Multi-process test system and test method for oil and gas field produced water treatment

Abstract

The application discloses an oil and gas field produced water treatment multi-process test system, which comprises a raw water tank, a closed water inlet device, a main process reactor and a shared supporting device. The main process reactor comprises a micro-electrolysis reactor, a flocculation reactor, a gas floatation processor, a biological processor, an SSF tank and an ultrafiltration membrane filter. The application can realize the test of different processes in one set of water treatment multi-process test system. The application also discloses an oil and gas field produced water treatment multi-process test method. The oil and gas field produced water treatment multi-process test system is applied to various processes, such as chemical sedimentation, biochemistry, gas floatation, suspended sludge, electro-oxidation and advanced treatment processes, such as filtration and membrane filtration, and can cover the main process of oil and gas field produced water treatment. The main process simulation and auxiliary module can be flexibly combined to form various complete processes, thereby providing a test method for determining the complex oil field produced water treatment process.

Description

Technical Field

[0001] This invention belongs to the field of oil and gas field water treatment technology, and relates to a multi-process test system for oil and gas field produced water treatment, as well as a multi-process test method for oil and gas field produced water treatment. Background Technology

[0002] Produced water from oil and gas fields is complex in quality and varies greatly regionally, characterized by high corrosivity (low pH, high salinity), a significant tendency to scale, and unstable oil content. Due to the significant regional variations in water quality, the selection of produced water treatment processes during oil and gas field surface construction is correspondingly more challenging, while safety and environmental protection requirements are becoming increasingly stringent. Therefore, the applicability and precision of water treatment system design are particularly important. Currently, most water treatment test facilities are single-process test facilities. With crude oil extraction moving towards binary and ternary hydrodynamics, the quality of produced water from oil fields is becoming increasingly complex, and the treatment difficulty is gradually increasing. Single-process test facilities cannot meet the evaluation and selection needs of multiple processes, and their experimental accuracy is low. Furthermore, the cost of repeatedly constructing test facilities is high, they occupy a large area, and it is difficult to achieve parallel comparisons between multiple processes. Summary of the Invention

[0003] The purpose of this invention is to provide a multi-process test system for oil and gas field produced water treatment, which can realize the testing of different processes in one water treatment multi-process test system.

[0004] Another objective of this invention is to provide a multi-process test method for producing water treatment in oil and gas fields, enabling the testing of different processes within a single multi-process water treatment test system, thereby providing experimental means for determining the production water treatment process for complex oil fields.

[0005] The first technical solution adopted in this invention is a multi-process test system for oil and gas field produced water treatment, including a raw water tank, a closed water inlet, a main process reactor and common supporting devices. The main process reactor includes a micro-electrolysis reactor, a flocculation reactor, an air flotation processor, a biological processor, an SSF pool and an ultrafiltration membrane filter.

[0006] The invention is further characterized in that,

[0007] The raw water tank is equipped with a water quality predictor, which is a 2-meter-high water quality sedimentation column. Multiple sampling ports are set at different heights of the water quality sedimentation column. The upper and middle parts of the raw water tank are respectively equipped with a high-level oil collection tank and a bottom-level sludge discharge tank.

[0008] The shared supporting equipment includes an inlet booster pump, an intermediate booster pump, a dosing device, and pipelines. The inlet booster pump is connected to the raw water tank through a sealed inlet device, which includes an inlet pipe, a sealing cap, an inlet valve, and a quick-connect port. One end of the inlet pipe is inserted into the raw water tank, and a sealing cap is installed where the inlet pipe is inserted into the raw water tank. An inlet valve is installed on the inlet pipe, and the other end of the inlet pipe is connected to the inlet booster pump through a quick-connect port. The dosing device is connected to the flocculation reactor.

[0009] The micro-electrolysis reactor includes an oxidation tank and a micro-electrolysis cell. The oxidation tank is connected to an intermediate booster pump, and the micro-electrolysis cell is connected to an inlet booster pump. An aeration pipe a is installed at the bottom of the micro-electrolysis cell, and an aeration pipe b is installed at the bottom of the oxidation tank. Aeration pipe a and aeration pipe b are connected to an aeration pump. The oxidation tank is connected to the top of the micro-electrolysis cell.

[0010] The dosing device includes multiple dosing pumps, each of which is connected to a dosing tank. One dosing pump is connected to an oxidation tank, another dosing pump is connected to a raw water tank, and yet another dosing pump is connected to a flocculation reactor.

[0011] The flocculation reactor includes a PAC coagulation tank and a PAM coagulation tank. The top of the PAC coagulation tank and the bottom of the PAM coagulation tank are connected by a pipeline. The bottom of the PAC coagulation tank is connected to a dosing pump and an intermediate booster pump, respectively. A dosing pump is connected to the pipeline connecting the PAC coagulation tank and the PAM coagulation tank.

[0012] The dissolved air flotation (DAF) processor includes a DAF tank, which is connected to the top of the PAM coagulation tank via a pipe. The DAF tank is equipped with a sludge scraper motor and a dissolved air pump. A sludge discharge pipe is installed at the bottom of the DAF tank, and a clear water pipe is installed at the top. A clear water tank and a sludge tank are installed below the DAF tank. The dissolved air pump is connected to the clear water tank, the outlet of the clear water pipe extends into the clear water tank, and the outlet of the sludge discharge pipe extends into the sludge tank.

[0013] An ultrafiltration membrane filter includes an ultrafiltration membrane device. The inlet pipe of the ultrafiltration membrane device is connected to a pre-membrane water tank via an ultrafiltration membrane booster pump. A concentrate outlet pipe is also connected to the pre-membrane water tank, with the outlet end of the concentrate outlet pipe extending into the pre-membrane water tank. The outlet pipe of the ultrafiltration membrane device is connected to an ultrafiltration membrane backwash pump and a post-membrane water tank via pipes. The ultrafiltration membrane backwash pump is connected to the post-membrane water tank via pipes.

[0014] The biological processor includes an electrical control box and, in sequence, a heating and regulating tank, a primary biological reactor, a secondary biological reactor, a tertiary biological reactor, an inclined plate sedimentation tank, and a clear water tank. The primary, secondary, and tertiary biological reactors are connected to wastewater lift pumps, and the clear water tank is connected to a clear water pump. The electrical control box is connected to the primary, secondary, and tertiary biological reactors respectively. The inlet of the heating and sedimentation tank is connected to the clear water pipe via a pipe, and the outlet is connected to the pre-membrane water tank via a pipe. The top outlet of the SSF tank is connected to the pre-membrane water tank via a pipe.

[0015] The second technical solution adopted in this invention is a multi-process test method for treating produced water from oil and gas fields. The multi-process test system of this invention is used to conduct experiments, and the following test processes are performed for different types of produced water from oil fields:

[0016] 1) For oilfield produced water with unknown water quality, the settling performance of the water is first determined by a water quality predictor. If the settling performance is good, gravity settling is performed in a raw water tank, followed by flocculation and settling treatment in a flocculation reactor, and then deep filtration through an ultrafiltration membrane filter to complete the oilfield produced water treatment test. If the settling performance is poor, air flotation treatment is performed in sequence, followed by suspended sludge treatment in an air flotation processor or an SSF tank, and then deep filtration through an ultrafiltration membrane filter to complete the oilfield produced water treatment test.

[0017] 2) For oilfield produced water containing polymers in binary and ternary flooding oil production modes, the polymers in the produced water affect the oil removal and suspended solids removal effects. First, the sedimentation performance of the water quality is judged by a water quality predictor. Then, micro-electrolysis demulsification treatment is carried out in sequence using a micro-electrolysis reactor, biochemical oil removal treatment is carried out using a biological processor, and flocculation sedimentation is carried out using a flocculation reactor to remove suspended solids, thus completing the oil and gas field produced water treatment test.

[0018] 3) For oilfield produced water that needs to meet the standards for reuse or discharge, the sedimentation performance of the water is first determined by a water quality predictor, and then it is sequentially treated by an air flotation processor and a deep filtration process by an ultrafiltration membrane filter to complete the oil and gas field produced water treatment test.

[0019] The invention is further characterized in that,

[0020] When a water quality predictor assesses the settling performance of water, if a clear solid-liquid stratification interface is visually observed within a specified settling time, it indicates that the settling performance of the produced water from the oilfield is good; conversely, if the interface is not visible, the settling performance of the produced water from the oilfield is poor.

[0021] The beneficial effects of this invention are:

[0022] This invention is a multi-process test system for producing water treatment in oil and gas fields, which includes different main process reactors. Different main process reactors can constitute different process modules. For complex water quality tests of produced water in different oil and gas fields, the tests can be completed by combining the process modules, which has high test efficiency and effectively reduces test costs.

[0023] This invention is a multi-process experimental method for treating produced water in oil and gas fields. It utilizes a multi-process experimental system for producing water treatment in oil and gas fields. Because the multi-process experimental system for producing water treatment in oil and gas fields contains a variety of different process modules, including chemical sedimentation, biochemical treatment, air flotation, suspended sludge, electro-oxidation and other processes, as well as advanced treatment processes such as filtration and membrane filtration, it can cover the main processes of producing water treatment in oil and gas fields. The main process simulation and auxiliary modules can be flexibly combined to form a variety of complete processes. In addition to being used for the selection, simulation, evaluation and optimization of producing water treatment processes in oil and gas fields through experiments, it can also be widely applied to research on the simulation and evaluation of water treatment processes in non-oil and gas field industries. This provides convenience for the design, optimization and transformation of water treatment processes in various industries. Attached Figure Description

[0024] Figure 1 This is a schematic diagram of the multi-process test system for oil and gas field produced water treatment according to the present invention;

[0025] Figure 2 This is a flowchart of the multi-process experimental method for treating produced water in oil and gas fields according to the present invention.

[0026] In the diagram, 1. Raw water tank, 2. High-level oil collection tank, 3. Bottom-level sludge discharge tank, 4. Inlet water lift pump, 5. Aeration pump, 6. Intermediate lift pump, 7. Micro-electrolysis cell, 8. Oxidation tank, 9. Aeration pipe a, 10. Aeration pipe b, 11. Dosing pump, 12. Dosing tank, 13. PAC coagulation tank, 14. PAM coagulation tank, 15. Air flotation tank, 16. Sludge scraper motor, 17. Dissolved air pump, 18. Clear water tank. 19. Sludge tank; 20. Electrical control box; 21. Heating and equalization tank; 22. Primary biological reactor; 23. Secondary biological reactor; 24. Tertiary biological reactor; 25. Inclined plate sedimentation tank; 26. Clear water tank; 27. SSF tank; 28. Ultrafiltration membrane equipment; 29. ​​Ultrafiltration membrane lift pump; 30. Pre-membrane water tank; 31. Concentrate effluent pipe; 32. Ultrafiltration membrane backwash pump; 33. Post-membrane water tank. Detailed Implementation

[0027] The present invention will now be described in detail with reference to the accompanying drawings and specific embodiments.

[0028] Example 1

[0029] This embodiment provides a multi-process test system for oil and gas field produced water treatment, including a raw water tank 1, a closed water inlet, a main process reactor, and common supporting devices. The raw water tank 1 is equipped with a water quality predictor and a level gauge. The water quality predictor is a 2-meter-high water quality sedimentation column. Multiple sampling ports are set at different heights of the water quality sedimentation column. The upper and middle parts of the raw water tank 1 are respectively equipped with a high-level oil collection tank 2 and a bottom-level oil collection tank 3.

[0030] The main process reactors include a micro-electrolysis reactor, a flocculation reactor, an air flotation processor, a biological processor, an SSF tank 27, and an ultrafiltration membrane filter.

[0031] The shared supporting equipment includes an inlet booster pump 4, an intermediate booster pump 6, a dosing device, and pipelines. The inlet booster pump 4 is connected to the raw water tank 1 through a sealed inlet device. The sealed inlet device includes an inlet pipe, a sealing cap, an inlet valve, and a quick-connect pipe port. One end of the inlet pipe is inserted into the raw water tank 1, and a sealing cap is provided at the point where the inlet pipe is inserted into the raw water tank 1. An inlet valve is provided on the inlet pipe. The other end of the inlet pipe is connected to the inlet booster pump 4 through a quick-connect pipe port. The dosing device is connected to the flocculation reactor.

[0032] Example 2

[0033] This embodiment provides a multi-process experimental system for treating produced water in oil and gas fields, such as... Figure 1 As shown, based on Example 1, the micro-electrolysis reactor includes an oxidation tank 8 and a micro-electrolysis cell 7. The oxidation tank 8 is connected to an intermediate booster pump 6, and the micro-electrolysis cell 7 is connected to an inlet booster pump 4. An aeration pipe a9 is provided at the bottom of the micro-electrolysis cell 7, and an aeration pipe b10 is provided at the bottom of the oxidation tank 8. An aeration pump 5 is connected to the aeration pipe a9 and the aeration pipe b10. The oxidation tank 8 is connected to the top of the micro-electrolysis cell 7.

[0034] The dosing device includes multiple dosing pumps 11, each dosing pump 11 is connected to a dosing tank 12, one dosing pump 11 is connected to an oxidation tank 8, one dosing pump 11 is connected to a raw water tank 1, and another dosing pump 11 is connected to a flocculation reactor.

[0035] The flocculation reactor includes a PAC coagulation tank 13 and a PAM coagulation tank 14. The top of the PAC coagulation tank 13 and the bottom of the PAM coagulation tank 14 are connected by a pipe. The bottom of the PAC coagulation tank 13 is connected to a dosing pump 11 and an intermediate booster pump 6, respectively. A dosing pump 11 is connected to the pipe connecting the PAC coagulation tank 13 and the PAM coagulation tank 14.

[0036] The dissolved air flotation (DAF) processor includes a DAF tank 15, which is connected to the top of a PAM coagulation tank 14 via a pipe. A pressure gauge (0-0.6 MPa) is installed near the outlet of the PAM coagulation tank 14. The DAF tank 15 is equipped with a scraper motor 16 and a dissolved air pump 17. A sludge discharge pipe is installed at the bottom of the DAF tank 15, and a clear water pipe is installed at the top. A clear water tank 18 and a sludge tank 19 are installed below the DAF tank 15. The dissolved air pump 17 is connected to the clear water tank 18, and a level gauge is installed in the clear water tank 18. The outlet of the clear water pipe extends into the clear water tank 18, and the outlet of the sludge discharge pipe extends into the sludge tank 19.

[0037] The ultrafiltration membrane filter includes an ultrafiltration membrane device 28. The inlet pipe of the ultrafiltration membrane device 28 is connected to a pre-membrane water tank 30 via an ultrafiltration membrane booster pump 29. A level gauge is installed in the pre-membrane water tank 30. A concentrate outlet pipe 31 is also connected to the membrane of the ultrafiltration membrane device 28. The outlet end of the concentrate outlet pipe 31 extends into the pre-membrane water tank 30. The outlet pipe of the ultrafiltration membrane device 28 is connected to an ultrafiltration membrane backwash pump 32 and a post-membrane water tank 33 via pipes. The ultrafiltration membrane backwash pump 32 is connected to the post-membrane water tank 33 via a pipe.

[0038] The biological processor includes an electrical control box 20 and a heating and regulating tank 21, a primary biological reactor 22, a secondary biological reactor 23, a tertiary biological reactor 24, an inclined plate sedimentation tank 25, and a clear water tank 26 arranged sequentially. The primary biological reactor 22, the secondary biological reactor 23, and the tertiary biological reactor 24 are connected to wastewater lift pumps, and the clear water tank is connected to a clear water pump. The electrical control box is connected to the primary biological reactor 22, the secondary biological reactor 23, and the tertiary biological reactor 24 respectively. The inlet of the heating and sedimentation tank 21 is connected to the clear water pipe through a pipe, and the outlet is connected to the pre-membrane water tank 30 through a pipe. The top outlet of the SSF tank is connected to the pre-membrane water tank through a pipe.

[0039] Example 3

[0040] This embodiment provides a multi-process test method for treating produced water from oil and gas fields. The multi-process test system from Embodiment 2 is used to test produced water from oil fields with unknown water quality. The specific test process is as follows:

[0041] First, the settling performance of the water is determined using a water quality predictor. If a clear solid-liquid stratification interface is visually observed within a specified settling time, the oilfield produced water has good settling performance; conversely, if not, the settling performance is poor. When the settling performance is good, gravity settling is performed in raw water tank 1, followed by flocculation and settling in a flocculation reactor, and then deep filtration through an ultrafiltration membrane filter to complete the oilfield produced water treatment test. When the settling performance is poor, air flotation treatment is performed sequentially using an air flotation processor, or suspended sludge treatment is performed in SSF tank 27, followed by deep filtration through an ultrafiltration membrane filter to complete the oilfield produced water treatment test.

[0042] Example 4

[0043] This embodiment provides a multi-process test method for treating produced water from oil and gas fields. The multi-process test system from Embodiment 2 is used to test produced water from oil fields containing polymers in binary and ternary flooding oil recovery modes. The specific test process is as follows:

[0044] Since the produced water from oilfields produced in binary and ternary oil recovery modes contains polymers, which affect the oil removal and suspended solids removal effects, the sedimentation performance of the water was first determined by a water quality predictor. Then, a micro-electrolysis reactor was used for micro-electrolysis demulsification treatment, a biological processor was used for biochemical oil removal treatment, and a flocculation reactor was used for flocculation sedimentation to remove suspended solids, thus completing the oil and gas field produced water treatment experiment.

[0045] Example 5

[0046] This embodiment provides a multi-process test method for treating produced water from oil and gas fields. The multi-process test system from Embodiment 2 is used to test produced water from oil fields that needs to meet reuse or discharge standards. The specific test process is as follows:

[0047] First, the settling properties of the water are determined by a water quality predictor. Then, the water is subjected to flotation treatment by an air flotation processor and deep filtration by an ultrafiltration membrane filter to complete the oil and gas field produced water treatment test.

[0048] Following the multi-process test method for oil and gas field produced water treatment described above, a process evaluation was conducted. This evaluation included selecting process modules to form a complete pilot-scale process flow; the pilot-scale run time should be no less than three times the unit volume circulation rate; sampling during operation should cover all sections, with no less than six samples taken at each sampling point, at intervals of 0.5–2 hours; the number of samples can be increased for critical control points; monitoring indicators should include at least operational parameters such as flow rate, pH, and dissolved oxygen, as well as treatment effect control indicators such as suspended solids, petroleum hydrocarbon content, and median particle diameter; data analysis was performed based on the monitoring results, including at least section removal rate, overall removal rate, and single-point data repetition rate calculations.

[0049] As can be seen from the above, the present invention provides a multi-process experimental method for treating produced water in oil and gas fields, such as... Figure 2 As shown, the system encompasses various processes including chemical sedimentation, biochemical treatment, air flotation, suspended sludge treatment, and electro-oxidation, as well as advanced treatment processes such as filtration and membrane filtration. It covers the main processes for treating produced water from oil and gas fields. The main process simulation and auxiliary modules can be flexibly combined to form various complete processes. To determine more adaptable water treatment processes, a multi-process experimental evaluation method is used to form candidate processes. Comparative simulations are conducted for specific water qualities, while monitoring and controlling indicators, and analyzing the treatment effects to provide a basis for selecting the process with superior indicators in various aspects. Furthermore, the treatment effect and adaptability can be evaluated, and process optimization suggestions can be given. Moreover, through experimental evaluation and simulation, the advantages and disadvantages of the processes can be clearly understood, and the optimal operating technical parameters under specific water quality conditions can be determined, providing a foundation for the promotion and application of new processes.

Claims

1. A multi-process experimental system for treating produced water in oil and gas fields, characterized in that, It includes a raw water tank (1), a sealed water inlet, a main process reactor and common supporting devices. The main process reactor includes a micro-electrolysis reactor, a flocculation reactor, an air flotation processor, a biological processor, an SSF tank (27) and an ultrafiltration membrane filter. The raw water tank (1) is equipped with a water quality predictor, which is a 2-meter-high water quality sedimentation column. The water quality sedimentation column has multiple sampling ports at different heights. The upper and middle parts of the raw water tank (1) are respectively equipped with a high-level oil collection tank (2) and a bottom-level oil collection tank (3). The common supporting equipment includes an inlet booster pump (4), an intermediate booster pump (6), a dosing device and pipelines. The inlet booster pump (4) is connected to the raw water tank (1) through a sealed inlet device. The sealed inlet device includes an inlet pipe, a sealing cover, an inlet valve and a quick-connect pipe port. One end of the inlet pipe is inserted into the raw water tank (1), and a sealing cover is provided at the point where the inlet pipe is inserted into the raw water tank (1). An inlet valve is provided on the inlet pipe. The other end of the inlet pipe is connected to the inlet booster pump (4) through a quick-connect pipe port. The dosing device is connected to the flocculation reactor. The micro-electrolysis reactor includes an oxidation tank (8) and a micro-electrolysis cell (7). The oxidation tank (8) is connected to an intermediate booster pump (6), and the micro-electrolysis cell (7) is connected to an inlet booster pump (4). An aeration pipe a (9) is provided at the bottom of the micro-electrolysis cell (7), and an aeration pipe b (10) is provided at the bottom of the oxidation tank (8). An aeration pump (5) is connected to the aeration pipe a (9) and the aeration pipe b (10). The oxidation tank (8) is connected to the top of the micro-electrolysis cell (7).

2. The multi-process experimental system for treating produced water in oil and gas fields according to claim 1, characterized in that, The dosing device includes multiple dosing pumps (11), each of which is connected to a dosing tank (12). One of the dosing pumps (11) is connected to an oxidation tank (8), another of the dosing pumps (11) is connected to a raw water tank (1), and yet another of the dosing pumps (11) is connected to a flocculation reactor. The flocculation reactor includes a PAC coagulation tank (13) and a PAM coagulation tank (14). The top of the PAC coagulation tank (13) and the bottom of the PAM coagulation tank (14) are connected by a pipe. The bottom of the PAC coagulation tank (13) is connected to a dosing pump (11) and an intermediate lift pump (6) respectively. A dosing pump (11) is connected to the pipe connecting the PAC coagulation tank (13) and the PAM coagulation tank (14).

3. The multi-process experimental system for treating produced water in oil and gas fields according to claim 2, characterized in that, The flotation processor includes a flotation tank (15), which is connected to the top of a PAM coagulation tank (14) via a pipe. The flotation tank (15) is equipped with a sludge scraper motor (16) and a dissolved air pump (17). The flotation tank (15) has a sewage pipe at the bottom and a clean water pipe at the top. A clean water tank (18) and a sludge tank (19) are located below the flotation tank (15). The dissolved air pump (17) is connected to the clean water tank (18). The outlet of the clean water pipe extends into the clean water tank (18), and the outlet of the sewage pipe extends into the sludge tank (19).

4. The multi-process experimental system for treating produced water in oil and gas fields according to claim 3, characterized in that, The ultrafiltration membrane filter includes an ultrafiltration membrane device (28). The inlet pipe of the ultrafiltration membrane device (28) is connected to a pre-membrane water tank (30) via an ultrafiltration membrane lift pump (29). The ultrafiltration membrane device (28) is also connected to a concentrate outlet pipe (31) in front of the membrane. The outlet end of the concentrate outlet pipe (31) extends into the pre-membrane water tank (30). The outlet pipe of the ultrafiltration membrane device (28) is connected to an ultrafiltration membrane backwash pump (32) and a post-membrane water tank (33) via pipes. The ultrafiltration membrane backwash pump (32) is connected to the post-membrane water tank (33) via pipes.

5. The multi-process experimental system for treating produced water in oil and gas fields according to claim 4, characterized in that, The biological processor includes an electrical control box (20) and a heating and regulating tank (21), a primary biological reactor (22), a secondary biological reactor (23), a tertiary biological reactor (24), an inclined plate sedimentation tank (25), and a clear water tank (26) arranged in sequence. The primary biological reactor (22), the secondary biological reactor (23), and the tertiary biological reactor (24) are connected to wastewater lift pumps. The clear water tank is connected to a clear water pump. The electrical control box is connected to the primary biological reactor (22), the secondary biological reactor (23), and the tertiary biological reactor (24) respectively. The inlet of the heating and regulating tank (21) is connected to the clear water pipe through a pipe, and the outlet is connected to the pre-membrane water tank (30) through a pipe. The top outlet of the SSF tank (27) is connected to the pre-membrane water tank through a pipe.

6. A multi-process test method for treating produced water in oil and gas fields, wherein the multi-process test system described in claim 1 is used for testing, characterized in that, The following experimental procedures were conducted for produced water from different oilfields: 1) For oilfield produced water with unknown water quality, the sedimentation performance of the water is first determined by the water quality predictor. If the sedimentation performance is good, gravity sedimentation is carried out in the raw water tank (1), followed by flocculation sedimentation treatment in the flocculation reactor, and then deep treatment filtration is carried out through the ultrafiltration membrane filter to complete the oil and gas field produced water treatment test. If the sedimentation performance is poor, air flotation treatment is carried out in sequence by the air flotation processor or suspended sludge treatment in the SSF tank (27), and then deep treatment filtration is carried out through the ultrafiltration membrane filter to complete the oil and gas field produced water treatment test. 2) For oilfield produced water containing polymers in binary and ternary flooding oil production modes, the polymers in the produced water affect the oil removal and suspended solids removal effects. First, the sedimentation performance of the water quality is judged by a water quality predictor. Then, micro-electrolysis demulsification treatment is carried out in sequence using a micro-electrolysis reactor, biochemical oil removal treatment is carried out using a biological processor, and flocculation sedimentation is carried out using a flocculation reactor to remove suspended solids, thus completing the oil and gas field produced water treatment test. 3) For oilfield produced water that needs to meet the standards for reuse or discharge, the settling performance of the water is first determined by a water quality predictor, and then it is sequentially treated by an air flotation processor and a deep filtration process by an ultrafiltration membrane filter to complete the oil and gas field produced water treatment test.

7. The multi-process experimental method for treating produced water in oil and gas fields according to claim 6, characterized in that, When a water quality predictor assesses the settling performance of water, if a clear solid-liquid stratification interface is visually observed within a specified settling time, it indicates that the settling performance of the produced water from the oilfield is good; conversely, if the interface is not visible, the settling performance of the produced water from the oilfield is poor.

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