Experimental Investigation of Adsorption Densityby Batch Equilibrium Test onto Carbonate Cores

In chemical flooding, surfactants are inevitably adsorbed on the surface of reservoir rock by the rock/oil/brine interaction. The experimental study aimed to calculate adsorption densities andalso to model of the equilibria of adsorption processes on carbonate rocks by adsorption isotherms. The equilibrium adsorption was calculated by examining adsorption behavior in a system of a solid phase (carbonate rock) and an aqueous phase of surfactant with 5000 ppmsynthetic/field brine. The surfactant adsorption on reservoir carbonate rocks was measured to determine the amount of excess surfactant that must be added into the injection stream in the surfactant alternating CO2 injection tests.In this paper, surfactant adsorption densities weremeasuredby batch equilibrium test on crushed rock for different surfactant concentration. The range of initial surfactant concentrations were 500, 1000, 2000, and 5000 ppm in crushed coressystem. The applied commercial surfactant is Sodium Lauryl Sulphate (SLS) which is an anionicsurfactant. Finally, the Langmuir adsorption and the Freundlich isotherms were used to characterize the equilibria between the amount of adsorbate that accumulates on the adsorbentand the concentration of the dissolved adsorbate. 2For the crushed rock the necessary equilibrium time was approximately six hours. Also, the rateof adsorption is dependent on availability of surfactant in the system; It was found that the adsorption of surfactant increased with increasing surfactant concentration.

Keywords:

Surfactant Adsorption , Concentration , Adsorption Isotherm , Crushed Core