Technology for treating oil extraction-generated waste water

Abstract

The invention provides a technology for treating oil extraction-generated waste water, which is particularly applied to separating crude oil from suspended matter in oil extraction-generated waste water in oil field. The technology adopts a 'coalescence flotation-carrier flotation' secondary oil extraction-generated waste water treatment technology, which comprises the following steps of: mixing the oil extraction-generated waste water with foaming agent through a I pretreater, and performing flotation to the mixture with a coalescence flotation column; after the coalescence flotation column coalescence and the flotation separation, adding oil-containing waste water which is discharged from the coalescence flotation column into a II pretreater; quantificationally adding coal powder or tar slag into the oil-containing waste water; mixing with the II pretreater, and performing the flotation to the mixture though a carrier flotation column again; discharging the scum which is formed by the carrier flotation column flotation separation of the crude oil, the suspended matter, the coal powder or the tar slag through a foam collecting slot from the top of the carrier flotation column; and discharging purified water from the bottom of the carrier flotation column to recover the crude oil and guarantee the quality of the discharged water. The technology has simple flow process, small lower limit of effective floating granularity, high treating efficiency, short separating time, large treating quantity, small floor area, low operation cost and no sludge.

Description

technical field [0001] The invention relates to a treatment process for oil production sewage, especially suitable for the treatment of oil production sewage in oil field development and production, and also suitable for the purification treatment of oily sewage produced in mechanical processing, food processing, textile industry, transportation industry and other industries. technical background [0002] Oil extraction wastewater treatment is an important issue faced by oil development and production activities and environmental protection. Many oilfields in our country have entered the medium and high water content production stage in the middle and late stages of oil production, and the treatment of extensive oil production wastewater has become one of the major problems in production. [0003] There are many oil extraction wastewater treatment processes, but due to the complex components of oil extraction wastewater, the oil content and the occurrence form in the wastewa...

AI Technical Summary

Problems solved by technology

However, the overall treatment efficiency of the traditional "natural sedimentation-coagulation sedimentation-filtration" treatment process is reduced, and there is an increase in the time of sewage sedimentation and separation, and the effect of oil-water separation is deteriorated; the dosage of purification agent increases, and the cost of purification agent increases; flocculation and sedimentation The amount of sludge produced in the end increases, and dehydration is difficult; the quality of waste oil recovery decreases, and it is no longer suitable for the needs of polymer-containing sewage treatment.

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