A simplified transient model to predict liquid loading in gas wells

This paper presents a transient model to predict liquid loading in gas wells. This models enables the estimation of erratic or cease of production due to liquid loading using a simple but robust technique. This approach is supported by experimental and field data. The model described in this paper proposes the use of the so-called "nodal analysis technique" to predict liquid loading in gas wells. The approach proposed modifies the tubing performance relationship instead of using the common critical velocity concept. This modification enables the simple use of nodal analysis to accurately predict liquid loading initiation, including the amount of time require to reach this condition. The model shows good agreement with experimental and field data on the prediction of liquid loading. From the modeling results and comparison with field and experimental data, it possible to conclude that this model can provide a reasonable prediction of the liquid loading phenomena. For instance, one of the main objectives of using models to predict liquid loading is to anticipate when a gas well would start suffering from liquid loading problems, and potentially stop flowing. The use of conventional models showed a significant mismatch in the critical flow for liquid loading when compared to field data, while the use of the model proposed would reduce this mismatch significantly. In addition to that, the use of this simplified model also enables understanding of the main field symptoms related to liquid loading in gas wells.