Nonionic Surfactant for Enhanced Oil Recovery from Carbonates: Adsorption Kinetics and Equilibrium

Around 40% of the current world conventional oil production comes from carbonate reservoirs, dominantly mature and declining giant oilfields. Tertiary oil production methods as part of an Enhanced Oil Recovery (EOR) scheme are inevitable after primary and secondary oil production. The goal of surfactant flooding is to reduce the mobility ratio by lowering the interfacial tension between oil and water and mobilizing the residual oil. This paper highlights adsorption kinetics and equilibrium of Glycyrrhiza Glabra, a novel surfactant, in aqueous solutions for EOR and reservoir stimulation purposes. A conductivity technique was used to assess adsorption of the surfactant in the aqueous phase. Batch experimental runs were also performed at various temperatures to understand the effect of adsorbate dose on the sorption efficiency. The adsorption kinetics was experimentally investigated at room temperature (27 degrees C) by monitoring the uptake of the Glycyrrhiza Glabra as a function of time. The adsorption data were examined using different adsorption equilibrium and kinetic models. The Langmuir isotherm suits the equilibrium data very well. A pseudo-second order kinetic model can satisfactorily estimate the kinetics of the surfactant adsorption on carbonates. Results obtained from this research can help in selecting appropriate surfactants for design of EOR schemes and reservoir stimulation plans for carbonate reservoirs.