Transport Mechanisms of Xanthan Biopolymer Solutions in Porous Media

Abstract

ABSTRACT The propagation of a polymer slug through porous media is affected by several transport mechanisms including polymer adsorption, inaccessible pore volume, and dispersion. In many previous studies, a specific mechanism (e.g. adsorption) is evaluated, but few studies attempt to evaluate all three mechanisms under a consistent set of flooding conditions. In this paper, a comprehensive study was conducted to evaluate the simultaneous effects of these three mechanisms for single-phase Xanthan biopolymer core floods at 100% brine and at residual oil. The polymer concentration was systematically varied in these floods. The effects of inaccessible pore volume were also investigated in a two-phase Xanthan biopolymer flooding experiment in an initial oil-saturated core. Several key trends on the effects of polymer concentration and residual oil for these polymer transport mechanisms were noted. Attempts are then made to rationalize these trends in terms of microscopic (i.e. molecular and pore level) effects.