Method and system for the continuous remote tracking of a pig device and detection of anomalies inside a pressurized pipeline

Patent metadata

Field	Value
Publication number	US-10132823-B2
Application number	US-201514711885-A
Country	US
Kind code	B2
Filing date	May 14, 2015
Priority date	May 14, 2014
Publication date	Nov 20, 2018
Grant date	Nov 20, 2018

Abstract

A method and system are described for the continuous remote monitoring of the position and advance speed of a pig device inside a pipeline suitable for transporting a pressurized fluid, wherein the pipeline consists of a plurality of pipe sections joined to each other by welding. The method comprising the following steps: continuous acquisition and registration, by a plurality of measurement stations equipped with vibroacoustic sensors discretely located along the pipeline, of vibroacoustic signals due to hydraulic pressure transients, and/or to the vibrations generated by the pig device in movement in the contact/friction phases on the welding seams, and/or to other physical variations of the pipeline; analysis and processing, by a centralized control unit, of the vibroacoustic signals registered by the measurement stations to reveal, identify and reference the hydraulic/acoustic transients produced by the pig device during contact/friction with the weldings and/or with other variations in the internal section of the pipeline; continuous calculation of the linear position and advance speed of the pig device in relation to the time lapse between the vibroacoustic signals registered by at least two measurement stations installed along the pipeline.

First claim

The invention claimed is:

1. A method for the continuous remote monitoring of a position and advance speed of a pig device inside a pipeline suitable for transporting a pressurized fluid, wherein the pipeline includes a plurality of pipe sections joined to each other by welding seams, the method comprising the following:
continuously acquiring and recording, by a plurality of measurement stations equipped with vibroacoustic sensors discretely located along the pipeline, of vibroacoustic signals due to the vibrations generated by contact/friction of the pig device with the welding seams of the pipeline and/or with other physical variations locally present in multiple pipe sections of the pipeline;
analyzing and processing, by processing circuitry, the vibroacoustic signals registered by the measurement stations to reveal, identify and reference hydraulic/acoustic transients produced by the pig device as a result of contact/friction with the welding seams and/or with other variations of an internal section of the pipeline; and
continuously determining the linear position and advance speed of the pig device in relation to a time lapse between the vibroacoustic signals registered by at least two measurement stations installed along the pipeline,
wherein the determining of the linear position and advance speed of the pig device is performed by a first measurement station situated on a first side of the pipeline with respect to the position of the moving pig device and a second measurement station situated on the opposite side of the pipeline with respect to the position of said moving pig device, and
wherein the linear position and advance speed of the pig device are determined by analysis of cross-correlation on sliding time windows between the vibroacoustic signals registered by said two measurement stations installed along the pipeline, wherein a time instant of maximum correlation between the vibroacoustic signals is equal to a difference in the arrival times at said two measurement stations of the hydraulic/acoustic transients generated by the pig device and wherein the time is converted to distance by using known information on sound propagation speed in the fluid transported by the pipeline.

2. The method according to claim 1 , wherein the vibroacoustic signals emitted inside the pipeline and registered by the measurement stations are temporally synchronized through an absolute time reference system.

3. The method according to claim 1 , further comprising:
acquiring data relating to the linear position of the welding seams between the pipe sections forming the pipeline and data relating to possible variations and/or anomalies on the internal section of the pipeline.

4. The method according to claim 1 , wherein the identification of pressure peaks generated by the pig device while passing through the welding seams between the pipe sections forming the pipeline and the data relating to possible variations and/or anomalies of the internal section of the pipeline are obtained by calculating the Short Term Average over Long Term Average (STA-LTA) of the vibroacoustic signal recorded by a single measurement station and a definition of a threshold value on the resulting signal.

5. The method according to claim 4 , wherein the calculation of the STA-LTA of the vibroacoustic signal is performed through the following equation:

STA
-

LTA
⁡

(
n
)

=

[

∑

i
=
n

n
+
m

⁢

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

x
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(
i
)

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m

[

∑

i
=
k

n
+
k

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x
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(
i
)

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]

k

wherein x(n) is the n-th sample of the vibroacoustic signal registered by a single measurement station and sampled at the time instant nT, with T equal to the sampling period, and n, m, k are parameters consisting of integers which define the duration of the time window and m<k.

6. The method according to claim 5 , wherein the calculation of the normalized cross-correlation x c (n) on a sliding time window is performed through the following equation:

x
c

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(
n
)

=

∑

i
=
k

k
+
m

⁢

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x
2

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(
i
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x
3

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+
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)

Assignees

• Eni Spa

Inventors

• Giunta Giuseppe
• Bernasconi Giancarlo
• Del Giudice Silvio

Classifications

• G01M3/005

  using pigs or moles (G01M3/246, G01M3/2823 take precedence) · CPC title

• G01P3/64 Primary

  Devices characterised by the determination of the time taken to traverse a fixed distance · CPC title

• G01S5/22

  Position of source determined by co-ordinating a plurality of position lines defined by path-difference measurements (G01S5/28 takes precedence) · CPC title

• F16L55/48

  Indicating the position of the pig or mole in the pipe or conduit · CPC title

• G01V1/001 Primary

  Acoustic presence detection · CPC title