Abstract

Coreflooding experiments on aged Berea sandstone cores were performed to study the effect of divalent cations on the low-salinity-surfactant enhanced oil recovery (EOR). In the experiments where the core samples were aged for 4 weeks, replacement of a small amount of sodium with calcium in the injected low-salinity surfactant did not lead to higher tertiary recovery. However, the effects on wettability alteration and relative permeabilities were substantial. For the experiments with longer aging duration of 7 weeks, addition of calcium to the injected low salinity surfactant led to better oil recovery and the impact on wettability alteration was strong. Further addition of calcium led to lower oil recovery. Results of the injection experiments were discussed based on interfacial tension (IFT), surfactant adsorption, end-point relative permeabilities, and contact angles. A part of discussion was also dedicated to the effect of calcium on the secondary low-salinity water (LSW) injection. Although the oil re...

Talk to us

Join us for a 30 min session where you can share your feedback and ask us any queries you have

Schedule a call

Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.