| 摘要 |
<p>KELLY DRIVE BUSHING ADAPTER An adapter is provided for positioning a kelly drive bushing of a surface drilling assembly in spaced relationship to an associated rotary table. The adapter permits the wireline of an electronic steering assembly to pass through the central aperture in the rotary table below the drive bushing to surface readout equipment, enabling the electronic steering assembly to be employed for drilling directional bores without removal of the kelly.</p> |
