Experimental Investigation of Dynamic Adsorption–Desorption of New Nonionic Surfactant on Carbonate Rock: Application to Enhanced Oil Recovery

Abstract

Surfactants have the potential to reduce the interfacial tension between oil and water and mobilize the residual oil. An important process which makes the surfactant injection to be less effective is loss of surfactant to porous medium during surfactant flooding. This study highlights the results of a laboratory study on dynamic adsorption and desorption of Trigoonella foenum-graceum (TFG) as a new nonionic surfactant. The experiments were carried out at confining pressure of 3000 psi and temperature of 50 °C. Surfactant solutions were continuously injected into the core plug at an injection rate of 0.5 mL/min until the effluent concentration was the same as initial surfactant concentration. The surfactant injection was followed by distilled water injection until the effluent surfactant concentration was reduced to zero. The effluent concentrations of surfactant were measured by conductivity technique. Results showed that the adsorption of surfactant is characterized by a short period of rapid adsorption, followed by a long period of slower adsorption, and also, desorption process is characterized by a short, rapid desorption period followed by a longer, slow desorption period. The experimental adsorption and desorption data were modeled by four well-known models (pseudo-first-order, pseudo-second-order, intraparticle diffusion, and Elovich models). The correlation coefficient of models revealed that the pseudo-second-order model predicted the experimental data with an acceptable accuracy.