Liquid loading is a phenomenon in which liquid accumulates in the wellbore of mature gas wells, causing a significant reduction in production and sometimes permanent well abandonment. This paper introduces a new model for predicting liquid loading onset, based on the reversal of a non-uniform liquid film. The momentum balance equation for annular flow is, in the proposed model, expressed as a function of liquid holdup instead of liquid thickness. The model employs auxiliary correlations to obtain liquid holdup and an interfacial friction factor, developed from literature data.

The accuracy of the proposed model is quantified by comparing laboratory data from this work and field datasets from previous studies, with the predictions of existing models. The proposed model successfully reproduces the experimental data and field data, and gives the highest prediction accuracy and the lowest average error when compared with existing models. The proposed model therefore represents a significant improvement on existing models.

The applicability of auxiliary correlations means that this model should be restricted to upward pipe inclinations of 30°–90° from the horizontal, liquid viscosities of 1.1 cP and 0.018 cP, and superficial velocities of gas of 3–60 m/s and of liquid of 0.01–0.2 m/s. Results show that the model exhibits poor performance when applied to pipe inclinations lower than 30° from the horizontal.

液体装载是一种现象，其中液体积聚在成熟气井的井眼中，导致产量显着下降，有时甚至永久性弃井。本文介绍了一种基于不均匀液膜反转的预测液体加载开始的新模型。在所提出的模型中，环形流动的动量平衡方程表示为液体滞留量而不是液体厚度的函数。该模型利用辅助相关性来获得液体滞留率和界面摩擦系数，这是根据文献数据得出的。

通过比较这项工作的实验室数据和先前研究的田间数据集，以及现有模型的预测，可以对所提出模型的准确性进行量化。与现有模型相比，所提出的模型成功地再现了实验数据和现场数据，并给出了最高的预测精度和最低的平均误差。因此，所提出的模型代表了对现有模型的重大改进。

辅助相关性的适用性意味着该模型应限于水平的管道向上倾斜角度为30°–90°，液体粘度为1.1 cP和0.018 cP，气体的表观速度为3–60 m / s和液体0.01-0.2 m / s。结果表明，该模型在应用于与水平面成30度以下的倾斜角度时，表现出较差的性能。