A Successful Foam Assisted Gas Lift Trial in a Matured Niger Delta Field

In the oil and gas business, continuous production optimization and enhancement is key for optimal field management. As a field depletes, water cut increases and oil rates decline. To maintain production, there is need to deploy artificial lift systems. The onshore FENE field is a matured Niger Delta field that has been in production for over 50 years. The field has wells that produces on natural flow and on gas lift. To improve field production, often requires optimization of the limited lift gas available to the gas lifted wells. Foam Assisted gas lift (FAGL) technology involves the downhole injection of a liquid foamer to lighten the fluid column and reduce slippage, thus improving well vertical lift performance. The foamer can be delivered downhole via a pre-installed downhole chemical injection line where available or into a lift gas stream on surface. The application is expected to increase oil production and / or decrease gas lift requirement. In Nigeria, a field trial was successfully carried out on two wells (Well-X and Well-Y) with water cuts greater than 60% in the onshore FENE field. The foaming agent was injected along with the lift gas via the A annulus of the wells. The field trial resulted in 280 bopd incremental net oil gain and a cumulative gain of 2510 bbls of oil for well-X and 120 bopd net oil gain and a cumulative gain of 832 bbls of oil for well-Y over the trial period of 9 and 7 days for well-X and well-Y respectively. There was also a significant reduction of water cut from an average of 76% to 66% and an estimated 25 - 35% savings in lift gas consumption. This paper details the candidate wells selection criteria, modelling details, foamers qualification, trial execution and post treatment results.