Abstract: A bottom hole assembly to directionally drill a subterranean formation includes a drill bit, a stabilizer assembly located proximate to and behind the drill bit, a drilling assembly comprising a drive mechanism and a directional mechanism, and a flex member. Optionally, the flex member may be located between the drilling assembly and the stabilizer assembly or an integral to a housing of the drilling assembly. A method to drill a formation includes positioning a stabilizer assembly behind a drill bit and positioning a flex member between an output shaft of a drilling assembly and the stabilizer assembly. The method preferably includes rotating the drill bit, stabilizer assembly, and flex member with a drilling assembly and directing the trajectory of the drill bit and stabilizer assembly with a directional mechanism of the drilling assembly.

Abstract: An expandable drilling apparatus is deployed upon a distal end of a drillstring and includes a cutting head and a substantially tubular main body adjacent the cutting head providing a plurality of axial recesses configured to receive arm assemblies configured to translate between a retracted and an extended position. A flow switch actuates the arm assemblies when a drilling fluid pressure exceeds an activation value and the drilling apparatus includes a biasing member to reset the arm assemblies when the drilling fluid pressure falls below a reset value.

Abstract: A bit retainer system is disclosed. The bit retainer system includes a bit having a head and a shank, a driver sub disposed around the shank of the bit and adapted to engage a hammer case, a bit retainer disposed around the shank of the bit and abutting an upper end of the driver sub, and a secondary retainer disposed around the bit retainer.

Abstract: A bottom hole assembly includes a drill bit, a stabilized underreamer assembly located behind the drill bit, and a drilling assembly. A method to drill a formation includes positioning a stabilized underreamer assembly behind a drill bit, positioning a drilling assembly behind the stabilized underreamer assembly, and rotating the drill bit and stabilized underreamer assembly with the drilling assembly. A stabilized underreamer located between a directional drilling assembly and a drill bit includes at least one arm assembly extending from the stabilized underreamer assembly, wherein the arm assembly includes a stabilizer portion and an underreamer cutting structure.

Abstract: A bit retainer system comprising a casing, a driver sub adapted to be disposed around a shank of a bit, and a bit retainer. The driver sub comprises a threaded connector, a threaded pin end configured to engage with the hammer case, and a stop. The bit retainer comprises a load carrying threaded connector configured to engage with the threaded connector of the driver sub, and a catch thread configured to retain the head of a bit to the system.