Continuous Foam Injection is a proven deliquification technique in gas wells, but the technology typically struggles to perform in wells with high fractions of liquid hydrocarbons. For gas lifted oil wells operating at high water cuts however, continuous downhole foam injection may prove feasible to enhance production. A field trial to test this theory was successfully executed within an oil producing facility in The Netherlands. The objective of this trial was twofold: First, to observe the changes in production owing to downhole injection of a foaming agent while keeping the lift gas rate constant. Second, to perform a lift gas utilization test to identify potential lift gas savings with the assistance of foam. Furthermore, strict specifications on the export crude and produced water had to be achieved. The trial showed successful results. The well had a fast response to the addition of foam whereby initial sluggish production stabilized. This has overcome the flow instability related production deferment, which was significant. Further increases in the foam injection rate to reach the optimum foam concentration helped the well to produce up to 20% more gross liquid than the measured and calculated stable rates. The trial has revealed that with the application of foam, lift gas savings of 35% were feasible and more could be achieved depending on the desired gross liquid production. No process facility upsets were experienced during the trial.
This paper describes the detailed aspects of the trial, including the preparation, execution, and modelling techniques which will benefit and add to the current body of knowledge of foam lift to the petroleum industry.