Treatment system for oil field fracturing flow-back fluid

Abstract

The utility model discloses a treatment system for oil field fracturing flow-back fluid, and belongs to the field of oil field fracturing flow-back fluid treatment. The treatment system for the oil field fracturing flow-back fluid comprises a raw water collecting tank for storing the fracturing flow-back fluid generated in the oil field drainage process; the filtering module is connected with the raw water collecting tank; the cavitation oil skimming module is connected with the filtering module, and the cavitation oil skimming module comprises a hydrodynamic cavitation generating device; a first floating oil collector is arranged on the liquid level of the raw water collecting tank and is connected with a first floating oil separating device; and the first floating oil separation device is connected with the raw water collection tank. The oil field fracturing flow-back fluid treatment system provided by the utility model is less in chemical agent addition, simple in process, high in treatment efficiency, low in treatment cost and obvious in oil content, SS content and COD (Chemical Oxygen Demand) degradation effect.

Description

Technical Field

[0001] The utility model relates to the field of oilfield fracturing return water treatment, in particular to the field of oilfield fracturing return water purification treatment, reuse or direct discharge. Background Art

[0002] The large-scale application of horizontal well drilling and staged fracturing has been one of the key technologies that has impacted the oil industry in recent decades. Horizontal wells and staged fracturing have become core technologies for the development of unconventional oil and gas resources, including shale gas, tight gas, and tight oil. While the application of staged fracturing has boosted single-well production to new heights, it also generates significant amounts of fracturing flowback fluid. This fracturing flowback is characterized by high oil content, high COD, and high SS content.

[0003] At present, the main treatment methods for fracturing return fluid are: 1. Reinjection into the safety layer. The advantage of this method is that no substances need to be added. The disadvantages are high equipment requirements, high cost, and limitation by the formation; it is easy to pollute groundwater and oil layers; 2. Evaporation in the drying pool. The advantage of this method is that it reduces the treatment cost. The disadvantages are long treatment cycle, large floor space, solid phase treatment, and the risk of seepage and overflow; 3. Dilution into the joint station. The advantage of this method is that the treatment effect is thorough. The disadvantages are that it increases the treatment load of the joint station, blocks the filter tank, is costly, has high safety risks, and has limited application areas.

[0004] The COD concentration in fracturing flowback fluid can reach as high as 20,000 mg / L, primarily due to the presence of petroleum hydrocarbons. Currently, oil separation and flotation are used, but the remaining COD after separation is still between 7,000 and 8,000 mg / L, making flocculation and sedimentation essential. After flocculation and sedimentation, the solution becomes transparent, but the COD concentration remains between 2,000 and 3,000 mg / L, indicating that the soluble COD is still high. Current methods for treating soluble COD include advanced oxidation, biochemical, and adsorption. However, this fracturing flowback fluid contains high concentrations of salt and macromolecular alkanes with poor biodegradability, making it unsuitable for direct biochemical treatment. Furthermore, the high COD concentration makes direct adsorption unsuitable. Existing treatment methods for fracturing flowback water require the addition of numerous chemical agents, including iron ore, iron oxide, NaOH, and hydrochloric acid, which hinders the recovery and recycling of the fracturing fluid. Oilfield operators generally recommend against the addition of excessive chemical agents. The existing fracturing flowback water treatment process is complex, and generally requires several stages of treatment to reduce COD from greater than 20,000 mg / L to discharge standards, and a lot of chemical agents are added in the process. Summary of the Invention

[0005] In order to solve the above-mentioned problems of existing oilfield fracturing return fluid treatment, the utility model provides an oilfield fracturing return fluid treatment system, which requires less chemical addition, has a simple process, high treatment efficiency, low treatment cost, and obvious degradation effects on oil content, SS content and COD.

[0006] The purpose of this utility model is achieved through the following technical solutions:

[0007] Oilfield fracturing flowback fluid treatment system, including:

[0008] Raw water collection pool, storing fracturing flowback fluid from oilfield production;

[0009] A filtration module connected to the raw water collection tank;

[0010] a cavitation skimming module connected to the filtration module, wherein the cavitation skimming module includes a hydraulic cavitation generating device;

[0011] A first floating oil collector is provided on the liquid surface of the raw water collection tank, and the floating oil collector is connected to a first floating oil separation device.

[0012] Preferably, the filtration module is a plate and frame filter press, and an inlet pump is connected between the plate and frame filter press and the raw water collection tank; and an outlet pump is connected between the plate and frame filter press and the cavitation skimming module.

[0013] Preferably, the cavitation skimming module comprises:

[0014] A cavitation tank is connected to a hydrodynamic cavitation generator, and a booster pump is connected between the hydrodynamic cavitation generator and the cavitation tank; a partition is provided in the middle of the cavitation tank, and the partition separates the cavitation tank into a treatment tank and a degreasing tank;

[0015] The liquid inlet of the hydrodynamic cavitation generating device is connected to the oil removal tank, and the liquid outlet of the hydrodynamic cavitation generating device is connected to the treatment tank.

[0016] Preferably, the cavitation skimming module further comprises:

[0017] An ozone generator is connected to the treatment tank, and an ozone generator gas distribution pipe is provided in the treatment tank.

[0018] Preferably, the distance between the partition and the bottom of the cavitation tank is greater than zero, an overflow port is provided on the partition, and the width of the treatment tank is smaller than that of the degreasing tank.

[0019] Preferably, the cavitation pool is connected to a second floating oil separation device, a second floating oil collector is provided on the liquid surface of the deoiling tank, the second floating oil collector is connected to the second floating oil separation device; and the second floating oil separation device is connected to the treatment tank.

[0020] Preferably, a collection hood is provided above the cavitation pool, and the collection hood is connected to a gas collection device; a gas outlet is provided on the collection hood; the gas collection device includes a fan, the fan suction port is connected to the gas outlet, and the fan outlet is connected to the collection container.

[0021] Preferably, the filtration module includes an inclined plate filter, which includes a dosing chamber and a sedimentation chamber. The dosing chamber is connected to the raw water collection tank, a slag discharge port is provided at the bottom of the sedimentation chamber, and a clean liquid outlet is provided at the top of the sedimentation chamber; the clean liquid outlet is connected to the cavitation skimming module.

[0022] Preferably, the slag discharge port is connected to a plate-frame filter press, a liquid inlet pump is connected between the plate-frame filter press and the slag discharge port, and the plate-frame filter press is connected to the raw water collection tank.

[0023] Now for the existing technology, the beneficial technical effects of the utility model are:

[0024] 1. After being treated by the process equipment of this system, the COD of fracturing return water is less than 60 mg / L, oil is less than 5 mg / L, and SS is less than 50 mg / L. The treated water samples can be reused and discharged directly.

[0025] 2. The process treatment cost of this system design is low, and the treatment cost of each ton of fracturing return fluid is 6 to 9 yuan.

[0026] 3. This system uses a small number of process reagents with low consumption. It only uses PAC and PAM reagents, with consumption no more than 500 mg / L and 5 mg / L respectively. There are no other consumables. Depending on site needs, chemical agents may not be used.

[0027] 4. This system can recover petroleum in fracturing flowback fluid through two floating oil separation processes, and the recovered oil has considerable economic benefits.

[0028] 5. This system has a small size and good mobility. The entire equipment is skid-mounted. Compared with the system using air flotation, the volume of this patented equipment can be reduced by more than 50%.

[0029] 6. The process involved in this system has strong resistance to the impact of hydraulic load and water quality load. It adopts the method of adjusting the cavitation intensity and ozone generator power to adapt to the processing volume needs of different drilling wells. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] Figure 1 This is a flow chart of the oilfield fracturing flowback fluid processing system of the present invention.

[0031] Figure 2 This is a system structure flow chart of Example 1, which is a system for processing oilfield fracturing flowback fluid.

[0032] Figure 3 This is a system structure flow chart of Example 2, which is a system for processing oilfield fracturing flowback fluid.

[0033] In the figure: raw water collection tank 1, first floating oil separation device 2, first floating oil collector 20, oil storage barrel 21, liquid inlet pump 3, plate and frame filter press 4, liquid outlet pump 5, cavitation tank 6, partition 60, overflow port 601, treatment tank 61, oil removal tank 62, hydraulic cavitation generating device 7, booster pump 70, ozone generator 8, air distribution pipe 80, second floating oil separation device 9, second floating oil collector 90, oil storage barrel 91, inclined plate filter 10, dosing chamber 101, sedimentation chamber 102, slag discharge port 103, fan 11, precision filter 12, online monitoring sensor 13. DETAILED DESCRIPTION

[0034] The present invention will be further described below with reference to the accompanying drawings and specific embodiments:

[0035] like Figure 1 The oilfield fracturing flowback treatment system includes a raw water collection tank, a filtration module, and a cavitation skimming module. The raw water collection tank is connected to a floating oil separation device above it, which in turn is connected to the filtration module and the cavitation skimming module. The cavitation skimming module is connected to an ozone generator and a gas collection device, and the cavitation skimming module is connected to the outlet water. The control system provides program control for the filtration module, cavitation skimming module, ozone generator, and gas collection device.

[0036] Example 1:

[0037] like Figure 2 The oilfield fracturing flowback fluid treatment system includes a raw water collection tank 1, which is used to store the fracturing flowback fluid generated during the oilfield production process. A first floating oil collector 20 is provided on the liquid surface of the raw water collection tank 1. The first floating oil collector 20 is connected to the first floating oil separation device 2, and the first floating oil separation device 2 is connected to the raw water collection tank 1. The oil float collector 20 is a floating liquid suction device, and its technical information can be obtained through the stratified liquid capture device of patent CN201921439821.X; the first oil float collector 20 can always float on the liquid surface as the liquid level rises or falls, and collects oil floats of different thicknesses on the liquid surface; the oil float collected by the first oil float collector 20 is introduced into the first oil float separation device 2, and the internal structure of the first oil float separation device 2 can be obtained from the oil skimmer of patent CN201921892786.7, and its technical information; the first oil float separation device 2 is provided with a liquid storage tank, an oil collecting tank, and a return liquid tank. The waste liquid is further separated from the oil in the liquid storage tank, the oil enters the oil collecting tank, and the clean liquid enters the return liquid tank; the liquid after oil-liquid separation, that is, the liquid in the return liquid tank is introduced into the raw water collection tank 1, and the oil is collected by the oil storage barrel 21. The floating oil above the raw water collection tank 1 is skimmed off with high oil removal efficiency and can be recovered. Generally, the proportion of oil in fracturing return water reaches 6-8%, and the economic benefits of recovered oil are considerable.

[0038] like Figure 2The raw water collection tank 1 is connected to a plate-and-frame filter press 4. A liquid inlet pump 3, a diaphragm pump or a particle pump, is connected between the two. Its inlet is located in the lower middle layer of the raw water collection tank 1. The plate-and-frame filter press 4 is provided with a filtrate outlet, which is connected to a cavitation skimming module. The plate-and-frame filter press 4 squeezes and filters solids such as colloids, salt crystals, and rock particles from the wastewater. Due to the pressure applied by the plate-and-frame filter press 4, a relatively dry solid residue is obtained. This solid residue can be collected and treated as solid waste.

[0039] like Figure 2 The cavitation skimming module includes a cavitation tank 6, which is connected to a hydrodynamic cavitation generator 7. A booster pump 70 is connected between the hydrodynamic cavitation generator 7 and the cavitation tank 6. A positive pressure gauge is installed between the booster pump 70 and the hydrodynamic cavitation generator 7. The hydrodynamic cavitation generator 7 has a negative pressure port connected to a negative pressure gauge. A partition 60 is installed in the middle of the cavitation tank 6, dividing the cavitation tank into a treatment tank 61 and an oil removal tank 62. The liquid inlet of the hydrodynamic cavitation generator 7 is connected to the bottom of the oil removal tank 62, and the liquid outlet of the hydrodynamic cavitation generator 7 is connected to the bottom of the treatment tank 61. An ozone generator 8 is connected to the treatment tank 61, and an air distribution pipe 80 for the ozone generator 8 is installed in the treatment tank 61. The distance between the partition 60 and the bottom of the cavitation tank 6 is greater than zero, and the partition 60 is provided with an overflow port 601. The width of the treatment tank 61 is smaller than that of the oil removal tank 62.

[0040] A partition 60 is set in the middle of the cavitation tank 6 to divide the cavitation tank into two chambers. The lower layer of liquid in the degreasing tank 62 that has been stratified is pumped into the hydraulic cavitation generator 7 for hydraulic cavitation treatment, and then introduced into the treatment tank 61. Because the width of the treatment tank 61 is smaller than that of the degreasing tank 62, under the same flow rate, the liquid level in the treatment tank 61 will be higher than that of the degreasing tank 62. An overflow port 601 is formed above the partition 60, so that the floating oil on the upper layer of the treatment tank 61 overflows into the degreasing tank 62 through the overflow port 601.

[0041] Oil droplets larger than 1 μm in diameter float to the liquid surface. Oil droplets smaller than 1 μm typically exist as an oil-in-water emulsion. After hydrodynamic cavitation treatment, the oil-water interface is disrupted, and small droplets collide to form larger droplets, which then float upward. In treatment tank 61, above the liquid outlet of hydrodynamic cavitation generator 7, the emulsion further breaks down, with small droplets coalescing into larger droplets that float to the liquid surface and overflow through overflow port 601 on the partition into oil removal tank 62. The bottom of treatment tank 61 also houses an air distribution pipe 80 for ozone generator 8. Hydrodynamic cavitation and ozone oxidation work synergistically to further oxidize and decompose contaminated oil and other organic matter in the water.

[0042] Cavitation tank 6 is also connected to second oil separator 9. A second oil collector 90 is located above the liquid level of de-oiling tank 62. This second oil collector 90 is connected to second oil separator 9, which is then connected to treatment tank 61. Second oil collector 90 has the same structure as first oil collector 20, but can be scaled down accordingly. Second oil separator 9 has the same structure as first oil separator 2, but can be scaled down accordingly.

[0043] The second floating oil collector 90 collects the floating oil on the degreasing tank surface and introduces the floating oil into the second floating oil separator 9 for further oil-liquid separation. The oil is introduced into the oil storage barrel 91 for collection, and the separated clean liquid is then introduced into the treatment tank 61.

[0044] The second floating oil separator 9 and second floating oil collector 90 further remove oil from the fracturing flowback filtrate in the cavitation tank 6, effectively removing both large oil droplets larger than 1 μm and tramp oil smaller than 1 μm. The synergistic effects of cavitation and ozone further oxidize and decompose tramp oil and other organic matter in the filtrate, thereby further degrading the soluble COD in the fracturing flowback fluid.

[0045] A collection hood is located above the cavitation tank 6 and connected to a gas collection device. The hood is provided with a gas outlet 63. The gas collection device includes a fan 11, whose air intake is connected to the gas outlet and whose air outlet is connected to a collection pipeline. Fracturing flowback fluid contains gases such as H2S and NH3. Hydraulic cavitation vigorously stirs the fluid, causing the gases to escape. The gas collection device then collects the gases for further processing.

[0046] The cavitation tank 6 is provided with a water outlet pipe, and an online monitoring sensor 13 is also provided on the water outlet pipe to perform online monitoring of the particle content, oil content and COD.

[0047] The hydrodynamic cavitation generator 7 comprises a container with a decreasing inner diameter from top to bottom. The container is equipped with a tangentially introduced liquid inlet pipe, a liquid outlet pipe in the middle of the container, a venturi tube structure inside the outlet pipe, and a flow guide below the outlet pipe. A booster pump 70 delivers liquid at a certain pressure into the hydrodynamic cavitation generator. Once inside the hydrodynamic cavitation generator, the liquid forms a cyclonic and laminar flow within the container cavity, similar to a hurricane. The laminar flows rub against each other and shear against each other. As the cyclonic flow rotates downward within the cavity, it accelerates, accelerating. Passing through the throat of the venturi tube, a negative pressure environment is created at the maximum flow rate, passively dissolving air to form cavitation bubbles. Pressure then rapidly recovers, causing the bubbles to rupture and release energy, producing the hydrodynamic cavitation effect.

[0048] Example 2:

[0049] like Figure 3The difference from Example 1 is that in Example 2, the filtration module includes an inclined plate filter 10, which includes a dosing chamber 101 and a settling chamber 102. The dosing chamber 101 and the settling chamber 102 are connected at the bottom. The dosing chamber 101 is connected to the raw water collection tank 1 and is equipped with an agitator. A small amount of coagulant (100-500 mg / L PAC, 2-5 mg / L PAM) is added to the dosing chamber 101 and mixed uniformly. The settling chamber 102 is equipped with an inclined plate inside and a slag discharge port 103 at the bottom. The settling chamber 102 is provided with a clean liquid outlet. The clean liquid outlet is connected to the cavitation tank 6 of the cavitation skimming module. The slag discharge port 103 is connected to the plate-and-frame filter press 4. A liquid inlet pump 3 is connected between the slag discharge port 103 and the plate-and-frame filter press 4. The clean liquid pump 3 is a slurry pump. The filtrate outlet of the plate-and-frame filter press is connected to the raw water collection tank 1.

[0050] like Figure 3 The coagulated fracturing flowback fluid rapidly settles and stratifies in the sedimentation chamber 102. The lower layer of solid slag is pumped through the slag discharge port 103 to the plate and frame filter press for further extrusion and dehydration, resulting in a relatively dry solid slag. The filtrate from the plate and frame filter press is then introduced into the raw water collection tank 1.

[0051] like Figure 3 The cavitation tank 6 is provided with an outlet pipe, which is also connected to a precision filter 12 or a membrane filtration system. Through the precision filter or membrane filtration system, it can adapt to higher treatment standards in different oil fields and different regions. The outlet pipe after precision filtration is also equipped with an online monitoring sensor 13 to monitor the particulate matter content, oil content, and COD online.

[0052] The raw water collection tank 1 and the first floating oil separation device 2 serve as the raw water collection end and are located in the oilfield area. Other equipment is designed as an integrated skid-mounted structure, and the raw water collection end and the skid-mounted structure are connected by pipelines. In Example 1, the skid-mounted structure includes an inlet pump 3, a plate and frame filter press 4, an outlet pump 5, a cavitation tank 6, a hydrodynamic cavitation generator 7, an ozone generator 8, a second floating oil separation device 9, and a fan 11. In Example 2, the skid-mounted structure includes an inlet pump 3, a plate and frame filter press 4, an outlet pump 5, a cavitation tank 6, a hydrodynamic cavitation generator 7, an ozone generator 8, a second floating oil separation device 9, an inclined plate filter 10, and a fan 11.

[0053] The integrated skid-mounted structure facilitates equipment transport and facilitates fracturing flowback fluid processing operations in various oil fields. This system features a small size and good mobility. The entire equipment is skid-mounted and has dimensions no larger than 5.69 x 2.13 x 2.18 m.

[0054] The utility model provides an oilfield fracturing flowback fluid treatment method using the oilfield fracturing flowback fluid treatment system of Example 1, the method comprising:

[0055] A1. On the liquid surface of the collection tank, the wastewater raw water is preliminarily skimmed using an oil separation device.

[0056] A2. The wastewater after preliminary oil removal is introduced into the plate and frame filter press, and the filtrate after plate and frame filtration is then introduced into the cavitation tank; in the cavitation tank, hydraulic cavitation and ozone oxidation treatment are carried out.

[0057] A3. After cavitation and ozone treatment, the oil-water interface in the filtrate is broken, small oil droplets collide to form large oil droplets that further float up, and the floating oil is introduced into the floating oil separation device for further separation. The miscellaneous oil and other organic matter still in the water are oxidized; hydraulic cavitation and ozone oxidation treatment releases the gas in the fracturing return fluid, and the gas is collected by a fan.

[0058] A4. After the hydraulic cavitation and ozone oxidation treatment, the fracturing flowback fluid is led out of the precision filter or membrane filtration system to adapt to the higher treatment standards of different oil fields and different regions.

[0059] The utility model provides an oilfield fracturing flowback fluid treatment method using the oilfield fracturing flowback fluid treatment system of Example 2, the method comprising:

[0060] A1. On the liquid surface of the collection tank, the wastewater raw water is preliminarily skimmed using an oil separation device.

[0061] A2. The wastewater raw water after preliminary oil removal is introduced into the inclined plate filter. Coagulant (100-500 mg / L PAC, 2-5 mg / L PAM) is added to the dosing chamber of the inclined plate filter. The coagulated liquid enters the sedimentation chamber of the inclined plate filter. The upper clear liquid in the sedimentation chamber is introduced into the cavitation tank for hydrodynamic cavitation and ozone oxidation treatment. The residue liquid in the sedimentation chamber of the inclined plate filter is introduced into the plate and frame filter press. After further dehydration by the plate and frame, the filtrate is then introduced into the raw water collection tank. The filter residue is collected.

[0062] A3. After cavitation and ozone treatment, the oil-water interface in the filtrate is broken, small oil droplets collide to form large oil droplets that further float up, and the floating oil is introduced into the floating oil separation device for further separation. The remaining miscellaneous oil and other organic matter in the water are oxidized; hydraulic cavitation and ozone oxidation treatment releases the gas in the fracturing return fluid, and the gas is collected by a fan.

[0063] A4. After the hydraulic cavitation and ozone oxidation treatment, the fracturing flowback fluid is led out of the precision filter or membrane filtration system to adapt to the higher treatment standards of different oil fields and different regions.

[0064] The following further describes the oilfield fracturing flowback fluid processing system and method in combination with experimental data, but they should not be understood as limiting the scope of protection of the utility model.

[0065] A fracturing flowback water sample from an oil well was tested with a test fluid volume of 50L. The experimental steps are as follows:

[0066] (1) Place the wastewater into the stock solution pool and let it stand for 15 minutes. Open the first-level floating oil collector and collect the floating oil on the surface of the agent into the oil storage barrel.

[0067] (2) The water sample after the first oil removal is introduced into the coagulation sedimentation tank through a liquid transfer pump, and 500 mg / L PAC and 5 mg / L PAM are added. The reaction and sedimentation are carried out for 10 minutes. The upper clear liquid is discharged into the circulation tank, and the lower water sludge is discharged into the filter press.

[0068] (3) All the coagulated and precipitated sludge is introduced into the filter press for filtration operation. The clear liquid filtered out is discharged back into the original liquid pool, and the waste residue filtered out is collected separately.

[0069] (4) After the clear liquid of coagulation and sedimentation is collected in the circulation pool, the cavitation and ozone equipment are turned on at the same time. After reacting for 5 minutes, it is allowed to stand for 15 minutes.

[0070] (5) Open the secondary oil collector, remove the oil on the surface of the cavitation ozone treatment liquid after it has been allowed to stand, and then discharge it.

[0071] The experiments also included comparative tests between the cavitation treatment alone and the cavitation ozone treatment in Example 1, and the filter press filtration alone in Example 1 and the coagulation sedimentation-filter press filtration in Example 2. The treatment results for fracturing flowback water corresponding to the experimental schemes are shown in the table.

[0072] Experimental plan COD (mg / L) Oil content (mg / L) Particulate matter (mg / L) Fracturing flowback water sample before treatment 67537 66496 15322 Fracturing return water after single cavitation treatment in step 1 357.2 255.7 23.43 Fracturing return water after cavitation ozone treatment in step 1 41.1 2.19 25.64 Fracturing return water after coagulation sedimentation-filter pressure filtration treatment in step 2 37.20 1.57 21.63

[0073] Based on the experimental data above, Example 2 achieved the best treatment effect. While the fracturing flowback treated by the system in Example 1 also met discharge standards, the amount of water filtered by the filter press was 21 times greater than that of Example 2, which first underwent coagulation and sedimentation followed by fracturing filtration. This significantly increased the investment and process costs of the filter press. The solution in Example 1 can serve as an alternative in situations where the addition of a coagulant is not permitted on-site.

[0074] The above are only specific embodiments of the present invention, but the technical features of the present invention are not limited thereto. Any simple changes, equivalent substitutions, or modifications based on the present invention that solve essentially the same technical problems and achieve essentially the same technical effects are included within the scope of protection of the present invention.

Claims

1. Oilfield fracturing flowback fluid processing system, characterized by: include: Raw water collection pool, storing fracturing flowback fluid generated during oilfield production; A filtration module connected to the raw water collection tank; a cavitation skimming module connected to the filtration module, wherein the cavitation skimming module includes a hydraulic cavitation generating device; A first floating oil collector is provided on the liquid surface of the raw water collection tank. The first floating oil collector is connected to a first floating oil separation device. The first floating oil separation device is connected to the raw water collection tank.

2. The oilfield fracturing flowback fluid processing system according to claim 1, characterized in that: The filtration module is a plate-and-frame filter press, and a liquid inlet pump is connected between the plate-and-frame filter press and the raw water collection tank; and a liquid outlet pump is connected between the plate-and-frame filter press and the cavitation skimming module.

3. The oilfield fracturing flowback fluid processing system according to claim 1, characterized in that: The cavitation skimming module includes: a cavitation tank connected to the hydrodynamic cavitation generating device, and a booster pump connected between the hydrodynamic cavitation generating device and the cavitation tank; A partition is provided in the middle of the cavitation tank, which divides the cavitation tank into a treatment tank and a degreasing tank; The liquid inlet of the hydrodynamic cavitation generating device is connected to the oil removal tank, and the liquid outlet of the hydrodynamic cavitation generating device is connected to the treatment tank.

4. The oilfield fracturing flowback fluid processing system according to claim 3, characterized in that: The cavitation skimming module further comprises: An ozone generator is connected to the treatment tank, and an air distribution pipe of the ozone generator is provided in the treatment tank.

5. The oilfield fracturing flowback fluid processing system according to claim 3, characterized in that: The distance between the partition and the bottom of the cavitation tank is greater than zero, and an overflow port is provided on the partition; the width of the treatment tank is smaller than that of the degreasing tank.

6. The oilfield fracturing flowback fluid processing system according to claim 3, characterized in that: The cavitation pool is connected to a second floating oil separation device, a second floating oil collector is provided on the liquid surface of the degreasing tank, the second floating oil collector is connected to the second floating oil separation device; and the second floating oil separation device is connected to the treatment tank.

7. The oilfield fracturing flowback fluid processing system according to claim 3, characterized in that: A collection hood is provided above the cavitation pool, and the collection hood is connected to a gas collection device; a gas outlet is provided on the collection hood; the gas collection device includes a fan, the fan suction port is connected to the gas outlet, and the fan outlet is connected to a collection pipeline.

8. The oilfield fracturing flowback fluid processing system according to claim 1, characterized in that: The filtration module includes an inclined plate filter, which includes a dosing chamber and a sedimentation chamber. The dosing chamber is connected to the raw water collection tank. A slag discharge port is provided below the sedimentation chamber, and a clean liquid outlet is provided above the sedimentation chamber. The clean liquid outlet is connected to the cavitation skimming module.

9. The oilfield fracturing flowback fluid processing system according to claim 8, characterized in that: The slag discharge port is connected to a plate-frame filter press, a liquid inlet pump is connected between the plate-frame filter press and the slag discharge port, and the plate-frame filter press is connected to the raw water collection tank.

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