An accurate prediction of the critical gas velocity for the liquid loading is of great importance for operators to select the tubing diameter for the newly drilled gas wells, or to optimize the production rate for production wells. It is clear from previous experimental studies of the liquid entrainment rate in the gas core that the liquid is mainly carried in the form of film under the critical condition of the liquid loading onset. It is more reasonable to establish a mathematical model based on the film reversal rather than based on the droplet reversal. In our previous paper entitled “Prediction of the critical gas velocity of liquid unloading in the horizontal gas well”, a new analytical model was established based on the force balance between the gas-liquid interfacial friction force and the bottom film gravity, but the model is not very convenient to use because of the complexity of calculating the average film thickness. In the present study, a new method is proposed to calculate the average film thickness from the bubble drift velocity in the mixture, so the new analytical model becomes much easier to use. The new analytical model is evaluated against 103 sets of experimental data, the data in 124 vertical gas wells and one horizontal gas well. Meanwhile, the effect of the liquid loading on the production of the horizontal gas well is also analyzed.

准确预测液体加载的临界气速对于操作员为新钻气井选择油管直径或优化生产井的生产率具有重要意义。从先前对气核中液体夹带率的实验研究可以清楚地看出，在液体加载开始的临界条件下，液体主要以薄膜的形式被携带。建立基于薄膜反转而不是基于液滴反转的数学模型更合理。在我们之前题为“水平气井卸液临界气速预测”的论文中，基于气液界面摩擦力与底膜重力之间的力平衡，建立了一种新的分析模型，但由于计算平均膜厚的复杂性，该模型使用起来不是很方便。在本研究中，提出了一种根据混合物中气泡漂移速度计算平均膜厚的新方法，因此新的分析模型变得更容易使用。新的分析模型根据 103 组实验数据进行了评估，这些数据来自 124 口垂直气井和 1 口水平气井。同时，还分析了载液量对水平气井产量的影响。新的分析模型根据 103 组实验数据进行了评估，这些数据来自 124 口垂直气井和 1 口水平气井。同时，还分析了载液量对水平气井产量的影响。新的分析模型根据 103 组实验数据进行了评估，这些数据来自 124 口垂直气井和 1 口水平气井。同时，还分析了载液量对水平气井产量的影响。