Lignin as per flush reducing gemini surfactant adsorption on clay minerals

Abstract

In order to increase the oil recovery factor, enhanced oil recovery method has been used to exploit residual oil from the reservoirs. Chemical enhanced oil recovery is one of the proven useful techniques which include injection of surfactant to reduce the oil-water interfacial tension. Recently, the applicability of surfactant to tolerate high salinity and high temperature conditions has resulted in investigation of the new proposed surfactant called aerosol-OT. In this study, the role of clay mineral on aerosol-OT surfactant adsorption, the effect of mineralogical composition and clay mineral percentage on the surfactant adsorption and the effect of salinity and temperature on the adsorption quantity were investigated. Finally, the study examines the effectiveness of alkali lignin as a sacrificial agent for reducing aerosol- OT dynamic adsorption. The experiments were divided into three parts including static adsorption batch experiments, dynamic adsorption in sandpack flood and dynamic adsorption after preflush using alkali lignin. Results of static tests showed that aerosol-OT adsorbed on both sand and clay minerals. Increasing the clay percentage resulted in increase the adsorption, while the increases in temperature reduced the adsorption. The results of adsorption test revealed that the highest adsorption was on kaolinite while the adsorption on illite and montmorillonite surface was significant and should not be ignored. Meanwhile, the adsorption reached its highest value (21 g/kg) in salinity of 60,000 ppm sodium chloride at 25 °C. The dynamic adsorption results showed higher adsorption compared to the static adsorption under the same condition while the increasing trend order remained the same. The maximum adsorption at the dynamic condition was 44 g/kg at the 7% kaolinite sandpack. The alkali lignin was effective to reduce the aerosol-OT adsorption between 25% up to 65% during the dynamic flow. The findings of this study are useful to understand the aerosol-OT adsorption at the reservoir condition and the lignin efficiency as sacrificial agent in reducing aerosol-OT adsorption for further usage in chemical enhanced oil recovery application.