RU2691779C1 - Pulse-acoustic method of determining the location of an in-pipe cleaning tool in a main pipeline - Google Patents

Abstract

FIELD: physics.SUBSTANCE: use to determine location of in-pipe cleaning equipment in main pipeline. Summary of invention consists in the fact that generation and sending from a predetermined point of measurement on a main pipeline pulse acoustic probing signals, receiving an acoustic echo pulse reflected from an in-tube projectile, measurement of time interval τ from the moment of sending the probing pulse to the moment of receiving the echo pulse and determining the distance R from the measurement point to the in-tube projectile from the condition R=Vτ/2, where V is sound velocity in main pipeline environment, wherein before generating acoustic probing signals, further measuring the acoustic noise spectrum in the main pipe, the carrying frequency of the acoustic probing signals is selected outside the frequency spectrum of the main pipe acoustic noise, generation and reception of acoustic signals is carried out using acoustic transmitters and receivers, respectively, installed on main pipeline, after receiving reflected echo pulses determine time τ their delay relative to probing signal by correlation and threshold processing of received echo signals.EFFECT: possibility of increasing efficiency of measuring the location of an in-tube projectile in a main pipeline while maintaining the required accuracy of measuring the position of the projectile in the pipe and eliminating the need to open the pipe for said measurements.4 cl, 2 dwg

Description

The invention relates to the field of construction and operation of main pipelines, in particular to methods for detecting the location of cleaning or diagnostic projectiles inside oil and gas pipelines.

Known methods and means of determining the location of in-shell projectiles SSVS-001 TU 4389-001-39145393-2001 NPF TORI, OJSC Transsibneft (the journal Pipeline Transportation of Oil No. 12, 2003), allowing to determine the location of intratubal shells during their movement in the pipeline in real time by the method of generating, recording, recognizing, analyzing and processing the acoustic signal generated by an acoustic emitter mounted on an in-tube projectile propagating in the working medium — oil — along the pipeline and received by an acoustic sensor with a primary conversion module, communicated with the processing module and transmitting the signal via the transmission line of information and control signals to the central computer in the control room.

These methods and tools are designed for use on pipelines and are based on measuring the characteristics of an acoustic signal propagating in a liquid medium in one direction from the radiator to the sensor.

The main disadvantages of these methods and tools are as follows:

- the need to use specialized in-line projectiles with installed on them the equipment for generating an acoustic signal and the installation of autonomous power sources (batteries);

- with a long stay of the projectile inside the pipeline, the amplitude of the signal emitted by it decreases as the battery discharges, which imposes restrictions on the duration of the projectile tracking in the pipeline.

Known methods and means of determining the location of in-line shells based on the installation on the pipeline of multiple ultrasonic receivers - signaling devices / RU 2408815 / the fact that the projectile passes through the pipeline.

The main disadvantage of these methods and means is that they determine only the fact of the passage of the projectile at the installation site of the sensor. Since the projectile travels considerable distances inside the pipeline, and the place of the possible stopping (sticking) of the projectile is random, a large number of signaling devices / RU 2408815 / must be used to search for the exact location of the projectile.

Known jet-acoustic method of measuring distances (RU 2032183), which consists in the fact that from the measurement source sent to the object directional radiation, receive the signal reflected from the object and the parameters of the signal parameters judge the distance between the emitter and the object, and as a measuring radiation use acoustic oscillations, self-excited at the end of the nozzle and carried by air flowing out of it, which falls on the object and excites, at the point of incidence, multifrequency acoustic oscillations, asprostranyayuschiesya in space from objects in the form of spherical waves arriving at the receiver, and enhance the signal measured in a sliding time interval of the total power, having a decreasing exponential dependence on the length of the jet, and on the average power value of the signal is judged on the distance between the nozzle and the object.

A device for implementing the method comprises a cylindrical nozzle connected to a pneumatic circuit, a receiver in the form of various types of microphones or piezoelectric transducers, a preamplifier, a power amplifier.

The disadvantage of this method is the impossibility of measuring distances when you stop the in-tube projectile, since the formation of the jet is carried out during the movement of the in-tube projectile.

Known mpulsno-acoustic method / EN 2307978 /, allowing to determine the location of the in-line cleaning projectile in the main pipeline with sufficient accuracy.

The specified pulse-acoustic method / EN 2307978 / determine the location of the in-line cleaning projectile in the main pipeline consists in generating and sending pulsed acoustic probe signals from a predetermined measuring point on the main pipeline, measuring the echo pulse reflected from the in-tube, measuring the time interval τ from the moment the probe is sent impulse until the moment of receiving the echo impulse and determining the distance R from the measurement point to the in-line projectile from the condition R = V⋅τ / 2, where V is the speed of sound in the medium of the main pipeline.

At this point, the measurement of the distance R to the in-line projectile is the end of the pipe at the place of the in-tube projectile launch, an acoustic impulse is generated by pulsing a portion of compressed air to the supercritical pressure into the cavity of the main pipeline in the direction of the in-line projectile air and the process of pulsed air supply, take in place of measurement by a pressure receiver installed on the end cap boprovoda acoustic pulse reflected from intratrumpet projectile identify it as a wave momentary pressure increase that propagates with a velocity of sound, thus measure the time interval from the time of sending the acoustic pulse until the reception of the reflected acoustic impulse and determining the distance from the measuring point to an in-tube shell.

Device / RU 2307978 / for pulse-acoustic positioning of the in-tube projectile in the main pipeline contains an acoustic impulse generator and a pressure receiver installed on the end-cap of the pipeline. The acoustic pulse generator is made electromechanical and contains a double-acting pneumatic cylinder, a valve in the form of a valve with a shank, a movable plunger, two springs, through which the plunger interacts with the housing and the shank. The pneumatic cylinder piston is made integral with the plunger, and the cylinder is integral with the body. The pneumatic valve is equipped with an electromagnetic actuator, an electric contact pressure switch and a plate installed at the free end of the shank and combined with the valve of the pneumatic valve.

The technical problem of the known method of pulse-acoustic determination of the location of the in-line projectile in the main pipeline is the need to open the pipeline for measurements and, as a result, reduced search performance of the stuck in-tube projectile associated with increased time spent for measurements and determining its location.

The task and the technical result of the invention is to improve the performance of measurements of the location of the in-line projectile in the main pipeline while maintaining the required accuracy of measuring the position of the projectile in the pipe and eliminating the need to open the pipe for these measurements.

The essence of the invention.

The solution of the task and the achievement of the stated technical result is ensured by the fact that the pulse-acoustic method for determining the location of the in-line cleaning projectile in the main pipeline includes generating and sending pulsed acoustic probing signals from the specified measurement point on the main pipeline, receiving an acoustic echo pulse reflected from the in-line shell, measuring the gap time τ from the moment of sending the sounding ultrasonic signal to the moment of reception echo signal and determining the distance R from the measurement site to the in-tube projectile from the condition R = V⋅τ / 2, where V is the speed of sound in the medium of the main pipeline. According to the invention, before generating acoustic sounding signals, the spectrum of acoustic noise in the main pipe is additionally measured. The carrier frequency of acoustic sounding signals is chosen in the range of carrier frequencies from 300 Hz to 5000 kHz and outside the frequency spectrum of the acoustic noise of the main pipe. Generation and reception of acoustic signals produced by acoustic transmitters and receivers, respectively, installed on the outer surface of the main pipeline. After receiving the reflected echo pulses, the time τ of their delay relative to the probing signal is determined by correlation and threshold processing of the received echo signals.

To increase the accuracy of measurements, the delay value τ amplitude, frequency, or initial phase of the probing signals, if necessary, are modulated by noise-resistant codes. As a noise-resistant modulation codes use the Barker codes, M-sequence, Jacobi codes, non-linear or additional sequence of modulating pulses.

Further, on the basis of the found numerical value τ of the delay of the signals, determine the distance R from the measurement site to the in-line projectile from the above ratio R = V⋅τ / 2.

The invention is illustrated by drawings:

FIG. 1 is a drawing explaining the essence of the method for measuring the distance to the in-tube projectile; FIG. 2 - the design of the device implementing the method of pulse-acoustic determination of the location of the in-line cleaning projectile in the main pipeline and the scheme of its installation on the main pipeline. FIG. 1-2 are marked:

1 - the device of the pulse-acoustic determination of the location of the in-line cleaning projectile;

2 - in-tube cleaning projectile;

3 - main oil and gas pipeline (pipe);

4- transmitter of acoustic signals 8 with a digital input;

4.1 - digital-to-analog converter (DAC);

4.2 - power amplifier of electrical signals;

4.3 - piezoceramic electrostriction radiator of mechanical (acoustic) signals;

5 - receiver of acoustic signals with a digital output;

5.1 - piezoceramic electrostrictive converter 5.1 mechanical (acoustic) signals into an electrical signal;

5.2 - electric signal amplifier;

5.3 - analog-to-digital converter (ADC) of analog electric signals into a digital signal;

6 - digital device for generating and processing signals;

6.1 - bidirectional interface bus interface;

6.2 - the controlling controller;

6.3 - digital signal generator;

6.4 - digital correlator;

6.5 - random access memory (RAM);

6.6 - reprogrammable memory device (ROM);

6.7 - communication port;

7 - digital indicator;

8 - probe signal (U _probe );

9 - response echo (U _ref ).

According to FIG. 1-2 device 1 pulse-acoustic determination of the location of the in-line cleaning projectile 2 in the main pipeline 3, which implements the proposed method of measurement, includes an acoustic transmitter 4 with a digital input and a receiver 5 of acoustic signals with a digital output. The transmitter 4 and the receiver 5 of the acoustic signals are connected via a digital device 6 for generating and processing signals with a digital indicator 7. Moreover, the digital device 6 for generating and processing signals includes a bi-directional interface interface bus 6.1 on which a control controller 6.2 is installed, a generator 6.3 of digital signals; digital correlator 6.4; random access memory (RAM) 6.5; reprogrammable memory device (ROM) 6.6 and communication port 6.7. Acoustic transmitter 4 with a digital output contains a serially connected digital-to-analog converter (DAC) 4.1, an amplifier 4.2 of the power of electrical signals and a piezoceramic electrostrictive emitter 4.3 of mechanical acoustic vibrations. The receiver 5 of acoustic signals contains a series-connected piezoceramic electrostrictive converter 5.1 of mechanical oscillations into an electrical signal, an amplifier 5.2 of electrical signals and an analog-to-digital converter (ADC) 5.3 analog electrical signals into a digital signal.

The device 1 pulse-acoustic positioning of the in-line cleaning projectile 2 in the main pipeline 3 according to the proposed method works as follows.

Before starting the operation, the device 1 is placed directly on the external surface of the main pipeline 3 in which the detection of the in-line cleaning projectile 2 is necessary.

Next, they turn on the power supply of the device 1 (not shown in the figures) and the controlling controller 6.2 of the digital device 6, according to the program set in the EPROM 6.1, generates commands for controlling the generation of probe 8 and processing the response 9 signals. At the same time, the piezoceramic converter 5.1 of the receiver 5 receives the mechanical noise vibrations of the pipe caused by the working fluid passing through it (oil or gas) and converts them into an electrical noise signal U _noise . Next, the received analog noise signals U _{noise are} amplified by an amplifier 5.2 and converted to a digital signal in ADC 5.3 and transmitted to a digital correlator 6.4 of a digital device 6 for filtering and correlation processing of noise signals. In block 6.4, the noise spectrum U is determined by the signal _noise and the spectrum parameters are transmitted via line 6.1 under the control of controller 6.2 to generator 6.3 to generate a sounding signal (ES). Based on the analysis of the spectrum of the noise signal U _noise generator 6.3 generates a ES with amplitude U _probe in digital form and with an audio frequency in the frequency range from 300 Hz to 5000 kHz and outside the noise spectrum U the _{noise of the} main pipeline. This signal is sent to the transmitter 4. In the DAC 4.1, the transmitter of the 4 ES is converted to analog form. Further, in the amplifier 4.2, the ES is amplified in power and transmitted to the piezoceramic electrostrictive emitter 4.3. Emitter 4.3 based on the electrostriction effect of piezoelectric ceramics converts electric ES into mechanical oscillations of sound frequency. These vibrations excite in pipe 3 at the place of installation of the radiator 4.3 mechanical oscillations 8 of the working medium (oil, gas) sound frequency. Some of these oscillations (longitudinal sound waves) 8 in the working medium propagate in the pipe 3 towards the cleaning projectile 2 at a speed V, depending on the density of the working fluid (liquid or gas). Reaching through the cleaning time delay τ of the projectile 2 the sound wave is reflected from it, and a reflected echo U _Neg 8 returns in the opposite direction through the pipe 3, and received by the receiver 5. The received echoes U mechanical _Neg converted to 5.1 piezoceramic transducer receiver 5 into analog form, amplified amplifier 5.2, converted to ADC 5.3 in digital form and transmitted to the correlator 6.4. In the correlator 6.4, the probe U _probe and the reflected signal U _{ref are convolved} and their mutual correlation function is formed, the maximum value of U _to which determines the numerical value of the time delay τ between the signals U _probe and U _ref . To increase the measurement accuracy of magnitude x amplitude, frequency, and / or initial phase of the probing signals U, the _probe can be modulated by noise-resistant codes, such as Barker codes, M-sequences, Jacobi codes, nonlinear or additional sequences of modulating pulses. Further, on the basis of the found value of x delay between the signals U _probe and U _det, determine the distance R from the measurement point to the internal projectile from the condition R = V⋅τ / 2, where V is the speed of sound in the medium of the main pipeline.

The invention was developed at the level of a prototype that implements the proposed method for determining the location of the in-line projectile in the main pipeline. Tests of the prototype showed an increase in the productivity of measurements of the location of the in-line projectile in the main pipeline according to the proposed method by eliminating the need to open the pipe for the indicated measurements. At the same time, the accuracy of measuring the location of the position of the projectile in the main pipe increased due to the correlation processing of the received signals.

Claims (4)

1. Pulse-acoustic method of determining the location of the in-line cleaning projectile in the main pipeline, which consists in generating and sending pulsed acoustic probe signals from a predetermined measurement point on the main pipeline, receiving an acoustic echo impulse reflected from the in-tube, measuring the time interval τ from the moment of sending a probe pulse to receiving the time pulse-echo and determining the distance R from the measuring position to the pigging of conditions R = ^V, τ / 2, where V - with Soundness in the medium of the main pipeline, characterized in that before generating acoustic sounding signals, the spectrum of acoustic noise in the main pipe is additionally measured, the carrier frequency of the acoustic sounding signals is chosen outside the frequency spectrum of acoustic noise of the main pipe, acoustic signals are generated and received receivers, respectively, installed on the main pipeline, after receiving the reflected echo pulses, determine the time τ of them delays relative to the probing signal by correlation and threshold processing of received echo signals. 2. Pulse-acoustic method according to claim 1, characterized in that the amplitude, frequency or initial phase of the sounding signals are modulated by noise-resistant codes. 3. Pulse-acoustic method according to claim 2, characterized in that the Barker codes, M-sequences, Jacobi codes, non-linear or additional sequences of modulating pulses are used as the noise-resistant modulation codes. 4. Pulse-acoustic method according to claim 1, characterized in that the carrier frequency of the acoustic probing signals is chosen in the range of carrier frequencies from 300 Hz to 5000 kHz.

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