| 摘要 |
<p>There is provided a new and useful coring assembly (20) for mounting on the end of a drill string (18) and comprising a core barrel (26); abrading means (36) on at least a part of the core barrel; a reaming collar (30) mounted about a lower section of the core barrel and selectable between a first condition in which the collar is rotatable with the barrel and a second condition in which the collar is rotatable relative to and slidable longitudinally relative to the core barrel; a housing (60) suspended from the core barrel; a deflection crank (34) extending between the housing and the core barrel; and means (62, 64) within the housing for transferring power from a power source to the crank for selectively rotating the crank for moving the core barrel between a first position which the core barrel and the housing are aligned and a second position in which the barrel and the housing are not aligned.</p> |
