Screening Of Demulsifier For Nan Yi Station Produced Fluids And Produced Water Treatment

In this paper, we introduce formation and stability of crude oil emulsion, influential factors of demulsification, demulsification mechanism and so on. According to Dagang oil field's being main problem in dehydration process of crude oil emulsion, we carried out research work indoor. For different oil emulsion, proper demulsifier was screened respectively. And deal with produced water to standard, we selected and determined pharmacy of produced water and compatibility study.Indoor evaluation shows that the excellent performance demulsifier KYST-4 for Dagang crude oil has been screened by way of bottles test. The recovery of dehydration conditions was optimized and pharmaceutical experiments support: the applied conditions of demulsifier KYST-4 for the Dagang mixed oil and Chenghai crude oil are the best temperature at 50℃, the optimal concentration of 25mg/L. The conditions of demulsifier KYST-4 for the Wang-xz crude oil are the best temperature at 50℃, the optimal concentration of 10mg/L. The interfacial tension method was employed to analyze the effect of the interface tension for crude oil, colloid, and the asphalt component. It was found that the emulsifier apparently reducing interface tension in between crude oil (or four components) / water, is the better emulsifier for the effect of dehydration. The lowest concentration of demulsifiers obtained by bottle test method is consistent with the results of interface tension screening method.Due to the problems of produced water in the suspension of solid content, high oil content and poor stability. We selected excellent purifying agent for demulsifier with good compatibility. And then we selected other three reagents (anti-scaling agent, corrosion inhibitor and antiseptic) for purifying agent with good compatibility. The study indicates that the optimal concentration of purifying agent is 50mg/L. The best anti-scaling agent is HEDP and its optimal concentration is 1mg/L. It has good compatibility with purifying agent. Addition of corrosion inhibitor and antiseptic slightly affected anti-scaling agent and purifying agent.