Recycling treatment method and device for fracturing flow-back fluid

Abstract

The invention provides a recycling treatment method and device for fracturing flow-back fluid. The method comprises the following steps: sequentially carrying out electric flocculation treatment, electroflotation treatment, electro-catalysis treatment and electro-adsorption treatment on the fracturing flow-back fluid to obtain desalted fresh water and electro-adsorbed concentrated water; and adding an alkali into the concentrated water subjected to electro-adsorption to remove hardness, conducting filtering, and subjecting filtered water to bipolar membrane electrodialysis treatment to obtain acid, alkali and desalted fresh water. According to the method, petroleum, suspended solids, organic matter, total iron, total mineralization degree, bacteria, total hardness and the like in the fracturing flow-back fluid can be effectively removed through treatment processes such as electric flocculation, electroflotation, electrocatalysis, electroadsorption and the like, and the treated water quality meets the reuse water quality requirement; and meanwhile, the electroadsorbed concentrated water is further subjected to hardness removal, filtration and bipolar membrane electrodialysis treatment, the generated acid can be reused in the production processes of acidification, acid fracturing and the like of an oil field, and the generated alkali can be reused in the alkali-adding hardness removal treatment process, so that zero emission of the fracturing flow-back fluid is really realized.

Description

technical field [0001] The invention belongs to the technical field of oilfield wastewater treatment, and relates to a method and device for recycling treatment of fracturing flowback fluid. Background technique [0002] Fracturing is one of the main measures to increase production of oil and gas wells. During the fracturing construction process, high-viscosity fracturing fluid is injected into the formation by high-pressure pumps, fractures are created and proppant is carried in. After the fracturing is completed, the fracturing fluid must be flowed back. Flowback fluid usually accounts for 70% of the injected fracturing fluid. Since the fracturing flowback fluid contains pollutants such as petroleum hydrocarbons, broken and unbroken guar gum / jelly, polymers, high-concentration salt, heavy metals, and various chemical additives, if the treatment is not up to standard Direct discharge will cause environmental impact. The water quality parameters of fracturing flowback flui...

AI Technical Summary

Problems solved by technology

This method is an effective treatment method for flowback fluid with low total salinity, but it is difficult to realize the reuse of complex fracturing flowback fluid such as high salt and high COD, because the preparation of fresh fracturing fluid and heavy oil steam injection Boiler feed water has strict requirements on the total salinity and organic matter content of water

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