An oil-water separation method and an oil-water separation device

Abstract

This application provides an oil-water separation method and an oil-water separation device. By sequentially subjecting the produced fluid from the oilfield to flow stabilization, magnetic field modification, and electromagnetic induction heating, oil-water separation is promoted. The solution presented in this application is a new integrated treatment technology utilizing flow stabilization, magnetic field modification, and electromagnetic induction heating of the oil layer, which can significantly accelerate oil-water separation. It features a compact structure, low cost, high degree of electrification, and high efficiency and environmental friendliness.

Description

Technical Field

[0001] This application relates to produced fluid treatment technology in oilfield surface engineering, and particularly to, but not limited to, an oil-water separation method based on steady flow, magnetic field modification and electromagnetic induction heating. Background Technology

[0002] Oilfield produced fluids are a mixture of oil, gas, and water, and oil-water separation is a crucial task in oilfield surface engineering. Three-phase separators, free water removers, and thermochemical settlers are commonly used equipment for oil-water separation. Appropriate internal components can enhance separation and reduce the external dimensions of the separator.

[0003] The fluid entering the separator experiences unstable flow as it passes through the inlet components, causing turbulence in the internal flow field. Flow stabilizers can stabilize the flow field, eliminating or mitigating channeling, short-circuit flow, and eddies, thereby improving the separator's separation efficiency. Due to their large size, flow stabilizers solely for stabilizing flow are not widely used. Increasing temperature can reduce the stability of oil-water emulsions and improve oil-water separation. Heating can reduce crude oil viscosity and increase the solubility of emulsifiers, weakening the interfacial film strength. Magnetic field modification can promote oil-water separation. Flow stabilization, magnetic field modification, and electromagnetic induction heating can all promote oil-water separation; currently, there is no method to simultaneously achieve all three functions, and a compact, multifunctional, integrated internal component has not yet been developed. Summary of the Invention

[0004] The following is an overview of the subject matter described in detail herein. This overview is not intended to limit the scope of protection of this application.

[0005] This application provides an oil-water separation method and apparatus based on steady flow, magnetic field modification, and electromagnetic induction heating. By sequentially subjecting the produced fluid from the oilfield to steady flow, magnetic field modification, and electromagnetic induction heating, oil-water separation is promoted. This significantly accelerates oil-water separation. It features a compact structure, low cost, high degree of electrification, and high efficiency and environmental friendliness.

[0006] This application provides an oil-water separation device, comprising:

[0007] Two or more nested cylindrical bodies allow an oil-water mixture to flow in the space between adjacent cylindrical bodies and inside the cylindrical bodies.

[0008] A magnetic field generating module is provided in the inner wall or on the inner wall surface of the cylindrical body; a heating module is provided in the inner wall or on the inner wall surface of the cylindrical body, and the heating module is located downstream of the magnetic field generating module.

[0009] In one embodiment provided in this application, the magnetic field generating module and the heating module may be located on the outer wall surface of the oil-water separator.

[0010] In one embodiment provided in this application, the oil-water mixture can be an oilfield produced fluid, which can be a water-in-oil emulsion or an oil-in-water emulsion.

[0011] In one embodiment provided in this application, the number of layers of the sleeved cylindrical body is 5 to 25. The flow is stabilized by the multi-layered cylindrical body formed by the sleeved body. The distance between the cylinders can be equal or unequal.

[0012] In one embodiment provided in this application, the cylindrical body includes a first cylindrical body with a circular cross-section and a second cylindrical body with a D-shaped cross-section.

[0013] In one embodiment provided in this application, the first cylindrical body is located inside the second cylindrical body;

[0014] The number of layers of the first cylindrical body is 4 to 20.

[0015] The number of layers of the second cylindrical body is from 1 to 5.

[0016] In one embodiment provided in this application, the angle x between the axes of the different cylindrical bodies is 0°≤x<90°;

[0017] Alternatively, different cylindrical bodies may be coaxial.

[0018] In one embodiment provided in this application, the magnetic field generating module includes a solenoid surrounding the cylindrical body;

[0019] In one embodiment provided in this application, a magnetic field generating module is used to perform magnetic field modification treatment on an oil-water mixture. The magnetic field is generated by a solenoid carrying direct current, and the magnitude and direction of the magnetic induction intensity can remain unchanged.

[0020] In one embodiment provided in this application, the solenoid in the magnetic field generating module is coaxial with the cylindrical body.

[0021] In one embodiment provided in this application, the number of layers of the solenoid that generates the magnetic field can be the same as the number of layers of the cylindrical body, and can be the same diameter as the cylindrical body (i.e., one solenoid corresponds to one cylindrical body).

[0022] In one embodiment provided in this application, the heating module includes a magnetic component and a solenoid (the solenoid is formed by winding a wire) surrounding the cylindrical body; the heating module is configured to heat the magnetic component through electromagnetic induction.

[0023] In one embodiment provided in this application, the solenoid of the heating module is coaxial with the cylindrical body.

[0024] In one embodiment provided in this application, the oil-water mixture in the oil-water separator flows in a horizontal direction; in this application, the horizontal direction is the direction relative to the axis of the cylindrical body of the oil-water separator.

[0025] In one embodiment provided in this application, the cross-section of the magnetic component (the cross-section being a plane perpendicular to the cylinder axis) is any one or more of a circular ring, a semi-circular ring, a minor arc ring, and a major arc ring. A major arc ring is used when processing water-in-oil emulsions, and a minor arc ring is used when processing oil-in-water emulsions. The arc length of the cross-section can also be calculated based on the water content of the produced fluid, so that the magnetic component only heats the upper oil layer.

[0026] In one embodiment provided in this application, the magnetic component is heated using the principle of electromagnetic induction, and then the heat is transferred to the oil layer. When the oil-water mixture flows through the heating module, the oil-water mixture (oilfield produced fluid) may have already separated into layers to a certain extent. Heating causes the temperature of the upper oil layer to rise from below the wax precipitation point to above the wax melting point. The temperature of the lower water layer does not rise or rises only slightly, with the temperature rise ranging from 0°C to 4°C.

[0027] In one embodiment provided in this application, the number of magnetic component layers in the heating module is the same as that of the cylindrical body, and the magnetic component has the same diameter as the cylindrical body. The magnetic component generates a magnetic field in the internal space, and the oil-water mixture also plays a role in magnetic field modification when it flows through the ferromagnetic component.

[0028] In one embodiment provided in this application, the strength and direction of the magnetic field induced in the internal space of the magnetic component are variable.

[0029] In one embodiment provided in this application, the oil-water separator is a compact, multifunctional, and electrically explosion-proof oil-water separator.

[0030] In another aspect, this application provides an oil-water separation method using the aforementioned oil-water separation apparatus, comprising:

[0031] When the oil-water mixture passes through the magnetic field generating module, the temperature of the oil-water mixture is not higher than the wax precipitation point of the oil phase.

[0032] When the oil-water mixture passes through the heating module, the temperature of the oil-water mixture is above the melting point of the oil phase.

[0033] The oil-water separation method applicable to the above-mentioned apparatus provided in this application includes the following steps:

[0034] S100: Produced fluid X is obtained by stabilizing the flow of produced fluid from the oilfield;

[0035] S200: The produced fluid X from the oilfield is modified by magnetic field treatment at a temperature below the wax precipitation point to obtain produced fluid Y;

[0036] S300: The temperature of the upper oil layer of produced fluid Y rises above the melting point of the oil phase. Simultaneously, produced fluid Y undergoes magnetic field modification treatment; and the flow of produced fluid is stabilized.

[0037] This application employs a novel integrated treatment technology combining flow stabilization, magnetic field modification, and electromagnetic induction heating, which can significantly accelerate oil-water separation. This method features a compact structure, small footprint, low equipment investment, heating only the oil layer, prevention of airflow interference, low cost and high efficiency, low carbon footprint, and high degree of electrification. It lays the foundation for the application and promotion of integrated flow stabilization, magnetic field modification, and electromagnetic induction heating in accelerated oil-water separation through engineering projects.

[0038] Other features and advantages of this application will be set forth in the description which follows, and will be apparent in part from the description, or may be learned by practicing the application. Other advantages of this application may be realized and obtained by means of the methods described in the description. Attached Figure Description

[0039] The accompanying drawings are used to provide an understanding of the technical solutions of this application and constitute a part of the specification. They are used together with the embodiments of this application to explain the technical solutions of this application and do not constitute a limitation on the technical solutions of this application.

[0040] Figure 1 This is a process flow diagram of the integrated treatment of current stabilization, magnetic field modification and electromagnetic induction heating in the embodiments of this application.

[0041] Figure 2 This is an overall schematic diagram of the integrated treatment device for flow stabilization, magnetic field modification and electromagnetic induction heating disclosed in this application (view parallel to the flow direction of the oil-water mixture, without showing the magnetic field generation module and the heating module).

[0042] Figure 3 This is a cross-sectional schematic diagram of the cylindrical body of each layer of the integrated treatment device for stabilizing current, modifying magnetic field and electromagnetic induction heating disclosed in this application.

[0043] Figure 4 This is a cross-sectional schematic diagram of the ferromagnetic component of one layer of the first cylindrical body of the integrated treatment device for current stabilization, magnetic field modification and electromagnetic induction heating disclosed in this application. Figure 4 (a) in the above can be applied to water-in-oil emulsions, and the cross-section of the magnetic component can be a circular ring with an arc. Figure 4 (b) can be applied to water-in-oil emulsions, and the cross-section of the magnetic component can be a minor arc ring.

[0044] Reference numerals in the attached diagram: 1. Current stabilization zone; 2. Magnetic treatment + current stabilization zone; 3. Electromagnetic heating + magnetic treatment + current stabilization zone; 4. Insulating material; 5. Magnetic treatment wire; 6. Electromagnetic heating wire; 7. Ferromagnetic component. Detailed Implementation

[0045] To make the objectives, technical solutions, and advantages of this application clearer, the embodiments of this application are described in detail below. It should be noted that, unless otherwise specified, the embodiments and features described in these embodiments can be arbitrarily combined with each other.

[0046] like Figure 1 As shown, this oil-water separation method may include the following steps:

[0047] S100 uses a multi-layer cylindrical shell to stabilize the flow of produced fluid from the oilfield, resulting in produced fluid X (corresponding to the stable flow zone 1).

[0048] S200, at a temperature below the wax precipitation point of crude oil, applies magnetic field treatment to the oilfield produced fluid flowing through the solenoid; simultaneously, it stabilizes the flow of the oilfield produced fluid flowing through the solenoid. That is, at temperature Y, the oilfield produced fluid X flowing through the solenoid is subjected to magnetic field treatment and flow stabilization to obtain oilfield produced fluid Y (corresponding to magnetic treatment + flow stabilization zone 2).

[0049] S300 uses electromagnetic induction heating of a ferromagnetic component. When oilfield produced fluid flows through the heated ferromagnetic component, the temperature of the upper oil layer rises above the melting point of wax, while the temperature of the lower water layer remains almost unchanged. Simultaneously, the oilfield produced fluid flowing through the ferromagnetic component undergoes flow stabilization and magnetic field modification treatment. That is, due to the electromagnetic induction heating of the ferromagnetic component, the temperature of the upper oil layer flowing through the heated ferromagnetic component increases from Y to Z. At the same time, the oilfield produced fluid Y undergoes flow stabilization and magnetic field modification treatment, resulting in oilfield produced fluid Z (corresponding to electromagnetic heating + magnetic treatment + flow stabilization zone 3).

[0050] After being treated with stabilization, magnetic field modification and electromagnetic induction heating, the water content in oil produced fluid Z was significantly lower than that in oil produced fluid X, and the oil content in water in oil produced fluid Z was significantly lower than that in oil produced fluid X, thus improving the oil-water separation effect.

[0051] like Figure 2 and Figure 3 As shown in the figure, an oil-water separation device is provided in this application embodiment, including:

[0052] Two or more nested cylindrical bodies; an oil-water mixture flows in the space between adjacent cylindrical bodies and inside the cylindrical bodies;

[0053] A magnetic field generating module is installed in the inner wall of the cylindrical body; a heating module is installed in the inner wall of the cylindrical body.

[0054] The heating module is located downstream of the magnetic field generating module.

[0055] In an exemplary embodiment, the magnetic field generating module and the heating module may be located on the outer wall surface of the oil-water separation device.

[0056] In an exemplary embodiment, the magnetic field generating module and the heating module may be located in the outer wall of the oil-water separator.

[0057] In one exemplary embodiment, the magnetic field generating module and the heating module correspond one-to-one with the cylindrical body, or one magnetic field generating module and / or heating module may correspond to multiple cylindrical bodies.

[0058] In an exemplary embodiment, the oil-water mixture can be an oilfield produced fluid, which can be a water-in-oil emulsion or an oil-in-water emulsion.

[0059] like Figure 2 As shown, the number of layers of the nested cylindrical bodies is 5 to 25. The flow is stabilized by the multi-layered cylindrical bodies formed by the nesting. The distance between the cylinders can be equal or unequal.

[0060] like Figure 2 As shown, the cylindrical body includes a first cylindrical body with a circular cross-section and a second cylindrical body with a D-shaped cross-section. The cross-section is a surface perpendicular to the axis of the cylindrical body.

[0061] like Figure 2 As shown, the first cylindrical body is located inside the second cylindrical body;

[0062] The number of layers of the first cylindrical body can be from 4 to 20.

[0063] The number of layers of the second cylindrical body can be from 1 to 5.

[0064] like Figure 2 As shown, the angle between the axes of the different cylindrical bodies is 0° to no more than 90°; or, the different cylindrical bodies are coaxial.

[0065] In an exemplary embodiment, the different cylindrical bodies have different axes.

[0066] like Figure 3 As shown, the magnetic field generating module includes a solenoid containing magnetically processed wires 5 that surrounds the cylindrical body; the magnetic field generating module and the cylindrical body can be in one-to-one correspondence, or multiple cylindrical bodies can correspond to the same magnetic field generating module, or one cylindrical body can correspond to multiple magnetic field generating modules.

[0067] In an exemplary embodiment, the number of solenoids that generate the magnetic field can be the same as the number of layers of the cylindrical body, and can be the same diameter as the cylindrical body.

[0068] The magnetic field generation module is used to perform magnetic field modification treatment on oil-water mixtures. The magnetic field is generated by a solenoid carrying direct current, and the magnitude and direction of the magnetic induction intensity can remain unchanged.

[0069] like Figure 3 As shown, the solenoid and the cylindrical body in the magnetic field generating module can be coaxial or at a certain angle, so that the magnetic field generating module can better separate the oil-water mixture.

[0070] like Figure 3 As shown, the heating module includes a magnetic component and a solenoid surrounding the cylindrical body; the wire inside the solenoid in the heating module is an electromagnetic heating wire 6; the heating module is configured to heat the magnetic component through electromagnetic induction. The heating modules and cylindrical bodies can be in one-to-one correspondence, or multiple cylindrical bodies can correspond to one heating module, or one cylindrical body can correspond to multiple heating modules.

[0071] In an exemplary embodiment, a solenoid may surround a cylinder, or a solenoid may surround multiple cylinders, or there may be a one-to-one correspondence between the solenoid and the cylinder it surrounds.

[0072] In an exemplary embodiment, the axis of the solenoid of the heating module is coaxial with the cylindrical body, or at a certain angle, so that the heating module can better separate the oil-water mixture.

[0073] like Figure 3 As shown, the oil-water mixture in the oil-water separator flows horizontally.

[0074] like Figure 4 As shown, the cross-section of the magnetic component is any one or more of a circular ring, a semi-circular ring, a minor arc ring, and a major arc ring. A major arc ring is used when processing water-in-oil emulsions, and a minor arc ring is used when processing oil-in-water emulsions. The arc length of the cross-section can also be calculated based on the water content of the produced fluid, so that the magnetic component only heats the upper oil layer.

[0075] The magnetic components are heated using the principle of electromagnetic induction, and the heat is then transferred to the oil layer. When the oil-water mixture flows through the heating module, the oil-water mixture (oilfield produced fluid) may have already separated into layers to a certain extent. Heating raises the temperature of the upper oil layer from below the wax precipitation point to above the wax melting point. The temperature of the lower water layer does not rise or rises only slightly, with the temperature rise ranging from 0°C to 4°C.

[0076] In an exemplary embodiment, the number of magnetic component layers in the heating module is the same as that of the cylindrical body, and the magnetic component has the same diameter as the cylindrical body. The magnetic component generates a magnetic field in the internal space, and the oil-water mixture also plays a role in magnetic field modification when it flows through the ferromagnetic component.

[0077] In an exemplary embodiment, the strength and direction of the magnetic field induced in the internal space of the magnetic component are variable.

[0078] In an exemplary embodiment, the oil-water separator is a compact, multifunctional, and electrically explosion-proof oil-water separator.

[0079] This application also provides a method for accelerating oil-water separation, including: sequentially subjecting the produced fluid from the oilfield to flow stabilization, magnetic field modification, and electromagnetic induction heating to promote oil-water separation.

[0080] In this embodiment, current stabilization, magnetic field modification treatment, and electromagnetic heating are performed sequentially within a compact, multifunctional, and integrated internal component.

[0081] The technical solution provided in this application can be used for oilfield produced fluids with a comprehensive water content ranging from 0.5% to 75%.

[0082] An exemplary implementation:

[0083] The produced fluid from the oilfield was selected as an oil-in-water emulsion with a total water content of 55%.

[0084] The current stabilization system employs a multi-layered cylindrical structure, with coaxial layers and a minimum spacing of 100mm between adjacent cylindrical sections. The cylindrical sections are made of insulating material, which can be high-density polyethylene. Figure 2 The cylindrical separator shown has 8 layers. The inner cylindrical layer has a circular cross-section and 6 layers. The outer cylindrical layer has a D-shaped cross-section and 2 layers. Oilfield produced fluid is a mixture of oil, gas, and water. The presence of gas in the oil-water mixture will affect the oil-water separation efficiency. Since the gas density is less than that of oil and water, most of it accumulates in the upper part of the horizontal separator. Therefore, a D-shaped cross-section for the outer cylindrical layer can be selected to allow space for gas flow.

[0085] The magnetic field modification treatment temperature is 5°C below the wax precipitation point of the crude oil. For example... Figure 3 As shown, in a specific implementation of this application, a constant magnetic field (with the magnitude and direction of the magnetic induction intensity remaining unchanged) is generated by a solenoid carrying direct current.

[0086] like Figure 3 As shown, a cylindrical body corresponds to a solenoid; the oilfield produced fluid also plays a role in stabilizing the flow by passing through a constant magnetic field.

[0087] A time-varying magnetic field is generated using a time-varying current, which induces a current in the ferromagnetic component, thus heating the ferromagnetic component (carbon steel) using the principle of electromagnetic induction. Through convection and conduction, the ferromagnetic component transfers heat to the oil layer in the oilfield produced fluid, causing the temperature of the upper oil layer to rise from 5°C below the wax precipitation point to 5°C above the wax melting point; the temperature of the lower water layer rises from 0°C to 4°C.

[0088] The produced fluid from the oilfield is an oil-in-water emulsion with a total water content of 55%; the oil-in-water emulsion has a high water content, with a higher water layer in the lower part. For example... Figure 4 As shown in (b), the lower insulating material 4 cannot induce current, meaning it cannot be heated by electromagnetic induction; consequently, the lower water layer hardly heats up. The upper ferromagnetic component with a short-circuit ring can induce current, meaning it can be heated by electromagnetic induction. Heat is then transferred to the oil layer through convection and heat transfer. The cross-sectional arc length is calculated based on the water content of the produced fluid to ensure that the ferromagnetic component only heats the upper oil layer.

[0089] like Figure 3 As shown, the ferromagnetic component has the same diameter as the cylindrical body, and the oilfield produced fluid flowing through the ferromagnetic component also plays a role in stabilizing the flow.

[0090] Without stabilization and magnetic field modification, the water content of crude oil decreased from 55% to 41% when heated to the same temperature. After the integrated treatment described in this application, the water content of crude oil decreased from 55% to 19%, improving the dehydration effect by 22 percentage points. Because the treatment method provided in this application only heats oil layers with lower comparative heat capacity, it can save 65% of energy consumption. Furthermore, it uses electric induction heating, which does not consume fuel gas or fuel oil, resulting in a high degree of electrification and low carbon footprint. The integrated treatment device provided in this application has a compact structure, saving 50% of the floor space compared to conventional devices.

[0091] While the embodiments disclosed in this application are as described above, the content is merely for the purpose of facilitating understanding of this application and is not intended to limit this application. Any person skilled in the art to which this application pertains may make any modifications and changes in the form and details of the implementation without departing from the spirit and scope disclosed in this application; however, the scope of protection of this application shall still be determined by the scope defined in the appended claims.

Claims

1. An oil-water separation device, characterized in that, include: Two or more nested cylindrical bodies allow an oil-water mixture to flow in the space between adjacent cylindrical bodies and inside the cylindrical bodies; the inner wall of each cylindrical body is provided with a magnetic field generating module and a heating module, with the heating module located downstream of the magnetic field generating module; The magnetic field generating module includes a solenoid surrounding the cylindrical body; when the oil-water mixture passes through the magnetic field generating module, the produced fluid from the oilfield is subjected to magnetic field modification treatment at a temperature below the wax precipitation point of the oil-water mixture. The heating module includes a magnetic component and a solenoid surrounding the cylindrical body; the cross-sectional arc length is calculated based on the water content of the oilfield produced fluid, so that the magnetic component only heats the upper oil layer; the heating module is configured to heat the magnetic component through electromagnetic induction. The oil-water mixture is an oilfield produced fluid; the oilfield produced fluid is a mixture of oil, gas, and water. The oil-water mixture in the oil-water separator flows in a horizontal direction, which is the axial direction of the cylindrical body of the oil-water separator. The cylindrical body includes a first cylindrical body with a circular cross-section and a second cylindrical body with a D-shaped cross-section; The number of layers of the embedded cylindrical body ranges from 5 to 25. The first cylindrical body is located inside the second cylindrical body; The number of layers of the first cylindrical body is 4 to 20. The number of layers of the second cylindrical body is from 1 to 5.

2. The oil-water separation device according to claim 1, characterized in that, The angle x between the axes of the different cylindrical bodies is 0°≤x<90°.

3. The oil-water separation device according to claim 1, characterized in that, The different cylindrical bodies are coaxial.

4. The oil-water separation device according to claim 1 or 2, characterized in that, The solenoid of the magnetic field generating module is coaxial with the cylindrical body.

5. The oil-water separation device according to claim 1 or 2, characterized in that, The solenoid of the heating module is coaxial with the cylindrical body.

6. The oil-water separation device according to claim 1 or 2, characterized in that, The cross-section of the magnetic component is selected from any one or more of a semi-circular ring, a minor arc ring, and a major arc ring.

7. The oil-water separation device according to claim 6, characterized in that, When processing water-in-oil emulsions, the cross-section of the magnetic component is a superior arc ring; when processing oil-in-water emulsions, the cross-section of the magnetic component is a inferior arc ring.

8. An oil-water separation method, using the oil-water separation apparatus according to any one of claims 1 to 7, characterized in that, include: When the oil-water mixture passes through the magnetic field generating module, the produced fluid from the oilfield is subjected to magnetic field modification treatment at a temperature below the wax precipitation point of the oil-water mixture. When the oil-water mixture passes through the heating module, the temperature of the oil-water mixture is above the melting point of the oil phase.

9. The method according to claim 8, characterized in that, Includes the following steps: S100: Produced fluid X is obtained by stabilizing the flow of produced fluid from the oilfield; S200: The produced fluid X from the oilfield is modified by magnetic field treatment at a temperature below the wax precipitation point to obtain produced fluid Y; S300: The temperature of the upper oil layer of the produced fluid Y is raised to above the melting point of the oil phase. At the same time, the produced fluid Y is subjected to magnetic field modification treatment; and the flow of the produced fluid is stabilized.

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