A downhole drill bit, of the type used to bore into the earth when searching for or extracting subterranean resources, may comprise a working face opposite an attachment end and an opening passing from the attachment end through to the working face. A protrusion on one end of a bottom hole assembly may extend through the opening and be exposed at the working face when the drill bit is attached to the end of the bottom hole assembly. In various embodiments the exposed portion of the protrusion may house conduits or nozzles for handling fluids; sensors, transmitters or wires for handling electrical signals; or mechanical hammers, motors or cutters for degrading an earthen formation. In this way, the protrusion may bring such elements from the bottom hole assembly to the working face of the drill bit.

The present disclosure describes various embodiments, as well as features and aspects thereof, of an improved drill bit assembly for a percussion boring system. More specifically, one non-limiting embodiment of an improved drill bit assembly for a percussion boring system comprises a bit and a product engagement member. The bit comprises a slant faced head and at least one exhaust port. The product engagement member comprises a product coupling portion and at least one fluid restriction portion. This improved drill bit assembly is such that, when the product engagement member is detachably engaged with the slant faced head of the bit, a first portion of the fluid stream expelled from the bit is directed substantially forward of the slant faced head and a second portion of the fluid stream is directed substantially rearward from the slant faced head.

The present disclosure describes various embodiments, as well as features and aspects thereof, of an improved drill bit assembly for a percussion boring system. More specifically, one non-limiting embodiment of an improved drill bit assembly for a percussion boring system comprises a bit and a product engagement member. The bit comprises a slant faced head and at least one exhaust port. The product engagement member comprises a product coupling portion and at least one fluid restriction portion. This improved drill bit assembly is such that, when the product engagement member is detachably engaged with the slant faced head of the bit, a first portion of the fluid stream expelled from the bit is directed substantially forward of the slant faced head and a second portion of the fluid stream is directed substantially rearward from the slant faced head.

An earth-boring tool includes a tool body having an aperture therein defining a nozzle port, a nozzle or nozzle assembly disposed in the nozzle port, and a shape memory material disposed adjacent a surface of at least one component of the nozzle or nozzle assembly. The shape memory material retains at least one component of the nozzle or nozzle assembly by a threadless connection. The threadless connection includes mechanical interference between the shape memory material, the at least one component of the nozzle or nozzle assembly, and the tool body or another component of the nozzle or nozzle assembly. The shape memory material is formulated and configured to transform from a first phase and a first shape upon heating and to transform from a second phase and a second shape upon cooling.

An earth-boring tool includes a tool body having an aperture therein defining a nozzle port, a nozzle or nozzle assembly disposed in the nozzle port, and a shape memory material disposed adjacent a surface of at least one component of the nozzle or nozzle assembly. The shape memory material retains at least one component of the nozzle or nozzle assembly by a threadless connection. The threadless connection includes mechanical interference between the shape memory material, the at least one component of the nozzle or nozzle assembly, and the tool body or another component of the nozzle or nozzle assembly. The shape memory material is formulated and configured to transform from a first phase and a first shape upon heating and to transform from a second phase and a second shape upon cooling.

Disclosed are systems and methods of balancing weight and hydraulic energy distribution between downhole cutting tools. One system includes a drill bit arranged at a distal end of the bottom-hole assembly, a first sensor sub arranged proximate to the drill bit and configured to monitor weight-on-bit, a reamer axially-offset from the drill bit on the bottom-hole assembly, a second sensor sub arranged proximate to the reamer and configured to monitor weight-on-reamer, and a communications module communicably coupled to both the first and second sensor subs and configured to receive and process the weight-on-bit and the weight-on-reamer and adjust a hydraulic energy input to at least one of the drill bit and the reamer when a ratio between the weight-on-bit and the weight-on-reamer surpasses a predetermined operating threshold.

Disclosed are systems and methods of balancing weight and hydraulic energy distribution between downhole cutting tools. One system includes a drill bit arranged at a distal end of the bottom-hole assembly, a first sensor sub arranged proximate to the drill bit and configured to monitor weight-on-bit, a reamer axially-offset from the drill bit on the bottom-hole assembly, a second sensor sub arranged proximate to the reamer and configured to monitor weight-on-reamer, and a communications module communicably coupled to both the first and second sensor subs and configured to receive and process the weight-on-bit and the weight-on-reamer and adjust a hydraulic energy input to at least one of the drill bit and the reamer when a ratio between the weight-on-bit and the weight-on-reamer surpasses a predetermined operating threshold.

A tool component comprising a wear part covered at least in part by a connection member, the wear part having a specified hardness and the connection member being a metal or alloy, and the wear part comprising a surface that includes one or more depressions or projections therefrom, and the connection member having been pressed against that surface so that at least the surface of the connection member that faces the wear part surface follows the profile of the wear part, whereby relative movement between the wear part and connection member is substantially prevented. The metal or alloy connection member may be readily attached to a tool body for example by brazing of the like. The wear part may comprise a material that is not readily brazeable, for example a ceramic material or a cermet or a superhard material or a composite of such materials.

A drill bit comprises a bit body having a body face. A plurality of fixed blades extends from the bit body. Each of the plurality of fixed blades has a leading face and a trailing face. A plurality of nozzles is disposed on the body face to flow drilling fluid out of the bit body. A plurality of flow guides direct a portion of the drilling fluid away from the bit body. Each of the plurality of flow guides extends longitudinally from the body face, and along the leading face of one of the plurality of fixed blades.

A drill bit comprises a bit body having a body face. A plurality of fixed blades extends from the bit body. Each of the plurality of fixed blades has a leading face and a trailing face. A plurality of nozzles is disposed on the body face to flow drilling fluid out of the bit body. A plurality of flow guides direct a portion of the drilling fluid away from the bit body. Each of the plurality of flow guides extends longitudinally from the body face, and along the leading face of one of the plurality of fixed blades.