An oilfield produced liquid demulsification and dehydration device and a demulsification and dehydration method

Abstract

The application provides a method and device for demulsification and dehydration of oilfield produced liquid. The device comprises a heating zone, a magnetic treatment zone, an acoustic treatment zone and an electro-magnetic-acoustic comprehensive treatment zone; the oilfield produced liquid sequentially passes through the heating zone, the magnetic treatment zone, the acoustic treatment zone and the electro-magnetic-acoustic comprehensive treatment zone; a magnetic field exists in the magnetic treatment zone, and an acoustic field exists in the acoustic treatment zone; an electric field, a magnetic field and an acoustic field simultaneously exist in the electro-magnetic-acoustic comprehensive treatment zone. The oilfield produced liquid sequentially undergoes heating, magnetic modification and ultrasonic bond breaking, and then is subjected to demulsification and sedimentation and oil-water separation under the synergistic action of the electric field, the magnetic field and the acoustic field. The system and process have the characteristics of synergistic treatment, compact layout, short process, high efficiency, low investment, easy operation, low operation cost, high electrification rate and low carbon emission.

Description

Technical Field

[0001] This application relates to crude oil processing technology in oilfield surface engineering, and more particularly to an oilfield produced fluid demulsification and dehydration device and a demulsification and dehydration method based on multi-physics field coupling processing. Background Technology

[0002] Shale oil and tight oil have become the main battleground for oilfield development and construction, with annual production expected to reach tens of millions of tons; chemical flooding (polymer flooding, ternary composite flooding) production will remain above 10 million tons per year. The produced fluids from shale oil and tight oil fields contain guar gum, while chemical flooding produced fluids contain polymers and surfactants, leading to severe emulsification and increased oil-water interface film strength, making crude oil demulsification and dehydration treatment extremely difficult. With the increasing deterioration of resources and the growing demand for new development methods to improve the recovery rate of old oilfields, oilfield produced fluid treatment technology faces increasingly severe challenges.

[0003] The interfacial tension of complex produced fluids from shale oil and chemical flooding is much lower than that of conventional produced fluids. With the oil-water interface area remaining constant, reducing the interfacial tension lowers the free energy of the oil-water interface, thereby promoting emulsion formation. The lower the interfacial tension, the higher the thermodynamic stability of the emulsion. The viscoelastic interfacial film surrounding the dispersed phase has high mechanical strength, creating a kinetic barrier to emulsion coalescence; that is, the interfacial film effectively prevents droplet coalescence, stabilizing the emulsion. Although polymers are insoluble in the oil phase, they can interact with the hydrophilic groups of surfactants, increasing the repulsive force and steric hindrance between interfacial films, enhancing the interfacial film strength. Furthermore, polymers can increase the viscosity of the interfacial film, slowing down the drainage process. Fracturing fluids are complex in composition, consisting of thickeners (such as hydroxypropyl guar gum), crosslinking agents, regulators, clay stabilizers, drainage aids, and breaker agents. After large-scale fracturing is completed and the well is put into production, most of the fracturing fluid enters the production system along with the produced fluid. Guar gum, gel fragments, and clay particles in the fracturing flowback fluid adsorb onto the oil-water interface, increasing the interfacial film strength and making demulsification difficult. Complex produced fluid emulsions have an average particle size less than half that of conventional produced fluids, exhibiting higher dispersion and stability. According to Stokes' law of settling, the settling velocity of small water droplets in crude oil is proportional to the square of the droplet diameter. Simultaneously, as the droplet diameter decreases, the viscosity of the emulsion increases, leading to a decrease in droplet collision frequency and coalescence rate, thus enhancing stability. The electrical conductivity of complex produced fluids from shale oil and chemical flooding is 3 to 5 times that of conventional produced fluids, resulting in high operating current, low breakdown voltage, easy short circuits between electrodes, and frequent electric field collapse during electro-dehydration.

[0004] The traditional processing technologies and equipment currently used have long processes, high investment, high operating costs, high fuel (natural gas or fuel oil) consumption, high carbon emissions, and are difficult to control dehydration indicators. They are also unstable in operation across electric fields and can no longer meet the requirements for low-cost and efficient treatment of complex produced fluids in the future. There is an urgent need to explore breakthrough technologies. Summary of the Invention

[0005] 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.

[0006] In the first aspect, this application provides an oilfield produced fluid demulsification and dehydration device, comprising: a heating zone, a magnetic treatment zone, an acoustic treatment zone, and an electro-magnetic-acoustic integrated treatment zone;

[0007] The heating zone, the magnetic treatment zone, the acoustic treatment zone, and the electro-magnetic-acoustic integrated treatment zone are connected in sequence;

[0008] The magnetic processing area is configured to provide a magnetic field, and the acoustic processing area is configured to provide a sound field;

[0009] The electro-magnetic-acoustic integrated processing area is configured to provide electric, magnetic, and acoustic fields.

[0010] In an oilfield produced fluid demulsification and dehydration device provided in this application, the heating zone is electrically heated; the electric heating method includes any one or both of resistance heating and electromagnetic induction heating.

[0011] In the oilfield produced fluid demulsification and dehydration device provided in this application, the sound field type of the sound treatment zone is an ultrasonic sound field;

[0012] In the oilfield produced fluid demulsification and dehydration device provided in this application, the type of sound field provided by the sound treatment zone is a standing wave or a traveling wave.

[0013] In the oilfield produced fluid demulsification and dehydration device provided in this application, the magnetic field provided by the magnetic treatment zone is a constant magnetic field.

[0014] In the oilfield produced fluid demulsification and dehydration device provided in this application, the electric field provided by the electro-magnetic-acoustic integrated treatment zone is an alternating electric field.

[0015] In the oilfield produced fluid demulsification and dehydration device provided in this application, the magnetic field provided by the electro-magnetic-acoustic integrated treatment zone is an alternating magnetic field.

[0016] In the oilfield produced fluid demulsification and dehydration device provided in this application, the type of sound field provided by the electro-magnetic-acoustic integrated treatment zone is any one or both of standing waves and traveling waves.

[0017] Secondly, this application provides a demulsification and dehydration method using the above-mentioned apparatus, wherein the conductivity of the oilfield produced fluid is 5 mS / cm to 20 mS / cm, optionally, the interfacial tension of the oilfield produced fluid is 0.01 mN / m to 5 mN / m, optionally, the Zeta potential of the oilfield produced fluid is 50 mV to 80 mV, and optionally, the average particle size of the emulsion in the oilfield produced fluid is 1 μm to 15 μm.

[0018] In a demulsification and dehydration method provided in this application, the oilfield produced fluid contains any one or more of amide polymers, biopolysaccharide gums, surfactants, guar gum fracturing flowback fluid, and slickwater fracturing flowback fluid.

[0019] In the demulsification and dehydration method provided in this application, after the oilfield produced fluid flows through the heating zone, the temperature of the oilfield produced fluid is at least 15°C higher than the pour point of the crude oil in the oilfield produced fluid.

[0020] In a demulsification and dehydration method provided in this application, after the oilfield produced fluid flows through the heating zone, the temperature of the oilfield produced fluid is at least 15°C to 25°C higher than the pour point of the crude oil in the oilfield produced fluid;

[0021] In the demulsification and dehydration method provided in this application, the sound field frequency provided by the sound treatment zone is 20kHz to 100kHz;

[0022] In the demulsification and dehydration method provided in this application, the acoustic treatment zone provides an acoustic field power of 10 kW / m². 2 Up to 25kW / m 2 ;

[0023] In the demulsification and dehydration method provided in this application, the average magnetic induction intensity of the magnetic field provided by the magnetic treatment zone is 1T to 2.5T;

[0024] In the demulsification and dehydration method provided in this application, the frequency of the electric field provided by the electro-magnetic-acoustic integrated processing zone is not less than 1 kHz;

[0025] In the demulsification and dehydration method provided in this application, the average electric field strength of the electric field provided by the electro-magnetic-acoustic integrated treatment zone is not less than 100kV / m;

[0026] In the demulsification and dehydration method provided in this application, the average electric field strength of the electric field provided by the electro-magnetic-acoustic integrated treatment zone is 100kV / m to 500kV / m;

[0027] In the demulsification and dehydration method provided in this application, the ratio of the frequency of the magnetic field provided by the electro-magnetic-acoustic integrated processing zone to the frequency of the electric field provided by the electro-magnetic-acoustic integrated processing zone is (1 to 2):(1 to 2).

[0028] In the demulsification and dehydration method provided in this application, the frequency of the magnetic field provided by the electro-magnetic-acoustic integrated processing zone is in a ratio of 1:1 to the frequency of the electric field provided by the electro-magnetic-acoustic integrated processing zone.

[0029] In the demulsification and dehydration method provided in this application, the direction of the magnetic field provided by the electro-magnetic-acoustic integrated processing zone forms an angle of 0° to 360° with the direction of the electric field provided by the electro-magnetic-acoustic integrated processing zone;

[0030] In the demulsification and dehydration method provided in this application, the direction of the magnetic field provided by the electro-magnetic-acoustic integrated processing zone is 90° with the direction of the electric field provided by the electro-magnetic-acoustic integrated processing zone;

[0031] In the demulsification and dehydration method provided in this application, the average magnetic induction intensity of the magnetic field provided by the electro-magnetic-acoustic integrated processing zone is not higher than 1T;

[0032] In the demulsification and dehydration method provided in this application, the average magnetic induction intensity of the magnetic field provided by the electro-magnetic-acoustic integrated processing zone is 0.2T to 1T;

[0033] In the demulsification and dehydration method provided in this application, the ratio of the frequency of the sound field provided by the electro-magnetic-acoustic integrated processing zone to the frequency of the electric field provided by the electro-magnetic-acoustic integrated processing zone is (1 to 2):(1 to 2).

[0034] In the demulsification and dehydration method provided in this application, the ratio of the frequency of the sound field provided by the electro-magnetic-acoustic integrated processing zone to the frequency of the electric field provided by the electro-magnetic-acoustic integrated processing zone is 1:1;

[0035] In the demulsification and dehydration method provided in this application, the standing wave vibration direction of the sound field provided by the electro-magnetic-acoustic integrated processing zone forms an angle of 0° to 360° with the direction of the electric field provided by the electro-magnetic-acoustic integrated processing zone.

[0036] In the demulsification and dehydration method provided in this application, the standing wave vibration direction of the sound field provided by the electro-magnetic-acoustic integrated processing zone is the same as the direction of the electric field provided by the electro-magnetic-acoustic integrated processing zone;

[0037] In the demulsification and dehydration method provided in this application, the average sound field power of the sound field provided by the electro-magnetic-acoustic integrated processing zone is not higher than 10 kW / m. 2 ;

[0038] In the demulsification and dehydration method provided in this application, the average sound field power of the sound field provided by the electro-magnetic-acoustic integrated processing zone is 2kW / m². 2 Up to 10kW / m 2 .

[0039] In a demulsification and dehydration method provided in this application, the residence time of the oilfield produced fluid in the magnetic treatment zone is 1 min to 5 min, the residence time in the acoustic treatment zone is 2 min to 10 min, and the residence time in the electro-magnetic-acoustic integrated treatment zone is 20 min to 80 min.

[0040] This application addresses complex produced fluids by employing a novel multi-physics field coupling processing technology, which can significantly accelerate demulsification and dehydration, and promote oil-water separation. This method features synergistic processing, compact layout, simplified process, high efficiency, low investment, ease of operation, low operating costs, high electrification rate, and low carbon emissions.

[0041] 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

[0042] 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.

[0043] Figure 1 This is a schematic diagram of the oilfield produced fluid demulsification and dehydration device for multi-physics field coupling treatment in an embodiment of this application.

[0044] Figure 2 This is a schematic diagram showing the relationship between the electric field direction and the magnetic field direction in the electro-magnetic-acoustic integrated processing area in this embodiment of the application;

[0045] Figure 3 This refers to the steps in the embodiments of this application for multi-physics coupling processing of oilfield produced fluid.

[0046] Attached diagram descriptions: 1. Electric heating zone; 2. Magnetic treatment zone; 3. Sound treatment zone; 4. Electro-magnetic-sound integrated treatment zone. Detailed Implementation

[0047] 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.

[0048] This application provides an oilfield produced fluid demulsification and dehydration device based on multiphysics field coupling processing and its application;

[0049] Figure 1 This is a schematic diagram of the oilfield produced fluid demulsification and dehydration device used for multi-physics field coupling treatment in an embodiment of this application. Figure 1 As shown in the figure, this application provides an oilfield produced fluid demulsification and dehydration device, including: a heating zone, a magnetic treatment zone, an acoustic treatment zone, and an electro-magnetic-acoustic integrated treatment zone;

[0050] The oilfield produced fluid sequentially passes through a heating zone, a magnetic treatment zone, a acoustic treatment zone, and an electro-magnetic-acoustic integrated treatment zone.

[0051] A magnetic field exists in the magnetic processing zone, and a sound field exists in the acoustic processing zone;

[0052] The electro-magnetic-acoustic integrated processing zone contains electric, magnetic, and acoustic fields simultaneously.

[0053] When the oilfield produced fluid demulsification and dehydration device provided in this application is used to demulsify and dehydrate the oilfield produced fluid, the oilfield produced fluid is subjected to synergistic treatment by electric field, magnetic field and sound field when it flows through the electro-magnetic-acoustic integrated treatment zone.

[0054] The heating zone heats the oilfield produced fluid, which is then affected by the magnetic field in the magnetic treatment zone, the acoustic field in the acoustic treatment zone, and the electric field, magnetic field, and acoustic field that coexist in the electro-magnetic-acoustic integrated treatment zone. This causes physical or chemical changes, including but not limited to the breaking of emulsions or the stratification of immiscible fluids in the produced fluid mixture.

[0055] For example, the electric heating zone, magnetic treatment zone, acoustic treatment zone, and electro-magnetic-acoustic integrated treatment zone can be arranged in the same container or in multiple independent containers.

[0056] For example, the heating zone is electrically heated; the electric heating method includes one or both of resistance heating and electromagnetic induction heating; for example, electromagnetic induction heating is used to achieve non-contact heating.

[0057] For example, after the produced oil flows through the heating zone, the temperature of the produced oil is at least 15°C higher than the pour point of the crude oil in the produced oil.

[0058] For example, after the produced oil flows through the heating zone, the temperature of the produced oil is at least 15°C to 25°C higher than the pour point of the crude oil in the produced oil.

[0059] For example, the electric heating of the electric heating zone is either rod-type immersion electric heating or tubular flow electric heating.

[0060] In the oilfield produced fluid demulsification and dehydration device provided in this application, the sound field type of the sound treatment zone is an ultrasonic sound field;

[0061] For example, the frequency of the ultrasound is not less than 20 kHz to 100 kHz;

[0062] For example, the ultrasonic power of the ultrasonic sound field is 10 kW / m. 2 Up to 25kW / m 2 When the ultrasonic power of the ultrasonic sound field is 10 kW / m 2 Up to 25kW / m 2 At this time, cavitation of appropriate intensity can be formed, which can easily break the molecular bonds of macromolecules, and can avoid high energy consumption and serious secondary emulsification.

[0063] For example, the sound field is of the type of standing wave or traveling wave.

[0064] For example, in the oilfield produced fluid demulsification and dehydration device provided in this application, the magnetic field type of the magnetic treatment zone is a constant magnetic field; an alternating magnetic field is detrimental to the expansion and directional arrangement of macromolecules.

[0065] For example, the average magnetic induction intensity in the magnetically treated region is 1T to 2.5T, which causes the macromolecules to expand and align in a specific direction.

[0066] For example, the electric field type in the electro-magnetic-acoustic integrated processing zone is an alternating electric field; droplets undergo dipole coalescence and oscillating coalescence in the alternating electric field.

[0067] For example, the electric field frequency in the electro-magnetic-acoustic integrated processing zone is not lower than 1 kHz; if the frequency is too low, water chains connecting the electrodes are easily formed, leading to electrical breakdown.

[0068] For example, the average electric field strength in the electro-magnetic-acoustic integrated processing zone is not less than 100kV / m;

[0069] For example, the average electric field strength in the electro-magnetic-acoustic integrated processing zone is 100kV / m to 500kV / m.

[0070] For example, the magnetic field type in the electro-magnetic-acoustic integrated processing zone is an alternating magnetic field;

[0071] For example, the frequency ratio of the magnetic field frequency in the electro-magnetic-acoustic integrated processing zone to the electric field frequency in the electro-magnetic-acoustic integrated processing zone is (1 to 2):(1 to 2);

[0072] For example, the frequency ratio of the magnetic field frequency in the electro-magnetic-acoustic integrated processing zone to the electric field frequency in the electro-magnetic-acoustic integrated processing zone is 1:1;

[0073] For example, the direction of the magnetic field in the integrated electro-magnetic-acoustic processing zone is 0° to 360° from the direction of the electric field in the integrated electro-magnetic-acoustic processing zone;

[0074] For example, the direction of the magnetic field in the integrated electro-magnetic-acoustic processing zone is at 90° to the direction of the electric field in the integrated electro-magnetic-acoustic processing zone;

[0075] Figure 2 This is a schematic diagram showing the relationship between the electric and magnetic field directions in the electro-magnetic-acoustic integrated processing area in an embodiment of this application. For example, as shown... Figure 2 As shown, the direction of the magnetic field changes synchronously with the direction of the electric field and cannot be parallel to the direction of the electric field, so that the component of the Lorentz force is parallel to the direction of gravity, thereby promoting the sedimentation and separation of water droplets.

[0076] For example, the average magnetic induction intensity of the magnetic field in the electro-magnetic-acoustic integrated processing zone is not higher than 1T; if the magnetic field intensity is too high, it may cause the droplets to move circumferentially, affecting sedimentation and separation.

[0077] For example, the average magnetic induction intensity of the magnetic field in the electro-magnetic-acoustic integrated processing zone is 0.2T to 1T.

[0078] For example, the sound field type in the electro-magnetic-acoustic integrated processing zone is any one or both of standing waves and traveling waves;

[0079] For example, the type of sound field is a standing wave.

[0080] For example, the frequency ratio of the sound field frequency in the electro-magnetic-acoustic integrated processing zone to the electric field frequency in the electro-magnetic-acoustic integrated processing zone is (1 to 2):(1 to 2);

[0081] For example, the frequency ratio of the sound field frequency in the electro-magnetic-acoustic integrated processing zone to the electric field frequency in the electro-magnetic-acoustic integrated processing zone is 1:1;

[0082] For example, the standing wave vibration direction of the sound field in the electro-magnetic-acoustic integrated processing zone is 0° to 360° with the electric field direction in the electro-magnetic-acoustic integrated processing zone;

[0083] For example, the standing wave vibration direction of the sound field in the electro-magnetic-acoustic integrated processing zone is the same as the electric field direction in the electro-magnetic-acoustic integrated processing zone; this makes the oscillation direction of the droplets excited by the electric field consistent with the oscillation direction of the droplets excited by the sound wave, promoting collision and aggregation.

[0084] For example, the average sound field power in the electro-magnetic-acoustic integrated processing zone is no higher than 10 kW / m². 2 ;

[0085] For example, the average sound field power in the electro-magnetic-acoustic integrated processing zone is 2 kW / m². 2 Up to 10kW / m 2 This promotes demulsification and avoids secondary emulsification.

[0086] For example, the residence time of the oilfield produced fluid in the magnetic treatment zone is 1 min to 5 min, the residence time in the acoustic treatment zone is 2 min to 10 min, and the residence time in the electro-magnetic-acoustic integrated treatment zone is 20 min to 80 min.

[0087] This application also provides the application of the above-described device in the demulsification and dehydration of produced fluid.

[0088] Figure 3 This refers to the steps in the embodiments of this application for multi-physics coupling processing of oilfield produced fluid.

[0089] For example, the oilfield produced fluid contains any one or more of amide polymers, biopolysaccharide gums, surfactants, guar gum fracturing flowback fluid, or slickwater fracturing flowback fluid.

[0090] For example, the produced fluid has an electrical conductivity of 5 mS / cm to 20 mS / cm, an interfacial tension of 0.01 mN / m to 5 mN / m, a Zeta potential of 50 mV to 80 mV, and an average particle size of 1 μm to 15 μm.

[0091] The demulsification and dehydration method, such as Figure 3 As shown, it includes the following steps:

[0092] Step 1: Pass the raw oilfield produced fluid through the heating zone of the oilfield produced fluid demulsification and dehydration device to heat the raw oilfield produced fluid in the heating zone to obtain oilfield produced fluid A.

[0093] Step 2: The produced oil from the oilfield passes through the magnetic treatment zone of the produced oil demulsification and dehydration device. In the magnetic treatment zone, the produced oil from the oilfield A is magnetically modified to obtain produced oil from the oilfield B.

[0094] Step 3: The produced oil from the oilfield passes through the acoustic treatment zone of the produced oil demulsification and dehydration device. In the acoustic treatment zone, the produced oil from the oilfield B is subjected to ultrasonic cavitation treatment to obtain produced oil from the oilfield C.

[0095] Step 4: The produced oil from the oilfield passes through the electro-magnetic-acoustic integrated treatment zone of the produced oil demulsification and dehydration device. In the electro-magnetic-acoustic integrated treatment zone, the produced oil from the oilfield C is subjected to electro-magnetic-acoustic integrated treatment using an alternating electric field, a magnetic field, and a sound field to obtain produced oil from the oilfield D.

[0096] After multi-physics coupling processing, compared with the original oilfield produced fluid, the oilfield produced fluid D has significantly lower water content in oil and oil content in water, thus improving the oil-water separation effect.

[0097] In the process of demulsification and dehydration of produced fluids in oilfields, the produced fluids undergo heating, a first magnetic treatment, a first acoustic treatment, and a combined electro-magnetic-acoustic treatment. This specific sequence significantly enhances the effects of demulsification, dehydration, and oil-water separation. The heating process, accompanied by strong convective mass transfer, disrupts the directional arrangement of macromolecules such as polymers and surfactants. After magnetic modification, the macromolecules are more easily dispersed and their molecular bonds are broken by ultrasonic cavitation, forming smaller molecules. The interfacial film composed of these smaller molecules has lower strength and is more easily demulsified, dehydrated, and separated by the combined electro-magnetic-acoustic treatment.

[0098] In the integrated electro-magnetic-acoustic processing zone, electric, magnetic, and acoustic fields are applied simultaneously. Emulsion droplets become polarized under the electric field, leading to oscillation, collision, demulsification, and coalescence. However, droplets with low polarization can oscillate and collide under the acoustic field, simultaneously intensifying the oscillation of droplets with high polarization, enhancing the electric field treatment effect, and promoting oil-water separation. If the acoustic and electric fields are not applied simultaneously, droplets with low polarization will struggle to demulsify. Furthermore, the vibration direction of the standing wave antinodes must be parallel to the electric field direction for better results. Moving charged water droplets cutting magnetic field lines will experience Lorentz forces, accelerating the sedimentation and separation of water droplets in crude oil. Uncharged droplets cutting magnetic field lines will not experience Lorentz forces; polarization occurs under the electric field, inducing polarization charges. Therefore, the magnetic and electric fields must be applied simultaneously; and the directions of the magnetic and electric fields must not be parallel, with the frequency of the alternating magnetic field matching the frequency of the alternating electric field.

[0099] The oilfield produced fluid may contain any one or more of the following: amide polymers (e.g., polyacrylamide), biopolymer gums (e.g., xanthocyanin), surfactants (e.g., alkylbenzene sulfonates, petroleum sulfonates), guar gum fracturing flowback fluid, or slickwater fracturing flowback fluid.

[0100] The following provides a specific implementation method to illustrate the advantages of the technical solution provided in this application:

[0101] The produced fluid contains 600 mg / L of polyacrylamide and 300 mg / L of petroleum sulfonate surfactant. The crude oil has a pour point of 27°C. The produced fluid has a conductivity of 10 mS / cm, an interfacial tension of 1 mN / m, a zeta potential of 60 mV, an average particle size of 2 μm in the emulsion, and a water content of 50 wt.%.

[0102] The entire device is a cylindrical body with an inner diameter of 1.2m and a total length of 5.0m. The lengths of the electric heating zone, magnetic treatment zone, acoustic treatment zone, and electro-magnetic-acoustic integrated treatment zone are 0.5m, 0.3m, 0.4m, and 3.8m, respectively.

[0103] The injection flow rate of the oilfield produced fluid is 120 m³. 3 / d, injection temperature 30℃;

[0104] After passing through the electric heating zone, the temperature rises to 50℃;

[0105] The average magnetic induction intensity of the magnetic treatment zone was 1.1T, and the residence time was 3 minutes.

[0106] The ultrasonic wave type in the sound processing area is standing wave, with a frequency of 21000Hz and a power of 12kW / m. 2 The stay time is 5 minutes;

[0107] The dwell time in the electro-magnetic-acoustic integrated processing zone is 45 minutes.

[0108] In the integrated electro-magnetic-acoustic processing zone, the electric field frequency is 2kHz, and the average electric field strength is not less than 200kV / m.

[0109] The magnetic field type in the electro-magnetic-acoustic integrated processing zone is an alternating magnetic field. The frequency ratio of the magnetic field to the electric field frequency in the electro-magnetic-acoustic integrated processing zone is 1:1. The direction of the magnetic field is 90° to the direction of the electric field in the electro-magnetic-acoustic integrated processing zone. The average magnetic induction intensity is 0.5T.

[0110] In the electro-magnetic-acoustic integrated processing zone, the ultrasonic wave type is standing wave. The frequency ratio of the sound field to the electric field frequency in the integrated processing zone is 1:1. The magnetic field direction is the same as the electric field direction in the integrated processing zone. The average sound field power is 5 kW / m². 2 .

[0111] Conventional thermochemical treatment resulted in a crude oil water content of 15 wt.%, failing to meet the requirement of less than 0.5 wt.%, with an oil content of 600 mg / L. After treatment using the multiphysics coupling method provided in this application, the crude oil water content decreased to 0.4 wt.%, meeting the requirement of less than 0.5 wt.%, and the oil content in the water was 450 mg / L, a reduction of 150 mg / L compared to thermochemical treatment. Multiphysics coupling treatment does not consume fuel gas, and each 1 m³ of treated crude oil requires only a small amount of fuel. 3 Produced fluid consumption reduced by 1.8m 3 Fuel gas reduces carbon dioxide emissions by 3.5 kg.

[0112] This application addresses complex produced fluids by employing a novel multi-physics field coupling processing technology, which can significantly accelerate demulsification and dehydration, and promote oil-water separation. This method features synergistic processing, compact layout, simplified process, high efficiency, low investment, ease of operation, low operating costs, high electrification rate, and low carbon emissions.

[0113] The system and process are characterized by collaborative processing, compact layout, short process, high efficiency, low investment, easy operation, low operating cost, high electrification rate, and low carbon emissions.

[0114] 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. A device for demulsifying and dehydrating produced oil from an oilfield, characterized in that, include: Heating zone, magnetic treatment zone, acoustic treatment zone, and electro-magnetic-acoustic integrated treatment zone; The oilfield produced fluid contains any one or more of the following: amide polymers, biopolysaccharide gums, surfactants, guar gum fracturing flowback fluid, and slickwater fracturing flowback fluid. The heating zone, the magnetic treatment zone, the acoustic treatment zone, and the electro-magnetic-acoustic integrated treatment zone are connected in sequence; The electro-magnetic-acoustic integrated processing area is configured to provide electric, magnetic, and acoustic fields; The magnetic field provided by the magnetic processing zone is a constant magnetic field. The sound field type of the sound processing area is an ultrasonic sound field. The type of magnetic field provided by the electro-magnetic-acoustic integrated processing zone is an alternating magnetic field; The electric field provided by the electro-magnetic-acoustic integrated processing zone is an alternating electric field. In the electro-magnetic-acoustic integrated processing zone, electric field, magnetic field, and acoustic field processing are carried out simultaneously; the direction of the magnetic field changes synchronously with the direction of the electric field and cannot be parallel to the direction of the electric field, so that the component of the Lorentz force on the extracted liquid droplets is parallel to the direction of gravity; the emulsion droplets are polarized under the electric field, and droplets with low polarization can oscillate and collide under the action of the acoustic field. The ratio of the frequency of the magnetic field provided by the integrated electro-magnetic-acoustic processing zone to the frequency of the electric field provided by the integrated electro-magnetic-acoustic processing zone is 1:1; The ratio of the frequency of the sound field provided by the electro-magnetic-acoustic integrated processing zone to the frequency of the electric field provided by the electro-magnetic-acoustic integrated processing zone is 1:1; The frequency of the electric field provided by the electro-magnetic-acoustic integrated processing zone is not less than 1 kHz.

2. The oilfield produced fluid demulsification and dehydration device according to claim 1, characterized in that, The heating zone is electrically heated; the electric heating method includes any one or both of resistance heating and electromagnetic induction heating.

3. The oilfield produced fluid demulsification and dehydration device according to claim 1 or 2, characterized in that, The sound field provided by the sound processing area is of the type of standing wave or traveling wave.

4. The oilfield produced fluid demulsification and dehydration device according to any one of claims 1 to 2, characterized in that, The type of sound field provided by the electro-magnetic-acoustic integrated processing zone is any one or both of standing waves and traveling waves.

5. A method for demulsification and dehydration, characterized in that, Using the oilfield produced fluid demulsification and dehydration device according to any one of claims 1 to 4 to demulsify and dehydrate oilfield produced fluid includes: passing the oilfield produced fluid sequentially through the heating zone, the magnetic treatment zone, the acoustic treatment zone, and the electro-magnetic-acoustic integrated treatment zone of the oilfield produced fluid demulsification and dehydration device.

6. The demulsification and dehydration method according to claim 5, characterized in that, After the produced fluid from the oilfield flows through the heating zone, the temperature of the produced fluid is more than 15°C higher than the pour point of the crude oil in the produced fluid.

7. The demulsification and dehydration method according to claim 6, characterized in that, After the produced fluid from the oilfield flows through the heating zone, the temperature of the produced fluid is 15°C to 25°C higher than the pour point of the crude oil in the produced fluid.

8. The demulsification and dehydration method according to claim 5, characterized in that, The sound processing area provides a sound field frequency of 20kHz to 100kHz. The acoustic processing area provides a sound field power of 10kW / m². 2 Up to 25kW / m 2 ; The magnetic field provided by the magnetic processing zone has an average magnetic induction intensity of 1T to 2.5T; The average electric field strength provided by the electro-magnetic-acoustic integrated processing zone is not less than 100kV / m; The average magnetic induction intensity of the magnetic field provided by the electro-magnetic-acoustic integrated processing zone is no higher than 1T; The direction of the standing wave vibration of the sound field provided by the electro-magnetic-acoustic integrated processing zone forms an angle of 0° to 360° with the direction of the electric field provided by the electro-magnetic-acoustic integrated processing zone. The average sound field power provided by the electro-magnetic-acoustic integrated processing zone is no higher than 10kW / m². 2 .

9. The demulsification and dehydration method according to claim 8, characterized in that, The average electric field strength provided by the electro-magnetic-acoustic integrated processing zone is 100kV / m to 500kV / m; The direction of the magnetic field provided by the integrated electro-magnetic-acoustic processing zone is 90° to the direction of the electric field provided by the integrated electro-magnetic-acoustic processing zone; The average magnetic induction intensity of the magnetic field provided by the electro-magnetic-acoustic integrated processing zone is 0.2T to 1T; The direction of the standing wave vibration of the sound field provided by the electro-magnetic-acoustic integrated processing zone is the same as the direction of the electric field provided by the electro-magnetic-acoustic integrated processing zone; The average sound field power provided by the electro-magnetic-acoustic integrated processing zone is 2kW / m². 2 Up to 10kW / m 2 .

10. The demulsification and dehydration method according to any one of claims 5 to 9, characterized in that, The residence time of the oilfield produced fluid in the magnetic treatment zone is 1 to 5 minutes, in the acoustic treatment zone is 2 to 10 minutes, and in the electro-magnetic-acoustic integrated treatment zone is 20 to 80 minutes.

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