An integrated oil-water separation device and method for offshore platforms

Abstract

The application discloses an integrated oil-water separation device and method for offshore platforms, a shell, a plurality of metal screen assemblies perpendicular to the axial direction of the shell are sequentially arranged in the shell to divide the shell into a plurality of separation chambers in series along the fluid flow direction, and the aperture of the metal screen assembly gradually decreases along the fluid flow direction; a water inlet is arranged at the head end of the shell and communicates with the first separation chamber; a water outlet is arranged at the tail end of the shell and communicates with the last separation chamber; at least one inclined plate coalescence separation assembly is arranged before the last separation chamber; a backwashing assembly communicating with the metal screen assembly is arranged to backwash the metal screen assembly; and a controller is electrically connected with the backwashing assembly at the output end, so that the problem that the traditional equipment relies on manual operation and is difficult to respond to working condition changes in real time is solved.

Description

Technical Field

[0001] This invention belongs to the field of marine environmental pollution prevention and control and oil and gas extraction wastewater treatment technology, and particularly relates to an integrated oil-water separation device and method for offshore platforms. Background Technology

[0002] With the expansion of offshore oil and gas exploration, the risk of crude oil leaks from production facilities is increasing. Offshore platforms have limited space and carrying capacity, making it difficult to adopt the traditional onshore oil and gas field model of "trading more equipment space for longer processing time." The commonly used three-stage treatment process of "inclined plate degreasing → aerated flotation → filtration" has the following problems: low separation efficiency and slow speed, making it difficult to cope with sudden large-scale oil spills; high chemical consumption and easy secondary pollution; equipment prone to clogging and difficult maintenance; membrane separation methods offer high precision but are prone to clogging, while media coalescence methods have insufficient separation depth; physical demulsification technologies such as energy field demulsification have high energy consumption and complex equipment; traditional equipment relies on manual operation, making it difficult to respond to real-time changes in operating conditions; and the pressure energy of the treated purified water is not recovered and utilized.

[0003] Therefore, there is an urgent need to design an integrated oil-water separation device and method for offshore platforms to solve the problems mentioned above. Summary of the Invention

[0004] The purpose of this invention is to provide an integrated oil-water separation device and method for offshore platforms, which solves the problem that traditional equipment relies on manual operation and is difficult to respond to changes in operating conditions in real time.

[0005] To achieve the above objectives, the specific technical solution of the integrated oil-water separation device and method for offshore platforms according to the present invention is as follows: An integrated oil-water separator for offshore platforms includes: The housing is internally divided into multiple series-connected separation chambers by multiple metal mesh assemblies perpendicular to the housing axis along the fluid flow direction, and the aperture of the metal mesh assemblies decreases progressively along the fluid flow direction. Water inlets are respectively located at the front end of the shell and connected to the first separation chamber; The outlet at the end of the shell and connected to the last separation chamber; At least one inclined plate coalescing separation component is disposed before the final separation chamber; A backwashing assembly connected to the metal mesh assembly for backwashing the metal mesh assembly; The controller, the output of which is electrically connected to the backwashing assembly.

[0006] Furthermore, the surfaces of the metal mesh assembly and the inclined plate coalescing and separating assembly are coated with a hydrophilic-oleophobic or oleophilic-hydrophobic coating.

[0007] Furthermore, the integrated oil-water separation device for offshore platforms also includes an energy recovery component, the inlet of which is connected in series or parallel with the outlet via pipelines, for recovering the pressure energy of the purified water.

[0008] Furthermore, the energy recovery component employs a hydraulic turbine or a pressure exchanger.

[0009] Furthermore, the material of the metal mesh assembly is selected from one or more of stainless steel, copper, nickel, titanium, and aluminum, and the aperture gradient of the metal mesh assembly is in the range of 50 mesh to 5000 mesh.

[0010] Furthermore, the integrated oil-water separation device for offshore platforms also includes a monitoring component, which includes a level sensor, an oil concentration sensor, and a differential pressure sensor. The level sensor is located at the top of the separation chamber, the oil concentration sensor is located on the water outlet side of the separation chamber, and the differential pressure sensor is located on the water inlet and outlet sides of the metal mesh assembly. The level sensor, the oil concentration sensor, and the differential pressure sensor are all electrically connected to the input terminal of the controller.

[0011] Furthermore, the backwashing assembly includes a backwashing pump, a media storage tank, and a valve group. The inlet of the backwashing pump is connected to the media storage tank, and the outlet of the backwashing pump is connected to the separation chamber downstream of each stage of the metal mesh assembly through the valve group and pipelines.

[0012] Furthermore, the output end of the energy recovery component is connected to the backwash pump via mechanical transmission or electric output to provide power to the backwash pump.

[0013] An integrated oil-water separation method for offshore platforms, employing the aforementioned integrated oil-water separation device for offshore platforms, includes the following steps: The oily wastewater flows sequentially through multiple metal mesh components with progressively smaller pore sizes under pressure differential. Each metal mesh component simultaneously performs pore size screening to intercept oil droplets, surface coalescence to break up emulsified oil into large oil droplets, and gravity-fed oil droplets to float to the top of the separation chamber to form an oil layer, thus obtaining the first fluid. The first fluid passes through the inclined plate coalescing separation component, where residual fine oil droplets collide, coalesce, and float to the surface, resulting in a deeply purified fluid. The deeply purified fluid is screened in the last separation chamber to obtain purified water, and the purified water flows through the energy recovery component to recover pressure energy when it is discharged. During operation, the controller controls the start and stop of the backwashing component based on feedback signals from the liquid level sensor, oil concentration sensor, and differential pressure sensor.

[0014] Furthermore, if the differential pressure sensor signal remains abnormal after the number of backwashing cycles reaches a preset value, the controller will issue a chemical cleaning prompt and recommend or automatically prepare a cleaning agent.

[0015] The integrated oil-water separation device and method for offshore platforms of the present invention achieves automatic backwashing by setting a backwashing component electrically connected to the controller, which solves the problem of easy clogging of metal mesh, extends continuous operation time, and reduces the frequency of manual maintenance. Moreover, the multi-stage pore size gradient metal mesh component gradually reduces the pore size along the fluid flow direction, realizing the graded capture and coalescence of oil droplets, significantly improving the separation efficiency, and can handle oil pollution of various forms, from floating oil to emulsified oil. Attached Figure Description

[0016] Figure 1 This is a schematic diagram of the internal structure of the integrated oil-water separation device for offshore platforms according to the present invention. Figure 2 This is a three-dimensional structural schematic diagram of the integrated oil-water separation device for offshore platforms according to the present invention; Figure 3 This is a control flow diagram of the integrated oil-water separation device for offshore platforms according to the present invention.

[0017] Explanation of markings in the diagram: 1. Shell; 2. Metal mesh assembly; 3. Separation chamber; 4. Inlet; 5. Outlet; 6. Inclined plate coalescing separation assembly; 7. Backwash assembly; 701. Backwash pump; 702. Medium storage tank; 703. Valve assembly; 8. Controller; 9. Energy recovery assembly; 10. Monitoring assembly; 1001. Liquid level sensor; 1002. Oil concentration sensor; 1003. Differential pressure sensor; 11. Control valve. Detailed Implementation

[0018] 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 embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0019] Those skilled in the art will understand that although some embodiments herein include certain features included in other embodiments but not others, combinations of features from different embodiments are intended to be within the scope of the invention and form different embodiments. For example, in the claims, any of the claimed embodiments can be used in any combination.

[0020] The following is a reference to the appendix. Figure 1 To be continued Figure 3 This invention describes an integrated oil-water separation device and method for offshore platforms.

[0021] like Figures 1 to 3 As shown, an integrated oil-water separator for offshore platforms includes: The housing 1 is divided into multiple series-connected separation chambers 3 by multiple metal mesh assemblies 2 perpendicular to the axial direction of the housing 1 along the fluid flow direction. The aperture of the metal mesh assemblies 2 decreases step by step along the fluid flow direction. Water inlets 4 are respectively located at the front end of the shell 1 and connected to the first separation chamber 3; The water outlet 5 at the end of the shell 1 and connected to the last separation chamber 3; At least one inclined plate coalescing separation component 6 is disposed before the final separation chamber 3; A backwashing assembly 7, connected to the metal mesh assembly 2, is used to backwash the metal mesh assembly 2. The controller 8 is electrically connected to the backwashing assembly 7.

[0022] In this embodiment, by setting the backwashing component 7 to be electrically connected to the controller 8, automatic backwashing is realized, which solves the problem of easy clogging of metal mesh, extends continuous operation time, and reduces the frequency of manual maintenance. Moreover, the multi-level aperture gradient metal mesh component 2 gradually reduces the aperture along the fluid flow direction, realizing the graded capture and coalescence of oil droplets, significantly improving the separation efficiency. It can handle various forms of oil pollution, from floating oil to emulsified oil. The entire process is physical separation without chemical additives, avoiding secondary pollution and being environmentally friendly.

[0023] Specifically, the shell 1 is a horizontal cylindrical structure or a vertical cylindrical structure to adapt to different spatial layout requirements of offshore platforms.

[0024] Specifically, at least one stage of the metal mesh assembly 2 employs a corrugated mesh structure woven from metal wires. This corrugated mesh is pressed and fixed within the frame of the metal mesh assembly 2 to increase the effective filtration area and coalescing efficiency. The metal mesh assembly 2 adopts a detachable plate-frame structure, fixed inside the housing 1 with screws. When the separation efficiency decreases due to contamination, it can be disassembled, cleaned with a chemical cleaning agent, and reinstalled after restoring its hydrophilicity. The excellent chemical stability of the metal mesh ensures a long service life for the oil-water separator, significantly reducing filter replacement costs.

[0025] Specifically, the backwashing direction of the backwashing component 7 is opposite to the normal fluid flow direction.

[0026] Specifically, the inclined plate coalescing separation component 6 consists of a set of parallel and spaced corrugated plates or flat plates, the surfaces of which are inclined at an acute angle to the horizontal direction. Fluid flows along the inclined plate surfaces in the gaps between the plates, and residual fine oil droplets collide and coalesce with the plate surfaces, floating up the plate walls to the top of the chamber. This utilizes the shallow pool principle and collision coalescing to achieve deep separation of the residual small oil droplets.

[0027] Furthermore, the surfaces of the metal mesh assembly 2 and the inclined plate coalescing separation assembly 6 are coated with a hydrophilic-oleophobic or oleophilic-hydrophobic coating to enhance the oil-water separation effect.

[0028] Furthermore, the integrated oil-water separation device for offshore platforms also includes an energy recovery component 9, the inlet of which is connected in series or parallel with the outlet 5 via pipelines, for recovering the pressure energy of the purified water.

[0029] Furthermore, the energy recovery component 9 employs a hydraulic turbine or a pressure exchanger.

[0030] Furthermore, the output end of the energy recovery component 9 is connected to the backwash pump 701 via mechanical transmission or electric output to provide power to the backwash pump 701.

[0031] In this embodiment, the energy recovery component 9 recovers the pressure energy of the purified water, reducing the overall energy consumption of the system; the energy recovery component 9 can also provide power for the backwash pump 701, further improving energy utilization efficiency.

[0032] Optionally, the hydraulic turbine may be a cross-flow turbine or a mixed-flow turbine; the pressure exchanger may be a rotary pressure exchanger or a reciprocating pressure exchanger.

[0033] Furthermore, the material of the metal mesh assembly 2 is selected from one or more of stainless steel, copper, nickel, titanium, and aluminum, and the aperture gradient range of the metal mesh assembly 2 is 50 mesh to 5000 mesh.

[0034] Preferably, a super-hydrophilic stainless steel mesh with four levels of aperture is used: the first level of aperture is 200 mesh, the second level is 500 mesh, the third level is 1000 mesh, and the fourth level is 2000 mesh.

[0035] Furthermore, the integrated oil-water separation device for offshore platforms also includes a monitoring component 10, which includes a level sensor 1001, an oil concentration sensor 1002, and a differential pressure sensor 1003. The level sensor 1001 is located at the top of the separation chamber 3 and is used to monitor the oil layer thickness at the top of each separation chamber 3. The oil concentration sensor 1002 is located on the water outlet side of the separation chamber 3 and is used to monitor the oil content on the water outlet side of each separation chamber 3. The differential pressure sensor 1003 is located on the water inlet and water outlet sides of the metal mesh assembly 2 and is used to monitor the differential pressure value on both sides of each metal mesh assembly 2. The level sensor 1001, the oil concentration sensor 1002, and the differential pressure sensor 1003 are all electrically connected to the input terminal of the controller 8 and send real-time monitoring data to the controller 8.

[0036] In this embodiment, the controller 8 monitors the differential pressure, oil concentration and oil layer thickness in real time. The controller 8 automatically controls the start and stop of the backwashing component 7 according to the feedback signal, so as to realize the automatic optimization of the device operation and respond to changes in operating conditions in real time.

[0037] Optionally, the level sensor 1001 is a radar level gauge or an ultrasonic level gauge, the oil concentration sensor 1002 is an ultraviolet fluorescence oil concentration meter or an infrared oil detector, the differential pressure sensor 1003 is a capacitive differential pressure transmitter, and the controller 8 is a programmable logic controller 8 or an embedded industrial controller 8.

[0038] Furthermore, the backwashing assembly 7 includes a backwashing pump 701, a media storage tank 702, and a valve group 703. The inlet of the backwashing pump 701 is connected to the media storage tank 702, and the outlet of the backwashing pump 701 is connected to the separation chamber 3 downstream of each stage of the metal mesh assembly 2 via the valve group 703 and pipelines. The backwashing direction is opposite to the normal fluid flow direction. The flushing medium is purified water or a chemical cleaning agent. During backwashing, the water inlet passage upstream of the metal mesh assembly 2 is closed, and the backwashing pump 701 and the corresponding valve are opened, allowing the flushing medium to flow in the opposite direction from the downstream side to the upstream side of the metal mesh assembly 2, flushing away oil and impurities adhering to the surface of the metal mesh.

[0039] Optionally, the backwash pump 701 may be a centrifugal pump or a plunger pump; the medium storage tank 702 may be an atmospheric pressure storage tank or a pressure vessel with agitation; and the valve group 703 may be an electric ball valve or a pneumatic butterfly valve.

[0040] Furthermore, a regulating valve 11 is installed on the water inlet 4 pipe, and the regulating valve 11 is electrically connected to the output terminal of the controller 8.

[0041] An integrated oil-water separation method for offshore platforms, employing the aforementioned integrated oil-water separation device for offshore platforms, includes the following steps: The oily wastewater flows sequentially through multiple metal mesh components 2 with progressively smaller pore sizes under pressure differential. Each metal mesh component 2 simultaneously performs pore size screening to intercept oil droplets, surface aggregation to break up emulsified oil into large oil droplets, and gravity-fed oil droplets to float to the top of the separation chamber 3 to form an oil layer, thus obtaining the first fluid. The first fluid passes through the inclined plate coalescing separation component 6, where residual fine oil droplets collide, coalesce, and float to the surface, resulting in a deeply purified fluid. The deeply purified fluid is screened in the last separation chamber 3 to obtain purified water. When the purified water is discharged, it flows through the energy recovery component 9 to recover pressure energy. During operation, the controller 8 controls the start and stop of the backwashing assembly 7 based on feedback signals from the level sensor 1001, oil concentration sensor 1002, and differential pressure sensor 1003. When the value monitored by the differential pressure sensor 1003 exceeds a preset threshold, the oil concentration exceeds a set value, or the oil layer thickness exceeds a warning line, the controller 8 automatically starts the backwashing system to backwash the target metal mesh assembly 2. The backwashing continues for a preset time or until the differential pressure returns to the normal range, at which point the controller 8 shuts down the backwashing system and restores the unit's normal separation process.

[0042] Furthermore, if the differential pressure sensor 1003 signal is still abnormal after the number of backwashes reaches the preset value, the controller 8 issues a chemical cleaning prompt and recommends or automatically prepares a cleaning agent.

[0043] Specifically, when the backwashing assembly 7 is chemically cleaned and regenerated, the controller 8 recommends a chemical cleaning agent ratio scheme or automatically controls the ratio device to prepare the cleaning agent based on the stored historical pollutant type data or the real-time detected pollutant components. The operator can disassemble the metal mesh assembly 2 for chemical soaking and cleaning and then reinstall it.

[0044] Furthermore, the flow rate of the oily wastewater is dynamically adjusted by the controller 8 according to the feedback signal of the differential pressure sensor 1003, thereby maintaining the differential pressure of each metal mesh assembly 2 within the optimal range and optimizing the separation effect.

[0045] Obviously, the above embodiments of the present invention are merely examples for clearly illustrating the present invention, and are not intended to limit the implementation of the present invention. Those skilled in the art can make other variations or modifications based on the above description. It is neither necessary nor possible to exhaustively describe all embodiments here. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included within the scope of protection of the claims of the present invention.

Claims

1. An integrated oil-water separation device for offshore platforms, characterized in that, include: The housing is internally divided into multiple series-connected separation chambers by multiple metal mesh assemblies perpendicular to the housing axis along the fluid flow direction, and the aperture of the metal mesh assemblies decreases progressively along the fluid flow direction. Water inlets are respectively located at the front end of the shell and connected to the first separation chamber; The outlet at the end of the shell and connected to the last separation chamber; At least one inclined plate coalescing separation component is disposed before the final separation chamber; A backwashing assembly connected to the metal mesh assembly for backwashing the metal mesh assembly; The controller, the output of which is electrically connected to the backwashing assembly.

2. The integrated oil-water separator for offshore platforms according to claim 1, characterized in that, The surfaces of the metal mesh assembly and the inclined plate coalescing and separating assembly are coated with a hydrophilic-oleophobic or oleophilic-hydrophobic coating.

3. The integrated oil-water separator for offshore platforms according to claim 1, characterized in that, It also includes an energy recovery component, the inlet of which is connected in series or parallel with the outlet via pipelines, for recovering the pressure energy of the purified water.

4. The integrated oil-water separator for offshore platforms according to claim 3, characterized in that, The energy recovery component employs a hydraulic turbine or a pressure exchanger.

5. The integrated oil-water separator for offshore platforms according to claim 1, characterized in that, The material of the metal mesh assembly is selected from one or more of stainless steel, copper, nickel, titanium, and aluminum, and the aperture gradient range of the metal mesh assembly is 50 mesh to 5000 mesh.

6. The integrated oil-water separator for offshore platforms according to claim 1, characterized in that, It also includes a monitoring component, which includes a liquid level sensor, an oil concentration sensor, and a differential pressure sensor. The liquid level sensor is located at the top of the separation chamber, the oil concentration sensor is located on the water outlet side of the separation chamber, and the differential pressure sensor is located on the water inlet and outlet sides of the metal mesh assembly. The liquid level sensor, the oil concentration sensor, and the differential pressure sensor are all electrically connected to the input terminal of the controller.

7. The integrated oil-water separator for offshore platforms according to claim 3, characterized in that, The backwashing assembly includes a backwashing pump, a media storage tank, and a valve group. The inlet of the backwashing pump is connected to the media storage tank, and the outlet of the backwashing pump is connected to the separation chamber downstream of each stage of the metal mesh assembly through the valve group and pipelines.

8. The integrated oil-water separator for offshore platforms according to claim 7, characterized in that, The output of the energy recovery component is connected to the backwash pump via mechanical transmission or electric output to provide power to the backwash pump.

9. An integrated oil-water separation method for offshore platforms, employing the integrated oil-water separation device for offshore platforms as described in any one of claims 1 to 8, characterized in that, Includes the following steps: The oily wastewater flows sequentially through multiple metal mesh components with progressively smaller pore sizes under pressure differential. Each metal mesh component simultaneously performs pore size screening to intercept oil droplets, surface coalescence to break up emulsified oil into large oil droplets, and gravity-fed oil droplets to float to the top of the separation chamber to form an oil layer, thus obtaining the first fluid. The first fluid passes through the inclined plate coalescing separation component, where residual fine oil droplets collide, coalesce, and float to the surface, resulting in a deeply purified fluid. The deeply purified fluid is screened in the last separation chamber to obtain purified water, and the purified water flows through the energy recovery component to recover pressure energy when it is discharged. During operation, the controller controls the start and stop of the backwashing component based on feedback signals from the liquid level sensor, oil concentration sensor, and differential pressure sensor.

10. The integrated oil-water separation method for offshore platforms according to claim 9, characterized in that, If the differential pressure sensor signal remains abnormal after the number of backwashes reaches the preset value, the controller will issue a chemical cleaning prompt and recommend or automatically prepare a cleaning agent.

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