Transmission system for communication between downhole elements

摘要

The invention relates to a transmission system for transmitting signals between an inner and an outer unit separated by an annular pipe section wall, wherein said inner unit is provided with a first antenna and the second unit is provided with a second antenna, the antennas preferably constituted by coils, being adapted to be brought into essentially the same positions along the pipe section, wherein said pipe section is made from a material having low magnetic permeability and wherein at least one of the antennas is provided magnetic shield having high magnetic permeability, the corresponding antenna being positioned between the pipe wall and the magnetic shield and the magnetic shield extending along the length of the antenna.

主权项

1. A transmission system for transmitting signals, the transmission system comprising:
an inner unit comprising a first antenna, the inner unit being essentially concentric around a pipe for carrying fluids; an outer unit comprising a second antenna, the outer unit being separated from the inner unit in a radial direction by an annular pipe section that provides a pressure barrier between an inside and an outside of said annular pipe section and an annular gap that contains a fluid; wherein the first antenna and the second antenna are brought into essentially the same axial positions along said annular pipe section; wherein said annular pipe section is made from a material having low magnetic permeability; and wherein at least one antenna of the first antenna and the second antenna is provided with a magnetic shield having high magnetic permeability, the at least one antenna being positioned between the annular pipe section and the magnetic shield and the magnetic shield extending along an axial length of the at least one antenna.