Modelling Sweep Efficiency Improvement By In-Situ Foam Generation Using A Dispersed Surfactant In The Gas Phase

Abstract

Summary Foam in porous media is a proven method to improve the sweep efficiency of a Flooding fluid in EOR process and the effectiveness of a treatment fluid in well intervention procedures. Foams are often generated by SAG (Surfactant alternating gas) or co-injection methods, although these operations result in excellent incremental production, profit losses could be high due to high surfactant retention and lack of water injection facilities in some target oil fields. One way of reducing operational costs is by injecting surfactant disperse throughout the gas phase in a process called “Disperse Foam”. Core flooding experimental results have proven that disperse foam technique can reduce surfactant retention kinetics and increase cumulative oil production, Additionally, the injection upscaling from laboratory to field reduces significantly operational cost. Because few laboratory core tests and field pilots have been implemented using disperse foam technique, there is high uncertainty associated to this process. Moreover, literature models do not account for all the associated phenomena, including surfactant transfer between gas and liquid phases, and the lamellae stability at low water saturations. Hence, the development of a disperse foam mechanistic model is key to understand disperse foam operations phenomena. In this work, a mathematical model is developed, the model accounts for surfactant mass transference between gas and liquid phases in non-equilibrium using a particle interception model, dynamic surfactant adsorption on the rock surface with a first order kinetic model and foam kinetics using a population balance mechanistic model.