A New Model For Predicting Liquid Loading In Multiphase Gas Wells

ABSTRACT

Liquid column that accumulates in the wellbore leading to the reduction or completely preventing the production of gas well is called liquid loading. This is one phenomenon that is essential because in other to optimize the recovery of hydrocarbon from the gas reservoir and to prevent the occurrence of liquid loading, pressure differential as a function of flow rate across the valves must not be neglected. Several options have been employed in well completions to predict liquid loading and how it can be mitigated but the results have shown varying degrees of discrepancies and hence cannot be easily used because of the challenges involved in predicting the bottomhole pressure in a multiphase flow. In the last decades, different techniques and correlations have been offered by many authors for determination of critical liquid loading rate. This new model considered the pressure drop at the bottomhole and along the functional nodes (valves). The model is an improvement on Fadiro model with the introduction of valve equation to the fundamental momentum equation. It described a systematic approach for estimating liquid loading in a gas well by numerical integration method. None of the previously described models considered pressure drop along the functional node. It is therefore, evidently effective when compared analytically with Turner, Guo and Fadairo models. The result shows that the flow rate during the transient stage is faster than that of Fadairo and it became stable at a certain time during production. It was also observed that the minimum energy required to lift liquid out of the wellbore is higher than that at the initial production stage. The numbers of incorrectly predicted wells as calculated by the new model are far lower than all the previously described models. This model is essential for field operators so as to equip them on how to tackle the risk of liquid loading during natural gas production.