Fracturing flow-back fluid treatment device

Abstract

The utility model discloses a fracturing flow-back fluid treatment device, and belongs to the field of oil and gas field wastewater treatment. The fracturing flow-back fluid treatment device comprises a homogeneous regulation tank, a demulsifier adding device, an air flotation treatment tank, a hydrogen peroxide adding device, an ozone adding device, an oxidation gel breaking reactor, a sodium carbonate adding device, a caustic soda adding device, a hardness removal tank, a ceramic membrane ultrafiltration system, a first circulating pump, a water producing tank, a first pH adding device, a salt-tolerant bioreactor and a high-pressure reverse osmosis unit, the low-temperature evaporation crystallization unit is connected with the sludge collection tank; the third reuse water tank is connected with the drying device. Aiming at the characteristics of high salinity and high viscosity of the fracturing flow-back fluid, the fracturing flow-back fluid treatment device with the functions of air flotation oil removal, advanced oxidation gel breaking, salt-tolerant biological treatment and high-pressure membrane treatment is provided, the overall structural design is reasonable, the treatment cost is low, and the fracturing flow-back fluid treatment device is suitable for regions with large shale gas reserves, poor geological conditions, weak ecological environments and underdeveloped economy. The utility model provides an economical and feasible pressure reverse discharge liquid treatment device.

Description

Technical Field

[0001] The utility model relates to the field of oil and gas field wastewater treatment, in particular to a fracturing flowback fluid treatment device. Background Art

[0002] In recent years, with the rapid development of the world economy, energy consumption has continued to increase, and conventional oil and gas resources have become increasingly depleted. The exploitation and mining of shale gas has become a new growth point for energy supply. Shale gas refers to unconventional natural gas that exists in organic-rich mudstone and its interlayers and mainly exists in adsorption and free states. It is a clean and efficient energy resource and chemical raw material.

[0003] The development of unconventional oil and gas resources such as shale gas usually requires the use of large-scale horizontal well multi-stage fracturing technology, which requires the use of a large amount of fracturing fluid. As an effective way to increase the yield of oil and gas layers, hydraulic fracturing technology has played a huge role in increasing the production of oil and gas wells, increasing water well injection, and improving low permeability, and has been rapidly developed and widely used. In the process of shale gas extraction, especially when fracturing fluid is used for shale gas fracturing, about 15% to 75% of the fracturing fluid will flow back with the shale gas to form fracturing flowback fluid.

[0004] With the continuous advancement of hydraulic fracturing technology, the potential environmental threats caused by fracturing measures have become increasingly prominent. The fracturing flowback fluid produced during the fracturing process contains chemical additives, as well as petroleum hydrocarbons, mineral salts, heavy metals, radioactive materials, etc. in some formations, which are relatively harmful to the environment. If the fracturing flowback fluid is not properly disposed and treated and directly discharged, it will pollute groundwater and surface water, and thus endanger human health. Therefore, it is very important to study the treatment methods of fracturing flowback fluid.

[0005] At present, the main treatment methods for fracturing are deep well injection, natural evaporation in evaporation ponds and transportation to centralized points for treatment. The treatment methods are mostly to add drugs to form physical and chemical reactions. This method is expensive and will also cause secondary pollution.

[0006] Therefore, how to simplify the treatment process of fracturing flowback fluid and reduce the treatment cost is of great significance for the effective disposal of fracturing flowback fluid. Utility Model Content

[0007] The utility model aims to provide a fracturing flowback fluid processing device to simplify the fracturing flowback fluid processing process and reduce the processing cost.

[0008] In order to achieve the above purpose, this application adopts the following technical solutions:

[0009] A fracturing flowback fluid processing device, comprising:

[0010] Homogenizing regulating tank, the fracturing flowback fluid to be treated can be sent into the homogenizing regulating tank for homogenizing and equalizing treatment;

[0011] A demulsifier adding device, which is connected to the air flotation treatment tank and can add demulsifier into the air flotation treatment tank;

[0012] A flocculant adding device, which is connected to the air flotation treatment tank and can add flocculants into the air flotation treatment tank;

[0013] The flotation treatment tank is connected to the homogenization regulating tank, and the wastewater in the homogenization regulating tank can be sent to the flotation treatment tank to react with demulsifiers and flocculants to achieve demulsification and flocculation treatment; the microbubbles generated in the flotation treatment tank can suspend the oil substances, particulate matter and colloids suspended in the water;

[0014] A hydrogen peroxide adding device is connected to the oxidation degelling reactor and can add hydrogen peroxide to the oxidation degelling reactor;

[0015] An ozone adding device is connected to the oxidation degumming reactor and can introduce ozone into the oxidation degumming reactor;

[0016] The oxidation degelling reactor is connected to the flotation treatment tank and the wastewater in the flotation treatment tank can be sent to the oxidation degelling reactor to react with hydrogen peroxide and ozone to achieve advanced oxidation treatment;

[0017] A soda ash adding device is connected to the hardness removal tank and can add soda ash into the hardness removal tank;

[0018] A caustic soda adding device is connected to the hardness removal tank and can add caustic soda into the hardness removal tank;

[0019] The hardness removal tank is connected to the oxidation degelling reactor and the wastewater in the oxidation degelling reactor can be sent to the hardness removal tank to react with caustic soda and soda ash to achieve hardness removal treatment;

[0020] The ceramic membrane ultrafiltration system is connected to the hardness removal tank and the wastewater in the hardness removal tank can be sent to the ceramic membrane ultrafiltration system for mud and water separation treatment;

[0021] The first circulation pump has a water inlet connected to the ceramic membrane ultrafiltration system and a water outlet connected to the hardness removal tank, and part of the wastewater generated by the ceramic membrane ultrafiltration system can be returned to the hardness removal tank for secondary hardness removal treatment;

[0022] A water production pool, which is connected to the ceramic membrane ultrafiltration system, and the water produced by the ceramic membrane ultrafiltration system can enter the water production pool;

[0023] A first pH adding device, which is connected to the water production pool, and the first pH adding device can add an acid-base regulator to the water production pool;

[0024] The salt-tolerant bioreactor is connected to the water production pool, and the wastewater in the water production pool can enter the salt-tolerant bioreactor for biochemical treatment to degrade the residual organic matter in the wastewater and obtain the second backwash drainage and the second mud-water mixture respectively;

[0025] A high-pressure reverse osmosis unit is connected to the salt-tolerant bioreactor, and the second mud-water mixture produced by the salt-tolerant bioreactor can enter the high-pressure reverse osmosis unit for mud-water separation treatment, and obtain third treated water and third treated concentrated liquid respectively;

[0026] A low-temperature evaporation crystallization unit is connected to the high-pressure reverse osmosis unit, and the third treated concentrated liquid produced by the high-pressure reverse osmosis unit can enter the low-temperature evaporation crystallization unit for evaporation and crystallization to obtain a fourth mud salt crystal product;

[0027] Sludge collection tank;

[0028] The air flotation treatment tank is connected to the sludge collection tank, and the floating oil and scum in the air flotation treatment tank can enter the sludge collection tank for treatment, and the hardness removal tank is connected to the sludge collection tank, and the sludge in the hardness removal tank can enter the sludge collection tank for treatment;

[0029] The salt-tolerant bioreactor is connected to the homogenization regulating tank, and the second backwash water produced by the salt-tolerant bioreactor can be returned to the homogenization regulating tank for reuse.

[0030] It also includes a first stirring device, which is arranged in the homogenization regulating tank and can fully mix the fracturing return fluid in the homogenization regulating tank.

[0031] It also includes a first intermediate water tank, which is connected to the air flotation treatment tank and the wastewater after treatment in the air flotation treatment tank can enter the first intermediate water tank for temporary storage treatment;

[0032] The first intermediate water tank is connected to the oxidation degelling reactor and the wastewater in the first intermediate water tank can enter the oxidation degelling reactor for treatment.

[0033] It also includes a second intermediate water tank, which is connected to the salt-tolerant bioreactor and the second mud-water mixture after being treated by the salt-tolerant bioreactor can enter the second intermediate water tank for temporary storage treatment;

[0034] The second intermediate water tank is connected to the high-pressure reverse osmosis unit and the wastewater in the first intermediate water tank can enter the high-pressure reverse osmosis unit for treatment.

[0035] It also includes a second backwash pump, the water inlet of the second backwash pump is connected to the second intermediate water tank, the water outlet of the second backwash pump is connected to the salt-tolerant bioreactor, and the second backwash pump can send water in the second intermediate water tank into the salt-tolerant bioreactor for backwashing.

[0036] It also includes a third reuse water pool, the high-pressure reverse osmosis unit is connected to the third reuse water pool, and the third treated water produced by the high-pressure reverse osmosis unit can be returned to the third reuse water pool for temporary storage.

[0037] The third recycled water tank is connected to the homogenization regulating tank.

[0038] The operating temperature of the low-temperature evaporation crystallization unit is 35-70°C.

[0039] It also includes a drying device, the low-temperature evaporation crystallization unit is connected to the drying device, and the fourth mud salt crystal product produced by the low-temperature evaporation crystallization unit can be sent to the drying device for drying treatment.

[0040] In response to the above problems, the present application provides a fracturing return fluid treatment device. Different from traditional physical and chemical treatment process equipment, the present application adopts the "air flotation oil removal + advanced oxidation gel breaking + salt-resistant biological treatment + high-pressure membrane treatment" treatment process and device, which can effectively reduce the treatment cost and reduce the generation of secondary pollutants. The present application is cleverly designed and reasonably conceived, providing a new treatment equipment for the treatment of fracturing return fluid, and also providing an economical and feasible pressure return fluid treatment device for areas with large shale gas reserves, poor geological conditions, weak ecological environment, and underdeveloped economy.

[0041] In summary, due to the adoption of the above technical solution, the beneficial effects of the utility model are:

[0042] (1) This application innovatively adopts a treatment method that combines ceramic membrane ultrafiltration with high-pressure reverse osmosis to achieve effective treatment of high-salinity wastewater. While ensuring effective removal of organic matter, it can stably treat chloride ions with a concentration of up to 10,000 mg / L, with significant treatment effects;

[0043] (2) This application implements sewage diversion treatment based on the planning principle of sewage diversion and quality-based treatment, and treats sewage differently based on its different treatment stages, so as to achieve good treatment results;

[0044] (3) This application has the advantages of low treatment cost, less secondary pollutants, simple and convenient operation, stable treatment effect, and can meet the requirements of continuous operation all year round to ensure that the effluent water quality meets the discharge standards;

[0045] (4) The wastewater treated in this application can meet the process and water quality standards for industrial water used in urban sewage recycling. After the remaining concentrated brine passes through a low-temperature evaporation crystallization drying system, the salt mud is transported out for treatment, which can be used as a resource;

[0046] (5) In view of the high salinity and high viscosity of fracturing return fluid, this application proposes a fracturing return fluid treatment device of "air flotation oil removal + advanced oxidation degelling + salt-tolerant biological treatment + high-pressure membrane treatment". The overall structural design is reasonable and the treatment cost is low. It provides an economical and feasible pressure return fluid treatment device for areas with large shale gas reserves, poor geological conditions, weak ecological environment and underdeveloped economy. BRIEF DESCRIPTION OF THE DRAWINGS

[0047] Figure 1 Schematic diagram of the structure of the device in Example 1.

[0048] Markings in the figure: 1. Homogenizing regulating tank, 2. Flotation treatment tank, 3. Demulsifier adding device, 4. Flocculant adding device, 5. Hydrogen peroxide adding device, 6. Ozone adding device, 7. Oxidation degelling reactor, 8. Soda ash adding device, 9. Caustic soda adding device, 10. Hardness removal tank, 11. Ceramic membrane ultrafiltration system, 12. Water production tank, 13. First pH adding device, 14. Salt-tolerant bioreactor, 15. High-pressure reverse osmosis unit, 16. Low-temperature evaporation crystallization unit, 17. Sludge collection tank, 18. First intermediate water tank, 19. Second intermediate water tank, 20. Third reuse water tank, 21. Drying device. DETAILED DESCRIPTION

[0049] The utility model is described in detail below in conjunction with the accompanying drawings.

[0050] In order to make the purpose, technical solution and advantages of the utility model more clear, the utility model is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described here are only used to explain the utility model and are not used to limit the utility model.

[0051] This embodiment provides a fracturing flowback fluid treatment device, which includes a homogenizing regulating tank, a demulsifier adding device, a flocculant adding device, a flotation treatment tank, a hydrogen peroxide adding device, an ozone adding device, an oxidation degelling reactor, a soda ash adding device, a caustic soda adding device, a hardness removal tank, a ceramic membrane ultrafiltration system, a first circulation pump, a water production tank, a first pH adding device, a salt-tolerant bioreactor, a high-pressure reverse osmosis unit, a low-temperature evaporation crystallization unit, a sludge collection tank, a third reuse water tank, and a drying device. Among them, the fracturing flowback fluid to be treated can be sent to the homogenizing regulating tank; in the homogenizing regulating tank, the fracturing flowback fluid is firstly treated with homogenization and equalization.

[0052] The flotation treatment tank is connected to the homogenization regulating tank, and the wastewater in the homogenization regulating tank can be sent to the flotation treatment tank to react with the demulsifier and flocculant, and the microbubbles generated in the flotation treatment tank can suspend the oil substances, particulate matter, and colloids suspended in the water. The demulsifier adding device and the flocculant adding device are respectively connected to the flotation treatment tank, and the demulsifier adding device can add demulsifier to the flotation treatment tank, and the flocculant adding device can add flocculant to the flotation treatment tank. In the present application, the purpose of oil breaking and flocculation precipitation can be achieved by adding flocculants and demulsifiers to the flotation treatment tank.

[0053] The flotation treatment tank is connected to the oxidation degelling reactor; the wastewater in the flotation treatment tank can be sent to the oxidation degelling reactor to react with hydrogen peroxide and ozone to achieve advanced oxidation treatment. The hydrogen peroxide adding device and the ozone adding device are respectively connected to the oxidation degelling reactor, and the hydrogen peroxide adding device can add hydrogen peroxide to the oxidation degelling reactor, and the ozone adding device can introduce ozone into the oxidation degelling reactor.

[0054] The oxidation debonding reactor is connected to the hardness removal tank, and the wastewater in the oxidation debonding reactor can be sent to the hardness removal tank to react with caustic soda and soda ash to achieve hardness removal treatment. The soda ash adding device and the caustic soda adding device are respectively connected to the hardness removal tank, and the soda ash adding device can add soda ash to the hardness removal tank, and the caustic soda adding device can add caustic soda to the hardness removal tank.

[0055] The hardness removal tank is connected to the ceramic membrane ultrafiltration system, and the wastewater in the hardness removal tank can be sent to the ceramic membrane ultrafiltration system for mud and water separation treatment. The water inlet end of the first circulation pump is connected to the ceramic membrane ultrafiltration system, and the water outlet end of the first circulation pump is connected to the hardness removal tank, and part of the wastewater generated by the ceramic membrane ultrafiltration system can be returned to the hardness removal tank for secondary hardness removal treatment. The ceramic membrane ultrafiltration system is connected to the water production tank, and the water produced by the ceramic membrane ultrafiltration system can enter the water production tank; the first pH adding device is connected to the water production tank, and the first pH adding device can add an acid-base regulator to the water production tank to make the pH value of the water in the water production tank within the range of 6.0~8.0, thereby meeting the growth needs of microorganisms in the subsequent salt-tolerant bioreactor. The water production tank is connected to the salt-tolerant bioreactor, and the wastewater in the water production tank can enter the salt-tolerant bioreactor for biochemical treatment to degrade the residual organic matter in the wastewater, and obtain the second backwash drainage and the second mud-water mixture respectively.

[0056] The salt-tolerant bioreactor is connected to the high-pressure reverse osmosis unit, and the second mud-water mixture produced by the salt-tolerant bioreactor can enter the high-pressure reverse osmosis unit for mud-water separation treatment, and obtain the third treated water and the third treated concentrated liquid respectively. The high-pressure reverse osmosis unit is connected to the third reuse water pool, and the third treated water produced by the high-pressure reverse osmosis unit can be returned to the third reuse water pool for temporary storage. The high-pressure reverse osmosis unit is connected to the low-temperature evaporation crystallization unit, and the third treated concentrated liquid produced by the high-pressure reverse osmosis unit can enter the low-temperature evaporation crystallization unit for evaporation and crystallization, and obtain the fourth mud salt crystal product. The low-temperature evaporation crystallization unit is connected to the drying device, and the fourth mud salt crystal product produced by the low-temperature evaporation crystallization unit can be sent to the drying device for drying treatment. The mud salt produced by drying can be transported out for treatment.

[0057] In this embodiment, the salt-tolerant bioreactor is connected to the homogenizing regulating tank, and the second backwash water produced by the salt-tolerant bioreactor can be returned to the homogenizing regulating tank for reuse. The flotation treatment tank is connected to the sludge collection tank, and the floating oil and scum in the flotation treatment tank can enter the sludge collection tank for treatment. The hardness removal tank is connected to the sludge collection tank, and the sludge in the hardness removal tank can enter the sludge collection tank for treatment.

[0058] Furthermore, in this embodiment, a first intermediate water tank is also included, which is connected to the flotation treatment tank, and the wastewater after treatment in the flotation treatment tank can enter the first intermediate water tank for temporary storage treatment; the first intermediate water tank is connected to the oxidation degelling reactor, and the wastewater in the first intermediate water tank can enter the oxidation degelling reactor for treatment.

[0059] Furthermore, it also includes a second intermediate water tank, which is connected to the salt-tolerant bioreactor, and the second mud-water mixture after being treated by the salt-tolerant bioreactor can enter the second intermediate water tank for temporary storage treatment; the second intermediate water tank is connected to the high-pressure reverse osmosis unit, and the wastewater in the first intermediate water tank can enter the high-pressure reverse osmosis unit for treatment. It also includes a second backwash pump, the water inlet end of the second backwash pump is connected to the second intermediate water tank, the water outlet end of the second backwash pump is connected to the salt-tolerant bioreactor, and the second backwash pump can send the water in the second intermediate water tank into the salt-tolerant bioreactor for backwashing.

[0060] Furthermore, it also includes a first stirring device. The first stirring device is arranged in the homogenization regulating tank, and the first stirring device can fully mix the fracturing return fluid in the homogenization regulating tank. Furthermore, the third reuse water tank is connected to the homogenization regulating tank.

[0061] The working process of the device for processing fracturing flowback fluid is as follows:

[0062] (1) The fracturing flowback fluid is first collected in a homogenizing regulating tank and fully mixed by mechanical stirring. Then, the wastewater in the homogenizing regulating tank is pumped to the flotation treatment tank. In the flotation treatment tank, the microbubbles generated by the flotation treatment tank are used to support and remove the oil, fine particles and colloids suspended in the water, laying a foundation for providing good water quality for subsequent treatment units.

[0063] (2) The effluent from the flotation treatment tank flows into the oxidation degelling reactor, which uses the synergistic effect of ozone catalytic oxidation and hydrogen peroxide to produce hydroxyl free radicals with extremely strong oxidizing effects, strengthen degelling, mineralization and oxidation of organic matter in the wastewater, and at the same time improve the biodegradability of the wastewater;

[0064] (3) The effluent from the oxidation degelling reactor flows into the hardness removal tank, where double alkali (sodium carbonate and sodium hydroxide) is added to react with the Ca in the wastewater. 2+ Mg 2+ The reaction forms an insoluble precipitate, which is subsequently removed by a ceramic membrane ultrafiltration system;

[0065] Different from the traditional sedimentation tank, the present application adopts the ceramic membrane ultrafiltration system, whose unique large channel can effectively intercept the sludge and will not cause the membrane tube to be blocked or blocked by dirt; the ceramic membrane ultrafiltration system is used to separate mud and water, and obtain high-quality ultrafiltration water, and the calcium and magnesium ion precipitates enter the sludge collection tank;

[0066] (4) The produced water of the ceramic membrane ultrafiltration system enters the salt-tolerant bioreactor. Through hydraulic circulation, it can quickly cultivate and domesticate suitable dominant bacteria and microorganisms. The microorganisms are used to deeply degrade the organic matter remaining in the wastewater, so that the CODcr in the wastewater is further reduced.

[0067] (5) The effluent from the salt-tolerant bioreactor enters the high-pressure reverse osmosis unit for treatment; the high-pressure reverse osmosis unit produces the third treated water and the third treated concentrate. The third treated water can meet the discharge requirements and can be discharged directly or sent to the third reuse water pool;

[0068] (6) The third treated concentrated liquid produced by the high pressure reverse osmosis unit is sent to the low temperature evaporation crystallization unit; after being treated by the low temperature evaporation crystallization unit, the salt mud with a moisture content of ≤30% is dried and bagged for external disposal.

[0069] Preferably, the operating temperature of the low temperature evaporation crystallization unit is 35-70°C.

[0070] Example 1

[0071] The fracturing flowback fluid of a natural gas well contains TDS23500mg / L and COD1276 mg / L.

[0072] The above-mentioned device was used to treat the water, and the treated water had a TDS of 896 mg / L and a COD of 84 mg / L, and the water content of the salt mud was less than 5%, which met the water quality requirements for fracturing return fluid reinjection.

[0073] Example 2

[0074] The fracturing flowback fluid of a natural gas well contains TDS18200mg / L and COD976 mg / L.

[0075] The above-mentioned device was used to treat the water, and the treated water had a TDS of 576 mg / L and a COD of 47 mg / L, and the water content of the salt mud was less than 5%, which met the water quality requirements for fracturing return fluid injection.

[0076] Example 3

[0077] The fracturing flowback fluid of a natural gas well contains TDS13680mg / L and COD1459 mg / L.

[0078] The above-mentioned device was used to treat the water, and the treated water had a TDS of 439 mg / L and a COD of 63 mg / L, and the water content of the salt mud was less than 5%, which met the water quality requirements for fracturing return fluid injection.

[0079] Example 4

[0080] The fracturing flowback fluid of a natural gas well contains TDS28050mg / L and COD2628 mg / L.

[0081] The above-mentioned device was used to treat the water, and the treated water had a TDS of 984 mg / L and a COD of 146 mg / L, and the water content of the salt mud was less than 5%, which met the water quality requirements for fracturing return fluid reinjection.

[0082] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A fracturing flowback fluid processing device, characterized in that: include: Homogenizing regulating tank, the fracturing flowback fluid to be treated can be sent into the homogenizing regulating tank for homogenizing and equalizing treatment; A demulsifier adding device, which is connected to the air flotation treatment tank and can add demulsifier into the air flotation treatment tank; A flocculant adding device, which is connected to the air flotation treatment tank and can add flocculants into the air flotation treatment tank; The flotation treatment tank is connected to the homogenization regulating tank, and the wastewater in the homogenization regulating tank can be sent to the flotation treatment tank to react with demulsifiers and flocculants to achieve demulsification and flocculation treatment; the microbubbles generated in the flotation treatment tank can suspend the oil substances, particulate matter and colloids suspended in the water; A hydrogen peroxide adding device is connected to the oxidation degelling reactor and can add hydrogen peroxide to the oxidation degelling reactor; An ozone adding device is connected to the oxidation degumming reactor and can introduce ozone into the oxidation degumming reactor; The oxidation degelling reactor is connected to the flotation treatment tank and the wastewater in the flotation treatment tank can be sent to the oxidation degelling reactor to react with hydrogen peroxide and ozone to achieve advanced oxidation treatment; A soda ash adding device is connected to the hardness removal tank and can add soda ash into the hardness removal tank; A caustic soda adding device is connected to the hardness removal tank and can add caustic soda into the hardness removal tank; The hardness removal tank is connected to the oxidation degelling reactor and the wastewater in the oxidation degelling reactor can be sent to the hardness removal tank to react with caustic soda and soda ash to achieve hardness removal treatment; The ceramic membrane ultrafiltration system is connected to the hardness removal tank and the wastewater in the hardness removal tank can be sent to the ceramic membrane ultrafiltration system for mud and water separation treatment; The first circulation pump has a water inlet connected to the ceramic membrane ultrafiltration system and a water outlet connected to the hardness removal tank, and part of the wastewater generated by the ceramic membrane ultrafiltration system can be returned to the hardness removal tank for secondary hardness removal treatment; A water production pool, which is connected to the ceramic membrane ultrafiltration system, and the water produced by the ceramic membrane ultrafiltration system can enter the water production pool; A first pH adding device, which is connected to the water production pool, and the first pH adding device can add an acid-base regulator to the water production pool; The salt-tolerant bioreactor is connected to the water production pool, and the wastewater in the water production pool can enter the salt-tolerant bioreactor for biochemical treatment to degrade the residual organic matter in the wastewater and obtain the second backwash drainage and the second mud-water mixture respectively; A high-pressure reverse osmosis unit is connected to the salt-tolerant bioreactor, and the second mud-water mixture produced by the salt-tolerant bioreactor can enter the high-pressure reverse osmosis unit for mud-water separation treatment, and obtain third treated water and third treated concentrated liquid respectively; A low-temperature evaporation crystallization unit is connected to the high-pressure reverse osmosis unit, and the third treated concentrated liquid produced by the high-pressure reverse osmosis unit can enter the low-temperature evaporation crystallization unit for evaporation and crystallization to obtain a fourth mud salt crystal product; Sludge collection tank; The air flotation treatment tank is connected to the sludge collection tank, and the floating oil and scum in the air flotation treatment tank can enter the sludge collection tank for treatment, and the hardness removal tank is connected to the sludge collection tank, and the sludge in the hardness removal tank can enter the sludge collection tank for treatment; The salt-tolerant bioreactor is connected to the homogenization regulating tank, and the second backwash water produced by the salt-tolerant bioreactor can be returned to the homogenization regulating tank for reuse.

2. The fracturing flowback fluid processing device according to claim 1, characterized in that: It also includes a first stirring device, which is arranged in the homogenization regulating tank and can fully mix the fracturing return fluid in the homogenization regulating tank.

3. The fracturing flowback fluid processing device according to claim 1 or 2, characterized in that: It also includes a first intermediate water tank, which is connected to the air flotation treatment tank and the wastewater after treatment in the air flotation treatment tank can enter the first intermediate water tank for temporary storage treatment; The first intermediate water tank is connected to the oxidation degelling reactor and the wastewater in the first intermediate water tank can enter the oxidation degelling reactor for treatment.

4. The fracturing flowback fluid processing device according to claim 3, characterized in that: It also includes a second intermediate water tank, which is connected to the salt-tolerant bioreactor and the second mud-water mixture after being treated by the salt-tolerant bioreactor can enter the second intermediate water tank for temporary storage treatment; The second intermediate water tank is connected to the high-pressure reverse osmosis unit and the wastewater in the first intermediate water tank can enter the high-pressure reverse osmosis unit for treatment.

5. The fracturing flowback fluid processing device according to claim 4, characterized in that: It also includes a second backwash pump, the water inlet of the second backwash pump is connected to the second intermediate water tank, the water outlet of the second backwash pump is connected to the salt-tolerant bioreactor, and the second backwash pump can send water in the second intermediate water tank into the salt-tolerant bioreactor for backwashing.

6. The fracturing flowback fluid processing device according to any one of claims 1, 2, 4 to 5, characterized in that: It also includes a third reuse water pool, the high-pressure reverse osmosis unit is connected to the third reuse water pool, and the third treated water produced by the high-pressure reverse osmosis unit can be returned to the third reuse water pool for temporary storage.

7. The fracturing flowback fluid processing device according to claim 6, characterized in that: The third recycled water tank is connected to the homogenization regulating tank.

8. The fracturing flowback fluid processing device according to claim 1, characterized in that: It also includes a drying device, the low-temperature evaporation crystallization unit is connected to the drying device, and the fourth mud salt crystal product produced by the low-temperature evaporation crystallization unit can be sent to the drying device for drying treatment.

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