| 摘要 |
<p>A system for performing wellbore telemetry operations wherein a communication link between a subsurface location in a well and the location substantially at the surface is established and maintained through electromagnetic coupling between two insulated electric conductors. The first conductor is electrically coupled to a transmitter, normally located at the subsurface location, and extends upwardly in the well. The second conductor is electrically coupled to a receiver, normally at the surface location, and extends down into the well. Normally, the two conductors will overlap along a substantial portion of the lengths thereof. As the well is drilled deeper and the drill string is lengthened, the transmitter and the first conductor follow the progression of the wellbore into the earth, thereby reducing the overlap between the first and second conductors. When the two conductors cease to overlap, the second conductor may be lengthened to re-establish the overlap.</p> |
