WO2018030919A1 - Method for determining the site of a leak in a pipeline and device for the implementation thereof - Google Patents

Abstract

The group of inventions relates to a method and device for determining the site of a liquid or gas leak in a pipeline and is intended to determine the coordinates of leaks at difficult-to-access sites in pipelines such as gas pipelines and oil pipelines. The technical result of the claimed group of inventions is a more accurate and reliable determination of the site of a leak in a pipeline. The present method for determining the site of a leak in a pipeline includes the following steps: forced excitation of acoustic vibrations in a pipeline, to which two acoustic sensors are secured at a set distance from one another along the length of the pipeline; reception of acoustic pulse signals by the first and second acoustic sensors, the time of arrival of the acoustic pulses being registered first at the first, near acoustic sensor and then at the second acoustic sensor; determination of the average group velocity of the sound propagation of an acoustic signal in the pipeline on the basis of data about the passage of acoustic pulse signals from a means for generating acoustic signals to at least one acoustic sensor; reception, by the first and second acoustic sensors, of an acoustic signal from a leak, and subsequent processing of the received signal and determination of the time delay of arrival of the signal at a sensor from the leak; determination of the distance to the leak in the pipeline from one of the sensors on the basis of the calculated time delay of arrival of the signal at the sensor from the leak and the measured average group velocity of the sound propagation of an acoustic signal in the pipeline.

Description

 METHOD FOR DETERMINING A LEAK PLACE IN A PIPELINE

 AND DEVICE FOR ITS IMPLEMENTATION

FIELD OF TECHNOLOGY

 The group of inventions relates to a method and apparatus for determining the location of a leak of liquid or gas in pipelines and is intended to determine the coordinates of a leak in hard-to-reach places of a pipeline, for example, gas pipelines and oil pipelines.

 BACKGROUND

 A known method for detecting the location of a leak disclosed in US 5058419 A, publ. 10/22/19991. The method consists in receiving sound by the first sensor installed on the pipeline, receiving a signal by the second sensor installed on the same pipeline at a distance from the first, performing mathematical processing of the signals, calculating the delay time of the signal from the leak, determining the distance to the leak from the first and second sensors .

 This correlation method has several disadvantages. To calculate the distance to the leak, it is necessary to know the value of the velocity of the group velocity of sound in the pipeline with the liquid. In this patent, this speed is determined by calculation, which can lead to significant errors in determining the distance to the leak. With an error in determining the speed of 5%, the error in determining the distance in a pipeline with a length of 1000 m can reach ± 5 0 m, which is not acceptable for earthworks in urban conditions.

 The closest analogue of the claimed group of the invention is a method and device for determining the location of a leak in a pipeline, disclosed in RU 22498020 C2, publ. 04/10/2005.

The method disclosed in the closest analogue consists in receiving noise signals by the first and second acoustic sensors, converting these acoustic signals into electrical ones, filtering and sampling the electrical signals and determining the leak location by the delay time of the noise leak signals, while the acoustic sensors are installed side by side, one on the pipeline, the second next to the pipeline in the environment, the first sensor is shielded from noise in the environment, the second sensor is shielded from noise in the pipeline. First, at a fixed distance R _H from the sensors, an artificial noise signal is excited in the pipeline and in its environment, a noise signal propagating through the pipeline by the first acoustic sensor is received, a noise signal propagating through the environment by the second acoustic sensor, electrical signals of the first and second acoustic sensors after filtering and sampling, they are subjected to inter-spectral processing, according to the data on the real and imaginary parts of the mutual spectrum, the value of R _H and the calculated value of the propagation velocity of acoustic waves in the medium find the propagation velocity group waves in the pipeline, in the presence of a leak signal, perform the inter-spectral processing of the filtered, discretized leak signals converted to electrical signals received by the first and second acoustic sensors, the delay time of the noise leak signals received by the first and second acoustic sensors, determine data on the real and imaginary parts of the mutual spectrum of noise leak signals, after which the leak location is determined taking into account the propagation velocity of acoustic waves in the medium and the velocity of group waves in the pipeline. This group velocity value is used to calculate the distance to the leak.

 The device for determining a leak in a pipeline, disclosed in the closest analogue, contains first and second receiving paths, each of which contains series-connected first and second acoustic sensors, respectively, an amplifier, a filter, an analog-to-digital converter, the first acoustic sensor having acoustic contact with piping and is acoustically shielded from acoustic waves in the environment of the conduit, and a second acoustic is acoustically shielded from acoustic waves propagating through the pipeline, a mutual spectrum analyzer is introduced into the device, the first and second inputs of which are connected to the outputs of the analog-to-digital converters of the first and second receiving paths, respectively, a unit for calculating the distance and propagation velocity of group waves in the pipeline and an indicator, a memory unit is also introduced the propagation velocities of group waves in the pipeline and in the surrounding medium, the input of which is connected to the second output, and the output to the second input of the block computing states and propagation velocities of group waves in the pipeline, a control unit has also been introduced, the sync inputs and sync outputs of which are connected to an analog-to-digital converter, with a mutual spectrum analyzer, with a unit for calculating the distance and propagation velocity of group waves in a pipeline, with a memory unit for propagation velocities of group waves in the pipeline and in the surrounding pipeline environment and with an indicator, an artificial source of acoustic signal is also introduced, acoustically connected to the first acoustic sensor m through the pipeline, and with a second acoustic sensor through the environment surrounding the pipeline.

 The disadvantages of the closest analogue is the low accuracy in determining the distance to the leak for the following reasons:

- accurate determination of the speed of sound in the environment is a difficult task and setting a tabular value for a given speed or calculating it has large deviations from the true value and lead to the same errors in determining the group velocity as simply calculating from a given diameter, pressure and material. - a noise source of artificial sound complicates the determination of the signal transit time and increases the error in its determination. In addition, if the environment surrounding the pipeline is soil, then attenuation of the acoustic signal in the soil will not allow the use of this device in practice, because the distance from the source of the artificial source of the acoustic signal to the location of the sensors will not exceed several meters.

 - hardware errors in measuring the delay time, matching the start time of the pulse in the soil and the pipeline, the inaccuracy of setting the speed of sound in the environment will lead to tens of percent errors in calculating the group velocity of sound in the pipeline.

 SUMMARY OF THE INVENTION

 The objective of the claimed group of inventions is to develop a method and device for determining the location of a leak in the pipeline, ensuring the accuracy of determining the location of a leak in the pipeline.

 The technical result of the claimed group of inventions is to increase the accuracy and reliability of determining the location of a leak in the pipeline.

 The specified technical result is achieved due to the fact that the method of determining the place of a leak in the pipeline includes the following steps:

 a) Forced excitation of acoustic vibrations in the pipeline, on which two acoustic sensors are fixed, located at a given distance from each other along the length of the pipeline;

 b) Reception of acoustic pulsed signals by the first and second acoustic sensors, with fixing the time of arrival of acoustic pulses, first to the first acoustic sensor - the near one, and then to the second acoustic sensor;

 c) Determining the average group velocity of sound propagation of the acoustic signal in the pipeline based on the passage of acoustic pulse signals from the means for generating acoustic signals to at least one acoustic sensor;

 d) Acceptance of the acoustic signal from the leak by the first and second acoustic sensors, followed by processing the received signal and determining the time delay for the signal to arrive at the sensors from the leak;

 e) Determining the distance to the leak in the pipeline from one of the sensors based on the determined time delay of the signal to the sensors from the leak and the measured average group sound velocity in the pipeline.

The forced excitation of acoustic vibrations in the pipeline is carried out at a predetermined distance from the means for generating acoustic signals to the first acoustic sensor, and the average group velocity of sound propagation of the acoustic signal is determined based on the travel time the acoustic signal from the means for generating acoustic signals to the first acoustic sensor, which is the receiver of the acoustic signal from the means for creating acoustic signals to determine the speed of sound.

 The acoustic waves are forcedly excited in the pipeline at a predetermined distance from the acoustic signal generating means to the first acoustic sensor, and the average group velocity of sound propagation of the acoustic signal is determined based on the acoustic signal propagation time between the first and second acoustic sensors, with the first and second acoustic sensors are correlation and receivers of the acoustic signal from the means for creating acoustic signals for determining the speed of sound.

 Forced acoustic vibrations in the pipeline are carried out at an unknown distance from the acoustic signal generating means to the first acoustic sensor, and the average group velocity of sound propagation of the acoustic signal is determined based on the acoustic signal propagation time between the first and second acoustic sensors, while the first and second acoustic sensors are correlation and receivers of the acoustic signal from the means for creating acoustic signals for I determine the speed of sound.

 Forced excitation of acoustic vibrations in the pipeline is carried out using an acoustic pulse generator connected to means for generating acoustic signals by mechanical shock on the surface of the pipeline.

 Forced excitation of acoustic vibrations in the pipeline is carried out using an acoustic pulse generator connected to means for generating acoustic signals by creating an acoustic signal by a piezo emitter and transmitting the signal through a waveguide to the surface of the pipeline.

The specified technical result is also achieved due to the fact that the device for determining the location of the leak in the pipeline for the implementation of the above method contains an acoustic pulse generator, first and second receiving paths, each of which contains an acoustic sensor, amplifier, filter, signal transmission means, signal receiving means and an analog-to-digital converter (ADC) connected to the processing unit to which the indicator is connected, while the acoustic generator pulse signals connected to the means of generating acoustic signals installed on the pipeline and creating acoustic vibrations in the pipeline, while the first and second acoustic sensors located on the pipeline are spaced apart by a predetermined the distance along its length is acoustically connected by means of a pipeline with a means of creating acoustic signals.

 As a means of creating acoustic signals, a mechanical percussion device driven by a solenoid is used.

 As a means of creating acoustic signals, a piezoelectric emitter acoustically connected to the pipeline is used.

 The means for creating acoustic signals is located in one housing with the first acoustic sensor.

 Means for transmitting and receiving a signal are made as a radio transmitter and receiver of a radio signal.

 Means of signal transmission and reception are made in the form of a wired connection.

 The acoustic pulse generator is provided with a pulse time synchronization means connected to the processing unit.

 Means for synchronizing the time of the pulse connected to the processing unit using wired communication.

 Means for synchronizing the time of the pulse connected to the processing unit via a radio channel.

 BRIEF DESCRIPTION OF THE DRAWINGS

 The invention will be more clear from the description, which is not restrictive and given with reference to the accompanying drawings, which depict:

 FIG. 1 - Block diagram of the device;

 FIG. 2 - Location on the pipeline of the elements of the device.

 1 - the first acoustic sensor; 2 - second acoustic sensor; 3 - amplifier; filter; 4 - filter; 5 - signal transmission means; 6 - means for receiving a signal; 7 - ADC; 8 - processing unit; 9 - indicator; 10 - generator of acoustic pulse signals; 11 - means for creating acoustic signals; 12 - place of leak in the pipeline.

 DETAILED DESCRIPTION OF THE INVENTION

The device for determining the location of the leak in the pipeline for implementation contains a generator (10) of acoustic pulse signals, the first and second receiving paths, each of which contains a series-connected acoustic sensor (1, 2), amplifier (3), filter (4), means ( 5) signal transmission, signal receiving means (6) and an analog-to-digital converter (7) connected to the processing unit (8) to which the indicator (9) is connected, while the generator (10) of acoustic pulse signals is connected to the means (1) 1) create acoustic si channels installed on the pipeline and creating acoustic vibrations in the pipeline, while the first (1) and second (2) acoustic sensors located on the pipeline are spaced a predetermined distance along its length, are acoustically connected by means of the pipeline to the means (1 1) of creating acoustic signals. As a means (1 1) of creating acoustic signals, a mechanical shock device is used driven by a solenoid.

 As a means (11) for generating acoustic signals, a piezoelectric emitter acoustically connected to the pipeline is used.

 The acoustic signal generating means (1 1) is located in the same housing as the first (1) acoustic sensor.

 Means of transmission (5) and reception (6) of the signal are made as a radio transmitter and receiver of the radio signal.

 Means of transmission (5) and reception (6) of the signal are made in the form of a wired connection. The generator (10) of acoustic pulse signals is equipped with means for synchronizing the time of the pulse connected to the processing unit.

 Means for synchronizing the time of the pulse connected to the processing unit using wired communication.

 Means for synchronizing the time of the pulse connected to the processing unit via a radio channel.

The claimed device in accordance with FIG. 1 -2 works as follows. In accordance with one embodiment of the invention, means (1 1) for generating an acoustic signal, first (1) and second (2) acoustic sensors are fixed along the length of the pipeline, while means (1 1) for creating an acoustic signal are fixed to the pipeline at a predetermined distance mn (up to 1 km) from the first (1) - near acoustic sensor, and the first (1) and second (2) acoustic sensors are also fixed on the pipeline at a given distance n ₂ (up to 1 km). Then, acoustic vibrations are forcedly excited in the pipeline; for this, the acoustic pulse generator (10) is connected to the acoustic signal generating means (11) made in the form of a mechanical shock device or a piezoelectric emitter. After that, the generator (10) of acoustic pulse signals generates a voltage or current pulse, which is supplied to the means (1 1) for creating an acoustic signal and after converting the signal into it, means (11) for creating an acoustic signal are acoustically connected to the pipeline. In this case, the generator (10) of acoustic pulse signals contains means for synchronizing the time of the pulse, which records the start time of the creation of the acoustic signal and transfers it to the processing unit (8). The acoustic signal generating means (11) acoustically creates an acoustic signal in the pipeline, which, propagating through the pipeline, is detected by the first acoustic sensor (1), amplified in the amplifier (3), filtered by the filter (4), and transmitted using the signal transmission means (5) to the signal receiving means (6), the ADC is digitized (7), and enters the processing unit (8). The acoustic signal, reaching the second acoustic sensor (2) located at a given distance from the first (1), is fixed by it and after processing similar to that described above, it enters the processing unit (8). In the processing unit (8), the average group velocity (Vrp) of the signal propagation is calculated based on the delay time of the acoustic signal propagation between the sensors (t2) and the known distance between the sensors (h2) according to the formula:

 Vrp = h2 \ t2

 After that, the forced excitation of acoustic vibrations in the pipeline is stopped, while the first (1) and second (2) acoustic sensors detect acoustic continuous signals from a leak, the received signals are amplified in an amplifier (3), filtered by a filter (4), and using transmission means of the signal (5) are transmitted to the signal receiving means (6), the ADCs are digitized (7), and fed to the processing unit (8). In the processing unit (8), correlation processing of the processed continuous signals is carried out, with the detection of signals from the leak. Based on the correlation processing, the delay time of the signal from the leak to the first (1) and second (2) acoustic sensors is determined. Based on the delay time of the signal from the leak to the first (1) and second (2) acoustic sensors and the average group speed, the processing unit calculates the distance to the leak from one of the sensors. The calculated data are displayed on the indicator (9).

 The use of two acoustic sensors (1, 2) located at a given distance from each other along the length of the pipeline and means (1 1) for creating an acoustic signal located at a given distance from the first (1) - near acoustic sensor allows to increase the accuracy and reliability of determining the location finding leaks in the pipeline, due to the location of the means (1 1) for creating an acoustic signal from the first (1) - nearest acoustic sensor at a greater distance than in the closest analogue, since in the closest However, when creating acoustic vibrations in the soil, the source of generating acoustic vibrations can be installed no more than 10 m from the acoustic sensor, since the acoustic signal in the soil decays quickly and it is difficult to accurately determine the average group velocity of the signal, therefore, the proposed group EFFECT: invention makes it possible to more accurately determine the average group velocity of a signal, therefore, to increase the accuracy and reliability of determining the location of a leak in a pipeline.

In accordance with another embodiment, in which acoustic signal generating means (11) are fixed along the pipe length, the first (1) and second (2) acoustic sensors, while acoustic signal generating means (11) are fixed to the pipeline at an unknown distance mn ( up to 1 km) from the first (1) - near acoustic sensor, and the first (1) and second (2) acoustic sensors are also fixed on the pipeline at a given distance n ₂ (up to 1 km). The operation of the device is carried out similarly to the first embodiment of the invention, for except that the average group signal propagation speed is determined based on the acoustic signal transit time between the first (1) and second (2) acoustic sensors, and the acoustic pulse generator (10) does not include a pulse time synchronization means.

 The implementation of the claimed group of inventions according to the second embodiment, using acoustic sensors spaced apart by a predetermined distance on the pipeline (1, 2), in contrast to the prototype, improves the accuracy and reliability of determining the location of a leak in the pipeline, due to a more accurate determination of the group velocity of the signal in pipeline by measuring it in the same section of the pipeline, where the leak location is determined by the correlation method.

 Thus, the proposed group of the invention improves the accuracy and reliability of determining the location of a leak in the pipeline.

 The invention has been disclosed above with reference to a specific embodiment. For specialists, other embodiments of the invention that are not changing its essence, as disclosed in the present description, may be obvious. Accordingly, the invention should be considered limited in scope only by the following claims.

Claims

CLAIM  one . A method for determining the location of a leak in a pipeline, comprising the following steps:  a) Forced excitation of acoustic vibrations in the pipeline, on which two acoustic sensors are fixed, located at a given distance from each other along the length of the pipeline;  b) Reception of acoustic pulsed signals by the first and second acoustic sensors, with fixing the time of arrival of acoustic pulses, first to the first acoustic sensor - the near one, and then to the second acoustic sensor;  c) Determining the average group velocity of sound propagation of the acoustic signal in the pipeline based on the passage of acoustic pulse signals from the means for generating acoustic signals to at least one acoustic sensor;  d) Acceptance of the acoustic signal from the leak by the first and second acoustic sensors, followed by processing the received signal and determining the time delay for the signal to arrive at the sensors from the leak;  e) Determining the distance to the leak in the pipeline from one of the sensors based on the determined time delay of the signal to the sensors from the leak and the measured average group sound velocity in the pipeline.  2. The method according to p. 1, characterized in that the forced excitation of acoustic vibrations in the pipeline is carried out at a predetermined distance from the means for generating acoustic signals to the first acoustic sensor, and the average group velocity of sound propagation of the acoustic signal is determined based on the transit time of the acoustic signal from the means creating acoustic signals to the first acoustic sensor, which is the receiver of the acoustic signal.  3. The method according to p. 1, characterized in that the forced excitation of acoustic vibrations in the pipeline is carried out at a predetermined distance from the means for generating acoustic signals to the first acoustic sensor, and the average group velocity of sound propagation of the acoustic signal is determined based on the transit time of the acoustic signal between the first and the second acoustic sensors, while the first and second acoustic sensors are correlation and receivers of the acoustic signal from means and creating acoustic signals to determine the speed of sound. 4. The method according to p. 1, characterized in that the forced excitation of acoustic vibrations in the pipeline is carried out at an unknown distance from the means for creating acoustic signals to the first acoustic sensor, and the determination of the average group velocity of sound propagation of the acoustic signal carried out on the basis of the travel time of the acoustic signal between the first and second acoustic sensors, while the first and second acoustic sensors are correlation and receivers of the acoustic signal from the means for generating acoustic signals to determine the speed of sound.  5. The method according to any one of p. 1, 2, 3 or 4, characterized in that the forced excitation of acoustic vibrations in the pipeline is carried out using an acoustic pulse generator connected to means for generating acoustic signals by mechanical shock on the surface of the pipeline.  6. The method according to any one of p. 1, 2, 3 or 4, characterized in that the forced excitation of acoustic vibrations in the pipeline is carried out using an acoustic pulse generator connected to means for generating acoustic signals by creating an acoustic signal by a piezo emitter and transmitting the signal through waveguide to the surface of the pipeline.  7. A device for determining the location of a leak in a pipeline for implementing the method according to claims 1 to 6, comprising an acoustic pulse generator, first and second receiving paths, each of which contains an acoustic sensor, amplifier, filter, signal transmission means, connected in series, signal receiving means and an analog-to-digital converter connected to the processing unit to which the indicator is connected, while the acoustic pulse generator is connected to the means for generating acoustic signals installed on the pipeline and creating acoustic vibrations in the pipeline, while the first and second acoustic sensors located on the pipeline are spaced a predetermined distance along its length, are acoustically connected by means of the pipeline to the means for generating acoustic signals.  8. The device according to p. 7, characterized in that as a means of creating acoustic signals applied mechanical shock device, driven by a solenoid.  9. The device according to claim 7, characterized in that a piezoelectric emitter acoustically connected to the pipeline is used as a means of generating acoustic signals.  10. The device according to p. 7, characterized in that the means for creating acoustic signals is located in one housing with the first acoustic sensor.  eleven . The device according to claim 7, characterized in that the means of transmission and reception of the signal are made as a radio transmitter and receiver of the radio signal. 12. The device according to p. 1 1, characterized in that the means of transmission and reception of the signal are made in the form of a wired connection. 13. The device according to claim 7, characterized in that the acoustic pulse generator is equipped with a pulse time synchronization means connected to the processing unit.  14. The device according to p. 13, characterized in that the means for synchronizing the time of the pulse of the generator of acoustic vibrations connected to the processing unit using a wired connection.  15. The device according to p. 13, characterized in that the means of synchronizing the time of the pulse of the generator of acoustic oscillations connected to the processing unit via a radio channel.