Bit-stabilized combination coring and drilling system
AssigneeBaker Hughes Incorporated
InventorsBarry W. Struthers, Pierre E. Collee
Life of this patent
Estimating the term…
Abstract
A core barrel having an inner tube for coring and, alternately, a center plug assembly or closing the throat of the core bit at the bottom of the assembly for drilling in lieu of coring. The inner tube assembly and plug assembly are disposable and retrievable through the drill string on a wireline using an overshot. The core bit is of a stabilized, preferably anti-whirl, design and may be a low-invasion core bit used in cooperation with a low-invasion coring shoe. A logging tool and data transmission assembly may be incorporated in the plug assembly for logging while drilling.
Claims20
An apparatus for alternately coring and drilling of a subterranean formation without tripping of a drill string to which said apparatus is secured, comprising:
- an outer barrel assembly including a tubular outer barrel having means at the top thereof for securing the apparatus to the end of a drill string, a latch coupling on the upper interior thereof, and a PDC core bit having a throat and secured to the lower end thereof;
- an inner tube assembly configured for placement on the interior of said outer barrel assembly, including coupling means at the top thereof for releasable engagement of a wireline retrieval assembly, a latch assembly for releasable engagement of said latch coupling, a rotational bearing assembly below said latch assembly for permitting mutual rotation between the segments of the inner tube assembly above and below the latch assembly, and an inner tube for receiving a core cut by said core bit;
- and
- a center plug assembly configured for placement on the interior of said outer barrel assembly, including coupling means at the top thereof for releasable engagement of a wireline retrieval assembly, a latch assembly for releasable engagement of said latch coupling, a center bit plug at the lowermost end thereof for disposition in said core bit throat, said bit plug having a plug face including PDC cutters disposed thereon and internal passages for receiving drilling fluid from the interior of said outer barrel and directing said drilling fluid to said plug face;
- said inner tube assembly and said center plug assembly being interchangeable in said outer barrel assembly to permit, respectively, alternate coring and drilling of said subterranean formation.
An apparatus for alternate coring and drilling of a subterranean formation without tripping of a drill string to which said apparatus is secured, comprising:
- an outer barrel assembly including a tubular outer barrel having means at the top thereof for securing the apparatus to the end of a drill string, a latch coupling on the upper interior thereof, a bit end rotational bearing assembly on the lower interior thereof, and a stabilized PDC core bit having a throat and secured to the lower end thereof;
- an inner tube assembly configured for placement on the interior of said outer barrel assembly, including coupling means at the top thereof for releasable engagement of a wireline retrieval assembly, a latch assembly for releasable engagement of said latch coupling, a rotational bearing assembly below said latch assembly for permitting mutual rotation between the segments of the inner tube assembly above and below the latch assembly, and an inner tube for receiving a core cut by said core bit, the lower end of said inner tube being adapted to engage said bit end rotational bearing assembly;
- and
- a center plug assembly configured for placement on the interior of said outer barrel assembly, including coupling means at the top thereof for releasable engagement of a wireline retrieval assembly, a latch assembly for releasable engagement of said latch coupling, a center bit plug at the lowermost end thereof having a plug face including PDC cutters disposed thereon, and internal passages for receiving drilling fluid from the interior of said outer barrel and directing said drilling fluid to said plug face, the exterior of said center bit plug being sized to engage said bit end rotational bearing assembly and configured so that said plug face protrudes therebelow into said throat of said core bit to define, with said core bit, a PDC drill bit;
- said inner tube assembly and said center plug assembly being interchangeable in said outer barrel assembly to permit, respectively, alternate coring and drilling of said subterranean formation.
Dependencies are inferred from the claim text.