A PDC drill bit for use in downhole air drilling includes a body with a face for engaging a bottom of a hole being drilled and a gauge for engaging a side of the hole being drilled. The face includes a cone, a nose outward of the cone, a shoulder outward of the nose. The bit further includes channels formed in the face of the bit that extend from within the cone to the gauge. The channels define a plurality of blades separated by the channels. Each of the plurality of blades has a leading edge with PDC cutters mounted thereon. One or more of the channels are defined by two side walls and a bottom wall and has a length, width and depth. The width or depth remains substantially constant from a first point on its length within the cone to a second point within the shoulder.

A PDC drill bit for use in downhole air drilling includes a body with a face for engaging a bottom of a hole being drilled and a gauge for engaging a side of the hole being drilled. The face includes a cone, a nose outward of the cone, a shoulder outward of the nose. The bit further includes channels formed in the face of the bit that extend from within the cone to the gauge. The channels define a plurality of blades separated by the channels. Each of the plurality of blades has a leading edge with PDC cutters mounted thereon. One or more of the channels are defined by two side walls and a bottom wall and has a length, width and depth. The width or depth remains substantially constant from a first point on its length within the cone to a second point within the shoulder.

A downhole tool string forming a free end portion for performing an operation in a well having a well fluid, the string comprising towards the free end portion; a motor for delivering a rotational speed, a pump connected the motor for circulating the well fluid through a first port and a second port, a gear housing comprising a gear being driven by the pump and delivering a reduced rotational speed, a tool shaft rotatable by the gear at the reduced rotational speed; a reservoir around a section of the tool shaft for collecting dislodged material, and a material dislodging means connected to the tool shaft, wherein the gear housing further comprises a first fluid channel for providing fluid communication between the pump and the first port via the tool shaft being hollow, and a second fluid channel for providing fluid communication between the pump and second port via the reservoir.

A rock bit for blast hole drilling includes a body having a coupling formed at an upper end thereof and a plurality of lower legs, each leg having a top base, an upper shoulder, a mid shirttail, a lower bearing shaft, a leading side, a trailing side and a ported boss, and a plurality of roller cones. Each roller cone is secured to the respective bearing shaft for rotation relative thereto. A row of crushers is mounted around each roller cone. Each leading side and each trailing side are recessed relative to the respective shirttail. Each side has a cuttings channel formed therein. The rock bit further having a nozzle disposed at each ported boss. wherein each nozzle is inclined relative to a longitudinal axis of the rock bit by an outward angle.

A rock bit for blast hole drilling includes a body having a coupling formed at an upper end thereof and a plurality of lower legs, each leg having a top base, an upper shoulder, a mid shirttail, a lower bearing shaft, a leading side, a trailing side and a ported boss, and a plurality of roller cones. Each roller cone is secured to the respective bearing shaft for rotation relative thereto. A row of crushers is mounted around each roller cone. Each leading side and each trailing side are recessed relative to the respective shirttail. Each side has a cuttings channel formed therein. The rock bit further having a nozzle disposed at each ported boss. wherein each nozzle is inclined relative to a longitudinal axis of the rock bit by an outward angle.

A cutting bit includes a bit body and high-pressure body with a high-pressure fluid conduit therethrough. The high-pressure body and bit body are joined together. The high-pressure fluid conduit is configured to convey a fluid at greater than 14.5 ksi, and in some embodiments greater than 40 ksi. The high-pressure fluid conduit may direct the fluid through a nozzle in a fluid jet to weaken material, such as an earth formation. The cutting bit includes at least one roller cone and/or blades with cutting elements thereon to remove the weakened material. A cutting bit includes both high and low-pressure fluid conduits, and high and low-pressure fluid nozzles. The high-pressure nozzles receive fluid flow from a downhole pressure intensifier, and a connection between the bit and the downhole pressure intensifier includes rigid connectors, flexible connectors, or a combination thereof.

A cutting bit includes a bit body and high-pressure body with a high-pressure fluid conduit therethrough. The high-pressure body and bit body are joined together. The high-pressure fluid conduit is configured to convey a fluid at greater than 14.5 ksi, and in some embodiments greater than 40 ksi. The high-pressure fluid conduit may direct the fluid through a nozzle in a fluid jet to weaken material, such as an earth formation. The cutting bit includes at least one roller cone and/or blades with cutting elements thereon to remove the weakened material. A cutting bit includes both high and low-pressure fluid conduits, and high and low-pressure fluid nozzles. The high-pressure nozzles receive fluid flow from a downhole pressure intensifier, and a connection between the bit and the downhole pressure intensifier includes rigid connectors, flexible connectors, or a combination thereof.

A drill bit nozzle includes a nozzle body, a channel in the nozzle body, and a nozzle outlet arranged at an end of the nozzle body and in communication with the channel. The nozzle outlet is a strip-shaped outlet configured to eject a sheet-like jet flow. Since the nozzle outlet of the drill bit nozzle is a strip-shaped outlet, the nozzle outlet is able to eject a sheet-like jet flow. When the drill bit nozzle is applied to a PDC drill bit, the drill bit nozzle can uniformly eject a drilling fluid onto each cutting tooth, which ensures that the cutting teeth in the drill bit may obtain good cooling and chip removal effects, while avoiding excessive concentration of the jet flow from the drill bit nozzle which may erode the cutting teeth, thereby prolonging the service life of the drill bit.

A drill bit nozzle includes a nozzle body, a channel in the nozzle body, and a nozzle outlet arranged at an end of the nozzle body and in communication with the channel. The nozzle outlet is a strip-shaped outlet configured to eject a sheet-like jet flow. Since the nozzle outlet of the drill bit nozzle is a strip-shaped outlet, the nozzle outlet is able to eject a sheet-like jet flow. When the drill bit nozzle is applied to a PDC drill bit, the drill bit nozzle can uniformly eject a drilling fluid onto each cutting tooth, which ensures that the cutting teeth in the drill bit may obtain good cooling and chip removal effects, while avoiding excessive concentration of the jet flow from the drill bit nozzle which may erode the cutting teeth, thereby prolonging the service life of the drill bit.

The present invention relates to a combined crushing super-variable-diameter drill bit for natural gas hydrate exploitation, including a joint, an outer cylinder connected to the joint by thread, a nozzle I mounted in the outer cylinder, a mechanical locking mechanism, a blade telescoping mechanism, an end cap connected to the outer cylinder by thread, a seal ring IV mounted to the end cap, and a nozzle II mounted in the end cap by threaded connection. The present invention achieves integrated operation of conventional drilling and draw-back expanding, which can effectively solve the problems that the existing hydrate drill bit cannot drill a large borehole, cannot mechanically lock an extending position of the blade to stabilize the size of the borehole, and a single crushing method is inefficient.