高液气比气井临界携液流量计算方法

Calculation method of critical liquid-carrying flow rate of high liquid-gas ratio gas well

张德政 王志彬 于志刚 张瑞金 杨波

中海石油（中国）有限公司湛江分公司，广东 湛江 524057 西南石油大学油气藏地质及开发工程国家重点实验室，四川 成都 610500

Zhanjiang Branch of CNOOC Ltd., Zhanjiang 524057, China State Key Laboratory of Oil and Gas Reservoir Geology and Exploitation, Southwest Petroleum University, Chengdu 610500, China

高液气比气井环状流场中的液相主要以液膜形式被携带，从液膜逆流角度建立气井携液模型比从液滴回落角度建立更为合理，因此研究了倾斜管低边液膜厚度、平均液膜厚度和气液界面摩擦因数的计算方法。基于液膜受力平衡和动量守恒，建立了适用于不同井型（直井、定向井、水平井）的液膜携带机理模型，得到了临界携液流量的理论计算方法；基于机理模型宽范围计算结果，建立了类似Belfroid模型的经验关系式。Belfroid模型中经验系数为常数，而文中提出的经验系数随管径增大而增大，随液相表观流速增大先增加后减小，随温度增加而减小。根据南海西部产水气井实例验算，积液预测准确率达100%，说明该方法具有较高的预测精度，可为海上和陆地气井积液预测提供理论支撑。

 Liquid in the annular flow field of high liquid-gas ratio gas well is mainly carried in the form of liquid film. It is more reasonable to establish a liquid-carrying model based on the reverse flow of liquid film in the wellbore than on the liquid drop. Therefore, the calculation methods of liquid film thickness in the low-side of the inclined pipe, average liquid film thickness and gas-liquid interfacial friction coefficient were studied. Based on the stress balance and the momentum conservation of the liquid film, a liquid film carrying mechanism model suitable for different well types(vertical well, directional well and horizontal well) was established, and the theoretical calculation method of critical liquid?鄄carrying flow rate was obtained. Based on the wide range calculation results of the mechanism model, an empirical relation similar to the Belfroid model was established. The empirical coefficient in the Belfroid model is constant, while the empirical coefficient proposed in this study increases with the increase of pipe diameter, increases first and then decreases with the increase of liquid apparent velocity, and then decreases with the increase of temperature. According to the examples of water?鄄producing gas well in western South China Sea, the prediction accuracy of liquid loading was 100%. It shows that this method has high prediction accuracy and can provide theoretical support for the prediction of liquid loading in offshore and onshore gas wells.

10.6056/dkyqt202203021