水平管分层流下微孔泄漏特性数值模拟和实验分析

在油气田开发过程中，通常采用气液相混输模式，管道受腐蚀等因素影响容易出现穿孔而发生两相流泄漏。为分析两相流泄漏特性，对管内常见流型分层流下的微孔泄漏特性进行数值和实验分析；采用VOF耦合Level set算法分析了不同影响因素下的气液两相泄漏特性，设计了1种管道泄漏收集装置，进行室内两相流泄漏实验，并验证了数值预测模型的准确性。研究结果表明:气液两相流经过管壁泄漏口时会发生相分离，泄漏特性受小孔方位、管路内外压差、气液相流速影响较大；泄漏口位于管路侧壁时的泄漏特性与其他角度下的泄漏特性有所不同，可用泄漏影响区内的气液分布进行解释；当泄漏口位于管路底部时，存在临界液相分流系数，当液相分流比小于此临界值时，泄漏流体为单相液体。VOF耦合Level set算法的数值方法可为管路泄漏量预测和相分离特性分析提供参考。

Numerical simulation and experimental analysis on leakage characteristics of micropore on horizontal pipe under stratified flow

The gas liquid mixed transportation has usually been adopted in the development process of oil and gas field, so the perforation of pipeline is easy to occur and causes the two phase flow leakage due to the effect of corrosion and other damage. In order to analyze the leakage characteristics of two phase flow, the numerical and experimental analysis were carried out on the leakage characteristics of micropore under the stratified flow as the common flow type in the pipeline. The gas liquid two phase leakage characteristics under different influence factors were analyzed by using VOF coupling level set algorithm. A pipeline leakage collecting device was designed to conduct the indoor two phase flow leakage experiments, and the accuracy of the numerical prediction model was verified. The results showed that the phase separation would occur when the gas liquid two phase flow passed through the leakage hole on the pipe wall, and the leakage characteristics were greatly affected by the hole location, pressure difference between inside and outside of the pipe, and the gas liquid phase flow velocity. The leakage characteristics when the leakage hole was on the side wall of pipe were different with those under other angles, which could be explained by the gas liquid distribution within the leakage influence region. When the leakage hole was located at the bottom of pipe, there existed a critical liquid phase extraction coefficient, and when the liquid phase extraction ratio was smaller than the critical value, the leakage fluid was the single phase liquid. The numerical method of VOF coupling level set algorithm provides the reference for the effective prediction of pipeline leakage quantity and phase separation characteristics.