输油管线停待产期间气固液三相流中沙粒沉积规律的数值模拟研究

Numerical Simulation of Sand Deposition in Gas-Liquid-Solid Flow during Oilfield Pipeline's Shutdown or Pendent Period

以苏丹油田Palouge油区的输油管线参数为研究对象,基于多相流混合模型,采用Fluent软件对停待产期间输油管线内气液固三相流中沙粒的沉积规律进行数值模拟,研究稳态速度(v=0.9m/s)和速度线性减小(v=0.9-0.1t,v=0.9-0.05t)时沙粒的沉积规律。结果表明:沙粒在输油管线内的沉积速度逐渐增大,稳态速度时沉积速度存在极小值和最大值,沉沙量出现两个极大值,经过平稳过渡段后达最小值。速度线性减小时,沉积速度在靠近出口端局部降低,沉沙量主要由平稳段、减少段和增加段组成。随速度的减小,沉沙量起始减少位置和管线末端沙粒沉积速度逐渐减小,含沙量极小值和10m位置处含沙量均在t=2s时增至临界值。速度变化率对沙粒的沉积规律影响较小。

By taking the parameter of the oilfield pipeline in Sultan＇ s Palouge oildom as the research object, the sand deposition process in gas-liquid-solid flow during the pipelines＇ shutdown or pendent period was numerically simulated with Fluent software based on the mixture model for muhiphase flow; and the effects of steady velocity （v =0.9m/s） and decreasing linearly velocity （v =0.9 -0. It, v =0.9 -0.0St） on sand deposition were studied. The results show that the sand deposition rate within oilfield pipeline becomes increased gradually, and both maximum and minimum sand deposition velocity can be found if a steady speed can be kept; and the sand deposition value has two maxima, and then it reaches to a minimum value after a smooth transition section. When the velocity becomes decreased linearly, the deposition rate can locally reduce near the outlet. The sand deposition volume is mainly composed of stable, reducing and increasing stages. As the velocity becomes decreased, the starting reduction position and sand deposition velocity within the end of the pipelines decrease＇gradually, and the minimum sand content and the sand content at 10m position can increase to a critical value （when t =2s）. The velocity variation has a little effect on the sand deposition.