Adaptive variable current source ultrasonic flow measurement method based on CTMU

Abstract

The application provides a CTMU-based adaptive variable current source ultrasonic flow measurement method, and belongs to the technical field of downhole pipeline flow measurement. The method comprises the following steps: adopting a least square method to establish a flow rate influencing factor matrix, a measured flow rate matrix, a residual variable matrix and an unmeasured flow rate matrix; based on the flow rate influencing factor matrix, the measured flow rate matrix, the residual variable matrix and the unmeasured flow rate matrix, a multiple regression equation is established; based on the multiple regression equation, the unmeasured flow rate of fluid in a downhole pipeline is predicted; or, according to the measured flow rate and the flow rate influencing factor, a sum of squared deviations of the measured flow rate is calculated; and based on the sum of squared deviations of the measured flow rate, the unmeasured flow rate is predicted. The application can improve the accuracy of ultrasonic flow measurement and has strong ease of use and practicality.

Description

Technical Field

[0001] This application relates to the field of downhole pipeline flow measurement technology, and specifically to an adaptive variable current source ultrasonic flow measurement method based on CTMU. Background Technology

[0002] The accuracy of flow measurement in downhole pipelines is closely related to the operating time. Oil wells are usually in continuous operation unless there are special circumstances, which makes the accuracy of flow measurement particularly important.

[0003] Currently, commonly used flow measurement methods include orifice plate flow measurement, eddy current flow measurement, and electromagnetic flow measurement. However, these methods have drawbacks. Based on these drawbacks, ultrasonic flowmeters are highly suitable for measuring downhole oil flow in terms of accuracy, range, pipe diameter, and pressure loss.

[0004] In existing technologies, for split-type ultrasonic flow meters, signal propagation delay and temperature changes in the measurement circuit both affect the ultrasonic propagation time measurement, resulting in low accuracy. Therefore, improving the accuracy of ultrasonic flow measurement remains an unsolved problem. Summary of the Invention

[0005] The purpose of this application is to provide an adaptive variable current source ultrasonic flow measurement method based on CTMU, which can solve the problem of low accuracy in existing ultrasonic flow measurement technologies.

[0006] In a first aspect, embodiments of this application provide an adaptive variable current source ultrasonic flow measurement method based on a CTMU, implemented using an ultrasonic excitation circuit, the method comprising: The least squares method was used to establish the matrix of factors affecting flow velocity, the matrix of measured flow velocity, the matrix of residual variables, and the matrix of unmeasured flow rate. A multiple regression equation is established based on the flow velocity influencing factor matrix, the measured flow velocity matrix, the residual variable matrix, and the unmeasured flow rate matrix. Based on the multiple regression equation, the unmeasured flow rate of fluid in downhole pipelines is predicted; Alternatively, the sum of squares of deviations of the measured flow rate can be calculated based on the measured flow velocity and the factors affecting the flow velocity. Predict unmeasured flow rates based on the sum of squared deviations of measured flow rates.

[0007] In one possible implementation of the first aspect, the expression for the velocity influencing factor matrix is: Its transpose is , where n represents the number of factors affecting flow velocity; The expression for the measured velocity matrix is: , where n represents the number of flow velocities measured; The expression for the residual variable matrix is: Its transpose is , where k represents the number of residual variables; The expression for the unmeasured flow matrix is: Its transpose is , where m represents the number of unmeasured flow rates.

[0008] In one possible implementation of the first aspect, the expression for the multiple regression equation is as follows:

[0009] .

[0010] In one possible implementation of the first aspect, the residual variable is calculated according to the following formula:

[0011] Among them, e k σ represents the residual variable. k Indicates factors affecting flow velocity. This represents the average of the measured flow velocities. This represents the mean of the factors affecting flow velocity. and Indicates an intermediate variable.

[0012] In one possible implementation of the first aspect, the expression for the sum of squared deviations of the measured flow rate is as follows: ;

[0013] Among them, g 2 SSE represents the sum of squared deviations of the measured flow rates, and e represents the difference in the measured flow rates. and l 2 Indicates an intermediate variable.

[0014] In one possible implementation of the first aspect, the method further includes: The total propagation time of the ultrasound is calculated based on the propagation time of the ultrasound in both downstream and upstream directions. The total flow rate of the fluid in the downhole pipeline is calculated based on the total propagation time.

[0015] In one possible implementation of the first aspect, prior to calculating the total propagation time of the ultrasound based on its propagation time in the downstream and upstream currents, the method further includes: The propagation time of ultrasound in downstream and upstream currents can be calculated using the following formulas:

[0016]

[0017] Where t1 represents the propagation time of the ultrasonic wave in the downstream direction, t2 represents the propagation time of the ultrasonic wave in the upstream direction, L represents the distance between the two ultrasonic transducers, c represents the propagation speed of the ultrasonic wave entering the ultrasonic transducer, v represents the flow velocity of the fluid in the wellbore, and θ represents the refraction angle of the ultrasonic wave when it enters the wellbore wall from the ultrasonic transducer.

[0018] In one possible implementation of the first aspect, the total propagation time of the ultrasonic wave is calculated based on its propagation time in the downstream and upstream directions, including: The difference between the propagation time of ultrasound waves in the countercurrent and in the downstream is taken as the total propagation time. The specific calculation formula is as follows:

[0019]

[0020] Where Λt represents the total propagation time.

[0021] In one possible implementation of the first aspect, the total flow rate of the fluid in the downhole pipeline is calculated based on the total propagation time, including: The total flow rate of the fluid in the downhole pipeline can be calculated using the following formula: ,

[0022] Where Q represents the total flow rate of fluid in the downhole pipeline, and D represents an intermediate variable.

[0023] In one possible implementation of the first aspect, the ultrasonic excitation circuit includes: The first CTMU module, connected to the pulse transmission module, is used to output transmission signals and receive differential analog signals output by the first ultrasonic transducer. A pulse transmission module, connected to the first comparator, is used to transmit pulse waveforms; The first operational amplifier module is connected to the first ultrasonic transducer and is used to amplify the differential analog signal output by the first ultrasonic transducer. The first comparator, connected to the first operational amplifier module, is used to convert the amplified differential analog signal into a digital signal. The second operational amplifier module is connected to the second ultrasonic transducer and is used to amplify the differential analog signal output by the second ultrasonic transducer. The second comparator, connected to the second operational amplifier module, is used to convert the amplified differential analog signal into a digital signal. The second CTMU module, connected to the second comparator, is used to measure the propagation time of ultrasonic waves in both downstream and upstream directions.

[0024] In one possible implementation of the first aspect, the pulse emission module includes a TTL or CMOS transistor.

[0025] In one possible implementation of the first aspect, the first operational amplifier module or the second operational amplifier module includes: a first-stage operational amplifier and a second-stage operational amplifier.

[0026] In one possible implementation of the first aspect, the circuit further includes: a first analog switch and a second analog switch; The first terminal of the first analog switch is connected to the output terminal of the first ultrasonic transducer, and the second terminal of the first analog switch is connected to the non-inverting input terminal of the first operational amplifier module. The first terminal of the second analog switch is connected to the output terminal of the second ultrasonic transducer, and the second terminal of the second analog switch is connected to the non-inverting input terminal of the second operational amplifier module.

[0027] Secondly, embodiments of this application provide an adaptive variable current source ultrasonic flow measurement device based on a CTMU, the device comprising: The first establishment unit is used to establish the velocity influencing factor matrix, the measured velocity matrix, the residual variable matrix, and the unmeasured flow matrix using the least squares method. The second establishment unit is used to establish a multiple regression equation based on the velocity influencing factor matrix, the measured velocity matrix, the residual variable matrix, and the unmeasured flow rate matrix. The first prediction unit is used to predict the unmeasured flow rate of fluid in downhole pipelines based on multiple regression equations. Alternatively, the calculation unit is used to calculate the sum of squares of deviations of the measured flow rate based on the measured flow velocity and the factors affecting the flow velocity; The second prediction unit is used to predict the unmeasured flow rate based on the sum of squared deviations of the measured flow rate.

[0028] Thirdly, embodiments of this application provide an electronic device, including a memory, a processor, and a computer program stored in the memory and executable on the processor. When the processor executes the computer program, it implements the adaptive variable current source ultrasonic flow measurement method based on CTMU as described in any of the first aspects above.

[0029] Fourthly, embodiments of this application provide a computer-readable storage medium storing a computer program that, when executed by a processor, implements the adaptive variable current source ultrasonic flow measurement method based on CTMU as described in any of the first aspects above.

[0030] Fifthly, embodiments of this application provide a computer program product that, when run on an electronic device, causes the electronic device to execute the adaptive variable current source ultrasonic flow measurement method based on CTMU as described in any of the first aspects above.

[0031] This application employs the least squares method to establish a velocity influencing factor matrix, a measured velocity matrix, a residual variable matrix, and an unmeasured flow rate matrix. Based on these matrices, a multiple regression equation is established. The unmeasured flow rate of fluid in downhole pipelines is then predicted based on the multiple regression equation. Alternatively, the sum of squared deviations of the measured flow rate is calculated based on the measured velocity and velocity influencing factors. The unmeasured flow rate is then predicted based on the sum of squared deviations of the measured flow rate.

[0032] The proposed solution can improve the accuracy of ultrasonic flow measurement and has strong ease of use and practicality.

[0033] Other features and advantages of this application will be described in detail in the following detailed description section. Attached Figure Description

[0034] To more clearly illustrate the technical solutions in the embodiments of this application, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0035] Figure 1 This is a schematic diagram of the steps of the adaptive variable current source ultrasonic flow measurement method based on CTMU provided in the embodiments of this application; Figure 2 This is a schematic diagram of the ultrasonic excitation circuit provided in the embodiments of this application; Figure 3 This is a schematic diagram illustrating the working principle of the CTMU provided in the embodiments of this application; Figure 4 This is a schematic diagram of the CTMU charge-discharge curve provided in the embodiments of this application; Figure 5 This is a schematic diagram of dual-wedge forward and reverse flow detection and quad-wedge forward and reverse flow detection provided in the embodiments of this application; Figure 6This is a schematic diagram of the traffic flow time relationship provided in the embodiments of this application; Figure 7 This is a schematic diagram of the fluid injection experimental pipeline provided in an embodiment of this application; Figure 8 This is a schematic diagram of the structure of the adaptive variable current source ultrasonic flow measurement device based on CTMU provided in the embodiments of this application; Figure 9 This is a schematic diagram of the electronic device provided in the embodiments of this application. Detailed Implementation

[0036] In the following description, specific details such as particular system architectures and techniques are set forth for illustrative purposes and not for limitation, in order to provide a thorough understanding of the embodiments of this application. However, those skilled in the art will understand that this application can also be implemented in other embodiments without these specific details. In other instances, detailed descriptions of well-known systems, apparatuses, circuits, and methods have been omitted so as not to obscure the description of this application with unnecessary detail.

[0037] It should be understood that, when used in this specification and the appended claims, the term "comprising" indicates the presence of the described features, integrals, steps, operations, elements and / or photovoltaic modules, but does not exclude the presence or addition of one or more other features, integrals, steps, operations, elements, photovoltaic modules and / or combinations thereof.

[0038] It should also be understood that the terminology used in this specification is for the purpose of describing particular embodiments only and is not intended to limit the scope of the application. As used in this specification and the appended claims, the singular forms “a,” “an,” and “the” are intended to include the plural forms unless the context clearly indicates otherwise.

[0039] It should also be further understood that the term “and / or” as used in this application specification and the appended claims means any combination of one or more of the associated listed items and all possible combinations, and includes such combinations.

[0040] As used in this specification and the appended claims, the term "if" may be interpreted, depending on the context, as "when," "once," "in response to determination," or "in response to detection." Similarly, the phrase "if determined" or "if [the described condition or event] is detected" may be interpreted, depending on the context, as "once determined," "in response to determination," "once [the described condition or event] is detected," or "in response to detection of [the described condition or event]."

[0041] Furthermore, in the description of this application, the terms "first," "second," "third," etc., are used only to distinguish descriptions and should not be construed as indicating or implying relative importance.

[0042] References to "one embodiment" or "some embodiments" as described in this specification mean that one or more embodiments of this application include a specific feature, structure, or characteristic described in connection with that embodiment. Therefore, the phrases "in one embodiment," "in some embodiments," "in some other embodiments," "in other embodiments," etc., appearing in different parts of this specification do not necessarily refer to the same embodiment, but rather mean "one or more, but not all, embodiments," unless otherwise specifically emphasized. The terms "comprising," "including," "having," and variations thereof mean "including but not limited to," unless otherwise specifically emphasized.

[0043] The efficiency of downhole pipeline flow monitoring directly affects the stability and efficiency of oil well production. As a key task in daily oil well management, accurate flow information is essential for making reasonable production plans and operational arrangements. However, the accuracy of downhole flow measurement is closely related to the operating time. Oil wells typically operate continuously unless there are special circumstances, making the accuracy of flow measurement particularly important.

[0044] Currently, commonly used flow measurement methods mainly include orifice plate flow measurement, eddy current flow measurement, and electromagnetic flow measurement. Orifice plate flow measurement is a differential pressure measurement method, primarily composed of a standard orifice plate and a multi-parameter differential pressure transmitter. However, due to its complex and fixed structure, it suffers from significant pressure loss. Eddy current flow measurement utilizes the principle that fluid velocity and eddy current frequency are proportional, using piezoelectric elements to sense eddy current vibrations. Its application is limited to a small pipe diameter range and narrows its application scenarios. Electromagnetic flow measurement uses a transmitter to measure the voltage of the sensor, converting the voltage into flow rate. However, it cannot measure liquids with low conductivity and is not resistant to high temperatures.

[0045] Based on the shortcomings of the aforementioned technologies, ultrasonic flowmeter measurement methods are well-suited for measuring downhole oil flow in terms of accuracy, range, pipe diameter, and pressure loss. The patent "A Method for Improving the Measurement Accuracy of Time-of-Flight Ultrasonic Flowmeters" proposes a method for measuring downhole flow using a time-of-flight ultrasonic flowmeter. This method designs a measurement sequence and incorporates fluid flow rate, temperature, and other information into the flow measurement model, thereby enhancing the adaptability of the time-of-flight method in downhole flow measurement.

[0046] This method can measure fluid velocity by utilizing the time difference between the forward and reverse propagation of pulsed ultrasound in a fluid. However, for split-type ultrasonic flow meters, the signal propagation delay in the measurement circuit and changes in circuit temperature will affect the measurement of ultrasonic propagation time.

[0047] In the existing technology, there are many types of flow meters used in the field of fluid measurement. Based on the different measurement principles, they can be divided into: rotor flow meters, electromagnetic flow meters, turbine flow meters, differential pressure flow meters, mass flow meters, vortex flow meters, ultrasonic flow meters, etc. Among them, electromagnetic flow meters, orifice plate flow meters, turbine flow meters, vortex flow meters, and ultrasonic flow meters account for the main market share.

[0048] Orifice plate flow meters belong to the small-range differential pressure flow meter category and can be used for measuring the flow rate of gas and liquid fluids. They are widely used in water conservancy, liquefaction, petroleum, chemical, natural gas, heating, water supply, and other production and daily life fields. They have advantages such as low price, simple structure, and wide application range. When a fluid flows, the change in flow velocity is overall and continuous.

[0049] Based on the known properties of the fluid being measured, the relationship between fluid velocity and pressure difference can be derived, and the flow rate can then be calculated. However, orifice plate flow meters are somewhat complex to implement and contain certain mechanical structures. They suffer from drawbacks such as generally poor test repeatability, low adaptability, and small measuring range, making them unable to meet the measurement accuracy requirements of practical applications.

[0050] When a fluid flows over objects with different surface features, it generates vortex flows with specific frequencies. These vortex frequencies correspond to the fluid velocity. Based on this phenomenon, by fixing a non-streamlined vortex generator within the fluid and then calculating the relationship between the measured vortex generation frequency and the fluid velocity, the flow rate of the fluid can be deduced. This is the measurement principle of a vortex flow meter.

[0051] Vortex flow meters have advantages such as good repeatability, wide measurement range, low pressure loss, and simple product structure. However, to ensure the stability of the measured vortex frequency, sufficiently long straight pipe sections are required upstream and downstream of the flow measurement point, which places relatively high demands on installation conditions.

[0052] A turbine flow meter is essentially a magnetoelectric device. To measure flow rate, the turbine is placed in the fluid being measured. Under the impact of the fluid, the turbine rotates, cutting magnetic field lines and generating a considerable amount of electricity. Since the generated electricity is proportional to the turbine's rotational speed, the fluid velocity can be calculated using relevant formulas and converted into a flow rate measurement.

[0053] Turbine flow meters have advantages such as high measurement accuracy, good result repeatability, and simple structure. However, they require pipe damage control during on-site installation, are difficult to maintain, require a stable fluid flow rate, and are susceptible to damage from impurities in the fluid, resulting in low environmental adaptability.

[0054] Electromagnetic flowmeters operate on Faraday's law of electromagnetic induction, indirectly measuring the flow rate of a conductive fluid by measuring changes in its electromotive force. Installation requires no pipe-damping operations, produces no pressure loss, is less affected by impurities, has a wide measurement range, and is easy to maintain in real-time. They can be used to measure the flow rate of contaminated fluids containing particulate matter, such as pulp produced during papermaking.

[0055] Because the electromagnetic effect requires the measured fluid to have high conductivity, this type of flow meter cannot be used to measure the flow rate of gaseous fluids or liquid fluids with low conductivity. Moreover, the fluid temperature will also affect the measurement results.

[0056] The theoretical basis of ultrasonic flow measurement technology is that when an ultrasonic pulse signal propagates in a fluid, the different speeds and states of the fluid will modulate the ultrasonic pulse signal in different ways. By comparing the differences between the original and modulated ultrasonic pulse signals, and then calculating the fluid velocity data according to the corresponding relationship, the flow information can be obtained.

[0057] Ultrasonic flow measurement operates on various principles, such as the Doppler method and the time-of-flight method. Therefore, fluid properties do not limit the field application of ultrasonic flow meters. They can be used to measure the flow rate of fluids in various pipe diameters, as well as highly corrosive, high-viscosity, volatile, flammable, and explosive hazardous fluids. They are unaffected by electrical conductivity, are easy to maintain, and can be used for non-contact fluid measurement.

[0058] Comparative analysis shows that ultrasonic flow meters outperform other flow meters in all performance parameters, possessing excellent applicability and applicable to various fields such as oil transportation, liquefaction production, and hydrological measurement. Based on the needs of various sectors including production and daily life, the current research and development requirements for new flow measurement equipment are: high rangeability, no pipe-damaging operations during installation, and non-contact flow measurement; high measurement accuracy and reliability, unaffected by fluid impurities, and good environmental adaptability; and low cost to meet the needs of industrial production.

[0059] In conclusion, comparing the development requirements of new flow measurement equipment with the performance parameters of ultrasonic flow meters, it is clear that the development trend of ultrasonic flow meters aligns with that of new flow measurement equipment. With the continuous development of integrated electronic technology, the improvement of sensor performance, and the advancements in various modern high-tech advancements, ultrasonic flow meters will experience significant growth and have a wider range of applications.

[0060] Traditional flow measurement methods, such as orifice plate flow measurement, eddy current flow measurement, and electromagnetic flow measurement, suffer from complex structures, significant pressure loss, high cost, inflexibility, poor accuracy, low adaptability, and small measurement range. These methods are unsuitable for applications requiring limited downhole operating space, complex conditions, and high stability. This application proposes a solution based on ultrasonic flow measurement, utilizing a CTMU (Computer-to-Mechanical Unit) to achieve wide-range, adaptive, and high-precision flow measurement of injected fluids in downhole wells.

[0061] To address the aforementioned deficiencies, this application provides an adaptive variable current source ultrasonic flow measurement method based on a CTMU. The method employs the least squares method to establish a flow velocity influencing factor matrix, a measured flow velocity matrix, a residual variable matrix, and an unmeasured flow matrix. Based on these matrices, a multiple regression equation is established. The unmeasured flow rate of the fluid in the downhole pipeline is then predicted using this multiple regression equation. Alternatively, the sum of squared deviations of the measured flow rate is calculated based on the measured flow velocity and its influencing factors. The unmeasured flow rate is then predicted based on this sum of squared deviations.

[0062] The proposed solution can improve the accuracy of ultrasonic flow measurement and has strong ease of use and practicality.

[0063] The specific process implemented in this application is described below through specific embodiments.

[0064] Please see Figure 1 , Figure 1 This is a schematic diagram illustrating the steps of the adaptive variable current source ultrasonic flow measurement method based on a CTMU provided in this application embodiment. The method is implemented based on an ultrasonic excitation circuit, such as... Figure 1 As shown, the method may include the following steps: S101. Using the least squares method, a matrix of flow velocity influencing factors, a matrix of measured flow velocities, a matrix of residual variables, and a matrix of unmeasured flow rates are established.

[0065] S102. Based on the flow velocity influencing factor matrix, the measured flow velocity matrix, the residual variable matrix, and the unmeasured flow rate matrix, a multiple regression equation is established.

[0066] S103, based on a multiple regression equation, predicts the unmeasured flow rate of fluid in downhole pipelines.

[0067] S104, or, based on the measured flow velocity and the factors affecting the flow velocity, calculate the sum of squared deviations of the measured flow rate.

[0068] S105 predicts unmeasured flow rates based on the sum of squared deviations of measured flow rates.

[0069] It should be noted that steps S101~S103 and steps S104~S105 are parallel technical solutions.

[0070] According to one embodiment of this application, the expression for the flow velocity influencing factor matrix is ​​as follows: Its transpose is , n This indicates the number of factors influencing flow velocity; the expression for the measured flow velocity matrix is: , n Indicates the number of flow velocities that have been measured; The expression for the residual variable matrix is: Its transpose is , k This represents the number of residual variables; the expression for the unmeasured flow matrix is... Its transpose is , m This indicates the number of unmeasured flow rates.

[0071] According to one embodiment of this application, the expression for the multiple regression equation is as follows:

[0072] .

[0073] According to one embodiment of this application, the residual variable is calculated using the following formula:

[0074] in, e k Represents the residual variable. σ k Indicates factors affecting flow velocity. This represents the average of the measured flow velocities. This represents the mean of the factors affecting flow velocity. and Indicates an intermediate variable.

[0075] According to one embodiment of this application, the expression for the sum of squares of deviations of the measured flow rate is as follows: ;

[0076] in, g 2 This represents the sum of squared deviations of the measured flow rates. SSE Represents the sum of squared deviations. e This represents the difference between the measured flow rates. and l 2 Indicates an intermediate variable.

[0077] According to one embodiment of this application, the method further includes: Based on the propagation time of the ultrasound waves in both downstream and upstream directions, the total propagation time of the ultrasound waves is calculated. Based on the total propagation time, the total flow rate of the fluid in the downhole pipeline is then calculated.

[0078] According to one embodiment of this application, the method further includes, in addition to calculating the total propagation time of the ultrasonic wave based on its propagation time in both downstream and upstream currents, the total propagation time of the ultrasonic wave. The propagation time of ultrasound in downstream and upstream currents can be calculated using the following formulas:

[0079]

[0080] Where t1 represents the propagation time of the ultrasonic wave in the downstream direction, t2 represents the propagation time of the ultrasonic wave in the upstream direction, L represents the distance between the two ultrasonic transducers, c represents the propagation speed of the ultrasonic wave entering the ultrasonic transducer, v represents the flow velocity of the fluid in the wellbore, and θ represents the refraction angle of the ultrasonic wave when it enters the wellbore wall from the ultrasonic transducer.

[0081] According to one embodiment of this application, the total propagation time of the ultrasonic wave is calculated based on the propagation time of the ultrasonic wave in the downstream and upstream directions, including: The difference between the propagation time of ultrasound waves in the countercurrent and in the downstream is taken as the total propagation time. The specific calculation formula is as follows:

[0082]

[0083] Where Λt represents the total propagation time.

[0084] According to one embodiment of this application, the total flow rate of fluid in a downhole pipeline is calculated based on the total propagation time, including: The total flow rate of the fluid in the downhole pipeline can be calculated using the following formula: ,

[0085] Where Q represents the total flow rate of fluid in the downhole pipeline, and D represents an intermediate variable.

[0086] According to one embodiment of this application, the ultrasonic excitation circuit includes: The first CTMU module, connected to the pulse transmission module, is used to output transmission signals and receive differential analog signals output by the first ultrasonic transducer. A pulse transmission module, connected to the first comparator, is used to transmit pulse waveforms; The first operational amplifier module is connected to the first ultrasonic transducer and is used to amplify the differential analog signal output by the first ultrasonic transducer. The first comparator, connected to the first operational amplifier module, is used to convert the amplified differential analog signal into a digital signal. The second operational amplifier module is connected to the second ultrasonic transducer and is used to amplify the differential analog signal output by the second ultrasonic transducer. The second comparator, connected to the second operational amplifier module, is used to convert the amplified differential analog signal into a digital signal. The second CTMU module, connected to the second comparator, is used to measure the propagation time of ultrasonic waves in both downstream and upstream directions.

[0087] According to one embodiment of this application, the pulse emission module includes a TTL or CMOS transistor.

[0088] According to one embodiment of this application, the first operational amplifier module or the second operational amplifier module includes: a first-stage operational amplifier and a second-stage operational amplifier.

[0089] According to one embodiment of this application, the circuit further includes: a first analog switch and a second analog switch. A first terminal of the first analog switch is connected to the output terminal of a first ultrasonic transducer, and a second terminal of the first analog switch is connected to the non-inverting input terminal of a first operational amplifier module. A first terminal of the second analog switch is connected to the output terminal of a second ultrasonic transducer, and a second terminal of the second analog switch is connected to the non-inverting input terminal of a second operational amplifier module.

[0090] In some embodiments, during downhole flow measurement, an adaptive algorithm corrects the capacitor charging and discharging rate, altering the capacitor charging and discharging cycle. This allows for flexible adjustment of the current source's current variation trend, extending the capacitor charging time and ensuring that the time difference measured by ultrasound in both downstream and upstream flows falls within the capacitor's charging and discharging cycle. This adaptive algorithm uses a linear regression algorithm to compare the difference between measured and unmeasured flow rates and predict flow. If the unmeasured flow rate is about to reach the capacitor discharge time, the adaptive algorithm adjusts the current source's range, extending the discharge time to ensure the validity of the fluid flow measurement results.

[0091] In the process of measuring the flow rate of injected fluid in downhole wells, due to the long injection time and extremely limited space, the downhole flow rate detection method is required to have a wide measurement range, high flexibility and accuracy. Therefore, this application proposes an adaptive prediction algorithm to solve the problem of the fixed measurement range of the CTMU module, increase its flexibility of use and broaden the range of ultrasonic flow rate measurement.

[0092] In practice, capacitor parameters cannot perfectly match theoretical values. The CTMU module charging time difference measurement method exhibits nonlinear measurement regions at the beginning and near-full charging stages. Therefore, this application proposes a method for measuring the starting position of the linear region, enabling the measurement system to maintain both a wide measurement range and high measurement accuracy.

[0093] Because the signal amplitude of ultrasound waves attenuates significantly when passing through a medium, a strong excitation signal is required, which can affect the signal quality and stability of the system. This application's embodiments utilize the CTMU module of a dsPIC (Digital Signal Controller) to design and study a transceiver-separated ultrasonic detection system. The system is ingeniously designed, low-cost, and flexible in application.

[0094] To achieve wide-range, adaptive, and high-precision measurement of downhole injected fluid, in addition to the aforementioned adaptive algorithm, this application provides a hardware system to support the algorithm. This system includes two transceiver modules, connected to an external ultrasonic transducer. The main control chip is a dsPIC, whose primary function is to output the transmitted signal and receive the differential analog signal output from the ultrasonic transducer.

[0095] Specific circuits such as Figure 2 As shown. When transceiver board 1 outputs a transmit signal, the dsPIC controls the MOS transistor to transmit a pulse waveform. After receiving the signal, transceiver board 2 amplifies and conditions it, then passes it through a comparator circuit to convert the analog signal into a digital signal level, which is then precisely timed by the CTMU module.

[0096] The CTMU time measurement unit is essentially a constant current source. This constant current source charges and discharges the circuit, and then a high-precision ADC is used to measure the capacitor voltage. The voltage magnitude represents the charging time, which is recorded as the time difference. A schematic diagram of its working principle is shown below. Figure 3 As shown, the converted time difference can be expressed as: (1-1) The basic charge differential equation is as follows: A schematic diagram of the CTMU charge / discharge curve is shown below. Figure 4 As shown, the flow rate is directly proportional to the collected voltage value, therefore the flow rate should be linear within the system's measurement range. However, under constant power supply charging, the capacitor's parameters cannot perfectly approximate the theoretical values. This will lead to nonlinear charging processes in the actual charging process within the ranges T0 to T1 and T2 to T3, due to factors such as the capacitor's initial state and impending overflow.

[0097] Therefore, the embodiments of this application greatly improve the accuracy of flow detection by keeping the next measurement value within the linear measurement segment T1 to T2.

[0098] The adaptive algorithm determines the relationship between fluid flow rate and velocity. Given the known charging and discharging time of the capacitor, it analyzes the quantitative relationship between the two variables, calculates the difference between measured flow points, quantitatively analyzes the direction of unmeasured flow, and makes a judgment.

[0099] For example: assuming the flow velocity is Unmeasured flow rate Based on the idea of ​​linear regression, their relationship can be expressed as: (1-2) in, The coefficients are linear. This represents the difference between the measured flow rates.

[0100] However, in actual flow measurement, flow velocity and flow rate do not exhibit a linear relationship, requiring a multiple regression analysis to determine the relationship between the measured flow rate, flow velocity, and unmeasured flow rate. First, the factors influencing flow velocity are established using the least squares method, denoted as [factors related to flow velocity]. The matrix is ​​represented as: Its transpose matrix is ​​represented as The measured flow velocity is Let the measured velocity matrix be . The residual matrix is ​​represented as The transpose matrix is ​​represented as The unmeasured flow matrix is ​​denoted as The transpose matrix is ​​represented as .

[0101] The predicted flow matrix can be represented by the multiple regression equation as follows: = * + (1-3) Expanding equation (1-3) as follows: (1-4) The residual variable matrix can be calculated from the measured flow rate and velocity, using the following formula: (1-5) In addition to the above analysis of unmeasured flow rates, the unmeasured flow rates can also be analyzed by calculating the sum of squared deviations of the measured flow rates. The formula for the sum of squared deviations is: (1-6) in, .

[0102] in, For the measured flow velocity, According to and The estimated unmeasured flow rate.

[0103] The adaptive algorithm proposed in this application is based on the time-difference ultrasonic flow measurement method. It utilizes a pair of ultrasonic transducers that alternately transmit and receive ultrasonic waves in opposite directions, indirectly measuring the fluid velocity by observing the time difference between the downstream and upstream propagation of the ultrasonic waves in the medium. The difference in propagation time between downstream and upstream of the ultrasonic waves within the same propagation path is because the velocity within the same propagation path is the sum of the ultrasonic wave propagation speed and the component of the fluid velocity in the ultrasonic wave propagation direction.

[0104] There are two common detection methods: dual-wedge forward and reverse flow detection and quad-wedge forward and reverse flow detection, such as... Figure 5 As shown. Because the four-voice wedge forward and reverse flow detection method results in inconsistencies between the starting and ending points during forward and reverse flow, making it unreliable, the two-voice wedge forward and reverse flow detection method was chosen.

[0105] The following is the derivation of the formulas for measuring flow rate using ultrasound in both co-current and counter-current flow, with a specific flow-time relationship diagram shown below. Figure 6 As shown. Let the propagation time of the ultrasonic wave in the downstream and upstream directions be respectively... , Then t1 and t2 can be expressed as: (1-7) (1-8) in, This indicates the distance between two transducers. This indicates the propagation speed of ultrasound waves entering the transducer. This indicates the velocity of the fluid flowing in the wellbore. This represents the angle of refraction when the ultrasonic wave travels from the transducer into the wellbore wall. From this, the propagation time of the ultrasonic wave can be deduced as: (1-9) Due to the speed of ultrasonic signal propagation Then equation (1-9) can be rewritten as: (1-10) flow With flow rate The conversions are as follows: (1-11) Based on the actual results, .

[0106] According to one embodiment of this application, the specific implementation scheme is as follows: (1) Analyze the actual water injection flow rate changes, and take the overall trend of experimental flow rate changes as a reference to establish the flow rate injection conditions of first gradually increasing, then maintaining relative stability, and then decreasing. (2) Design an ultrasonic excitation circuit and adjust the transmission power appropriately so that the ultrasonic probe at the receiving end can receive an effective ultrasonic signal; (3) Design a bidirectional measurement system that uses only two ultrasonic probes, and the circuit should be separate for transmitting and receiving to improve measurement accuracy and reliability; (4) Design and construct the water injection test pipeline, arrange the measurement environment, and inject fluid at a constant speed using a controllable water pump according to the injection model to complete the flow measurement process. The water injection test pipeline is as follows: Figure 6 As shown; (5) Adjust the adaptive measurement coefficients; (6) Start the ultrasonic measurement system and begin injecting fluid; (7) Simultaneously record and save the system's direct measurement time, adaptive measurement time, and actual injection flow rate; (8) Calculate the corresponding flow rate by the time difference of ultrasonic propagation in the fluid with and against the flow, and compare it with the actual injection flow rate; (9) By changing the fluid injection speed range, the measurement range and accuracy of the system are repeatedly tested, and the adaptive measurement coefficient is adjusted to make the adaptive algorithm more stable.

[0107] The proposed solution can meet the accuracy requirements of fluid flow measurement, and solves the problems of range overflow and poor accuracy caused by different flow rates by changing the current of the constant current source through an adaptive algorithm. Its CTMU measurement module can achieve the same accuracy measurement with a delay of up to 200µs.

[0108] Please see Figure 7 , Figure 7 This is a schematic diagram of the fluid injection experimental pipeline provided in an embodiment of this application. Figure 7 In the diagram: 6-1 is ultrasonic probe 1, 6-2 is the water inlet, 6-3 is the water outlet, and 6-4 is ultrasonic probe 2.

[0109] like Figure 7 As shown, the fluid injection pipeline consists of ultrasonic probe 1, an injection port, an outlet, and ultrasonic probe 2. The ultrasonic probe is used to collect sound wave signals and converts the sound waves into electrical signals through a built-in circuit. The two ultrasonic probes serve as the receiving probe and the transmitting probe, respectively.

[0110] In one embodiment, when the ultrasonic probe 1 emits, the transmitting circuit emits a pulse signal of a certain power. Sensor 1 converts this signal into a sound wave signal, which is received by the ultrasonic sensor 2 and converted into an electrical signal for processing. When the fluid flow rate is in its rising phase, a model of the fluid flow rate with respect to the flow velocity can be established based on the overall trend of the experiment, reducing the injection conditions for the flow rate. The fluid flow rate model generally exhibits a pattern of first gradually increasing, then stabilizing, and then decreasing. Figure 6 As shown.

[0111] In one embodiment, a water injection test pipeline is designed and constructed by modeling and analyzing the overall fluid flow rate, such as... Figure 7 As shown, an ultrasonic excitation circuit was designed. After appropriately adjusting the transmission power, the ultrasonic probe at the receiving end could receive an effective ultrasonic signal. The designed circuit uses two dsPIC chips, which can be used for transmitting control signals and processing acoustic signals, such as... Figure 2 As shown.

[0112] In some embodiments, when starting the ultrasonic measurement system, it is necessary to record and save the system's direct measurement time, adaptive measurement time, and actual injection flow rate. The experimental steps are as follows: (1) Gradually increase the flow rate to 847.5 cm. 3 / s, saves and records various traffic parameters; (2) Maintain a flow rate of 847.5 cm for a period of time. 3 Save and record various traffic parameters around / s; (3) Gradually reduce the flow rate to 0 and save the record of each flow rate parameter; (4) Compare and analyze the data of direct flow measurement, adaptive flow measurement and actual injection flow to verify the correctness of the adaptive wide range flow measurement method.

[0113] The adaptive variable current source ultrasonic flow measurement method based on CTMU provided in this application adopts the least squares method to establish a flow velocity influencing factor matrix, a measured flow velocity matrix, a residual variable matrix, and an unmeasured flow matrix; based on the flow velocity influencing factor matrix, the measured flow velocity matrix, the residual variable matrix, and the unmeasured flow matrix, a multiple regression equation is established; based on the multiple regression equation, the unmeasured flow rate of the fluid in the downhole pipeline is predicted; or, based on the measured flow velocity and flow velocity influencing factors, the sum of squared deviations of the measured flow rate is calculated; based on the sum of squared deviations of the measured flow rate, the unmeasured flow rate is predicted.

[0114] The proposed solution can improve the accuracy of ultrasonic flow measurement and has strong ease of use and practicality.

[0115] This application proposes a high-precision, wide-range ultrasonic flow measurement method for use in oil and gas well water injection. By employing an adaptive flow prediction method, the performance of the ultrasonic detector is improved, enabling the monitoring of complex and variable fluids downhole.

[0116] This application's solution, through the design of an adaptive variation algorithm combined with a hardware CTMU (Charging Time Measurement Unit) module, ensures that the downhole flow measurement range remains within the effective range of capacitor charging and discharging. Furthermore, it can provide the relationship between the current measurement point and the next measurement point, predict the approximate range of the next measurement point, and make corresponding adjustments. This application's solution effectively improves the accuracy of time-of-flight ultrasonic flowmeter measurements and overcomes the influence of capacitor charging and discharging time on the measurement range.

[0117] It should be understood that the sequence number of each step in the above embodiments does not imply the order of execution. The execution order of each process should be determined by its function and internal logic, and should not constitute any limitation on the implementation process of the embodiments of this application.

[0118] Corresponding to the method in the above embodiments, Figure 8 This is a schematic diagram of the adaptive variable current source ultrasonic flow measurement device based on CTMU provided in the embodiments of this application. For ease of explanation, only the parts relevant to the embodiments of this application are shown.

[0119] Reference Figure 8 As shown in Figure (a), the device includes: The first establishment unit 801 is used to establish the velocity influencing factor matrix, the measured velocity matrix, the residual variable matrix, and the unmeasured flow matrix using the least squares method. The second establishment unit 802 is used to establish a multiple regression equation based on the velocity influencing factor matrix, the measured velocity matrix, the residual variable matrix, and the unmeasured flow matrix. The first prediction unit 803 is used to predict the unmeasured flow rate of fluid in the downhole pipeline based on the multiple regression equation. Reference Figure 8 Figure (b) shows the apparatus comprising: The calculation unit 804 is used to calculate the sum of squares of deviations of the measured flow rate based on the measured flow velocity and the factors affecting the flow velocity; The second prediction unit 805 is used to predict the unmeasured flow rate based on the sum of squared deviations of the measured flow rate.

[0120] It should be noted that the information interaction and execution process between the above-mentioned devices / units are based on the same concept as the method embodiments of this application. For details on their specific functions and technical effects, please refer to the method embodiments section, and they will not be repeated here.

[0121] Those skilled in the art will clearly understand that, for the sake of convenience and brevity, the above-described division of functional units and modules is used as an example. In practical applications, the above functions can be assigned to different functional units and modules as needed, that is, the internal structure of the device can be divided into different functional units or modules to complete all or part of the functions described above. The functional units and modules in the embodiments can be integrated into one processing unit, or each unit can exist physically separately, or two or more units can be integrated into one unit. The integrated unit can be implemented in hardware or as a software functional unit. Furthermore, the specific names of the functional units and modules are only for easy differentiation and are not intended to limit the scope of protection of this application. The specific working process of the units and modules in the above system can be referred to the corresponding process in the foregoing method embodiments, and will not be repeated here.

[0122] Figure 9 This is a schematic diagram of the structure of the electronic device 9 provided in an embodiment of this application. Figure 9 As shown, the electronic device 9 of this embodiment includes: at least one processor 901 ( Figure 9 Only one is shown in the diagram), memory 903, and computer program 902 stored in memory 903 and executable on at least one processor 901, wherein processor 901 executes computer program 902 to implement the steps in the above method embodiments.

[0123] Electronic device 9 can be a desktop computer, laptop, PDA, or mobile phone, etc. This electronic device 9 may include, but is not limited to, a processor 901 and a memory 903. Those skilled in the art will understand that... Figure 9 This is merely an example of electronic device 9 and does not constitute a limitation on electronic device 9. It may include more or fewer components than shown, or combine certain components, or different components, such as input / output devices, network access devices, etc.

[0124] The processor 901 may be a Central Processing Unit (CPU), but it can also be other general-purpose processors, digital signal processors (DSPs), application-specific integrated circuits (ASICs), field-programmable gate arrays (FPGAs), or other programmable logic devices, discrete gate or transistor logic devices, discrete hardware photovoltaic modules, etc. A general-purpose processor can be a microprocessor or any conventional processor.

[0125] In some embodiments, memory 903 may be an internal storage unit of electronic device 9, such as a hard disk or memory of electronic device 9. In other embodiments, memory 903 may be an external storage device of electronic device 9, such as a plug-in hard disk, smart media card (SMC), secure digital card (SD), flash card, etc., equipped on electronic device 9. Furthermore, memory 903 may include both internal and external storage units of electronic device 9. Memory 903 is used to store operating system, application programs, boot loader, data, and other programs, such as program code of computer programs. Memory 903 may also be used to temporarily store data that has been output or will be output.

[0126] If the integrated units described above are implemented as software functional units and sold or used as independent products, they can be stored in a computer-readable storage medium. Based on this understanding, when implementing all or part of the processes in the methods of the above embodiments of this application, it can be accomplished by a computer program instructing related hardware. This computer program can be stored in a computer-readable storage medium, and when executed by a processor, it can implement the steps applied to the method embodiments described above. The computer program includes computer program code, which can be in the form of source code, object code, executable files, or certain intermediate forms. A computer-readable storage medium can include at least: any entity or device capable of carrying computer program code to a computing device / electronic device, a recording medium, a computer memory, a read-only memory (ROM), a random access memory (RAM), an electrical carrier signal, a telecommunication signal, and a software distribution medium, such as a USB flash drive, a portable hard drive, a magnetic disk, or an optical disk. In some jurisdictions, according to legislation and patent practice, a computer-readable storage medium cannot be an electrical carrier signal or a telecommunication signal.

[0127] This application also provides a computer-readable storage medium storing a computer program that, when executed by a processor, implements the steps in the various method embodiments described above.

[0128] This application provides a computer program product that, when run on an electronic device, causes the electronic device to execute the steps described in the various method embodiments above.

[0129] In the above embodiments, the descriptions of each embodiment have different focuses. For parts that are not described in detail or recorded in a certain embodiment, please refer to the relevant descriptions of other embodiments.

[0130] Those skilled in the art will recognize that the units and algorithm steps of the various examples described in conjunction with the embodiments disclosed herein can be implemented in electronic hardware, or a combination of computer software and electronic hardware. Whether these functions are implemented in hardware or software depends on the specific application and design constraints of the technical solution. Those skilled in the art can use different methods to implement the described functions for each specific application, but such implementation should not be considered beyond the scope of this application.

[0131] In the embodiments provided in this application, it should be understood that the disclosed devices / electronic devices and methods can be implemented in other ways. The device / electronic device embodiments described above are merely illustrative, and the division of modules or units described above is only a logical functional division. In actual implementation, there may be other division methods. For example, multiple units or photovoltaic modules may be combined or integrated into another system, and some features may be ignored. Furthermore, the indirect coupling, direct coupling, or communication connection shown or discussed may be through some interfaces, devices, or units, and may be electrical, mechanical, or other forms.

[0132] The units described above as separate components may or may not be physically separate. The components shown as units may or may not be physical units; that is, they may be located in one place or distributed across multiple network units. Some or all of the units can be selected to achieve the purpose of this embodiment according to actual needs.

[0133] The above embodiments are only used to illustrate the technical solutions of this application, and are not intended to limit them. Although this application has been described in detail with reference to the above embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the above embodiments, or equivalent substitutions can be made to some of the technical features. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of this application, and should all be included within the protection scope of this application.

Claims

1. A CTMU-based adaptive variable current source ultrasonic flow measurement method, characterized in that, Based on an ultrasonic excitation circuit, the method includes: The least squares method was used to establish the matrix of factors affecting flow velocity, the matrix of measured flow velocity, the matrix of residual variables, and the matrix of unmeasured flow rate. A multiple regression equation is established based on the flow velocity influencing factor matrix, the measured flow velocity matrix, the residual variable matrix, and the unmeasured flow rate matrix. Based on the aforementioned multiple regression equation, the unmeasured flow rate of fluid in downhole pipelines is predicted; Alternatively, the sum of squares of deviations of the measured flow rate can be calculated based on the measured flow velocity and the factors affecting the flow velocity. Based on the sum of squared deviations of the measured flow rates, the unmeasured flow rates are predicted.

2. The adaptive variable current source ultrasonic flow measurement method based on CTMU according to claim 1, characterized in that, The expression of the flow rate influencing factor matrix is , and its transpose is , n represents the number of flow rate influencing factors. The expression of the measured flow rate matrix is , n denotes the number of measured flow rates; The expression of the residual variable matrix is The transpose of which is , k denotes the number of residual variables; The expression for the unmeasured flow matrix is: Its transpose is , m This indicates the number of unmeasured flow rates.

3. The CTMU-based adaptive variable current source ultrasonic flow measurement method of claim 2, wherein, The expression for the multiple regression equation is as follows: ； 。 4. The CTMU-based adaptive variable current source ultrasonic flow measurement method of claim 2, wherein, The residual variable is calculated using the following formula: in, e k Represents the residual variable. σ k Indicates factors affecting flow velocity. This represents the average of the measured flow velocities. This represents the mean of the factors affecting flow velocity. and Indicates an intermediate variable.

5. The CTMU-based adaptive variable current source ultrasonic flow measurement method of claim 2, wherein, The expression for the sum of squared deviations of the measured flow rate is as follows: ； in, g 2 This represents the sum of squared deviations of the measured flow rates. SSE Represents the sum of squared deviations. e This represents the difference between the measured flow rates. and l 2 Indicates an intermediate variable.

6. The CTMU-based adaptive variable current source ultrasonic flow measurement method of claim 1, wherein, The method further includes: The total propagation time of the ultrasound is calculated based on the propagation time of the ultrasound in both downstream and upstream directions. The total flow rate of the fluid in the downhole pipeline is calculated based on the total propagation time.

7. The CTMU-based adaptive variable current source ultrasonic flow measurement method of claim 6, wherein, The method, which calculates the total propagation time of ultrasound waves based on their propagation times in both upstream and downstream directions, further includes: The propagation time of ultrasound in downstream and upstream currents can be calculated using the following formulas: in, t 1 represents the propagation time of ultrasound waves in the downstream direction. t 2 indicates the propagation time of ultrasound waves in the countercurrent. L This indicates the distance between two ultrasonic transducers. c This indicates the propagation speed of ultrasound waves entering the ultrasonic transducer. v This indicates the flow velocity of the fluid in the wellbore. θ This indicates the angle of refraction when an ultrasonic wave travels from the ultrasonic transducer into the well casing wall.

8. The adaptive variable current source ultrasonic flow measurement method based on CTMU according to claim 7, characterized in that, Based on the propagation time of ultrasound in both upstream and downstream directions, the total propagation time of ultrasound is calculated, including: The difference between the propagation time of ultrasound waves in the countercurrent and in the downstream is taken as the total propagation time, and the specific calculation formula is as follows: in, Λt Indicates the total propagation time.

9. The adaptive variable current source ultrasonic flow measurement method based on CTMU according to claim 8, characterized in that, Based on the total propagation time, the total flow rate of the fluid in the downhole pipeline is calculated, including: The total flow rate of the fluid in the downhole pipeline can be calculated using the following formula: ， in, Q This indicates the total flow rate of fluid in the downhole pipeline. D Indicates an intermediate variable.

10. The adaptive variable current source ultrasonic flow measurement method based on CTMU according to any one of claims 1-9, characterized in that, The circuit includes: The first CTMU module, connected to the pulse transmission module, is used to output transmission signals and receive differential analog signals output by the first ultrasonic transducer. A pulse transmission module, connected to the first comparator, is used to transmit pulse waveforms; The first operational amplifier module is connected to the first ultrasonic transducer and is used to amplify the differential analog signal output by the first ultrasonic transducer. The first comparator, connected to the first operational amplifier module, is used to convert the amplified differential analog signal into a digital signal. The second operational amplifier module is connected to the second ultrasonic transducer and is used to amplify the differential analog signal output by the second ultrasonic transducer. The second comparator, connected to the second operational amplifier module, is used to convert the amplified differential analog signal into a digital signal. The second CTMU module, connected to the second comparator, is used to measure the propagation time of ultrasonic waves in both downstream and upstream directions.

11. The adaptive variable current source ultrasonic flow measurement method based on CTMU according to claim 10, characterized in that, The pulse emission module includes a TTL or CMOS transistor.

12. The adaptive variable current source ultrasonic flow measurement method based on CTMU according to claim 10, characterized in that, The first operational amplifier module or the second operational amplifier module includes: a first-stage operational amplifier and a second-stage operational amplifier.

13. The adaptive variable current source ultrasonic flow measurement method based on CTMU according to claim 10, characterized in that, The circuit also includes: a first analog switch and a second analog switch; The first terminal of the first analog switch is connected to the output terminal of the first ultrasonic transducer, and the second terminal of the first analog switch is connected to the non-inverting input terminal of the first operational amplifier module. The first terminal of the second analog switch is connected to the output terminal of the second ultrasonic transducer, and the second terminal of the second analog switch is connected to the non-inverting input terminal of the second operational amplifier module.

14. An electronic device comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, characterized in that, When the processor executes the computer program, it implements the adaptive variable current source ultrasonic flow measurement method based on any one of claims 1-9.

15. A computer-readable storage medium storing a computer program, characterized in that, When the computer program is executed by the processor, it implements the adaptive variable current source ultrasonic flow measurement method based on CTMU as described in any one of claims 1-9.

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