Abstract: A stabilizer for use in a wellbore may include a downhole tubular configured to couple to a downhole conveyance in a wellbore, as well as two or more helical blades extending radially outward from the downhole tubular. The two or more helical blades are oriented about the downhole tubular to form respective flow paths between adjacent blades. Further, each blade of the two or more helical blades may include a line-of-sight face and a gauge ramp. The line-of-sight face is formed adjacent a leading inner blade wall of the blade at a lower end of the blade and is angularly offset from the leading inner blade wall. The gauge ramp extends from an outer surface of the downhole tubular toward an outer blade surface of the blade proximate the lower end of the blade.

Abstract: A drilling system can be used to drill a borehole. The drilling system may include a first housing defining a main fluid flow path and a second housing defining a bypass flow path toward an annulus of a wellbore. A flow control choke may be positioned between the first housing and the second housing. The flow control choke may include a rotatable section and a stationary section that is stationary relative to the rotatable section. The stationary section may have a curved interface with the rotatable section for restricting a flow of a drilling fluid through the bypass flow path.

Abstract: A pulsed power drilling (PPD) component includes a functional gradient of material from a first portion to a second portion of the PPD component. The functional gradient of material provides a greater wear resistance of the first portion relative to the second portion and a greater electrical conductivity or resistivity of the second portion relative to the first portion.

Abstract: Systems and methods for cold-spraying coatings on rotors in motor assemblies for improving reliability of motor assembly use downhole in wellbores is provided. For example, a motor assembly can include a stator positioned downhole in a wellbore and rotor coupled to the wellbore. The rotor can include a base material and a first coating deposited onto the base material via cold spraying for reducing damage to the rotor. The first coating may include sprayed particles that have a melting point temperature that is higher than a temperature of a gas used in the cold spraying. In some examples, the rotor may include a second coating deposited onto the first coating via cold spraying, high velocity oxygen fuel coating, or high velocity air fuel. The first coating may have a first hardness that is less than a second hardness of the second coating.

Abstract: A downhole motor or pump assembly that includes a stator and a rotor rotatable within the stator. The stator includes a tubular housing and an overlay deposited by cold spray onto an interior of the housing to form overlay lobes along a first length of the stator. The downhole motor or pump may be used to perform downhole operations.

Abstract: Systems and methods for cold-spraying coatings on rotors in motor assemblies for improving reliability of motor assembly use downhole in wellbores is provided. For example, a motor assembly can include a stator positioned downhole in a wellbore and rotor coupled to the wellbore. The rotor can include a base material and a first coating deposited onto the base material via cold spraying for reducing damage to the rotor. The first coating may include sprayed particles that have a melting point temperature that is higher than a temperature of a gas used in the cold spraying. In some examples, the rotor may include a second coating deposited onto the first coating via cold spraying, high velocity oxygen fuel coating, or high velocity air fuel. The first coating may have a first hardness that is less than a second hardness of the second coating.

Abstract: Certain aspects and features relate to a drilling system usable to drill a borehole. The drilling system may include a first housing defining a main fluid flow path and a second housing defining a bypass flow path toward an annulus of a wellbore. A flow control choke may be positioned between the first housing and the second housing. The flow control choke may include a rotatable section and a stationary section that is stationary relative to the rotatable section. The stationary section may have a curved interface with the rotatable section for restricting a flow of a drilling fluid through the bypass flow path.

Abstract: A downhole motor or pump assembly that includes a stator and a rotor rotatable within the stator. The stator includes a tubular housing and an overlay deposited by cold spray onto an interior of the housing to form overlay lobes along a first length of the stator. The downhole motor or pump may be used to perform downhole operations.

Abstract: A pulsed power drilling (PPD) component includes a functional gradient of material from a first portion to a second portion of the PPD component. The functional gradient of material provides a greater wear resistance of the first portion relative to the second portion and a greater electrical conductivity or resistivity of the second portion relative to the first portion.

Abstract: A drill string for drilling a borehole. The drill string may include a downhole motor operable to rotate the drill string and a centralizer assembly. The centralizer assembly may include an outer housing, a lower sub threadably engaged with the outer housing, and a centralizer. The centralizer may include a single eccentric blade, an internal shoulder positioned between the outer housing and the lower sub, and an alignment profile to align the centralizer in an azimuthal position relative to the drill string. The centralizer may be retainable in the aligned azimuthal position by the alignment profile and the internal shoulder being engaged by the outer housing and the lower sub.

Abstract: A stabilizer for use in a wellbore may include a downhole tubular configured to couple to a downhole conveyance in a wellbore, as well as two or more helical blades extending radially outward from the downhole tubular. The two or more helical blades are oriented about the downhole tubular to form respective flow paths between adjacent blades. Further, each blade of the two or more helical blades may include a line-of-sight face and a gauge ramp. The line-of-sight face is formed adjacent a leading inner blade wall of the blade at a lower end of the blade and is angularly offset from the leading inner blade wall. The gauge ramp extends from an outer surface of the downhole tubular toward an outer blade surface of the blade proximate the lower end of the blade.

Abstract: A rotor catch system includes a catch stem having a proximal end coupled to a rotor of a mud motor system and a distal end positioned within a sub housing of a drill string, a catch feature having a top portion and a spindle portion extending from the top portion and coupled to the distal end of the catch stem, a housing catch feature extending radially inward from an inner surface of the sub housing, and a catch bushing positioned between the top portion of the catch feature and the housing catch feature. The housing catch feature restrains axial movement of the catch bushing in the active catch state via contact between the catch bushing and the housing catch feature, and the catch bushing restrains axial movement of the catch feature in the active catch state via contact between the catch feature and the catch bushing.

Abstract: Provided is a stabilizer for use in a wellbore. The stabilizer, in one example, includes a downhole tubular coupleable to a downhole conveyance in a wellbore. In accordance with this example, the stabilizer additionally includes two or more helical wellbore stabilizing elements extending radially outward from the downhole component, the two or more helical wellbore stabilizing elements shaped such that an annular flow area between leading edges of adjacent helical wellbore stabilizing elements and between trailing edges of adjacent helical wellbore stabilizing elements is variable along at least a portion of a length (L) of the two or more helical wellbore stabilizing elements, and such that an unobstructed axial flow path exists between the adjacent helical wellbore stabilizing elements along the length (L).

Abstract: A rotor catch system includes a catch stem having a proximal end coupled to a rotor of a mud motor system and a distal end positioned within a sub housing of a drill string, a catch feature having a top portion and a spindle portion extending from the top portion and coupled to the distal end of the catch stem, a housing catch feature extending radially inward from an inner surface of the sub housing, and a catch bushing positioned between the top portion of the catch feature and the housing catch feature. The housing catch feature restrains axial movement of the catch bushing in the active catch state via contact between the catch bushing and the housing catch feature, and the catch bushing restrains axial movement of the catch feature in the active catch state via contact between the catch feature and the catch bushing.

Abstract: A radial bearing for transmitting a radial load, including a first radial bearing component having an inner surface defining a bore and a second radial bearing component received within the bore of the first radial bearing component and having an outer surface. The first radial bearing component includes a plurality of first component wear resistant inserts arranged and mounted on the inner surface. The second radial bearing component includes a second component wear resistant coating on at least a portion of the outer surface. The first radial bearing component and the second radial bearing component interact to transmit the radial load between the first radial bearing component and the second radial bearing component.

Abstract: A wear resistant insert including a deposition substrate having an exterior surface, and a wear resistant layer deposited on the exterior surface of the deposition substrate. The wear resistant insert may further include a structure interface layer deposited on an exterior surface of the wear resistant layer. A method of forming a wear resistant insert including providing a deposition substrate having an exterior surface, and depositing a wear resistant layer on the exterior surface of the deposition substrate. The method may further include depositing a structure interface layer on an exterior surface of the wear resistant layer. The method may further include separating the wear resistant layer from the deposition substrate intact.

Abstract: Downhole tools such as bearing assemblies and stabilizers are described for withstanding abrasive and erosive wear in operation. These stabilizers and bearing assemblies employ wear-resistant hard materials such as TSP, PCD, leached WC, and SCD composite materials. A bond between a braze material and wear tiles constructed of a hard phase material may include a non-planar interface with the braze material. Self-lubricating materials may be provided within the braze material or the hard material in some instances.

Abstract: A radial bearing for transmitting a radial load, including a first radial bearing component having an inner surface defining a bore and a second radial bearing component received within the bore of the first radial bearing component and having an outer surface. The first radial bearing component includes a plurality of first component wear resistant inserts arranged and mounted on the inner surface. The second radial bearing component includes a second component wear resistant coating on at least a portion of the outer surface. The first radial bearing component and the second radial bearing component interact to transmit the radial load between the first radial bearing component and the second radial bearing component.

Abstract: Downhole tools such as bearing assemblies and stabilizers are described for withstanding abrasive and erosive wear in operation. These stabilizers and bearing assemblies employ wear-resistant hard materials such as TSP, PCD, leached WC, and SCD composite materials. A bond between a braze material and wear tiles constructed of a hard phase material may include a non-planar interface with the braze material. Self-lubricating materials may be provided within the braze material or the hard material in some instances.