STM32-based sand production erosion monitoring system

Abstract

An STM32-based sand production erosion monitoring system comprises a control logic part, the control logic part comprises a sand production erosion monitoring circuit using STM32F407ZGT6 as a main control chip, and the main control chip is responsible for controlling ultrasonic wave transmitting and receiving and sand production signal acquisition and calculating abrasion of a pipe wall caused by sand impact on a pipeline and the sand production amount in real time; according to the erosion monitoring part, the emitted ultrasonic waves pass through the pipe wall of the to-be-measured pipeline, echo waves are collected through a pulse reflection method and transmitted to a main control chip for erosion thickness calculation; the sand production monitoring part is used for collecting sand production signals and transmitting the sand production signals to the main control chip for sand production amount calculation; the data storage part is used for storing the collected sand production signal data; the communication part is used for transmitting the sand production amount and the erosion thickness calculated by the main control chip to a PC (Personal Computer) end by using an RS485; according to the utility model, the sand production amount and the pipe wall erosion thickness are monitored, the sand production condition of an oil and gas well and the pipeline erosion condition can be monitored at the PC end, and the system has a real-time monitoring function, stable performance and high precision.

Description

Technical Field

[0001] The utility model relates to the field of oil and gas well exploitation technology and ultrasonic technology, and particularly relates to a sand erosion monitoring system based on STM32. Background Art

[0002] The main methods for monitoring sand production in oil and gas wells include acoustic wave detection method, ER detection method, and fiber optic acoustic wave detection method. The acoustic wave detection method uses a piezoelectric sensor to detect the ultrasonic signal generated by the collision of sand particles and oil and gas pipes. The intensity of the detected signal is used to calculate the sand content in the fluid using a certain algorithm. According to the installation method of the sensor, it can be divided into two types: built-in and external. However, it cannot detect the erosion of the pipe wall caused by sand particles. The ER (Electrical Resistance) detection method is also called the resistance monitoring method. The ER monitoring method uses a built-in method. The sensor is inserted into the oil and gas pipe. The sand production in the oil and gas pipe is identified by the wear caused by the impact of sand particles on the metal probe of the sensor. This method requires drilling holes in the monitored pipeline to install sensors, and the service life of the probe is limited, which is detrimental to the normal production and safety of gas wells. The fiber optic acoustic wave detection method is to monitor the sand content in the fluid by a sensor array. The sensor array is composed of an acoustic sensor and an optical fiber. The acoustic sensor is composed of one or more acoustic wave sensing areas, and the sensing area contains one or more hydrophones. The hydrophone forms the optical fiber at a certain interval through a Bragg grating. These gratings have the ability to selectively reflect predetermined wavelengths. The optical signal in the optical fiber is transmitted and received by the optical transceiver, and the light intensity change monitored by the hydrophone is analyzed to identify whether the fluid contains sand. For example, the invention with patent application number CN201910640351.1 is the fiber optic acoustic wave detection method. The use of distributed optical fiber sound monitoring can realize distributed and real-time sand production status monitoring of all production layers; the degree of sand production in each layer can be qualitatively judged; temporary monitoring of sand production in the well can be realized; and the evaluation of sand prevention effect of sand production layers can be realized. However, this detection method is relatively complicated and costly. Therefore, it is particularly important to develop a new detection method or equipment. Summary of the invention

[0003] In order to solve the above technical problems, the purpose of the utility model is to provide a sand erosion monitoring system based on STM32, in which an ultrasonic transceiver integrated sensor and an acceleration sensor are fixed at twice the diameter of the outer wall of the elbow of the oil and gas well pipeline through a clamp. Since the position is a sensitive area where sand particles collide with the pipe wall, at this position, both the sand content of the fluid in the pipeline and the erosion caused by the sand particles hitting the pipeline can be monitored. At the same time, the sand production and erosion thickness can be remotely monitored in real time without destroying the structural integrity of the pipeline. The system has low cost, is easy to implement, and has high detection accuracy.

[0004] In order to achieve the above object, the technical solution of the utility model is implemented as follows:

[0005] A sand production erosion monitoring system based on STM32, comprising: a PC terminal 1, an RS485 communication module 2, a control logic module 3, an ultrasonic transmitting circuit 4, an ultrasonic transceiver integrated transducer 5, an ultrasonic receiving circuit 6, an acceleration sensor 7, a sand production signal receiving circuit 8, and a data storage circuit 9;

[0006] The PC terminal 1 displays the sand production amount and erosion thickness data calculated by the control logic module 3 on the PC terminal interface to monitor the sand production amount and erosion thickness in real time;

[0007] The RS485 communication module 2 converts the USB level of the PC terminal 1 and the TTL level of the control logic module 3 into RS485 level for communication;

[0008] The control logic module 3, which is the STM32F407ZGT6 minimum system, is responsible for controlling ultrasonic transmission and reception and collecting sand production signals, and is used to calculate the wear of the pipe wall caused by sand grains hitting the pipe and the sand production amount in real time;

[0009] The ultrasonic transmitting circuit 4 converts the signal transmitted by the control logic module 3 into an excitation signal and transmits it to the ultrasonic transceiver integrated transducer 5;

[0010] The ultrasonic transceiver integrated transducer 5, that is, a transducer with an integrated ultrasonic transmitting end and receiving end, is used to transmit and receive ultrasonic waves;

[0011] The ultrasonic receiving circuit 6 transmits the ultrasonic echo signal received by the ultrasonic transceiver integrated transducer 5 to the control logic module 3;

[0012] The acceleration sensor 7 converts the vibration signal generated by sand grains hitting the pipe wall into an electrical signal;

[0013] The sand production signal receiving circuit 8 transmits the sand production signal received by the acceleration sensor 7 to the control logic module 3, and uses the ADC peripheral in the control logic module 3 to collect the sand production signal;

[0014] The data storage circuit 9 stores the collected sand production signal data.

[0015] The ultrasonic transmitting circuit 4 includes an excitation signal transmitting circuit 12, a power amplification circuit 10 connected to the excitation signal transmitting circuit 12, and a drive voltage amplification circuit 11. The function of the power amplification circuit 10 is to amplify the COMS level of the PWM square wave signal transmitted by the control logic module 3 for the field effect transistor IRF840 of the excitation signal transmitting circuit 12. The function of the drive voltage amplification circuit 11 is to output a +48V voltage from the input +24V voltage through the DC-DC chip XL6019. The function of the excitation signal transmitting circuit 12 is to control the field effect transistor IRF840 of the excitation signal transmitting circuit 12 to cut off the PWM square wave signal transmitted by the control logic module 3, so that the capacitor C52 of the excitation signal transmitting circuit 12 is charged to reach the DC high voltage of the drive voltage amplification circuit 11, and then by controlling the conduction of the field effect transistor IRF840 of the excitation signal transmitting circuit 12, the capacitor C52 of the excitation signal transmitting circuit 12 is discharged to generate an excitation ultrasonic emission signal.

[0016] The ultrasonic receiving circuit 6 includes a limiting circuit 13, an impedance matching circuit 14, a voltage-controlled gain amplification circuit 15, a band-pass filter circuit 16, a differential amplification circuit 17, an AD acquisition circuit 18, an output buffer circuit 19, and a buffer control circuit 20 connected in sequence. The specific circuit function of the limiting circuit 13 is to protect the receiving circuit and limit the receiving end voltage to ±0.75V. The impedance matching circuit 14 is used to improve the load-carrying capacity, and its output voltage is not affected by the impedance of the subsequent circuit. The voltage-controlled gain amplification circuit 15 is used to amplify the ultrasonic echo signal received by the ultrasonic transceiver integrated transducer 5. The band-pass filter circuit 16 is used to filter out noise signals and improve the signal-to-noise ratio. The differential amplification circuit 17 is used to enable the AD acquisition circuit 18 to adopt a differential input method to improve the anti-interference ability and achieve the best dynamic performance of the AD acquisition circuit 18. The AD acquisition circuit 18 is used to convert the ultrasonic echo analog signal received by the ultrasonic transceiver integrated transducer 5 into a digital signal through AD sampling. The output buffer circuit 19 is used to provide a buffer for the ultrasonic echo data output by the AD acquisition circuit 18 and the ultrasonic echo data received by the control logic module 3. The sampling frequency of the AD acquisition circuit 18 is synchronized with the write clock of the output buffer circuit 19, and the control logic module 3 is synchronized with the read clock of the output buffer circuit 19. The buffer control circuit 20 is used to provide the write clock frequency of the output buffer circuit 19 and the sampling clock frequency of the AD acquisition circuit 18 for the source crystal oscillator X4, and the NAND gate chip SN74S00N and the high and low levels output by the I / O pins of the control logic module 3 control the reset, read and write operations of the output buffer circuit 19 and the sampling clock frequency of the AD acquisition circuit 18.

[0017] The sand production signal receiving circuit 8 specifically includes a charge amplification circuit 21, a low-pass filter circuit 22, and a conversion voltage circuit 23 connected in sequence. The charge amplification circuit 21 amplifies the sand production information received by the acceleration sensor 7. The low-pass filter circuit 22 filters out high-frequency noise signals using a second-order low-pass filter and retains the sand production signal. The conversion voltage circuit 23 converts the sand production signal voltage from -12V to +12V to 0 to +3.3V, which is consistent with the ADC acquisition voltage range inside the control logic module 3.

[0018] Compared with the prior art, the advantages of the present utility model are as follows:

[0019] 1. The control logic module 3 uses the STM32F407 as the main control chip, which is responsible for controlling the ultrasonic emission and reception and the acquisition of sand production signals, and is used to calculate in real time the wear of the pipe wall caused by sand particles hitting the pipe and the sand production volume, realizing the dual monitoring of sand production and erosion.

[0020] 2. The drive voltage amplification circuit 11 in the ultrasonic emission circuit 4 outputs an amplified voltage through the DC-DC chip XL6019, and the excitation signal emission circuit 12 generates an excitation ultrasonic emission signal, so that the subsequent ultrasonic transceiver integrated transducer 5 can obtain high data accuracy.

[0021] In summary, the present utility model can not only monitor the sand content in the fluid in the pipe but also monitor the erosion situation caused by sand particles hitting the pipe. At the same time, it can perform real-time remote monitoring of the sand production volume and erosion thickness without damaging the structural integrity of the pipe. The whole system has a simple structure, simple monitoring, low cost, is easy to implement, has high detection accuracy, and is suitable for large-scale popularization and use. Description of the Drawings

[0022] Figure 1 It is a schematic diagram of the overall design scheme of a sand production and erosion monitoring system based on STM32 provided by the present utility model.

[0023] Figure 2 It is a system block diagram of the ultrasonic emission circuit provided by the embodiment of the present utility model.

[0024] Figure 3 It is a system block diagram of the ultrasonic reception circuit provided by the embodiment of the present utility model.

[0025] Figure 4 It is a system block diagram of the sand production signal receiving module provided by the embodiment of the present utility model.

[0026] Figure 5 It is a power amplification circuit diagram of the ultrasonic emission circuit provided by the embodiment of the present utility model.

[0027] Figure 6The circuit diagram of the drive voltage amplification in the ultrasonic emission circuit provided by the embodiment of the present utility model.

[0028] Figure 7 The circuit diagram of the excitation signal emission in the ultrasonic emission circuit provided by the embodiment of the present utility model.

[0029] Figure 8 The circuit diagram of the amplitude limiting in the ultrasonic receiving circuit provided by the embodiment of the present utility model.

[0030] Figure 9 The circuit diagram of the impedance matching in the ultrasonic receiving circuit provided by the embodiment of the present utility model.

[0031] Figure 10 The circuit diagram of the voltage-controlled gain amplification in the ultrasonic receiving circuit provided by the embodiment of the present utility model.

[0032] Figure 11 The circuit diagram of the band-pass filtering in the ultrasonic receiving circuit provided by the embodiment of the present utility model.

[0033] Figure 12 The circuit diagram of the differential amplification in the ultrasonic receiving circuit provided by the embodiment of the present utility model.

[0034] Figure 13 The circuit diagram of the AD acquisition in the ultrasonic receiving circuit provided by the embodiment of the present utility model.

[0035] Figure 14 The circuit diagram of the output buffer in the ultrasonic receiving circuit provided by the embodiment of the present utility model.

[0036] Figure 15 The circuit diagram of the buffer control in the ultrasonic receiving circuit provided by the embodiment of the present utility model.

[0037] Figure 16 The circuit diagram of the charge amplification in the sand production signal receiving module provided by the embodiment of the present utility model.

[0038] Figure 17 The circuit diagram of the low-pass filtering in the sand production signal receiving module provided by the embodiment of the present utility model.

[0039] Figure 18 The circuit diagram of the conversion voltage in the sand production signal receiving module provided by the embodiment of the present utility model.

[0040] Figure 19 The circuit diagram of the STM32F407ZGT6 minimum system in the control logic module provided by the embodiment of the present utility model.

[0041] Figure 20The circuit diagram of the RS485 communication module provided for the embodiment of the present utility model.

[0042] Figure 21 The circuit diagram of the data storage provided for the embodiment of the present utility model.

[0043] Figure 22 The equivalent circuit diagram of the drive voltage amplification circuit in the ultrasonic emission circuit.

[0044] Figure 23 The software flowchart of the sand production erosion monitoring system based on STM32.

[0045] Figure 24 The structural schematic diagram of the actual monitored sand production amount and erosion thickness. Specific implementation manners

[0046] Next, the technical solutions in the embodiments of the present utility model will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present utility model.

[0047] See Figure 1 , the figure shows a sand production erosion monitoring system based on STM32 provided for the embodiment of the present utility model, and the system includes: a PC terminal 1, an RS485 communication module 2, a control logic module 3, an ultrasonic emission circuit 4, an ultrasonic transceiver integrated transducer 5, an ultrasonic reception circuit 6, an acceleration sensor 7, a sand production signal reception circuit 8, and a data storage circuit 9;

[0048] The PC terminal 1 displays the sand production amount and erosion thickness data calculated by the control logic module 3 on the PC terminal interface to monitor the sand production amount and erosion thickness in real time;

[0049] The circuit diagram of the RS485 communication module 2 is as shown in Figure 20 , and it converts the USB level of the PC terminal 1 and the TTL level of the control logic module 3 into RS485 level through the RS485 communication module 2 for communication;

[0050] The circuit diagram of the control logic module 3 is as shown in Figure 19 , which is the minimum system of STM32F407ZGT6, responsible for controlling the ultrasonic emission and reception and the acquisition of sand production signals, and is used to calculate the wear of the pipe wall caused by sand grains hitting the pipe and the sand production amount in real time;

[0051] The ultrasonic emission circuit 4 is as shown in Figure 2 , and specifically includes a power amplification circuit 10, a drive voltage amplification circuit 11, and an excitation signal emission circuit 12, which converts the signal emitted by the control logic module 3 into an excitation signal and transmits it to the ultrasonic transceiver integrated transducer 5;

[0052] The ultrasonic transceiver integrated transducer 5, that is, a transducer with an integrated ultrasonic transmitting end and receiving end, is used to transmit and receive ultrasonic waves;

[0053] The ultrasonic receiving circuit 6 is as Figure 3 shown, and specifically includes a limiter circuit 13, an impedance matching circuit 14, a voltage-controlled gain amplifier circuit 15, a band-pass filter circuit 16, a differential amplifier circuit 17, an AD acquisition circuit 18, an output buffer circuit 19, and a buffer control circuit 20, and transmits the ultrasonic echo signal received by the ultrasonic transceiver integrated transducer 5 to the control logic module 3;

[0054] The acceleration sensor 7. When sand grains impact the pipe wall, vibration signals will be generated, and the generated vibration signals are converted into electrical signals through the acceleration sensor 7;

[0055] The sand production signal receiving circuit 8 is as Figure 4 shown, and specifically includes a charge amplifier circuit 21, a low-pass filter circuit 22, and a conversion voltage circuit 23, and transmits the sand production signal received by the acceleration sensor 7 to the control logic module 3, and uses the ADC peripheral in the control logic module 3 to collect the sand production signal;

[0056] The data storage circuit 9 is as Figure 21 shown. The storage chip K9K8G08U0M in the data storage circuit 9 has a flash memory capacity of 8 Gbit and a spare space of 256 Mbit, which is sufficient to store the collected sand production signal data.

[0057] Figure 5 is the power amplifier circuit diagram in the ultrasonic transmitting circuit. Its specific circuit function is to convert the CMOS level of the PWM square wave signal transmitted by the control logic module 3 into a signal with a high level of +10V and a low level of 0V by the power amplifier chip MC34152, which is specially designed to drive a high-conversion-rate large capacitive load with a low-current digital signal, for exciting the field effect transistor IRF840 of the signal transmitting circuit 12. Since the maximum input voltage of the M34152 chip does not exceed 2.6V, the resistors R20 and R53 play a voltage-dividing role for the input PWM square wave signal, and its capacitor C51 filters out the AC high-frequency components of the PWM square wave after power amplification.

[0058] Figure 6 is the drive voltage amplifier circuit diagram in the ultrasonic transmitting circuit. Its specific circuit function is to output a voltage of +48V from the +24V voltage through the DC-DC chip XL6019. Due to the switching characteristics of the DC-DC chip and its operation in the discontinuous mode, the output voltage pin of the chip is connected to the input voltage +24V, which is equivalent to raising the potential of the output pin of the chip XL6019 to +24V. Therefore, the output voltage of the chip is 72V, and then it is doubled to a DC high voltage of +144V through the charge pump circuit. The equivalent circuit diagram of the DC-DC chip is asFigure 22 As shown, the switching node SW is an AC source. Assume the output voltage of the DC-DC chip is V0 and the diode has no voltage drop. Due to the unidirectional conductivity of diode D32, the potentials at points B and C are clamped to V0. When the switch is open, since the voltage across capacitor C5 cannot change suddenly, the potential at point C becomes 2V0, and at the same time, C113 is charged, and the potential at point D is also 2V0. When the switch is closed, capacitor C5 discharges. When the potential at point C is less than 2V0, D34 is reverse non-conductive, keeping the potential at point D at 2V0 unchanged. In actual situations, capacitors C112, C116, C113 and diodes D31, D32, D34 in the charge pump circuit will have a certain voltage drop. Finally, the input voltage is +24V, and the DC high voltage output through the drive voltage amplification circuit is 118V.

[0059] Figure 7 It is the excitation signal emission circuit diagram in the ultrasonic emission circuit. Its specific circuit function is to drive the power field-effect transistor IRF840 through the power amplification circuit 10 for the PWM square wave signal emitted by the control logic module 3. When the PWM square wave is at a low level, the power field-effect transistor IRF840 is in a cut-off state, and the high voltage generated by the drive voltage amplification circuit 11 can only form a loop through capacitor C52 and fast recovery diode D3, and after a certain time, the two ends of capacitor C52 are kept at the DC high voltage generated by the drive voltage amplification circuit 11. When the PWM square wave is at a high level, the field-effect transistor IRF840 conducts, and capacitor C52 discharges. Since the voltage across the capacitor cannot change suddenly, and at the same time, in order to make Figure 7 only negative high-voltage spikes appear at point A in, fast recovery diode D4 is added. At the moment when IRF840 conducts, the ultrasonic emission end obtains a negative high-voltage spike for discharging, and this excitation signal is used to excite the ultrasonic transceiver integrated transducer 5 to emit ultrasonic waves. To make the transducer reach the best state, there is an optimal relationship between the duty cycle of the excitation signal PWM square wave and the transducer, as shown in formula (8)

[0060]

[0061] In formula (8), f 0 is the probe frequency, 2a is the emission pulse width, n is usually taken as 1. The PWM square wave signal emitted by the control logic module (3) needs to correspond to the center frequency of the ultrasonic transceiver integrated transducer through formula (8). To make the ultrasonic detection of the erosion thickness of sand grains hitting the pipeline have high accuracy, the smaller the resistance R19, the shorter the vibration time of the transducer wafer, and the greater the detection resolution.

[0062] Figure 8It is the limiter circuit diagram in the ultrasonic receiving circuit. Its specific circuit function is to limit the voltage of the negative high-voltage spike signal at the transmitting end of the transducer in the ultrasonic echo signal received by the ultrasonic transceiver integrated transducer 5 within a certain range to protect the receiving circuit. Capacitor C67 functions to filter DC signals. The resistance value of R35 is large enough compared to the resistance value of R19 in the excitation transmitting circuit to eliminate the load effect generated by the receiving circuit on the transmitting circuit. Diodes D5 and D6 limit the voltage at the receiving end to ±0.75V.

[0063] Figure 9 It is the impedance matching circuit diagram in the ultrasonic receiving circuit. Its specific circuit function is to utilize the characteristics of high input impedance and low output impedance of its voltage follower to improve the load-carrying capacity, and its output voltage is not affected by the impedance of the subsequent circuit.

[0064] Figure 10 It is the voltage-controlled gain amplifier circuit diagram in the ultrasonic receiving circuit. Its specific circuit function is to amplify the ultrasonic echo signal received by the ultrasonic transceiver integrated transducer 5. Its gain is controlled by the output voltage of the DAC peripheral pin inside the control logic module 3. The maximum gain is controlled by resistors R70 and R71. The DAC peripheral pin inside the control logic module 3 is connected to the gain control pin VG of the VCA821DGST chip, and the input voltage of the DAC is 0 - 2V. Due to the impedance matching problem between the control logic module 3 and the VCA821DGST chip, the output buffer of the DAC peripheral of the intelligent control logic module 3 is used to reduce the output impedance, so that it is not necessary to add an external operational amplifier to directly drive the voltage-controlled gain amplifier.

[0065] Figure 11 It is the band-pass filter circuit diagram in the ultrasonic receiving circuit, which is a second-order band-pass active filter. Its specific circuit function is to filter out noise signals, making the ultrasonic echo signal received by the ultrasonic transceiver integrated transducer 5 more distinguishable and improving the signal-to-noise ratio. This circuit needs to meet the requirements of the emission frequency band range of the ultrasonic transceiver integrated transducer 5 to determine the center angular frequency ω 0 , quality factor Q, as shown in formulas (9) and (10);

[0066]

[0067] Among them, in formula (11) A 0 =R 26 / R 25 , by determining ω 0 and Q value, the bandwidth of the passband ω BH =ω 0 / Q. The present invention sets the bandwidth of the circuit to be 1.592 MHz to 6.366 MHz through Figure 11 circuit.

[0068] Figure 12 It is the differential amplifier circuit diagram in the ultrasonic receiving circuit. The specific function of this circuit is to enable the AD acquisition circuit 18 to adopt a differential input mode, improve the anti-interference ability, while maintaining good linear performance of the signal source, achieve a lower required signal swing allowance, have more margin in the interface circuit, and minimize even harmonics, which helps to achieve the best dynamic performance of the AD acquisition circuit 18.

[0069] Figure 13 It is the AD acquisition circuit diagram in the ultrasonic receiving circuit. The specific function of this circuit is to collect the continuous echo signals of ultrasonic waves received by the ultrasonic transceiver integrated transducer 5 into discrete echo signals through the 12-bit AD chip ADS807E. To avoid the inability to recognize the echo signals collected by ultrasonic waves, the sampling frequency should be at least 3 - 8 times the center frequency of ultrasonic waves. The present utility model adopts a sampling frequency of 50 MHz, and the sampling frequency is provided by the active crystal oscillator in the buffer control circuit (20). The measurement range of the AD acquisition circuit is -1.5V to +1.5V.

[0070] Figure 14 It is the output buffer circuit diagram in the ultrasonic receiving circuit. The specific function of this circuit is that since the data reception rate of the control logic module 3 is less than the sampling clock frequency of the AD acquisition circuit 18, a high-speed cache chip is required to cache the data. In this circuit, the write clock frequency and the read clock frequency need to be provided separately. Among them, the write clock frequency needs to be consistent with the clock frequency of the AD acquisition circuit 18, and the write clock frequency is provided by the active crystal oscillator in the buffer control circuit 20. The read clock frequency needs to be consistent with the clock frequency of the control logic module 3. Here, the read clock frequency uses the timer interrupt function in the control logic module 3, and the I / O pin of the control logic module 3 is flipped at a frequency of 1 MHz to simulate the read clock of the cache chip to achieve the purpose of clock synchronization, so as to read the correct data. The cache chip needs to be power-on reset before asynchronously reading data. If the storage space of the cache chip is full of written data, the chip write full flag pin will output a low level; when all the data is read, there is no data to be read in the cache chip, and the chip read empty flag will output a low level. Since the AD chip ADS807E of the AD acquisition circuit 18 is a 12-bit AD, and the output buffer circuit chip CYC7C460A is a 9-bit data input and output, here two output buffer chips CYC7C460A are connected in cascade to the output AD acquisition circuit 17 with 12-bit data.

[0071] Figure 15It is the circuit diagram of buffer control in the ultrasonic receiving circuit. The active crystal oscillator with a frequency of 50 MHz and the NAND gate chip SN74S00N are used. The active crystal oscillator X4 provides the write clock frequency of the output buffer circuit 19 and the sampling clock frequency of the AD acquisition circuit 18. The high and low levels output by the I / O pins of the NAND gate chip SN74S00N and the control logic module 3 control the reset, read and write operations of the output buffer circuit 19 and the sampling clock frequency of the AD acquisition circuit 18.

[0072] Figure 16 It is the circuit diagram of charge amplification in the sand production signal receiving module. The specific circuit function is that since the signal received by the acceleration sensor when the sand grains impact the pipe wall is very weak, especially when the pipe wall is thicker, the received signal may even be at the microvolt level. Therefore, the sand production signal needs to be amplified.

[0073] Figure 17 It is the circuit diagram of low-pass filtering in the sand production signal receiving module. Its specific circuit function is to filter out high-frequency noise signals using second-order low-pass filtering and retain the sand production signal. The frequency of the sand production signal generally does not exceed 500 KHz. The low-pass cut-off frequency f here is set as shown in formula (11);

[0074]

[0075] Since the frequency of the sand production signal increases with the increase of speed, Figure 17 the bandwidth of the sand production frequency band in the circuit is set to 0 - 750 KHz, leaving a certain bandwidth.

[0076] Figure 18 It is the circuit diagram of voltage conversion in the sand production signal receiving module of the present utility model. Its specific circuit function is to convert the sand production signal voltage from -12V to +12V to 0 to +3.3V, which is consistent with the ADC acquisition voltage range inside the control logic module 3, so as to correctly acquire the sand production signal voltage. The conversion formulas are shown in formulas (12) and (13);

[0077]

[0078] Figure 23It is the software flowchart of the sand production erosion monitoring system based on STM32. Since the sand production volume is monitored in real time, the erosion thickness monitoring is interrupted through the control logic module 3 and monitored once every hour. The principle is that the sand production sensor continuously collects sand production signals. After one hour of collection, a cubic spline interpolation function (Spline) is used to fit the curve three times, and then the sand production volume is calculated through formula (6). Since the control logic module 3 sets an interruption every hour, the PWM square wave is emitted from the PC6 pin of the control logic module 3. First, it reads whether the PC6 pin is at a high level. If the PC6 pin is at a high level, then it determines whether the echo signal received by the ultrasonic transceiver integrated transducer 5 exceeds the range of the AD acquisition circuit 18. If it exceeds the range, the DAC output voltage is reduced and then it determines whether it exceeds the range of the AD acquisition circuit 18. If it does not exceed the range of the AD acquisition circuit 18, the AD acquisition clock and the cache chip write clock are enabled through the NAND gate chip SN74S00N in the cache control circuit 20 and the control logic module 3. Then, it determines the write full flag of the cache chip CYC7C460A in the output cache circuit (19) Whether it is 0. If it is not 0, it waits for the write full flag all the time If it is 0, if it is 0, the AD acquisition clock and the cache chip write clock are turned off through the NAND gate chip SN74S00N and the control logic module 3. Then, the cache chip CYC7C460A read clock is enabled through the NAND gate chip SN74S00N and the control logic module 3. Then, it determines the read empty flag of the cache chip CYC7C460A Whether it is 0. If it is not 0, it waits all the time If it is 0 If it is 0, the collected ultrasonic echo signal is fitted with a cubic spline interpolation function (Spline) curve to calculate the transit time Δt. Finally, the sand grain erosion pipe wall thickness is calculated by formula (7).

[0079] Figure 24 It is a schematic diagram of the actual monitored sand production volume and erosion thickness structure. 24 is the pipeline to be measured, 25 is the clamp, 26 is the acceleration sensor, 27 is the ultrasonic transceiver integrated sensor, and the sand production erosion monitoring system of 28 includes Figure 1 The RS485 communication module 2, the control logic circuit 3, the ultrasonic transmitting circuit 4, the ultrasonic receiving circuit 6, the sand production signal receiving circuit 8, and the data storage circuit 9 in it. The ultrasonic transceiver integrated sensor and the acceleration sensor are fixed at twice the diameter of the outer wall of the elbow of the oil and gas well pipeline through the clamp. This position is the sensitive area where the sand grains collide with the pipe wall.

[0080] The working principle of the present utility model includes the following steps:

[0081] (1). Fix the ultrasonic transceiver integrated transducer 5 and the acceleration sensor 7 at the position of twice the diameter on the outer wall of the elbow of the oil and gas well pipeline by means of a clamp. Since this position is a sensitive area where sand grains collide with the pipe wall, the sand content in the fluid in the pipeline and the erosion caused by sand grains hitting the pipeline can be monitored at this position.

[0082] (2). Calculation of the sand production volume; there is a certain relationship between the voltage of the output signal of the acceleration sensor 7 and the kinetic energy of the sand grains. Assuming that all sand grain particles have the same mass and velocity in the experiment, the average power of the sand production signal can be obtained through equations (1) to (3).

[0083]

[0084] In equation (1), β is the sensor sensitivity coefficient, M is the total mass of sand grains hitting the pipe wall, V is the velocity of sand grains, and T is the observation time;

[0085]

[0086] In equation (2), Q is the fluid volume flow rate, and A is the cross-sectional area of the pipeline;

[0087] By substituting equation (2) into equation (substitution, the average power of the sand production signal is given by equation (3);

[0088]

[0089] In addition, according to Parseval's theorem, the sand production signal can be expressed as equation (4);

[0090]

[0091] Δt is the sampling frequency of the analog-to-digital converter, U is the sand production signal collected by the acceleration sensor. Since the collected sand production signal is discrete and the acceleration sensor monitors the sand production signal continuously, a continuous sand production signal is obtained through fitting with a cubic spline interpolation function, expressed as equation (5);

[0092]

[0093] An equation is established between equation (3) and equation (5) to calculate the sand production volume, expressed as equation (6);

[0094]

[0095] During the experiment, since the cross-sectional area A of the pipeline is determined, the fluid volume flow rate Q can be measured by a flowmeter, and the value of β can be calibrated through experiments, so the sand production volume can be measured.

[0096] Secondly, it is the calculation of the erosion thickness. The ultrasonic transceiver integrated probe emits ultrasonic waves through the pipe wall. Take the difference between the maximum peak value of the second echo received by the ultrasonic transceiver integrated probe and the maximum peak value of the first echo

[0097] as the transit time Δt, and calculate the thickness of the sand particle eroded pipe by the pulse reflection method, which is expressed as Equation (7);

[0098]

[0099] where C is the propagation speed of ultrasonic waves in the pipe wall and d is the pipe wall thickness. Since the continuous echo signals received by the ultrasonic transceiver integrated are also discrete echo signals obtained through analog-to-digital (AD) acquisition, if the difference between the maximum peak value of the second echo and the maximum peak value of the first echo acquired by AD is used as the transit time Δt, it will affect the accuracy. Here, the cubic spline interpolation function is also used to interpolate and fit the discrete echo signals acquired by AD to obtain the maximum peak values of the first and second echoes and the transit time Δt. During the experiment, since the speed of ultrasonic waves in the pipe wall is known, the erosion thickness can be measured.

[0100] In summary, the sand production erosion monitoring system of the present utility model simultaneously monitors the sand production volume and the pipe wall erosion thickness, and can monitor the sand production situation and the pipeline erosion situation of the oil and gas well at the PC end, and has a real-time monitoring function. The system performance is stable and the accuracy is high.

[0101] The technical principle of the present utility model has been described above in combination with specific embodiments, and it is not used to limit the present utility model. However, the protection scope of the present utility model is not limited thereto. Any person skilled in the art in the technical field disclosed by the present utility model can easily think of changes or substitutions, which should all be covered within the protection scope of the present utility model. Therefore, the protection scope of the present utility model shall be subject to the protection scope of the claims.

Claims

1. A sand erosion monitoring system based on STM32, characterized in that: include: PC terminal (1), RS485 communication module (2), control logic module (3), ultrasonic transmitting circuit (4), ultrasonic transceiver integrated transducer (5), ultrasonic receiving circuit (6), acceleration sensor (7), sand output signal receiving circuit (8) and data storage circuit (9); The PC end (1) receives the sand production and erosion thickness data calculated by the control logic module (3) and displays them on the PC end interface, thereby monitoring the sand production and erosion thickness in real time; The RS485 communication module (2) converts both the USB level of the PC end (1) and the TTL level of the control logic module (3) into RS485 level for communication; The control logic module (3), which is a minimum system of STM32F407ZGT6, is responsible for controlling the transmission and reception of ultrasonic waves and the collection of sand discharge signals, and is used to calculate in real time the wear of the pipe wall caused by sand particles impacting the pipe and the amount of sand discharged; The ultrasonic transmitting circuit (4) converts the signal emitted by the control logic module (3) into an excitation signal and transmits it to the ultrasonic transceiver integrated transducer (5); The ultrasonic transceiver integrated transducer (5), i.e. a transducer with an ultrasonic transmitting end and a receiving end integrated, is used to transmit and receive ultrasonic waves; The ultrasonic receiving circuit (6) transmits the ultrasonic echo signal received by the ultrasonic transceiver integrated transducer (5) to the control logic module (3); The acceleration sensor (7) converts the vibration signal generated by the sand particles hitting the pipe wall into an electrical signal; The sand generation signal receiving circuit (8) transmits the sand generation signal received by the acceleration sensor (7) to the control logic module (3), and uses the ADC peripheral in the control logic module (3) to collect the sand generation signal; The data storage circuit (9) stores the collected sand production signal data.

2. According to the STM32-based sand erosion monitoring system of claim 1, it is characterized in that: The ultrasonic transmitting circuit (4) comprises an excitation signal transmitting circuit (12), and a power amplifier circuit (10) and a driving voltage amplifier circuit (11) connected to the excitation signal transmitting circuit (12). The power amplifier circuit (10) is used to amplify the power of the COMS level of the PWM square wave signal emitted by the control logic module (3) for the field effect transistor IRF840 of the excitation signal transmitting circuit (12); the driving voltage amplifier circuit (11) is used to amplify the input +24V voltage through the DC-DC chip XL601 9, the voltage at output is +48V, and the function of the excitation signal transmitting circuit (12) is to control the field effect tube IRF840 of the excitation signal transmitting circuit (12) to be cut off by the PWM square wave signal emitted by the control logic module (3), so that the capacitor C52 of the excitation signal transmitting circuit (12) is charged to reach the DC high voltage of the driving voltage amplifier circuit (11), and then the field effect tube IRF840 of the excitation signal transmitting circuit (12) is controlled to be turned on, so that the capacitor C52 of the excitation signal transmitting circuit (12) is discharged, thereby generating an excitation ultrasonic transmitting signal.

3. The STM32-based sand erosion monitoring system according to claim 1 is characterized in that: The ultrasonic receiving circuit (6) comprises a limiting circuit (13), an impedance matching circuit (14), a voltage-controlled gain amplifier circuit (15), a bandpass filter circuit (16), a differential amplifier circuit (17), an AD acquisition circuit (18), an output buffer circuit (19) and a buffer control circuit (20) which are connected in sequence; the limiting circuit (13) has a specific circuit function of protecting the receiving circuit so that the voltage at the receiving end is limited to ±0.75V; the impedance matching circuit (14) has a specific circuit function of improving the load capacity, and its output voltage is not affected by the impedance of the subsequent circuit; the voltage-controlled gain amplifier circuit (15) has a specific circuit function of amplifying the ultrasonic echo signal received by the ultrasonic transceiver integrated transducer (5); the bandpass filter circuit (16) has a specific circuit function of filtering out noise signals and improving the signal-to-noise ratio; the differential amplifier circuit (17) has a specific circuit function of making the AD acquisition circuit (18) adopt a differential input mode to improve the anti-interference performance and realize the AD acquisition circuit (18) optimal dynamics; AD acquisition circuit (18), whose specific circuit function is to convert the ultrasonic echo analog signal received by the ultrasonic transceiver integrated transducer (5) into a digital signal through AD sampling; output buffer circuit (19), whose specific circuit function is to provide buffer for the ultrasonic echo data output by the AD acquisition circuit (18) and the ultrasonic echo data received by the control logic module (3), the sampling frequency of the AD acquisition circuit (18) is synchronized with the write clock of the output buffer circuit (19), and the read clock of the control logic module (3) is synchronized with the output buffer circuit (19); the buffer control circuit (20) is used to provide the write clock frequency of the output buffer circuit (19) and the sampling clock frequency of the AD acquisition circuit (18) for the source crystal oscillator X4, and the high and low levels output by the NAND gate chip SN74S00N and the I / O pin of the control logic module (3) control the reset and read and write operations of the output buffer circuit (19) and the sampling clock frequency of the AD acquisition circuit (18).

4. The STM32-based sand erosion monitoring system according to claim 1 is characterized in that: The sand production signal receiving circuit (8) specifically comprises a charge amplifier circuit (21), a low-pass filter circuit (22) and a voltage conversion circuit (23) which are connected in sequence. The charge amplifier circuit (21) has a specific circuit function of amplifying the sand production information received by the acceleration sensor (7); the low-pass filter circuit (22) has a specific circuit function of filtering out high-frequency noise signals by using a second-order low-pass filter to retain the sand production signal; and the voltage conversion circuit (23) has a specific circuit function of converting the sand production signal voltage -12V to +12V to 0 to +3.3V, which is consistent with the ADC acquisition voltage range inside the control logic module (3).

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