Patent ID: 7168510
Filing Date: 2007-01-30
Classification: E21B

Abstract:
1. A drill string communication apparatus to transmit electromagnetic energy, comprising: a first tubular member providing a longitudinal axial bore there through, said first tubular member having a first end containing a first toroidal inductor and a second end containing a second toroidal inductor, and providing a conductor from said first inductor to said second inductor; a second tubular member having a first end extending into the longitudinal axial bore of said first tubular member and rotatably supported therein; said second tubular member further providing an enlarged second end providing a connection to a drill string member, said enlarged second end having a shoulder adjacent the second end of the first tubular member providing a third toroidal inductor therein and a second end having a fourth toroidal inductor contained therein, and a conductor connecting the third inductor to the fourth inductor; said first tubular member and said second tubular member forming an axial gap between the second end of the first tubular member and the shoulder of said second tubular member; and wherein an electromagnetic signal can be inductively transmitted from the first end of the first tubular member to the second end of the second tubular member.