Design and performance analysis of a formulation based on SDBS and ionic liquid for EOR in carbonate reservoirs

A large proportion of extant crude oil is found in carbonate reservoirs worldwide. Alkylbenzene sulfonates are inexpensive anionic surfactants but they cannot be used these due to their incompatibility with divalent ions and high adsorption on the rocks. This paper proposes solution that problem by blending this kind surfactant surface-active ionic liquids. Namely, a formulation containing sodium dodecylbenzenesulfonate (SDBS) cocosalkylpentaethoximethylammonium methylsulfate ([C1EG][MeSO4]) was designed for application. Two optimal blends, at 40/60 73.7/26.3 SDBS/[C1EG][MeSO4] ratios, were synthetic seawater via equilibria interfacial tension (IFT) studies. Core-flooding tests carried out check performance both blends. The first blend ratio (40 wt% SDBS) selected define an (1 298.15 K) its better injectability, higher reduction IFT, lower adsorption, recovery. Attained tertiary recovery (18% original place), low (0.37 mgblend/grock), shows promising solution. main mechanism associated improved IFT reduction. work offers significant advance application natural petroleum reservoirs.