The Effect of Water-Soluble Compounds of Acidic Crude Oil on Surface and Inter facial Tension in Low Salinity Water Injection

In this study, the effect of water-soluble amphiphilic compounds of crude oil and ionic composition of water, on surface and interfacial tension were investigated. Distilled water and salt water of NaCl and Na2SO4 in five ionic strengths up to 2 molar were contacted to the crude oil to be saturated with crude oil amphiphilic compounds. The effect of these compounds on water properties are examined with pH, total organic carbon (TOC), surface tension and interfacial tension tests. Finally, the obtained results show that a low amount of acidic and basic compounds of crude oil were dissolved in contacted waters which have significant effect on surface and interfacial tension. In addition, the results reveal that by increasing the ionic strength of NaCl and Na2SO4 salt water, there is optimal salinity between 0.1 and 0.25 molar.