Paper Title
Colloid Gas Aphron (CGA) for Enhanced Oil Recovery Applications

Abstract
Colloidal gas aphrons (CGAs)are dispersed microbubbles in an aqueous surfactant solution. When introduced into an aqueous system, CGAs undergo variation in sizes and numbers with time due to coalescence and/or creaming. This study examines the basic properties of CGAs that are relevant to their applications in enhanced oil recovery (EOR).CGAs with their unique characters offer some advantages that can be utilized in the EOR application.CO2 microbubbles have recently been used in enhanced oil recovery for blocking the high permeability zone in heterogeneous reservoirs. Microbubbles are colloidal gas aphrons stabilized by thick shells of polymer and surfactant. The stability of CO2 microbubbles plays an important role in improving the performance of enhanced oil recovery. In this study, a comprehensive experimental study was conducted to choose the appropriate formulation for CGA-based fluid with varying concentration of polymer to find the optimum concentration. Static stability tests, rheological behavior, and wettability test of CGAs were also performed. Comparative study on stability at different temperatures between CGA fluid with CO2 foam and CGA with air were also performed. Polyacrylamide polymer and at different concentration was used was used to find the optimum polymer concentration for CGA generation and a non-ionic surfactant TritonX-100 of 0.3 wt % was used. Further, the viscosity profile graph of CGA and base fluid was obtained and it clearly shows that the fluid has a shear thinning behavior which means that the fluid is easily pumpable for EOR process. Keywords - Colloid Gas Aphrons (CGA), Enhanced Oil Recovery (EOR), CO2 Microbubbles, Stability Tests, Rheological Behavior, Wettability.