Liquid loading is a serious problem in areas where gas fields are maturing. An analysis is provided of the production behaviour over time of liquid-loaded wells. This shows clearly that these wells can operate at two different rates, a stable rate at which full production is taking place and a lower metastable rate at which liquid loading effects play a role.

A model has been constructed which enhances the understanding of the process of water build up and drainage in gas wells. It assumes a single gas and water co-production point and a single water re-injection point. As expected a water column is built up in the well as soon as production takes place below the critical rate. As observed in the field, for good inflow performance a metastable flowrate can be observed. At this state the water re-injection and water coproduction rate are equal to one another and the water column height stabilizes.

A sensitivity analysis has been carried out to determine how well parameters influence the metastable flowrate, the time required to reach this metastable rate, the corresponding water column height and the shut-in time required to drain this water column. The results of the analysis indicate that significant metastable flow rates occur in wells which have good inflow performance, a low water gas ratio and a large distance between injection and production point.

Furthermore a steady state analytical solution has been derived for the metastable rate and stabilized water column height confirming the numerical analysis results.

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