A tool for use in a borehole to perform a milling, under reaming, or other cutting operation includes a tool body configured for rotation about its longitudinal axis, within the borehole, and a set of cutters, the set including two or more cutters which, at least in a deployed configuration, extend outwardly from the tool body and are fixedly coupled together whilst being pivotally coupled to the tool body substantially on said axis so that the cutters rotate with the tool body whilst being pivotable together relative to the tool body during cutting.

A tool for use in a borehole to perform a milling, under reaming, or other cutting operation includes a tool body configured for rotation about its longitudinal axis, within the borehole, and a set of cutters, the set including two or more cutters which, at least in a deployed configuration, extend outwardly from the tool body and are fixedly coupled together whilst being pivotally coupled to the tool body substantially on said axis so that the cutters rotate with the tool body whilst being pivotable together relative to the tool body during cutting.

An apparatus for use downhole is disclosed that, in one configuration includes a downhole tool configured to operate in an active position and an inactive position and an actuation device, which may include a control unit. The apparatus includes a telemetry unit that sends a first pattern recognition signal to the control unit to move the tool into the active position and a second pattern recognition signal to move the tool into the inactive position. The apparatus may be used for drilling a subterranean formation and include a tubular body and one or more extendable features, each positionally coupled to a track of the tubular body, and a drilling fluid flow path extending through a bore of the tubular body for conducting drilling fluid therethrough. A push sleeve is disposed within the tubular body and coupled to the one or more features. A valve assembly is disposed within the tubular body and configured to control the flow of the drilling fluid into an annular chamber in communication with the push sleeve; the valve assembly comprising a mechanically operated valve and/or an electronically operated valve. Other embodiments, including methods of operation, are provided.

Expandable reamers may include a housing and at least one blade supported by the housing. The at least one blade may be movable between an extended position and a retracted position. The at least one blade may be in the retracted position when a first actuation member is in a first longitudinal position and a second actuation member sleeve is affixed to the first actuation member. The at least one blade may be movable to the extended position when the first actuation member is in a second longitudinal position and the second actuation member is affixed to the first actuation member. The at least one blade may be in the retracted position when the first actuation member is in the second longitudinal position and the second actuation member obstructs an opening in a sidewall of the first actuation member.

A method of hydraulically activating a mechanically operated wellbore tool in a bottom hole assembly includes: holding moveable elements of the wellbore tool in an unactivated position using a shear pin; inserting one or more drop balls into a drilling fluid; and flowing the drilling fluid with the drop balls to a flow orifice located in or below the wellbore tool. The flow orifice is at least partially plugged with the drop balls to restrict fluid flow and correspondingly increases the hydraulic pressure of the drilling fluid. The hydraulic pressure is increased to a point beyond the rating of the shear pin, thereby causing the shear pin to shear and allowing the moveable elements of the tool to move to an activated position.

Expandable reamers are configured to operate in a first, retracted state in which a plurality of blades is in a retracted position when a sliding sleeve is in a first sleeve position and a seat is in a first seat position, to operate in a second, extended state in which the plurality of blades is movable to an extended position when the sliding sleeve is in at least a second sleeve position and the seat is in the first seat position, and to operate in a third, retracted state in which the plurality of blades is returned to the retracted position when the sliding sleeve is in the at least a second position and the seat is in a second seat position.

A downhole intelligent reamer controller detects the difference between rotary drilling and sliding drilling, responds appropriately and quickly to multiple changes between rotary drilling and sliding drilling that may occur several times each stand of pipe. Additional controls prevent deployment of reamer members at inappropriate times such as when drilling out cement, testing, and running in and out of the wellbore. In one embodiment, a separate modular control sub is disclosed that may be utilized with and/or removably secured to an expandable reamer and/or other types of downhole tools.

A downhole intelligent reamer controller detects the difference between rotary drilling and sliding drilling, responds appropriately and quickly to multiple changes between rotary drilling and sliding drilling that may occur several times each stand of pipe. Additional controls prevent deployment of reamer members at inappropriate times such as when drilling out cement, testing, and running in and out of the wellbore. In one embodiment, a separate modular control sub is disclosed that may be utilized with and/or removably secured to an expandable reamer and/or other types of downhole tools.

A drilling assembly comprises a drill bit and a cutting assembly. The drilling assembly forms a longitudinal center axis. The drill bit and cutting assembly fastened to a rotatable spline drive assembly. The cutting assembly being resiliently displaceable to the drill bit along the center axis such that in a first position the drill bit is surrounded by the cutting assembly and in a second position a free end portion of the drill bit projects beyond the cutting assembly along the center axis. The cutting assembly comprises an endmill which comprises a central through hole which is complementary to the outer diameter of the drill bit. A method for cutting swarfs created by drilling with the endmill is described

A downhole tool includes at least a pilot section, a first expansion section, and a second expansion section. The pilot section has a plurality of cutting elements to cut a pilot hole. Each of the expansion sections has a plurality of cutting elements to successively expand the pilot hole to achieve a final wellbore radius. The pilot section, first expansion section, and second expansion section each have one or more stabilizer pads on respective gages to stabilize the downhole tool during wellbore creation.