Study On The Technology Of Low-temperature Demulsification Of Shengli Heavy Crude Oil

Aimed at Higher dehydration temperature,longer dehydration time,and high energy consumption of produced fluid in East No4.united station of Gudong oil production plant in Shengli Oil field.Study on demulsification of field heavy crude oil emulsion,the effects of the different demulsifiers,demulsification temperature,demulsifier concentration were studied with field heavy crude oil emulsion,The demulsification conditions were optimized as propanediol polyether demulsifier,temperature 65 ? and concentration 200 ppm.In this condition the dehydration rate can reach 76% in the two hours and 96% in one day.And the temperature can be reduced by 10? compared to the dehydration conditions in practice.The instability of crude oil emulsion was analyzed at low temperature by stability analyzer and the influence of different concentration demulsifier and temperature on the stability of emulsion was analyzed by detaBS and TSI parameters,The microcosmic instability in the upper,middle and lower layers of the emulsion before and after the demulsifier was added at different temperatures was observed using an optical microscope,The stability of the emulsion system become lower after the demulsifier was added,and the droplets were merged and settled,leading to the separation of oil and water.The effect of the combination of ultrasonic and ultrasound on the stability of emulsion was studied at low temperature by using ultrasonic devices,Research results show that when the demulsifier concentration is 150 ppm and the ultrasonic action time is 15 s,the synergistic effect of ultrasonic and demulsifier has the best effect.The rheometer was used to simulate the shear of high water-containing emulsion in the process of gathering.The variation of the viscosity of high water emulsion with shear rate,temperature and moisture content and the effect of the demulsifier on the high water emulsion was studied,Research found that under the condition of low temperature system are greatly influenced by shear rate,at the 80 ? above,the system viscosity basically not influenced by shear rate,phenolic polyether demulsifier has great influence on the viscosity of the system.