Factors influencing interfacial electric properties of produced water from oilfield

Key words:  zeta potential  petroleum sulfonate  HPAM  clay particle  oil-mineral aggregates (OMA)

Abstract:

Hie effects of HPAM, petroleum sulfonate，ion strength，clay particle and their complex systems on the oil-water interfacial electric properties of Gudong 4# crude oil from Shengli Oilfield were investigated on in-house lab setup. The results show that within the certain range of concentration, HPAM as well as petroleum sulfonate can make the zeta potential of oil drops increase.When their concentrations are hi^i，the zeta potential of oil drops will not change much with the concentrations increasing- TTie zeta potential of the oil-mineral aggregates (OMA) formed by clay and oil droplets is higher than that of particles existing in any system with single factor. The zeta potential of OMA existing in suspensions containing HPAM is higher than that of particles in corresponding systems without HPAM，but their change laws are similar. In the complex system containing petroleum sulphonate，the zeta potential of OMA is higher than that of oil droplets and clay particles which separately exist in the emulsions only containing petroleum sulfonate or the suspensions containing clay particles when the concentration of petroleum sulfonate is low. However, the zeta potentials of the above OMA and the oil droplets are gradually near when the concentration of petroleum sulfonate is high. Tlie zeta potential of OMA existing in the more complex system containing HPAM，petroleum sulfonate and clay particles is higher than that of particles existing in any system with singje factor. And the adsorptiop behaviors of the components on the surface of the particles are influenced by each other under certain conditions. But there are no remarkable synergetic effects among the factors in the aspect of the influence of interfacial electric properties for the oil-water interface.