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.

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.

A milling tool for use in a cased wellbore. The milling tool has a housing having a plurality of pockets formed therein. A blade is installed within each pocket and is movable between open and closed positions. The blade projects from the pocket when in an open position. Rotation of the housing causes the blades to move to an open position. The blades remain in a closed position when the housing is not rotating.

A drilling machine for a wellbore is provided. The drilling machine may include a dynamic lateral pad that is movable between an extended and retracted position. In the extended position, the pad moves the drill bit in a direction for drilling. The drilling machine may include a dynamic lateral cutter that is movable between an extended and retracted position. In at least the extended position, the cutter engages the wellbore and removes formation. The drilling machine may include a monolithic or integral drill bit/drive shaft to reduce the distance between a positive displacement motor and a distal end of the monolithic or integral drill bit/drive shaft. The drilling machine may include separate cutting structures that have different rotational speeds and can further utilize the integral drill bit/drift shaft and/or a bent housing that generates an off-axis rotation which helps optimize the formation removal in the center area of the wellbore.

A drilling machine for a wellbore is provided. The drilling machine may include a dynamic lateral pad that is movable between an extended and retracted position. In the extended position, the pad moves the drill bit in a direction for drilling. The drilling machine may include a dynamic lateral cutter that is movable between an extended and retracted position. In at least the extended position, the cutter engages the wellbore and removes formation. The drilling machine may include a monolithic or integral drill bit/drive shaft to reduce the distance between a positive displacement motor and a distal end of the monolithic or integral drill bit/drive shaft. The drilling machine may include separate cutting structures that have different rotational speeds and can further utilize the integral drill bit/drift shaft and/or a bent housing that generates an off-axis rotation which helps optimize the formation removal in the center area of the wellbore.

A rotary cutting tool for use in a wellbore has an instrumented cutter fitted into a cavity in the tool body. The instrumented cutter body has an outer end portion exposed at the open end of a cavity and is connected to the tool body through at least one connecting section having a smaller cross-section and greater compliance than the outer end portion. The outer end portion and the connecting section are slightly movable within the cavity but the cavity surrounds at least part of the outer end portion sufficiently closely to limit transverse movement to elastic strain of the compliant connecting portion. One or more sensors, which may be strain gauges, are used to measure force on the outer end portion in a plurality of directions transverse to the cavity and causing elastic strain of the at least one connecting section.

A rotary cutting tool for use in a wellbore has an instrumented cutter fitted into a cavity in the tool body. The instrumented cutter body has an outer end portion exposed at the open end of a cavity and is connected to the tool body through at least one connecting section having a smaller cross-section and greater compliance than the outer end portion. The outer end portion and the connecting section are slightly movable within the cavity but the cavity surrounds at least part of the outer end portion sufficiently closely to limit transverse movement to elastic strain of the compliant connecting portion. One or more sensors, which may be strain gauges, are used to measure force on the outer end portion in a plurality of directions transverse to the cavity and causing elastic strain of the at least one connecting section.

A well tool for generating a notch in an open-hole wellbore, includes a tool body having a housing defining at least one slot and an interior volume. The tool body includes a cutting device disposed in the interior volume, configured to form a notch in a formation. The cutting device includes a shaft disposed in the interior volume of the housing having a first portion with a first exterior threads that extend around the first portion in a first direction, and a second portion having second exterior threads that extend around the second portion in a second direction opposite the first direction. The cutting device includes multiple blades configured to extend radially outward toward the formation through the slot or inward away from the formation and having a first blade extending from the first portion of the shaft and a second blade extending from a second portion of the shaft.

A well tool for generating a notch in an open-hole wellbore, includes a tool body having a housing defining at least one slot and an interior volume. The tool body includes a cutting device disposed in the interior volume, configured to form a notch in a formation. The cutting device includes a shaft disposed in the interior volume of the housing having a first portion with a first exterior threads that extend around the first portion in a first direction, and a second portion having second exterior threads that extend around the second portion in a second direction opposite the first direction. The cutting device includes multiple blades configured to extend radially outward toward the formation through the slot or inward away from the formation and having a first blade extending from the first portion of the shaft and a second blade extending from a second portion of the shaft.

A flow rate control system includes a housing and a valve assembly slidingly disposed within a housing inner bore. The housing includes bypass openings. The valve assembly includes a valve and an orifice disposed in a valve inner bore. The valve includes a plurality of valve bypass bores extending axially through a valve collar. The valve assembly slides between closed and fully open positions. A spring biases the valve assembly toward the closed position in which the valve closes the housing bypass openings. In the open position, a bypass fluid path is formed including the valve bypass bores and the housing bypass openings. The valve assembly is flow rate controlled in the closed position and pressure controlled in the open position. The valve assembly may slide within a sleeve assembly including sleeve bypass openings, which connect the valve bypass bores and housing bypass openings in the bypass fluid path.