Oil field sewage treatment system and oil field sewage treatment method

Abstract

The invention discloses an oil field sewage treatment system and an oil field sewage treatment method.The oil field sewage treatment system comprises a pipeline, a plurality of sewage treatment devices and a control device, and the pipeline is provided with a water inlet, a water outlet and a purification flow path located between the water inlet and the water outlet; a plurality of feeding ports are formed in the side wall of the pipeline, a flow meter is arranged at a water inlet of the pipeline, and a plurality of metering pumps are arranged at the feeding ports in a one-to-one correspondence manner; the plurality of sewage treatment devices are arranged on the purification flow path in series; the control device is electrically connected with the flow meter and the metering pumps and used for controlling the flow of at least one metering pump according to the detection result of the flow meter. According to the technical scheme provided by the invention, automatic accurate metering and accurate adding of the medicament are realized, the consumption of the medicament is reduced while the sewage treatment system is ensured to stably reach the standard, and the operation cost of the system is reduced.

Description

Technical Field

[0001] The present invention relates to the technical field of sewage treatment, and particularly to an oilfield sewage treatment system and an oilfield sewage treatment method. Background Art

[0002] In the technical field of sewage treatment, in addition to the rationality of sewage treatment process design and the reliability of water treatment equipment design, the dosing system is often an important part of the sewage treatment system. Especially in a pure chemical sewage treatment system, the stability, reliability, and intelligence of the dosing system will directly affect the operation stability of the entire sewage treatment system, the compliance rate of the effluent quality of the sewage treatment system, and the chemical agent cost of the sewage treatment system. It can be seen that the dosing system is important in the sewage treatment process. Especially when the current environmental protection policies put forward high requirements for the stability and stable compliance rate of the sewage treatment system.

[0003] Currently, the dosing systems designed and used in sewage treatment systems generally adopt a relatively extensive dosing method, that is, after determining a specific chemical agent dosing amount through laboratory experimental analysis at a certain water volume, it belongs to a quantitative dosing method. That is, even when the influent water volume fluctuates, the dosing amount of the chemical agent remains unchanged, which often leads to the occurrence of the following two situations: one is that the dosing amount of the chemical agent is insufficient, and in this case, long-term operation results in the non-compliance of the effluent quality of the sewage treatment system; the other is that the dosing amount of the chemical agent is excessive, and in this case, long-term operation leads to a large amount of waste of various chemical agents and secondary chemical pollution caused by excessive dosing of chemical agents. Summary of the Invention

[0004] The main object of the present invention is to provide an oilfield sewage treatment system and an oilfield sewage treatment method, aiming to achieve automatic precise metering and precise dosing of chemical agents, while ensuring the stable compliance of the sewage treatment system, reducing the consumption of chemical agents, and reducing the operating cost of the system.

[0005] To achieve the above object, an oilfield sewage treatment system proposed by the present invention includes a pipeline, a plurality of sewage treatment devices, and a control device. The pipeline has an inlet, an outlet, and a purification flow path located between the inlet and the outlet. A plurality of dosing ports are provided on the side wall of the pipeline, and a flow meter is provided at the inlet of the pipeline. A plurality of metering pumps are provided corresponding to the plurality of dosing ports one by one; the plurality of sewage treatment devices are connected in series on the purification flow path; the control device is electrically connected to the flow meter and the plurality of metering pumps respectively, and is used to control the flow rate of at least one of the metering pumps according to the detection result of the flow meter.

[0006] Optionally, the flow meter includes an electromagnetic flow meter; and / or, the metering pump includes a digital metering pump.

[0007] Optionally, the oilfield sewage treatment system further includes a water quality detection device disposed corresponding to the water outlet. The control device is electrically connected to the water quality detection device and is configured to control the flow rate of at least one of the metering pumps according to the detection result of the water quality detection device.

[0008] Optionally, the plurality of dosing ports are used for dosing demulsifier, bactericide, corrosion inhibitor, and water purifying agent. The water quality detection device includes an SS detector, a PH detector, and a conductivity monitor. The metering pumps include a plurality of first metering pumps respectively disposed corresponding to the plurality of dosing ports for dosing demulsifier, bactericide, and corrosion inhibitor, and a second metering pump disposed corresponding to the dosing port for dosing water purifying agent. The control device is configured to control the flow rate of the plurality of first metering pumps respectively according to the detection result of the flowmeter, and is configured to control the flow rate of the second metering pump according to the detection result of the SS detector.

[0009] Optionally, the plurality of sewage treatment devices include a three-phase separator, a settler, and a filter. On the purification flow path, the plurality of dosing ports include a first dosing port between the water inlet of the pipeline and the three-phase separator, a plurality of second dosing ports between the three-phase separator and the settler, and a third dosing port between the filter and the water outlet of the pipeline. The first dosing port is used for dosing demulsifier, the plurality of second dosing ports are respectively used for dosing bactericide, corrosion inhibitor, and water purifying agent, and the third dosing port is used for dosing bactericide.

[0010] Optionally, the control device includes a control module and a display module communicatively connected to the control module. The control module is communicatively connected to the flowmeter and the plurality of metering pumps respectively, and is configured to control the flow rate of at least one of the metering pumps according to the detection result of the flowmeter. The control module is further configured to obtain the flow rates of the plurality of metering pumps. The display module is configured to be communicatively connected to a display device and display the flow rates of the plurality of metering pumps obtained by the control module on the display device.

[0011] Optionally, the oilfield sewage treatment system further includes a plurality of medicine preparation devices disposed corresponding to the plurality of dosing ports. Each medicine preparation device includes a configuration tank, a stirrer, and a liquid level gauge. The configuration tank is provided with a water inlet, a medicine inlet, and a medicine outlet. The medicine outlet is communicated with the corresponding dosing port. Electric valves are provided at both the water inlet and the medicine inlet. The stirrer includes a stirring part extending into the configuration tank. The liquid level gauge is used for detecting the liquid level in the configuration tank.

[0012] Optionally, the material of the configuration box includes one of homopolypropylene (PPH), polypropylene (PP), and polyethylene (PE); and / or, the electric valve includes an explosion-proof electric butterfly valve; and / or, the mixer includes an explosion-proof paddle mixer; and / or, the liquid level gauge includes an explosion-proof and corrosion-proof magnetic flap liquid level gauge.

[0013] The present invention also provides an oilfield sewage treatment method based on the above-mentioned oilfield sewage treatment system. The oilfield sewage treatment method includes the following steps:

[0014] Obtain the detection result of the flowmeter;

[0015] According to the detection result of the flowmeter, control the flow rate of at least one of the metering pumps.

[0016] Optionally, the oilfield sewage treatment system further includes a water quality detection device arranged corresponding to the water outlet. The control device is electrically connected to the water quality detection device and is used to control the flow rate of at least one of the metering pumps according to the detection result of the water quality detection device. The oilfield sewage treatment method further includes the following steps:

[0017] Obtain the detection result of the water quality detection device;

[0018] According to the detection result of the water quality detection device, control the flow rate of at least one of the metering pumps.

[0019] In the technical solution of the present invention, the oilfield sewage treatment system includes a pipeline, a plurality of sewage treatment devices, and a control device. The pipeline has a water inlet, a water outlet, and a purification flow path located between the water inlet and the water outlet. A plurality of dosing ports are opened on the side wall of the pipeline. A flowmeter is provided at the water inlet of the pipeline, and a plurality of metering pumps are provided corresponding to the plurality of dosing ports one by one; the plurality of sewage treatment devices are connected in series on the purification flow path; the control device is electrically connected to the flowmeter and the plurality of metering pumps respectively, and is used to control the flow rate of at least one of the metering pumps according to the detection result of the flowmeter. In this way, the linkage adjustment of the dosing amount of the chemical agent and the water inflow of the sewage can be realized, and the accurate metering and accurate dosing of the chemical agent can be achieved, thereby avoiding the situation of insufficient dosing amount or excessive dosing amount of the chemical agent caused by the change of the water inflow. By controlling the flow rate of the metering pump through the control device, the labor intensity of the operator caused by manually adjusting the flow rate of the metering pump can be avoided, so as to realize the automatic and accurate metering and accurate dosing of the chemical agent, ensure the stable compliance of the sewage treatment system while reducing the consumption of the chemical agent and the operation cost of the system. Description of the Drawings

[0020] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the drawings required for the description of the embodiments or the prior art. Obviously, the drawings in the following description are only some embodiments of the present invention. For those of ordinary skill in the art, without creative efforts, other drawings can be obtained based on the structures shown in these drawings.

[0021] Figure 1 Schematic diagram of the principle of an embodiment of the oilfield sewage treatment system provided by the present invention;

[0022] Figure 2 For Figure 1 Schematic diagram of the structure of the chemical dosing device in

[0023] Figure 3 Schematic diagram of the process of an embodiment of the oilfield sewage treatment method provided by the present invention;

[0024] Figure 4 Schematic diagram of the process of another embodiment of the oilfield sewage treatment method provided by the present invention.

[0025] Explanation of the reference numerals in the drawings:

[0026] Label Name Label Name 100 Oilfield sewage treatment system 5 Water quality detection device 1 Flowmeter 6 Drug dispensing device 2 Metering pump 61 Configuration tank 3 Sewage treatment device 611 Water inlet 31 Three-phase separator 612 Drug addition port 32 Settler 613 Drug outlet 33 Filter 62 Agitator 4 Control device 63 Level gauge

[0027] The realization, functional characteristics, and advantages of the object of the present invention will be further described in conjunction with the embodiments and with reference to the drawings. Detailed implementation manners

[0028] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, rather than all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts belong to the scope of protection of the present invention.

[0029] It should be noted that if there are directional indications (such as up, down, left, right, front, back...) involved in the embodiments of the present invention, the directional indications are only used to explain the relative positional relationship and movement conditions between components in a specific posture (as shown in the drawings). If the specific posture changes, the directional indications will also change accordingly.

[0030] In addition, if descriptions such as "first" and "second" are involved in the embodiments of the present invention, the descriptions of "first", "second", etc. are only for descriptive purposes and should not be construed as indicating or implying their relative importance or implicitly specifying the quantity of the indicated technical features. Thus, features defined with "first" and "second" may explicitly or implicitly include at least one such feature. In addition, the meaning of "and / or" appearing throughout the text includes three parallel scenarios. Taking "A and / or B" as an example, it includes Scenario A, or Scenario B, or the scenario where both A and B are satisfied simultaneously. In addition, the technical solutions between various embodiments can be combined with each other, but it must be based on the ability of those of ordinary skill in the art to implement. When the combination of technical solutions results in contradictions or cannot be implemented, it should be considered that such a combination of technical solutions does not exist and is not within the scope of protection required by the present invention.

[0031] In the field of sewage treatment technology, in addition to the rationality of sewage treatment process design and the reliability of water treatment equipment design, the dosing system is often an important part of the sewage treatment system. Especially in a pure chemical sewage treatment system, the stability, reliability, and intelligence of the dosing system will directly affect the operation stability of the entire sewage treatment system, the compliance rate of the effluent quality of the sewage treatment system, and the chemical agent cost of the sewage treatment system. It can be seen the importance of the dosing system in the sewage treatment process. Especially under the current situation where environmental protection policies have put forward higher requirements for the stability and stable compliance rate of the sewage treatment system.

[0032] Currently, the dosing systems designed and used in sewage treatment systems generally adopt a relatively extensive dosing method, that is, after determining a specific chemical agent dosing amount through laboratory experimental analysis based on a certain amount of water, which belongs to a quantitative dosing method. That is, the dosing amount of the chemical agent remains fixed even when the influent water volume fluctuates, which often leads to the occurrence of the following two situations: one is that the dosing amount of the chemical agent is insufficient, and in this case, long-term operation results in the non-compliance of the effluent quality of the sewage treatment system; the other is that the dosing amount of the chemical agent is excessive, and in this case, long-term operation leads to a large waste of various chemical agents and secondary chemical pollution caused by excessive dosing of chemical agents.

[0033] In view of this, the present invention provides an oilfield sewage treatment system and an oilfield sewage treatment method, aiming to achieve automatic and accurate metering and accurate dosing of chemical agents, while ensuring the stable compliance of the sewage treatment system, reducing the consumption of chemical agents, and reducing the operating cost of the system. Figures 1 to 2 For the embodiment of the oilfield sewage treatment system provided by the present invention, Figures 3 to 4 For the embodiment of the oilfield sewage treatment method provided by the present invention.

[0034] In an embodiment of the present invention, referring to the accompanying drawings, the oilfield sewage treatment system 100 includes a pipeline, a plurality of sewage treatment devices 3, and a control device 4. The pipeline has a water inlet, a water outlet, and a purification flow path located between the water inlet and the water outlet. A plurality of dosing ports are provided on the side wall of the pipeline, and a plurality of metering pumps 2 are provided corresponding to the plurality of dosing ports one by one; the plurality of sewage treatment devices 3 are connected in series on the purification flow path; the control device 4 is electrically connected to the flow meter 1 and the plurality of metering pumps 2 respectively, and is configured to control the flow rate of at least one of the metering pumps 2 according to the detection result of the flow meter 1.

[0035] In the technical solution of the present invention, it is possible to realize the feedforward linkage adjustment of the dosing amount of the chemical agent and the water inflow of the sewage, realize the accurate metering and accurate dosing of the chemical agent, thereby avoiding the situation of insufficient dosing amount or excessive dosing amount of the chemical agent caused by the change of the water inflow. By controlling the flow rate of the metering pump 2 by the control device 4, it is possible to avoid increasing the labor intensity of the operator caused by manually adjusting the flow rate of the metering pump 2, thereby realizing the automatic and accurate metering and accurate dosing of the chemical agent, reducing the consumption of the chemical agent while ensuring the stable compliance of the sewage treatment system, and reducing the operation cost of the system.

[0036] In one embodiment, the flow meter 1 includes an electromagnetic flow meter, which has high accuracy and stable and reliable operation, and can improve the accuracy of the detection result of the water inflow of the sewage, thereby further improving the accuracy of the dosing amount of the chemical agent.

[0037] In one embodiment, the metering pump 2 includes a digital metering pump, which has stable performance and can display the real-time data and cumulative data of its flow rate on its body panel, making it more convenient and intuitive to view and adjust its flow rate, thus facilitating the accurate dosing and regulation of the chemical agent, and at the same time facilitating the management and cost accounting of the chemical agent. The above two embodiments can exist alternatively or simultaneously.

[0038] In this embodiment, the oilfield sewage treatment system 100 further includes a water quality detection device 5 provided corresponding to the water outlet. The control device 4 is electrically connected to the water quality detection device 5 and is configured to control the flow rate of at least one of the metering pumps 2 according to the detection result of the water quality detection device 5. In this way, the feedback linkage adjustment of the dosing amount of the chemical agent and the water quality of the system effluent is realized, further realizing the accurate metering and accurate dosing of the chemical agent, and ensuring the compliance of the effluent water quality.

[0039] The above embodiments can exist simultaneously. Specifically, the flow rate of the electromagnetic flowmeter and the dosing amounts of various chemicals are matched for the dosing amount of the digital metering pump and the water inflow of the system through PID operation. The detection data of the effluent water quality and the PID operation of the dosing amount are used for another fine adjustment of the chemical dosage, thereby ensuring the accurate metering and accurate dosing of various chemicals in the sewage treatment system, and further making the dosing of chemicals the most economical and reasonable under the condition of ensuring the long-term stable and up-to-standard treatment of the sewage treatment system.

[0040] In this embodiment, the multiple dosing ports are used to dose demulsifier, bactericide, corrosion inhibitor, and water purifying agent. The water quality detection device 5 includes an SS detector, a PH detector, and a conductivity monitor; the metering pump 2 includes multiple first metering pumps respectively arranged corresponding to the multiple dosing ports for dosing demulsifier, bactericide, and corrosion inhibitor, and a second metering pump arranged corresponding to the dosing port for dosing water purifying agent; the control device 4 is used to respectively control the flow rates of the multiple first metering pumps according to the detection results of the flowmeter 1, and is used to control the flow rate of the second metering pump according to the detection results of the SS detector. In this way, the dosing amounts of demulsifier, bactericide, and corrosion inhibitor are feedback-adjusted according to the detection data of the flowmeter 1 at the water inlet, and the dosing amount of water purifying agent is feedback-adjusted according to the detection data of the SS detector, so as to achieve the accurate metering and accurate dosing of demulsifier, bactericide, corrosion inhibitor, and water purifying agent. The detection data of the PH detector and the conductivity monitor are used to detect the effluent water quality. Specifically, the SS detector, the PH detector, and the conductivity monitor are installed in a flow-through tank type, and the treated sewage is reinjected. The SS detector, the PH detector, and the conductivity monitor are located at the inlet of the reinjection pump.

[0041] In this embodiment, the multiple sewage treatment devices 3 include a three-phase separator 31, a settler 32, and a filter 33; on the purification flow path, the multiple dosing ports include a first dosing port located between the water inlet of the pipeline and the three-phase separator 31, multiple second dosing ports located between the three-phase separator 31 and the settler 32, and a third dosing port located between the filter 33 and the water outlet of the pipeline. The first dosing port is used to dose a demulsifier, the multiple second dosing ports are respectively used to dose a bactericide, an inhibitor, and a water purifying agent, and the third dosing port is used to dose a bactericide. Thus, on the purification flow path, the oilfield sewage first passes through the three-phase separator 31 to separate oil and mud (solids), and the remaining water is mixed with the bactericide, inhibitor, and water purifying agent. The bactericide sterilizes, the inhibitor protects the system, and the water purifying agent is mainly a flocculant. Then, solid-liquid separation is carried out in the settler 32, and suspended solids and particulate matters in the water body are removed in the filter 33 to reduce turbidity. After dosing the bactericide again for sterilization, the treated water is discharged or reinjected, achieving full purification of the oilfield sewage and ensuring the purification effect. Specifically, on the purification flow path, before the settler 32, a pipeline mixer is further provided in the pipeline. The pipeline mixer mixes the wastewater, bactericide, inhibitor, and water purifying agent evenly, which can improve the action effects of the bactericide, inhibitor, and water purifying agent.

[0042] In this embodiment, the control device 4 includes a control module and a display module communicatively connected to the control module. The control module is respectively communicatively connected to the flowmeter 1 and multiple metering pumps 2, and is configured to control the flow rate of at least one of the metering pumps 2 according to the detection result of the flowmeter 1. The control module is further configured to obtain the flow rates of the multiple metering pumps 2. The display module is configured to be communicatively connected to a display device, and is configured to display the flow rates of the multiple metering pumps 2 obtained by the control module on the display device. In this way, curves and reports related to the dosing amounts of chemicals can be saved and output, and the real-time dosing amounts and cumulative dosing amounts of various chemicals in the sewage treatment system can be accurately fed back. The automated drawing of flow curves and output of reports can, while accurately counting the dosing amounts of various chemicals, reflect changes in the influent water quality and quantity of the system, making it more convenient for the management and operation of the sewage treatment system. Specifically, the control device 4 includes a PLC control system. The communication mode between the PLC control system and various devices is the Rs485 communication mode. The control module includes a microprocessor CPU and a memory component. The display module includes an input and output component. The display device includes a PC-side display unit and a mobile-side display unit. The PC-side display unit is connected to the control device 4 through a network cable, and receives in real time the operation data of the oilfield sewage treatment system 100 sent by the PLC control module, and performs real-time dynamic display in the form of BIM. The mobile-side display unit is connected to the control device 4 through a 5G network, and receives in real time the operation data of the oilfield sewage treatment system 100 sent by the PLC control module, and performs real-time dynamic display in the form of BIM.

[0043] In this embodiment, the oilfield sewage treatment system 100 further includes multiple chemical preparation devices 6 corresponding to the multiple dosing ports. Each chemical preparation device 6 includes a preparation tank 61, a stirrer 62, and a liquid level gauge 63. The preparation tank 61 is provided with a water inlet 611, a chemical inlet 612, and a chemical outlet 613. The chemical outlet 613 is communicated with the corresponding dosing port. Electric valves are provided at both the water inlet 611 and the chemical inlet 612. The stirrer 62 includes a stirring part extending into the preparation tank 61. The liquid level gauge 63 is configured to detect the liquid level in the preparation tank 61. In this way, various chemicals can be prepared in a timely manner, ensuring the timely supply of chemicals to the oilfield sewage treatment system 100 and ensuring its stable operation.

[0044] In one embodiment, the control device 4 is electrically connected to the electric valve, the mixer 62, and the liquid level gauge 63 respectively to automate the chemical agent configuration and improve the system operation efficiency. Specifically, when the configured concentration of the chemical agent is determined to be 10%, and the liquid level gauge 63 shows that 0 point is the low liquid level protection liquid level, when the control device 4 obtains that the liquid level in the configuration tank 61 detected by the liquid level gauge 63 reaches 0 point, the digital metering pump 2 is controlled to enter the low liquid level protection state and stop and cannot be started, and the electric valve at the water filling port is opened to enter the water replenishment program. When the replenished liquid level reaches the set liquid level of 1170 mm corresponding to the configured concentration (at this time, the volume of water is 1.8 m3), the electric valve at the water filling port is closed, the electric valve at the chemical agent adding port is opened, and the mixer 62 is started. When the liquid level reaches the set liquid level of 1300 mm corresponding to the configured concentration (the volume of the chemical agent is 0.2 m3), the electric valve at the chemical agent adding port is closed, the timer is started to count, and when the set delay time of 15 min (which can be set and modified according to the actual situation) is reached, the mixer 62 is closed, and it enters the normal chemical agent dosing mode.

[0045] In one embodiment, the material of the configuration tank 61 includes one of polypropylene homopolymer (PPH), polypropylene (PP), and polyethylene (PE). Polypropylene homopolymer (PPH), polypropylene (PP), and polyethylene (PE) have high anti-corrosion functions, which can avoid the corrosion and leakage of the configuration tank 61, improve its service life and use stability, ensure the long-term stable operation of the chemical agent dispensing device 6, and thus ensure the long-term stable operation of the oilfield sewage treatment system 100. In one embodiment, the electric valve includes an explosion-proof electric butterfly valve, which is safer and more reliable. In one embodiment, the mixer 62 includes an explosion-proof paddle mixer, which is safer and more reliable. In one embodiment, the liquid level gauge 63 includes an explosion-proof and anti-corrosion magnetic flap liquid level gauge, which is safer and more reliable. The above four embodiments can exist alternatively or multiple of them can exist simultaneously. Specifically, the chemical agent dispensing device 6 further includes a configuration damper, a back pressure valve, a safety valve, a pressure gauge, etc. to achieve the stability of the device for chemical agent configuration.

[0046] The present invention also provides an oilfield sewage treatment method based on the oilfield sewage treatment system 100 as described above. The oilfield sewage treatment method includes the following steps:

[0047] S11: Obtain the detection result of the flowmeter 1;

[0048] S21: Control the flow rate of at least one of the metering pumps 2 according to the detection result of the flowmeter 1.

[0049] In this embodiment, by obtaining the detection result of the flowmeter 1, the sewage flow rate at the water inlet is obtained, and the flow rate of the metering pump 2 is controlled, so as to regulate the dosing amount of the chemical agent, realize the automatic and accurate metering and accurate dosing of the chemical agent, reduce the consumption of the chemical agent while ensuring the stable compliance of the sewage treatment system, and reduce the operation cost of the system.

[0050] Further, the oilfield sewage treatment system 100 further includes a water quality detection device 5 provided corresponding to the water outlet. The control device 4 is electrically connected to the water quality detection device 5 and is configured to control the flow rate of at least one of the metering pumps 2 according to the detection result of the water quality detection device 5. The oilfield sewage treatment method further includes the following steps:

[0051] S12: Obtain the detection result of the water quality detection device 5;

[0052] S22: Control the flow rate of at least one of the metering pumps 2 according to the detection result of the water quality detection device 5.

[0053] In this embodiment, by obtaining the detection result of the water quality detection device 5, the water quality of the water outlet is obtained, the flow rate of the metering pump 2 is controlled, so as to regulate the dosage of the chemical agent, realizing the feedback linkage adjustment of the dosage of the chemical agent and the water quality of the system effluent, further realizing the accurate metering and accurate dosing of the chemical agent, and ensuring that the effluent water quality meets the standards.

[0054] The above are only the preferred embodiments of the present invention, and do not limit the patent scope of the present invention. Any equivalent structural transformation made under the concept of the present invention by using the content of the specification and drawings of the present invention, or directly / indirectly applied to other related technical fields, is included in the patent protection scope of the present invention.

Claims

1. An oilfield sewage treatment system, characterized in that, The described oilfield sewage treatment system includes: A pipeline, the pipeline having a water inlet and a water outlet 、 and a purification flow path located between the water inlet and the water outlet, a plurality of dosing ports are provided on the side wall of the pipeline, a flow meter is provided at the water inlet of the pipeline, and a plurality of metering pumps are provided corresponding to the plurality of dosing ports one by one; A plurality of sewage treatment devices, which are arranged in series on the purification flow path; and, A control device, which is electrically connected to the flowmeter and the plurality of metering pumps respectively, and is used to control the flow rate of at least one of the metering pumps according to the detection result of the flowmeter.

2. The oilfield sewage treatment system according to claim 1, characterized in that, The flowmeter includes an electromagnetic flowmeter; and / or, the metering pump includes a digital metering pump.

3. The oilfield sewage treatment system according to claim 1, characterized in that, The oilfield sewage treatment system further includes a water quality detection device corresponding to the water outlet, and the control device is electrically connected to the water quality detection device and is used to control the flow rate of at least one of the metering pumps according to the detection result of the water quality detection device.

4. The oilfield sewage treatment system according to claim 3, characterized in that, The plurality of dosing ports are used to dose demulsifiers, bactericides, corrosion inhibitors, and water purifying agents, and the water quality detection device includes an SS detector, a PH detector, and a conductivity monitor; The metering pumps include a plurality of first metering pumps corresponding to the plurality of dosing ports for dosing demulsifiers, bactericides, and corrosion inhibitors, and a second metering pump corresponding to the dosing port for dosing water purifying agents; The control device is used to control the flow rates of the plurality of first metering pumps respectively according to the detection result of the flowmeter, and is used to control the flow rate of the second metering pump according to the detection result of the SS detector.

5. The oilfield sewage treatment system according to any one of claims 1 to 4, characterized in that, The plurality of sewage treatment devices include a three-phase separator, a settler, and a filter; On the purification flow path, the plurality of dosing ports include a first dosing port between the water inlet of the pipeline and the three-phase separator, a plurality of second dosing ports between the three-phase separator and the settler, and a third dosing port between the filter and the water outlet of the pipeline. The first dosing port is used to dose demulsifiers, and the plurality of second dosing ports are respectively used to dose bactericides, corrosion inhibitors, and water purifying agents, and the third dosing port is used to dose bactericides.

6. The oilfield sewage treatment system according to claim 1, characterized in that The control device includes: A control module, which is communicatively connected to the flowmeter and the plurality of metering pumps respectively, and is used to control the flow rate of at least one of the metering pumps according to the detection result of the flowmeter. The control module is also used to obtain the flow rates of the plurality of metering pumps; and, A display module, which is communicatively connected to the control module. The display module is used to be communicatively connected to a display device and is used to display the flow rates of the plurality of metering pumps obtained by the control module on the display device.

7. The oilfield sewage treatment system according to claim 1, wherein The oilfield sewage treatment system further includes a plurality of medicine preparation devices corresponding to the plurality of dosing ports. Each medicine preparation device includes: A preparation tank, which is provided with a water inlet, a medicine inlet, and a medicine outlet. The medicine outlet is communicated with the corresponding dosing port, and electric valves are arranged at both the water inlet and the medicine inlet; A stirrer, which includes a stirring part extending into the preparation tank; and, A liquid level gauge, which is used to detect the liquid level in the preparation tank.

8. The oilfield sewage treatment system according to claim 6, wherein The material of the preparation tank includes one of homopolypropylene (PPH), polypropylene (PP), and polyethylene (PE); and / or, The electric valve includes an explosion-proof electric butterfly valve; and / or, The mixer includes an explosion-proof paddle mixer; and / or, The liquid level gauge includes an explosion-proof and corrosion-proof magnetic flap liquid level gauge.

9. A method for treating oilfield sewage, characterized in that, Based on the oilfield sewage treatment system described in claim 1, the oilfield sewage treatment method includes the following steps: Obtain the detection result of the flowmeter; According to the detection result of the flowmeter, control the flow rate of at least one of the metering pumps.

10. The oilfield sewage treatment method according to claim 9, wherein, The oilfield sewage treatment system further includes a water quality detection device provided corresponding to the water outlet. The control device is electrically connected to the water quality detection device and is used to control the flow rate of at least one of the metering pumps according to the detection result of the water quality detection device. The oilfield sewage treatment method further includes the following steps: Obtain the detection result of the water quality detection device; According to the detection result of the water quality detection device, control the flow rate of at least one of the metering pumps.

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