A new chemical enhanced oil recovery method?

Abstract

The efficiency of alkali-surfactant-polymer (ASP) flooding for enhanced oil recovery (EOR) can be muchless than expected under various reservoir conditions that include low permeability, high temperature,high formation brine salinity and the presence of divalent cations (Ca+2, Mg+2) in the formation brine. Thisis due to polymer degradation and low injectivity, alkali precipitation and scaling in the well and surfaceequipment. Moreover, polymers substantially reduce the capability of treatment of produced water tobe used for re-injection, upcycling or discharge.This paper reports on an experimental study of new chemical EOR approach that has the potential toovercome the above drawbacks. The new chemical formulation consists of the combination of a non-polymeric viscosity enhancement compound and a blend of two surfactants. The performance of thischemical formulation was evaluated by a series of coreflood tests on Bentheimer sandstone cores, understable gravity conditions, with the aid of X-ray Computed Tomography. A significant reduction in theresidual oil saturation was observed by constructing the capillary desaturation curves (CDC), suggestingthat the proposed formulation is potentially a good chemical EOR agent.