| 摘要 |
<p>A transmitter accommodated within the drill collar of a drill pipe transmits information from sensors at the bottom of a drilling well using an antenna of a special type which, unlike prior antenna, does not cause weakening of the drill collar and which allows signal transmission even when -the drill collar is immersed in insulating mud. The antenna consists of a cylindrical metal sleeve which is shorter than but has a greater diameter than the drill collar. The antenna is arranged coaxially on the drill collar, being separated from it by an insulating sheathing covering the drill collar.</p> |
