Low-cost shale gas fracturing flow-back fluid treatment system and treatment method

Abstract

The invention discloses a low-cost shale gas fracturing flow-back fluid treatment system and treatment method, wherein the low-cost shale gas fracturing flow-back fluid treatment system comprises a gel breaking impurity removal system, a high-pressure nanofiltration membrane system and a high-pressure reverse osmosis membrane system; the input end of the gel breaking impurity removal system is communicated with a fracturing flow-back fluid conveying pipeline, and the output end of the gel breaking impurity removal system is communicated with the high-pressure nanofiltration membrane system; the produced water output end of the high-pressure nanofiltration membrane system is communicated with the high-pressure reverse osmosis membrane system, and the concentrated water output end of the high-pressure nanofiltration membrane system is communicated with a curing system; and the produced water output end of the high-pressure reverse osmosis membrane system is communicated with a recycled water conveying pipeline, and the concentrated water output end of the high-pressure reverse osmosis membrane system is communicated with an evaporation system. According to the treatment system and the treatment method, pollutants such as high-content organic matters, calcium and magnesium and salt in the fracturing flow-back fluid can be effectively treated, and the water resource environment is protected; compared with an existing treatment mode, the treatment method has the advantages that the treatment cost is low, the recovery rate of produced water is high, finally produced NaCl salt meets the standard of first-grade dry salt of 'industrial salt' (GB / T5462-2015), resource utilization can be achieved, and the environmental protection problem of shale gas exploitation enterprises is solved.

Description

technical field [0001] The invention relates to the technical field of fracturing flowback fluid treatment engineering in the shale gas exploitation process, in particular to a low-cost shale gas fracturing flowback fluid treatment system and treatment method. Background technique [0002] Shale gas is natural gas that occurs in shale formations, which belongs to unconventional natural gas, and is mainly exploited by hydraulic fracturing. Hydraulic fracturing is a mining method that uses high pressure to drive fracturing fluid into the ground to hydraulically break the formation, thereby releasing the oil or natural gas reserves therein. After the hydraulic fracturing operation is completed, part of the liquid will be drained back to the ground, which is called fracturing flowback fluid. The fracturing of a single shale gas well often consumes more than 20,000 m3 of water, and 10% to 50% of the flowback is flowed back before completion. In the production stage, the flowback...

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Problems solved by technology

[0006] Aiming at the technical problems of high cost and low recovery rate existing in the existing fracturing flowback fluid treatment methods, the present invention provides a low-cost shale gas fracturing flowback fluid treatment system and treatment method. The treatment system of the present invention And the treatment method can effectively treat the high content of organic matter, calcium and magnesium, salt and other pollutants in the fracturing flowback fluid, and at the same time improve the water recycling rate, which not only protects the water resource environment, but also reduces the treatment cost and promotes page The stable development of rock gas mining enterprises overcomes the shortcomings of existing technologies

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