倾斜井筒气液两相流的模型化方法

Mechanistic modeling of two-phase flow in deviated wells

倾斜井筒气液两相流动是井筒举升方式优选和生产优化的基础,也是长期以来在理论上没有得到很好解决的一个问题,不能简单采用垂直井筒加修正系数的方法处理。分析国内外研究现状,认为倾斜井筒气液两相流动的流型应分为泡状流、分散泡流、段塞流、搅动流、环流和雾流,综合前人成果给出了各流型在倾斜井筒的存在条件。提出了雾流的特点及其转变机理、泡状流的新管径条件以及段塞流、雾流压降新的计算方法。通过某油田28口油井35井次的井底流压计算结果的应用表明,绝对平均相对误差7.093%,与计算斜井压降的常用的Beggs-Brill和Ansari模型相比,误差较小,能够满足工程计算的需要,且不存在半经验模型的收敛性和区域性的问题。所建立的倾斜井筒气液两相流动模型具有应用价值。

Gas-liquid two phase flow in deviated wellbore is the foundation of choosing ways of oil pumping and production optimization and it can be resolved well by simply adding an efficiency to the vertical well model. It is also a problem which has not been solved completely in theory for a long time. All the flow patterns in the deviated wellbore were described as bubbly, dispersed bubble, slug, chum, annular and mist flows according to the analysis of the studies published. Mist flow predicting model was developed and flow-pattern map was obtained. Pipe diameter condition prediction in bubbly flow, new methods of predicting pressure drop of slug flow and mist flow were included. The entrainment fraction in annular space was also defined. 35 groups of field data of 28 wells were used to validate the models. Results show that the absolute average percentage error is 7.093%, which is almost the same with that of Beggs-Brill and Ansari methods. It is of benefits of no convergence and high adaptability.