Efficient dehydration treatment device and method based on layered pre-dehydration and multi-field coupling demulsification coalescence

Abstract

The invention belongs to the technical field of crude oil dehydration and sump oil dehydration, and particularly relates to an efficient dehydration treatment device and method based on layering pre-dehydration and multi-field coupling demulsification coalescence. In the dehydration treatment device, a layering pre-dehydrator is provided with a first inlet, a first oil phase outlet, an emulsion outlet and a first water phase outlet; the multi-field coupling demulsification coalescence dehydrator is provided with a second inlet, a second oil phase outlet and a second water phase outlet; the cyclone dehydrator comprises a third inlet, a light phase outlet and a third water phase outlet; the first oil phase outlet and the second oil phase outlet are both connected with the oil storage tank; the emulsion outlet and the light phase outlet are both connected with the second inlet, and a demulsifier adder is arranged on a connecting pipeline; the first water phase outlet and the second water phase outlet are both connected with the third inlet, and the third water phase outlet is connected with the sewage storage tank. The device has the advantages of being high in structural compactness, small in occupied space, convenient to transport, install and maintain and high in dehydration efficiency.

Description

Technical Field

[0001] The invention belongs to the technical field of crude oil dehydration and waste oil dehydration, and particularly relates to a high-efficiency dehydration treatment device and method based on stratified pre-dehydration and multi-field coupled demulsification and coalescence. Background Art

[0002] Crude oil dehydration is one of the important and indispensable links in the oil production process. As oilfield development gradually enters the middle and late stages, the water content and mud and sand content of oilfield produced fluid are high, the physical properties of produced fluid are becoming more complex, and its emulsification problem is serious. The emulsion has a complex morphology and strong stability, making it difficult to separate oil and water. At present, there are mainly physical and chemical methods for crude oil treatment. The physical method is based on chemical-assisted demulsification, and provides external force and energy to the emulsion through electric field, magnetic field, acoustic field, membrane separation, centrifugation, etc., so that the interfacial membrane of the dispersed phase droplets is destroyed and re-aggregated into larger droplets, and then promotes their separation under the action of external force. In fact, the method that is widely used in crude oil dehydration technology is the electro-dehydration method. Electro-dehydration is that under the action of an electric field, due to the difference in electrical conductivity between the oil and water phases, the water droplets in the water-containing crude oil are polarized, and a dipole cohesion force that attracts the water droplets to each other is generated between the polarized water droplets. The electric field force will stretch and deform the polarized water droplets, and the deformation of the water droplets will weaken the strength of the interfacial film between the water droplets, thereby promoting the aggregation of the water droplets. After the water droplets aggregate, the particle size increases, and they settle and separate under the action of gravity.

[0003] In the related art, the main body of the electrode plate group in the crude oil electric dehydration equipment is generally a metal plate made of metal. During dehydration, it is immersed in the emulsified crude oil and in direct contact with the emulsified crude oil. However, it is found in the actual production process that due to the strong conductivity of the emulsified crude oil with a high water content, when high voltage is applied to the metal plate, it will cause the increase of leakage current between the positive metal plate and the negative metal plate, causing a short circuit. Therefore, there is a considerable safety hazard. At the same time, scaling is easily generated on the insulating plate, which will destroy the electric field formed between the metal plates, resulting in the inability of water droplets in the emulsified crude oil to effectively coalesce, affecting the final oil-water separation effect.

[0004] As the crude oil dehydration technology has more and more problems and the demand is becoming increasingly severe, technicians in related fields have proposed to improve the existing emulsion electric dehydration technology by changing the electrode layout and the power supply form of the dehydration power supply. For example, according to the different waveforms of the power supply voltage, electric dehydration can be divided into DC electric field dehydration, AC electric field dehydration, AC-current dual electric field dehydration, and high-frequency pulse electric field dehydration. In the AC and high-frequency pulse electric fields, the water droplets in the emulsion undergo dipole aggregation and oscillation aggregation. In the DC electric field, in addition to dipole aggregation, the water droplets in the emulsion mainly aggregate by electrophoresis. In the AC-DC dual electric field, the above-mentioned forms of aggregation exist. In recent years, the gradual application of high-frequency / high-voltage pulse electric field dehydration technology in electric dehydrators has effectively solved the problems existing in its treatment of high-water-content crude oil, and can reduce the use of demulsifiers. For example, patent CN 112779048 A proposed a high-frequency pulse electrostatic-ultrasonic combined coalescence demulsification electric dehydrator, which can effectively improve the dehydration efficiency of crude oil and avoid problems such as short circuit between electrode plates. However, since conventional electric dehydrators still use gravity sedimentation, they still have shortcomings such as large equipment footprint and low dehydration efficiency. Dehydration equipment based on centrifugal separation technology, represented by hydrocyclones, is widely used because of its high separation efficiency and compact structure. Combining electric field demulsification with oil-water centrifugal separation can greatly simplify the traditional electric dehydration process and improve dehydration efficiency. For example, patent CN 111704926B proposed an anti-scaling thermoelectric coalescence dehydrator coupled with a collector field-ultrasonic field-centrifugal field, which combines electric dehydration technology, ultrasonic demulsification dehydration technology, cyclone separation dehydration technology and thermal treatment dehydration technology to improve demulsification efficiency. However, the current equipment has poor controllability and the overall efficiency is still low. This means that a more advanced technical means is needed to achieve efficient and high-precision demulsification and achieve the processing goals of intelligence, refinement and integration.

[0005] Therefore, in view of the above shortcomings, the present invention is specially proposed. Summary of the invention

[0006] The object of the present invention is to provide a high-efficiency dehydration treatment device and method based on stratified pre-dehydration and multi-field coupled emulsion breaking and coalescence, so as to at least partially solve the above technical problems.

[0007] The first aspect of the present invention provides a high-efficiency dehydration treatment device based on stratified pre-dehydration and multi-field coupled demulsification and coalescence, comprising a stratified pre-dehydrator, a cyclone dehydrator, a multi-field coupled demulsification and coalescence dehydrator, a demulsifier adder, an oil-water ratio analyzer, an oil storage tank, and a sewage storage tank. The stratified pre-dehydrator is provided with a first inlet, a first oil phase outlet, an emulsion outlet, and a first water phase outlet. The multi-field coupled demulsification and coalescence dehydrator is provided with a second inlet, a second oil phase outlet, and a second water phase outlet. The cyclone dehydrator includes a third inlet, a light phase outlet, and a third water phase outlet; wherein

[0008] The first oil phase outlet and the second oil phase outlet are both connected to the oil storage tank, and the oil-water ratio analyzer is provided on the connecting pipeline; the emulsion outlet and the light phase outlet are both connected to the second inlet, and the demulsifier adder is provided on the connecting pipeline; the first water phase outlet and the second water phase outlet are both connected to the third inlet, and the third water phase outlet is connected to the sewage storage tank.

[0009] The high-efficiency dehydration treatment device based on layered pre-dehydration and multi-field coupled demulsification and coalescence provided by the present invention may also have the following additional technical features:

[0010] In a specific embodiment of the present invention, the multi-field coupled demulsification coalescence dehydrator comprises:

[0011] a housing having the second inlet, the second oil phase outlet and the second water phase outlet;

[0012] A centrifugal separation assembly, comprising a centrifugal separation impeller, a variable frequency motor, a conductive slip ring and a grounding electrode, wherein the centrifugal separation impeller is arranged in the housing and comprises a rotating electrode shaft and blades arranged on the periphery of the rotating electrode shaft, the variable frequency motor is connected to the rotating electrode shaft, the conductive slip ring is sleeved on the rotating electrode shaft and connected to the grounding electrode;

[0013] A pulse assembly, comprising an annular electrode plate and a pulse power supply, wherein the annular electrode plate is disposed in the housing and electrically connected to the pulse power supply;

[0014] The ultrasonic component comprises an ultrasonic transducer and an ultrasonic generator. The ultrasonic transducer is arranged in the shell and is electrically connected to the ultrasonic generator.

[0015] In a specific implementation manner of the present invention, the output end of the variable frequency motor is connected to the rotating electrode shaft via a transition coupling and an insulating connector.

[0016] In a specific embodiment of the present invention, the surface of the annular electrode plate is coated with an insulating material; and / or

[0017] The inner wall surface of the housing is provided with a hydrophobic insulating layer; and / or

[0018] The number of the blades is 6-12; and / or

[0019] The speed of the variable frequency motor is 0-6000r / min.

[0020] In a specific embodiment of the present invention, the housing includes a cylindrical main body for accommodating the centrifugal separation impeller, the annular electrode plate and the ultrasonic transducer, and the ratio of the inner diameter of the ultrasonic transducer to the diameter of the main body is 1 / 3-2 / 3.

[0021] In a specific embodiment of the present invention, the stratified pre-dehydrator pre-separates the crude oil entering from the first inlet into a water layer, an emulsion layer and an oil layer based on gravity and / or electric field.

[0022] In a specific embodiment of the present invention, the number of the stratified pre-dehydrators is two, and the two stratified pre-dehydrators are arranged in parallel; and / or

[0023] There are two cyclone dehydrators, the third inlet of one cyclone dehydrator is connected to the first water phase outlet, and the third inlet of another cyclone dehydrator is connected to the second water phase outlet.

[0024] The second aspect of the present invention further provides a dehydration method, which is implemented by using any one of the dehydration devices described above, and comprises the following steps:

[0025] The stratified pre-dehydrator is used to pre-separate the crude oil transported from the first inlet into a water layer, an emulsion layer and an oil layer, and the separated oil, emulsion and water are transported to the oil storage tank, the multi-field coupled demulsification coalescence dehydrator and the cyclone dehydrator through the first oil phase outlet, the emulsion outlet and the first water phase outlet respectively;

[0026] The demulsifier is added to the emulsion and / or light phase transported to the multi-field coupled demulsification coalescing dehydrator by using the demulsifier adder;

[0027] The multi-field coupled demulsification coalescence dehydrator is used to separate the emulsion and / or light phase into a water phase and an oil phase, and the separated oil phase and water phase are transported to an oil storage tank and a cyclone dehydrator through a second oil phase outlet and a second water phase outlet, respectively;

[0028] A cyclone dehydrator is used to separate the water phase transported from the third inlet into a light phase and a water phase, and the separated light phase and water phase are transported to a multi-field coupled demulsification coalescence dehydrator and a sewage storage tank through a light phase outlet and a third water phase outlet, respectively.

[0029] In a specific embodiment of the present invention, the multi-field coupled demulsification coalescing dehydrator separates the emulsion and / or light phase into a water phase and an oil phase based on the synergistic effect of an electric field, a centrifugal separation field and ultrasound.

[0030] In a specific embodiment of the present invention, the oil-water ratio of the oil phase delivered to the oil storage tank is detected by an oil-water ratio analyzer, and the oil phase with a standard oil-water ratio is delivered to the oil storage tank.

[0031] The high-efficiency dehydration treatment device provided by the present invention can separate the produced crude oil into a water layer, an emulsion layer and an oil layer by setting a stratified pre-dehydrator, and then treat the stratified crude oil separately. For the emulsion that is most difficult to treat, a multi-field coupled demulsification and coalescence dehydrator is used. The invention can be used to carry out targeted treatment according to the characteristics of the treated liquid, that is, to achieve more efficient treatment of crude oil according to local conditions, and greatly reduce the amount of demulsifier and reduce costs.

[0032] The multi-field coupled demulsification and coalescence dehydrator in the dehydration treatment device provided by the present invention effectively combines the advantages of electric field, centrifugal field and ultrasonic treatment of emulsion, gives full play to the advantages of each treatment technology, achieves the goal of efficient and accurate dehydration, and avoids problems such as electrode short circuit breakdown and scaling leading to poor dehydration effect, thereby realizing precise and efficient treatment by taking advantage of strengths and avoiding weaknesses.

[0033] In the dehydration treatment device provided by the present invention, the stratified pre-dehydrator, the multi-field coupled emulsification and coalescence dehydrator, and the cyclone dehydrator are effectively coordinated. The whole device has a high compact structure, occupies a small space, is easy to transport, install and maintain, and has a high dehydration efficiency, achieving the goals of precision and efficiency, closed process, and integrated device. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] In order to more clearly illustrate the specific implementation methods of the present invention or the technical solutions in the prior art, the drawings required for use in the specific implementation methods or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are some implementation methods of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0035] Figure 1 A schematic diagram of the structure of a dehydration treatment device in one embodiment of the present invention;

[0036] Figure 2 for Figure 1 Schematic diagram of the structure of the medium multi-field coupled demulsification coalescence dehydrator.

[0037] Description of reference numerals:

[0038] 100-dehydration treatment device;

[0039] 1-Oil well produced liquid inlet pipeline; 2-Separation pre-dehydrator; 3-Oil phase delivery pipeline; 4-Emulsion delivery pipeline; 5-Water phase delivery pipeline; 6-1# Cyclone dehydrator; 7-Demulsifier adder; 8-Multi-field coupling demulsification coalescence dehydrator; 9-Oil-water ratio analyzer; 11-Oil storage tank; 12-Transition high water content oil storage tank; 13-2# Cyclone dehydrator; 14-Sewage storage tank; 15-Sewage discharge pipeline; 80 1- variable frequency motor; 802- transition coupling; 803- insulating connector; 804- conductive slip ring; 805- rotating electrode shaft; 806- grounding electrode; 807- second oil phase outlet; 808- centrifugal separation impeller; 809- annular electrode plate; 810- pulse power supply; 811- ultrasonic transducer; 812- ultrasonic generator; 813- housing; 814- second inlet; 815- second water phase outlet. DETAILED DESCRIPTION

[0040] The exemplary embodiments of the present invention will be described in more detail below with reference to the accompanying drawings. Although the exemplary embodiments of the present invention are shown in the accompanying drawings, it should be understood that the present invention can be implemented in various forms and should not be limited by the embodiments described herein. On the contrary, these embodiments are provided in order to enable a more thorough understanding of the present invention and to fully convey the scope of the present invention to those skilled in the art.

[0041] It should be understood that the terms used herein are only for the purpose of describing specific example embodiments and are not intended to be limiting. Unless the context clearly indicates otherwise, the singular forms "one", "an" and "said" as used herein may also be meant to include plural forms. The terms "include", "comprise", "contain", and "have" are inclusive, and therefore specify the existence of stated features, steps, operations, elements and / or parts, but do not exclude the existence or addition of one or more other features, steps, operations, elements, parts, and / or combinations thereof. The method steps, processes, and operations described herein are not interpreted as necessarily requiring them to be performed in the specific order described or illustrated, unless the execution order is clearly indicated. It should also be understood that additional or alternative steps may be used.

[0042] Although the terms first, second, third, etc. can be used in the text to describe multiple elements, components, regions, layers and / or sections, these elements, components, regions, layers and / or sections should not be limited by these terms. These terms can only be used to distinguish an element, component, region, layer or section from another region, layer or section. Unless the context clearly indicates, terms such as "first", "second" and other numerical terms do not imply order or sequence when used in the text. Therefore, the first element, component, region, layer or section discussed below can be referred to as the second element, component, region, layer or section without departing from the teaching of the example embodiments.

[0043] For ease of description, spatial relative terms may be used herein to describe the relationship of one element or feature relative to another element or feature as shown in the figure, such as "inside", "outside", "inner side", "outer side", "below", "below", "above", "above", etc. Such spatial relative terms are intended to include different orientations of the device in use or operation in addition to the orientation depicted in the figure. For example, if the device in the figure is turned over, then the elements described as "below other elements or features" or "below other elements or features" will subsequently be oriented as "above other elements or features" or "above other elements or features". Therefore, the example term "below..." can include both upper and lower orientations. The device can be oriented otherwise (rotated 90 degrees or in other directions) and the spatial relative descriptors used in the text are interpreted accordingly.

[0044] Reference Figure 1-2 In a first aspect, the present invention provides a high-efficiency dehydration treatment device 100 based on stratified pre-dehydration and multi-field coupled demulsification and coalescence, comprising a stratified pre-dehydrator 2, a cyclone dehydrator, a multi-field coupled demulsification and coalescence dehydrator 8, a demulsifier adder 7, an oil-water ratio analyzer 9, an oil storage tank 11, and a sewage storage tank 14. The stratified pre-dehydrator 2 is provided with a first inlet, a first oil phase outlet, an emulsion outlet and a first water phase outlet, and the multi-field coupled demulsification and coalescence dehydrator 8 is provided with a second inlet 814, a second oil phase outlet 807 and the second water phase outlet 815, the cyclone dehydrator includes a third inlet, a light phase outlet and a third water phase outlet; wherein the first oil phase outlet and the second oil phase outlet 807 are both connected to the oil storage tank 11, and an oil-water ratio analyzer 9 is provided on the connecting pipeline; the emulsion outlet and the light phase outlet are both connected to the second inlet 814, and a demulsifier additive 7 is provided on the connecting pipeline; the first water phase outlet and the second water phase outlet 815 are both connected to the third inlet, and the third water phase outlet is connected to the sewage storage tank 14.

[0045] Specifically, the stratified pre-dehydrator 2, the cyclone dehydrator, the multi-field coupled demulsification and coalescence dehydrator 8, and the oil storage tank 11 are all connected through a delivery pipeline with a valve. For example, the first inlet is connected to the oil well produced liquid inlet pipeline 1, the first water phase outlet is connected to the third inlet of the cyclone dehydrator through the water phase delivery pipeline 5, the first oil phase outlet is connected to the oil storage tank 11 through the oil phase output pipeline, and the emulsion outlet is connected to the second inlet 814 of the multi-field coupled demulsification and coalescence dehydrator 8 through the emulsion delivery pipeline 4. Among them, in order to ensure the continuity of transportation, a transfer pump is provided on the transportation pipeline connected to the third inlet of the cyclone dehydrator, the second inlet 814 of the multi-field coupled demulsification and coalescence dehydrator 8 and the inlet of the oil storage tank; at the same time, in order to simplify the transportation pipeline, the transportation pipeline between the emulsion outlet and the light phase outlet and the second inlet 814 is merged upstream of the transmission pump, and the demulsifier adder 7 is arranged downstream of the transmission pump, so that it can be used to add demulsifier to the emulsion and light phase transmitted to the multi-field coupled demulsification and coalescence dehydrator 8. There are two oil-water ratio analyzers 9, one of which is arranged on the transmission pipeline between the first oil phase outlet and the oil storage tank 11, and is used to obtain in real time whether the oil-water ratio in the oil phase at the first oil phase outlet reaches a preset value, and allows it to be transported to the oil storage tank 11 through the transmission pipeline when it reaches the preset value; the other is arranged between the second oil phase outlet 807 and the oil storage tank 11, and is used to obtain in real time whether the oil-water ratio in the oil phase at the second oil phase outlet 807 reaches a preset value, and allows it to be transported to the oil storage tank 11 through the transmission pipeline when it reaches the preset value.

[0046] During operation, crude oil enters the stratified pre-dehydrator 2 through the first inlet, and is separated from bottom to top into a water layer, an emulsion layer and an oil layer after being processed by the stratification and dehydrator. The oil phase in the oil layer enters the transmission pipeline through the first oil phase outlet, and is transported to the oil storage tank 11 for storage after being tested and qualified by the oil-water ratio analyzer 9. The emulsion in the emulsion layer enters the transmission pipeline through the emulsion outlet, and enters the multi-field coupled demulsification coalescence dehydrator 8 for further treatment after the demulsifier is added by the demulsifier adder 7. The water phase in the water layer enters the transmission pipeline through the first water phase outlet, and is transported to the cyclone dehydrator for further treatment. Similarly, the oil phase obtained by the multi-field coupled demulsification coalescence dehydrator 8 is transported to the oil storage tank 11 for storage after being tested and qualified by the oil-water ratio analyzer 9, and the water phase obtained by the multi-field coupled demulsification coalescence dehydrator 8 is transported to the cyclone dehydrator for further treatment. The water phase conveyed to the cyclone dehydrator via the stratified pre-dehydrator 2 and the multi-field coupled demulsification and coalescence dehydrator 8 is further treated by the cyclone dehydrator, and the light phase obtained thereafter is conveyed to the multi-field coupled demulsification and coalescence dehydrator 8 for further treatment, and the obtained water tank is conveyed to the sewage storage tank 14.

[0047] The dehydration treatment device 100 provided by the present invention can divide the produced crude oil into a water layer, an emulsion layer, and an oil layer by setting a stratified pre-dehydrator 2, and then treat the stratified crude oil separately. For the emulsion that is most difficult to treat, a multi-field coupled demulsification and coalescence dehydrator 8 is used. The invention can be used to treat the treated liquid in a targeted manner according to the characteristics of the treated liquid, that is, to achieve more efficient treatment of crude oil according to local conditions, and greatly reduce the amount of demulsifier and reduce costs. At the same time, in the above-mentioned dehydration treatment device 100, by making the stratified pre-dehydrator 2, the multi-field coupled demulsification and coalescence dehydrator 8, and the cyclone dehydrator effectively cooperate, the whole set of equipment has a high compact structure, small footprint, convenient transportation, installation and maintenance, and high dehydration efficiency, achieving the goals of precision and efficiency, closed process, and integrated equipment.

[0048] In one embodiment, the multi-field coupling demulsification coalescence dehydrator 8 includes a housing 813, a centrifugal separation component, a pulse component and an ultrasonic component, wherein the housing 813 is provided with a second inlet 814, a second oil phase outlet 807 and a second water phase outlet 815; the centrifugal separation component includes a centrifugal separation impeller 808, a variable frequency motor 801, a conductive slip ring 804 and a grounding electrode 806, the centrifugal separation impeller 808 is arranged in the housing 813, and includes a rotating electrode shaft 805 and a rotating electrode shaft 805 arranged outside the rotating electrode shaft 805. The variable frequency motor 801 is connected to the rotating electrode shaft 805, the conductive slip ring 804 is sleeved on the rotating electrode shaft 805, and is connected to the grounding electrode 806; the pulse component includes an annular electrode plate 809 and a pulse power supply 810, the annular electrode plate 809 is arranged in the shell 813, and is electrically connected to the pulse power supply 810; the ultrasonic component includes an ultrasonic transducer 811 and an ultrasonic generator 812, the ultrasonic transducer 811 is arranged in the shell 813, and is electrically connected to the ultrasonic generator 812.

[0049] The shell is formed as a cylindrical structure with a receiving cavity, wherein the second inlet 814 and the second water phase outlet 815 are both located at the bottom, and the second oil phase outlet 807 is located at the top.

[0050] The centrifugal impeller 808 in the centrifugal separation assembly is arranged in the housing 813, and its rotating electrode shaft 805 is connected to the variable frequency motor 801 arranged above the housing 813, and is suitable for traveling the centrifugal separation field under the drive of the variable frequency motor 801. At the same time, the rotating electrode shaft 805 is also connected to the grounding electrode 806 by sleeved with its outer conductive slip ring 804, so that it can be adapted to the annular electrode plate 809 located in the housing 813, and then can form an electric field under the action of the high-voltage pulse power supply 810 provided by the pulse power supply 810. The ultrasonic transducer 811 is arranged in the housing 813, and is specifically located below the centrifugal impeller 808, which can form ultrasonic waves under the action of the ultrasonic generator 812.

[0051] Based on the above structure, the multi-field coupled demulsification coalescence dehydrator 8 is formed as a dehydrator coupled with an electric field, a centrifugal separation field and an ultrasonic wave. The emulsion and the light phase added with demulsifier entering through the second inlet 814 are subjected to the synergistic action of the electric field, the centrifugal separation field and the ultrasonic wave. The water phase droplets continuously vibrate, collide, the interface film breaks, and coalesce. The water droplets approach each other and combine together, and the particle size of the droplets increases. Under the action of the strong centrifugal force, the oil and water phases are gradually separated into an inner and outer layer. The water phase is thrown to the inner wall of the outer shell 813, while the relatively light oil phase gathers in the center. As the emulsion is continuously introduced, the water phase thrown to the outer wall of the dehydration device moves downward under the action of gravity and flows out through the second water phase outlet 815. At the same time, the relatively light oil phase gathers in the center and continuously rises to the second oil phase outlet 807 for discharge, thereby completing the oil-water separation of the emulsion. Moreover, since the second inlet 814 can continuously input the emulsion and the light phase, the above treatment process is dynamic and continuous.

[0052] In one embodiment, the output end of the variable frequency motor 801 is connected to the rotating electrode shaft 805 through a transition coupling 802 and an insulating connector 803. In this way, the insulated transmission connection between the variable frequency motor 801 and the centrifugal separation impeller 808 can be achieved, thereby reducing the interference of the electric field in the housing 813 on the variable frequency motor 801 and ensuring the function of the centrifugal separation assembly.

[0053] In one embodiment, the surface of the annular electrode plate 809 is coated with an insulating material. Specifically, the insulating material may be polytetrafluoroethylene, Teflon and / or epoxy resin.

[0054] In one embodiment, the inner wall surface of the housing 813 is provided with a hydrophobic insulating layer, which can improve its hydrophobicity and the ability to collect water droplets.

[0055] In one embodiment, the number of the blades is 6 to 12. Optionally, the number of the blades is 6, 8, 10 or 12.

[0056] In one embodiment, the speed of the variable frequency motor 801 is 0-6000 r / min. For example, the speed of the variable frequency motor 801 is 100 r / min, 200 r / min, 500 r / min, 800 r / min, 1000 r / min, 1500 r / min, 2000 r / min, 3000 r / min, 4000 r / min, 5000 r / min, 6000 r / min, etc., any value between 0-6000 r / min. Through the above setting, the centrifugal force of the centrifugal separation impeller 808 can be easily adjusted.

[0057] In one embodiment, the voltage range provided by the pulse power supply 810 is 0-30 kV, and the frequency adjustment range is 200 Hz-20 kHz. For example, the pulse voltage is 100 V, 200 V, 500 V, 800 V, 1 KV, 2 kV, 5 kV, 8 kV, 10 kV, 15 kV, 20 kV, 25 kV or 30 kV, and the frequency is 200 Hz, 500 Hz, 800 Hz, 1 kHz, 2 kHz, 5 kHz, 8 kHz, 10 kHz, 15 kHz or 20 kHz.

[0058] In one embodiment, the operating frequency of the ultrasonic wave is 0-50 KHz. For example, the operating frequency of the ultrasonic wave is 0.1 KHz, 0.5 KHz, 1 KHz, 2 KHz, 5 KHz, 10 KHz, 15 KHz, 20 KHz.

[0059] In one embodiment, the housing 813 includes a cylindrical main body for accommodating the centrifugal separation impeller 808, the annular electrode plate 809 and the ultrasonic transducer 811, and the ratio of the inner diameter of the ultrasonic transducer 811 to the diameter of the main body is 1 / 3-2 / 3.

[0060] Specifically, the upper part of the main body is formed into a cylindrical shape, and the lower part thereof is formed into a closed truncated cone shape. The housing 813 also includes an upper cover and a lower connecting portion, wherein the upper cover includes a cover plate adapted to the upper end of the main body, a cylinder plugged into the center of the cover plate, and a branch connected to the side wall of the cylinder, wherein the cover plate is sealed and connected to the upper end of the main body, the cylinder is connected to the inner cavity of the main body, and the branch forms a second oil phase outlet 807. Lower connecting portion The lower connecting portion includes a first tube body and a second tube body, wherein the first end of the first tube body is located at the center of the first end of the second tube body, and the other end is located outside the second tube body and forms a second inlet 814, the first section of the second tube body is connected to the truncated cone end of the main body, and the second end forms a second water phase outlet 815.

[0061] The ultrasonic transducer 811 is in a circular ring shape and is disposed in the cylindrical structure of the main body, and the inner diameter is 1 / 3-2 / 3 of the diameter of the main body, which can increase its radiation area and improve the treatment effect on the emulsion and the light phase.

[0062] In one embodiment, the stratified pre-dehydrator 2 pre-separates the crude oil entering from the first inlet into a water layer, an emulsion layer and an oil layer based on gravity and / or electric field.

[0063] In one embodiment, the number of the stratified pre-dehydrators 2 is two, and the two stratified pre-dehydrators 2 are arranged in parallel, so as to improve the pretreatment efficiency of crude oil.

[0064] Specifically, the two stratification pre-dehydrators 2 can work simultaneously, or one stratification pre-dehydrator 2 completes pre-stratification and opens the first oil phase outlet, the emulsion outlet and the first water phase outlet to start the output of the oil phase, the water phase and the emulsion, and the first oil phase outlet, the emulsion outlet and the first water phase outlet of the other stratification pre-dehydrator 2 are closed and the pre-stratification process is started.

[0065] In one embodiment, there are two cyclone dehydrators, namely 1# cyclone dehydrator 6 and 2# cyclone dehydrator 13 , wherein the third inlet of 1# cyclone dehydrator 6 is connected to the first water phase outlet, and the third inlet of 2# cyclone dehydrator 13 is connected to the second water phase outlet 815 .

[0066] Specifically, the 1# cyclone dehydrator 6 is used to process the water phase pre-separated by the stratified pre-dehydrator 2 , and the 2# cyclone dehydrator 13 is used to process the water phase separated by the multi-field coupled demulsification coalescence dehydrator 8 .

[0067] Optionally, a transition high-water oil storage tank 12 is further provided between the multi-field coupled demulsification coalescence dehydrator 8 and the 2# cyclone dehydrator 13, so that the flow between the multi-field coupled demulsification coalescence dehydrator 8 and the 2# cyclone dehydrator 13 can be controlled.

[0068] The 1# cyclone dehydrator 6 and the 2# cyclone dehydrator 13 are both connected to the sewage storage tank 14 through the sewage discharge pipeline 15 .

[0069] It should be noted that the water phase, oil phase, emulsion and light phase in the treatment products of the stratified pre-dehydrator 2, the multi-field coupled demulsification and coalescence dehydrator 8 and the cyclone dehydrator in this embodiment are all oil-water mixtures, wherein the water content in the water phase is higher than the preset value, the oil content in the oil phase is higher than the preset value, and the oil content in the emulsion and the light phase is within the preset range.

[0070] The second aspect of the present invention further provides a dehydration method, which is implemented by using any one of the above dehydration devices 100, and comprises the following steps:

[0071] The crude oil delivered from the first inlet is pre-divided into a water layer, an emulsion layer and an oil layer by using a stratified pre-dehydrator 2, and the separated oil, emulsion and water are respectively delivered to an oil storage tank 11, a multi-field coupled demulsification coalescence dehydrator 8 and a cyclone dehydrator through a first oil phase outlet, an emulsion outlet and a first water phase outlet;

[0072] A demulsifier is added to the emulsion and / or light phase transported to the multi-field coupled demulsification coalescence dehydrator 8 by using a demulsifier adder 7;

[0073] The multi-field coupled demulsification coalescence dehydrator 8 is used to separate the emulsion and / or light phase into a water phase and an oil phase, and the separated oil phase and water phase are transported to the oil storage tank 11 and the cyclone dehydrator through the second oil phase outlet 807 and the second water phase outlet 815 respectively;

[0074] A cyclone dehydrator is used to separate the water phase transported from the third inlet into a light phase and a water phase, and the separated light phase and water phase are transported to the multi-field coupled demulsification coalescence dehydrator 8 and the sewage storage tank 14 through the light phase outlet and the third water phase outlet respectively.

[0075] In a specific embodiment of the present invention, the multi-field coupled demulsification coalescence dehydrator 8 separates the emulsion and / or light phase into a water phase and an oil phase based on the synergistic effect of an electric field, a centrifugal separation field and ultrasound.

[0076] In a specific embodiment of the present invention, the oil-water ratio of the oil phase delivered to the oil storage tank 11 is detected by an oil-water ratio analyzer 9, and the oil phase with a standard oil-water ratio is delivered to the oil storage tank 11.

[0077] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or replace some or all of the technical features therein with equivalents. However, these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. An efficient dehydration treatment device based on layered pre-dehydration and multi-field coupled demulsification and coalescence, characterized in that: It includes a stratified pre-dehydrator, a cyclone dehydrator, a multi-field coupled demulsification coalescence dehydrator, a demulsifier adder, an oil-water ratio analyzer, an oil storage tank, and a sewage storage tank. The stratified pre-dehydrator is provided with a first inlet, a first oil phase outlet, an emulsion outlet, and a first water phase outlet. The multi-field coupled demulsification coalescence dehydrator is provided with a second inlet, a second oil phase outlet, and a second water phase outlet. The cyclone dehydrator includes a third inlet, a light phase outlet, and a third water phase outlet. The first oil phase outlet and the second oil phase outlet are both connected to the oil storage tank, and the oil-water ratio analyzer is provided on the connecting pipeline; the emulsion outlet and the light phase outlet are both connected to the second inlet, and the demulsifier adder is provided on the connecting pipeline; the first water phase outlet and the second water phase outlet are both connected to the third inlet, and the third water phase outlet is connected to the sewage storage tank.

2. The high-efficiency dehydration treatment device based on layered pre-dehydration and multi-field coupled demulsification and coalescence according to claim 1 is characterized in that: The multi-field coupled demulsification coalescence dehydrator comprises: a housing having the second inlet, the second oil phase outlet and the second water phase outlet; A centrifugal separation assembly, comprising a centrifugal separation impeller, a variable frequency motor, a conductive slip ring and a grounding electrode, wherein the centrifugal separation impeller is arranged in the housing and comprises a rotating electrode shaft and blades arranged on the periphery of the rotating electrode shaft, the variable frequency motor is connected to the rotating electrode shaft, the conductive slip ring is sleeved on the rotating electrode shaft and connected to the grounding electrode; A pulse assembly, comprising an annular electrode plate and a pulse power supply, wherein the annular electrode plate is disposed in the housing and electrically connected to the pulse power supply; The ultrasonic component comprises an ultrasonic transducer and an ultrasonic generator. The ultrasonic transducer is arranged in the shell and is electrically connected to the ultrasonic generator.

3. The high-efficiency dehydration treatment device based on layered pre-dehydration and multi-field coupled demulsification and coalescence according to claim 2 is characterized in that: The output end of the variable frequency motor is connected to the rotating electrode shaft through a transition coupling and an insulating connector.

4. The high-efficiency dehydration treatment device based on layered pre-dehydration and multi-field coupled demulsification and coalescence according to claim 2 is characterized in that: The surface of the annular electrode plate is coated with insulating material; and / or The inner wall surface of the housing is provided with a hydrophobic insulating layer; and / or The number of the blades is 6-12; and / or The speed of the variable frequency motor is 0-6000r / min.

5. The high-efficiency dehydration treatment device based on layered pre-dehydration and multi-field coupled demulsification and coalescence according to claim 2 is characterized in that: The housing comprises a cylindrical main body for accommodating the centrifugal separation impeller, the annular electrode plate and the ultrasonic transducer, and the ratio of the inner diameter of the ultrasonic transducer to the diameter of the main body is 1 / 3-2 / 3.

6. The high-efficiency dehydration treatment device based on layered pre-dehydration and multi-field coupled demulsification and coalescence according to claim 1 is characterized in that: The stratified pre-dehydrator pre-separates the crude oil introduced from the first inlet into a water layer, an emulsion layer and an oil layer based on gravity and / or electric field.

7. The high-efficiency dehydration treatment device based on layered pre-dehydration and multi-field coupled demulsification and coalescence according to claim 1 is characterized in that: The number of the stratified pre-dehydrators is two, and the two stratified pre-dehydrators are arranged in parallel; and / or There are two cyclone dehydrators, the third inlet of one cyclone dehydrator is connected to the first water phase outlet, and the third inlet of another cyclone dehydrator is connected to the second water phase outlet.

8. A dehydration method, characterized in that: The method is implemented by using the high-efficiency dehydration treatment device described in any one of claims 1 to 7, comprising the following steps: The stratified pre-dehydrator is used to pre-separate the crude oil transported from the first inlet into a water layer, an emulsion layer and an oil layer, and the separated oil, emulsion and water are transported to the oil storage tank, the multi-field coupled demulsification coalescence dehydrator and the cyclone dehydrator through the first oil phase outlet, the emulsion outlet and the first water phase outlet respectively; The demulsifier is added to the emulsion and / or light phase transported to the multi-field coupled demulsification coalescing dehydrator by using the demulsifier adder; The multi-field coupled demulsification coalescence dehydrator is used to separate the emulsion and / or light phase into a water phase and an oil phase, and the separated oil phase and water phase are transported to an oil storage tank and a cyclone dehydrator through a second oil phase outlet and a second water phase outlet, respectively; A cyclone dehydrator is used to separate the water phase transported from the third inlet into a light phase and a water phase, and the separated light phase and water phase are transported to a multi-field coupled demulsification coalescence dehydrator and a sewage storage tank through a light phase outlet and a third water phase outlet, respectively.

9. The dehydration method according to claim 8, characterized in that: The multi-field coupled demulsification coalescence dehydrator separates the emulsion and / or light phase into a water phase and an oil phase based on the synergistic effect of an electric field, a centrifugal separation field and ultrasonic waves.

10. The dehydration method according to claim 8, characterized in that: The oil-water ratio of the oil phase delivered to the oil storage tank is detected by an oil-water ratio analyzer, and the oil phase with the oil-water ratio meeting the standard is delivered to the oil storage tank.

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