Abstract:
An apparatus for engaging a subterranean borehole includes a bi-center bit having backup cutting elements thereon. The bi-center bit includes a pilot bit section and a reamer bit section adjacent to the pilot bit section. The pilot bit section includes at least one primary cutting element and at least one backup cutting element rotationally trailing and laterally offset from the at least one primary cutting element. Methods of drilling a subterranean borehole include engaging a first portion of a borehole with a reamer bit section of a drill bit and simultaneously engaging a second, opposing portion of the borehole with a pilot bit section adjacent to the reamer bit section.
Abstract:
Earth-boring drill bits include a bit body including a blockage-resistant internal fluid passageway. The blockage-resistant internal fluid passageway includes at least one internal fluid passageway formed in the bit body and a cuttings filtering feature formed in the at least one internal fluid passageway configured to prevent at least some cuttings from flowing through the at least one internal fluid passageway. In one embodiment, the cuttings filtering feature includes at least one lateral member extending transversely across the at least one internal fluid passageway. In another embodiment, the cuttings filtering feature includes forming a central portion of the at least one internal fluid passageway with a width along a lateral axis thereof less than an average width of a fluid path extending through a nozzle disposed at least partially within the at least one internal fluid passageway. Methods of forming the blockage-resistant internal fluid passageway are also disclosed.
Abstract:
An apparatus for engaging a subterranean borehole includes a bi-center bit having backup cutting elements thereon. The bi-center bit includes a pilot bit section and a reamer bit section adjacent to the pilot bit section. The pilot bit section includes at least one primary cutting element and at least one backup cutting element rotationally trailing and laterally offset from the at least one primary cutting element. Methods of drilling a subterranean borehole include engaging a first portion of a borehole with a reamer bit section of a drill bit and simultaneously engaging a second, opposing portion of the borehole with a pilot bit section adjacent to the reamer bit section.
Abstract:
An expandable apparatus for use in a borehole includes a tubular body having at least one opening extending between a longitudinal bore of the tubular body and an outer surface of the tubular body and at least one member positioned within the at least one opening of the tubular body. The member is configured to move between a retracted position and an extended position. An actuation structure is positioned within the tubular body. The actuation structure is coupled to the at least one member and is configured to move the at least one member from the retracted position to the extended position responsive to a flow rate of drilling fluid passing through the longitudinal bore.
Abstract:
An expandable apparatus for use in a borehole includes a tubular body having at least one opening extending between a longitudinal bore of the tubular body and an outer surface of the tubular body and at least one member positioned within the at least one opening of the tubular body. The member is configured to move between a retracted position and an extended position. An actuation structure is positioned within the tubular body. The actuation structure is coupled to the at least one member and is configured to move the at least one member from the retracted position to the extended position responsive to a flow rate of drilling fluid passing through the longitudinal bore.
Abstract:
A rotary drill bit for drilling subterranean formations configured with at least one protective structure proximate to the rotationally leading and trailing edges of a gage trimmer, wherein the at least one protective structure is positioned at substantially the same exposure as its associated gage trimmer. Particularly, the apparatus of the present invention may provide protection for gage trimmers during drilling, tripping, and/or rotation within a casing; i.e., when changing a drilling fluid. Protective structures may be configured and located according to anticipated drilling conditions including helix angles. In addition, a protective structure may be proximate to more than one gage trimmer while having a substantially equal exposure to each associated gage trimmer. Methods of use and a method of rotary bit design are also disclosed.
Abstract:
Expandable reamer for drilling a subterranean formation comprises blades carried by a tubular body and each carrying cutting structure(s), a blade biasing element to hold a laterally movable blade at an innermost lateral position corresponding to an initial diameter of the reamer, a structure for retaining the movable blade at an outermost lateral position corresponding to an expanded diameter of the reamer, and an actuation device. Expandable reamer for drilling a subterranean formation comprises a tubular body (532) having a longitudinal axis (525) and a leading end for connecting to a pilot drill bit and a trailing end for connecting to a drill string, a drilling fluid flow path extending through the expandable reamer for conducting drilling fluid through it, radially and longitudinally extending blades (512, 514) carried by the tubular body and each carrying at least one cutting structure (536), a blade biasing element for holding a laterally movable blade at an innermost lateral position corresponding to no more than an initial diameter of the reamer with a force, a structure (516, 520) for retaining the laterally movable blade at an outermost lateral position corresponding to an expanded diameter of the reamer, and an actuation device positioned along an inner diameter of the tubular body and configured to selectively prevent or allow drilling fluid communication with the laterally movable blade according to a flow rate of drilling fluid passing through it. An independent claim is also included for a method of reaming a borehole in a subterranean formation, which comprises disposing an expandable reamer apparatus within the subterranean formation, biasing the laterally movable blade to a laterally innermost position corresponding to an initial diameter of the reamer, flowing drilling fluid through the reamer via a drilling fluid flow path while preventing drilling fluid from communicating with the movable blade, allowing drilling fluid to communicate with the movable blade, causing the movable blade to move to an outermost lateral position, and reaming a borehole in a subterranean formation by rotation and displacement of the reamer within the subterranean formation.
Abstract:
A rotary drilling bit has gage trimmers 92, each of which has a protective structure 90, 94 adjacent the leading and trailing edges thereof. The protective structures have the same exposure as its associated gage trimmer. The arrangement may provide protection for gage trimmers during drilling tripping and /or rotation within a casing ie when changing a drilling fluid. Protective structures may be configured and located according to anticipated drilling conditions including helix angles. Details of the differing form of a protective structure and its relationship to an edge trimmer are given in figs 4A- 11B. The structures can also be used on different types of drill.
Abstract:
An expandable apparatus for use in a borehole includes a tubular body having at least one opening extending between a longitudinal bore of the tubular body and an outer surface of the tubular body and at least one member positioned within the at least one opening of the tubular body. The member is configured to move between a retracted position and an extended position. An actuation structure is positioned within the tubular body. The actuation structure is coupled to the at least one member and is configured to move the at least one member from the retracted position to the extended position responsive to a flow rate of drilling fluid passing through the longitudinal bore.