油井地面集输管停掺水温降数值模拟

掺水混输不加热集油工艺正不断发展完善,集输管停掺水温降过程是指导该技术实施的重要依据,掌握其降温规律对确定安全停掺水时间、再掺水启动方案和停掺水检修安排都有着十分重要的意义。基于计算流体动力学理论,利用FLUENT对油井地面集输管道停掺水后的温降过程进行数值模拟,得出不同含水率与不同初始油温下管内油品的温降曲线。根据管轴中心温降曲线可将整个降温过程分为3个阶段,第一阶段温降速度最快,其余两阶段较慢,第一阶段自然对流作用占主导地位,第二阶段管壁油品开始凝结,自然对流逐渐消失,第三阶段传热方式仅剩导热,且作用较弱,整个管内油品的凝结时间长短与停掺水初始油温及管内液体的含水率有关。通过模拟计算可得详细的温降过程,为实际停掺水不加热集油工艺设计提供参考依据。

Numerical Simulation of Gathering Pipeline Temperature Drop after Stoppage Mixing with Water

The technology of mixed transportation of oils mixed with water instead of heating is developing.The temperature drop process after stoppage of mixing with water is an important factor for implementation of this technology.Control of the regular pattern of the temperature drop process is important for confirming the fixing of safe stopping time,for a restart of the mixing scheme and for making a maintenance plan after the mixing with water is stopped.Based on the computation fluid dynamics theory,the temperature drop process was simulated by FLUENT.Then the curves of temperature drop in different moisture contents and different initial oil temperatures were obtained.According to the curve of temperature drop in the center,the colling process could be divided into three stages.The temperature dropped fast in the first stage.Natural convection played the dominant role in this stage.Oil begun to coagulate in the second stage,and natural convection was disappearing.Heat conduction was the only heat transfer mode in the third stage,presenting a feeble function.The time of coagulation related with the moisture content and the initial oil temperature.By simulation,some references could be provided to the design in practice.