Investigation of the impact of multivalent anions on smart waterflooding in carbonate reservoirs

  • Weiwei Meng

    Student thesis: Master's Thesis


    Smart waterflooding is an emerging and one of the most economic and environmentally safe enhanced oil recovery techniques. Smart waterflooding helps to improve oil recovery by lowering the salinity and/or controlling ion composition of the injected water. It is a promising candidate EOR technique for tight carbonate reservoirs. A brief history of the development of this technique was reviewed. Smart waterflooding effect was first investigated in sandstones, and then it was introduced to carbonates. Both lab experiments and field pilot tests by various researchers were summarized and analyzed. A series of experiments were performed to investigate the effect of both the salinity and multivalent anion composition of the injection water on waterflooding. Contact angle measurement were employed as the screening technique to find the most promising smart brines from the designed candidates. Brines showed stronger effect of wettability alteration were selected to examine their ability to mobilize oil through coreflooding experiments. Concerning about potential formation damage by the precipitation of insoluble salts due to the incompatibility of injection water and formation water, compatibility tests in core plugs were performed for the screened brines before coreflooding experiments. IFT and zeta potential tests were also performed aiming to provide more information on the smart water effect. Brines spiked with multivalent anions generally exhibited more noticeable ability to alter wettability of the core samples, comparing to the origin or diluted brines without addition of ions. Lower IFT values and a shift of the zeta potential from highly negative to less negative were also observed for the brines gave better contact angle results. The positive effect of the brines in wettability alteration was confirmed by the 4.9% ~ 8.3% incremental oil recovery in sequential injection of smart brines in coreflooding experiments.
    Date of Award2015
    Original languageAmerican English
    SupervisorMohamed Haroun (Supervisor)


    • Applied sciences
    • Hmp swf in carbonate reservoirs
    • Multivalent ion management eor
    • Petroleum engineering
    • Po4 swf in carbonate reservoirs
    • Smart waterflooding
    • 0765:Petroleum engineering

    Cite this