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.

The present disclosure relates to an underreamer. In one aspect, the underreamer comprises a body, the body comprising at least one pocket therein, the underreamer further comprising at least one cutter secured with respect to the body, at least one actuating mechanism for moving the cutter between a retracted position in the pocket, and an extended position in which only the cutter projects from the body. In one aspect, the or each actuating mechanism comprises a piston for driving extension of the cutter, and a linkage to a cutter arm with respect to which the cutter is mounted, and a return spring for biasing the cutter to the retracted position.

Rotatable elements for use with earth-boring tools include a movable element and a stationary element. The movable element and stationary element include an index positioning feature that is configured to rotate the movable element as the movable element moves between a first axial position and a second axial position.

Disclosed is an internal reamer for anchor shaft hole for mining, comprising a reaming cutter, a sleeve, a push-pull rod, a drilling machine connecting shaft and a manual hydraulic jack, wherein the push-pull rod is disposed in the sleeve coaxially, a rear end of the reaming cutter is connected to a front end of the push-pull rod, a rear end of the sleeve is connected with a guiding cylinder having an inner diameter larger than the sleeve, a rear end of the guiding cylinder is connected with a mounting cylinder coaxially, the manual hydraulic jack is installed in the mounting cylinder, a rear end of the push-pull rod is fixedly connected with a piston plate which is slidingly and sealingly matched with an inner wall of the guiding cylinder, and the front end of the drilling machine connecting shaft is fixedly connected with the rear end of the mounting cylinder.

Disclosed is an internal reamer for anchor shaft hole for mining, comprising a reaming cutter, a sleeve, a push-pull rod, a drilling machine connecting shaft and a manual hydraulic jack, wherein the push-pull rod is disposed in the sleeve coaxially, a rear end of the reaming cutter is connected to a front end of the push-pull rod, a rear end of the sleeve is connected with a guiding cylinder having an inner diameter larger than the sleeve, a rear end of the guiding cylinder is connected with a mounting cylinder coaxially, the manual hydraulic jack is installed in the mounting cylinder, a rear end of the push-pull rod is fixedly connected with a piston plate which is slidingly and sealingly matched with an inner wall of the guiding cylinder, and the front end of the drilling machine connecting shaft is fixedly connected with the rear end of the mounting cylinder.

The multifunction wellbore conditioning tool (100, 200, 300) is installed in the bottom hole assembly of a drill string and performs the functions of a cutting tool, keyseat wiper, roller reamer, keyseat wiper, and stabilizer during drilling operations, precluding the need for multiple different tools in the drill string. The tool (100, 200, 300) has a working sleeve (114, 214, 314) captured concentrically on the driveshaft (102, 202, 302) between opposed spring sets (134, 136; 234, 236; 334, 336). The sleeve (114, 214, 314) remains rotationally stationary about the rotating driveshaft (102, 202, 302) when in its central or neutral position on the driveshaft (102, 202, 302). When the sleeve (114, 214, 314) shifts axially on the driveshaft (102, 202, 302) it engages a clutch mechanism that allows it to rotate with the driveshaft (102, 202, 302) so that the rotating working sleeve (114, 214, 314) conditions the borehole.

Drilling dysfunction during simultaneous down-hole drilling and reaming is reduced by obtaining an indication of force on cutters of a reamer, determining whether or not the indication indicates an excessive force, and upon determining that the indication indicates an excessive force, extending drag elements from the bottom hole assembly to contact a wall of the well bore and reduce the force on the cutters of the reamer. The indication of force on the cutters can be obtained by sensing the weight on the drill bit, and the determination can be done by comparing the indicated weight on the drill bit to a first threshold and a second threshold.

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.

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.

A modular reamer shoe for connection to an end of a tubular structure, such as a casing or liner, for deployment in a wellbore includes a body configured for connection to the tubular structure (casing or liner). The body includes a first section and an adjacent second section. The first section is connected to the second section such that torque can be transmitted between the first section and the second section. The first section defines a starter reamer defined by a plurality of first cutting elements and second cutting elements spaced from the first cutting elements. The reamer shoe has a plurality of actuatable blades disposed within the second area of the first section. The plurality of blades moves between extended positions and retracted positions. A nose is connected to the first section of the body. The second section is actuatable and can move in an axial direction so as to move the body, including the nose, in forward/rearward directions.