Patent ID: 6531871
Filing Date: 2003-03-11
Classification: E21B,H01Q,H04B

Abstract:
An electromagnetic antenna extension assembly for connection into a pipe string between a downhole data transmission unit for generating an electromagnetic signal and a downhole electromagnetic antenna for transmitting the electromagnetic signal, wherein the downhole electromagnetic antenna is of a type comprising a conductive outer antenna member and a conductive inner antenna member therein having a lower electrical connector and wherein the downhole data transmission unit is of a type comprising a conductive outer transmission member and an inner data transmission tool therein having an upper electrical connector connectable with the lower connector of the inner antenna member, the electromagnetic antenna extension assembly comprising at least one extension tool comprised of:(a) an electrically conductive outer extension member having an upper end connectable with the outer antenna member and a lower end connectable with the outer transmission member; and (b) an electrically conductive inner extension member mounted and extending within the outer extension member and having an upper end connectable with the lower connector of the inner antenna member and a lower end connectable with the upper connector of the inner data transmission tool; such that the electromagnetic signal is communicable between the downhole data transmission unit and the downhole electromagnetic antenna.