Process system and method for demulsification of oil-emulsion-containing sewage

Abstract

The invention discloses a process system and method for demulsification of oil-emulsion-containing sewage through a polytetrafluoroethylene tubular membrane. The process system comprises an emulsion sewage tank, a polytetrafluoroethylene tubular ultrafiltration membrane device, an oil phase recovery tank and a water phase recovery tank. The emulsion sewage tank is connected with the polytetrafluoroethylene tubular ultrafiltration membrane device through a material pump by means of a pipeline. The polytetrafluoroethylene tubular ultrafiltration membrane device is connected with the oil phase recovery tank and the water phase recovery tank. By means of the improved hydrophilic polytetrafluoroethylene tubular ultrafiltration membrane, dispersed phase droplets in an oil-in-water (W / O) emulsionwet the surface of the membrane and are spread to a certain extent; under the thrust of pump pressure, due to the hydrophilia of the membrane, a water phase penetrates through membrane pores for aggregating at different degrees, an organic phase penetrates through the membrane pores for gathering at different degrees, the organic phase and the water phase which penetrate through the pores are separated from the original dispersed medium emulsion, and oil and water in the emulsion are well separated.

Description

technical field [0001] The invention belongs to the field of oily sewage treatment in oilfields, and in particular relates to a process system and method for demulsifying oily sewage in emulsion by using a polytetrafluoroethylene tubular membrane. Background technique [0002] At present, most oilfields in China adopt the water injection development method. As the oilfield enters the late stage of high water content, the oily sewage in the oilfield accounts for about 70% of the total water in the oilfield, mainly from oil production sewage, well washing backwater, drilling sewage, downhole operation sewage, and various waste water in the combined station. Bottom water of crude oil storage tanks. Oily sewage, especially emulsified oily sewage, is inevitably produced in oilfield produced water. Because there are surfactants in the sewage, the oil droplets are emulsified into a stable emulsion and dispersed in water. The particle size of the oil droplets is generally between 1-...

AI Technical Summary

Problems solved by technology

[0004] Most of the demulsification methods disclosed above use the addition of chemical agents for demulsification. The problems are that the cost of the added demulsifier is high, the production process of the demulsifier is complicated, the demulsifier is difficult to degrade in the sewage, and the presence of the added demulsifier causes pollution to the sewage. The problem of secondary pollution

However, there are very few reports on the use of membrane separation for demulsification.

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