A simulation test system for gas extraction from a tectonically-deformed coal seam in-situ by depressurizing a horizontal well cavity. A coal series stratum structure reconstruction and similar material simulation subsystem simulates a tectonically-deformed coal reservoir. A horizontal well drilling and reaming simulation subsystem constructs a U-shaped well in which a horizontal well adjoins a vertical well, and performs a reaming process on a horizontal section thereof. A horizontal well hole-collapse cavity-construction depressurization excitation simulation subsystem performs pressure-pulse excitation and stress release on the horizontal well, and hydraulically displaces a coal-liquid-gas mixture such that the mixture is conveyed towards a vertical well section. A product lifting simulation subsystem further pulverizes the coal and lifts the mixture. A gas-liquid-solid separation simulation subsystem separates the coal, liquid and gas. A monitoring and control subsystem detects and controls the operation and the execution processes of equipment in real time.

A simulation test method for gas extraction from a tectonically-deformed coal seam in-situ by depressurizing a horizontal well cavity. A coal series stratum structure reconstruction and similar material simulation subsystem simulates a tectonically-deformed coal reservoir. A horizontal well drilling and reaming simulation subsystem constructs a U-shaped well in which a horizontal well adjoins a vertical well, and performs a reaming process on a horizontal section thereof. A horizontal well hole-collapse cavity-construction depressurization excitation simulation subsystem performs pressure-pulse excitation and stress release on the horizontal well, and hydraulically displaces a coal-liquid-gas mixture such that the mixture is conveyed towards a vertical well section. A product lifting simulation subsystem further pulverizes the coal and lifts the mixture. A gas-liquid-solid separation simulation subsystem separates the coal, liquid and gas. A monitoring and control subsystem detects and controls the operation and the execution processes of equipment in real time.

An actuation system to control flow of a fluid includes a body including an axial cavity and a valve in fluid communication with the axial cavity, the valve including a closing member moveable into and out of a closed position against the valve seat, and a resistance member. Fluid from the axial cavity can flow through and out of the valve when the closing member is out of the closed position and the closing member is biased into or out of the closed position by a force applied by the resistance member. The closing member is movable out of or into the closed position upon a rotational speed and fluid pressure within the axial cavity being sufficient to overcome the force applied by the resistance member.

Anti-rotation pad assemblies are provided for restraining rotation of a non-rotating housing in geologic drilling system. The anti-rotation pad assemblies include extensible members, which extend from an internal cavity in the anti-rotation pad assemblies and are capable of engaging a wellbore wall. The extensible members may include rollers that are biased radially outwardly to engage the wellbore wall such that the anti-rotation pad assemblies may move axially within the wellbore while restraining the non-rotating housing in a particular rotational orientation. Flow ports are defined in the anti-rotation pad assemblies to encourage mud flow through the internal cavity, and thereby discourage the accumulation and solidification of drilling fluids around the extensible members. The extensible members thus remain free to move under the bias of a biasing mechanism within the internal cavity and can thus effectively maintain the rotational orientation of the non-rotating housing in the wellbore.

The present invention discloses a liquid injection type reamer bit, which comprises a drilling and reaming rod (1), a drilling tool (2) and reaming tools (3). The reamer bit is adopted to perform drilling and reaming operations respectively in a water pressure adjusting manner, has the advantages of simple structure, convenient operation, small volume, light weight, flexible and reliable technology, unified power sources for drilling and reaming, stable reaming, easy recovery of tools, and realization of reaming while drilling, greatly improves the anchoring reliability of anchor bolts, and ensures the safety of workers during underground work.

The present invention discloses a liquid injection type reamer bit, which comprises a drilling and reaming rod (1), a drilling tool (2) and reaming tools (3). The reamer bit is adopted to perform drilling and reaming operations respectively in a water pressure adjusting manner, has the advantages of simple structure, convenient operation, small volume, light weight, flexible and reliable technology, unified power sources for drilling and reaming, stable reaming, easy recovery of tools, and realization of reaming while drilling, greatly improves the anchoring reliability of anchor bolts, and ensures the safety of workers during underground work.

A self-contained module for actuating an element of an earth-boring tool comprises a drive unit configured to be coupled to at least one actuatable element of the earth-boring tool. The drive unit is configured to be disposed at least partially within a compartment of a body of the earth-boring tool. The compartment is radially decentralized within the earth-boring tool. The drive unit includes a drive element configured to be coupled to the at least one actuatable element. The drive unit is configured to move the drive element in a manner moving the at least one actuatable element from a first position to a second position in a direction having a component parallel with a longitudinal axis of the earth-boring tool. The self-contained module is configured to be repeatedly attached to and detached from the earth-boring tool. Such a module may be attached to a tool body carrying extendable elements to form an earth-boring tool for borehole enlargement or stabilization within an enlarged section of the borehole.

A downhole cutting apparatus includes a cutter block. The cutter block includes a formation facing surface with cutting elements coupled thereto. The cutting elements are arranged in rows that may extend at an angle across a width of the formation facing surface. Mud flutes may optionally be located between rows of cutting elements. A gauge portion of the formation facing surface may be adjacent a leading edge having reinforcement members coupled thereto.

A simulation test system for gas extraction from a tectonically-deformed coal seam in-situ by depressurizing a horizontal well cavity. A coal series stratum structure reconstruction and similar material simulation subsystem simulates a tectonically-deformed coal reservoir. A horizontal well drilling and reaming simulation subsystem constructs a U-shaped well in which a horizontal well adjoins a vertical well, and performs a reaming process on a horizontal section thereof. A horizontal well hole-collapse cavity-construction depressurization excitation simulation subsystem performs pressure-pulse excitation and stress release on the horizontal well, and hydraulically displaces a coal-liquid-gas mixture such that the mixture is conveyed towards a vertical well section. A product lifting simulation subsystem further pulverizes the coal and lifts the mixture. A gas-liquid-solid separation simulation subsystem separates the coal, liquid and gas. A monitoring and control subsystem detects and controls the operation and the execution processes of equipment in real time.

A downhole cutting tool which may be a reamer or a mill has a rotary tool body with at least one block which carries hard-faced cutters and projects or is extensible from the tool body. A radially outward facing part of the cutter block defines a channel for fluid flow which extends generally axially along the cutter block. The channel is configured such that at least the rotationally trailing edge of the channel extends along the block in one or more directions which are inclined relative to the tool axis. This reduces or avoids the amount of channel edge parallel to the tool axis and thereby mitigates whirling and/or or vibration.