Abstract: A completions bit for use in a wellbore includes: a shank having a coupling formed at an upper end thereof; a body mounted to a lower end of the shank; and a cutting face forming a lower end of the bit. The cutting face includes: a blade protruding from the body; a tangentially oriented leading cutter mounted to a bearing face of the blade adjacent to a leading edge of the blade at an inner portion of the cutting face; and a radially oriented leading cutter mounted to the bearing face of the blade in proximity to the leading edge thereof at an outer portion of the cutting face.

Abstract: A completions bit for use in a wellbore includes: a shank having a coupling formed at an upper end thereof; a body mounted to a lower end of the shank; and a cutting face forming a lower end of the bit. The cutting face includes: a blade protruding from the body; a tangentially oriented leading cutter mounted to a bearing face of the blade adjacent to a leading edge of the blade at an inner portion of the cutting face; and a radially oriented leading cutter mounted to the bearing face of the blade in proximity to the leading edge thereof at an outer portion of the cutting face.

Abstract: A bit for downhole use includes: a leg having a mid shirttail and a lower bearing shaft; a roller cone rotatably mounted to the bearing shaft; a row of gage cutters, a row of inner cutters, and a nose cutter, each cutter mounted to or formed on the roller cone; and a gland formed in an inner surface of the roller cone. The gland has: a face; an outer surface; a fillet connected to the outer surface; a corner connecting the face and the outer surface; and an elastomeric o-ring captured in the gland and squeezed between the outer surface and the bearing shaft. A radius of the fillet is greater than one-half of a cross-sectional diameter of the o-ring.

Abstract: A hybrid bit for use in a wellbore includes: a body having a shank for connection to a drilling motor or drill pipe and a plurality of legs attached to the shank; and a plurality of cutting structures. The cutting structures include a roller cone mounted to a first one of the legs and a fixed mill mounted to a second one of the legs and including a pad dressed with a cermet material.

Abstract: A hybrid bit for use in a wellbore includes: a body having a shank for connection to a drilling motor or drill pipe and a plurality of legs attached to the shank; and a plurality of cutting structures. The cutting structures include a roller cone mounted to a first one of the legs and a fixed mill mounted to a second one of the legs and including a pad dressed with a cermet material.

Abstract: A roller-mill bit for use in a wellbore includes: a body having a coupling formed at an upper end thereof and a plurality of lower legs; a plurality of roller disks, each roller disk secured to a bearing shaft of a respective leg for rotation relative thereto; a row of crushers mounted around each roller disk; and a fixed mill mounted to the bearing shafts and comprising a pad for each roller disk. Each pad is dressed with a cermet material.

Abstract: A bit for downhole use includes: a leg having a mid shirttail and a lower bearing shaft; a roller cone rotatably mounted to the bearing shaft; a row of gage cutters, a row of inner cutters, and a nose cutter, each cutter mounted to or formed on the roller cone; and a gland formed in an inner surface of the roller cone. The gland has: a face; an outer surface; a fillet connected to the outer surface; a corner connecting the face and the outer surface; and an elastomeric o-ring captured in the gland and squeezed between the outer surface and the bearing shaft. A radius of the fillet is greater than one-half of a cross-sectional diameter of the o-ring.