Smart-Water EOR Made Smarter A Laboratory Development Available to Purchase

Smart Water and Low Salinity EOR is established as a techno-economically promising method through laboratory coreflood studies and single well tracer studies in field pilot cases. The method is based on lowering salinity of injected water and spiking of multivalent ions such as Mg²⁺, SO₄²⁻, PO₄³⁻ ions. Wettability alteration and expansion of electrical double layer are attributed to the trapped oil release mechanism. This however invites the possibilities of induced and aggravated scale deposition if the formation water is rich in divalent cations (as in the case of carbonate formation). The resulting formation damage and reduced well productivity may negate the advantages of smart waterflood. This article presents the outcome of an extensive study, conducted to optimize smart water composition targeting an offshore carbonate reservoir. After quantifying the scaling potential at reservoir condition, a Polyphosphate compound is introduced which arrested the scale precipitation. Through contact angle, interfacial tension, Zeta-potential and drainage studies it is established that new formulation not only has reduced scaling potential but also enhanced ability for oil recovery.