Abstract: A reverse-circulation drilling assembly having an overshot subassembly and a head subassembly. In the event retrieval of the drilling assembly by reverse-circulation fails, the drilling assembly can be retrieved using a secondary overshot.

Abstract: A horizontal drilling machine with an in-situ detection device, including a support frame, an armored cable, a steel pipe-straightening mechanism, a steel pipe-feeding mechanism, a motor, a power head, a drill pipe, a rotating chuck, a damper, a non-core drilling tool, the in-situ detection device, a fishing device and a thrust cylinder. The steel pipe-straightening mechanism, the steel pipe-feeding mechanism, the rotating chuck and the damper are sequentially fixed on the support frame from left to right. One end of the thrust cylinder is hinged with the support frame, and the other end is connected to the power head. The active drill pipe of the power head is connected to the drill pipe. An end of the armored cable is connected to the fishing device in the drill pipe, and the fishing head of the fishing device is connected to the spearhead of the non-core drilling tool.

Abstract: A horizontal drilling machine with an impact device, including a support frame, an armored cable, a cable-straightening mechanism, a cable-feeding mechanism, a power head, a drill pipe, a rotating chuck, a damper, a fishing device with the impact device, a core tube and a thrust cylinder. One end of the thrust cylinder is hinged with the support frame, and the other end of the thrust cylinder is connected to the power head. The power head is arranged on a slid rail of the support frame. An active drill pipe of the power head is connected to the drill pipe. An end of the armored cable is connected to a control system, and the other end is connected to the fishing device in the drill pipe. A fishing head of the fishing device is connected to a spearhead of the core tube.

Abstract: An overshot assembly for operative coupling to a wireline and a head assembly within a drilling system. The overshot assembly has a proximal body portion, a distal body portion, and a spindle received within the distal body portion. The distal body portion is moveable axially relative to the spindle to effect movement of a latching assembly about and between a deployed position in which the latching assembly extends radially outwardly from the distal body portion and a retracted position in which the latching assembly is received within the distal body portion.

Abstract: A core drilling apparatus and a method for converting between a core drilling assembly and a full-diameter drilling assembly by means of a lifting device and a coring drill head with closure elements and integrated cutting implements. The lifting device comprises a release mechanism that when activated, releases forces acting on the lifting device, such that when the lifting device is in an upper position when activated, the lifting device lowers an inner tubing thereby pushing the closure elements of the drill head in an open position, and when the lifting device is in a lower position when activated, the lifting device lifts the inner tubing from the closure elements such that the closure elements is in a closed or partly closed position.

Abstract: A downhole completion includes a production casing and a sliding sleeve assembly connected as part of the production casing. The completion includes a tubular part and a tubular sleeve.

Abstract: An overshot assembly for operative coupling to a wireline and a head assembly within a drilling system. The overshot assembly has at least one latch member that securely engages the inner surface of the head assembly without the use of a spearhead.

Abstract: The downhole flow control means or downhole blowout preventor (downhole BOP) of the present invention is adapted for use during reverse circulation drilling with both concentric drill pipe and concentric coiled tubing. The downhole BOP comprises an inner tube member having an inner passage therethrough and an outer casing forming an annular passage between the inner tube member and the outer casing. The inner passage and the annular passage of the downhole BOP is in fluid communication with the inner passage and annular passage, respectively, of the concentric drill pipe or concentric coiled tubing. The downhole BOP further comprises two valve means, preferably a check valve and a ball valve, for closing off the annular passage and the inner passage of the downhole BOP, respectively. In a preferred embodiment, the downhole BOP further comprises an electric actuator for opening and closing the ball valve.

Abstract: A riser pipe containment valve attached to the drill string tool that uses the wells' intense pressure to cap and control flow when lowered down the riser and attached to its internal wall. Oil/gas sealing and stoppage flow through the valve are controlled by stop flow plug movement. The valve attached then to the riser pipe wall is locked to that surface with pressure indented balls forced into wall indented cavities locking valve to riser in multiple engagement points. When the valve is installed as a riser pipe insert, and used as a by-pass stop flow pipe, without retention attachments, it continues to function as an oil/gas stop flow plug system, and electronic sensors in the valve are utilized to monitor flow and sealing conditions relative to high pressure and convey data to the drill string tool and its electronic system display.

Abstract: Equipment and methods which may be used in conjunction with an underbalanced well completion. In a described embodiment, a valve for use in a subterranean well in conjunction with a tool conveyed through the valve in a container is provided. The valve includes a passage formed longitudinally through the valve, a closure assembly which selectively permits and prevents flow through the passage, and an engagement device which engages the container as the tool is conveyed through the passage. The closure assembly permits flow through the passage when the container is conveyed into the passage, and the closure assembly prevents flow through the passage when the container is removed from the passage. Engagement between the container and the engagement device separates the tool from the container.

Abstract: The drilling apparatus includes a safety sub mountable to the drill string outer end to retain the combination of an overshot assembly and an overshot adaptor extending within the drill string outer end during a drilling operation and preventing the drilling tool moving out of the drill string until the sub is removed. The overshot assembly has a fluid seal between the overshot tube and the drill string and a fluid bypass channel with/a valve for blocking axial outward flow through the channel when the overshot adaptor is separated from the overshot assembly and when connected thereto, retaining the valve in an open condition. When the overshot adaptor is removed from the overshot assembly, the overshot assembly is fluidly propellable to the bit end. A disconnect tool facilitates the removal of the adaptor from the sub.

Abstract: A roller cone drill bit is disclosed which includes a bit body having at least one leg depending from the bit body. The leg has a journal formed on it at a lower end. The bit body includes an air channel extending at least from an interior of the bit body to the seal area of the journal. A roller cone is sealingly, rotatably mounted on the journal. The cone has a plurality of cutting elements disposed on it. The bit includes a backflow valve disposed in the bit body, so that an intake end of the air channel is disposed upstream of the backflow valve. In one embodiment, the backflow valve is disposed in a connection end of the bit body, and the air channel includes a flow tube extending from the air passage in the bit body to the backflow valve so that its intake end is upstream of the backflow valve.

Abstract: A rock-crushing rotary drill bit includes a body having a rock-crushing roller rotatably mounted thereon by bearings. The body includes a first flushing channel for conducting flushing fluid to flush the bearings, and a second flushing channel for discharging flushing medium outside of the bit body to flush away cuttings. The second flushing channel terminates in a discharge recess which defines a linear center axis. A nozzle is disposed at a downstream end of the discharge recess, and a valve element is disposed at an upstream end of the discharge recess. The valve element is spring-biased for closing the discharge recess, the valve element being openable against the spring bias in response to a sufficient pressure build-up of flushing medium within the second flushing channel. The valve element includes a guide structure for guiding the valve element for linear movement along the center axis of the discharge recess.

Abstract: An extension drilling system for use with a semiautomatic drilling rig. The drilling system includes a plurality of extension rods constituting a drill rod string and having cooperating male and female threaded couplings therebetween, and being right-hand rope threaded couplings. A reversible drive chuck of a drilling rig drives (either directly, or via an adaptor), the outside of the female threaded end of an associated extension rod. A gripper grips one of the extension rods to hold the drill rod string stationary when the chuck is driven in reverse. The gripper is located such that only one threaded coupling is disposed between the chuck and grippers and to ensure that when the chuck is rotated in reverse, only the desired coupling is uncoupled. The drill rods have axial passages therethrough in communication with each other and through which flushing fluid is delivered to an associated drill bit and a non-return valve is incorporated in the passage through at least one of the drill rods.

Abstract: An axial bore is defined throughout the hydraulic lift inner barrel. This axial bore is communicated with the interior of the inner tube thereby allowing the interior of the inner tube to be flushed prior to initiation of the coring operation. When the coring operation is begun, flow of drilling fluid to the interior of the inner tube is prevented by allowing a ball dropped within the drill string to seat within a plug through which the communicating axial bore is defined. Once the flow of drilling fluid to the interior of the inner tube is stopped, the coring operation can begin. After the coring operation is completed, a second ball is dropped and allowed to seat within an inner mandrel through which the axial bore of the coring tool is also defined. Once the axial bore of the inner mandrel is closed, drilling fluid is forced into an expansion chamber within a telescopic piston disposed circumferentially outside of the inner mandrel. The piston is connected to the inner tube.

Abstract: A plurality of valve structures are incorporated in a drill pipe string for drilling a well into the earth utilizing air as the drilling fluid. A first valve is located in the drill pipe string just above the drilling bit, and an additional valve or valves are located in upwardly spaced relation within the drill collar string. Each of the valves has a valve member held in a position allowing the flow of air through the valve by a fusible support, and when the support melts, the valve member will shift to a position closing the valve. The valve just above the bit is combined with a float valve to prevent the upward flow of fluid into the drill string, while the valve or valves spaced upwardly in the drill collar string are full opening valves which allow the running of instruments through the drill string to selected locations above the bit. The additional upwardly spaced valve or valves include a flap held in a position to one side of the bore through the valve body by a fusible retainer.