Study On The Performance Of Polymer-enhanced Air Foam IOR Systems

Air flooding has been used for improving oil recovery from low permeability reservoirs for decades mainly because of its low cost and easy injectivity.However,it faces a challenge of gas channeling.This has been solved by the introduction of air foam flooding.The performance of air foam flooding has been studied by many researchers in china and abroad.Foam stability is one of the challenges faced by this foam.This research utilized polymer to create a stable air foam which will greatly improve oil recovery compared to the conventional air foam.The performance of the polymer-enhanced air foam is researched in this work.Polymer-enhanced air foam was made by using a zwitterionic surfactant BS-12,polymer HPAM and air.The concentration of the surfactant solution and polymer were selected through a series of Bulk foam tests which were performed in the laboratory.Isothermal flooding experiments were carried out to assess the performance of polymer-enhanced air foam at various temperatures and the recovery information noted.The results from the laboratory were simulated using CMG STARS simulator and experimental and simulated results were matched using a one-dimensional model.The perfect match was obtained and the model was scaled up to three-dimensional model which was used to carry out the various sensitivity analyses to assess the performance of polymer-enhanced air foam.This research work shows that the addition of polymer to a surfactant solution greatly enhances the stability of air foam which in turn improves the oil recovery.Oil recovery factor when Polymer-Enhanced Air Foam was used was 2.98% higher than in conventional Air Foam Flooding.The conformance control and blocking mechanism of air foam were greatly improved which lowered the water cut and increased the oil recovery.Polymer-Enhanced Air Foam flooding can be accurately modelled mechanistically using CMG.Gas-Liquid Ratio of 1:1 was found to be the most effective with small alternating slugs of 3 months.PolymerEnhanced Air Foam Flooding can be applied in any sedimentary sequence(Normal or Reverse).Further research is needed to fully understand the impact of polymer addition on the performance of not just air foam but also other foam systems like Nitrogen and Carbondioxide.