An oil-water separation experimental system with electric, magnetic and ultrasonic synergistic effect

Abstract

The present disclosure provides an efficient oil-water separation experimental system with electric, magnetic and ultrasonic synergistic effect, which comprises an electric field generating system, a magnetic field excitation system, an ultrasonic wave generating system and a test sample tank; the electric field generating system is configured such that the test sample tank is located in the electric field generated by the electric field generating system; the magnetic field excitation system is configured such that the test sample tank is located in the magnetic field generated by the magnetic field excitation system; the ultrasonic wave generating system is configured such that the test sample tank is located in the ultrasonic wave field generated by the ultrasonic wave generating system; the magnetic field excitation system and the ultrasonic wave generating system are each independently rotated at any angle with the body center of the test sample tank as the center. By simultaneously changing the electric field parameters, the magnetic field parameters, the acoustic field parameters, the synergistic conditions and the physical and chemical properties of oil and water, the oil-water separation characteristics of crude oil emulsion under the synergistic effect of electric field, magnetic field and ultrasonic wave are quickly and accurately evaluated.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of oil and gas gathering and transportation system multiphase separation, and particularly relates to an efficient oil-water separation experimental system with synergistic effect of electricity, magnetism and ultrasound. BACKGROUND

[0002] With the development of major oil fields into the middle and late stages, enhanced oil recovery methods such as water injection, agent injection and polymer injection are increasingly widely used, and the emulsification degree of the oil-water mixture collected from the wellhead is increasingly serious. The increase of water content in crude oil increases the invalid work ratio of the power system, increases the invalid heat energy ratio of the thermal system, and is also prone to cause corrosion and fouling of storage and transportation equipment. Therefore, it is of great significance to study the efficient oil-water separation technology of crude oil emulsion for improving the safe and stable operation of the crude oil gathering and transportation system.

[0003] The electric dehydration technology can effectively promote the movement and coalescence of water droplets in the emulsion. The crude oil electric dehydrator developed based on the electric field action mechanism has become a key equipment for crude oil treatment in petrochemical enterprises such as refineries and oilfield stations. When the emulsion droplets pass through the high-intensity electric field, the water droplets in the emulsion droplets are polarized and charged to form dipoles, which are arranged in a straight line in the direction of the electric line. The electric attraction force makes the adjacent water droplets close, contact and aggregate to be separated by sedimentation. Although increasing the electric field strength is conducive to improving the dehydration rate, when the electric field strength exceeds the critical field strength, the water droplets at both ends become sharp and split into extremely small water droplets, which is counterproductive.

[0004] The prior art discloses an oil-water separation technology coupling electric field and magnetic field based on traditional electric dehydration method, and proves that the treatment effect of electromagnetic field synergistic treatment of water-in-oil emulsion is better than that of electric field or magnetic field single field effect. Chinese patent CN111171859A discloses a segmented electromagnetic coupling separator for treating oilfield produced liquid, which is composed of a separator tank, a gas-liquid separation module, a high-water-content electromagnetic synergistic dehydration module, a low-water-content electric dehydration module, a power supply system, a liquid level controller, a gas outlet, an oil collection pipe and a water outlet. The oilfield produced liquid is preliminarily treated by electromagnetic synergistic effect and finally realizes oil-water separation by the orthogonal effect of electric field and sedimentation, but the device uses two groups of magnets to generate magnetic field, which is difficult to realize the regulation and control of magnetic field parameters and is difficult to adapt to complex working conditions. Chinese patent CN108658181A discloses a high-efficiency electromagnetic synchronous synergistic oil-water separation system, which is composed of a strengthening coalescence device and a sedimentation separation device. The strengthening coalescence device applies electric field and magnetic field orthogonal distribution synchronous synergistic effect to the emulsion, so that the liquid droplets in the oil coalesce, and the oil-water separation is realized by the sedimentation separation device. However, the system has a large sedimentation space, the equipment is relatively complex, and the cost is high. In summary, the existing electromagnetic field coupling technology mainly focuses on the operation and design of specific devices, and it is difficult to observe and study the crude oil dehydration law under controllable and variable external field parameters and oil-water physical and chemical properties. Moreover, the system has high cost, large volume and great limitations.

[0005] In addition, the ultrasonic method has the advantages of wide adaptability, simple equipment and low cost as a new type of demulsification method. Ultrasonic wave is an elastic mechanical wave propagating in a medium. Under the action of mechanical vibration, water droplets and oil phase vibrate together. Due to the difference in water droplet size and oil-water physical and chemical properties, water droplets move directionally and accumulate at the nodes or loops of pressure with different relative vibration speeds, and collide and adhere to each other during migration and aggregation. Then, under the action of sound field driving force and double-layer attraction force, they coalesce into large water droplets. Chinese patent CN105891207A discloses a device and method for testing micro characteristics of water droplets in oil under the action of ultrasonic and electric field. The device uses high-speed photography and optical magnification technology to obtain the micro characteristics of water droplets in oil under the action of electric field or ultrasonic field, and evaluates the micro evolution law of water droplets in oil under the action of electric field and ultrasonic field by changing the external field parameters. However, the device focuses on the study of micro behavior of droplets, and it is difficult to control the oil-water separation efficiency from the macroscopic point of view. Moreover, the sound field driving force often cannot overcome the steric hindrance effect between dispersed water droplets in high-viscosity oil-water emulsion, and the consideration of the effect of electric field and ultrasonic field on the improvement of oil-water separation efficiency is limited.

[0006] In summary, the existing electric dehydration technology is limited in strengthening the dehydration performance of crude oil emulsion due to the influence of electric field intensity; the existing electromagnetic field coupling oil-water separation technology is difficult to realize the research and observation on the mechanism and influence law of electromagnetic synergistic treatment of water-in-oil emulsion; and the existing ultrasonic demulsification technology has low separation efficiency. SUMMARY

[0007] The following is a summary of the subject matter of the detailed description herein. This summary is not intended to limit the scope of the claims.

[0008] The technical solution provided by the present disclosure is used for testing the oil-water separation efficiency of crude oil emulsion under electric field, magnetic field and ultrasonic wave and researching the influence law of each physical field parameter and oil-water physical and chemical property on the dehydration performance of crude oil.

[0009] In order to solve the above problems of the prior art, the purpose of the present disclosure is to provide an oil-water separation experimental system with high-efficiency electric, magnetic and ultrasonic synergistic effect, which can explore the mechanism of electric field, magnetic field and ultrasonic wave in strengthening the treatment of crude oil emulsion, test the oil-water separation efficiency of crude oil emulsion under the action of electric field, magnetic field and ultrasonic wave, quickly and accurately evaluate the influence law of electric field parameter, magnetic field parameter, acoustic field parameter, synergistic condition and oil-water physical and chemical property on the oil-water separation efficiency, and obtain the external field characteristic parameter reaching the optimal oil-water separation efficiency. The research results of the system can provide basic data for the theoretical research and industrial optimization of the oil-water separation characteristics of crude oil emulsion under multiple physical fields.

[0010] In an embodiment of the present disclosure, an oil-water separation experimental system with high-efficiency electric, magnetic and ultrasonic synergistic effect is provided, which comprises an electric field generating system, a magnetic field excitation system, an ultrasonic wave generating system and a test sample tank.

[0011] The electric field generating system is configured such that the test sample tank is located in the electric field generated by the electric field generating system.

[0012] The magnetic field excitation system is configured such that the test sample tank is located in the magnetic field generated by the magnetic field excitation system.

[0013] The ultrasonic wave generating system is configured such that the test sample tank is located in the ultrasonic wave field generated by the ultrasonic wave generating system.

[0014] The magnetic field excitation system and the ultrasonic wave generating system are each independently rotatable at any angle with the body center of the test sample tank as the center.

[0015] In an embodiment provided by the present disclosure, the magnetic field generated by the magnetic field excitation system is parallel to the liquid plane of the test sample tank, that is, perpendicular to the direction of the electric field.

[0016] In an embodiment provided in the present disclosure, the liquid plane of the ultrasonic field generated by the ultrasonic wave generating system is parallel, i.e. perpendicular to the direction of the electric field and / or the direction of the magnetic field.

[0017] In an embodiment provided in the present disclosure, the ultrasonic frequency of the ultrasonic field satisfies formula (1):

[0018] L = v / 2f … … … (1)

[0019] In formula (1), L is the height of the crude oil emulsion, m; v is the sound speed in the crude oil emulsion, m / s; f is the ultrasonic frequency of the ultrasonic field, Hz.

[0020] In an embodiment provided in the present disclosure, the inner length of the test tank is 50mm to 100mm, the inner height of the test tank is 50mm to 100mm, and the inner depth of the test tank is 50mm to 100mm; the wall thickness of the test tank is 0.5mm to 5mm.

[0021] In an embodiment provided in the present disclosure, the tank wall of the test tank is further provided with a liquid inlet and a liquid outlet, the liquid inlet is in communication with a sample tank to be tested, and the liquid outlet is in communication with a waste liquid tank.

[0022] In an embodiment provided in the present disclosure, the material of the test tank is transparent material, and the outer wall surface of the test tank is marked with a scale;

[0023] The electric field generating system, the magnetic field excitation system and the ultrasonic wave generating system are each independently turned on or turned off.

[0024] In an embodiment provided in the present disclosure, the electric field generating system comprises:

[0025] A top electrode plate is arranged above the test tank.

[0026] A bottom electrode plate is arranged below the test tank.

[0027] An alternating current power supply is in electrical communication with the top electrode plate and the bottom electrode plate.

[0028] In an embodiment provided in the present disclosure, the top of the tank is attached to the top electrode plate; the bottom of the tank is attached to the bottom electrode plate.

[0029] In an embodiment provided in the present disclosure, the top electrode plate and the bottom electrode plate are both polished brass material, and are both coated with an insulating material on the surface.

[0030] In an embodiment provided by the present disclosure, the electric field generating system comprises an alternating current power supply and an oscilloscope; a voltage detection port I of the alternating current power supply is connected to a voltage input port II of the oscilloscope, and a current detection port II is connected to a current input port I of the oscilloscope;

[0031] The top electrode plate is connected to a voltage output port IV of the alternating current power supply, and the bottom electrode plate is grounded to the negative electrode port III of the alternating current power supply, so as to generate an alternating current electric field.

[0032] In an embodiment provided by the present disclosure, the magnetic field excitation system comprises:

[0033] An electromagnet; the electromagnet is configured to form a magnetic field.

[0034] The ultrasonic wave generating system comprises:

[0035] An ultrasonic wave generator, which is configured to form an ultrasonic wave field.

[0036] In another aspect, the present disclosure provides an oil-water separation experimental method using the above system, which comprises the following steps:

[0037] After calculating the water content of the sample to be tested, the sample to be tested is injected into the test sample groove;

[0038] According to the experimental requirements, the flow of the sample to be tested in the test sample groove is adjusted, the positions of the electromagnet and the ultrasonic wave generator are adjusted, the electric field parameters are adjusted and the electric field is output, the magnetic field parameters are adjusted and the magnetic field is output, and the ultrasonic wave field parameters are adjusted and the ultrasonic wave field is output;

[0039] After the processing according to the experimental requirements is completed, the oil sample in the upper part of the sample to be tested is taken to calculate the water content; the upper part is more than 20% of the upper part in the overall height direction of the sample to be tested;

[0040] In an embodiment provided by the present disclosure, the above experimental process can be repeated by changing the electric field, magnetic field and acoustic field parameters, processing time and processing sequence to meet the above experimental requirements.

[0041] In an embodiment provided by the present disclosure, the electric field strength is 0 kV / m to 320 kV / m.

[0042] In an embodiment provided by the present disclosure, the magnetic field strength is 0 T to 0.5 T.

[0043] In an embodiment provided by the present disclosure, the ultrasonic wave field strength is 0 W / m 2 to 400 W / m 2 .

[0044] In an embodiment provided by the present disclosure, the volume of the sample to be tested accounts for 20% to 80% of the volume of the test sample groove.

[0045] In an embodiment provided by the present disclosure, the volume of the sample to be tested in the test sample groove is 90 mL to 360 mL.

[0046] In another aspect, provided in the embodiments of the present disclosure is a method for obtaining parameters of multiphase separation of an oil and gas gathering and transportation system, the multiphase separation of the oil and gas gathering and transportation system comprising using any one of an electric field, a magnetic field and an ultrasonic field,

[0047] The method comprises:

[0048] Using the experimental system described above, the electric field strength, the magnetic field strength and the ultrasonic field strength of the sample to be tested are obtained when the designed oil-water separation effect is achieved;

[0049] The electric field strength and the ultrasonic field strength are brought into the following formula to obtain the voltage amplitude required in actual production to achieve the electric field strength and the sound pressure amplitude required in actual production to achieve the ultrasonic field strength:

[0050] E=U1 / d1=f E (d2 / d1,U2 / U1)g E (σ2 / σ1,ε2 / ε1)U2 / d2……………(2)

[0051] In formula (2), E is the electric field strength, kV / m; U1 is the voltage amplitude of the electric field generating system, kV; d1 is the electrode plate spacing of the electric field generating system, m; U2 is the voltage amplitude required in actual production, kV; and d2 is the electrode plate spacing in actual production, m;

[0052] f E (d2 / d1,U2 / U1) is a correction coefficient of distortion effect of non-ideal parallel plate edge electric field lines, dimensionless, and is related to the ratio d2 / d1 of the actual electrode plate spacing to the electrode plate spacing of the electric field generating system and the ratio U2 / U1 of the actual voltage amplitude to the voltage amplitude of the electric field generating system. The larger the d2 / d1 is, the smaller the value of the parameter is, and the larger the U2 / U1 is, the larger the value of the parameter is;

[0053] g E(σ2 / σ1, ε2 / ε1) is a correction coefficient of electric energy loss due to leakage, polarization, etc., dimensionless, and the value is 0.60 to 0.99, which is related to the ratio of electric conductivity σ2 / σ1 of the crude oil emulsion in actual production and the crude oil emulsion in the experimental system and the ratio of dielectric constant ε2 / ε1 of the crude oil emulsion in actual production and the crude oil emulsion in the experimental system; the larger σ2 / σ1 is, the larger the value of the parameter is, and the larger ε2 / ε1 is, the smaller the value of the parameter is;

[0054] σ2 is the electric conductivity of the crude oil emulsion in actual production, mS / m; σ1 is the electric conductivity of the crude oil emulsion in the experimental system, mS / m; ε2 is the dielectric constant of the crude oil emulsion in actual production, nF / m; and ε1 is the dielectric constant of the crude oil emulsion in the experimental system, nF / m.

[0055]

[0056] In formula (3), I is the field intensity of the ultrasonic wave field, W / m 2 ; P1 is the sound pressure amplitude of the ultrasonic wave generating system, Pa; ρ1 is the density of the crude oil emulsion in the experimental system, kg / m 3 ; P2 is the required sound pressure amplitude in actual production, Pa; ρ2 is the density of the crude oil emulsion in actual production, kg / m 3 ; c is the sound velocity, m / s;

[0057] is a correction coefficient of attenuation of the ultrasonic wave due to diffusion, absorption, etc., dimensionless, and the value is 0.80 to 0.99, which is related to the ratio P2 / P1 of the sound pressure amplitude in actual production and the sound pressure amplitude of the ultrasonic wave generating system and the square root of the density difference of the crude oil emulsion in actual production and the crude oil emulsion in the experimental system and the density of water ; the larger P2 / P1 is, the smaller the value of the parameter is, and the larger , the larger the value of the parameter is;

[0058] is an interface reflection correction coefficient of the ultrasonic wave, dimensionless, and the value is 0.40 to 0.99, which is related to the ratio of the density difference of the crude oil emulsion in actual production and the crude oil emulsion in the experimental system and the density of water and the ratio of the density difference of the crude oil emulsion in actual production and the crude oil emulsion in the experimental system and the viscosity of water ρ w is the density of water, and the value is 1000 kg / m 3 ; η w is the viscosity of water, and the value is generally 1 mPa·s; η1 is the viscosity of the crude oil emulsion in the experimental system, mPa·s; and η2 is the viscosity of the crude oil emulsion in actual production, mPa·s.

[0059] The viscosity of the crude oil emulsion is mPa·s; the greater the value of the parameter is, the smaller the value of the parameter is, and the greater the value of the parameter is, the smaller the value of the parameter is. The greater the value of the parameter is, the smaller the value of the parameter is, and the greater the value of the parameter is, the smaller the value of the parameter is. The greater the value of the parameter is, the smaller the value of the parameter is, and the greater the value of the parameter is, the smaller the value of the parameter is.

[0060] The beneficial effects of the present disclosure are:

[0061] The experimental system has the advantages of reasonable and compact structure, safe and flexible control, simple and convenient operation, accurate evaluation of the influence of electric field parameters on the oil-water separation performance of crude oil emulsion, accurate evaluation of the influence of magnetic field parameters on the oil-water separation performance of crude oil emulsion, accurate evaluation of the influence of ultrasonic wave parameters on the oil-water separation performance of crude oil emulsion, and rapid and accurate evaluation of the change rule of the oil-water separation performance of crude oil emulsion under the synergistic action of electric field, magnetic field and acoustic field. The experimental system has the advantages of reasonable and compact structure, safe and flexible control, high efficiency and energy saving, strong practicability and low cost.

[0062] Other features and advantages of the present disclosure will be described in the following description, and some will become apparent from the description, or will be learned from the practice of the present disclosure. Other advantages of the present disclosure can be achieved by the schemes described in the specification. BRIEF DESCRIPTION OF DRAWINGS

[0063] The accompanying drawings are used to provide an understanding of the technical solutions of the present disclosure, and constitute a part of the specification, and together with the embodiments of the present disclosure, are used to explain the technical solutions of the present disclosure, and do not constitute a limitation on the technical solutions of the present disclosure.

[0064] Figure 1 It is a schematic diagram of the overall structure of the present disclosure.

[0065] In the figure: 1, AC power supply; 2, oscilloscope; 3, electromagnet; 4, DC power supply; 5, high-frequency power meter; 6, high-frequency power amplifier; 7, signal generator; 8, ultrasonic transducer; 9, test sample tank; 10, top electrode plate; 11, bottom electrode plate. DETAILED DESCRIPTION

[0066] In order to make the purpose, technical scheme and advantages of the present disclosure more clear and apparent, the embodiments of the present disclosure are described in detail below. It should be noted that the embodiments in the present disclosure and the features in the embodiments can be combined with each other arbitrarily without conflict.

[0067] An oil-water separation experimental system with high efficiency of electric, magnetic and ultrasonic synergistic effect is exemplarily provided in the embodiments of the present disclosure, and the system comprises an electric field generating system, a magnetic field excitation system, an ultrasonic wave generating system and a test sample tank.

[0068] The electric field generating system is configured such that the test sample tank is located in an electric field generated by the electric field generating system.

[0069] The magnetic field excitation system is configured such that the test sample tank is located in a magnetic field generated by the magnetic field excitation system.

[0070] The ultrasonic wave generating system is configured such that the test sample tank is located in an ultrasonic wave field generated by the ultrasonic wave generating system.

[0071] The magnetic field excitation system and the ultrasonic wave generating system are each independently rotatable at any angle with a body center of the test sample tank as the center.

[0072] Exemplarily, an ultrasonic frequency of the ultrasonic wave field satisfies formula (1):

[0073] L = v / 2f ………………………………………(1)

[0074] In formula (1), L is the height of the crude oil emulsion, m; v is the speed of sound in the crude oil emulsion, m / s; and f is the ultrasonic frequency of the ultrasonic wave field, Hz.

[0075] Exemplarily, the inner length of the test sample tank is 50 mm to 100 mm, the inner height of the test sample tank is 50 mm to 100 mm, and the inner depth of the test sample tank is 50 mm to 100 mm; and the wall thickness of the test sample tank is 0.5 mm to 5 mm.

[0076] Exemplarily, the test sample tank is further provided with a liquid inlet and a liquid outlet on the tank wall, the liquid inlet is in communication with a sample tank to be tested, and the liquid outlet is in communication with a waste liquid tank.

[0077] Exemplarily, the material of the test sample tank is a transparent material, and the outer wall surface of the test sample tank is marked with a scale;

[0078] The electric field generating system, the magnetic field excitation system and the ultrasonic wave generating system are each independently turned on or turned off.

[0079] Exemplarily, the electric field generating system comprises:

[0080] a top electrode plate arranged above the test sample tank;

[0081] a bottom electrode plate arranged below the test sample tank;

[0082] An alternating current power supply in electrical communication with the top electrode plate and the bottom electrode plate.

[0083] Exemplarily, the top of the sample groove is attached to the top electrode plate; and the bottom of the sample groove is attached to the bottom electrode plate.

[0084] Exemplarily, the top electrode plate and the bottom electrode plate are both polished brass and are both coated with an insulating material on the surface.

[0085] Exemplarily, the electric field generating system comprises an alternating current power supply and an oscilloscope; a voltage detection port I of the alternating current power supply is connected to a voltage input port II of the oscilloscope; and a current detection port II is connected to a current input port I of the oscilloscope.

[0086] The top electrode plate is connected to a voltage output port IV of the alternating current power supply; and the bottom electrode plate is connected to a negative electrode port III of the alternating current power supply for grounding, so as to generate an alternating current electric field.

[0087] Exemplarily, the magnetic field excitation system comprises:

[0088] An electromagnet configured to form a magnetic field.

[0089] The ultrasonic wave generating system comprises:

[0090] An ultrasonic wave generator configured to form an ultrasonic wave field.

[0091] In another aspect, the present disclosure exemplarily provides an oil-water separation experimental method using the above system, which comprises the following steps:

[0092] After calculating the water content of the sample to be tested, the sample to be tested is injected into the test sample groove.

[0093] According to the experimental requirements, the flow of the sample to be tested in the test sample groove is adjusted, the positions of the electromagnet and the ultrasonic wave generator are adjusted, the electric field parameters are adjusted and the electric field is output, the magnetic field parameters are adjusted and the magnetic field is output, the ultrasonic wave field parameters are adjusted and the ultrasonic wave field is output.

[0094] After the processing according to the experimental requirements is completed, the oil sample at the upper part of the sample to be tested is taken to calculate the water content; the upper part is more than 20% of the upper part in the overall height direction of the sample to be tested.

[0095] Exemplarily, the above experimental process can be repeated by changing the electric field, magnetic field and acoustic field parameters, processing time and processing sequence to meet the above experimental requirements.

[0096] Exemplarily, the electric field strength is 0 kV / m to 320 kV / m.

[0097] Exemplarily, the magnetic field strength is 0T to 0.5T.

[0098] Exemplarily, the ultrasonic field strength is 0W / m 2 to 400W / m 2 .

[0099] Exemplarily, the volume of the sample to be tested accounts for 20% to 80% of the volume of the test sample groove.

[0100] Exemplarily, the volume of the sample to be tested in the test sample groove is 90mL to 360mL.

[0101] In another aspect, the disclosure exemplarily provides an acquisition method of a multiphase separation parameter of an oil and gas gathering and transportation system, the multiphase separation of the oil and gas gathering and transportation system including using any one of an electric field, a magnetic field and an ultrasonic field,

[0102] The method comprises:

[0103] Using the experimental system described above, the electric field strength, the magnetic field strength and the ultrasonic field strength of the sample to be tested are acquired when the designed oil-water separation effect is achieved;

[0104] The electric field strength and the ultrasonic field strength are brought into the following formula to obtain the voltage amplitude required to achieve the electric field strength in actual production and the sound pressure amplitude required to achieve the ultrasonic field strength in actual production:

[0105] E=U1 / d1=f E (d2 / d1,U2 / U1)g E (σ2 / σ1,ε2 / ε1)U2 / d2……………(2)

[0106] In formula (2), E is the electric field strength, kV / m; U1 is the voltage amplitude of the electric field generation system, kV; d1 is the electrode plate spacing of the electric field generation system, m; U2 is the voltage amplitude required in actual production, kV; and d2 is the electrode plate spacing in actual production, m;

[0107] f E (d2 / d1,U2 / U1) is a distortion effect correction coefficient of a non-ideal parallel plate edge electric field line, dimensionless, and is related to the ratio d2 / d1 of the actual electrode plate spacing to the electrode plate spacing of the electric field generation system and the ratio U2 / U1 of the actual voltage amplitude to the voltage amplitude of the electric field generation system. The larger the d2 / d1 is, the smaller the parameter value is, and the larger the U2 / U1 is, the larger the parameter value is;

[0108] g E(σ2 / σ1, ε2 / ε1) is a correction coefficient of electric energy loss due to leakage, polarization, etc., dimensionless, and the value is 0.60 to 0.99, which is related to the ratio of the conductivity σ2 / σ1 of the crude oil emulsion in the actual production and the conductivity σ1 of the crude oil emulsion in the experimental system, and the ratio of the dielectric constant ε2 / ε1 of the crude oil emulsion in the actual production and the dielectric constant ε1 of the crude oil emulsion in the experimental system; the larger the σ2 / σ1 is, the larger the value of the parameter is, and the larger the ε2 / ε1 is, the smaller the value of the parameter is;

[0109] σ2 is the conductivity of the crude oil emulsion in the actual production, mS / m; σ1 is the conductivity of the crude oil emulsion in the experimental system, mS / m; ε2 is the dielectric constant of the crude oil emulsion in the actual production, nF / m; and ε1 is the dielectric constant of the crude oil emulsion in the experimental system, nF / m.

[0110]

[0111] In formula (3), I is the field intensity of the ultrasonic wave field, W / m 2 ; P1 is the sound pressure amplitude of the ultrasonic wave generating system, Pa; ρ1 is the density of the crude oil emulsion in the experimental system, kg / m 3 ; P2 is the required sound pressure amplitude in the actual production, Pa; ρ2 is the density of the crude oil emulsion in the actual production, kg / m 3 ; c is the sound velocity, m / s;

[0112] is a correction coefficient of the attenuation of the ultrasonic wave due to diffusion, absorption, etc., dimensionless, and the value is 0.80 to 0.99, which is related to the ratio P2 / P1 of the sound pressure amplitude in the actual production and the sound pressure amplitude of the ultrasonic wave generating system, and the square root of the density difference of the crude oil emulsion in the actual production and the crude oil emulsion in the experimental system and the density of water ; the larger the P2 / P1 is, the smaller the value of the parameter is, and the larger the density difference is, the larger the value of the parameter is;

[0113] is an interface reflection correction coefficient of the ultrasonic wave, dimensionless, and the value is 0.40 to 0.99, which is related to the ratio of the density difference of the crude oil emulsion in the actual production and the crude oil emulsion in the experimental system and the density of water , and the ratio of the density difference of the crude oil emulsion in the actual production and the crude oil emulsion in the experimental system and the viscosity of water ρ w is the density of water, and the value is 1000 kg / m 3 ; η w is the viscosity of water, and the value is generally 1 mPa·s; η1 is the viscosity of the crude oil emulsion in the experimental system, mPa·s; and η2 is the viscosity of the crude oil emulsion in the actual production, mPa·s; when The greater the parameter value is, the smaller the parameter value is, and the greater the parameter value is, the smaller the parameter value is. The greater the parameter value is, the smaller the parameter value is.

[0114] Exemplarily, the present disclosure provides the following embodiment 1

[0115] The functional effects of the present disclosure are specifically illustrated by the following examples.

[0116] As Figure 1 shown, an efficient oil-water separation experimental system with synergistic effect of electric field, magnetic field and ultrasonic wave includes an electric field generating system, a magnetic field excitation system, an ultrasonic wave generating system and a sample tank system.

[0117] The electric field generating system includes:

[0118] An alternating current power supply 1, an oscilloscope 2, a top electrode plate 10 and a bottom electrode plate 11; the voltage detection port I of the alternating current power supply 1 is connected with the voltage input port II of the oscilloscope 2, and the current detection port II is connected with the current input port I of the oscilloscope 2, so as to monitor the voltage and current signals; the top electrode plate 10 is connected with the voltage output port IV of the alternating current power supply 1, and the bottom electrode plate 11 is grounded through the negative port III of the alternating current power supply 1, so as to generate an alternating current electric field. The top electrode plate 10 and the bottom electrode plate 11 in the sample tank system are respectively adhered to the top and the bottom of a sample tank 9 containing crude oil emulsion, so that the electric field direction in the sample tank 9 is vertical from top to bottom, that is, the electric field in the negative direction of Z axis is applied; the sample tank 9 in the sample tank system is made of organic glass, and the outer wall is marked with a scale, and the top is openable for adding crude oil emulsion.

[0119] In this embodiment, a 20 / 20C type high-voltage alternating current power supply is used, which can output an electric field signal with a voltage in the range of 0-±20kV and a frequency in the range of 0-20kHz; a TDS2002B type oscilloscope is used to monitor the output voltage, current, frequency and other electric field parameters in real time.

[0120] Under the action of the electric field, the liquid droplets in the oil occur dipole coalescence, electrophoretic coalescence, dielectrophoretic coalescence and oscillation coalescence, thereby promoting the coalescence of water droplets, increasing the particle size and improving the dehydration effect of the crude oil emulsion to a certain extent.

[0121] The magnetic field excitation system includes:

[0122] An electromagnet 3 and a direct current power supply 4; the electromagnet 3 is connected with the positive port I and the negative port II of the direct current power supply 4, so as to generate a constant and stable magnetic field; the electromagnet 3 in the magnetic field excitation system is horizontally placed along the axis direction of the sample tank, so that the magnetic field direction in the sample tank 9 is horizontal from right to left and parallel to the liquid plane, and perpendicular to the electric field direction, that is, the magnetic field in the negative direction of X axis is applied.

[0123] In this embodiment, the HCP series 220V DC power supply is used to supply power to the PEM-5005H electromagnet, and the electric field intensity of the control DC power supply is about 270kV / m. By adjusting the DC power supply voltage, the magnetic field strength can be changed, and a magnetic field strength in the range of 0 to 0.5T can be generated.

[0124] Under the joint action of the electric field and the magnetic field, the motion trajectory of the water droplets in the oil changes from short free travel planar reciprocating motion to high degree of freedom three-dimensional spiral motion, increasing the collision probability of the droplet group and accelerating the coalescence separation process of the water phase from the multiphase system. At the same time, the adsorption rate of water molecules to the surface of wax molecules is changed by the action of the magnetic field, so that the hydrophobic property of the wax crystal is also enhanced, so that the crystal grain is more easily migrated on the oil-water interface under the action of the electric field, reducing the stability of the crude oil emulsion and greatly promoting the oil-water separation. By matching different directions and different field strengths of the electric field and the magnetic field, combined with different oil-water ratios and temperatures of the crude oil emulsion, the most suitable electric field direction, electric field strength, magnetic field direction and magnetic field strength for oil-water separation are matched.

[0125] The ultrasonic wave generating system comprises:

[0126] A high-frequency power meter 5, a high-frequency power amplifier 6, a signal generator 7 and an ultrasonic transducer 8; the power measurement positive port I and the power measurement negative port II of the high-frequency power meter 5 are connected with the power detection positive port I and the power detection negative port II of the high-frequency power amplifier 6 respectively, so as to monitor the performance parameters of the ultrasonic wave; the signal input port III of the high-frequency power amplifier 6 is connected with the signal output port I of the signal generator 7, and the signal generator 7 is adjusted to change the ultrasonic wave parameters generated by the ultrasonic wave generating system; the ultrasonic transducer 8 is connected with the power output positive port IV and the power output negative port V of the high-frequency power amplifier 6, so that the signal generated by the signal generator 7 is transmitted to the ultrasonic transducer 8 after being amplified by the high-frequency power amplifier 6, and an ultrasonic wave field is generated; the ultrasonic transducer 8 in the ultrasonic wave generating system is placed close to the rear side outer wall surface of the test sample tank 9, so that the sound field direction in the test sample tank 9 is perpendicular to the paper surface from inside to outside, and is orthogonal to the electric field direction and the magnetic field direction, that is, the sound field of the Y-axis negative direction is applied. The ultrasonic transducer 8 is detachable, and the separation effect of the ultrasonic wave field in other directions on different phases in the oil-water emulsion can be verified.

[0127] In this embodiment, the active power and total power of the high frequency signal at both ends of the ultrasonic transducer 8 are accurately measured by using a 3332 type single-phase high frequency power meter; the ultrasonic signal is amplified by using a HFVA-62 type high frequency linear power amplifier, and is output to the ultrasonic transducer 8 through a high-voltage cable; a precise, stable, low-distortion direct current, sine wave, pulse and other signals are generated by using an AFG1022 type arbitrary waveform signal generator, and are transmitted to the high frequency power amplifier 6 through a coaxial cable; a sandwiched detachable ultrasonic transducer is used to match the frequency and power of the ultrasonic signal generated by the signal generator, and can provide an ultrasonic signal with a sound speed of 1000 m / s, a frequency of 20 kHz to 120 kHz, and a power of 0 to 400 W / m 2 .

[0128] On the basis of the electromagnetic coupling field, the ultrasonic wave is applied, so that the oil droplets are enriched in the nodes or loops of the acoustic field, the probability and degree of the operation, deformation, rupture and coalescence of the oil droplets are improved, the interfacial tension of the water in the crude oil layer is reduced, the viscosity of the crude oil emulsion is reduced, and the emulsion molecular groups are dispersed, so that the efficient oil-water separation of the crude oil emulsion under the action of the electric field, the magnetic field and the acoustic field is realized. Through the matching of different directions and different field strengths of the ultrasonic field, the electric field, the magnetic field, combined with different oil-water ratios and temperatures of the crude oil emulsion, the most suitable electric field direction, electric field strength, magnetic field direction, magnetic field strength, ultrasonic field direction and ultrasonic field strength for oil-water separation are matched.

[0129] Since the ultrasonic wave emitted by the ultrasonic transducer 8 propagates in the medium and is reflected when encountering the oil-water free interface, a reflected wave with the same frequency and amplitude as the incident wave but opposite propagation direction is formed. In order to ensure that the acoustic field after the superposition of the incident wave and the reflected wave is an ultrasonic standing wave field, it is also necessary to ensure that the phase difference between the incident wave and the reflected wave is constant, so it is necessary to control the height of the added crude oil emulsion, which should satisfy the following formula (1) so that the electric field, magnetic field and acoustic field signals received by the crude oil emulsion in the test sample tank (9) are complete and uniform.

[0130] L = v / 2f ………………………………………… (1)

[0131] In formula (1), L is the height of the added crude oil emulsion, m; v is the sound speed in the crude oil emulsion, m / s; f is the ultrasonic frequency of the ultrasonic field, Hz.

[0132] The size of the test tank used in the embodiment is 75*75*80mm, and the volume is 450mL; the size of the top electrode plate and the bottom electrode plate is 75*75mm, and the material is polished brass plate, and both are coated with PVC insulation material on the surface. The water content of the crude oil emulsion before treatment is calculated by distillation method; the top electrode plate 10 is fixed, the positions of the electromagnet 3 and the ultrasonic transducer 8 are adjusted, the electromagnet 3 is tightly attached to the outer wall surface of the left and right sides of the test tank 9, and the ultrasonic transducer 8 is tightly attached to the outer wall surface of the back side of the test tank 9; the AC power supply 1 and the oscilloscope 2 are turned on, the electric field parameters are adjusted according to the experimental requirements, and the electric field signal is output; the DC power supply 4 is turned on, the magnetic field parameters are adjusted according to the experimental requirements, and the magnetic field signal is output; the signal generator 7, the high-frequency power meter 5 and the high-frequency power amplifier 6 are turned on, the acoustic field parameters are adjusted according to the experimental requirements, and the acoustic field signal is output; the on-off of the AC power supply, the DC power supply and the signal generator is controlled according to the treatment time of the electric field, the magnetic field and the acoustic field prepared according to the experimental requirements; the treatment sequence of the electric field, the magnetic field and the acoustic field is dynamically adjusted according to the experimental requirements, and the electric field, the magnetic field and the acoustic field parameters are recorded; after the treatment is completed, the upper part of the oil sample in the test tank 9 is taken and the water content is calculated by distillation method; the electric field, the magnetic field and the acoustic field parameters, the treatment time and the treatment sequence are changed, and the above experimental process is repeated; the chemical and physical properties of the oil phase and the water phase in the crude oil emulsion to be treated are changed, and the above experimental process is repeated. In this way, the change rule of the oil-water separation performance of the crude oil emulsion under the synergistic action of the electric field, the magnetic field and the acoustic field (or under the action of one or two fields) is quickly and accurately evaluated, and the basic data for the in-depth theoretical research and industrial optimization of the oil-water separation characteristics of the crude oil emulsion under multiple physical fields are provided.

Claims

1. A method of obtaining multiphase separation parameters for an oil and gas gathering system, the method comprising: The method comprises: An oil-water separation experiment system using electric, magnetic and ultrasonic synergies is used to obtain the electric field intensity, the magnetic field intensity and the ultrasonic field intensity when the sample to be tested continuously achieves the designed oil-water separation effect; wherein the oil-water separation experiment system comprises an electric field generation system, a magnetic field excitation system, an ultrasonic wave generation system and a test sample tank; the electric field generation system is configured such that the test sample tank is located in the electric field generated by the electric field generation system; the magnetic field excitation system is configured such that the test sample tank is located in the magnetic field generated by the magnetic field excitation system; the ultrasonic wave generation system is configured such that the test sample tank is located in the ultrasonic wave field generated by the ultrasonic wave generation system; the magnetic field excitation system and the ultrasonic wave generation system each independently rotate at an arbitrary angle with the body center of the test sample tank as the center; The electric field intensity and the ultrasonic field intensity are brought into the following formula to obtain the voltage amplitude required in actual production to achieve the electric field intensity and the sound pressure amplitude required in actual production to achieve the ultrasonic field intensity: E = U1 / d1 = f E (d2 / d1, U2 / U1)g E (σ2 / σ1, ε2 / ε1) U2 / d2 ………… (1) In formula (1), E is the electric field intensity, kV / m; U1 is the voltage amplitude of the electric field generation system, kV; d1 is the electrode plate spacing of the electric field generation system, m; U2 is the voltage amplitude required in actual production, kV; d2 is the electrode plate spacing in actual production, m; f E (d2 / d1, U2 / U1) is a correction coefficient of distortion effect of non-ideal parallel plate edge electric field lines, dimensionless, and the value is 0.75 to 0.99, which is related to the ratio of the actual electrode plate spacing and the electrode plate spacing of the electric field generating system d2 / d1 and the ratio of the actual and the voltage amplitude of the electric field generating system U2 / U1; the larger d2 / d1 is, the smaller the multiphase separation parameter value is, and the larger U2 / U1 is, the larger the multiphase separation parameter value is; g E (σ2 / σ1, ε2 / ε1) is a correction factor of electric energy loss, dimensionless, and has a value of 0.60 to 0.99, and is related to the ratio of the conductivity σ2 / σ1 of the crude oil emulsion in actual production and the conductivity σ1 of the crude oil emulsion in the experimental system, and the ratio of the dielectric constant ε2 / ε1 of the crude oil emulsion in actual production and the dielectric constant ε1 of the crude oil emulsion in the experimental system; the larger σ2 / σ1 is, the larger the multiphase separation parameter is; the larger ε2 / ε1 is, the smaller the multiphase separation parameter is; σ2 is the conductivity of the crude oil emulsion in actual production, mS / m; σ1 is the conductivity of the crude oil emulsion in the experiment system, mS / m; ε2 is the dielectric constant of the crude oil emulsion in actual production, ε1 is the dielectric constant of the crude oil emulsion in the experiment system, nF / m; In formula (2), I is the intensity of the ultrasonic field, W / m 2 ; P1 is the amplitude of the acoustic pressure of the ultrasonic generating system, Pa; p1 is the density of the crude oil emulsion in the experimental system, kg / m 3 ; P2 is the amplitude of the acoustic pressure required in actual production, Pa; p2 is the density of the crude oil emulsion in actual production, kg / m 3 ; c is the acoustic velocity, m / s; is a correction factor for attenuation of the ultrasonic waves, dimensionless, having a value of 0.80 to 0.99, and is a function of the ratio of the actual and the sound pressure amplitude of the ultrasonic generation system P2 / P1 and the square root of the density of the crude oil emulsion in the actual production and in the experimental system is related; the larger P2 / P1 is, the smaller the multiphase separation parameter is, and the smaller P2 / P1 is, the larger the multiphase separation parameter is is related; the larger P2 / P1 is, the smaller the multiphase separation parameter is, and the smaller P2 / P1 is, the larger the multiphase separation parameter is is the correction coefficient of ultrasonic interface reflection, dimensionless, and is in the range of 0.40 to 0.99, and is related to the ratio of the density difference between the crude oil emulsion in actual production and the crude oil emulsion in the experimental system to the water density and the ratio of the viscosity difference between the crude oil emulsion in actual production and the crude oil emulsion in the experimental system to the water viscosity ρ w is the density of water, and is 1000 kg / m 3 ; η w is the viscosity of water, and is generally 1 mPa·s; η1 is the viscosity of the crude oil emulsion in the experimental system, mPa·s; η2 is the viscosity of the crude oil emulsion in actual production, mPa·s; when is larger, the multiphase separation parameter is smaller; and when is larger, the multiphase separation parameter is smaller.

2. The method of claim 1, wherein, The ultrasonic frequency of the ultrasonic wave field satisfies formula (3): L=v / 2f………………………………………(3) In formula (3), L is the height of the crude oil emulsion, m; v is the sound speed in the crude oil emulsion, m / s; f is the ultrasonic frequency of the ultrasonic wave field, Hz.

3. The method of claim 1, wherein, The inner length of the test sample tank is 50-100 mm, the inner height of the test sample tank is 50-100 mm, and the inner depth of the test sample tank is 50-100 mm; the wall thickness of the test sample tank is 0.5-5 mm.

4. The method according to any one of claims 1 to 3, characterized in that, The test sample tank is also provided with a liquid inlet and a liquid outlet on the tank wall, the liquid inlet is in communication with a sample to be tested tank, and the liquid outlet is in communication with a waste liquid tank.

5. The method according to any one of claims 1 to 3, characterized in that, The electric field generation system comprises: A top electrode plate arranged above the test sample tank; A bottom electrode plate arranged below the test sample tank; An alternating current power supply in electrical communication with the top electrode plate and the bottom electrode plate.

6. The method of claim 1, wherein, The electric field intensity is 0 kV / m to 320 kV / m; the magnetic field intensity is 0T to 0.5T; the ultrasonic wave frequency in the ultrasonic wave field is 20 kHz to 120 kHz, and the ultrasonic wave field intensity is 0 W / m 2 to 400 W / m 2 .

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