Study And Development Of Demulsifier Used For Demulsification Of Complex Foam Flooding Produced Liquid

The Polymer flooding being applied and the ASP flooding and complex foam flooding being test in Daqing Oilfield have resulted in EOR rates respective 12%, 20% and 30% over water flooding. However, residual alkaline, surfactants, polymer and natural gas in produced liquid have also resulted in tighter crude oil emulsion in produced liquid, leading to poorer oil/water separation of both produced liquid and oily water.In this work, the influences of stabilization and demulsification efficiency of artificial chemical flooding produced liquid in Daqing Oilfield were systematically studied on artificial chemical flooding produced liquid. Respective relation functions between water cut in oil and oil cut in oily water to their influencing factors were achieved. Demulsifier FD9808, that is compatible to complex foam flooding produced liquid were developed.Residual alkaline, surfactants, polymer and natural gas in produced liquid have resulted in tighter crude oil emulsion in produced liquid, leading to poorer oil/water separation of both produced liquid and oily water.The most significant influences in five factors of water cut, polyacrylamide content, surfactant content, alkaline content and natural gas content in artificial complex foam flooding produced liquid to stabilization of artificial complex foam flooding produced liquid are alkaline content and natural gas content. The more high alkaline content and natural gas content in artificial complex foam flooding produced liquid are, the more high water cut in oil and oil cut in oily water of artificial produced liquid after thermo-settlement are, namely, the more high stabilization of artificial produced liquid is.The most significant influences in five factors of water cut, polyacrylamide content, surfactant content, alkaline content and natural gas content in artificial complex foam flooding produced liquid to demulsification efficiency of artificial complex foam flooding produced liquid are surfactant content, alkaline content and natural gas content. The more high surfactant content in artificial complex foam flooding produced liquid is, the more high water cut in oil of artificial produced liquid after thermo-settlement is. The more high alkaline content and natural gas content in artificial complex foam flooding produced liquid are, the more high oil cut in oily water of artificial produced liquid after thermo-settlement is.Demulsifier FD9808 is compatible to complex foam flooding produced liquid, features higher demulsification efficiency and more comprehensive compatibility, can meet application requirements of complex foam flooding.