A combined acoustic-thermochemical and electrothermochemical dehydration experimental apparatus

Abstract

This invention belongs to the field of crude oil dehydration and desalting technology, specifically relating to a combined acoustic-thermochemical and electrothermochemical dehydration experimental device. The device includes an ultrasonic demulsifier, an electrochemical dehydration tank, an explosion-proof power control cabinet, a water injection port, a water-containing crude oil injection port, a water phase outlet, a qualified oil outlet, and an electric heater. Through this experimental device, ultrasonic waves act on a large amount of aged oil circulating within the station, allowing for the determination of suitable demulsification and dehydration parameters. This reduces the amount of aged oil occupying the effective volume of dehydration equipment such as settling tanks and electrochemical dehydrators, improving the utilization rate of crude oil dehydration equipment. The intermediate layer that is difficult to remove from the electrochemical dehydrator can be returned to the ultrasonic demulsifier via process pipelines for demulsification, preventing further discharge or back-mixing, thus preventing further deterioration of oil properties and reducing vicious cycles. This invention ensures the safe operation and effective dehydration and desalting of crude oil electrochemical dehydration and desalting. Through combined dehydration tests involving ultrasound, thermal settling, thermochemical processes, and electrochemical dehydration, a set of dehydration and desalting parameters suitable for the target oil product can be simulated.

Description

Technical Field

[0001] This invention belongs to the field of crude oil dehydration and desalting technology, specifically relating to a combined acoustic-thermochemical and electrothermochemical dehydration experimental device. Background Technology

[0002] Water content in crude oil is a common phenomenon in oil and gas field development. Crude oil containing water must undergo dehydration and desalting before processing. The main methods for oil-water separation are thermal sedimentation and electrostatic dehydration / desalting, often accompanied by the addition of demulsifiers (i.e., chemical dehydration) to enhance the dehydration effect. However, some crude oils cannot be successfully separated using these traditional methods, such as oil-in-water (O / W) emulsified crude oil, wastewater recovery oil, aged oil, and certain imported oils. Due to the complexity of their chemical composition and emulsion structure, these oils are difficult to demulsify and dehydrate using thermal sedimentation, electric field methods, and chemical methods. Therefore, it is necessary to research and develop other methods to achieve demulsification, desalting, and dehydration.

[0003] Most of the salts in crude oil are soluble in the water it contains, forming a stable W / O (water-in-oil) emulsion. Therefore, crude oil desalting and dehydration occur simultaneously; the key to crude oil desalting lies in dehydration, and the key to dehydration lies in demulsification.

[0004] Aged oil, also known as aged crude oil, refers to crude oil emulsions formed during crude oil production and processing under the influence of factors such as chemicals, mechanical impurities, asphaltenes, bacteria, air, and cyclic shearing. These emulsions have become increasingly stable and cannot be treated with conventional chemicals and processing methods, thus having a significant impact on crude oil dehydration systems. The formation of aged oil is influenced by many factors, which can be summarized as follows: (1) emulsion particles formed during tertiary oil recovery; (2) emulsions formed during drilling, operations, and crude oil transportation; (3) sludge oil recovered from wastewater treatment; (4) recovered spilled oil; and (5) oily suspended solids produced by bacterial action. The aged oil generated through the aforementioned methods is mostly concentrated in settling tanks, sludge pools, and wastewater treatment plants, existing as an oil-water intermediate layer and circulating irregularly within the plant. This poses significant challenges to the operation and management of the combined plant, with the following specific impacts: First, the large amount of aged oil circulating within the plant occupies the effective volume of dehydration equipment such as settling tanks and electrostatic precipitators, reducing the utilization rate of crude oil dehydration equipment. Second, it increases the difficulty of crude oil settling and dehydration, affecting the safe operation and dehydration effect of the crude oil electrostatic precipitator. Aged oil causes a sharp decline in the dehydration effect of the electrostatic precipitator, even leading to electric field instability and reverse electric field phenomena, rendering the electrostatic precipitator inoperable. To ensure the water content of exported crude oil meets the standards, it is necessary to discharge crude oil with water content at the bottom of the purified oil tank that does not meet the export standards into the sludge pool or mix it back into the primary tank, further deteriorating the oil properties and creating a vicious cycle. Finally, it increases the cost of crude oil dehydration. Because the mixing of aged oil increases the difficulty of dehydration, the water content of the crude oil after thermochemical settling increases, and the dehydration temperature and dosage also increase rapidly.

[0005] Domestic and international research indicates that ultrasonic demulsification is a novel demulsification method that can effectively solve these problems. However, ultrasonic crude oil demulsification mainly utilizes the mechanical vibration of ultrasound waves propagating in the medium. Influenced by factors such as medium viscosity, its propagation range is limited. If the dehydration and desalting device is too large, its energy gradually decreases, reducing its effectiveness; if the device is too small, the mechanical vibration is too strong, and there is insufficient separation space for salt- and water-containing crude oils within the device. Different crude oils require different reaction conditions due to their different physicochemical properties. The level of industrialization is not high; many applications are only completed in the laboratory and have not been widely used in industrial production.

[0006] Therefore, there is an urgent need for an experimental device that can simulate multi-field coupled dehydration processes, has a wide range of adjustable parameters, and is applicable to a variety of oils. Summary of the Invention

[0007] To address the aforementioned technical problems, this invention provides a combined acoustic-thermochemical and electrothermochemical dehydration experimental device, designed to conduct dehydration and desalination experiments on different oil products, determine optimal operating parameters, provide a scientific basis for the design of industrial-scale equipment, and reduce the risk of poor treatment results from directly implementing large-scale equipment.

[0008] To achieve the above objectives, the technical solution of the present invention is as follows: A combined acoustic-thermal-chemical and electrothermal-chemical dehydration experimental device, characterized in that it includes an ultrasonic demulsification tank 1, an electric dehydration tank 2, an explosion-proof power control cabinet 3, a water inlet 4, a water-containing crude oil inlet 5, an aqueous phase outlet 6, a qualified oil outlet 7, and an electric heater 8. The ultrasonic demulsifying tank 1 includes an ultrasonic demulsifying tank body 100. The lower part of the ultrasonic demulsifying tank body 100 is provided with a first water-containing crude oil inlet 101 and a first electric heater interface 109. The upper part of the ultrasonic demulsifying tank body 100 is provided with a first oil phase outlet 102. The bottom of the ultrasonic demulsifying tank body 100 is provided with a first water washing inlet (first wastewater outlet) 103. An ultrasonic generator 106 is inserted into the top of the ultrasonic demulsifying tank body 100, extending into the tank body. The top of the ultrasonic demulsifying tank body 100 is also provided with a first temperature transmitter interface 107 and a first pressure transmitter interface 108. The tank body corresponding to the first water-containing crude oil inlet 101 is provided with a first anti-impact plate 104. The tank body corresponding to the first water washing inlet (first sewage outlet) 103 is provided with a first anti-vortex plate 105. The pipe wall of the ultrasonic demulsifying tank body 100 is provided with two first viewing windows 1010. The bottom of the ultrasonic demulsifying tank body 100 is provided with a first support leg 1011.

[0009] The electrostatic dehydration tank 2 includes an electrostatic dehydration and desalination tank body 200. The lower part of the electrostatic dehydration and desalination tank body 200 is provided with a second water-containing crude oil inlet 201 and a second electric heater interface 209. The upper part of the electrostatic dehydration and desalination tank body 200 is provided with a second oil phase outlet 202. The bottom of the electrostatic dehydration and desalination tank body 200 is provided with a second water washing inlet (second wastewater outlet) 203. The top of the electrostatic dehydration and desalination tank body 200 is provided with a high-pressure inlet 206. The lower surface of the top of the electrostatic dehydration and desalination tank body 200 is connected to an electrode plate 2013 via an insulator 2012. The lower part of the electrode plate 2013 is provided with a zero electrode orifice plate 2014 on the tank wall. The top of the electric dehydration and desalination tank body 200 is also provided with a second temperature transmitter interface 207 and a second pressure transmitter interface 208. The tank body corresponding to the second water-containing crude oil inlet 201 is provided with a second anti-impact plate 204. The tank body corresponding to the second water washing inlet (second sewage outlet) 203 is provided with a second anti-vortex plate 205. The pipe wall of the electric dehydration and desalination tank body 200 is provided with two second viewing windows 2010. The bottom of the electric dehydration and desalination tank body 200 is provided with a second support leg 2011.

[0010] The first water-containing crude oil inlet 101 is connected to the water-containing crude oil injection port 5 via a pipeline; the first water washing inlet (first sewage outlet) 103 and the second water washing inlet (second sewage outlet) 203 are connected to the water washing inlet 4 and the water phase outlet 6 via pipelines; the first oil phase outlet 102 is connected to the second water-containing crude oil inlet 201 via a pipeline; the second oil phase outlet 202 is connected to the qualified oil outlet 7 via a pipeline; the second oil phase outlet 202 is connected to the first water-containing crude oil inlet 101 and the second water-containing crude oil inlet 201 via pipelines.

[0011] The explosion-proof power control cabinet 3 consists of a power control system, a PLC control system, a display screen, a pressure display and recording module (PR), a temperature display and recording control module (TRC), a temperature alarm interlock module (TAS), a pulse power control module (PSU), and an explosion-proof cabinet shell.

[0012] An electric heater 8 is connected to the first electric heater interface 109 and the second electric heater interface 209, and the electric heater 8 is connected to the explosion-proof power control cabinet 3 via a line; the first temperature transmitter interface 107 and the second temperature transmitter interface 207 are connected to the explosion-proof power control cabinet 3 via a line; the first pressure transmitter interface 108 and the second pressure transmitter interface 208 are connected to the explosion-proof power control cabinet 3 via a line; the ultrasonic generator 106 and the high-pressure inlet 206 are connected to the explosion-proof power control cabinet 3 via a line.

[0013] The high-voltage inlet 206 includes high-voltage inlet I (positive electrode) 2061 and high-voltage inlet II (negative electrode) 2062.

[0014] A combined acoustic-thermochemical and electrothermochemical dehydration experimental method, characterized by comprising the following steps: Step 1: Inject an appropriate amount of clean water into the ultrasonic demulsifying tank and the electric demulsifying tank through the water inlet, ensuring that the water level exceeds the inlet height of the water-containing crude oil but does not exceed the electric heater. This will wash the injected crude oil, causing the oil-water interface film of some oil-in-water (O / W) particles in the oil-water mixture to break down, thereby dissolving a large number of water molecules, acid and alkali ions, and mineral salts in the free water, which will be discharged with the wash water.

[0015] Step 2: After the water wash is injected, close the crude oil outlet valve of the ultrasonic demulsifier. Inject the target crude oil into the ultrasonic demulsifier through the crude oil injection port using a certain pressurization method to maintain the pressure inside the tank within a certain range (e.g., 0.2-0.3 MPa, which can be set according to the test results to ultimately simulate a suitable temperature range).

[0016] Step 3: Turn on the electric heater and temperature transmitter of the ultrasonic demulsifier to keep the liquid temperature in the tank within a certain range (e.g., 70-80℃, which can be set according to the test results to finally simulate a suitable temperature range. A suitable temperature can reduce the viscosity of crude oil, dissolve the gums and asphaltenes in the crude oil, and at the same time increase the density difference between oil and water, so that the oil and water phases can be separated better). Step 4: Set the sound intensity, frequency and other parameters, turn on the power of the ultrasonic generator, and use it to oscillate and break the emulsion. Step 5: After acting for a period of time (30 min, 60 min, etc., depending on the demulsification effect observed by sampling), open the oil phase outlet valve and the electric demulsifier inlet valve to allow it to enter the electric demulsifier. Step 6: Continue to inject the target crude oil into the ultrasonic demulsification tank, and push all the demulsified crude oil into the electric demulsification tank. Repeat the steps 2 to 5. Step 7: After the electric de-oiling tank is full and pressurized, set the temperature parameters inside the tank, turn on the electric heater and temperature transmitter interlock to ensure that the liquid inside the tank is within a suitable temperature range. Step 8: Turn on the electric decanting pulse power supply, set the electric field parameters, and apply an electric field to the water-containing crude oil inside the electric decanting tank; Step 9: After a certain period of time, take a sample through the oil phase outlet to test its water content, and determine the test parameters based on the test results; Step 10: Repeat the above test process multiple times, continuously revising the parameters, to simulate suitable parameters that can process the target crude oil.

[0017] The beneficial effects of this invention are: 1. Through this test device, ultrasonic waves are applied to a large amount of aged oil circulating in the station to test suitable demulsification and dehydration parameters, reduce the effective volume occupied by aged oil in settling tanks, electric dehydrators and other dehydration equipment, and improve the utilization rate of crude oil dehydration equipment.

[0018] 2. The intermediate layer that is difficult to remove in the electric demulsifier can be returned to the ultrasonic demulsifier through the process pipeline for demulsification, and will no longer be discharged or mixed back. The properties of the oil will not deteriorate further, reducing the vicious cycle and ensuring the safe operation and dehydration and desalting effect of crude oil electric dehydration and desalting.

[0019] 3. This invention reduces the need for re-mixing, thus eliminating the need for increased dehydration temperature and dosage, thereby lowering the cost of dehydration and desalination.

[0020] 4. This invention enables the uniform dispersion of natural emulsifiers such as paraffin, colloids, and asphalt in crude oil media, increases their solubility, reduces the mechanical strength of the oil-water interface film, and facilitates the sedimentation and separation of the aqueous phase.

[0021] 5. This invention can simulate a set of dehydration and desalination parameters suitable for the target oil through a combination of dehydration tests such as ultrasonic, thermal sedimentation, thermochemical, and electro-dehydration, providing a scientific basis for industrial equipment. Attached Figure Description

[0022] Figure 1 This is a schematic diagram of the structure of the present invention; Figure 2 This is a schematic diagram of the ultrasonic demulsifying tank in this invention; Figure 3 In this invention Figure 2 Main sectional view; Figure 4 In this invention Figure 2 Top view; Figure 5 In this invention Figure 2 A bottom view; Figure 6 This is a schematic diagram of the structure of the electric decanter in this invention; Figure 7 In this invention Figure 6 Main sectional view; Figure 8 In this invention Figure 6 Top view; Figure 9 In this invention Figure 6 A bottom view.

[0023] The diagram shows: 1. Ultrasonic demulsifier, 2. Electric demulsifier, 3. Explosion-proof power control cabinet, 4. Water inlet for washing, 5. Inlet for injecting water-containing crude oil, 6. Aqueous phase outlet, 7. Qualified oil outlet, and 8. Electric heater. The ultrasonic demulsifying tank body is 100, the first water-containing crude oil inlet is 101, the first oil phase outlet is 102, the first water washing inlet / first sewage outlet is 103, the first anti-impact plate is 104, the first anti-vortex plate is 105, the ultrasonic generator is 106, the first temperature transmitter interface is 107, the first pressure transmitter interface is 108, the first electric heater interface is 109, the first viewing window is 1010, and the first support leg is 101. Desalination tank body 200, second water-containing crude oil inlet 201, second water washing inlet / second sewage outlet 203, second anti-impact plate 204, second anti-vortex plate 205, high pressure inlet 206, second temperature transmitter interface 207, second pressure transmitter interface 208, second electric heater interface 209, second viewing window 2010, second support leg 2011, insulator 2012, electrode plate 2013, zero pole orifice plate 2014; Detailed Implementation

[0024] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present invention.

[0025] Example 1 A combined acoustic-thermochemical and electrothermochemical dehydration experimental apparatus, such as Figure 1-9 As shown, it includes an ultrasonic demulsifying tank 1, an electric demulsifying tank 2, an explosion-proof power control cabinet 3, a water inlet 4, a water-containing crude oil inlet 5, an aqueous phase outlet 6, a qualified oil outlet 7, and an electric heater 8. The ultrasonic demulsifying tank 1 includes an ultrasonic demulsifying tank body 100. The lower part of the ultrasonic demulsifying tank body 100 is provided with a first water-containing crude oil inlet 101 and a first electric heater interface 109. The upper part of the ultrasonic demulsifying tank body 100 is provided with a first oil phase outlet 102. The bottom of the ultrasonic demulsifying tank body 100 is provided with a first water washing inlet (first wastewater outlet) 103. An ultrasonic generator 106 is inserted into the top of the ultrasonic demulsifying tank body 100, extending into the tank body. The top of the ultrasonic demulsifying tank body 100 is also provided with a first temperature transmitter interface 107 and a first pressure transmitter interface 108. The tank body corresponding to the first water-containing crude oil inlet 101 is provided with a first anti-impact plate 104. The tank body corresponding to the first water washing inlet (first sewage outlet) 103 is provided with a first anti-vortex plate 105. The pipe wall of the ultrasonic demulsifying tank body 100 is provided with two first viewing windows 1010. The bottom of the ultrasonic demulsifying tank body 100 is provided with a first support leg 1011.

[0026] The electrostatic dehydration tank 2 includes an electrostatic dehydration and desalination tank body 200. The lower part of the electrostatic dehydration and desalination tank body 200 is provided with a second water-containing crude oil inlet 201 and a second electric heater interface 209. The upper part of the electrostatic dehydration and desalination tank body 200 is provided with a second oil phase outlet 202. The bottom of the electrostatic dehydration and desalination tank body 200 is provided with a second water washing inlet (second wastewater outlet) 203. The top of the electrostatic dehydration and desalination tank body 200 is provided with a high-pressure inlet 206. The lower surface of the top of the electrostatic dehydration and desalination tank body 200 is connected to an electrode plate 2013 via an insulator 2012. The lower part of the electrode plate 2013 is provided with a zero electrode orifice plate 2014 on the tank wall. The top of the electric dehydration and desalination tank body 200 is also provided with a second temperature transmitter interface 207 and a second pressure transmitter interface 208. The tank body corresponding to the second water-containing crude oil inlet 201 is provided with a second anti-impact plate 204. The tank body corresponding to the second water washing inlet (second sewage outlet) 203 is provided with a second anti-vortex plate 205. The pipe wall of the electric dehydration and desalination tank body 200 is provided with two second viewing windows 2010. The bottom of the electric dehydration and desalination tank body 200 is provided with a second support leg 2011.

[0027] The first water-containing crude oil inlet 101 is connected to the water-containing crude oil injection port 5 via a pipeline; the first water washing inlet (first sewage outlet) 103 and the second water washing inlet (second sewage outlet) 203 are connected to the water washing inlet 4 and the water phase outlet 6 via pipelines; the first oil phase outlet 102 is connected to the second water-containing crude oil inlet 201 via a pipeline; the second oil phase outlet 202 is connected to the qualified oil outlet 7 via a pipeline; the second oil phase outlet 202 is connected to the first water-containing crude oil inlet 101 and the second water-containing crude oil inlet 201 via pipelines.

[0028] The explosion-proof power control cabinet 3 consists of a power control system, a PLC control system, a display screen, a pressure display and recording module (PR), a temperature display and recording control module (TRC), a temperature alarm interlock module (TAS), a pulse power control module (PSU), and an explosion-proof cabinet shell.

[0029] An electric heater 8 is connected to the first electric heater interface 109 and the second electric heater interface 209, and the electric heater 8 is connected to the explosion-proof power control cabinet 3 via a line; the first temperature transmitter interface 107 and the second temperature transmitter interface 207 are connected to the explosion-proof power control cabinet 3 via a line; the first pressure transmitter interface 108 and the second pressure transmitter interface 208 are connected to the explosion-proof power control cabinet 3 via a line; the ultrasonic generator 106 and the high-pressure inlet 206 are connected to the explosion-proof power control cabinet 3 via a line.

[0030] Example 2 A combined acoustic-thermochemical and electrothermochemical dehydration experimental method, such as Figure 1 As shown, it includes the following steps: Step 1: Inject an appropriate amount of clean water into the ultrasonic demulsifying tank and the electric demulsifying tank through the water inlet, ensuring that the water level exceeds the inlet height of the water-containing crude oil but does not exceed the electric heater. This will wash the injected crude oil, causing the oil-water interface film of some oil-in-water (O / W) particles in the oil-water mixture to break down, thereby dissolving a large number of water molecules, acid and alkali ions, and mineral salts in the free water, which will be discharged with the wash water.

[0031] Step 2: After the water wash is injected, close the crude oil outlet valve of the ultrasonic demulsifier. Inject the target crude oil into the ultrasonic demulsifier through the crude oil injection port using a certain pressurization method to maintain the pressure inside the tank within a certain range (e.g., 0.2-0.3 MPa, which can be set according to the test results to ultimately simulate a suitable temperature range).

[0032] Step 3: Turn on the electric heater and temperature transmitter of the ultrasonic demulsifier to keep the liquid temperature in the tank within a certain range (e.g., 70-80℃, which can be set according to the test results to finally simulate a suitable temperature range. A suitable temperature can reduce the viscosity of crude oil, dissolve the gums and asphaltenes in the crude oil, and at the same time increase the density difference between oil and water, so that the oil and water phases can be separated better). Step 4: Set the sound intensity, frequency and other parameters, turn on the power of the ultrasonic generator, and use it to oscillate and break the emulsion. Step 5: After acting for a period of time (30 min, 60 min, etc., depending on the demulsification effect observed by sampling), open the oil phase outlet valve and the electric demulsifier inlet valve to allow it to enter the electric demulsifier. Step 6: Continue to inject the target crude oil into the ultrasonic demulsification tank, and push all the demulsified crude oil into the electric demulsification tank. Repeat the steps 2 to 5. Step 7: After the electric de-oiling tank is full and pressurized, set the temperature parameters inside the tank, turn on the electric heater and temperature transmitter interlock to ensure that the liquid inside the tank is within a suitable temperature range. Step 8: Turn on the electric decanting pulse power supply, set the electric field parameters, and apply an electric field to the water-containing crude oil inside the electric decanting tank; Step 9: After a certain period of time, take a sample through the oil phase outlet to test its water content, and determine the test parameters based on the test results; Step 10: Repeat the above test process multiple times, continuously revising the parameters, to simulate suitable parameters that can process the target crude oil.

[0033] Example 3 Working Principle 1. Working principle of ultrasonic crude oil dehydration Ultrasonic crude oil dehydration achieves oil-water separation based on the "displacement effect" generated by ultrasound acting on fluid media with different properties. Due to the "displacement effect," water ions continuously move towards antinodes or nodes, aggregate, and collide, generating larger water droplets, which then separate from the oil under the influence of gravity. Ultrasonic crude oil dehydration mainly utilizes the mechanical vibration and thermal effects of ultrasound.

[0034] 1. Mechanical vibration promotes the coagulation of water particles. When ultrasound passes through crude oil containing suspended water particles, the suspended water particles vibrate along with the crude oil medium. Because suspended water particles of different sizes have different relative vibration velocities, the water particles will collide and adhere to each other, increasing the volume and mass of the particles, and eventually settling and separating.

[0035] 2. Mechanical vibration can make natural emulsifiers such as paraffin, gum, and asphalt in crude oil media disperse evenly, increase their solubility, reduce the mechanical strength of the oil-water interface film, and facilitate the sedimentation and separation of the aqueous phase.

[0036] 3. Thermal effects can reduce the strength of the oil-water interface film and the viscosity of crude oil. On the one hand, boundary friction raises the temperature at the oil-water interface, which is conducive to the rupture of the interface film; on the other hand, the crude oil absorbs some of the sound energy and converts it into heat energy, which can reduce the viscosity of the crude oil and facilitate the gravity sedimentation and separation of water particles.

[0037] 2. Factors affecting ultrasonic demulsification Many factors influence ultrasonic demulsification, such as sound intensity, ultrasonic frequency, radiation time, temperature, settling time, and crude oil viscosity.

[0038] 1) Sound intensity and its distribution are important factors affecting ultrasonic demulsification. Due to the significant differences in the properties of various crude oils, the optimal sound intensity required for demulsification varies.

[0039] 2) Within a certain range, the frequency of the wave only affects the distance that the "particles" travel towards the antinodes or nodes, and its effect on the demulsification effect is not very significant within a certain range. The optimal frequency for particles to condense under the action of sound waves is approximately within the range of 20 to 25 kHz.

[0040] 3) Emulsification and demulsification are actually a dynamic equilibrium process. Choosing an appropriate treatment time can demulsify the emulsion, but if the ultrasonic treatment time is too long, it may emulsify the separated oil and water phases, forming a more stable emulsion. Therefore, longer ultrasonic radiation time is not necessarily better.

[0041] 3. Principle of heated sedimentation dewatering process Oil well products are heated to increase the temperature, which reduces the viscosity of crude oil and increases the density difference between oil and water. Through gravity sedimentation, the water-containing crude oil is separated by sedimentation in a settling tank to form an oil-water interface, which is then discharged through different outlets, achieving the effect of separating free water from crude oil.

[0042] In order to achieve the effect of sedimentation and dehydration of crude oil, the crude oil is heated before entering the sedimentation tank to raise the temperature of the oil flow and accelerate the molecular motion speed. By relying on the density difference between oil and water, the dehydration purpose is achieved through a certain residence time in the sedimentation tank.

[0043] 4. Optimization of chemical dehydration process technology The key to chemical dehydration is selecting the optimal chemical demulsifier to break the emulsion, reduce the strength of the oil-water interface, separate the emulsion water, and achieve crude oil dehydration. It is best to use a demulsifier that operates at low temperatures to achieve demulsification and dehydration. The better the demulsifier, the higher the crude oil dehydration efficiency. When selecting a chemical demulsifier, it is necessary to use a product with good demulsification effect and low price to meet the technical requirements of energy conservation and emission reduction in oilfield production.

[0044] 5. Electro-dehydration technology Electrostatic desalting and dehydration refers to a process technology that involves placing a crude oil emulsion in a high-voltage AC or DC electric field. Under the influence of the electric field, the strength of the water droplet interfacial film is weakened, promoting collisions between water droplets and causing them to coalesce and settle, thereby removing the emulsified water from the crude oil. Under the influence of the electric field, charged water droplets achieve separation through electrophoretic coalescence, dipole coalescence, and oscillatory coalescence.

[0045] It will be apparent to those skilled in the art that the present invention is not limited to the details of the exemplary embodiments described above, and that the invention can be implemented in other specific forms without departing from its spirit or essential characteristics. Therefore, the embodiments should be considered in all respects as exemplary and non-limiting, and the scope of the invention is defined by the appended claims rather than the foregoing description. Thus, all variations falling within the meaning and scope of equivalents of the claims are intended to be included within the present invention. No reference numerals in the claims should be construed as limiting the scope of the claims.

Claims

1. A combined acoustic-thermochemical and electrothermochemical dehydration experimental apparatus, characterized in that, Includes an ultrasonic demulsifier (1), an electric demulsifier (2), an explosion-proof power control cabinet (3), a water inlet (4), a water-containing crude oil inlet (5), an aqueous phase outlet (6), a qualified oil outlet (7), and an electric heater (8). The ultrasonic demulsifying tank (1) includes an ultrasonic demulsifying tank body (100). The lower part of the ultrasonic demulsifying tank body (100) is provided with a first water-containing crude oil inlet (101) and a first electric heater interface (109). The upper part of the ultrasonic demulsifying tank body (100) is provided with a first oil phase outlet (102). The bottom of the ultrasonic demulsifying tank body (100) is provided with a first water washing inlet / first sewage outlet (103). An ultrasonic generator (106) extending into the tank body is inserted at the top of the ultrasonic demulsifying tank body (100). The top of the ultrasonic demulsifying tank body (100) is also provided with a first temperature transmitter interface (107) and a first pressure transmitter interface (108). The electrostatic dehydration tank (2) includes an electrostatic dehydration and desalination tank body (200). The lower part of the electrostatic dehydration and desalination tank body (200) is provided with a second water-containing crude oil inlet (201) and a second electric heater interface (209). The upper part of the electrostatic dehydration and desalination tank body (200) is provided with a second oil phase outlet (202). The bottom of the electrostatic dehydration and desalination tank body (200) is provided with a second water washing inlet / second wastewater outlet (203). The top of the salt tank body (200) is provided with a high pressure inlet (206). The lower surface of the top of the electric dehydration and desalination tank body (200) is connected to an electrode plate (2013) through an insulator (2012). The tank wall below the electrode plate (2013) is provided with a zero electrode orifice plate (2014). The top of the electric dehydration and desalination tank body (200) is also provided with a second temperature transmitter interface (207) and a second pressure transmitter interface (208).

2. The acoustic-thermochemical and electrothermochemical combined dehydration experimental apparatus according to claim 1, characterized in that, The tank corresponding to the first water-containing crude oil inlet (101) is provided with a first anti-impact plate (104), the tank corresponding to the first water washing inlet / first sewage outlet (103) is provided with a first anti-vortex plate (105), the ultrasonic demulsifying tank body (100) is provided with two first viewing windows (1010) on the pipe wall, and the bottom of the ultrasonic demulsifying tank body (100) is provided with a first support leg (1011).

3. The acoustic-thermochemical and electrothermochemical combined dehydration experimental apparatus according to claim 2, characterized in that, The tank corresponding to the second water-containing crude oil inlet (201) is provided with a second anti-impact plate (204), the tank corresponding to the second water washing inlet / second sewage outlet (203) is provided with a second anti-vortex plate (105), the pipe wall of the electric dehydration and desalination tank (200) is provided with two second viewing windows (2010), and the bottom of the electric dehydration and desalination tank (200) is provided with a second support leg (2011).

4. The acoustic-thermochemical and electrothermochemical combined dehydration experimental apparatus according to claim 3, characterized in that, The first water-containing crude oil inlet (101) is connected to the water-containing crude oil injection port (5) via a pipeline; the first water washing inlet / first sewage outlet (103) and the second water washing inlet / second sewage outlet (203) are connected to the water washing inlet (4) and the water phase outlet (6) via pipelines; the first oil phase outlet (102) is connected to the second water-containing crude oil inlet (201) via a pipeline; the second oil phase outlet (202) is connected to the qualified oil outlet (7) via a pipeline; the second oil phase outlet (202) is connected to the first water-containing crude oil inlet (101) and the second water-containing crude oil inlet (201) via a pipeline.

5. The acoustic-thermochemical and electrothermochemical combined dehydration experimental apparatus according to claim 4, characterized in that, An electric heater (8) is connected to the first electric heater interface (109) and the second electric heater interface (209), and the electric heater (8) is connected to the explosion-proof power control cabinet (3) through a line; the first temperature transmitter interface (107) and the second temperature transmitter interface (207) are connected to the explosion-proof power control cabinet (3) through a line; the first pressure transmitter interface (108) and the second pressure transmitter interface (208) are connected to the explosion-proof power control cabinet (3) through a line; the ultrasonic generator (106) and the high-pressure inlet (206) are connected to the explosion-proof power control cabinet (3) through a line.

6. The acoustic-thermochemical and electrothermochemical combined dehydration experimental apparatus according to claim 5, characterized in that, The explosion-proof power control cabinet (3) consists of a power control system, a PLC control system, a display screen, a pressure display and recording module (PR), a temperature display and recording control module (TRC), a temperature alarm interlock module (TAS), a pulse power control module (PSU), and an explosion-proof cabinet shell.

7. A combined acoustic-thermochemical and electrothermochemical dehydration experimental method, characterized in that, Includes the following steps: Step 1: Inject an appropriate amount of clean water into the ultrasonic demulsifying tank and the electric demulsifying tank through the water inlet, ensuring that the water level exceeds the inlet height of the water-containing crude oil but does not exceed the height of the electric heater. Step 2: After the water wash is injected, close the crude oil outlet valve of the ultrasonic demulsifier. Inject the target crude oil into the ultrasonic demulsifier through the crude oil injection port using a certain pressurization method to maintain the pressure inside the tank within the specified range. Step 3: Turn on the electric heater and temperature transmitter interlock control of the ultrasonic demulsifier to keep the liquid temperature in the tank within the specified range. Step 4: Set the sound intensity and frequency parameters, turn on the power of the ultrasonic generator, and use it to oscillate and break the emulsion. Step 5: After the specified time has elapsed, open the oil phase outlet valve and the electric descrambling tank inlet valve to allow the oil phase to enter the electric descrambling tank. Step 6: Continue to inject the target crude oil into the ultrasonic demulsification tank, and push all the demulsified crude oil into the electric demulsification tank. Repeat the steps 2 to 5. Step 7: After the electric de-oiling tank is full and pressurized, set the temperature parameters inside the tank, turn on the electric heater and temperature transmitter interlock to ensure that the liquid inside the tank is within the specified temperature range. Step 8: Turn on the electric decanting pulse power supply, set the electric field parameters, and apply an electric field to the water-containing crude oil inside the electric decanting tank; Step 9: After the specified time has elapsed, take a sample through the oil phase outlet to test its water content, and determine the test parameters based on the test results; Step 10: Repeat the above test process multiple times, continuously revising the parameters, to simulate suitable parameters that can process the target crude oil.

8. The combined acoustic-thermochemical and electrothermochemical dehydration experimental method according to claim 7, characterized in that, In step two, the pressure range is 0.2 to 0.3 MPa.

9. The combined acoustic-thermochemical and electrothermochemical dehydration experimental method according to claim 7, characterized in that, In steps three and seven, the temperature range is 70–80°C.

10. The combined acoustic-thermochemical and electrothermochemical dehydration experimental method according to claim 7, characterized in that, In steps five and nine, the specified time is 30 minutes or 60 minutes.

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