A rotary drill bit for use with a horizontal directional drill string. A coupler at a proximal axial end is configured to attach the rotary drill bit to a drill head at a distal end of the drill string. A cutting portion at a distal axial end is provided with a plurality of vanes with respective cutters that operate to cut a hole in earth when the rotary drill bit is rotated about a central axis. The plurality of vanes project radially outwardly from a surface of the cutting portion such that the surface forms respective troughs circumferentially interspersed with the plurality of vanes. A plurality of engagement features is positioned axially within the cutting portion and radially inward of an outer cutting diameter to facilitate attachment of a product pullback device between the plurality of vanes without removing the rotary drill bit, or any portion thereof, from the drill head.

Methods for forming a polycrystalline diamond compact (PDC) drill bit from catalyst-free synthesized polycrystalline diamonds are described. The polycrystalline diamonds are deposited within a mold. In some cases, a matrix body material is deposited within the mold, and an infiltration process is performed to bond the polycrystalline diamonds to the matrix body material to form the PDC drill bit. In some cases, a drill bit body is formed within the mold, and forming the drill bit body within the mold includes depositing a layer of matrix body material particles within the mold, depositing an adhesive ink within the mold, and curing the adhesive ink. In some cases, a sintering process is performed after forming the drill bit body to remove at least a portion of the adhesive ink and increase a density of the drill bit body to form the PDC drill bit.

A piston for use in a rotary steerable system includes a body formed from a first material. A sealing surface extends around the circumferential wall of the body. The sealing surface is formed from a plurality of layers of a second material. The second material is harder than the first material. The piston can be within a downhole piston assembly that also includes a housing, and the piston being longitudinally movable in a bore in the housing. A method for producing a piston includes preparing a piston formed from a first material, with the piston including a first end. A sealing surface is applied to the piston using laser cladding, with the sealing surface including a second material harder than the first material. The sealing surface is finished to a sealing surface diameter.

A piston for use in a rotary steerable system includes a body formed from a first material. A sealing surface extends around the circumferential wall of the body. The sealing surface is formed from a plurality of layers of a second material. The second material is harder than the first material. The piston can be within a downhole piston assembly that also includes a housing, and the piston being longitudinally movable in a bore in the housing. A method for producing a piston includes preparing a piston formed from a first material, with the piston including a first end. A sealing surface is applied to the piston using laser cladding, with the sealing surface including a second material harder than the first material. The sealing surface is finished to a sealing surface diameter.

The disclosure provides a drill bit including a bit body and a blade extending from the bit body. The blade includes a first element protruding from a surface of the blade and a second element protruding from the surface of the blade. The first element and the second element are each configured to extend or retract relative to the surface of the blade and are coupled to each other such that when the second element retracts relative to the surface of the blade, the first element extends relative to the surface of the blade. The first element is disposed within a first pocket formed in the surface of the blade, and the second element is disposed within a second pocket formed in the surface of the blade. A communication channel is formed between the first pocket and the second pocket.

A cutting element has a cutting face with a geometry including at least one protrusion spaced a radial distance apart from an edge of the cutting element, the edge extending around an entire periphery of the cutting face, and a lower portion extending within the distance between the at least one protrusion and the edge, wherein a lower portion axial height measured between the edge and a base of the at least one protrusion is less than 30 percent of a greatest axial height of the at least one protrusion measured between the base of the at least one protrusion and an axially highest point of the at least one protrusion.

An earth-boring tool may include a blade having a face surface, a cutting edge, and a rotationally leading surface. The earth-boring tool may additionally include at least one fluid port extending through the blade, and a fluid port manifold having an opening at a first end and a plurality of openings along a length providing fluid communication between the at least one fluid port and a primary fluid passage of the earth-boring tool. An additional earth-boring tool may include a fluid port manifold located in the tool body and a plurality of fluid port sleeves, each fluid port sleeve of the plurality of fluid port sleeves extending into a corresponding opening of a plurality of openings along the length of the fluid port manifold.

In a drill bit which has hard-faced cutting or gauge protection elements positioned to be in direct contact with subterranean formation as the bit is rotated, at least one of these elements includes a window positioned to be in direct contact with the formation or cuttings from the formation as the bit rotates and moves forward to drill into the formation. Electromagnetic radiation with wavelength in the range from 100 nm to 2600 nm is transmitted through the window to the formation in contact with the window. Electromagnetic radiation such as fluorescence that returns through the same window is received by a spectrometer. The source and receiver of electromagnetic radiation are both accommodated within the downhole drilling equipment but spaced from the windowed element. The electromagnetic radiation travels along light guides from the source to the window and from the window to the receiver.

In a drill bit which has hard-faced cutting or gauge protection elements positioned to be in direct contact with subterranean formation as the bit is rotated, at least one of these elements includes a window positioned to be in direct contact with the formation or cuttings from the formation as the bit rotates and moves forward to drill into the formation. Electromagnetic radiation with wavelength in the range from 100 nm to 2600 nm is transmitted through the window to the formation in contact with the window. Electromagnetic radiation such as fluorescence that returns through the same window is received by a spectrometer. The source and receiver of electromagnetic radiation are both accommodated within the downhole drilling equipment but spaced from the windowed element. The electromagnetic radiation travels along light guides from the source to the window and from the window to the receiver.

Tools, for example, fixed cutter drill bits, may be manufactured to include hard composite portions having reinforcing particles dispersed in a continuous binder phase and auxiliary portions that are more machinable than the hard composite portions. For example, a tool may include a hard composite portion having a machinability rating 0.2 or less; and an auxiliary portion having a machinability rating of 0.6 or greater in contact with the hard composite portion. The boundary or interface between the hard composite portion and the auxiliary portion may be designed so that upon removal of the most or all of the auxiliary portion the resultant tool has a desired geometry without having to machine the hard composite portion.