风险研究提供参考。

In the high pressure and low temperature conditions during production and transportation of subsea oil and gas,hydrate is formed easily,which could cause the risk of pipeline blockage.To investigate the phenomenon of pipeline blockage of fluid containing hydrate particles and the mechanism of particle flow with the continuous phase,a threedimensional hydrate-contained solid-liquid pipeline model was established with the numerical simulation method based on CFD-DEM(Computational Fluid Dynamics-Discrete Element Method)coupling combined with the commercial software Fluent and EDEM,giving consideration to the agglomeration of hydrate particles and the adhesion of particles on pipe wall.The condition that hydrate deposition on the pipe wall reduces the flow area during actual production was simulated using a throttling element,and the flow state was analyzed at different velocity and aperture ratio.Thereby,the critical state of blockage was defined for hydrate particle throttling pipeline,and the minimum aperture ratio of pipeline at different flow rate was obtained,which provide a reference for the study on the risk of hydrate blockage.