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 drilling apparatus may alter a direction of travel of a drill bit as it forms a borehole in the earth by furnishing the borehole with a cross-sectional shape that urges the drill bit in a radial direction. Such a cross-sectional shape may comprise two circular arcs, one larger than the apparatus and one smaller. The apparatus may be urged away from the smaller circular arc and into the open space provided by the larger circular arc. Such an apparatus may comprise an axial body and a cutting element extendable in a single radial direction from an exterior of the axial body. Extension of the cutting element may allow it to engage and degrade an inner wall of the borehole. An abrasion-resistant gauge pad protruding from the exterior of the body may ride against the borehole wall and urge the body radially.

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 system for extracting gas from a tectonically-deformed coal seam in-situ by depressurizing a horizontal well cavity is provided. A horizontal well is constructed by a horizontal well drilling and reaming subsystem and adjoins a vertical well to form a U-shaped well, and a horizontal section of the horizontal well is reamed to enlarge hole diameter. A horizontal well hole-collapse cavity-construction depressurization excitation subsystem performs pressure-pulse excitation and stress release on the horizontal well of tectonically-deformed coal bed methane, and hydraulically displaces a coal-liquid-gas mixture such that the mixture is conveyed towards a vertical well section along a depressurizing space. A product lifting subsystem further pulverizes the coal and lifts the mixture towards a wellhead of a vertical well. A gas-liquid-solid separation subsystem separates the coal, liquid and gas. A monitoring and control subsystem detects and controls the operation conditions and the execution processes of technical equipment in real time.

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.

Downhole assemblies comprise at least one sensor configured to sense at least one parameter relating to a downhole condition. The downhole assembly further includes a communications assembly having at least one device for controlling a characteristic of fluid flow through the downhole assembly and a processor in communication with the at least one sensor. The processor is configured to selectively alter the characteristic of fluid flow through the downhole assembly with the at least one device in response to data received from the at least one sensor.

A compression-set straddle packer with fluid pressure-boosted packer set has a two-part multicomponent mandrel and a multicomponent sliding sleeve that reciprocates within a limited range on an upper part of the two-part multicomponent mandrel. A two-part lower packer element compression sleeve in a lower part of the two-part multicomponent mandrel reciprocates on a packer element piston mandrel component and pressure-boosts compression of a lower packer element when high-pressure fluid is pumped into the straddle packer. A bias element constantly resists relative movement between the multicomponent mandrel and the multicomponent sliding sleeve and balances pressure-boost between the lower packer element and an upper packer element supported by the upper part of the two-part multicomponent mandrel.

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.

An earth-boring tool may comprise at least one cavity formed in a face thereof. At least one retractable pad residing in the at least one cavity may be coupled to a piston located at least partially within the at least one cavity. Additionally, a valve may be positioned within the earth-boring tool and configured to regulate flow of an incompressible fluid in contact with the piston through an opening of a reservoir. A cartridge may comprise a barrel wall defining a first bore, and a piston comprising at least one retractable pad positioned at least partially within the first bore. The barrel wall and the piston may define a first reservoir within the first bore, and a valve may be positioned and configured to regulate flow through an opening to the first reservoir. Related methods and devices are also disclosed.

A vibration assembly of a drilling tool for drilling a wellbore penetrating a subterranean formation is disclosed. The downhole drilling tool includes a drill string, a bottomhole assembly and a drill bit. The vibration assembly includes a housing (334a) operatively connectable to the bottomhole assembly, expanders (122) positionable in the housing and radially extendable and retractable thereabout, and a radial vibrator (comprising mandrel (446), enlarger spring (48), cam portion (458) and vibration spring (570) operatively connectable to the expanders to vibrationally move the expanders against the wall of the wellbore whereby movement of the downhole tool is altered during drilling.