A moisture content monitoring device and method

Abstract

The present application belongs to the technical field of instrumentation, and in particular, relates to a water content monitoring device and method. Existing online methods for measuring the water content of crude oil generally measure the local water content, which cannot represent the overall water content inside the pipeline. The present application provides a water content monitoring device, including a pipe body, in which an electrical tomography sensor and a microwave sensor are arranged, the electrical tomography sensor is connected to a signal acquisition and processing unit, and the microwave sensor is connected to the signal acquisition and processing unit. The combination of the electrical tomography sensor and the microwave sensor realizes the identification of the gas-liquid flow shape and flow state inside the pipeline, and the transmission line measurement result is sufficient to represent the overall water content inside the pipeline.

Description

Technical Field

[0001] The present application belongs to the technical field of instruments and equipment, and in particular, relates to a moisture content monitoring device and method. Background Art

[0002] The water content of crude oil is an important parameter in the oil production and petrochemical industries. It is the key data in oil field production and oil product trading. It is of great significance to the production, dehydration, storage, transportation and sales of crude oil and crude oil refining and processing. If the water content of crude oil is not accurately monitored, it will directly affect the determination of the water and oil layers of the oil well, the estimation of crude oil production, and the prediction of the development life of the oil well.

[0003] In the early days, the measurement of water content in crude oil was mainly carried out by taking samples and sending them to the laboratory for distillation separation or centrifugal separation to analyze the water content of crude oil. However, due to the sampling and testing methods, complex operations, and delayed data information acquisition, it is impossible to reflect the changes in the water content of the oil wells in production in real time. Therefore, the demand for real-time online water content devices is becoming increasingly urgent. Many scientific research institutions and enterprises have made many explorations on the monitoring of water content in crude oil, using conductivity method, capacitance method, infrared method, ray method, radio frequency attenuation method, microwave resonance method, microwave transmission line method and other methods to achieve the measurement of water content in crude oil.

[0004] However, the existing online crude oil water content measurement methods generally measure local water content, which cannot represent the overall water content inside the pipeline. Summary of the invention

[0005] 1. Technical issues to be solved

[0006] Based on the problem that the existing online crude oil water content measurement methods generally measure local water content and cannot represent the overall water content situation inside the pipeline, the present application provides a water content monitoring device and method.

[0007] 2. Technical solution

[0008] In order to achieve the above-mentioned purpose, the present application provides a moisture content monitoring device, including a pipe body, in which an electrical tomography sensor and a microwave sensor are arranged, the electrical tomography sensor is connected to a signal acquisition and processing unit, and the microwave sensor is connected to the signal acquisition and processing unit.

[0009] Another implementation manner provided by the present application is: the electrical tomography sensor includes a plurality of joints, and the joints are evenly distributed along the cross section of the tube body.

[0010] Another embodiment provided by the present application is: the joint comprises a first transmission line, a first insulating medium and a first sealing ring, the first sealing ring is arranged on the first transmission line, the first insulating medium is arranged in the tube body, and the first sealing ring is arranged in the first insulating medium;

[0011] The first transmission line is provided with a signal input and output terminal, and the signal input and output terminal is connected to the signal acquisition and processing unit.

[0012] Another implementation manner provided by the present application is: the microwave sensor includes a plurality of second sealing rings, a plurality of second transmission lines and a plurality of second insulating media, the second sealing rings are arranged on the second transmission lines, the second sealing rings are arranged in the second insulating medium, the second insulating medium is arranged in the tube body, the second transmission line is connected to one end of the radio frequency connecting line, and the other end of the radio frequency connecting line is connected to the signal acquisition and processing unit.

[0013] Another implementation manner provided by the present application is: the signal acquisition and processing unit includes a first circuit, a second circuit, a third circuit, a control circuit, a human-computer interaction interface and a remote communication module, the first circuit is used for excitation generation and detection of the electrical tomography sensor, the second circuit is used for driving and detecting the microwave sensor, the third circuit is used for driving and detecting the temperature sensor, the control circuit is used to control the first circuit, the second circuit and the third circuit, the control circuit is used to implement a multi-sensor fusion algorithm, the human-computer interaction interface is used to display the water content results, and the remote communication module is used to remotely transmit the water content results.

[0014] Another implementation provided by the present application is: the electrical tomography sensor calculates the capacitance change caused by the disturbance and combines it with a deep learning algorithm to obtain the dielectric constant, and determines whether the liquid phase is in the oil continuous phase or the water continuous phase by judging the distribution of the dielectric constant.

[0015] Another implementation manner provided by the present application is: the tube body is a metal tube body, and the metal tube body is defined by a fluid flow path; the metal tube body is a hollow circular tube segment, and the metal tube body is connected to an external tube body through a flange or a clamp.

[0016] Another implementation manner provided by the present application is: it also includes a temperature sensor, wherein the temperature sensor, the electrical tomography sensor and the microwave sensor are arranged in sequence, and the temperature sensor is connected to the signal acquisition and processing unit.

[0017] Another embodiment provided by the present application is: the temperature sensor includes a temperature probe, the temperature probe extends into the interior of the tube body, and the temperature sensor is connected to the tube body by threading or welding; the temperature sensor is used to compensate for the dielectric constant of water at different liquid temperatures.

[0018] The present application also provides a water content monitoring method, and the water content monitoring device is applied to online water content monitoring of crude oil.

[0019] 3. Beneficial effects

[0020] Compared with the prior art, the moisture content monitoring device provided by the present application has the following beneficial effects:

[0021] The water content monitoring device provided in the present application relates to the field of monitoring and metering devices and instruments in the crude oil extraction and transportation links, adopts multi-sensor fusion technology, and is a high-precision crude oil water content online monitoring device.

[0022] The water content monitoring device provided in the present application is a multi-sensor fusion crude oil online water content monitoring device.

[0023] The water content monitoring device provided in this application is an online crude oil water content monitoring device that combines multiple sensor fusion solutions such as electrical tomography, microwave transmission line sensors, and temperature sensors. The electrical tomography sensor is used to monitor the rheological properties of the fluid inside the pipeline, especially the oil-water phase transition point characteristics, identify the flow shape and flow state inside the pipeline, and obtain the cross-sectional gas content.

[0024] In the moisture content monitoring device provided in the present application, the microwave sensor performs data compensation on the moisture content measured by the microwave sensor according to the monitoring results of the electrical tomography sensor and the results of the temperature sensor, thereby obtaining the final moisture content.

[0025] The moisture content monitoring device provided in the present application realizes full-range measurement of moisture content.

[0026] The moisture content monitoring device, low-power microwave sensor and electrical tomography sensor provided in this application have no radiation hazard, are harmless to the human body, and do not have any safety management issues.

[0027] The moisture content monitoring device provided in the present application, a combination of an electrical tomography sensor and a microwave sensor, combined with a mixer at the front end of the pipeline, ensures uniform mixing of oil and water, and realizes the identification of the gas-liquid flow pattern inside the pipeline. The transmission line measurement results are sufficient to represent the overall moisture content inside the pipeline.

[0028] The water content monitoring device provided in the present application introduces an electrical tomography sensor, which makes the rheological properties of the fluid inside the pipeline, mainly the oil-water phase transition properties, known. By judging the instantaneous liquid-filled moment in the pipeline, the microwave sensor only measures the oil-water two-phase flow, eliminating the influence of gas. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Figure 1 It is a schematic diagram of the structure of the moisture content monitoring device of the present application;

[0030] Figure 2 It is a schematic diagram of the structure of the microwave sensor of the present application;

[0031] Figure 3 This is a schematic diagram of the electrical tomography sensor structure of the present application;

[0032] Figure 4 This is a schematic diagram of the principle of the signal acquisition and processing unit of the present application;

[0033] Figure 5 This is a schematic diagram of the structure of the microwave drive detection circuit of the present application;

[0034] In the figure: 1-tube body; 2-electrical tomography sensor; 3-microwave sensor; 4-first transmission line; 5-first insulating medium; 6-first sealing ring; 7-signal input and output end; 8-second sealing ring; 9-second transmission line; 10-second insulating medium; 11-second signal input and output end. DETAILED DESCRIPTION

[0035] Hereinafter, the specific embodiments of the present application will be described in detail with reference to the accompanying drawings. According to these detailed descriptions, those skilled in the art can clearly understand the present application and can implement the present application. Without violating the principles of the present application, the features in the various embodiments can be combined to obtain new implementations, or certain features in certain embodiments can be replaced to obtain other preferred implementations.

[0036] The conductivity method mainly measures water content through impedance measurement. Therefore, for low water content measurements, due to the large impedance and severe signal attenuation, it is difficult to obtain accurate measurement signals, and it can only measure crude oil in the case of water continuous phase; the capacitance method monitors the water content by measuring the capacitance between the two electrodes of the sensor to monitor the dielectric constant. It is mainly used for low water content measurements. When the water content is high, the difference in the dielectric constants of oil and water is large, resulting in a significant reduction in sensitivity. It is often used in the case of oil continuous phase; infrared water content measurement is based on the difference in the absorption capacity of oil and water to the infrared spectrum to measure the water content. As long as the specific wavelength absorbed by water is extracted, the corresponding water content can be obtained by analyzing the change in the transmittance of the measured medium. Therefore, the accuracy is high and the full range of measurements can be achieved. However, if there is a mixture of water and oil in the measured fluid Uneven mixing will lead to large errors, and the effects of scaling and waxing will greatly affect the measurement accuracy. At the same time, the equipment price of the infrared method is relatively high, and the cost of installation and maintenance is also relatively large; the ray method uses a low-energy ray transmission scattering method to measure the water content of crude oil, using a γ radiation source as an excitation, and measures the water content by monitoring the attenuation of γ rays after passing through the crude oil. The measurement accuracy is high, and it can also achieve 0-100% full-scale measurement, but it brings problems with on-site radiation source management. At the same time, scaling, waxing and changes in salinity in water will also have a great impact on the measurement; the radio frequency attenuation method monitors the water content by monitoring the energy loss of the microwave signal after passing through the crude oil, but when the water content is high, the high-frequency microwave signal will be greatly attenuated, resulting in a large measurement error. It is generally used in the case of a water continuous phase. Microwave resonant cavity method and microwave transmission line method are water content measurement methods that have emerged in recent years. The resonant cavity method uses the principle that the change of the mixed dielectric constant of the fluid in the cavity causes the change of the resonant frequency to monitor the dielectric constant, thereby obtaining the water content of crude oil. However, its use is limited by the salinity of water and is usually only used in the case of oil continuous phase. The microwave transmission line method uses the fact that when microwaves are transmitted on the transmission line, the medium around the transmission line will affect the transmission speed and energy of the microwaves. The reduction in speed will cause the signal to shift in phase, and the reduction in energy will affect the attenuation of the microwaves. If there are free charge carriers or polar materials (such as water molecules) in the medium to be measured, this effect will increase proportionally. The effect of water on the signal is about 40 times that of other components (such as crude oil).

[0037] Therefore, it is clear how selectively sensitive the measurement is to water concentration. The correlation between moisture and dry matter allows very accurate measurements of water content at all stages of crude oil production. Compared with the capacitance method, the microwave transmission line method has higher sensitivity, but the sensing lines of the microwave transmission line method are mostly point-line type, with a small contact surface with the fluid. When there is mixed gas in the cavity fluid, the measurement accuracy will be greatly reduced. Therefore, it is generally necessary to arrange multiple sensors in the pipeline to improve the accuracy, but the average method is often used for the judgment of multi-sensor data, which cannot improve the measurement accuracy and stability.

[0038] In summary, the above-mentioned online crude oil water content measurement methods mainly have the following problems:

[0039] 1. There are situations where full-scale moisture content measurement cannot be achieved.

[0040] 2. There are security management issues.

[0041] 3. Seriously affected by factors such as temperature, water salinity, wax formation and scaling.

[0042] 4. It is generally a local moisture content measurement, which cannot represent the overall moisture content inside the pipeline.

[0043] 5. It is impossible to determine the rheological properties of the fluid inside the pipeline, mainly the oil-water phase transition characteristics.

[0044] 6. It is impossible to detect the flow pattern of the fluid inside the pipeline, and there is no accurate quantitative analysis of the impact on gas.

[0045] The name "microwave" is self-explanatory. It usually refers to electromagnetic waves with a wavelength between infrared and radio waves. The frequency range of microwaves is approximately between 300MHz and 300GHz. The corresponding wavelength is between 1 meter and 1mm. Microwave frequencies are higher than radio waves and are often also called "ultra-high frequency electromagnetic waves". In microwave measuring instruments, microwaves from the transmitter radiate products in the form of waves and are detected by the receiver. If the transmitter and receiver form a unit, these devices can be resonators, scattering sensors or reflection types. In the case where the transmitting and receiving units are separated, this is called transmission measurement. Microwave transmission measurement is widely used in the measurement of components of multiphase mixtures and water salinity.

[0046] Transmission lines are special cables or other structures in electronic engineering used to transmit alternating currents at radio frequencies, that is, currents whose frequencies are high enough that their wave properties must be considered, including but not limited to two-conductor transmission lines, including parallel lines, coaxial cables, strip lines, and microstrip lines.

[0047] See also Figures 1 to 5The present application provides a moisture content monitoring device, including a pipe body 1, in which an electrical tomography sensor 2 and a microwave sensor 3 are arranged, the electrical tomography sensor 2 is connected to a signal acquisition and processing unit, and the microwave sensor 3 is connected to the signal acquisition and processing unit.

[0048] A combination of flow pattern measurement methods based on other principles and water content measurement methods, such as a water content measurement scheme based on the electrical tomography principle combined with the gamma ray principle, is also acceptable.

[0049] Microwave transmission line crude oil online water content monitoring device and water content measurement method based on multi-sensor fusion.

[0050] The electrical tomography sensor 2 provides judgment of the flow shape and flow state inside the pipeline.

[0051] The electrical tomography sensor 2 provides phase transition point determination.

[0052] The front end of the tube body 1 is provided with a mixer to ensure uniform mixing of oil and water.

[0053] Furthermore, the electrical tomography sensor 2 includes a plurality of joints, and the joints are evenly distributed along the cross section of the tube.

[0054] Furthermore, the joint includes a first transmission line 4, a first insulating medium 5 and a first sealing ring 6, the first sealing ring 6 is arranged on the first transmission line 4, the first insulating medium 5 is arranged in the tube body 1, and the first sealing ring 6 is arranged in the first insulating medium 5; a signal input and output terminal 7 is arranged on the first transmission line 4, and the signal input and output terminal 7 is connected to the signal acquisition and processing unit.

[0055] The electrical tomography sensor 2 includes a metal tube body, an open-circuit metal transmission line, namely a first transmission line 4, a first insulating medium 5 and an O-ring, namely a first sealing ring 6, configured to provide constraints for low-frequency electromagnetic fields and allow electromagnetic fields to be transmitted therethrough at a certain frequency, including a signal input end and a signal output end, and connected to an external signal excitation and measurement system through a coaxial line; the first insulating medium 5 is an electrical connection that isolates the open-circuit metal transmission line from the tube wall, and constitutes a necessary structure for electromagnetic field signal transmission, and may include resin, hardened resin, polymer resin, epoxy resin or the like; due to the high internal pressure of the pipeline, in order to prevent the fluid from leaking through the contact portion between the first insulating medium 5 and the tube wall, a tapered thread structure is used between the first insulating medium 5 and the metal tube body to achieve effective sealing; in order to prevent the fluid from leaking through the open-circuit The gap between the metal transmission line and the first insulating medium 5 is penetrated, and an O-ring is used to seal the open-circuit metal transmission line and the first insulating medium 5. The above measures achieve the sealing reliability of the electrical tomography sensor 2; specifically, the electrical tomography sensor has a total of 8 joints, and the 8 joints are evenly distributed along the cross-section direction of the pipeline. Each joint includes an open-circuit metal transmission line, a first insulating medium 5 and an O-ring. First, the O-ring is put on the open-circuit metal transmission line, and then the first insulating medium 5 is screwed into the pipe body. Then, the metal transmission line with the O-ring is inserted into the pipe body from one end opening of the first insulating medium 5 to ensure that the end face of the metal transmission line is flush with the end face of the first insulating medium 5, and the signal input and output terminal 7 is connected to the signal acquisition and processing unit.

[0056] Furthermore, the microwave sensor 3 includes a plurality of second sealing rings 8, a plurality of second transmission lines 9 and a plurality of second insulating media 10, the second sealing rings 8 are arranged on the second transmission lines 9, the second sealing rings 8 are arranged in the second insulating medium 10, the second insulating medium 10 is arranged in the tube body 1, the second transmission line 9 is connected to one end of the radio frequency connecting line, and the other end of the radio frequency connecting line is connected to the signal acquisition and processing unit.

[0057] The microwave sensor 3 includes a metal transmission line, namely a second transmission line 9, a second insulating medium 10 and an O-ring, namely a second sealing ring 8, configured to provide constraints on the electromagnetic field and allow the electromagnetic field to be transmitted therethrough at a certain frequency; the metal transmission line is used for high-frequency electromagnetic field signal transmission, and includes a second signal input and output end 11, which is connected to an external signal excitation and measurement system through a coaxial line; the second insulating medium 10 is an electrical connection that isolates the metal transmission line from the pipe wall, and constitutes a necessary structure for electromagnetic field signal transmission, and may include resin, hardened resin, polymer resin, epoxy resin or the like; due to the high internal pressure of the pipeline, in order to prevent the fluid from leaking through the contact portion between the second insulating medium 10 and the pipe wall, the second insulating medium 10 and the metal pipe body A tapered thread structure is used to achieve effective sealing; in order to prevent the fluid from penetrating through the gap between the metal transmission line and the second insulating medium 10, an O-ring is used to seal the metal transmission line and the second insulating medium 10. The above measures are used to achieve the sealing reliability of the three parts of the microwave sensor; specifically, firstly, two O-rings are put on the metal transmission line, and then the two second insulating media 10 are screwed into the tube body, and then the metal transmission line with the O-ring is inserted into the tube body from the opening at one end of the insulating medium to ensure that the end face of the metal transmission line is flush with the end face of the insulating medium, one end of the two RF connecting wires are connected to the signal input end and the signal output end respectively, and the other ends of the two RF connecting wires are connected to the signal acquisition and processing system.

[0058] Figure 5 The basic structure diagram of the microwave sensor 3 driving and detection circuit is given. In order to reduce and avoid the loss of microwave signals in the transmission process, the microwave sensor 3 driving and detection circuit needs to perform characteristic impedance matching. The characteristic impedance is 50 ohms, which is an important means to improve the consistency and stability of microwave circuits. The directional coupler can distribute the microwave signal into two signals with consistent frequency phases at different powers. If the signal power used as the reference path is close to the signal power of the driving sensor, when the attenuation of the microwave signal after passing through the sensor is too large or too small, it will cause the detector to be insensitive, thereby losing the detection accuracy. The addition of coupling can reduce the microwave signal power of the detector reference path in proportion to the microwave signal driving the sensor, thereby improving the sensitivity of the detector amplitude measurement and realizing the detection of mineralization.

[0059] The microwave sensor 3 monitors the moisture content based on the principle that the dielectric constant around the transmission line determines the transmission speed of the microwave when the microwave is transmitted on the transmission line. The microwave signal is divided into a reference signal and a drive signal. When the amplitude and phase of the drive signal flowing through the microwave sensor 3 change relative to the reference signal, it means that the dielectric constant of the medium around the sensor has changed. Since the dielectric constants of oil and water are known, the dielectric constant of the mixed liquid can be obtained by calculation, thereby obtaining the moisture content. Specifically, the dielectric constant of the medium to be measured can be determined by measuring the phase shift and attenuation of the electromagnetic wave passing through the medium. The basic principle of electromagnetic wave propagation in lossy media has been well described in many literatures. Specifically, the general equation for the propagation of the electric field in the z direction of a forward propagating electromagnetic wave with an x-component and a y-component of the electric field is described by the following equation 1:

[0060]

[0061] in

[0062] E: electric field vector, E1: electric field in the x direction, E2: electric field in the y direction, ψ: phase angle between the x component and the y component, k: phase constant or wave number.

[0063] For electromagnetic waves propagating in a lossy medium, such as an oil-water mixture, the wave number k is a complex number, as shown in Equation 2 below:

[0064] k=α+jβ Equation 2

[0065] Among them, α: electromagnetic wave power attenuation coefficient, β: electromagnetic wave phase constant.

[0066] e -jkz =e -αz e -jβz Equation 3

[0067] The power attenuation coefficient and phase constant can be expressed by Equation 4 and Equation 5:

[0068]

[0069]

[0070] Where: ε′: real part of the complex dielectric constant of the medium, ε″: real part of the complex dielectric constant of the medium, ω: operating angular frequency, μ: magnetic permeability of the medium.

[0071] The complex dielectric constant ε of the medium can be described according to Equation 6:

[0072] ε=ε′-jε″ Equation 6

[0073] For air and crude oil, the imaginary part of the dielectric constant is equal to 0. For water, the complex dielectric constant of water can be described by the single Debye relaxation law, as shown in Equation 7:

[0074]

[0075] Among them, ε 水 : Complex dielectric constant of water, ε ∞ : Dielectric constant at infinite frequency, ε s : static dielectric constant, ω: operating angular frequency, σ 水 : Electrical conductivity of water, ε0: Boltzmann constant.

[0076] The real part of the dielectric constant of water can be derived as Equation 8:

[0077]

[0078] Among them, ε s : Static dielectric constant, ε ∞ : dielectric constant at infinite frequency, τ: dipole relaxation time.

[0079] According to plane wave theory, the attenuation constant and phase shift constant can be obtained from the attenuation and phase shift, as shown in Equation 9 and Equation 10:

[0080]

[0081]

[0082] M0 and θ0 are the initial amplitude and phase, M m and θ m is the measured amplitude and phase, and L is the length of the transmission line. The attenuation constant and phase shift coefficient of the electromagnetic wave passing through the medium to be measured are calculated by equations 9 and 10. Combined with equations 4 and 5, the mixed dielectric constant of the medium to be measured is calculated. Combined with the corrected water dielectric constant, the water content is obtained according to the relationship between the dielectric constant and the water content. Since the crude oil and water mixture mainly exists in a mixed state, namely, oil continuous phase (oil as the external phase, water as the internal phase) and water continuous phase (water as the external phase, oil as the internal phase), the water content corresponding to the same dielectric constant in the two cases is different, and needs to be calculated separately.

[0083] Furthermore, the signal acquisition and processing unit includes a first circuit, a second circuit, a third circuit, a control circuit, a human-computer interaction interface and a remote communication module, the first circuit is used for excitation generation and detection of the electrical tomography sensor, the second circuit is used for driving and detecting the microwave sensor, the third circuit is used for driving and detecting the temperature sensor 80, the control circuit is used to control the first circuit, the second circuit and the third circuit, the control circuit is used to implement a multi-sensor fusion algorithm, the human-computer interaction interface is used to display the water content results, and the remote communication module is used to remotely transmit the water content results.

[0084] The signal acquisition processing unit includes the excitation generation and detection circuit of the electrical tomography sensor 2, the driving and detection circuit of the microwave sensor 3, the driving and detection circuit of the temperature sensor 80, the control circuit for controlling the above circuits and realizing the multi-sensor fusion algorithm, the button and display circuit for providing the local human-computer interaction interface, and the bus interface and RJ45 interface and driving circuit for providing remote communication, etc.;

[0085] The overall structure of the signal acquisition and processing unit is as follows: Figure 4 As shown, the driving and detection circuits of the electrical tomography sensor 2, the microwave sensor 3, and the temperature sensor 80 are controlled by the control circuit to perform data analysis and calculation of the control and detection results. The water content results obtained after conversion and processing are directly displayed on the human-computer interaction interface locally, and can be transmitted remotely via TCP / IP or RS485 bus.

[0086] Furthermore, the electrical tomography sensor 2 calculates the capacitance change caused by the disturbance and obtains the dielectric constant by combining the deep learning algorithm, and determines whether the liquid phase is in the oil continuous phase or the water continuous phase by judging the distribution of the dielectric constant.

[0087] The excitation of the electrical tomography sensor 2 uses DDS technology to generate a sinusoidal excitation signal with a frequency between 100KHz-3000MHz. The excitation signal is converted into a corresponding current signal through a voltage-controlled constant current source, and the sensor is driven by the current signal. The electrical tomography sensor 2 is a multi-electrode sensor. Different channels are switched by the analog switch chip on the driving circuit, so that the excitation source is applied to different electrodes, and the signals received by other electrode pairs outside the excitation electrode are measured at the same time, so as to monitor the electromagnetic information of different directions and different flow layers, so as to judge the flow type flowing through the sensor.

[0088] The microwave transmission line sensor structure based on the reliable sealing method proposed in this application ensures the safety of application in industrial production environment

[0089] The invention provides an electrical tomography sensor structure with a reliable sealing method.

[0090] Furthermore, the tube body 1 is a metal tube body, and the metal tube body is defined by a fluid flow path. The metal tube body is a hollow circular tube section, and the metal tube body is connected to an external tube body through a flange or a clamp.

[0091] Furthermore, it also includes a temperature sensor 80. The temperature sensor 80, the electrical tomography sensor and the microwave sensor are arranged in sequence, and the temperature sensor 80 is connected to the signal acquisition processing unit.

[0092] Furthermore, the temperature sensor 80 includes a temperature probe, which extends into the interior of the tube body. The temperature sensor 80 is connected to the tube body by threading or welding; the temperature sensor 80 is used to compensate for the dielectric constant of water at different liquid temperatures.

[0093] The temperature sensor 80 is located at the front of the tube body, the electrical tomography sensor 2 is located in the middle of the tube body, and the microwave sensor 3 is located at the rear of the tube body. The signal acquisition and processing system is electrically connected to the temperature sensor 80, the microwave sensor 3, and the electrical tomography sensor 2 for acquiring and processing the signals of each sensor.

[0094] The temperature sensor 80 is used to measure the medium temperature, provide early warning, and provide compensation.

[0095] The temperature probe of the temperature sensor 80 extends into the metal tube body to compensate for the dielectric constant of water at different liquid temperatures. The temperature sensor 80 is fixed to the tube body by threading or welding to achieve effective sealing to ensure that the fluid does not leak.

[0096] The present application also provides a water content monitoring method, and the water content monitoring device is applied to online water content monitoring of crude oil.

[0097] Example

[0098] See also Figure 1 , Figure 1 It is a structural schematic diagram of an online crude oil water content monitoring device integrating multiple sensing technologies proposed in the present invention, including a metal pipe body that limits the fluid flow path, a microwave sensor 2, an electrical tomography sensor 3, a temperature sensor 80 and a signal acquisition and processing system.

[0099] The metal pipe body is usually made of a hollow circular pipe section made of metal. Both ends of the pipe body 1 are connected to the external pipe body by flanges, clamps or other process connection methods; the temperature sensor 80 is located at the front of the pipe body, the electrical tomography sensor 2 is located in the middle of the pipe body, and the microwave sensor 3 is located at the rear of the pipe body. The signal acquisition and processing system is electrically connected to the temperature sensor 80, the microwave sensor 3, and the electrical tomography sensor 2 for collecting and processing the signals of each sensor.

[0100] When the oil-gas-water multiphase flow passes through the metal pipe, the microwave generation and detection circuit will detect the attenuation and phase shift through equations 9 and 10 to obtain the attenuation constant α m and the phase shift constant β m ,

[0101]

[0102]

[0103] M0 and θ0 are the initial amplitude and phase, M m and θ m are the measured amplitude and phase, and L is the length of the transmission line.

[0104] Combining equation 4 and equation 5, the mixed dielectric constant of the medium to be tested is calculated. Combined with the corrected water dielectric constant, it is determined whether the medium to be tested belongs to the oil continuous phase or the water continuous phase. Then, the water content is obtained according to the relationship equation between the dielectric constant and the water content.

[0105] Since oil, gas and water are three media in the three-phase flow, gas will have a certain influence on the water content measurement. In order to eliminate the influence of gas, the electrical tomography module introduced in the present invention can obtain real-time gas-liquid distribution. By judging the instantaneous full liquid moment in the pipeline, the microwave sensor 3 only measures the oil-water two-phase flow, eliminating the influence of gas.

[0106] The crude oil online water content monitoring device with a multi-sensor fusion solution proposed in this application solves the following problems:

[0107] 1. Full range measurement of moisture content.

[0108] 2. The low-power microwave sensor 3 and the electrical tomography sensor 2 have no radiation hazard, are harmless to the human body, and do not pose any safety management issues.

[0109] 3. The moisture content measurement algorithm adopted realizes automatic compensation of temperature and water salinity, and the special coating treatment of the transmission line avoids the influence of factors such as waxing and scaling.

[0110] 4. The combination of the electrical tomography sensor 2 and the microwave sensor 3, combined with the mixer at the front end of the pipeline, ensures that the oil and water are mixed evenly, and realizes the identification of the gas-liquid flow pattern inside the pipeline. The transmission line measurement results are sufficient to represent the overall water content inside the pipeline.

[0111] 5. The introduction of the electrical tomography sensor 2 makes the rheological properties of the fluid inside the pipeline, mainly the oil-water phase transition properties, known, and enables accurate quantitative analysis of the gas impact.

[0112] Although the present application is described above with reference to specific embodiments, it should be understood by those skilled in the art that many modifications may be made to the configurations and details disclosed in the present application within the principles and scope disclosed in the present application. The scope of protection of the present application is determined by the appended claims, and the claims are intended to cover all modifications included in the equivalent literal meaning or scope of the technical features in the claims.

Claims

1. A moisture content monitoring device, characterized in that: It comprises a tube body, a mixer is arranged at the front end of the tube body, an electrical tomography sensor and a microwave sensor are arranged in the tube body, the electrical tomography sensor is connected to a signal acquisition processing unit, the microwave sensor is connected to the signal acquisition processing unit, the electrical tomography sensor comprises a plurality of joints, the joints are evenly distributed along the cross section of the tube body, the joints comprise a first transmission line, a first insulating medium and a first sealing ring, the first sealing ring is arranged on the first transmission line, the first insulating medium is arranged in the tube body, and the first sealing ring is arranged in the first insulating medium; a signal input and output terminal is arranged on the first transmission line, and the signal input and output terminal is connected to the signal acquisition processing unit.

2. The moisture content monitoring device according to claim 1, characterized in that: The microwave sensor includes a plurality of second sealing rings, a plurality of second transmission lines and a plurality of second insulating media. The second sealing rings are arranged on the second transmission lines, the second sealing rings are arranged in the second insulating medium, the second insulating medium is arranged in the tube body, the second transmission lines are connected to one end of the radio frequency connecting line, and the other end of the radio frequency connecting line is connected to the signal acquisition and processing unit.

3. The moisture content monitoring device according to claim 1, characterized in that: The signal acquisition and processing unit includes a first circuit, a second circuit, a third circuit, a control circuit, a human-computer interaction interface and a remote communication module. The first circuit is used for excitation generation and detection of an electrical tomography sensor, the second circuit is used for driving and detecting a microwave sensor, and the third circuit is used for driving and detecting a temperature sensor. The control circuit is used to control the first circuit, the second circuit and the third circuit. The control circuit is used to implement a multi-sensor fusion algorithm. The human-computer interaction interface is used to display water content results. The remote communication module is used to remotely transmit the water content results.

4. The moisture content monitoring device according to claim 1, characterized in that: The electrical tomography sensor calculates the capacitance change caused by the disturbance and obtains the dielectric constant by combining the deep learning algorithm. It determines whether the liquid phase is in the oil continuous phase or the water continuous phase by judging the distribution of the dielectric constant.

5. The moisture content monitoring device according to any one of claims 1 to 4, characterized in that: The pipe body is a metal pipe body, a fluid flow path is defined in the metal pipe body, and the metal pipe body is connected to an external pipe body through a flange or a clamp.

6. The moisture content monitoring device according to claim 5, characterized in that: It also includes a temperature sensor. The temperature sensor, the electrical tomography sensor and the microwave sensor are arranged in sequence, and the temperature sensor is connected to the signal acquisition and processing unit.

7. The moisture content monitoring device according to claim 6, characterized in that: The temperature sensor comprises a temperature probe, the temperature probe extends into the interior of the tube body, and the temperature sensor is connected to the tube body by means of threads or welding; the temperature sensor is used to achieve compensation of the dielectric constant of water at different liquid temperatures.

8. A method for monitoring moisture content, characterized in that: The water content monitoring device according to any one of claims 1 to 7 is applied to online water content monitoring of crude oil.

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