Skid-mounted bromine extraction device for recycling scattered point source bromine resources of oil and gas field produced water

Abstract

The invention provides a skid-mounted bromine extraction device for recycling scattered point source bromine resources of oil and gas field produced water, which relates to the field of resource recovery and treatment and is characterized in that a chemical in-situ preparation and addition unit, a bromine ion in-situ oxidation unit and a bromine elementary substance separation and enrichment unit which are communicated with one another are integrated in a container shell; the skid-mounted integrated platform and the intelligent control and energy source unit are used for integrating all the units, the small skid-mounted device is used for concentrating the low-concentration bromine-containing produced water into stable and safe enriched liquid on a well site, and the transportation cost of dispersed materials is reduced. Complicated processes are integrated in a standard container to form a skid-mounted module, the skid-mounted module can be quickly transported to a site and can be operated only by receiving water, connecting electricity and regularly supplying sodium chloride, and the project flexibility and deployment speed are greatly improved. By adopting bipolar membrane electrodialysis to prepare an acid-base raw material solution, replacing chlorine oxidation with electrochemical oxidation, replacing a stripping tower with gaseous membrane separation and combining solar power supply, the whole process is more compact and lower in energy consumption, and accords with the green and low-carbon development direction.

Description

Technical Field

[0001] This invention relates to the field of resource recovery and treatment technology, and more specifically, to a skid-mounted bromine extraction device for recovering bromine resources from dispersed point sources in produced water from oil and gas fields. Background Technology

[0002] As my country's oil and gas resource development continues to expand into deeper and unconventional areas, the amount of produced water from oil and gas fields is increasing year by year. Currently, conventional treatment involves a three-stage process of oil separation, air flotation, and filtration to meet standards before reinjection into the formation. This type of produced water typically has high salinity and high salt content; in some blocks, the bromide ion concentration in the produced water can reach tens to hundreds of milligrams per liter, possessing certain resource recovery value. Bromine and its compounds are widely used in flame retardants, drilling fluids, pharmaceuticals, pesticides, and photosensitive materials, and are important strategic non-metallic elements. Therefore, recovering bromine resources from produced water from oil and gas fields aligns with the national strategic direction of promoting resource recycling and green, low-carbon development.

[0003] Currently, the main bromine extraction technologies for bromine-containing water bodies, both domestically and internationally, include air blowing, solvent extraction, ion exchange, and membrane separation. Among these, the air blowing-absorption method is widely used in industry due to its mature technology, strong adaptability, and suitability for low-concentration bromine recovery. However, when applied to produced water from dispersed point sources in oil and gas fields, existing technologies have revealed several shortcomings and defects, as follows: Heavy reliance on chemicals: Traditional processes require the continuous addition of chemicals such as sulfuric acid, chlorine, and sodium hydroxide. Sulfuric acid and chlorine are hazardous chemicals, and decentralized well sites lack standardized conditions for chemical storage, transportation, and addition, resulting in high safety risks and costs.

[0004] The equipment is large and fixed: Traditional blowing towers, absorption towers and other equipment have a single tower processing capacity of about 1200 cubic meters / hour. Each unit is installed independently and cannot be moved due to its reliance on civil engineering structure. It occupies a large area and cannot be adapted to the current situation of scattered well sites and limited space.

[0005] High energy consumption and poor adaptability: For low-concentration, small-volume produced water, large traditional equipment has low operating energy efficiency, poor economic performance, low degree of automation, and relies on manual operation.

[0006] Therefore, there is an urgent need in this field for a skid-mounted bromine extraction device that is highly integrated and can be rapidly deployed, free from dependence on external chemicals, in order to achieve on-site, efficient, and economical recovery of dispersed point-source bromine resources in oil and gas fields. Summary of the Invention

[0007] The purpose of this invention is to address the problems raised in the existing background technology. To achieve the above-mentioned objective, this invention provides the following technical solution: a skid-mounted bromine extraction device for recovering bromine resources from dispersed point sources in produced water of oil and gas fields, integrated within a container shell, comprising a chemical in-situ preparation and dosing unit, a bromide ion in-situ oxidation unit, a bromine element separation and enrichment unit connected in sequence, as well as a skid-mounted integrated platform and an intelligent control and energy unit integrating the aforementioned units; The chemical in-situ preparation and dosing unit is used to electrolyze an externally added sodium chloride solution to simultaneously generate hydrochloric acid and sodium hydroxide. The hydrochloric acid is used to adjust the pH value of the produced water, and the sodium hydroxide is used as an absorbent. The in-situ bromide ion oxidation unit is connected to the produced water feed pipeline and receives the hydrochloric acid. It uses an electrochemical oxidation method to convert bromide ions in the produced water into elemental bromide. The bromine element separation and enrichment unit includes a gaseous membrane module. The inlet of the gaseous membrane module on the raw material side is connected to the outlet of the bromide ion in-situ oxidation unit, and the absorption side is circulated with the sodium hydroxide absorbent, which is used to separate bromine and form an enriched solution. The intelligent control and energy unit includes a PLC controller, a control display, a sensor network, and a solar power generation system. The solar power generation system is located on the top of the container and is used to power the device and realize fully automated control.

[0008] As a preferred technical solution of the present invention, the in-situ chemical preparation and dosing unit is a bipolar membrane electrodialysis device, which generates hydrochloric acid in the cathode chamber and sodium hydroxide in the anode chamber by electrolyzing a saturated sodium chloride solution.

[0009] As a preferred technical solution of the present invention, the bromide ion in-situ oxidation unit is an electrochemical reactor. The extracted water is mixed with hydrochloric acid to adjust the pH to 2.8-3.2 and then enters the reactor to complete the bromide ion oxidation under the action of an electric field.

[0010] As a preferred technical solution of the present invention, the gaseous membrane module is filled with hollow fiber hydrophobic membrane filaments, and elemental bromine permeates through the micropores of the membrane wall in gaseous form and is absorbed by the sodium hydroxide absorbent on the absorption side to generate sodium bromide and sodium bromate.

[0011] As a preferred embodiment of the present invention, the bromide ion concentration of the enrichment solution is 60-80 g / L, and the enrichment solution is stored in an enrichment solution storage tank integrated in a container.

[0012] As a preferred technical solution of the present invention, the container is a 20-foot standard container, which is internally divided into a control area, a reaction area and a storage area. The control area is equipped with a control cabinet for an intelligent control and energy unit, the reaction area is equipped with a chemical in-situ preparation and dosing unit, a bromide ion in-situ oxidation unit and a bromine elemental separation and enrichment unit, and the storage area is equipped with an enrichment liquid storage tank.

[0013] As a preferred technical solution of the present invention, the solar power generation system includes an deployable solar support rod and a solar power generation panel, with a daily power supply of 5-10 kWh.

[0014] As a preferred technical solution of the present invention, the sensor network includes a pH sensor, a conductivity sensor and a flow sensor, which are respectively arranged at the inlet and outlet of each unit to provide real-time feedback of process parameters to the PLC controller.

[0015] As a preferred technical solution of the present invention, it also includes a mother liquor neutralization module, which is connected to the raw material side outlet of the bromine elemental separation and enrichment unit and is used to neutralize the mother liquor after bromine extraction. After reaching the standard, the mother liquor is reinjected into the formation. The chemical in-situ preparation and dosing unit is equipped with a metering pump, which is electrically connected to a PLC controller to realize the precise dosing of hydrochloric acid and sodium hydroxide.

[0016] A method for bromine extraction using a skid-mounted bromine extraction device for recovering bromine resources from dispersed point sources in produced water of oil and gas fields, characterized by comprising the following steps: S1. On-site preparation of chemicals: Start the electrolysis unit to electrolyze sodium chloride solution and produce hydrochloric acid and sodium hydroxide for later use; S2. Feeding and Pretreatment: Introduce produced water from the oil and gas field into the system and add hydrochloric acid prepared in step S1 to adjust the pH to 2.8-3.2; S3. In-situ oxidation: The pretreated produced water is pumped into the electrochemical oxidation unit, where bromide ions are oxidized to elemental bromide under the action of an electric field; S4. Membrane separation and preliminary enrichment: The water containing bromine is introduced into the gaseous membrane module. The bromine permeates through the membrane wall in gaseous form and is absorbed by the sodium hydroxide absorbent on the other side to generate sodium bromide and sodium bromate. Through continuous circulation of the absorbent, the concentration of bromide ions is increased to 60-80 g / L, and a stable sodium bromide enriched solution is obtained and stored in the enriched solution storage tank. S5. Mother liquor treatment and reinjection: The mother liquor after bromine extraction is neutralized and reinjected into the formation after meeting the standards; S6. Centralized Refining: The high-concentration sodium bromide enriched solutions produced at each dispersion point are centrally transported to the regional center and refined using steam distillation to finally obtain industrial bromine products.

[0017] Compared with the prior art, the beneficial effects of the present invention are as follows: The present invention pioneers a new model of "dispersed enrichment and centralized refining": by using a small skid-mounted device on the well site, low-concentration bromine-containing produced water is concentrated into a stable and safe enriched liquid, which greatly reduces the transportation cost and risk of dispersed materials and solves the core contradiction of raw material dispersion.

[0018] This invention achieves closed-loop process and self-sufficiency in raw materials: all the required acids, bases and chlorine are prepared on-site by electrochemical methods, completely eliminating dependence on external supply chains of hazardous chemicals and making it possible to recover bromine resources in remote well sites.

[0019] This invention features high integration and rapid deployment: complex processes are integrated into a standard container to form a skid-mounted module that can be quickly transported to the site. It only requires water and electricity connection and a regular supply of sodium chloride to operate, greatly improving the flexibility and deployment speed of the project.

[0020] This invention is green, safe, and efficient: it uses electrochemical oxidation instead of chlorine oxidation, gaseous membrane separation instead of a blow-out tower, and solar power, making the whole process safer, more compact, more environmentally friendly, and with lower energy consumption, in line with the direction of green and low-carbon development. Attached Figure Description

[0021] Figure 1 This is a schematic diagram of the structure provided by the present invention; Figure 2 This is a schematic diagram of the gaseous membrane module structure provided by the present invention.

[0022] The image shows: 1. Container shell; 2. In-situ chemical preparation and dosing unit; 3. In-situ bromide ion oxidation unit; 4. Bromine element separation and enrichment unit; 401. Gas membrane module; 5. Intelligent control and energy unit; 501. PLC controller; 502. Control display; 6. Solar power generation system. Detailed Implementation

[0023] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of the present invention.

[0024] Therefore, the following detailed description of the embodiments of the present invention is not intended to limit the scope of the claimed invention, but merely illustrates some embodiments of the invention. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without inventive effort are within the scope of protection of the present invention. It should be noted that, in the absence of conflict, the embodiments and features and technical solutions in the embodiments of the present invention can be combined with each other. It should be noted that similar reference numerals and letters in the following figures indicate similar items; therefore, once an item is defined in one figure, it does not need to be further defined and explained in subsequent figures.

[0025] Example 1: The skid-mounted bromine extraction system of this example is installed entirely within a 20-foot standard container shell 1. The interior of the container is divided into a control area, a reaction area, and a storage area from left to right.

[0026] The in-situ chemical preparation and dosing unit 2 is located in the reaction zone, and its core is a bipolar membrane electrodialysis device. This device electrolyzes a saturated sodium chloride solution from an external feed tank to produce hydrochloric acid in the cathode chamber and sodium hydroxide in the anode chamber, which are then precisely added to subsequent processes via metering pumps.

[0027] The bromide ion in-situ oxidation unit 3 employs an electrochemical reactor. The treated water enters through a feed pipe and a pump, is mixed with added hydrochloric acid to adjust the pH to approximately 3, and then enters the reactor. Under a specific current density, bromide ions are oxidized to elemental bromine at the anode surface.

[0028] The bromine elemental separation and enrichment unit 4 is the core of the system. The oxidized water enters the gaseous membrane module 401. This module is filled with hollow fiber hydrophobic membrane filaments. Due to its volatility, bromine, in gaseous form, permeates through the micropores of the membrane wall and enters the other side of the membrane filaments. On this side, a sodium hydroxide absorbent, driven by a circulating pump, continuously circulates, absorbing the gaseous bromine and reacting it to generate sodium bromide and sodium bromate. Through continuous circulation of the absorbent, the bromide ion concentration is increased to 60-80 g / L, resulting in a stable sodium bromide enriched solution, which is stored in an enriched solution storage tank. This enriched solution is chemically stable and can be transported as a non-hazardous chemical.

[0029] The treated bromine extraction mother liquor undergoes neutralization and, after meeting standards, is reinjected underground through a discharge pipe. The control cabinet of the intelligent control and energy unit 5 is equipped with a PLC, electrically connected to each pump, valve, and sensor to achieve fully automatic control. The control display 502 is used for parameter setting and status monitoring. An extendable solar support pole and solar panels are installed on the top of the container, providing the system with 5-10 kWh of electricity per day, significantly reducing dependence on the external power grid.

[0030] The workflow of this invention is as follows: After the device arrives at the well site, the solar panels are deployed, and the water and power sources are connected. The system is then started on the control panel. The device first prepares a saturated sodium chloride solution and initiates bipolar membrane electrodialysis to prepare sufficient acid and alkali. Subsequently, produced water is introduced, and the process sequentially completes steps such as pH adjustment, electrochemical oxidation, gaseous membrane separation and enrichment, and deep desorption and concentration, ultimately producing a high-concentration sodium bromide enriched solution stored in a tank. Operators periodically replace the enriched solution storage tank and replenish the saturated sodium chloride solution. The enriched solution is then transferred to a regional center for unified distillation and purification to obtain the final bromine product. The entire process is highly automated, requiring no manual addition of chemicals on-site.

[0031] In summary, through systematic process integration and innovation, this invention successfully provides an economical, efficient, green, and feasible solution for the recovery of bromine resources from dispersed point sources in oil and gas fields.

[0032] This device, with its core structure of decentralized enrichment and centralized purification, integrates functional units such as chemical preparation, bromide ion oxidation, membrane separation, and intelligent control within a 20-foot standard container, enabling on-site concentration and safe transfer of low-concentration bromine resources. Its working principle revolves around a closed-loop process of energy self-sufficiency, raw material self-sufficiency, reaction conversion, separation and enrichment, and intelligent control, fundamentally solving the pain points of traditional bromine extraction technologies, such as reliance on hazardous chemicals, large equipment size, and poor adaptability.

[0033] Intelligent Control and Energy Unit 5: Green Power Supply and Full-Process Regulation Foundation: The deployable solar power generation system 6 on the top of the container, including solar support rods and power generation panels, converts solar energy into electrical energy through photoelectric conversion, with an average daily power supply of 5-10 kWh, prioritizing power supply to each unit; when sunlight is insufficient, the system automatically switches to the external power grid for supplementary energy, achieving a balance between green power supply and stable operation.

[0034] As the core control hub, the PLC controller 501 uses a sensor network, including pH sensors, conductivity sensors, and flow sensors, to collect process parameters at the inlet and outlet of each unit in real time, such as the produced water flow rate, pH value, and enrichment concentration. It also automatically adjusts key operations such as pump and valve start-up and shutdown, electrolysis intensity, and reagent dosage according to preset programs. The control display 502 simultaneously realizes parameter visualization and manual intervention functions, requiring no manual operation throughout the process.

[0035] In-situ Chemical Preparation and Dosing Unit 2: The Core of Breaking Free from Dependence on Hazardous Chemicals This unit uses a bipolar membrane electrodialysis device to achieve self-sufficiency in acid and alkali by electrolyzing an externally added saturated sodium chloride solution. The principle is as follows: under the action of an electric field, the bipolar membrane undergoes water dissociation, producing H⁺ and OH⁻; at the same time, Na⁺ in the sodium chloride solution migrates to the cathode, and Cl⁻ migrates to the anode.

[0036] In the cathode chamber, H⁺ enters through the bipolar membrane and combines with Cl⁻ to form hydrochloric acid, which is then stored in an acidic tank. In the anode chamber, OH⁻ enters through the bipolar membrane and combines with Na⁺ to form sodium hydroxide, NaOH, which is then stored in an alkaline tank.

[0037] Hydrochloric acid and sodium hydroxide are precisely added to the subsequent pH adjustment and absorption processes via PLC-controlled metering pumps, enabling on-site preparation and on-demand addition of chemicals, completely avoiding the transportation and storage risks of hazardous chemicals such as sulfuric acid and chlorine in traditional processes.

[0038] In-situ bromide ion oxidation unit 3: Efficient conversion of bromide ions to elemental bromide: Pretreatment and pH adjustment: After the oil and gas field produced water is introduced through the feed pipeline, it is mixed with hydrochloric acid produced by the chemical preparation unit. The pH value is monitored and adjusted to 2.8-3.2 in real time by a pH sensor. This acidic environment can significantly improve the efficiency of the subsequent bromide ion oxidation reaction.

[0039] Electrochemical oxidation mechanism: After pH adjustment, the treated water enters the electrochemical reactor. Under the action of an electric field with a specific current density, bromide ions, Br⁻, undergo an oxidation reaction on the anode surface: 2Br⁻-2e⁻→Br₂, directly converting into volatile elemental bromine, Br₂. Compared with the traditional chlorine oxidation method, this process does not require the addition of an oxidant, avoiding the risk of chlorine leakage and residual chlorine pollution.

[0040] Bromine Separation and Enrichment Unit 4: Key Steps in Membrane Concentration: This unit uses gaseous membrane module 401 as its core, utilizing the volatility of bromine and the selective permeability of the hydrophobic membrane to achieve separation and enrichment. The specific mechanism is as follows: Membrane separation basis: The hollow fiber hydrophobic membrane filaments filled inside the gaseous membrane module 401, such as modified polytetrafluoroethylene membrane, have excellent hydrophobicity and oxidation resistance. The gas filling the micropores of the membrane wall forms a gaseous medium layer, which separates the bromine-containing produced water on the feed side from the sodium hydroxide solution on the absorber side, thus preventing direct mixing between the two phases and providing a channel for the mass transfer of bromine.

[0041] Mass transfer and enrichment process: Feed side: Bromine-containing produced water flows through the membrane fiber tube. Due to its volatility, the bromine vaporizes and enters the gaseous medium layer through the micropores of the membrane wall in a gaseous form. Absorption side: The sodium hydroxide absorbent flows counterclockwise along the membrane fiber shell under the drive of the circulating pump, and reacts with gaseous bromine: 3Br2 + 6NaOH → 5NaBr + NaBrO3 + 3H2O, generating stable sodium bromide and sodium bromate. Concentration mechanism: Through continuous circulation of the absorbent, bromide ions accumulate on the absorption side until the concentration reaches a set value, forming a chemically stable enriched solution. This enriched solution is stored in a container's storage tank and can be safely transported as a non-hazardous chemical. Mother liquor treatment and subsequent refining: closed loop of environmental protection emission and resource recycling: Mother liquor treatment principle: After the bromine extraction mother liquor is separated by gas membrane, the concentration of bromide ions is greatly reduced. It enters the mother liquor neutralization module, and the pH value is adjusted to neutral by adding sodium hydroxide produced by the chemical preparation unit. After meeting the standard, it is directly reinjected into the formation to avoid wastewater discharge pollution.

[0042] Centralized refining and integration: The enriched liquids from each decentralized well site are uniformly transported to the regional center, where they are heated by steam distillation. The difference in boiling points between bromine and other components is used to achieve separation, ultimately yielding industrial bromine products, thus completing the resource recovery closed loop of decentralized enrichment and centralized refining.

[0043] Full-process collaborative working logic: Start-up phase: After the device arrives at the well site, the solar panels are deployed and the water and power sources are connected. The PLC controller 501 starts the bipolar membrane electrodialysis device to prepare sufficient hydrochloric acid and sodium hydroxide reserves. Operation phase: After the produced water is introduced, pH adjustment, hydrochloric acid addition, electrochemical oxidation are carried out in sequence to generate elemental bromine, gaseous membrane separation and enrichment to form a high-concentration enriched solution, and mother liquor neutralization and reinjection. The core control mechanism involves real-time parameter feedback from sensors, dynamic adjustment of electrolysis current by the PLC, control of acid and alkali production, metering pump dosage, stabilization of pH value and circulation pump speed, and optimization of membrane mass transfer efficiency; ensuring that each link operates in a coordinated manner. Final stage: After the enrichment solution storage tank is full, the operator replaces the storage tank and transfers it. The system continues to monitor and maintains a standby state.

[0044] The above embodiments are only used to illustrate the present invention and are not intended to limit the technical solutions described herein. Although the present invention has been described in detail with reference to the above embodiments, the present invention is not limited to the specific embodiments described above. Therefore, any modifications or equivalent substitutions to the present invention, as well as all technical solutions and improvements that do not depart from the spirit and scope of the invention, are covered within the scope of the claims of the present invention.

Claims

1. A skid-mounted bromine extraction device for recovering bromine resources from dispersed point sources of oil and gas field produced water, characterized in that, Integrated in the container shell (1), comprising in turn chemical in-situ preparation and dosing unit (2), bromide ion in-situ oxidation unit (3), bromine element separation and enrichment unit (4), and pry integrated platform integrated with the units and intelligent control and energy unit (5); The chemical in-situ preparation and dosing unit (2) is used for electrolyzing an added sodium chloride solution, simultaneously generating hydrochloric acid and sodium hydroxide, the hydrochloric acid is used for adjusting the pH value of produced water, and the sodium hydroxide is used as an absorption liquid; The bromide ion in-situ oxidation unit (3) is connected with a produced water feeding pipeline at the inlet and receives the hydrochloric acid, and an electrochemical oxidation method is used to convert bromide ions in the produced water into bromine element; The bromine element separation and enrichment unit (4) comprises a gaseous membrane assembly (401), the gaseous membrane assembly (401) is connected with the outlet of the bromide ion in-situ oxidation unit (3) at the raw material side, and the absorption side is circularly connected with the sodium hydroxide absorption liquid, used for separating bromine element and forming an enrichment liquid; The intelligent control and energy unit (5) comprises a PLC controller (501), a control display (502), a sensor network and a solar power generation system (6), the solar power generation system (6) is arranged on the top of the container, used for supplying power for the device and realizing automatic control of the whole process.

2. The skid-mounted bromine extraction device for oil and gas field produced water dispersed point source bromine resource recovery according to claim 1, characterized in that, The chemical in-situ preparation and dosing unit (2) is a bipolar membrane electrodialysis device, saturated sodium chloride solution is electrolyzed to generate hydrochloric acid in the cathode chamber and sodium hydroxide in the anode chamber.

3. The prying dress bromine extraction device for oil and gas field produced water dispersed point source bromine resource recovery according to claim 1, characterized in that, The bromide ion in-situ oxidation unit (3) is an electrochemical reactor, after the produced water is mixed with the hydrochloric acid to adjust the pH value to 2.8-3.2, the mixture enters the reactor, and the oxidation of bromide ions is completed under the action of an electric field.

4. The prying dress bromine extraction device for oil and gas field produced water dispersed point source bromine resource recovery according to claim 1, characterized in that, The gaseous membrane assembly (401) is filled with hollow fiber hydrophobic membrane filaments inside, bromine element is in a gaseous form and penetrates through the micropores of the membrane wall, and is absorbed by the sodium hydroxide absorption liquid at the absorption side to generate sodium bromide and sodium bromate.

5. The prying dress bromine extraction device for oil and gas field produced water dispersed point source bromine resource recovery according to claim 1, characterized in that, The bromide ion concentration of the enrichment liquid is 60-80 g / L, and the enrichment liquid is stored in an enrichment liquid storage tank integrated in the container.

6. The skid-mounted bromine extraction device for oil and gas field produced water dispersed point source bromine resource recovery according to claim 1, characterized in that, The container is a 20-foot standard container, which is divided into a control area, a reaction area and a storage area, the control cabinet of the intelligent control and energy unit (5) is arranged in the control area, the chemical in-situ preparation and dosing unit (2), the bromide ion in-situ oxidation unit (3) and the bromine element separation and enrichment unit (4) are arranged in the reaction area, and the enrichment liquid storage tank is arranged in the storage area.

7. The prizing device for recovering bromine resource from dispersed point sources of oilfield produced water according to claim 1, characterized in that, The solar power generation system (6) comprises an expandable solar support rod and a solar power generation panel, and the daily average power supply is 5-10 kWh.

8. The skid-mounted bromine extraction device for oil and gas field produced water dispersed point source bromine resource recovery according to claim 1, characterized in that, The sensor network comprises pH sensors, conductivity sensors and flow sensors, which are arranged at the inlets and outlets of the units respectively, and real-time feedback of process parameters to the PLC controller (501).

9. The prizing device for recovering bromine resource from dispersed point sources of oilfield produced water according to claim 1, characterized in that, It also comprises a mother liquor neutralization module connected with the raw material side outlet of the bromine element separation and enrichment unit (4), used for neutralizing the mother liquor after bromine extraction, and backfilling the stratum after reaching the standard, the chemical in-situ preparation and dosing unit (2) is provided with a metering pump, the metering pump is electrically connected with the PLC controller (501), and accurate dosing of the hydrochloric acid and the sodium hydroxide is realized.

10. A method for recovering bromine from a dispersed point source of bromine resources in oil and gas field produced water using the skid-mounted bromine extraction device of any one of claims 1-9, characterized in that, The method comprises the following steps: S1. On-site preparation of chemicals: start the electrolysis device, electrolyze sodium chloride solution to produce hydrochloric acid and sodium hydroxide reserve for later use; S2. Feed and pretreatment: introduce oil and gas field produced water into the system and add hydrochloric acid prepared in step S1 to adjust the pH to 2.8-3.2; S3. In-situ oxidation: pump the pretreated produced water into the electrochemical oxidation unit, and oxidize bromide ions to bromine under the action of electric field; S4. Membrane separation and preliminary enrichment: make the water containing bromine monomer enter the gaseous membrane assembly (401), and the bromine monomer in gaseous form penetrates the membrane wall and is absorbed by the sodium hydroxide absorption liquid on the other side to generate sodium bromide and sodium bromate. Through the continuous circulation of the absorption liquid, the bromide ion concentration is increased to 60-80 g / L, and a stable sodium bromide enrichment liquid is obtained and stored in the enrichment liquid storage tank; S5. Mother liquor treatment and reinjection: treat the bromine-extracted mother liquor for neutralization, and reinject it into the formation after reaching the standard; S6. Centralized refining: concentrate the high-concentration sodium bromide enrichment liquid produced by each dispersed point and transport it to the regional center, and use the water vapor distillation method for refining to finally obtain industrial bromine product.

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