Effect of Viscosity of Alkaline/Surfactant/Polymer on Enhanced Oil Recovery in Heterogeneous Sands

Abstract

Abstract New development in technology and the rise in world oil prices give promises that substantial portion of otherwise neglected oil can be recovered. Reservoir heterogeneity significantly affects both the oil production and the performance of injection wells in water flooding or miscible flooding projects, thus the influence of heterogeneity on the oil exploitation process has been a concern in petroleum engineering. Numerous laboratory experimental studies and field tests on Alkaline/Surfactant/Polymer (ASP) flooding have been done. In this research, the relationship between the viscosity of an ASP solution and oil recovery in heterogeneous porous models were studied. Twenty-four ASP flood tests were conducted using artificial models. These models were made to have different permeability variation coefficients so that ASP floods in homogeneous and heterogeneous reservoir can be compared Local materials in place of industrial materials were used. Four ASP solutions were prepared and used in the ASP flood tests. The effect on tertiary oil recovery as viscosity increased was investigated. For heterogeneous models, it was found that increasing the ASP viscosity from 1.00cp to about 2.56cp increased and improved oil recovery. Further increase in viscosity to about 3.6cp had no much effect on recovery, because increasing the alkaline concentration reduced the visco-elastic effect of the viscosity of the solution.