A downhole motor includes a driveshaft assembly including a driveshaft housing and a driveshaft rotatably disposed within the driveshaft housing, and a bearing assembly including a bearing housing and a bearing mandrel rotatably disposed within the bearing housing, wherein the bearing mandrel is configured to couple with a drill bit, wherein the bearing assembly is configured to provide a first flowpath extending into a central passage of the bearing mandrel from an annulus formed between the bearing mandrel and the bearing housing and a second flowpath separate from the first flowpath, that extends through a bearing of the bearing assembly that is disposed radially between the bearing mandrel and the bearing housing, wherein a plurality of rotary seals are positioned radially between the bearing mandrel and the bearing housing to form an sealed chamber that is spaced from the bearing of the bearing assembly.

A cam system for use with a rotary steerable system, the cam system includes a housing, a cam positioned at least partially within the housing, and a solid cam shaft engaged with the cam and positioned at least partially within the housing, wherein the cam is operable to adjust an azimuthal orientation of the solid cam shaft.

A drilling assembly includes a hydraulic amplifier assembly, a driver, a bearing housing, and a shaft. The hydraulic amplifier assembly is configured to increase a pressure of a drilling fluid so as to produce a pressurized drilling fluid. The driver is driven by the pressure of the drilling fluid and is configured to rotate a drill bit. The bearing housing is coupled to the driver. The shaft extends through the bearing housing and is configured to be coupled to the drill bit. The shaft is driven to rotate by the driver. The hydraulic amplifier is configured to deliver the pressurized drilling fluid to the drill bit.

A valve apparatus having a valve body configured with a flow passage. There is a main piston movably disposed within the flow passage, and configured to move to and from a first piston position to a second piston position. The valve apparatus also has a movable member movably disposed within the valve body, the movable member comprising: a no-go position for stopping movement of the main piston, and a go position to facilitate movement of the main piston.

An apparatus for drilling curved and straight sections of a wellbore is disclosed that in one non-limiting embodiment includes a drilling assembly configured to include a drill bit at an end thereof that can be rotated by a drive in the drilling assembly and by the rotation of the drilling assembly, and wherein the drilling assembly includes: a deflection device that (i) tilts a section of the drilling assembly within a selected plane when the drilling assembly is substantially rotationally stationary to allow drilling of a curved section of the wellbore by rotating the drill bit by the drive; and (ii) straightens the section of the drilling assembly when the drilling assembly is rotated to allow drilling of a straight section of the wellbore.

A system for an adjustably flexible downhole tool includes first and second connector ends each configured to connect to adjacent downhole tools and a shaft extending between the first and second connector ends. The shaft is configured to bend in response to passing through curved portions of a wellbore. The adjustably flexible downhole tool also includes an outer sleeve disposed around at least a portion of the shaft and extending from the first connector end in a direction toward the second connector end and at least one adjustable member configured to move axially, with respect to the shaft, from a first position to a second position to increase bending stiffness and/or torsional stiffness of the adjustably flexible downhole tool. The at least one adjustable member at least partially restrains bending of the shaft in the second position.

Pad force is one of the major parameters in some drilling systems, such as a RSS, that affect steering decisions during drilling. The disclosure recognizes that the pad force can change during drilling due to, for example, unintentional leaking through a pad seal that has been damaged due to the wear and tear of drilling. With a decrease in the pad force, the steering capability of the drilling tool can be compromised. As such, the disclosure provides a method and system that determines pad force information in real time for controlling drilling. The pad force information can be determined based on sensor data, component data, and drilling data. An estimated pad force is one example of the pad force information that can be calculated and used to direct a drilling operation.

An example embodiment of a pipe-in-pipe electric motor assembly includes a drilling string that includes an inner pipe, an outer pipe, and an electric motor. The electric motor is provided with power supplied by the inner pipe and the outer pipe acting at least as conductors. A latching mechanism connects the drilling string and an electric motor output shaft. The electric motor output shaft is driven by the electric motor. The latching mechanism prevents the electric motor output shaft from rotating slower than the drilling string and associated methods.

Adjustment of the angle of a bent sub or other steering feature in a drill string relative to a reference angle of a downhole sensor is facilitated by a rotatable coupling between the bent sub and the sensor. The rotatable coupling may be rotated to align the high side with a reference indicium and locked at the set angle. Rows of ceramic balls retained in circumferential channels may be provided to permit rotation while carrying tensile and compressional forces. Calibration of the sensor is facilitated and opportunities for certain measurement errors are eliminated. An embodiment provides a mechanism for locking the rotatable coupling at a desired angle. The embodiment comprises a ring with teeth that engage a downhole portion of the coupling and depressions that engage an uphole portion of the coupling.

A disclosed mud motor includes a rotor head, a motor block, a hollow rotor, an inlet shaft, and an outlet shaft. In the operation of one embodiment, a pressurized drilling mud enters the rotor head through the inlet shaft. Some or all of the drilling mud is directed through an included inlet passage onto pistons which are included in the motor block and disposed concentrically around the outlet shaft. A downward action of the pistons resulting from the drilling mud causes an included power plate to rotate. Rotation of the power plate causes the hollow rotor and the rotor head to also rotate. The hollow rotor may be attached to a drilling implement. Rotation of the power plate also causes some or all of the drilling mud directed onto the pistons to be discharged into the outlet shaft through an included discharge passage. During the operation of one embodiment of the mud motor, the pistons do not rotate around the outlet shaft, but instead remain substantially in their original concentric alignment.