Research On Properties And Treatment Technology Of Weak Base ASP Flooding Produced Liquid

Weak base ASP flooding is a compound flooding technology which uses inorganic weak base instead of strong alkali.Compared with strong alkali flooding system with NaOH as alkaline agent,weak base ASP flooding produced liquid with Na2CO3 as alkaline agent has little corrosion,little scale formation and do less damage to reservoir which overcomes the disadvantages of strong base ASP flooding and then currently has been used in Daqing oil field.Weak base ASP flooding produced liquid remains a number of alkali,surface active agent and polymer,and then it is difficult to separate oil and water due to the serious emulsification of oil and water and the coexistence of many kinds of emulsions.The research on treatment technology of weak base ASP flooding produced liquid lays a theoretical foundation of oil-water separation process and choice of operating parameter which is very beneficial to the application of weak base ASP flooding in the oil field.This paper mainly uses the OMEC PIP 9.0 particle image analyzer to detect the emulsification degree of weak base ASP flooding emulsion.The dynamic interfacial tension tester is used to detect the dynamic interfacial tension at the oil-water interface of the weak base ASP flooding produced liquid.The DHR-2 interfacial rheometer measures the interfacial strength of weak base ASP flooding produced liquid.Zeta PALS potentiometer detects the electric double layer potential of produced liquid.BT-9300 H laser particle size distribution analyzer measures the suspended solid particle size and the oil particle size distribution in the sewage.A variety of different demulsifiers used to conduct preliminary screening for dehydration experiments,and then the demulsifiers with good dehydration effect were compared at different time,temperature and concentration to select the best demulsifier.990 conductivity meter measures the conductivity of the produced liquid.The IJJ-IIB crude oil dielectric strength automatic tester measures the breakdown field strength of sample wells at different times and different chemical agentsThrough the study,weak base ASP flooding produced liquid has serious emulsifying and the dispersion degree is very high.The average particle size of the stable internal phase particles is between 6.25?m and 7.44?m,which is more difficult to dehydrate the produced liquid than water flooding.The oil-water interfacial tension of the weak base ASP flooding produced liquid is generally between 0.01 mN/m and 1.5mN/m,and most of them are between0.1mN/m and 1mN/m.The elastic modulus and viscosity modulus of weak base ASP flooding produced liquid are n×10-2N/m,interfacial viscosity is within 0.012 mPa·s.The electricpotential absolute value of weak base ASP flooding produced liquid is between 30 mV and50 mV.The particle size of the suspended solids and the oil beads in the sewage increased with the increase of the temperature.The selection of demulsifiers under different active agents have been determined.The measured value of the conductivity is approximately between3×103 ?s/cm and 2×104 ?s/cm.The higher the surface active agents,the higher the conductivity and the lower the breakdown field strength;the breakdown field strength is inversely proportional to the moisture content,and the breakdown field strength is between2.5 kV/cm and 7.5 kV/cm.