RU2841659C1 - Method of locating pipeline pigs in main and field oil pipelines - Google Patents

Abstract

FIELD: pipeline transport.

SUBSTANCE: method of locating pipeline pigs in main and field oil pipelines consists in using pipeline filled with oil as acoustic communication channel for signal transmission. Acoustic transmitter initiates single pulses through certain intervals of the distance travelled on the odometer, which, having passed through the pumped medium of the oil pipeline, reach the acoustic receiver and are detected by it. Program of the acoustic receiver determines the value of the distance travelled by the pig based on the number of received pulses and the fixed value of the distance interval, at which said pulses are initiated. Intervals of distances, at which single acoustic impulses are initiated, are selected on the basis of time required for complete attenuation of impulses sent earlier. When pipeline pig stops, data packet is transmitted by coded signals that contains values of the distance passed by the pig from the place of the last sending of single impulse to the place of its stop. Accuracy of locating pipeline pigs using the disclosed method corresponds to accuracy of measuring the distance travelled by a pig with an odometer, which considerably exceeds accuracy of systems based on the echo-ranging principle of operation. Advantage of this method is also the possibility of installing the acoustic receiver at any accessible point of the linear part of the pipe in the direction of propagation of the acoustic pulse.

EFFECT: high accuracy and reliability of locating pipeline pigs in main and field oil pipelines in remote mode, including in cases of shutdown thereof.

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Description

The invention relates to the field of pipeline transportation of oil and oil products and can be used to determine the location of in-pipe tools used for diagnostics and cleaning of the internal cavity of main and field oil pipelines.

A device is known for determining the location of cleaning and diagnostic tools in a pipeline (RU Patent No. 2110729, IPC F17D 5/00 (1995.01), published 10.05.1998), the essence of which lies in determining the location of cleaning and diagnostic tools in a pipeline using a transmitter mounted on the tool and a receiver with an antenna for receiving signals from the transmitter located above the pipeline. The transmitter emits electromagnetic signals in the frequency range of 7 - 11 Hz and with a duty cycle that is set depending on the speed of the tool.

The disadvantage of this device is the small radius of detection of the in-pipe projectile, which does not allow for constant monitoring of its location.

A known method for pulse-acoustic determination of the location of an in-pipe cleaning tool in a main pipeline (RU Patent No. 2691779, MGTK G01S 15/08 (2006.01), F16L 55/48 (2006.01), published on 18.06.2019) consists in generating and sending pulse acoustic probing signals from a given measurement point on the main pipeline, receiving an acoustic echo pulse reflected from the in-pipe tool, measuring the time interval τ from the moment the probing pulse is sent to the moment the echo pulse is received, and determining the distance R from the measurement point to the in-pipe tool from the condition R = V * τ / 2, where V is the speed of sound in the medium of the main pipeline, while before generating acoustic probing signals, the spectrum of acoustic noise in the main pipeline, the carrier frequency of the acoustic The probing signals are selected outside the frequency spectrum of the acoustic noise of the main pipeline, the generation and reception of acoustic signals are carried out using acoustic transmitters and receivers, respectively, installed on the main pipeline, after receiving the reflected echo pulses, the time t of their delay relative to the probing signal is determined by correlation and threshold processing of the received echo signals.

The disadvantage of this method is the high error in determining the location of in-pipe shells, due to the lack of measurement of the actual speed of sound in the pumped medium. Another disadvantage of this method is the use of a bidirectional acoustic pulse transmission scheme, leading to additional accumulation of distance measurement error due to inaccurate determination of the speed of sound propagation in the pumped medium.

A method of acoustic ranging is known (patent of the Russian Federation No. 2392641 MGTK (2006.01) G01S 15/08, published on 20.06.2010), according to which the transmission of a probing signal and the reception of a response signal are carried out sequentially from two points spaced apart from each other on the outside of the pipe with a known distance between them. The speed of propagation of ultrasound in the medium filling the pipeline is determined by dividing the doubled distance between the first and second points by the difference in the bidirectional propagation time of signals between the in-pipe object and the first and second points, using the obtained speed value, the distances to the in-pipe object are determined.

The disadvantage of this method is the presence of an error in determining the location of in-pipe projectiles, caused by insufficient accuracy in determining the speed of sound in the pumped medium. According to this method, the measurement of the speed of ultrasound propagation in the medium is carried out on a limited section, in which the measured speed can differ significantly from the speed on a longer section between the sensor and the in-pipe projectile. The difference in the speed of sound propagation on a limited section from the extended section between the in-pipe projectile and the sensor is due to the uneven distribution of the speed of sound in the pumped medium along the linear part of the oil pipeline, which is a consequence of the uneven distribution of temperature. Another disadvantage of this method is the use of a bidirectional acoustic pulse transmission scheme, leading to additional accumulation of distance measurement error due to inaccurate determination of the speed of sound propagation in the pumped medium.

The prototype chosen is the method implemented by the in-line device tracking system (RU Patent No. 38499 IPC (2000.01) F17D 5/02, published on 20.06.2004), consisting of a transmitter mounted on the projectile, containing a sealed container with an autonomous power source, and a receiver located outside the pipeline and containing a decoder, the input of which is connected to the output of the primary signal converter module. During the projectile movement in the pipeline, the acoustic emitter emits packets of sound signals with a certain periodicity. The sound signals sent by the emitter in the pipeline filled with oil are transmitted as in a waveguide and received by the acoustic sensor of the primary signal conversion module. The primary conversion module is mounted on the air valve through a standard flange connection. From the primary signal conversion module, the primarily processed acoustic signal enters the signal processing and transmission module, where digital processing of the received signal occurs, the selection of the acoustic image sent by the emitter, accumulation of information on the progress of tracking, calculation of the speed and location of the projectile, preparation and organization of the transmission of information via telemetry and communication channels.

The disadvantage of this system is the low accuracy of determining the location of the in-pipe tool due to the presence of an error caused by insufficient accuracy in determining the speed of sound, which depends on the properties of the pumped medium. This disadvantage is common to methods based on calculating the distance by the time of passage of acoustic pulses. High error in determining the location of in-pipe tools leads to the impossibility of promptly determining the location and further extraction of in-pipe tools when they stop.

The technical problem of the invention is the creation of a method for determining the location of in-pipe devices in main and field pipelines with the achievement of the following technical result: increasing the accuracy and reliability of determining the location of in-pipe devices in a remote mode, including in cases of shutdown, ensuring the possibility of prompt extraction of in-pipe devices.

The specified technical result is achieved by the fact that in the method for determining the location of in-pipe projectiles in main and field oil pipelines, which consists in transmitting, by an acoustic emitter installed on the in-pipe projectile, packets of sound signals with a certain periodicity, which, propagating in the pipeline as in a waveguide, are received by the module of the primary signal converter and transmitted to the module for processing and transmitting the signal, in which the speed and location of the in-pipe projectile are calculated, according to the invention, the acoustic transmitter installed on the in-pipe projectile transmits coded acoustic signals of data containing the values of the distance traveled by the projectile, measured by an odometer installed on the projectile. The acoustic transmitter initiates single pulses at certain intervals of the distance traveled according to the odometer, which, having passed through the pumped medium of the oil pipeline, reach the acoustic receiver and are recorded by it, while the calculation of the value of the distance traveled by the projectile is carried out based on the number of received pulses and the fixed value of the distance interval at which these pulses are initiated. When the in-pipe projectile stops, the acoustic transmitter transmits coded signals of a data packet containing the values of the distance traveled by the projectile from the place of the last sending of a single pulse to the place of the in-pipe projectile stop; these data packets are received by the receiver and output as the current value of the distance traveled by the in-pipe projectile from the place of its launch to the place of its stop.

The prior art discloses methods for remotely determining the location of in-pipe tools based on the possibility of transmitting acoustic signals through the pumped medium of a pipeline using echolocation principles. Methods for transmitting data using coded acoustic signals are known. It is known to use odometers to determine the distance traveled by in-pipe tools with high accuracy, but there is no possibility of remotely determining the location of the tool. The two-mode method for sending acoustic signals during the movement and stop of the in-pipe tool described in the invention allows to reduce the size of the transmitted data packets to a minimum size, which in turn increases the reliability of the method as a whole. The combined use of these methods allows to obtain a new technical result: the possibility of reliably remotely determining the location of in-pipe tools with an accuracy corresponding to the accuracy of odometers.

When the in-line tool is moving, the distance traveled is measured by the odometer. The acoustic transmitter initiates single pulses at certain intervals of the distance traveled to the odometer, which, having passed through the pumped medium of the oil pipeline, reach the acoustic receiver and are recorded by it. The program of the acoustic receiver determines the value of the distance traveled by the tool based on the number of pulses received and the fixed value of the distance interval at which these pulses are initiated. The distance intervals at which single acoustic pulses are initiated must be selected based on the time required for the complete attenuation of the pulses sent earlier. When the in-line tool stops, the acoustic transmitter transmits a data packet in coded signals containing the values of the distance traveled by the tool from the place of the last single pulse sent to the place of its stop. Data packets transmitted by coded signals are received by the receiver and output as the current value of the distance traveled by the in-pipe tool from the launch site to the stop site. The accuracy of determining the location of in-pipe tools by the proposed method corresponds to the accuracy of measuring the distance traveled by the tool by an odometer, significantly exceeding the accuracy of systems based on the echolocation principle of operation. Another advantage of this method is the ability to install an acoustic receiver in any accessible place of the linear section of the pipeline in the direction of propagation of the acoustic pulse.

Fig. 1 shows a diagram of the arrangement of components of the proposed method for determining the location of in-pipe tools, Fig. 2 shows a laboratory stand, and Fig. 3 shows an oscillogram of the communication protocol of the laboratory stand.

The method for determining the location of in-pipe tools involves the use of an odometer 1, an acoustic transmitter 2, a control and power supply unit 3, installed on the in-pipe tool 4. The acoustic receiver consists of a hydrophone 5 and a secondary converter 6. The secondary converter 6 processes the received information, outputs and stores data.

The method was tested on a laboratory bench (Fig. 2). The laboratory bench consists of a pipe 7 2 meters long, which includes various shaped parts (tees and bends) allowing to change the route of its installation, a model of an in-pipe tool 4, consisting of an acoustic transmitter 2, a control and power supply unit 3, and an acoustic receiver consisting of an ultrasonic hydrophone 5 and a secondary converter 6. Transmission of coded acoustic pulses was carried out by the acoustic transmitter 2, reception was carried out by the acoustic receiver. Sending data was carried out by acoustic signals formed by pulse modulation of the carrier acoustic wave of the ultrasonic frequency range according to the 8-bit communication protocol (Fig. 3). The control unit is assembled on the basis of the Arduino Nano platform, built on the ATmega328 microcontroller. The microcontroller provided the input of the transmitted data, their encoding and output of information. The input of the transmitted data was carried out by setting the position of the control unit potentiometer in the range of values from 0 to 255. The information was output to the LCD display. The acoustic signal was transmitted by an acoustic transmitter assembled on the basis of an integrated circuit of the NE555 precision timer and a 2N2222 transistor. An ultrasonic piezoelectric speaker was used as an acoustic pulse emitter. The secondary converter of the receiver is assembled on the basis of the Arduino Nano platform, built on the ATmega328 microcontroller. The microcontroller processes the received signals and outputs information. The receiver hydrophone is made on the basis of a piezoelectric microphone, an integrated circuit of the LM741 operational amplifier and an LM567 tone decoder microcircuit.

The studies conducted on the laboratory stand demonstrated the possibility of reliable transmission of data packets by coded acoustic signals regardless of the pipe laying route and the presence of shaped parts in it.

Numerical modeling was also performed using specialized programs for the process of transmitting data packets by coded acoustic signals in a 10 km long oil pipeline with the main elements of the main oil pipeline (branches, transitions, loops). Numerical modeling also demonstrated the possibility of transmitting data packets by coded acoustic signals over distances of tens of kilometers in an oil pipeline without data loss or distortion.

The proposed technical solution allows for more accurate determination of the location of in-pipe shells remotely, including in cases of shutdown, which enables the prompt extraction of in-pipe shells.

Claims (2)

1. A method for determining the location of in-line drills in main and field oil pipelines, consisting of transmitting packets of sound signals with a certain periodicity by an acoustic emitter installed on the in-line drill, which, propagating in the pipeline as in a waveguide, are received by a module of the primary signal converter and transmitted to a module for processing and transmitting a signal, in which the speed and location of the in-line drill are calculated, characterized in that the acoustic transmitter installed on the in-line drill transmits data by coded acoustic signals containing the values of the distance traveled by the drill, measured by an odometer installed on the drill. 2. A method for determining the location of in-pipe projectiles according to paragraph 1, characterized in that when the in-pipe projectile stops, the acoustic transmitter transmits coded signals of a data packet containing the values of the distance traveled by the projectile from the place of the last sending of a single pulse to the place of its stop; these data packets are received by the receiver and output as the current value of the distance traveled by the in-pipe projectile from the place of launch to the place of its stop.