Selection and Evaluation of Demulsifier Applied to Aging Crude Oil Dehydration

The aging crude oil of oil fields is the oil over a long time and has a large number of breeds such as FeS, which is difficult to deal with. When the complex recovery fluid such as ground raw oil, bailing oil get into the electric dehydration system, the electric dehydration devices have frequent tripping and affect the normal production. In this paper, according to "two-stage" process in Daqing Yushulin Oilfield gathering station, the experiment about adaptability evaluation on different chemical demulsifiers on dehydrating of aging oil was carried out. Indoor evaluation results show that, the adaptation of agent is directly related to moisture content of oil purification and oil indicators of wastewater after dehydration, also related to the level of electric current in electric dehydration. Non-ionic oil-soluble demulsifier licensing EC2020A with the adding amount of 30 ~ 50mg/L, can make the recovery fluid with mixing ratio of 1.5% ground oil, 50% of the proportion of bailing oil has the water content after dehydration below 0.5%, whereas oil content in dehydrated water below 500 mg/L and dehydration electric current within 100 mA, which can ease the impact of electric field in electro-chemical dehydration.