Downhole signal coupling system

Abstract

A signal coupling system for data and / or power signalling in tubing within a hydrocarbon extraction well. First and second transceivers are arranged with primary and secondary loops lying orthogonal to the ends of the transceivers. The transceivers can be narrower for access downhole. Each loop is housed in a semi-cylindrical housing with a planar face, so providing a cylindrical body when oppositely arranged for the transfer of electromagnetic radiation therebetween. Guiding surfaces are also provided on the housing to assist in bring the coupling system together downhole. The present invention provides reliable real-time data from any location within the wellbore and improves reservoir management, well planning and resource exploitation.

Description

CROSS-REFERENCE TO RELATED APPLICATIONS[0001]This application claims the benefit of GB 1010095.6 filed Jun. 16, 2010, which application is fully incorporated herein by reference.FIELD OF THE INVENTION[0002]The present invention relates to a signal coupling system for the transfer of data signals and / or power signals downhole in a wellbore. More particularly, the present invention relates to a signal coupling system having a primary loop and a secondary loop in a vertical orientation to provide electromagnetic coupling in tubing in a hydrocarbon extraction well.BACKGROUND OF THE INVENTION[0003]The extraction of hydrocarbons from a well system is a very challenging task with such systems typically comprising a complex network of metallic pipes through which oil or gas is supplied from an underground reservoir to a production platform. In the most complex installations the reservoir may be located within the ground beneath the sea where a production pipe system is utilized to carry ext...

AI Technical Summary

Benefits of technology

[0010]It is a further object of at least one embodiment of the present invention to provide a signal coupling system for use in a hydrocarbon extraction well that recognizes the constraints of the tubing arrangement and thus maximizes the communication area between first and second transceiver.

[0033]Preferably, the method includes the step of tranferring power down said first cable between said transceivers and to said sensor. In this way, power can be transmitted to a gauge downhole, so that a permanent power cable is not required.

Problems solved by technology

The extraction of hydrocarbons from a well system is a very challenging task with such systems typically comprising a complex network of metallic pipes through which oil or gas is supplied from an underground reservoir to a production platform.

The requirement to provide such information is extremely challenging due to the very constrained nature of the pipe or tubing structure.

Acoustic signaling within the pipe walls and through the fluid carried by production pipes suffers from similar limitations.

However, these systems do suffer from interference from the acoustic noise generated by drilling operations.

This technique has also been found to be unreliable in an extreme environment such as in a well system.

Furthermore, the production tubing and casing are assembled in sections and this complicates deployment of a wired system.

In this environment electrically conductive cables and electrically conductive connectors provide very low reliability.

Moreover, hard wired cables are permanently interfaced to control devices and sensors and should one part of the system fail then this often results in failure of the whole command and control network.

Such single point failure is highly undesirable in a wellbore system as the remedial work prevents production and is costly.

In summary, the communication systems described above are disadvantageous in that they are complicated to use, unreliable due to the harsh environment in which they are exposed, expensive to install and even more expensive to repair.

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