Novel Surfactant Delivery System for Controlling Surfactant Adsorption onto Solid Surfaces. Part III: Oil Displacement Tests

Surfactant adsorption onto porous media is a significant problem during surfactant flooding in enhanced oil recovery (EOR). As the surfactant solution flows through the oil formation, surfactant concentration in the solution decreases due to adsorption onto the rock surface before the solution reaches the target residual oil saturation zones, rendering the process uneconomical. This paper validates an innovative technological solution to reduce surfactant adsorption onto the reservoir rock by using a surfactant delivery system based on surfactant complexations with β-cyclodextrin, which releases the surfactant at the target areas within the formation. This study evaluates the performance of this surfactant carrier system in recovering oil through sandpack surfactant flooding displacement tests conducted at simulated reservoir conditions. The experimental results demonstrate that the use of the surfactant delivery system consistently renders higher incremental oil recoveries (up to 73 %) when compared with the oil recovery obtained by conventional surfactant flooding. Therefore, this novel surfactant carrier system is highly effective at reducing surfactant adsorption onto rock formations, which facilitates the propagation and release of the surfactant at the oil saturation zones. This technology has great potential for EOR chemical flooding applications.