Multi-component Ion Exchange (MIE) was proved to be a major mechanism occurred during Low Salinity Waterflooding (LSWF). Reduction of both total salinity and concentration of divalent ions of injected water together with a presence of monovalent ion results in dissolution of divalent ions linking between rock surface and oil. As a consequence, oil is liberated from rock surface.
This study aims to study effects of monovalent ions in MIE mechanism. Stirring test is�performed and results�show that ion with less�hydration radius�tends to be more active in MIE;�hence, potassium ion and cesium ion illustrate potential in oil recovery mechanism.�Then, the best three water formulations can be selected to perform imbibition and coreflood tests and both tests show results in the same direction. Pure cesium ion�is very fast in MIE mechanism while pure potassium ion�with a few water molecules can also function well in oil recovery. However, its mobility is less than cesium ion. The combination of cesium-sodium-calcium at 20-40-40�tends to be similar results of�pure potassium ion. In comparision, Pure cesium ion�is the best water formulation enhacing recovery factor�up to 0.26. However,�complexometric titration result�shows remarkable contrast to the stirring test that both cesium ion and potassium ion tend to displace magnesium ion better than calcium ion. In conslusion,�this study has already proved the theory regarding the hydrate of monovalent ion.