Treatment and reinjection system for offshore heavy oil high-temperature produced water

Abstract

The invention belongs to the technical field of water treatment, and particularly relates to an offshore thick oil high-temperature produced water treatment and reinjection system. In order to solve the problem that the impurity removal effect cannot meet the existing reinjection water requirement in the prior art, the invention provides an offshore thick oil high-temperature produced water treatment reinjection system which comprises an oil removal system and a fine filtration system which are communicated with each other, and one end, far away from the oil removal system, of the fine filtration system is further communicated with a membrane filtration system. The membrane filtration system comprises a membrane filtration raw water tank, a security filter, a high-temperature ultrafiltration device and a water injection buffer tank which are communicated in sequence, the membrane filtration raw water tank is communicated with the fine filtration system, and the water injection buffer tank is communicated with a water injection well. The membrane filtration system is arranged, produced water is finely filtered and then sequentially enters the membrane filtration raw water tank, the security filter and the high-temperature ultrafiltration device to be subjected to membrane filtration, the water treatment effect is remarkably improved, the reinjection or discharge requirement is met, and the filtered produced water can be directly injected into a water injection well.

Description

Technical Field

[0001] The invention belongs to the technical field of water treatment, and in particular relates to an offshore heavy oil high-temperature produced water treatment and reinjection system. Background Art

[0002] The high-temperature produced water from offshore heavy oil usually dissolves and carries a large amount of petroleum substances, inorganic salts, bacteria and solid particles, etc. The water quality is complex and difficult to treat. Usually, the oil content in produced water is 100-5000 mg / L, of which about 90% is suspended oil and dispersed oil, about 10% is emulsified oil and a small amount of dissolved oil. The suspended matter is composed of a variety of solid particles, such as clay, paraffin, bacterial flocs, silt and insoluble organic matter. Most of the current mainstream processes use the treatment process of air flotation-sand filtration-walnut shell filtration, but with the improvement of produced water standards, this process can no longer meet the filtration needs. At the same time, the sludge and sludge generated during the traditional process are hazardous wastes and need to be transported out. The storage cost and transportation cost are too high, and the existing equipment has a low degree of integration and high land requirements. Therefore, it is urgent to provide a new treatment system that can be applied to the treatment of high-temperature produced water from offshore heavy oil.

[0003] However, its effect in removing impurities is limited, and most of the produced water after treatment cannot meet the reinjection standards, and the impurity removal effect needs to be improved.

[0004] For example, a Chinese invention patent discloses a method for treating oilfield produced water [application number: 201910328713.3]. The invention application includes: it uses a gravity sedimentation device, an electric field oil removal device and a filtering device, and includes the following steps: gravity sedimentation, transporting the produced water to the gravity sedimentation device for preliminary separation of oil, water and mud; electric field oil removal, transporting the sewage after gravity sedimentation to the electric field oil removal device to remove emulsified oil and suspended matter; and filtration, transporting the effluent after electric field oil removal to the filtering device to further remove emulsified oil and suspended matter, so that the effluent meets the reinjection requirements.

[0005] This invention has the advantage of being able to achieve rapid, efficient and low-cost treatment of oilfield produced water, and in particular, being able to improve the removal efficiency of emulsified oil, but it still does not solve the above-mentioned problems. Summary of the invention

[0006] The object of the present invention is to provide an offshore heavy oil high temperature produced water treatment and reinjection system in view of the above problems.

[0007] In order to achieve the above object, the present invention adopts the following technical solutions:

[0008] An offshore heavy oil high-temperature produced water treatment and reinjection system comprises an oil removal system and a fine filtration system which are interconnected, the oil removal system is also connected to a waste oil treatment system for treating waste oil separated by the oil removal system, the fine filtration system is also connected to a sludge treatment system for treating solid impurities separated by the fine filtration system, the fine filtration system is also connected to a membrane filtration system at one end away from the oil removal system, the membrane filtration system comprises a membrane filtration raw water tank, a safety filter, a high-temperature ultrafiltration device and a water injection buffer tank which are connected in sequence, the membrane filtration raw water tank is connected to the fine filtration system, and the water injection buffer tank is connected to a water injection well.

[0009] In the above-mentioned offshore heavy oil high-temperature produced water treatment and reinjection system, the oil removal system includes a cyclone separator connected to the high-temperature produced water source, one end of the flotation device is connected to the cyclone separator, and the other end is connected to the fine filtration system;

[0010] The waste oil treatment system comprises a waste oil storage tank, a thermal cracking device and an oil-water separation device which are connected in sequence. The flotation device is connected to the waste oil storage tank and the waste oil separated in the flotation device is stored in the waste oil storage tank. The oil-water separation device is connected to the flotation device and the water phase separated in the oil-water separation device flows back into the flotation device.

[0011] In the above-mentioned offshore heavy oil high-temperature produced water treatment and reinjection system, the fine filtration system includes a fine filtration raw water tank, a self-cleaning filter, a multi-media filter and a walnut shell filter which are connected in sequence, the fine filtration raw water tank is connected to the oil removal system, and the walnut shell filter is connected to the membrane filtration raw water tank.

[0012] In the above-mentioned offshore heavy oil high-temperature produced water treatment and reinjection system, the membrane filtration system also includes an ultrafiltration chemical cleaning device and an ultrafiltration backwashing device, both of which are connected to the high-temperature ultrafiltration device. The ultrafiltration backwashing device is connected to the self-cleaning filter, the multi-media filter and the walnut shell filter respectively, and the ultrafiltration backwashing device can transport backwash water to the self-cleaning filter, the multi-media filter and the walnut shell filter respectively.

[0013] In the above-mentioned offshore heavy oil high-temperature produced water treatment and reinjection system, the sludge treatment system includes a backwash wastewater collection tank, a sedimentation tank, a sludge concentration tank, a sludge filter press system and a sludge drying equipment which are connected in sequence, the self-cleaning filter, the multi-media filter and the walnut shell filter are all connected to the backwash wastewater collection tank, the sedimentation tank is connected to the fine filtration raw water tank, and the water phase separated after sedimentation in the sedimentation tank is transported to the fine filtration raw water tank.

[0014] In the above-mentioned offshore heavy oil high-temperature produced water treatment and reinjection system, it also includes a seawater desalination system, which includes a sand filter device, a reverse osmosis device, a water production tank and a dosing system that are connected in sequence. The reverse osmosis device is connected to the sludge drying equipment, and the concentrated water output by the reverse osmosis device is used to accelerate the removal of steam generated in the sludge drying equipment.

[0015] In the above-mentioned offshore heavy oil high-temperature produced water treatment and reinjection system, the high-temperature ultrafiltration device includes an outer shell body with a filter cavity inside, a mounting piece is fixedly arranged in the outer shell body, a water outlet cavity is provided above the mounting piece, one end of the filter membrane thread is fixedly connected to the mounting piece, and the other end is a free end, the filter cavity is connected with the water outlet cavity through the filter membrane thread, the upper end of the outer shell body is also provided with a water production port and an upper discharge port, the water production port is connected with the water outlet cavity, the upper discharge port is connected with the filter cavity, the lower end of the outer shell body is also provided with a water inlet and a lower discharge port, the water inlet and the lower discharge port are both connected with the filter cavity, an aeration structure is also provided in the filter cavity, the aeration structure is slidably connected to the outer shell body, and one end of the aeration structure extends to the outside of the outer shell body and is connected with an external air source.

[0016] In the above-mentioned offshore heavy oil high-temperature produced water treatment and reinjection system, the aeration structure includes a cylindrical aeration body, a gas delivery hose is provided on the aeration body, one end of the gas delivery hose away from the aeration body is connected to an air inlet provided on the outer shell, and the air inlet is connected to an external air source. A plurality of gas delivery channels are opened in the aeration body, one end of the gas delivery channel is connected to the gas delivery hose, and the other end passes through the top surface and the side surface of the aeration body to form an axial gas outlet and a radial gas outlet.

[0017] In the above-mentioned offshore heavy oil high-temperature produced water treatment and reinjection system, the bottom of the aeration body is also connected to a lifting structure, and the side of the aeration body is provided with a guide groove recessed toward the inside of the aeration body, and the guide groove is slidably connected to a guide block protruding from the inner surface of the outer shell;

[0018] The aeration structure also includes a convergence disk fixedly connected to the inner surface of the aeration body. The convergence disks are provided in plurality and are arranged in sequence along the axis of the aeration body. A clearance hole penetrating the convergence disk is provided at the center of the convergence disk. The convergence disk is also provided with a plurality of membrane wire limiting holes evenly distributed circumferentially along the axis of the convergence disk. The sliding aeration body can allow the free end of the filter membrane wire to pass through the membrane wire limiting hole.

[0019] In the above-mentioned offshore heavy oil high-temperature produced water treatment and reinjection system, the filter membrane filament is made of hydrophilic PVDF material, and the hydrophilic PVDF material is prepared by the following method:

[0020] Step 1: placing the PVDF powder under an electron accelerator for pre-irradiation, adjusting the parameters of the irradiation equipment so that the irradiation dose is 20-200 kGy, and the irradiation dose rate is 50-15000 Gy / s, preferably, the irradiation dose is 30-120 kGy, and the irradiation dose rate is 2000-10000 Gy / s; obtaining the pretreated PVDF material;

[0021] Step 2: dissolving the pretreated PVDF material obtained in step 1 in a strong polar organic solvent, N-methyl-2-pyrrolidone can be selected as the strong polar organic solvent, stirring under nitrogen protection until completely dissolved, and then adding a vinyl hydrophilic monomer and an initiator, wherein the vinyl hydrophilic monomer is one or more of acrylamide, acrylic acid and hydroxyethyl acrylate, and the amount of the hydrophilic monomer is 0.1%-10% of the amount of the pretreated PVDF material, and the initiator is an organic peroxide initiator and / or an azo initiator, for example, azobisisobutyronitrile, and the amount of the initiator is 0.1%-5% of the mass of the solution system, heating to 50-80°C, stirring the reaction for 3-6h, and filtering the reaction solution to obtain a hydrophilic PVDF material.

[0022] Hydrophilic PVDF material can be made into filter membrane by the following methods:

[0023] The hydrophilic PVDF material, porogen and additive are dissolved in a solvent. The porogen can be polyethylene glycol, and the amount added is 0.5%-3% of the hydrophilic PVDF material. The additive can include polysiloxane, and the amount added is 0.1-0.5% of the hydrophilic PVDF material. After stirring and dissolving at 50-70°C, the casting solution is allowed to stand for degassing to obtain the casting solution. The casting solution is extruded from the spinneret, and then passed through an external coagulation bath and washed in sequence to obtain the hydrophilic PVDF material hollow filtration membrane.

[0024] Compared with the prior art, the advantages of the present invention are:

[0025] 1. The present invention realizes resource utilization for produced water from offshore platforms. In terms of water resources, water is reused as reinjection water; in terms of oil components, thermal cracking products are sold as fuel oil; in terms of energy, high-temperature produced water is reused as high-temperature reinjection water, thereby reducing energy consumption.

[0026] 2. There is a membrane filtration system. After fine filtration, the produced water passes through the membrane filtration raw water tank, safety filter and high-temperature ultrafiltration device in sequence to achieve membrane filtration, which significantly improves the water treatment effect and meets the requirements of reinjection or discharge. The filtered produced water can be directly injected into the injection well.

[0027] 3. The present invention uses part of the produced water as backwash water for the high-temperature ultrafiltration device, realizing internal backwash water supply without external input. The backwash water of the high-temperature ultrafiltration device is used as backwash water for the fine filtration system, further ensuring the reuse of the backwash water inside the system, which can greatly save water. At the same time, the setting of the sludge treatment system realizes the efficient treatment of the backwash water and improves the environmental protection performance of the system.

[0028] 4. The present invention provides an aeration structure that can move up and down in the high-temperature ultrafiltration device to improve the aeration efficiency. The aeration structure is also provided with a radial outlet that can discharge air in a direction perpendicular to the axis of the filter membrane wire, so that more surface contact can occur between the filter membrane wires during the aeration process, which promotes the removal of impurities attached to the surface of the filter membrane wire due to filtration. At the same time, a plurality of membrane wire limiting holes arranged along the axis direction are used to relatively limit the position of the filter membrane wire, which can avoid the problem of entanglement and knotting between the filter membrane wires during the aeration process to a certain extent.

[0029] 5. The present invention uses modified hydrophilic PVDF material to make filter membrane filaments, so that the filter membrane filaments can withstand higher temperatures while ensuring hydrophilicity, so that the membrane filtration system can directly perform filtering operations at higher temperatures without cooling the produced water to be filtered, thereby simplifying the operating steps and equipment structure. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] Figure 1 It is a structural schematic diagram of the present invention;

[0031] Figure 2 It is a structural schematic diagram of a high temperature ultrafiltration device;

[0032] Figure 3 for Figure 2 The enlarged view of point A in the middle;

[0033] Figure 4 is a schematic diagram of the aeration structure;

[0034] In the figure: oil removal system 1, fine filtration system 2, membrane filtration system 3, waste oil treatment system 4, sludge treatment system 5, seawater desalination system 6, aeration structure 7, cyclone separator 11, flotation device 12, fine filtration raw water tank 21, self-cleaning filter 22, multi-media filter 23, walnut shell filter 24, membrane filtration raw water tank 31, security filter 32, high temperature ultrafiltration device 33, water injection buffer tank 34, water injection well 35, ultrafiltration chemical cleaning device 36, ultrafiltration backwash device 37, waste oil storage tank 41, thermal cracking device 42, oil-water separation device 43, backwash wastewater collection box 51, sedimentation tank 5 2. Sludge thickening tank 53, sludge filter press system 54, sludge drying equipment 55, sand filter device 61, reverse osmosis device 62, water production tank 63, dosing system 64, aeration body 71, gas hose 72, air inlet 73, gas channel 74, axial air outlet 75, radial air outlet 76, lifting structure 77, guide groove 78, guide block 79, convergence disk 7a, membrane wire limiting hole 7b, give way hole 7c, filter cavity 331, outer shell 332, mounting part 333, water outlet cavity 334, filter membrane filament 335, water production port 336, upper outlet 337, lower outlet 338, water inlet 339. DETAILED DESCRIPTION

[0035] The present invention will be further described in detail below with reference to the accompanying drawings and specific implementation methods.

[0036] Example 1

[0037] This embodiment provides a system for processing and reinjecting high-temperature produced water from offshore heavy oil. Figure 1 As shown, it includes an oil removal system 1 and a fine filtration system 2 which are interconnected. The oil removal system 1 is also connected to a waste oil treatment system 4 for treating the waste oil separated by the oil removal system 1, and the fine filtration system 2 is also connected to a sludge treatment system 5 for treating solid impurities separated by the fine filtration system 2. The fine filtration system 2 is also connected to a membrane filtration system 3 at one end away from the oil removal system 1.

[0038] The oil removal system 1 removes oil from high-temperature produced water to reduce the oil content. The fine filtration system 2 further filters fine impurities in the produced water to improve the water quality. The membrane filtration system 3 performs high-efficiency filtration to further purify the water quality and provide high-quality water for water injection. The sludge treatment system 5 is used to treat the sludge generated in each link to avoid polluting the environment.

[0039] Specifically, the oil removal system 1 includes a cyclone separator 11 connected to a high-temperature produced water source, and one end of the air flotation device 12 is connected to the cyclone separator 11 , and the other end is connected to the fine filtration system 2 .

[0040] The pollutants in the high-temperature produced water mainly include suspended solids and oil accumulated during the recycling and injection process of the reinjected water. The suspended solid content in the inlet water is ≥100mg / L, the oil is ≥100mg / L, the pH value is 5-9, and the temperature is 60-100℃. The high-temperature produced water passes through the cyclone separator 11 and the flotation device 12 in sequence. The cyclone separator 11 uses centrifugal force to preliminarily separate the oil in the high-temperature produced water. The flotation device 12 further removes the oil and some solid impurities in the produced water to obtain a preliminary filtrate, and the oil content of the filtrate is ≤20mg / L.

[0041] Specifically, the fine filtration system 2 includes a fine filtration raw water tank 21, a self-cleaning filter 22, a multi-media filter 23 and a walnut shell filter 24 which are connected in sequence. The fine filtration raw water tank 21 is connected to the oil removal system 1, and the walnut shell filter 24 is connected to the membrane filtration raw water tank 31.

[0042] The preliminary filtrate is transported from the flotation device 12 to the fine filtration system 2, which performs fine filtration on the produced water after oil removal to remove fine impurities to obtain a fine filtration filtrate, in which the oil content is ≤5mg / L and the suspended matter is ≤5mg / L.

[0043] The liquid inlet of the self-cleaning filter 22 is connected to the liquid outlet of the fine filtration raw water tank 21, automatically filtering the larger particles of impurities in the inlet liquid, and can clean the filter screen by itself, ensuring the continuity and stability of the filtration and reducing the manual maintenance cost;

[0044] The liquid inlet of the multi-media filter 23 is connected to the liquid outlet of the self-cleaning filter 22. The filtration speed of the multi-media filter 23 is between 6-20m / h. It uses different media to further remove impurities such as suspended particles and organic matter in the inlet liquid, thereby further improving the water quality.

[0045] The liquid inlet end of the walnut shell filter 24 is connected to the liquid outlet end of the multi-media filter 23. The walnut shell is used as the filtering medium, and the filtering speed is between 15-20m / h. It deeply filters the oil, tiny particles, etc. in the water, especially the treatment effect of oil-containing produced water is better, and the oil content and impurity content in the produced water can be effectively reduced. After triple fine filtration, a fine filtered liquid is obtained; the liquid outlet end of the walnut shell filter 24 is connected to the liquid inlet end of the membrane filtration raw water tank 31, and the fine filtered liquid is further transported to the membrane filtration system 3 for subsequent treatment.

[0046] The backwash water inlet end of the self-cleaning filter 22, the backwash water inlet end of the multi-media filter 23, and the backwash water inlet end of the walnut shell filter 24 are respectively connected to the backwash water output end of the high-temperature ultrafiltration device 33; since the self-cleaning filter 22, the multi-media filter 23, and the walnut shell filter 24 will inevitably have residual pollution after the inlet liquid is filtered, the backwash water of the high-temperature ultrafiltration device 33 can be respectively transported to the self-cleaning filter 22, the multi-media filter 23, and the walnut shell filter 24 as backwash water for cleaning, which can greatly save the external water required for cleaning.

[0047] Specifically, the membrane filtration system 3 includes a membrane filtration raw water tank 31, a security filter 32, a high temperature ultrafiltration device 33 and a water injection buffer tank 34 which are connected in sequence. The membrane filtration raw water tank 31 is connected to the fine filtration system 2, and the water injection buffer tank 34 is connected to a water injection well 35.

[0048] The liquid inlet of the membrane filtration system 3 is connected to the liquid outlet of the fine filtration system 2, and the water outlet of the high-temperature ultrafiltration device 33 is connected to the water injection well 35. The fine filtration filtrate is transported from the walnut shell filter 24 to the membrane filtration raw water tank 31, and is filtered again by the high-temperature ultrafiltration device 33 to obtain the final produced water, with the suspended solids of the produced water ≤1mg / L and the oil content ≤3mg / L, ensuring that the water quality of the high-temperature produced water reaches high standards after treatment and meets the requirements for reinjection or discharge.

[0049] Specifically, the waste oil treatment system 4 includes a waste oil storage tank 41, a thermal cracking device 42 and an oil-water separation device 43 which are connected in sequence. The flotation device 12 is connected to the waste oil storage tank 41 and the waste oil separated in the flotation device 12 is stored in the waste oil storage tank 41. The oil-water separation device 43 is connected to the flotation device 12 and the water phase separated in the oil-water separation device 43 flows back to the flotation device 12.

[0050] The floating oil input end of the waste oil storage tank 41 is connected to the floating oil output end of the air flotation device 12, and is used to receive the floating oil separated by the air flotation device 12 when treating the produced water. Through this connection method, the floating oil dispersed in the produced water can be collected and collected to provide raw materials for subsequent treatment processes. This design allows the subsequent treatment process to be carried out according to a certain rhythm and process, rather than processing the continuously generated floating oil in real time, which facilitates the unified management and regulation of the waste oil treatment process.

[0051] The thermal cracking device 42 performs low-temperature distillation on the floating oil collected in the waste oil storage tank 41, and separates the components by using the difference in boiling points of different substances. The water and low-boiling impurities are evaporated first, and the oil is retained for purification to improve the oil quality and facilitate subsequent recycling. This distillation process can separate recyclable components, such as pure oil, to provide pure raw materials for subsequent oil-water separation, etc., to achieve preliminary recovery of some waste oil resources and reduce waste.

[0052] The oil-water separation device 43 receives the mixed liquid after being treated by the thermal cracking device and realizes fine oil-water separation, such as using physical or chemical methods such as gravity, centrifugation, and coagulation to finely separate the residual oil and water, ensuring that the oil is pure and the water meets the standards, which is convenient for subsequent treatment and recycling.

[0053] The water outlet of the oil-water separator 43 is connected to the liquid inlet of the flotation device 12, and the water resources are recycled at the same time. The water containing a small amount of oil and some impurities is sent back to the flotation device 12 for re-floatation treatment, so as to realize the recycling of water resources, improve the utilization efficiency and reduce the dependence on external fresh water. The flotation device 12 is used to provide a source of waste oil and recycle the treated water resources. When the produced water is treated, the flotation device 12 uses its own oil removal mechanism, such as injecting tiny bubbles to make the oil droplets adhere and float to separate, separate the floating oil and output it to the waste oil storage tank 41, to feed the waste oil treatment, and at the same time receive the water treated by the oil-water separator 43, so that the water treated by the oil-water separator 43 returns to the liquid inlet of the flotation device 12, and participates in the oil removal treatment of the produced water again, so as to realize the recycling of water resources, reduce the demand for fresh water, and maintain the water balance of the device and the stability of the treatment effect.

[0054] like Figure 1 As shown, the membrane filtration system 3 also includes an ultrafiltration chemical cleaning device 36 and an ultrafiltration backwashing device 37, both of which are connected to the high-temperature ultrafiltration device 33. The ultrafiltration backwashing device 37 is connected to the self-cleaning filter 22, the multi-media filter 23 and the walnut shell filter 24 respectively, and the ultrafiltration backwashing device 37 can transport backwash water to the self-cleaning filter 22, the multi-media filter 23 and the walnut shell filter 24 respectively.

[0055] The ultrafiltration chemical cleaning device 36 is connected to the high-temperature ultrafiltration device 33. The produced water is mainly reused as oilfield reinjection water, and part of it is used as backwash water for the high-temperature ultrafiltration device 33. The backwash water accounts for about 5%-10% of the total produced water. The ultrafiltration chemical cleaning device 36 backwashes the high-temperature ultrafiltration device 33 with the produced water remaining in the high-temperature ultrafiltration device 33, which can remove membrane contamination and restore its filtration performance. Part of the produced water is used as backwash water for the high-temperature ultrafiltration device 33 to realize internal backwash water supply without input from the outside, which can greatly save water. The ultrafiltration chemical cleaning device 36 can also chemically clean the high-temperature ultrafiltration device 33 in the membrane filtration system 3, and use a deep cleaning agent to remove membrane contamination and restore filtration performance.

[0056] The backwash water output end of the high temperature ultrafiltration device 33 is connected to the backwash water inlet end of the fine filtration system 2. An ultrafiltration backwash device 37 is arranged between the high temperature ultrafiltration device 33 and the fine filtration system 2, and its liquid inlet end is connected to the backwash water output end of the high temperature ultrafiltration device 33, and its liquid outlet end is connected to the backwash water inlet end of the fine filtration system 2. The main function of the ultrafiltration backwash device 37 is to collect the backwash water discharged by the high temperature ultrafiltration device 33 during the backwash operation, to realize the temporary storage of the backwash water, and to avoid the backwash water from being discharged arbitrarily to cause environmental pollution or waste of water resources.

[0057] like Figure 1 As shown, the sludge treatment system 5 includes a backwash wastewater collection tank 51, a sedimentation tank 52, a sludge concentration tank 53, a sludge filter press system 54 and a sludge drying equipment 55 which are connected in sequence. The self-cleaning filter 22, the multi-media filter 23 and the walnut shell filter 24 are all connected to the backwash wastewater collection tank 51, the sedimentation tank 52 is connected to the fine filtration raw water tank 21, and the water phase separated after sedimentation in the sedimentation tank 52 is transported to the fine filtration raw water tank 21.

[0058] The liquid inlet end of the backwash wastewater collection box 51 is connected to the backwash water output end of the self-cleaning filter 22, the backwash water output end of the multi-media filter 23, and the backwash water output end of the walnut shell filter 24, respectively, and is used to collect the backwash wastewater generated by the backwashing of the fine filtration system 2.

[0059] The sedimentation tank 52 receives the total backwash water delivered by the backwash wastewater collection box 51. It can be any one of the horizontal flow sedimentation tanks, high-density tanks, and micro-sand sedimentation tanks, or any combination of them. The suspended sludge particles in the wastewater are naturally settled to the bottom of the tank by gravity, thereby achieving the initial separation of sludge and water. After treatment in the sedimentation tank, the concentration of the settled sludge can be between 95% and 99%.

[0060] The sludge after sedimentation in the sedimentation tank 52 enters the sludge thickening tank 53. The sludge thickening tank 53 further concentrates the sludge sent from the sedimentation tank 52, and further discharges the water in the sludge through natural sedimentation or other auxiliary means, such as adding flocculants, etc., to increase the solid content of the sludge and reduce the volume of the sludge, so as to facilitate subsequent sludge treatment operations, such as filter pressing and drying.

[0061] The sludge compressed by the sludge thickening tank 53 enters the sludge filter pressing system 54, and the sludge filter pressing system 54 can use a filter press or a screw press. The sludge filter pressing system 54 performs a filter pressing operation on the concentrated sludge sent from the sludge thickening tank 53, and by applying a certain pressure, forces the water in the sludge to be discharged through filter media such as filter cloth, thereby achieving a more thorough separation of sludge and water. The screw press utilizes the principle of screw extrusion, and through the changes in the screw diameter and pitch and the strong extrusion force generated by the small gap between the floating ring and the fixed ring, the sludge is squeezed and dehydrated to obtain a filter cake-shaped sludge with a low water content, thereby improving the dehydration effect of the sludge and facilitating the subsequent sludge disposal or utilization.

[0062] The sludge treated by the sludge filter press system 54 enters the sludge drying equipment 55. The sludge drying equipment 55 can use a vacuum rake dryer. The produced water can be directly discharged into the sea, and the obtained oil sludge is sent out for treatment. The sludge drying equipment 55 dries the filter cake sludge sent by the sludge filter press system 54. Through heating, ventilation and other drying methods, the residual water in the sludge is further removed, and the water content of the sludge is reduced to a lower level, so that it becomes a dry solid substance, which is convenient for storage, transportation or final disposal, such as landfill, incineration, etc., and also reduces the volume and weight of the sludge, reducing the subsequent treatment cost.

[0063] The liquid outlet end of the sludge concentration tank 53 and the liquid outlet end of the sludge filter press system 54 are respectively connected to the liquid inlet end of the sedimentation tank 52, and the liquid outlet end of the sedimentation tank 52 is connected to the liquid inlet end of the fine filtration raw water tank 21. In this way, the liquid treated by the sludge concentration tank and the sludge filter press device returns to the sedimentation tank again, and the produced water obtained after sedimentation in the sedimentation tank can be returned to the fine filtration raw water tank for storage and reserved for later use.

[0064] like Figure 1 As shown, it also includes a seawater desalination system 6, which includes a sand filter device 61, a reverse osmosis device 62, a water production tank 63 and a dosing system 64 that are connected in sequence. The reverse osmosis device 62 is connected to the sludge drying equipment 55, and the concentrated water output by the reverse osmosis device 62 is accelerated to carry out the steam generated in the sludge drying equipment 55 through the Venturi effect and the vacuum pump.

[0065] The main function of the sand filter device 61 is to perform preliminary filtration on the seawater entering the seawater desalination system. The sand filter medium intercepts larger particle impurities in the seawater, such as silt, suspended matter, etc., to reduce the turbidity of the seawater, provide relatively clean water for the subsequent operation of the reverse osmosis device 62, prevent large particle impurities from clogging the reverse osmosis membrane, and extend the service life of the reverse osmosis device 62.

[0066] The reverse osmosis device 62 is the core equipment of the seawater desalination system. It uses the principle of a semipermeable membrane to allow water molecules in the seawater to pass through the semipermeable membrane under pressure, while impurities such as salt are retained, thereby achieving the desalination of seawater to obtain fresh water and concentrated water. The fresh water is transported to the water production tank 63 for storage and can be further used as a high-quality water resource, while the concentrated water contains a higher concentration of salt and other impurities.

[0067] The liquid inlet end of the dosing system 64 is connected to the liquid outlet end of the water production tank 63. The water production tank 63 is used to store the fresh water obtained by the reverse osmosis device 62, and plays a role of buffering and temporary storage. Ensure that there is a stable supply of fresh water to the subsequent dosing system 64, etc., to meet the demand for fresh water in the subsequent treatment or use process, and ensure the continuity and stability of the entire produced water treatment system. After the dosing system 64 receives the desalinated water sent by the water production tank 63, it further adjusts and treats the desalinated water by adding specific agents, such as disinfectants, pH regulators, etc., so that it meets specific usage requirements or complies with relevant water quality standards, so that it can be used safely and effectively in subsequent application scenarios, such as industrial water, domestic water, etc.

[0068] Combination Figure 2-4 As shown, the high temperature ultrafiltration device 33 includes an outer shell 332 with a filter cavity 331 inside, a mounting member 333 is fixedly arranged in the outer shell 332, a water outlet cavity 334 is provided above the mounting member 333, one end of the filter membrane filament 335 is fixedly connected to the mounting member 333, and the other end is a free end, the filter cavity 331 is connected to the water outlet cavity 334 through the filter membrane filament 335, and a water outlet 336 and an upper outlet 337 are also provided at the upper end of the outer shell 332. The water outlet 336 is connected to the water outlet cavity 334, the upper outlet 337 is connected to the filter cavity 331, and the lower end of the outer shell 332 is also provided with a water inlet 339 and a lower outlet 338, both of which are connected to the filter cavity 331. An aeration structure 7 is also provided in the filter cavity 331, and the aeration structure 7 is slidably connected to the outer shell 332. One end of the aeration structure 7 extends to the outside of the outer shell 332 and is connected to an external air source.

[0069] The raw water to be filtered enters the filter cavity 331 through the water inlet 339, and after being filtered by the filter membrane filament 335, the produced water enters the water outlet cavity 334 through the hollow cavity inside the filter membrane filament 335, and is discharged through the water outlet 336. The concentrated water remaining in the water outlet cavity 334 after filtration can be discharged through the lower discharge port 338.

[0070] The water temperature required for filtration at the high-temperature ultrafiltration device 33 is about 80°C, but most of the materials used to prepare the filter membrane filaments 335 in the prior art cannot withstand such high temperatures, so the water to be filtered must be cooled down by a heat exchange device first. This requires additional heat exchange devices and heat exchange steps, which leads to complex operating steps and equipment structures. Moreover, heat loss cannot be avoided during the heat exchange process. PVDF material is a high-temperature resistant material, but its own nature is hydrophobic (in the technical field involved in the present invention, hydrophilic materials refer to materials that are water-permeable but not air-permeable, and hydrophobic materials refer to materials that are impermeable but air-permeable), and cannot be used in the preparation of filter membrane filaments 335.

[0071] Therefore, the present invention obtains a modified hydrophilic PVDF material suitable for preparing the filter membrane filament 335 by modifying the PVDF material. The specific steps are as follows:

[0072] Step 1: Place the PVDF powder under an electron accelerator for pre-irradiation, adjust the irradiation equipment parameters so that the irradiation dose is 200 kGy and the irradiation dose rate is 50 Gy / s, and obtain the pre-treated PVDF material;

[0073] Step 2: Dissolve the pretreated PVDF material obtained in step 1 in N-methyl-2-pyrrolidone, stir under nitrogen protection until completely dissolved, then add acrylic acid monomer and azobisisobutyronitrile, the amount of acrylic acid monomer added is 0.1% of the pretreated PVDF material, and the amount of azobisisobutyronitrile added is 5% of the mass of the solution system, heat to 80°C, stir and react for 6 hours, and filter the reaction solution to obtain a hydrophilic PVDF material.

[0074] Combination Figure 2-4 As shown, the aeration structure 7 includes a cylindrical aeration body 71, on which a gas hose 72 is provided, and one end of the gas hose 72 away from the aeration body 71 is connected to an air inlet 73 provided on the outer shell 332, and the air inlet 73 is connected to an external air source. A plurality of gas delivery channels 74 are opened in the aeration body 71, and one end of the gas delivery channel 74 is connected to the gas hose 72, and the other end passes through the top surface and the side surface of the aeration body 71 to form an axial air outlet 75 and a radial air outlet 76.

[0075] Although the ultrafiltration chemical cleaning device 36 can chemically clean the filter membrane filaments 335 to remove membrane pollution. However, long-term and frequent chemical cleaning will damage the filter membrane filaments 335 and shorten their service life. Therefore, an aeration structure 7 is provided to perform air washing on the surface of the filter membrane filaments 335 while performing aeration, so as to clean the surface of the filter membrane filaments 335 and restore the filtering performance. The aeration structure 7 is also provided with a radial air outlet 76 that can discharge air in a direction perpendicular to the axis of the filter membrane filaments 335, so that more surface contacts can occur between the filter membrane filaments 335 during the aeration process, thereby promoting the shedding of impurities attached to the surface of the filter membrane filaments 335 due to filtration, and improving the air washing effect.

[0076] like Figure 3 As shown, the bottom of the aeration body 71 is also connected to a lifting structure 77, and the side of the aeration body 71 is provided with a guide groove 78 recessed into the aeration body 71, and the guide groove 78 is slidably connected to a guide block 79 protruding from the inner surface of the outer shell 332. The lifting structure 77 can drive the aeration body 71 to move along the axis direction, thereby improving the aeration efficiency.

[0077] like Figure 4 As shown, the aeration structure 7 also includes a convergence disk 7a fixedly connected to the inner surface of the aeration body 71. The convergence disk 7a is provided with a plurality of convergence disks 7a and arranged in sequence along the axial direction of the aeration body 71. A clearance hole 7c penetrating the convergence disk 7a is provided at the center position of the convergence disk 7a. The convergence disk 7a is also provided with a plurality of membrane thread limiting holes 7b uniformly distributed along the circumferential direction of the axial direction of the convergence disk 7a. The membrane thread limiting holes 7b are tiny holes and are uniformly distributed on the surface of the convergence disk 7a. The sliding aeration body 71 can allow the free end of the filter membrane thread 335 to pass through the membrane thread limiting hole 7b. After the aeration body 71 moves in the direction close to the filter membrane thread 335, several filter membrane threads 335 with similar distances pass through the membrane thread limiting holes 7b in a bundle. Therefore, the present invention uses multiple membrane thread limiting holes 7b arranged along the axial direction to relatively limit the position of the filter membrane thread 335, which can avoid the problem of entanglement and knotting between the filter membrane threads 335 during the aeration process to a certain extent.

[0078] Example 2

[0079] This embodiment provides an offshore heavy oil high temperature produced water treatment and reinjection system, combined with Figure 1-4 As shown, its specific structure is substantially the same as the specific structure described in Example 1, and the only difference is the preparation method of the hydrophilic PVDF material for preparing the filter membrane filament 335. The specific preparation method is as follows:

[0080] Step 1: Pre-irradiate the PVDF powder under an electron accelerator, adjust the irradiation equipment parameters so that the irradiation dose is 20 kGy and the irradiation dose rate is 15000 Gy / s, and obtain the pre-treated PVDF material;

[0081] Step 2: Dissolve the pretreated PVDF material obtained in step 1 in N-methyl-2-pyrrolidone, stir under nitrogen protection until completely dissolved, then add acrylic acid monomer and azobisisobutyronitrile, the amount of acrylic acid monomer added is 10% of the pretreated PVDF material, and the amount of azobisisobutyronitrile added is 0.1% of the mass of the solution system, heat to 50°C, stir and react for 3 hours, and filter the reaction solution to obtain a hydrophilic PVDF material.

[0082] Example 3

[0083] This embodiment provides an offshore heavy oil high temperature produced water treatment and reinjection system, combined with Figure 1-4 As shown, its specific structure is substantially the same as the specific structure described in Example 1, and the only difference is the preparation method of the hydrophilic PVDF material for preparing the filter membrane filament 335. The specific preparation method is as follows:

[0084] Step 1: Pre-irradiate the PVDF powder under an electron accelerator, adjust the irradiation equipment parameters so that the irradiation dose is 75 kGy and the irradiation dose rate is 6000 Gy / s, and obtain the pre-treated PVDF material;

[0085] Step 2: Dissolve the pretreated PVDF material obtained in step 1 in N-methyl-2-pyrrolidone, stir under nitrogen protection until completely dissolved, then add acrylic acid monomer and azobisisobutyronitrile, the amount of acrylic acid monomer added is 5% of the pretreated PVDF material, and the amount of azobisisobutyronitrile added is 2% of the mass of the solution system, heat to 65°C, stir and react for 4.5 hours, and filter the reaction solution to obtain a hydrophilic PVDF material.

[0086] Comparative Example 1

[0087] This comparative example provides an offshore heavy oil high temperature produced water treatment and reinjection system, combined with Figure 1-4 As shown, its specific structure is substantially the same as the specific structure described in Example 1, and the only difference is the preparation method of the hydrophilic PVDF material for preparing the filter membrane filament 335. The specific preparation method is as follows:

[0088] Step 1: Dissolve PVDF powder in N-methyl-2-pyrrolidone, stir under nitrogen protection until completely dissolved, then add acrylic acid monomer and azobisisobutyronitrile, the amount of acrylic acid monomer added is 5% of the pretreated PVDF material, and the amount of azobisisobutyronitrile added is 2% of the mass of the solution system, heat to 65°C, stir and react for 4.5 hours, filter the reaction solution to obtain a hydrophilic PVDF material.

[0089] Comparative Example 2

[0090] This comparative example provides an offshore heavy oil high temperature produced water treatment and reinjection system, combined with Figure 1-4 As shown, its specific structure is substantially the same as the specific structure described in Example 1, and the only difference is the preparation method of the hydrophilic PVDF material for preparing the filter membrane filament 335. The specific preparation method is as follows:

[0091] Step 1: Place the PVDF powder under an electron accelerator for pre-irradiation, adjust the irradiation equipment parameters so that the irradiation dose is 10 kGy and the irradiation dose rate is 6000 Gy / s, and obtain the pre-treated PVDF material;

[0092] Step 2: Dissolve the pretreated PVDF material obtained in step 1 in N-methyl-2-pyrrolidone, stir under nitrogen protection until completely dissolved, then add acrylic acid monomer and azobisisobutyronitrile, the amount of acrylic acid monomer added is 5% of the pretreated PVDF material, and the amount of azobisisobutyronitrile added is 2% of the mass of the solution system, heat to 65°C, stir and react for 4.5 hours, and filter the reaction solution to obtain a hydrophilic PVDF material.

[0093] Comparative Example 3

[0094] This embodiment provides an offshore heavy oil high temperature produced water treatment and reinjection system, combined with Figure 1-4 As shown, its specific structure is substantially the same as the specific structure described in Example 1, and the only difference is the preparation method of the hydrophilic PVDF material for preparing the filter membrane filament 335. The specific preparation method is as follows:

[0095] Step 1: Place the PVDF powder under an electron accelerator for pre-irradiation, adjust the irradiation equipment parameters so that the irradiation dose is 300 kGy and the irradiation dose rate is 6000 Gy / s, and obtain the pre-treated PVDF material;

[0096] Step 2: Dissolve the pretreated PVDF material obtained in step 1 in N-methyl-2-pyrrolidone, stir under nitrogen protection until completely dissolved, then add acrylic acid monomer and azobisisobutyronitrile, the amount of acrylic acid monomer added is 5% of the pretreated PVDF material, and the amount of azobisisobutyronitrile added is 2% of the mass of the solution system, heat to 65°C, stir and react for 4.5 hours, and filter the reaction solution to obtain a hydrophilic PVDF material.

[0097] Comparative Example 4

[0098] This embodiment provides an offshore heavy oil high temperature produced water treatment and reinjection system, combined with Figure 1-4 As shown, its specific structure is substantially the same as the specific structure described in Example 1, and the only difference is the preparation method of the hydrophilic PVDF material for preparing the filter membrane filament 335. The specific preparation method is as follows:

[0099] Step 1: Place the PVDF powder under an electron accelerator for pre-irradiation, adjust the irradiation equipment parameters so that the irradiation dose is 75 kGy and the irradiation dose rate is 20 Gy / s, and obtain the pre-treated PVDF material;

[0100] Step 2: Dissolve the pretreated PVDF material obtained in step 1 in N-methyl-2-pyrrolidone, stir under nitrogen protection until completely dissolved, then add acrylic acid monomer and azobisisobutyronitrile, the amount of acrylic acid monomer added is 5% of the pretreated PVDF material, and the amount of azobisisobutyronitrile added is 2% of the mass of the solution system, heat to 65°C, stir and react for 4.5 hours, and filter the reaction solution to obtain a hydrophilic PVDF material.

[0101] Comparative Example 5

[0102] This embodiment provides an offshore heavy oil high temperature produced water treatment and reinjection system, combined with Figure 1-4 As shown, its specific structure is substantially the same as the specific structure described in Example 1, and the only difference is the preparation method of the hydrophilic PVDF material for preparing the filter membrane filament 335. The specific preparation method is as follows:

[0103] Step 1: Pre-irradiate the PVDF powder under an electron accelerator, adjust the parameters of the irradiation equipment so that the irradiation dose is 75 kGy and the irradiation dose rate is 30000 Gy / s, and obtain the pre-treated PVDF material;

[0104] Step 2: Dissolve the pretreated PVDF material obtained in step 1 in N-methyl-2-pyrrolidone, stir under nitrogen protection until completely dissolved, then add acrylic acid monomer and azobisisobutyronitrile, the amount of acrylic acid monomer added is 5% of the pretreated PVDF material, and the amount of azobisisobutyronitrile added is 2% of the mass of the solution system, heat to 65°C, stir and react for 4.5 hours, and filter the reaction solution to obtain a hydrophilic PVDF material.

[0105] Application Example 1

[0106] The same batch of offshore heavy oil high temperature produced water was divided into six parts, and treated by the offshore heavy oil high temperature produced water treatment and reinjection system provided by Example 3 and Comparative Examples 1-5 respectively. The suspended matter content and oil content in the reinjection water obtained by treatment were measured by the method recorded in "Q / SY DQ0605-2006 Daqing Oilfield Reservoir Water Flooding Water Quality Index and Analysis Method", and the results are shown in the following table:

[0107]

[0108]

[0109] Result analysis: By comparing the above experimental results, it can be seen that the filtration membrane made of the hydrophilic PVDF material provided by the present invention has a good filtration effect and achieves the expected purpose of the present invention.

[0110] The specific embodiments described herein are merely examples of the spirit of the present invention. Those skilled in the art may make various modifications or additions to the specific embodiments described or replace them in similar ways, but they will not deviate from the spirit of the present invention or exceed the scope defined by the appended claims.

[0111] Although this article uses more oil removal system 1, fine filtration system 2, membrane filtration system 3, waste oil treatment system 4, sludge treatment system 5, seawater desalination system 6, aeration structure 7, cyclone separator 11, flotation device 12, fine filtration raw water tank 21, self-cleaning filter 22, multi-media filter 23, walnut shell filter 24, membrane filtration raw water tank 31, security filter 32, high temperature ultrafiltration device 33, water injection buffer tank 34, water injection well 35, ultrafiltration chemical cleaning device 36, ultrafiltration backwash device 37, waste oil storage tank 41, thermal cracking device 42, oil-water separation device 43, backwash wastewater collection box 51, sedimentation tank 52, sludge concentration The terms of the tank 53, sludge filter press system 54, sludge drying equipment 55, sand filter device 61, reverse osmosis device 62, water production tank 63, dosing system 64, aeration body 71, gas hose 72, air inlet 73, gas channel 74, axial air outlet 75, radial air outlet 76, lifting structure 77, guide groove 78, guide block 79, convergence plate 7a, membrane wire limit hole 7b, clearance hole 7c, filter cavity 331, outer shell 332, mounting part 333, water outlet cavity 334, filter membrane filament 335, water production port 336, upper outlet 337, lower outlet 338, water inlet 339, etc., but the possibility of using other terms is not excluded. The use of these terms is only for the purpose of more conveniently describing and explaining the essence of the present invention; interpreting them as any additional restrictions is contrary to the spirit of the present invention.

Claims

1. An offshore heavy oil high-temperature produced water treatment and reinjection system, comprising an oil removal system (1) and a fine filtration system (2) which are interconnected, wherein the oil removal system (1) is further connected to a waste oil treatment system (4) for treating waste oil separated by the oil removal system (1), and the fine filtration system (2) is further connected to a sludge treatment system (5) for treating solid impurities separated by the fine filtration system (2), characterized in that: The end of the fine filtration system (2) away from the oil removal system (1) is also connected to a membrane filtration system (3), and the membrane filtration system (3) comprises a membrane filtration raw water tank (31), a security filter (32), a high-temperature ultrafiltration device (33) and a water injection buffer tank (34) which are connected in sequence. The membrane filtration raw water tank (31) is connected to the fine filtration system (2), and the water injection buffer tank (34) is connected to a water injection well (35).

2. The offshore heavy oil high temperature produced water treatment and reinjection system according to claim 1, characterized in that: The oil removal system (1) comprises a cyclone separator (11) connected to a high-temperature produced water source, one end of an air flotation device (12) is connected to the cyclone separator (11), and the other end is connected to a fine filtration system (2); The waste oil treatment system (4) comprises a waste oil storage tank (41), a thermal cracking device (42) and an oil-water separation device (43) which are connected in sequence; the air flotation device (12) is connected to the waste oil storage tank (41) and the waste oil separated in the air flotation device (12) is stored in the waste oil storage tank (41); the oil-water separation device (43) is connected to the air flotation device (12) and the water phase separated in the oil-water separation device (43) flows back into the air flotation device (12).

3. The offshore heavy oil high temperature produced water treatment and reinjection system according to claim 1, characterized in that: The fine filtration system (2) comprises a fine filtration raw water tank (21), a self-cleaning filter (22), a multi-media filter (23) and a walnut shell filter (24) which are connected in sequence; the fine filtration raw water tank (21) is connected to the oil removal system (1), and the walnut shell filter (24) is connected to the membrane filtration raw water tank (31).

4. The offshore heavy oil high temperature produced water treatment and reinjection system according to claim 3, characterized in that: The membrane filtration system (3) further comprises an ultrafiltration chemical cleaning device (36) and an ultrafiltration backwashing device (37) both of which are connected to the high-temperature ultrafiltration device (33); the ultrafiltration backwashing device (37) is connected to the self-cleaning filter (22), the multi-media filter (23) and the walnut shell filter (24) respectively, and the ultrafiltration backwashing device (37) can transport backwashing water to the self-cleaning filter (22), the multi-media filter (23) and the walnut shell filter (24) respectively.

5. The offshore heavy oil high temperature produced water treatment and reinjection system according to claim 3, characterized in that: The sludge treatment system (5) comprises a backwash wastewater collection tank (51), a sedimentation tank (52), a sludge concentration tank (53), a sludge filter press system (54) and a sludge drying device (55) which are connected in sequence. The self-cleaning filter (22), the multi-media filter (23) and the walnut shell filter (24) are all connected to the backwash wastewater collection tank (51), the sedimentation tank (52) is connected to the fine filtration raw water tank (21), and the water phase separated after sedimentation in the sedimentation tank (52) is transported to the fine filtration raw water tank (21).

6. The offshore heavy oil high temperature produced water treatment and reinjection system according to claim 5, characterized in that: The invention also comprises a seawater desalination system (6), wherein the seawater desalination system (6) comprises a sand filter device (61), a reverse osmosis device (62), a water production tank (63) and a dosing system (64) which are connected in sequence, wherein the reverse osmosis device (62) is connected to the sludge drying equipment (55), and the concentrated water output by the reverse osmosis device (62) is used to accelerate the removal of steam generated in the sludge drying equipment (55).

7. The offshore heavy oil high temperature produced water treatment and reinjection system according to claim 1, characterized in that: The high temperature ultrafiltration device (33) comprises an outer shell (332) having a filter cavity (331) therein; a mounting member (333) is fixedly arranged inside the outer shell (332); a water outlet cavity (334) is provided above the mounting member (333); one end of a filter membrane thread (335) is fixedly connected to the mounting member (333) and the other end is a free end; the filter cavity (331) is connected to the water outlet cavity (334) via the filter membrane thread (335); a water outlet (336) and an upper outlet (337) are also provided at the upper end of the outer shell (332); The water production port (336) is in communication with the water outlet cavity (334), the upper outlet (337) is in communication with the filtering cavity (331), the lower end of the outer shell (332) is also provided with a water inlet (339) and a lower outlet (338), both of which are in communication with the filtering cavity (331), and an aeration structure (7) is also provided in the filtering cavity (331), the aeration structure (7) is slidably connected to the outer shell (332), and one end of the aeration structure (7) extends to the outside of the outer shell (332) and is in communication with an external air source.

8. The offshore heavy oil high temperature produced water treatment and reinjection system according to claim 7, characterized in that: The aeration structure (7) comprises a cylindrical aeration body (71), on which a gas delivery hose (72) is arranged, one end of the gas delivery hose (72) away from the aeration body (71) is connected to an air inlet (73) arranged on an outer shell (332), and the air inlet (73) is connected to an external air source. A plurality of gas delivery channels (74) are provided in the aeration body (71), one end of the gas delivery channel (74) is connected to the gas delivery hose (72), and the other end of the gas delivery channel (74) passes through the top surface and the side surface of the aeration body (71) to form an axial gas outlet (75) and a radial gas outlet (76).

9. The offshore heavy oil high temperature produced water treatment and reinjection system according to claim 8, characterized in that: The bottom of the aeration body (71) is also connected to a lifting structure (77), and the side of the aeration body (71) is provided with a guide groove (78) recessed toward the inside of the aeration body (71), and the guide groove (78) is slidably connected to a guide block (79) protruding from the inner surface of the outer shell (332); The aeration structure (7) further comprises a convergence disk (7a) fixedly connected to the inner surface of the aeration body (71); the convergence disk (7a) is provided with a plurality of convergence disks (7a) arranged in sequence along the axis direction of the aeration body (71); a clearance hole (7c) penetrating the convergence disk (7a) is provided at the center position of the convergence disk (7a); the convergence disk (7a) is also provided with a plurality of membrane thread limiting holes (7b) uniformly distributed along the axis circumference of the convergence disk (7a); and the sliding aeration body (71) can allow the free end of the filter membrane thread (335) to pass through the membrane thread limiting hole (7b).

10. The offshore heavy oil high temperature produced water treatment and reinjection system according to claim 7, characterized in that: The filter membrane (335) is made of a hydrophilic PVDF material, and the hydrophilic PVDF material is prepared by the following method: Step 1: Place the PVDF powder under an electron accelerator for pre-irradiation, adjust the irradiation equipment parameters so that the irradiation dose is 20-200 kGy and the irradiation dose rate is 50-15000 Gy / s, and obtain the pre-treated PVDF material; Step 2: Dissolve the pretreated PVDF material obtained in step 1 in a strong polar organic solvent, stir under nitrogen protection until completely dissolved, then add vinyl hydrophilic monomer and initiator, heat to 50-80°C, stir and react for 3-6 hours, and filter the reaction solution to obtain a hydrophilic PVDF material.

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