Patent ID: 9670771
Date: 2017-06-06
CPC Classifications: E21B

Claim:
1. Apparatus for use in Electromagnetic (EM) telemetry, the apparatus comprising a gap sub comprising: first and second electrically conductive members the first and second electrically conductive members mechanically connected to one another and electrically insulated from one another; a pin coupling on the first electrically conductive member; a box coupling on the second electrically conductive member; a bore extending longitudinally through the gap sub from the pin coupling to the box coupling; and, an electromagnetic telemetry signal generator connected to apply an electrical signal between the first and second electrically conductive members; wherein the electromagnetic telemetry signal generator comprises a control circuit, and a power source wherein: the power source is configured to provide a first voltage to the control circuit; the control circuit is configured to drive a second voltage greater than the first voltage between the first and second electrically conductive members.