A downhole cutting apparatus includes a cutter block. The cutter block includes a formation facing surface with cutting elements coupled thereto. The cutting elements are arranged such that at least one cutting element has a different exposure relative to the formation facing surface than at least one other cutting element. In some embodiments, a row of cutting elements may have a gradually changing exposure. The exposure may change such that cutting elements nearer the gauge of the cutter block have less exposure than cutting elements farther from the gauge of the cutter block. In additional embodiments, an underreamer may include multiple cutter blocks. The cutter blocks may each have a different configuration in a backreaming portion, gauge portion, underreaming portion, any part thereof, or in a combination of the foregoing.

A wellbore assembly includes a drill string, a drill bit, and a reamer assembly. The reamer assembly is coupled to the drill string uphole of the drill bit and includes a side cutter. The reamer assembly includes a spring that moves the side cutter from an extended position, in which the side cutter is retained by a portion of the reamer assembly against inward movement and in which the cutter defines a first drilling diameter greater than a drilling diameter of the drill bit, to a retracted position in which the portion of the reamer assembly has been broken by a shear force applied by the side cutter under a weight on bit applied against an inner component of the casing. In the retracted position, the side cutter is housed within the housing and defines a drilling diameter equal to or less than the drilling diameter of the drill bit.

A bit for drilling a wellbore includes: a shank having a coupling formed at an upper end thereof; a body removably attached to a lower end of the shank and having a blade receptacle formed therethrough; a blade fixed to the body; a plurality of superhard cutters mounted along a leading edge of the fixed blade; a blade disposed in the blade receptacle and longitudinally movable relative to the body between an extended position and a retracted position; a plurality of superhard cutters mounted along a leading edge of the movable blade; and a spring disposed between the shank and the movable blade and biasing the movable blade toward the extended position.

A bit for drilling a wellbore includes: a shank having a coupling formed at an upper end thereof; a body removably attached to a lower end of the shank and having a blade receptacle formed therethrough; a blade fixed to the body; a plurality of superhard cutters mounted along a leading edge of the fixed blade; a blade disposed in the blade receptacle and longitudinally movable relative to the body between an extended position and a retracted position; a plurality of superhard cutters mounted along a leading edge of the movable blade; and a spring disposed between the shank and the movable blade and biasing the movable blade toward the extended position.

Tools and methods are described for removing a packer beyond a restriction in a casing of a wellbore. A packer milling tool includes: a milling body with an outer diameter; milling blocks positioned at intervals around a circumference of the milling body, each milling block pivotably attached to the milling body and pivotable between a running position and a milling position; and a wash pipe extending from a downhole end of the milling body. The milling blocks have a rotational circumference with a rotational diameter that is less than the outer diameter of the milling body when in the running position and the rotational diameter is more than the outer diameter of the milling body and less than the inner diameter of the casing when in the milling position.

The multifunction wellbore conditioning tool (100, 200, 300) is installed in the bottom hole assembly of a drill string and performs the functions of a cutting tool, keyseat wiper, roller reamer, keyseat wiper, and stabilizer during drilling operations, precluding the need for multiple different tools in the drill string. The tool (100, 200, 300) has a working sleeve (114, 214, 314) captured concentrically on the driveshaft (102, 202, 302) between opposed spring sets (134, 136; 234, 236; 334, 336). The sleeve (114, 214, 314) remains rotationally stationary about the rotating driveshaft (102, 202, 302) when in its central or neutral position on the driveshaft (102, 202, 302). When the sleeve (114, 214, 314) shifts axially on the driveshaft (102, 202, 302) it engages a clutch mechanism that allows it to rotate with the driveshaft (102, 202, 302) so that the rotating working sleeve (114, 214, 314) conditions the borehole.

Bottom hole assemblies for deploying fabric can include: a body configured to be attached to a drill pipe; a control tube disposed inside the body at a position controlled by engagement of a cam with a continuous guide path; a set tube, the set tube and the body together defining a pressure chamber with the body defining an inlet port extending between the interior cavity and pressure chamber, the set tube movable between a rolling position and a reaming position; a reamer assembly with at least one first articulated arm with extending between first attachment point on the body and the set tube; and a roller assembly with: at least one second articulated arm extending between the set tube and a second attachment point on the body; and a roller positioned at a joint of each second articulated arm.

Tools and methods are described for removing a packer beyond a restriction in a casing of a wellbore. A packer milling tool includes: a milling body with an outer diameter; milling blocks positioned at intervals around a circumference of the milling body, each milling block pivotably attached to the milling body and pivotable between a running position and a milling position; and a wash pipe extending from a downhole end of the milling body. The milling blocks have a rotational circumference with a rotational diameter that is less than the outer diameter of the milling body when in the running position and the rotational diameter is more than the outer diameter of the milling body and less than the inner diameter of the casing when in the milling position.

Bottom hole assemblies with a combined roller-underreamer assembly can include: a body configured to be attached to a drill pipe; an uphole ring attached to the body; a downhole ring attached to the body between the uphole ring and the downhole end of the body; a sliding ring mounted around the body between the uphole ring and the downhole ring; a set tube slidably mounted around the body between the uphole ring and the sliding ring; a reamer assembly with at least one first articulated arm with extending between the uphole ring and the downhole end of the set tube; and a roller assembly with: at least one second articulated arm extending between the uphole end of the set tube and the sliding ring; and a rolling positioned at a joint of each second articulated arm.

Bottom hole assemblies for deploying fabric can include: a body configured to be attached to a drill pipe; a control tube disposed inside the body at a position controlled by engagement of a cam with a continuous guide path; a set tube, the set tube and the body together defining a pressure chamber with the body defining an inlet port extending between the interior cavity and pressure chamber, the set tube movable between a rolling position and a reaming position; a reamer assembly with at least one first articulated arm with extending between first attachment point on the body and the set tube; and a roller assembly with: at least one second articulated arm extending between the set tube and a second attachment point on the body; and a roller positioned at a joint of each second articulated arm.