Abstract: An apparatus for generating pressure pulses in a drilling fluid flowing through a bore of a downhole tubular. A housing containing a rotor is located in the bore. Drilling fluid flowing through the housing actuates rotation of the rotor relative to the housing, which in turn drives movement of an actuator valve assembly to vary flow of drilling fluid between the bore and an actuator chamber defined by the actuator valve assembly and the housing. The resulting variation in drilling fluid pressure within the actuator chamber actuates a pulse valve assembly to vary flow of drilling fluid through the housing and into the bore. The varying drilling fluid pressure may be used to induce a percussive effect in a drill bit assembly coupled to the downhole tubular.

Abstract: A cutter profile for a fixed cutter drill bit having a drill bit axis. The cutter profile includes a nose portion radially offset from the drill bit axis and surrounding the drill bit axis, a first cone-shaped depression centered on the drill bit axis and extending radially to the nose portion, and a second cone-shaped depression centered on the drill bit axis and extending radially toward the nose portion. A second depression diameter is smaller than a first depression diameter. A second depression maximum depth is greater than a first depression maximum depth. A second depression included angle is smaller than a first depression included angle.

Abstract: A drilling apparatus including a drill bit and a nutation device. The drilling apparatus is configured to enable the drill bit to be rotated at a rotation frequency while the nutation device simultaneously nutates the drill bit at a nutation frequency. The nutation device may include a vibrating device for imposing vibrations upon the drilling apparatus at a vibration frequency, thereby causing nutation of the drill bit at the nutation frequency. The drilling apparatus may include a tuning mechanism for tuning the vibration frequency of the vibrating device. A method including rotating a drill bit at a rotation frequency and simultaneously nutating the drill bit at a nutation frequency.

Abstract: An apparatus for generating pressure pulses in a drilling fluid flowing through a bore of a downhole tubular. A housing containing a rotor is located in the bore. Drilling fluid flowing through the housing actuates rotation of the rotor relative to the housing, which in turn drives movement of an actuator valve assembly to vary flow of drilling fluid between the bore and an actuator chamber defined by the actuator valve assembly and the housing. The resulting variation in drilling fluid pressure within the actuator chamber actuates a pulse valve assembly to vary flow of drilling fluid through the housing and into the bore. The varying drilling fluid pressure may be used to induce a percussive effect in a drill bit assembly coupled to the downhole tubular.

Abstract: A drilling apparatus including a housing, a drill bit having a head end, a connection end, and a bearing mandrel between the head end and the connection end, a bearing pack associated with the bearing mandrel and the housing for transmitting forces between the drill bit and the housing, the bearing pack including at least one bearing interposed between the bearing mandrel and the housing, and a drive mechanism connected with the connection end of the drill bit, for driving the drill bit.

Abstract: A downhole motor assembly which has a housing, a power section with a stator and a rotor contained within the housing. A proximal drive assembly is connected with a proximal rotor end, a distal drive assembly is connected with a distal rotor end, and a proximal thrust bearing is arranged between the housing of the proximal drive assembly. A distal thrust bearing is arranged between the housing and the distal drive assembly. An axial load decoupling device is in the distal drive assembly located longitudinally between the distal rotor end and the distal thrust bearing, and is used for separating axial loads imposed on the proximal thrust bearing from axial loads imposed on the distal thrust bearing.

Abstract: A fixed cutter drill bit having a bit axis and a gauge diameter. The drill bit includes a bit body having a proximal end, a distal end, and a plurality of blades extending from the distal end toward the proximal end. The blades define a cutting profile between the bit axis and the gauge diameter. The drill bit further includes a plurality of cutters attached to the blades in a cutter layout. The cutter layout may include a balanced cutter pattern extending from the bit axis toward the gauge diameter. The cutter layout may include one or more sets of shared cutters, wherein each set of shared cutters includes a trailing shared cutter and a leading shared cutter. The blades may define pairs of makeup surfaces and breaker surfaces. The drill bit may include a breaker upset for engaging with a device for supporting the drill bit.

Abstract: In a fixed cutter drill bit, a hybrid cutter with a cutting edge including a substantially continuous curve interrupted by at least one arc discontinuity. In a fixed cutter drill bit, a contoured cutter with a contoured cutting face including a raised shape, wherein the raised shape has a raised shape axis which is oblique to a drill bit body axis. In a cutter for a fixed cutter drill bit, a chamfer including a side bevel and a cutting face bevel, wherein a cutting face bevel length is at least two times a side bevel length.

Abstract: A drilling apparatus including a drill bit and a nutation device. The drilling apparatus is configured to enable the drill bit to be rotated at a rotation frequency while the nutation device simultaneously nutates the drill bit at a nutation frequency. The nutation device may include a vibrating device for imposing vibrations upon the drilling apparatus at a vibration frequency, thereby causing nutation of the drill bit at the nutation frequency. The drilling apparatus may include a tuning mechanism for tuning the vibration frequency of the vibrating device. A method including rotating a drill bit at a rotation frequency and simultaneously nutating the drill bit at a nutation frequency.

Abstract: A downhole motor assembly including a housing, a power section with a stator and a rotor contained within the housing, a proximal drive assembly connected with a proximal rotor end, a distal drive assembly connected with a distal rotor end, a proximal thrust bearing arranged between the housing and the proximal drive assembly, a distal thrust bearing arranged between the housing and the distal drive assembly, and an axial load decoupling device in the distal drive assembly located longitudinally between the distal rotor end and the distal thrust bearing, for separating axial loads imposed on the proximal thrust bearing from axial loads imposed on the distal thrust bearing.

Abstract: A drilling apparatus including a housing, a drill bit having a head end, a connection end, and a bearing mandrel between the head end and the connection end, a bearing pack associated with the bearing mandrel and the housing for transmitting forces between the drill bit and the housing, the bearing pack including at least one bearing interposed between the bearing mandrel and the housing, and a drive mechanism connected with the connection end of the drill bit, for driving the drill bit.