Methods, systems, and apparatus for imparting and limiting hypocycloidal, lateral, and torsional forces onto drill bits are provided, including hypocycloidal bearings for limiting hypocycloidal motion, lateral impulse mechanisms for imparting lateral movement to a drill bit, and torsional impulse mechanisms for imparting torsional movement to a drill bit. The methods systems, and apparatus may decrease friction, increase drilling efficiency, and provide additional benefits to drilling systems.

A safety catch assembly design to prevent loss of drilling components during downhole operation is disclosed. The safety catch assembly can include a lower inner radial bearing comprising a catch ring retention zone. The safety catch assembly can also include one or more catch rings removably disposed in the catch ring retention zone, including a first catch ring having one or more ridges about its inner diameter and a second catch ring having one or more ridges about its inner diameter. In a locked position, the catch rings can retain the drilling components during a failure event.

Embodiments of the invention relate to bearing apparatuses in which one bearing surface of the bearing apparatus includes diamond, while another bearing surface includes a non-diamond superhard material (e.g., silicon carbide). For example, a bearing apparatus may include a bearing stator assembly and a bearing rotor assembly. The bearing stator assembly and bearing rotor assembly each include a support ring and one or more superhard bearing elements generally opposed to one another. The bearing surface(s) of the rotor or stator may include diamond, while the bearing surface(s) of the other of the rotor or stator do not include diamond. Another bearing apparatus may include both thrust- and radial bearing components. The generally opposed thrust-bearing elements may include diamond, while the generally opposed radial bearing elements may not include diamond, but include a non-diamond superhard material, such as silicon carbide.

A sealed bearing system has a pressure-retaining seal separating two lubricating chambers, one pressure balanced to the outside and the other pressure balanced to the inside. The pressure retaining seal may be a non pumping seal. Radial bearings may be mounted near either axial side of the seal to prevent deflection. The pressure-retaining seal may include a flange and the flange may be axially compressed between a seal carrier and a portion of an outer tubular to fix the seal to the outer tubular. The seal and seal carrier may be installed using a mandrel on which they are temporarily positioned in order to insert and install them into the outer tubular.

Methods and apparatus according to which a first valve is opened, or kept open, the first valve being part of a wellhead including a flow component above the first valve. The method may further include detecting a state of the first valve and, in response to detecting the state of the first valve, metering an amount of grease to the first valve. In addition, or instead, the method may further include opening, or keeping open, a second valve, the second valve being operably coupled to the wellhead and positioned above the flow component, and, after opening, or keeping open, each of the first and second valves, detecting whether the second valve is open or closed, in response to detecting that the second valve is open, preventing the first valve from being closed, and in response to detecting that the second valve is closed, allowing the first valve to be closed.

Methods and apparatus according to which a first valve is opened, or kept open, the first valve being part of a wellhead including a flow component above the first valve. The method may further include detecting a state of the first valve and, in response to detecting the state of the first valve, metering an amount of grease to the first valve. In addition, or instead, the method may further include opening, or keeping open, a second valve, the second valve being operably coupled to the wellhead and positioned above the flow component, and, after opening, or keeping open, each of the first and second valves, detecting whether the second valve is open or closed, in response to detecting that the second valve is open, preventing the first valve from being closed, and in response to detecting that the second valve is closed, allowing the first valve to be closed.

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 bearing assembly having independently rotatable concentric inner and outer tubes. A bearing chamber containing multiple bearings is disposed between the tubes, allowing thrust but not rotation to be transferred between them. The bearing chamber is sealed from the inside of the inner tube. To prevent high pressure fluid from leaking from the inner tube to an exterior of the tool through the bearing chamber, damaging components, a flow path is formed. An annular piston responds to high pressure within the bearing chamber and the inner tube, opening a flow path from the inner tube to the environment.

Bearing assemblies that include a plurality of polycrystalline diamond (“PCD”) bearing elements, bearing apparatuses including such bearing assemblies, and methods of operating and fabricating such bearing assemblies and apparatuses are disclosed. In an embodiment, the plurality of PCD bearing elements of one or more of the bearing assemblies disclosed herein include at least one first PCD bearing element. At least a portion of the first PCD bearing element exhibits a coercivity of about 125 Oersteds or more and a specific magnetic saturation of about 14 Gauss cm.sup.3/gram or less. The first PCD bearing element includes a bearing surface with at least one groove formed therein. In an embodiment, the plurality of PCD bearing elements also include at least one second PCD bearing element. The second PCD bearing element exhibits a coercivity that is less than and a specific magnetic saturation that is greater than the first PCD bearing element.