A device and method for testing low-temperature dynamic emulsification water cut of high water cut crude oil

Abstract

The application provides a high-water-content crude oil low-temperature dynamic emulsion water content testing device and method, which comprises a dynamic emulsion preparation structure, a preparation tank and a stirring mechanism arranged in the preparation tank, a temperature control assembly arranged outside the preparation tank, a stirring control unit connected with the stirring mechanism, and a stirring control unit used for controlling the rotating speed of the stirring mechanism according to the properties of the crude oil; a measuring structure comprising a metering container connected with the preparation tank, a metering and collecting assembly arranged on one side of the metering container, and a metering and collecting assembly used for collecting the oil-water separation interface data in the metering container at a fixed time; a processing unit connected with the temperature control assembly and the metering and collecting assembly, used for controlling the operation of the temperature control assembly and calculating the emulsified water content of the crude oil according to the data collected by the metering and collecting assembly; and the high-water-content crude oil low-temperature dynamic emulsion is prepared by simulating the actual temperature and flow condition of the unheated gathering pipeline through the dynamic emulsion preparation structure, so that the authenticity of the test is improved.

Description

Technical Field

[0001] This invention belongs to the field of multiphase flow oil and gas field gathering and transportation technology, and more specifically, relates to a device and method for testing the water content of high water content crude oil under low temperature dynamic emulsification. Background Technology

[0002] As oilfield development enters its mid-to-late stages, the overall water cut of produced fluids gradually rises to a high water cut level. To reduce the significant energy consumption of traditional surface gathering and transportation methods, most older oilfields are gradually adopting unheated gathering and transportation. Research has shown that even with unheated gathering and transportation, where the inlet temperature is lowered below the pour point, oil products can still be safely transported. Under high water cut and low temperature conditions, as the emulsified water cut of crude oil increases before the phase reversal point, the viscosity of the medium system inside the gathering and transportation pipeline significantly increases, hindering the surface gathering and transportation process of produced fluids from the wellhead. Therefore, developing and formulating measurement devices and methods for the low-temperature dynamic emulsified water cut of high water cut crude oil is beneficial for further deepening the optimization research of surface gathering and transportation systems.

[0003] Currently, research on crude oil emulsification characteristics by domestic and international research institutions and scholars mainly focuses on the emulsification characteristics of crude oil under high-temperature conditions (10℃~20℃ above the pour point) and a comprehensive water content below 70%. This is primarily applicable to measuring the water content of crude oil emulsions transported under heated conditions in traditional gathering and transportation modes. For example, in 2014, China University of Petroleum (Beijing) proposed a test method for the emulsification characteristics of an oil-water two-phase system under flow conditions. This method mainly targets the emulsification characteristics of crude oil under high-temperature, low-water-content flow conditions. The basic principle is as follows: First, crude oil and aqueous solution are placed in a stirring device, and actual pipeline transportation is simulated at different temperatures and rotation speeds; then, the optimal temperature and rotation speed matching is compared, and the apparent viscosity of the actual transported medium in the pipeline is calculated; finally, the optimal heating and gathering temperature and flow rate are obtained.

[0004] For high-water-content, unheated gathering and transportation modes, the traditional crude oil emulsification characteristic testing methods described above are no longer sufficient to meet the needs of practical engineering problems. Furthermore, traditional methods for determining the water content of crude oil emulsions are complex, have low equipment efficiency, and do not meet current research requirements. Therefore, while ensuring efficiency and scientific rigor, it is necessary to develop a low-temperature dynamic emulsification water content testing device and method for high-water-content crude oil with a water content of 70%–95% and a temperature range of 5°C above the pour point to 10°C below the pour point. Summary of the Invention

[0005] The purpose of this invention is to address the shortcomings of existing technologies by providing a device and method for testing the low-temperature dynamic emulsion water content of high-water-content crude oil. This device prepares a low-temperature dynamic emulsion of high-water-content crude oil by simulating the actual temperature and flow conditions of an unheated gathering and transportation pipeline through a dynamic emulsion preparation structure. It automatically calculates the low-temperature dynamic emulsion water content of high-water-content crude oil under different temperatures, stirring speeds, and overall water content based on the measurement results of the measurement structure, providing a theoretical basis for determining the pressure drop boundary conditions of unheated gathering and transportation pipelines.

[0006] To achieve the above objectives, the present invention provides a low-temperature dynamic emulsification water content testing device for high water content crude oil, the device comprising:

[0007] A dynamic emulsion preparation structure includes a preparation tank and a stirring mechanism disposed inside the preparation tank. A temperature control component is disposed on the outside of the preparation tank. The stirring mechanism is connected to a stirring control unit, which is used to control the rotation speed of the stirring mechanism according to the properties of the crude oil.

[0008] The measuring structure includes a metering container connected to the preparation tank, and a metering acquisition component is provided on one side of the metering container. The metering acquisition component is used to periodically collect oil-water separation interface data in the metering container.

[0009] The processing unit is connected to the temperature control component and the metering and acquisition component, and is used to control the operation of the temperature control component and calculate the crude oil emulsified water content based on the data collected by the metering and acquisition component.

[0010] Optionally, the temperature control component includes:

[0011] A temperature-controlled water jacket is wrapped around the outside of the preparation tank, and the temperature-controlled water jacket is provided with a water jacket inlet and a water jacket outlet;

[0012] A temperature-controlled water bath is connected to the water jacket inlet and the water jacket outlet via a first pipeline and a second pipeline, respectively.

[0013] Optionally, the bottom of the preparation tank is provided with a liquid outlet, and an electrically controlled valve is provided inside the liquid outlet.

[0014] Optionally, the stirring mechanism includes a stirring motor, a stirring shaft, stirring blades, a speed monitoring sensor, and a stirring shaft torque monitoring sensor.

[0015] Optionally, the processing unit includes a viscosity calculation module, which is used to calculate the viscosity of the emulsion based on the measurement results of the stirring shaft torque monitoring sensor and the rotation speed monitoring sensor.

[0016] This invention also provides a method for testing the low-temperature dynamic emulsification water content of high-water-content crude oil, utilizing the aforementioned device for testing the low-temperature dynamic emulsification water content of high-water-content crude oil. The method includes:

[0017] Prepare an emulsion of crude oil and water at a set temperature;

[0018] The prepared emulsion is injected into a metering container, and the oil-water separation interface data in the metering container is collected periodically by a metering acquisition component.

[0019] The crude oil emulsified water content is calculated based on the oil-water separation interface data collected periodically by the metering acquisition component within the metering container.

[0020] Optionally, the preparation of the crude oil and water emulsion at a set temperature includes injecting crude oil and water into a preparation tank in a set ratio, and stirring the crude oil and water with a stirring mechanism to form the emulsion.

[0021] Optionally, after the emulsion is prepared, the rotational speed and torque of the stirring shaft of the stirring mechanism are measured, and the viscosity of the emulsion is calculated based on the rotational speed and the torque.

[0022] Optionally, calculating the viscosity of the emulsion based on the rotational speed and the torque includes calculating the viscosity of the emulsion using the following formula:

[0023] μ=aM b

[0024] Where μ is the viscosity of the emulsion; a and b are fitting parameters; and M is the torque.

[0025] Optionally, the step of calculating the crude oil emulsified water content based on the oil-water separation interface data collected periodically by the metering acquisition component within the metering container includes:

[0026] The cumulative volume of water separated from the emulsion after a set time is calculated using the following formula:

[0027] V f =kln(t+m)+n

[0028] Among them, V f The cumulative volume of water separated from the emulsion after a set time; t is the set time; k, m, and n are fitting parameters;

[0029] The emulsified water content of the crude oil is calculated using the following formula:

[0030]

[0031] Among them, V m V is the total volume of the emulsion;w V is the volume of the aqueous phase in the emulsion; f0 The cumulative volume of water separated from the emulsion at t=0.

[0032] This invention provides a device and method for testing the water content of high-water-content crude oil under low-temperature dynamic emulsification, the advantages of which are:

[0033] 1. A low-temperature dynamic emulsion of crude oil with high water content was prepared by simulating the actual temperature and flow conditions of an unheated gathering and transportation pipeline through a dynamic emulsion preparation structure. The test temperature and stirring speed can be controlled by the temperature control component and the stirring control unit, thereby improving the authenticity of the test.

[0034] 2. The processing unit can automatically calculate the low-temperature dynamic emulsification water content of high water content crude oil under different temperatures, stirring speeds and overall water content based on the measurement results of the measuring structure. This facilitates the investigation of the influence of different temperatures, stirring speeds and overall water content on the low-temperature dynamic emulsification water content of high water content crude oil, and provides a theoretical basis for determining the pressure drop boundary conditions of unheated gathering and transportation pipelines.

[0035] 3. The viscosity of the emulsion can be calculated based on the measurement results of the stirring shaft torque monitoring sensor and the speed monitoring sensor. This facilitates the investigation of the relationship between the water content of the low-temperature dynamic emulsification of high water content crude oil and the viscosity of the emulsion. It is also beneficial for calculating the pressure drop of unheated gathering and transportation pipelines under low-temperature conditions. This allows for unheated gathering and transportation on the basis of safe operation, reducing the energy consumption of the gathering and transportation system and improving the actual production efficiency of the oilfield.

[0036] Other features and advantages of the present invention will be described in detail in the following detailed description section. Attached Figure Description

[0037] The above and other objects, features and advantages of the present invention will become more apparent from the more detailed description of exemplary embodiments of the invention in conjunction with the accompanying drawings, wherein the same reference numerals generally represent the same components in the exemplary embodiments of the invention.

[0038] Figure 1 A schematic diagram of a low-temperature dynamic emulsification water content testing device for high water content crude oil according to Embodiment 1 of the present invention is shown.

[0039] Figure 2 A flowchart of a method for testing the water content of high-water-content crude oil under low-temperature dynamic emulsification according to Embodiment 2 of the present invention is shown.

[0040] Figure 3 The diagram shows crude oil emulsified water content curves under different temperature conditions, measured by a low-temperature dynamic emulsification water content testing device for high water content crude oil according to Embodiment 1 of the present invention.

[0041] Explanation of reference numerals in the attached figures:

[0042] 1. Preparation tank; 2. Stirring mechanism; 3. Temperature control component; 4. Stirring control unit; 5. Metering container; 6. Metering acquisition component; 7. Processing unit; 8. Temperature-controlled water jacket; 9. Temperature-controlled water bath; 10. First pipeline; 11. Second pipeline; 12. Electrically controlled valve; 13. Stirring motor; 14. Stirring shaft; 15. Stirring blade. Detailed Implementation

[0043] Preferred embodiments of the invention will now be described in more detail. While preferred embodiments of the invention are described below, it should be understood that the invention can be implemented in various forms and should not be limited to the embodiments set forth herein. Rather, these embodiments are provided so that the invention will be thorough and complete, and will fully convey the scope of the invention to those skilled in the art.

[0044] This invention provides a device for testing the low-temperature dynamic emulsification water content of high-water-content crude oil, the device comprising:

[0045] The dynamic emulsion preparation structure includes a preparation tank and a stirring mechanism installed inside the preparation tank. A temperature control component is installed on the outside of the preparation tank. The stirring mechanism is connected to a stirring control unit, which is used to control the rotation speed of the stirring mechanism according to the properties of the crude oil.

[0046] The measuring structure includes a metering container connected to the preparation tank. A metering acquisition component is provided on one side of the metering container. The metering acquisition component is used to periodically collect oil-water separation interface data inside the metering container.

[0047] The processing unit, connected to the temperature control component and the metering and acquisition component, is used to control the operation of the temperature control component and calculate the crude oil emulsified water content based on the data collected by the metering and acquisition component.

[0048] Specifically, a certain proportion of crude oil and water is injected into the preparation tank. The temperature inside the preparation tank can be adjusted by the temperature control component. The crude oil and water are stirred by the stirring mechanism to form a mixed emulsion. By changing the ratio of crude oil to water and changing the temperature, emulsions with different overall water content and emulsions at different temperatures can be prepared. After the emulsion is prepared, it can be injected into the metering container. The oil-water separation interface data in the metering container can be collected at regular intervals by the metering acquisition component. Then, the volume of water precipitated from the emulsion in the metering container after a set time can be calculated. Then, the processing unit can calculate the crude oil emulsion water content based on the volume of precipitated water.

[0049] In one example, the measuring container is equipped with volume scales, and the measuring acquisition components include a high-speed camera.

[0050] Specifically, the high-speed camera can capture images of the volume scale corresponding to the oil-water separation interface inside the metering container.

[0051] Optionally, the temperature control component includes:

[0052] A temperature-controlled water jacket is wrapped around the outside of the preparation tank. The temperature-controlled water jacket is equipped with a water jacket inlet and a water jacket outlet.

[0053] The temperature-controlled water bath is connected to the water jacket inlet and outlet via the first pipeline and the second pipeline, respectively.

[0054] Specifically, the temperature-controlled water bath includes a water storage container, a heating element, and a cooling element. The heating element and the cooling element can heat and cool the water in the water storage container, respectively. The temperature of the preparation tank is controlled by pouring water into the temperature-controlled water jacket. In one example, a pump is installed on the first pipeline and / or the second pipeline.

[0055] Optionally, the bottom of the preparation tank is provided with a liquid outlet, and an electrically controlled valve is installed inside the liquid outlet.

[0056] Specifically, the preparation tank is connected to the metering container through the liquid outlet. After the electrically controlled valve is opened, the emulsion in the preparation tank can flow into the metering container.

[0057] Optionally, the stirring mechanism includes a stirring motor, a stirring shaft, stirring blades, a speed monitoring sensor, and a stirring shaft torque monitoring sensor.

[0058] Specifically, the speed monitoring sensor and the stirring shaft torque monitoring sensor are used to monitor the stirring speed and torque, respectively.

[0059] Optionally, the processing unit includes a viscosity calculation module, which is used to calculate the viscosity of the emulsion based on the measurement results of the stirring shaft torque monitoring sensor and the rotation speed monitoring sensor.

[0060] Specifically, the speed and torque of the stirring shaft monitored by the speed monitoring sensor and the stirring shaft torque monitoring sensor are uploaded to the viscosity calculation module in the processing unit. The viscosity calculation module can calculate the viscosity of the oil-water emulsion according to the corresponding formula.

[0061] Optionally, it also includes a scaffold, on which the dynamic emulsion preparation structure and the measurement structure are disposed.

[0062] This invention also provides a method for testing the low-temperature dynamic emulsification water content of high-water-content crude oil, utilizing the aforementioned device for testing the low-temperature dynamic emulsification water content of high-water-content crude oil. The method includes:

[0063] Prepare an emulsion of crude oil and water at a set temperature;

[0064] The prepared emulsion is injected into a metering container, and the oil-water separation interface data in the metering container is collected periodically by a metering acquisition component.

[0065] The crude oil emulsified water content is calculated based on the oil-water separation interface data collected periodically by the metering acquisition component within the metering container.

[0066] Specifically, the aforementioned dynamic emulsion preparation structure can be used to prepare an emulsion formed by mixing crude oil and water at a set temperature and in a test ratio. After the prepared emulsion is injected into the metering container, it will separate into layers within the metering container over time, forming an oil-water separation interface. The metering acquisition component uses a high-speed camera to capture images of the corresponding positions of the oil-water separation interface and the volume scale on the metering container, and uploads them to the processing unit. The processing unit can then calculate the crude oil emulsion water content based on these images.

[0067] Optionally, preparing an emulsion of crude oil and water at a set temperature includes injecting crude oil and water into a preparation tank in a set ratio and stirring the crude oil and water to form an emulsion using a stirring mechanism.

[0068] Specifically, users can set the temperature and the ratio of crude oil to water as needed to prepare a low-temperature dynamic emulsion of crude oil with high water content in the preparation tank.

[0069] Optionally, after the emulsion is prepared, the rotational speed and torque of the stirring shaft of the stirring mechanism are measured, and the viscosity of the emulsion is calculated based on the rotational speed and torque.

[0070] Optionally, calculating the viscosity of the emulsion based on the rotational speed and torque includes calculating the viscosity of the emulsion using the following formula:

[0071] μ=aM b

[0072] Where μ is the viscosity of the emulsion; a and b are fitting parameters; and M is torque.

[0073] Specifically, firstly, the oil-water mixture is stirred at different speeds, and the torque value of the stirring mechanism is measured. Then, the effective viscosity of the oil-water mixture at the corresponding speed is calculated using the following formula:

[0074] In a stirred flow field, at a certain rotational speed, the viscosity of the emulsion and the stirring torque have the following relationship:

[0075] μ=aM b

[0076] Where μ is the viscosity of the emulsion; a and b are fitting parameters; and M is torque.

[0077] Subsequently, based on the method derived from the relationship between energy dissipation rate and shear rate, the formula for calculating the average shear rate inside the preparation tank was derived:

[0078]

[0079] Where μ is the emulsion viscosity; N is the rotational speed of the stirring mechanism; and c, d, and e are fitting parameters.

[0080] Optionally, the calculation of crude oil emulsified water content based on the oil-water separation interface data collected periodically by the metering acquisition component within the metering container includes:

[0081] The cumulative volume of water separated from the emulsion after a set time is calculated using the following formula:

[0082] V f =k ln(t+m)+n

[0083] Among them, V f The cumulative volume of water separated from the emulsion after a set time; t is the set time; k, m, and n are the fitting parameters;

[0084] The emulsified water content of crude oil is calculated using the following formula:

[0085]

[0086] Among them, V m V is the total volume of the emulsion; w V is the volume of the aqueous phase in the emulsion; f0 This represents the cumulative volume of water separated from the emulsion at t=0.

[0087] Specifically, the values ​​of k, m, and n have been obtained through extensive experiments on crude oil from different high water-cut oilfields in China.

[0088] Example 1

[0089] like Figure 1 As shown, the present invention provides a low-temperature dynamic emulsification water content testing device for high water content crude oil, the device comprising:

[0090] The dynamic emulsion preparation structure includes a preparation tank 1 and a stirring mechanism 2 installed inside the preparation tank 1. A temperature control component 3 is installed on the outside of the preparation tank 1. The stirring mechanism 2 is connected to a stirring control unit 4, which is used to control the rotation speed of the stirring mechanism 2 according to the properties of the crude oil.

[0091] The measuring structure includes a metering container 5 connected to the preparation tank 1. A metering acquisition component 6 is provided on one side of the metering container 5. The metering acquisition component 6 is used to periodically collect oil-water separation interface data in the metering container 5.

[0092] The processing unit 7 is connected to the temperature control component 3 and the metering and acquisition component 6. It is used to control the operation of the temperature control component 3 and calculate the crude oil emulsified water content based on the data collected by the metering and acquisition component 6.

[0093] In this embodiment, the temperature control component 3 includes:

[0094] Temperature control water jacket 8 is wrapped around the outside of preparation tank 1. Temperature control water jacket 8 is provided with water jacket inlet and water jacket outlet.

[0095] The temperature-controlled water bath 9 is connected to the water jacket inlet and water jacket outlet through the first pipeline 10 and the second pipeline 11, respectively.

[0096] In this embodiment, the bottom of the preparation tank 1 is provided with a liquid outlet, and an electrically controlled valve 12 is provided inside the liquid outlet.

[0097] In this embodiment, the stirring mechanism 2 includes a stirring motor 13, a stirring shaft 14, stirring blades 15, a speed monitoring sensor, and a stirring shaft torque monitoring sensor.

[0098] In this embodiment, the processing unit 7 includes a viscosity calculation module, which is used to calculate the viscosity of the emulsion based on the measurement results of the stirring shaft torque monitoring sensor and the rotation speed monitoring sensor.

[0099] In summary, when using the high water content crude oil low-temperature dynamic emulsification water content testing device provided by this invention, taking a single test as an example, the testing steps are as follows:

[0100] (1) The test crude oil and water are injected into the preparation tank 1 according to the test ratio. The temperature control component 3 keeps the preparation tank 1 at the test temperature for more than 10 minutes to keep its internal temperature field constant.

[0101] (2) Set the preset script speed of the stirring mechanism 2 in the stirring control unit 4, start the stirring mechanism 2, and stir the oil-water mixture. The torque during the stirring process is uploaded and recorded in the processing unit in real time.

[0102] (3) After stirring stops, the processing unit controls the electronically controlled valve 12 to open automatically, injecting the emulsion formed by stirring the oil-water mixture into the metering container 5. The oil-water separation interface in the metering container 5 is collected by a high-speed camera and uploaded to the processing unit 7. The processing unit 7 analyzes the oil-water interface, records the change in the amount of water separated in the oil-water mixture over time, performs background calculations, and finally outputs the test results of the low-temperature dynamic emulsification water content of high water content crude oil.

[0103] (4) Repeat steps (1) to (3) to perform three repeated tests. Take the average of the three tests as the final result to provide the accuracy of the test.

[0104] Example 2

[0105] like Figure 2 As shown, the present invention also provides a method for testing the low-temperature dynamic emulsified water content of high-water-content crude oil, utilizing the aforementioned device for testing the low-temperature dynamic emulsified water content of high-water-content crude oil. The method includes:

[0106] Prepare an emulsion of crude oil and water at a set temperature;

[0107] The prepared emulsion is injected into a metering container, and the oil-water separation interface data in the metering container is collected periodically by a metering acquisition component.

[0108] The crude oil emulsified water content is calculated based on the oil-water separation interface data collected periodically by the metering acquisition component within the metering container.

[0109] In this embodiment, preparing an emulsion of crude oil and water at a set temperature includes injecting crude oil and water into a preparation tank in a set ratio, and stirring the crude oil and water with a stirring mechanism to form an emulsion.

[0110] In this embodiment, after the emulsion is prepared, the rotational speed and torque of the stirring shaft of the stirring mechanism are measured, and the viscosity of the emulsion is calculated based on the rotational speed and torque.

[0111] In this embodiment, calculating the viscosity of the emulsion based on the rotational speed and torque includes calculating the viscosity of the emulsion using the following formula:

[0112] μ=aM b

[0113] Where μ is the viscosity of the emulsion; a and b are fitting parameters; and M is torque.

[0114] In this embodiment, calculating the crude oil emulsified water content based on the oil-water separation interface data collected periodically by the metering acquisition component within the metering container includes:

[0115] The cumulative volume of water separated from the emulsion after a set time is calculated using the following formula:

[0116] V f =k ln(t+m)+n

[0117] Among them, V f The cumulative volume of water separated from the emulsion after a set time; t is the set time; k, m, and n are the fitting parameters;

[0118] The emulsified water content of crude oil is calculated using the following formula:

[0119]

[0120] Among them, Vm V is the total volume of the emulsion; w V is the volume of the aqueous phase in the emulsion; f0 This represents the cumulative volume of water separated from the emulsion at t=0.

[0121] In summary, when implementing the low-temperature dynamic emulsification water content testing method for high water content crude oil provided by this invention:

[0122] This embodiment uses a certain oil sample as an example to test the emulsified water content of high water content crude oil under low temperature dynamic conditions. The physical property parameters of this oil are shown in Table 1:

[0123] Pour point / °C <![CDATA[Density at 50℃, kg / m 3 > Wax precipitation point / ℃ Wax content / m% Viscosity at 35℃ / mPa·s 28 844 50.3 16.6 237

[0124] Table 1 Physical properties of oil products

[0125] First, the oil-water mixture is stirred at different speeds to form an emulsion, and the torque value of the stirring mechanism is measured. Then, the effective viscosity of the oil-water mixture at the corresponding speed is calculated using the following formula:

[0126] In a stirred flow field, at a certain rotational speed, the viscosity of the emulsion and the stirring torque have the following relationship:

[0127] μ=aM b

[0128] Where μ is the viscosity of the emulsion; a and b are fitting parameters; and M is torque.

[0129] Based on actual oil data, parameters c, d, and e are fitted to obtain the formula for calculating the stirring speed corresponding to the shear rate in an actual unheated gathering and transportation pipeline:

[0130]

[0131] Where μ is the viscosity of the emulsion; a and b are fitting parameters; and M is torque.

[0132] Subsequently, based on the method derived from the relationship between energy dissipation rate and shear rate, the formula for calculating the average shear rate inside the preparation tank was derived:

[0133]

[0134] Where μ is the emulsion viscosity; N is the rotational speed of the stirring mechanism; and c, d, and e are the fitting parameters.

[0135] Based on actual oil data, parameters c, d, and e are fitted to obtain the formula for calculating the stirring speed corresponding to the shear rate in an actual unheated gathering and transportation pipeline:

[0136]

[0137] Formula for calculating the shear rate of unheated gathering and transportation pipelines:

[0138]

[0139] Where Q is the pipe flow rate; D is the pipe diameter;

[0140] The relationship between shear rate and rotation speed described above is shown in Table 2 below:

[0141] <![CDATA[Pipe flow rate / m 3 / s]]> <![CDATA[Pipe shear rate / s -1 > Rotational speed / r / min 10 11.6 100 15 17.5 200 20 23.3 300 30 30.7 400 40 46.6 500 50 58.2 600 60 69.9 700 70 81.5 800

[0142] Table 2. Relationship between shear rate and rotation speed

[0143] In this example, the rotation speed was 400 r / min, corresponding to a field shear rate of 30.7 s. -1 The values ​​of the fitting parameters a and b are obtained as 212.05 and 1.1289 respectively. Therefore, the viscosity of the emulsion can be expressed in the following form:

[0144] μ = 212.05M 1.1289

[0145] The viscosity of the emulsion can be calculated by measuring the torque of the stirring mechanism.

[0146] Then, the crude oil emulsified water content is calculated based on the oil-water separation interface data collected periodically by the metering acquisition component in the metering container.

[0147] By analyzing the change in the volume of water precipitated in the metering container over time, the cumulative volume of precipitated water V was obtained through fitting. f The correlation between V and the elapsed time t f =f(t), by extrapolating this relationship, the amount of free water in the oil-water emulsion when stirring has just stopped (t=0min) can be calculated. Taking this as the free water under dynamic conditions, and combining it with the total water content of the emulsion, the water content of the crude oil emulsion under dynamic conditions can be calculated. The specific formula is as follows:

[0148] V f =k ln(t+m)+n

[0149] Among them, V f The cumulative volume of water separated from the emulsion after a set time; t is the set time; k, m, and n are the fitting parameters;

[0150] After calculating the free water content in the oil-water emulsion at the moment when stirring just stopped (t = 0 min) using the above formula, the emulsion water content under low-temperature dynamic conditions of high water content crude oil can then be calculated using the following formula. The calculation formula is as follows:

[0151]

[0152] Among them, V m V is the total volume of the emulsion; w V is the volume of the aqueous phase in the emulsion; f0 This represents the cumulative volume of water separated from the emulsion at t=0.

[0153] In this embodiment, under high water content conditions of 70%-95%, emulsified water content experiments were conducted at temperatures 5°C above the pour point, 2°C above the pour point, at the pour point temperature, 3°C below the pour point, 5°C below the pour point, 8°C below the pour point, and 10°C below the pour point to test the crude oil emulsified water content under low-temperature dynamic conditions. The crude oil emulsified water content of the oil sample under different temperature conditions with a comprehensive water content of 70%-95% was measured by the control and data analysis system as follows: Figure 3 As shown.

[0154] This device and method for testing the low-temperature dynamic emulsified water content of high-water-content crude oil fully considers factors such as stirring speed, and strives to reproduce the actual situation of unheated gathering and transportation pipelines as much as possible. It provides a simple and convenient way to quantitatively test the low-temperature dynamic emulsified water content of crude oil in unheated gathering and transportation pipelines. This device is fully automatic and can determine the low-temperature dynamic water content of different types of high-water-content crude oil according to the set program, reducing human error. At the same time, this method can also explore the effects of different external transport temperatures, stirring speeds, and overall water content on the emulsified water content of crude oil, and calculate the viscosity of the oil-water mixture, providing a theoretical basis for determining the pressure drop boundary conditions of unheated gathering and transportation pipelines.

[0155] The various embodiments of the present invention have been described above. These descriptions are exemplary and not exhaustive, nor are they limited to the disclosed embodiments. Many modifications and variations will be apparent to those skilled in the art without departing from the scope and spirit of the described embodiments.

Claims

1. A method for testing the low-temperature dynamic emulsified water content of high-water-content crude oil, utilizing a device for testing the low-temperature dynamic emulsified water content of high-water-content crude oil, characterized in that... The device includes: A dynamic emulsion preparation structure includes a preparation tank and a stirring mechanism disposed inside the preparation tank. A temperature control component is disposed on the outside of the preparation tank. The stirring mechanism is connected to a stirring control unit, which is used to control the rotation speed of the stirring mechanism according to the properties of the crude oil. The measuring structure includes a metering container connected to the preparation tank, and a metering acquisition component is provided on one side of the metering container. The metering acquisition component is used to periodically collect oil-water separation interface data in the metering container. The processing unit is connected to the temperature control component and the metering and acquisition component. It is used to control the operation of the temperature control component and calculate the volume of water separated from the emulsion in the metering container after a set time based on the data collected by the metering and acquisition component. Then, the processing unit calculates the crude oil emulsion water content based on the volume of separated water. The method includes: Prepare an emulsion of crude oil and water at a set temperature; The prepared emulsion is injected into a metering container, and the oil-water separation interface data in the metering container is collected periodically by a metering acquisition component. The volume of water precipitated from the post-emulsion in the metering container after a set time is calculated based on the oil-water separation interface data collected periodically by the metering acquisition component. Then, the processing unit calculates the crude oil emulsion water content based on the volume of precipitated water. The calculation of crude oil emulsified water content based on the oil-water separation interface data collected periodically by the metering acquisition component in the metering container includes: The cumulative volume of water separated from the emulsion after a set time is calculated using the following formula: in, V f The cumulative volume of water separated from the emulsion after a set time; t Set the duration; k, m, n These are the fitting parameters; The emulsified water content of the crude oil is calculated using the following formula: in, V m This refers to the total volume of the emulsion; V w This represents the volume of the aqueous phase in the emulsion. V f0 for t The cumulative volume of water separated from the emulsion when =0.

2. The method for testing the low-temperature dynamic emulsified water content of high-water-content crude oil according to claim 1, characterized in that, The temperature control component includes: A temperature-controlled water jacket is wrapped around the outside of the preparation tank, and the temperature-controlled water jacket is provided with a water jacket inlet and a water jacket outlet; A temperature-controlled water bath is connected to the water jacket inlet and the water jacket outlet via a first pipeline and a second pipeline, respectively.

3. The method for testing the low-temperature dynamic emulsification water content of high-water-content crude oil according to claim 1, characterized in that, The bottom of the preparation tank is provided with a liquid outlet, and an electrically controlled valve is installed inside the liquid outlet.

4. The method for testing the low-temperature dynamic emulsified water content of high-water-content crude oil according to claim 1, characterized in that, The stirring mechanism includes a stirring motor, a stirring shaft, stirring blades, a speed monitoring sensor, and a stirring shaft torque monitoring sensor.

5. The method for testing the low-temperature dynamic emulsification water content of high-water-content crude oil according to claim 4, characterized in that, The processing unit includes a viscosity calculation module, which is used to calculate the viscosity of the emulsion based on the measurement results of the stirring shaft torque monitoring sensor and the rotation speed monitoring sensor.

6. The method for testing the low-temperature dynamic emulsified water content of high-water-content crude oil according to claim 1, characterized in that, The preparation of the crude oil and water emulsion at a set temperature includes injecting crude oil and water into a preparation tank in a set ratio, and stirring the crude oil and water with a stirring mechanism to form the emulsion.

7. The method for testing the low-temperature dynamic emulsification water content of high-water-content crude oil according to claim 1, characterized in that, After the emulsion is prepared, the rotational speed and torque of the stirring shaft of the stirring mechanism are measured, and the viscosity of the emulsion is calculated based on the rotational speed and the torque.

8. The method for testing the water content of high-water-content crude oil under low-temperature dynamic emulsification according to claim 7, characterized in that, The calculation of the viscosity of the emulsion based on the rotational speed and the torque includes calculating the viscosity of the emulsion using the following formula: Where μ is the viscosity of the emulsion; a、b These are the fitting parameters; M The torque is mentioned.

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