Method for monitoring an electrical power supply line comprised in a seismic cable, corresponding system, computer program product and non-transitory computer-readable carrier medium

Patent metadata

Field	Value
Publication number	US-9766281-B2
Application number	US-201514629035-A
Country	US
Kind code	B2
Filing date	Feb 23, 2015
Priority date	Feb 21, 2014
Publication date	Sep 19, 2017
Grant date	Sep 19, 2017

Abstract

It is proposed a method for monitoring an electrical power supply line comprised in a seismic cable and extending along the seismic cable. The seismic cable includes: a plurality of seismic sensors arranged along the seismic cable, a plurality of controllers arranged along the seismic cable, and an optical transmission line extending along the seismic cable for carrying data signals from or towards the controllers. The electrical power supply line supplies at least one pair of master and slave controllers. The master controller of a given pair of master and slave controllers performs a step of monitoring a portion of the electrical power supply line between the master and slave controllers, by using an optical loop established on a portion of the optical transmission line between the master and slave controllers, and starting from the master controller and passing through the slave controller.

First claim

The invention claimed is:

1. A method for monitoring an electrical power supply line comprised in a seismic cable and extending along said seismic cable, said seismic cable further comprising:
a plurality of seismic sensors arranged along the seismic cable,
a plurality of controllers arranged along the seismic cable,
an optical transmission line extending along said seismic cable for carrying data signals from or towards said controllers,
said electrical power supply line supplying at least one pair of master and slave controllers,
wherein the method comprises, for at least one given pair of master and slave controllers:
the master controller monitoring a portion of said electrical power supply line comprised between said master and slave controllers, by using an optical loop established on a portion of said optical transmission line comprised between said master and slave controllers.

2. The method according to claim 1 , wherein the master controller further performs:
emitting an optical test signal through the portion of said optical transmission line comprised between said master and slave controllers,
receiving an optical return signal supposed to result from a reflection of said test signal by the slave controller,
said monitoring the portion of said electrical power supply line being performed as a function of said return signal.

3. The method according to claim 2 , wherein the master controller further performs:
determining an effective propagation duration elapsed between an emission instant of said optical test signal and a reception instant of said optical return signal;
a first step of comparing the effective propagation duration with a first reference propagation duration which is as a function of a predetermined distance separating the master and slave controllers;
obtaining a first piece of monitoring information as a function of the result of said first step of comparing.

4. The method according to claim 3 , wherein said at least one given pair of master and slave controllers are separated by a cable portion comprising a plurality of cable sections, each cable section having an optical connector on both ends of said cable section,
and wherein the master controller further performs, if the effective propagation duration is different from the first reference propagation duration:
a second step of comparing the effective propagation duration with at least one second reference propagation duration, each being as a function of a predetermined distance separating said master controller and one of said optical connectors of the cable portion;
obtaining a second piece of monitoring information as a function of the result of said second step of comparing.

5. The method according to claim 3 , wherein the master controller further performs:
processing said first piece of monitoring information and/or said second piece of monitoring information,
delivering a positive or negative decision to stop supplying said slave controller via the portion of said electrical power supply line, as a function of the result of said step of processing.

6. The method according to claim 3 , wherein the master controller further performs sending said first second piece of monitoring information and/or said second piece of monitoring information to a remote control system, accompanied with an identifier of said master controller, so as to take a positive or negative decision to stop supplying on said electrical power supply line.

7. A system for monitoring an electrical power supply line included in a seismic cable and extending along said seismic cable, said seismic cable further including:
a plurality of seismic sensors arranged along the seismic cable,
a plurality of controllers arranged along the seismic cable,
an optical transmission line extending along said seismic cable for carrying data signals from or towards said controllers,
said electrical power supply line supplying in cascade a succession of pairs of master and slave controllers on a succession of portions of said electrical power supply line,
wherein the system comprises, for at least one given pair of master and slave controllers:

optical means arranged to cooperate with a portion of said optical transmission line comprised between said master and slave controllers so as to form an optical loop starting from the master controller and passing through the slave controller, and
means for monitoring, using said optical loop to monitor a portion of said electrical power supply line comprised between the master and slave controllers.

8. The system according to claim 7 , wherein said optical means comprise:
on the master controller side:
an optical source arranged for generating an optical test signal through the portion of said optical transmission line,
an optical sensor arranged for receiving an optical return signal supposed to result from a reflection of said optical test signal by light signal reflecting means comprised within the slave controller,

on the slave controller side:
said light signal reflecting means arranged for reflecting said optical test signal coming from the master controller.

9. The system according to claim 8 , wherein said means for monitoring comprise means for processing the optical return signal received by the optical sensor.

10. The system according to claim 8 , wherein said light signal reflecting means comprise a device having a return loss coefficient which is upper than −15 dB.

11. The system according to claim 10 , wherein said device belongs to the following group:
an optical reflective mirror;
a disconnected right-cleaved physical contact optical connector.

12. The system according to claim 7 , wherein said at least one given pair of master and slave controllers are separated by a cable portion comprising a plurality of cable sections, each cable section comprising an optical connector on both ends of said cable section having a return loss coefficient which is upper than −15 dB when disconnected.

13. The system according to claim 12 , wherein each optical connector is a right-cleaved physical contact optical connector.

14. The system according to claim 7 , wherein the seismic cable belongs to the group comprising:
a seismic streamer;
an ocean bottom cable.

15. A non-transitory computer-readable carrier medium storing a computer program product comprising a computer program code instructions which, when executed on a computer or a processor, implement a method for monitoring an electrical power supply line comprised in a seismic cable and extending along said seismic cable, said seismic cable further comprising:
a plurality of seismic sensors arranged along the seismic cable,
a plurality of controllers arranged along the seismic cable,
an optical transmission line extending along said seismic cable for carrying data signals from or towards said controllers,
said electrical power supply line supplying at least one pair of master and slave controllers,
wherein, for at least one given pair of master and slave controllers, the method comprises:
the master controller monitoring a portion of said electrical power supply line comprised between said master and slave controllers, by using an optical loop established on a portion of said optical transmission line comprised between said master and slave controllers.

Assignees

• Sercel Rech Const Elect

Inventors

• Sellin Isabelle

Classifications

• G01V1/201 Primary

  Constructional details of seismic cables, e.g. streamers (integrated optoseismic systems G01V1/226; line connectors in general H01R, transducer mountings in general G10K11/004) · CPC title

• G01R31/083

  in cables, e.g. underground · CPC title

• G01M11/083

  by using an optical fiber in contact with the device under test [DUT] · CPC title

• G01R31/58 Primary

  Testing of lines, cables or conductors (testing of electric windings G01R31/72) · CPC title

• G01V1/38

  specially adapted for water-covered areas (G01V1/28 takes precedence) · CPC title