Abstract: An expandable reaming tool including at least two reamer pads connected to a tool body. The reamer pads are adapted to be displaced between a retracted position and an expanded position. At least one spiral blade is formed on at least one reamer pad. A plurality of cutting elements are disposed on the at least one spiral blade.

Abstract: An expandable reamer apparatus and methods for reaming a borehole, wherein a laterally movable blade carried by a tubular body may be selectively positioned at an inward position and an expanded position. The movable blade, held inwardly by blade-biasing elements, may be forced outwardly by drilling fluid selectively allowed to communicate therewith by way of an actuation sleeve disposed within the tubular body. Alternatively, a separation element may transmit force or pressure from the drilling fluid to the movable blade. Further, a chamber in communication with the movable blade may be pressurized by way of a downhole turbine or pump. A ridged seal wiper, compensator, movable bearing pad, fixed bearing pad preceding the movable blade, or an adjustable spacer element to alter expanded blade position may be included within the expandable reamer. In addition, a drilling fluid pressure response indicating an operational characteristic of the expandable reamer may be generated.

Abstract: The present invention generally relates to an apparatus and method of forming a wellbore. In one aspect, an expandable bit for use in a wellbore is provided. The expandable bit includes a body and a blade assembly disposed on the body. The blade assembly is movable between a closed position whereby the expandable bit has a smaller outer diameter and an open position whereby the expandable bit has a larger outer diameter. The expandable bit further includes a release assembly for providing a secondary means to move the blade assembly from the open position to the closed position. In another aspect, a method of forming a wellbore is provided. In yet another aspect, an expandable apparatus for use in forming a wellbore is provided.

Abstract: The present invention provides a down-hole tool (7) with at least one radially outwardly deployable tool element (33) for use in a bottom hole assembly (1) provided with a pressurised down-hole motor drive fluid supply (50). The tool (7) comprises a body (9) having at least one tool element (33) having a mounting, proximal, end portion (32) pivotally mounted (31) on said body, and a working, distal, end portion (34) displaceable between a stowed, radially inward, position and a deployed, radially outward, position. The proximal end portion (32) is provided with an engagement portion (29, 30) formed and arranged for driven engagement with a drive member (23) axially displaceable by a piston and cylinder device (19, 20). In use of the tool (7), axial displacement of the drive member (23) causes said proximal end portion (32) to rotate and displace said tool element working end portion (34) between said stowed and deployed positions thereof.

Abstract: A downhole tool that functions as an underreamer, or alternatively, as a stabilizer in an underreamed borehole. The tool includes one or more moveable arms disposed within a body having a flowbore therethrough in fluid communication with the wellbore annulus. The tool alternates between collapsed and expanded positions in response to differential fluid pressure between the flowbore and the wellbore annulus. In one embodiment, the tool moves automatically in response to differential pressure. In a second embodiment, the tool must be selectively actuated before it is moveable. When the tool expands, the arms are preferably translated axially upwardly, while simultaneously being extended radially outwardly from the body. The expanded tool diameter is adjustable at the surface without changing components. The arms may include borehole engaging pads that comprise cutting structures or wear structures or both, depending upon the function of the tool.

Abstract: Bore hole underreamer in a terrestrial formation, intended in particular for oil drilling and especially to be fixed in the vicinity of a drill head, the underreamer having a hollow body (1), with a longitudinal axis (3), which has an external wall (5), at least two cylindrical bores (7) provided through the external wall (5) and whose axes (9) are transverse to the longitudinal axis (3), the bores being distributed over the circumference of the hollow body, and in each of the bores, a cylindrical widening arm (11) which has a cutting end (13), disposed on the outside of the body and provided with blades (15) for widening the hole, which is arranged in the bore like a hydraulic piston, so as to be able to slide therein between an active position in which this cutting end (13) is distant from the body, and an inactive position, and whose other end, inside the body, is intended to receive from a fluid a pressure capable of pushing the said arm into its active position, the underreamer having a locking member (2

Abstract: An underreamer for forming a cavity from within a well bore includes a housing adapted to be disposed within the well bore. The underreamer includes an actuator partially slidably positioned in the housing. The actuator comprises a first portion and a second portion. A cross-sectional area of the second portion is larger than a cross-sectional area of the first portion. The underreamer includes at least one cutter set, wherein each cutter set has a first end and a second end. The first end of each cutter set is pivotally coupled to the housing. The second end of each cutter set is pivotally coupled to a connector. An axial force applied to the actuator is operable to slide the actuator relative to the housing causing the second portion of the actuator to contact each cutter set and extend each cutter set radially outward relative to the housing from a retracted position to a first position. The actuator may also include a stop member proximate an end of the actuator.

Abstract: A method and apparatus for milling a section of casing in an upward direction, utilizing a downhole hydraulic thrusting mechanism for pulling a section mill upwardly. A downhole motor and torque anchor can be used to rotate the section mill, or the mill can be rotated by a work string. A stabilizer above the section mill can be used to stabilize the mill relative to the casing being milled. A spiral auger below the section mill can be used to move the cuttings downwardly.

Abstract: An underreamer (5) is formed from a tubular body (10) having a longitudinal bore therethrough, and providing an integral piston actuator (20) responsive to hydraulic pressure to move cutters (40) into engagement with the well bore and springs (60) to resist premature engagement of the cutter arms (40) and to return the cutters (40) to the body upon conclusion of the underreaming job. Skewed longitudinal grooves (45) are formed in the tubular body thereby permitting the flowpath through the underreamer to provide substantially the same inner diameter throughout the tool (5).

Abstract: A drilling apparatus for earth boring operations is of the type having cutter blades mounted on a support body at the lower end of a drill string and includes a novel arrangement of fluid bore sections for delivering fluid under pressure into fluid discharge passages in each of the blades and a bifurcated pivotal mounting portion on the body which enables the bore sections to supply fluid to the cutter blades through a ball joint on the pivotal axis. Modified forms of invention are specifically designed for cutter blades which are intended to perform reaming operations but include the fluid delivery system as well as an extended delivery system for delivering fluid under pressure to other tools in the drill string.

Abstract: A downhole tool (10) for mounting on a drill string comprises: a mandrel (16); a body (18) axially movably mounted on the mandrel; and radially extendable members, such as stabiliser blades or cutters (30), mounted in the body and being operatively associated with the mandrel such that relative axial movement of the mandrel and body induces radial movement of the members. Application of axial tension to the tool produces axial movement of the body relative to the mandrel, tending to retract the members from an extended configuration. The mandrel may be arranged to draw the members inwardly to permit positive retraction of the members from an extended configuration. Further, the body may define a channel (32) and the mandrel and the members include an arrangement (38, 39, 40, 42) for maintaining a desired orientation of the members relative to the body channel.

Abstract: A downhole tool is disclosed that functions as an underreamer, or alternatively, as a stabilizer in an underreamed borehole. An embodiment of the tool includes one or more moveable arms disposed within a body having a flowbore therethrough in fluid communication with the wellbore annulus. The tool alternates between collapsed and expanded positions in response to differential fluid pressure between the flowbore and the wellbore annulus. In one embodiment, the tool moves automatically in response to differential pressure. In a second embodiment, the tool must be selectively actuated before it is moveable. When the tool expands, the arms are preferably translated axially upwardly, while simultaneously being extended radially outwardly from the body. The expanded tool diameter is adjustable at the surface without changing components. The arms may include borehole engaging pads that comprise cutting structures or wear structures or both, depending upon the function of the tool.

Abstract: An underreamer for forming a cavity within a well bore includes a housing rotatably disposed within the well bore. The underreamer also includes a plurality of cutting blades pivotally coupled to the housing. The underreamer further includes a piston slidably disposed within the housing and adapted to engage the cutting blades. The piston is operable to receive a downwardly disposed force operable slide the piston relative to the housing. The sliding movement of the piston extends the cutting blades outwardly from a retracted position relative to the housing. The underreamer also includes a passage disposed within the piston and operable to communicate a fluid received via an annulus of the housing to the cutting blades.

Abstract: An expandable drill bit (10) comprises a body (14) for mounting on a support string and two roller cutters (12, 13) mounted on the body (14). The cutters (12, 13) are movable between a smaller diameter first configuration and a larger diameter second configuration. In one embodiment the bit (10) is adapted to drill with the cutters (12, 13) in both the first and second configurations.

Abstract: A drilling assembly and an eccentric, adjustable diameter reamer are disclosed. The reamer includes cutter elements mounted on at least a first fixed blade for reaming a previously-formed borehole or for forming a borehole of increased diameter beneath an existing cased borehole. The method and apparatus provide for stabilizing the drilling assembly so that the reamer may be used in back reaming the hole. Retainer means, such as shear pins or spring-biased reciprocating latch members, are provided to prevent premature extension of the reamer's moveable members, including blades and pistons. The shear pins are preferably accessible from the outer surface of the reamer housing so as to expedite field replacement of the shear pins without requiring disassembly of the reamer. The spring-biased latching members repeatedly latch and unlatch so that field replacement is not required, and so that the movable members may be extended and contracted multiple times while the reamer is downhole.

Abstract: A method and apparatus for installing a pile or load-bearing element into soft ground, wherein a non-percussive force, rather than a percussive force such as that applied by a hammer or a jack, is applied to the top of a hole-forming tool or pile (1) so as to push the hole-forming tool or pile (1) in a substantially continuous motion to a first depth into the ground, and wherein the hole-forming tool or pile (1) is then pushed in a non-percussive manner to a second depth while being simultaneously rotated. A cast-in-situ pile is formed in soft ground by pushing a hole-forming tool (1) provided with fins (3) at its base into the ground. Once the required level has been reached, the hole-forming tool (1) is rotated and concrete or grout is pumped through the body of the hole-forming tool so as concomitantly to help displace and replace the soil swept away by the fins (3).

Abstract: An apparatus for shaping boreholes used in seismic operations. A drill body is attached to a drill bit and is movable in axial and rotational directions. Selective operation of the drill body causes a moveable sleeve to operate a reaming bit to extend through a drill body port and into contact with the borehole wall. A cover seals the portion of the port not covered by the reaming bit to prevent loss of a transport fluid within the drill body and to prevent drill cuttings from entering the drill body interior. The cover can be integrated within the movable sleeve or can comprise a separate component. The force exerted by the drill body against the drill bit can be proportional to the force exerted by the reaming bit against the borehole wall. The reaming bit can be operated separately or simultaneously with operation of the drill bit, and can be retracted and reset to perform another shaping operation at a different position within the borehole.

Abstract: An intelligent multi-functional hydraulic expanding apparatus includes a hydraulic expanding head, an automatic control hydraulic center, and a depth measuring system. The expanding head includes a hydraulic positioning device, an automatic hydraulic revolving device, a bi-directional cylinder uni-directional pulling type cylinder, and expanding arms that are rigidly connected. As the expanding apparatus adopts steel rope connection, the automatic reviving device performs transfer of torque, multi-arm expanding arms are installed in the same circular cross-section with displacement sensors, computer, and depth measuring system, the present invention provides a solution to the drag problem, increasing efficiency of construction of concrete piles for various foundations of buildings, bridges and obtain pressure angles and depth values so as to improve quality of the construction project.

Abstract: A tubular actuator component (20) for use in a drill-string is disclosed and which comprises a main tubular outer body (6) within which a clutch mechanism, mandrel (2), and pad mandrel (7) are located. The clutch mechanism comprises a lower stationay clutch component (4), secured upper clutch component (12) and an intermediate clutch component (1) such that application of fluid aetuating pressure to the interior of the tubular component axially displaces intermediate clutch member (1) between positions of co-operative engagement with one or the other of the lower stationary clutch component (4) and the secured upper clutch component (12).

Abstract: A downhole unit for use in subsurface boreholes, for example a bias unit for imparting a lateral bias to the drill bit to control the direction of drilling, includes a main body and a number of pads pivotally mounted on the main body for engagement with the walls of the borehole. A thrust member is disposed inwardly of each pivotal pad and is movable along a guide passage in the main body to transmit movement to the pad. Each thrust member is movable by hydraulic pressure and a fluid-tight sliding seal is provided between the thrust member and its guide passage. The outer surface of each thrust member or the inner surface of the guide passage, or both, is in the form of a portion of a toroid centred on the pivot axis of the respective pad so as to minimise lateral movement of the seal as the thrust member moves along the passage. This also allows relative displacement between the thrust member and pad to be avoided, so that the thrust member can be integral with the pad or rigidly connected to it.

Abstract: A 2-stage underreamer for use in a subterranean wellbore includes a unitary body having upper and lower blades mounted in slots formed perpendicular to each other in the body. Separate upper and lower piston assemblies are provided for driving the blades respectively from a storage configuration in which they are located substantially completely within the slots to a use position. The blades each include a steel arm having mounted thereon a base of tungsten nickel cobalt matrix in which diamond and/or tungsten carbide inserts are provided. A signal is given to the surface that the blades are in their extended position by changing the mud.

Abstract: The present invention relates to water-soluble, particularly ternary, preferably ionic, cellulose mixed ethers, more particularly to anionic water-soluble cellulose mixed ethers, as additives for drilling fluid applications.

Abstract: A wellbore is formed in the earth with an elongated, non-rotating tubular drillstem which may consist of a well casing or liner and including an expendable sub and reamer bit part connected to the lower distal end of the drillstem. A retrievable drilling fluid operated motor and drive member assembly are disposed in the drillstem. The motor and drive member include pressure fluid responsive mechanism for engagement with and disengagement from the reamer bit part to rotatably drive the reamer bit part and a central bit part connected to the drive member without rotating the casing type drillstem. The motor, drive member and central bit part may be retracted from the drillstem upon completion of drilling operations without retrieving the expendable reamer bit part.

Abstract: A downhole rotary cutting tool having an elongated cylindrical body with radially expanded cutting blades that are controlled by application of selected fluid as controlled from a surface source. The cutting blades have a combined abrading/jetting capability as hardened cutting surfaces are disposed at critical points of each blade and each cutting blade is ported to provide lateral jet emissions for entry into the surrounding earth medium.

Abstract: An under-reaming tool for use in preferably horizontal and extended reach bore holes includes a succession of stabilizers, under-reamers and expandable stabilizers. A common drilling mud activator is provided for the expandable elements of under-reamers and expandable stabilizers. A preferred under-reaming device comprises a main body with a number of guiding surfaces distributed over the circumference thereof which have a pitch increasing radially in an axial direction and with a ring collar formed as a piston in a surrounding cylinder housing having a small and a large radial annular surface, and having reaming pads/wings and/or stabilizer pads/wings in sliding contact with a respective guiding surface, the pads being taken up in ports in a jacket surrounding the main body, in such a way that the pads can only be moved radially relative to the jacket, the jacket being attached to or formed as a part of the cylinder housing.

Abstract: Wellbores are formed in the earth with elongated, tubular drillstems which include retrievable bit assemblies. The retrievable bit assembly includes a body having locking dogs engageable with cooperating recesses formed in a sub at the bottom of the drillstem. The bit assembly includes radially extendable and retractable arms with cutters thereon for forming the wellbore to a diameter greater than the drillstem, but whereby the arms may be retracted to withdraw the bit assembly through the drillstem with wireline retrieval apparatus or the like. The wellbore may be drilled with a tubular drillstem comprising wellbore casing with a bit connected to the lower end of the drillstem and retrievable through the drillstem by the wireline retrieval apparatus whereby the casing may be left in the wellbore upon completion of drilling operations.

Abstract: A process and apparatus for forming a hole within an unconsolidated hydrocarbonaceous fluid-bearing formation, installing a slotted liner and gravel packing the liner in a single trip into the formation. The apparatus includes a drill bit for drilling a pilot hole; a housing mounted above the pilot hole drill bit; means for enlarging a pilot hole, the pilot hole -enlarging means pivotally mounted within the housing and capable of pivoting between a retracted position and an expanded position for enlarging a pilot hole to a diameter larger than the pilot hole and sufficient for gravel packing; a slotted liner having a first end and a second end, the first end joined to the apparatus above the housing; and a drive assembly joined to the second end of the slotted liner.

Abstract: A process for installing a gravel pack within an unconsolidated hydrocarbonaceous fluid-bearing formation.

Abstract: The invention consists of the shape and design of plural pairs of cutter blades for use in rotary tubing tools which cutter blades have specialized shapes and cutting surfaces for performing certain specific downhole cutting operations adjacent a tubing string.

Abstract: A downhole cutting tool for use down along a tubing string consisting of an elongate body member having central cavity and transverse slotway and receiving drilling fluid axially therethrough. An expandable double blade is pivotally housed in the slotway while fluid actuated pistons above and below are effective to expand the blades outboard on each side and to brace the blades in operative position as the body member is rotated and the blades abrade or cut the adjacent material.

Abstract: Wellbores are formed in the earth with elongated, tubular drillstems which include retrievable bit and drive motor assemblies. The retrievable bit assembly includes a body having locking dogs engageable with cooperating recesses formed in a sub at the bottom of the drillstem. The bit assembly includes radially extendable and retractable arms with cutters thereon for forming the wellbore to a diameter greater than the drillstem, but whereby the arms may be retracted to withdraw the bit assembly through the drillstem with wireline retrieval apparatus or the like. The wellbore may be drilled with a tubular drillstem comprising wellbore casing with a retrievable bit and motor assembly connected to the lower end of the drillstem and retrievable through the drillstem by the wireline retrieval apparatus whereby the casing may be left in the wellbore upon completion of drilling operations.

Abstract: The well reamer comprises a sub for attaching it to the drive means, a hollow housing with a central channel and radial openings in its side wall, projectable rolling cutters with shanks, mounted in the radial openings of the housing, and a mechanism for projecting the rolling cutters, including a piston and a member for locking the rolling cutters in their operating positions. The annular piston is connected with the housing for joint rotation therewith, and is regidly connected with the sub. The wall of the piston has radial passages made therein, establishing communication between its central channel and so annular space defined between the walls of the piston and of the housing. The member for locking the rolling cutters is accommodated with a clearance in the central channels of the piston and of the housing, and has an annular shoulder. The central channel of the piston defines a seat for engagement with the annular shoulder of the locking member.

Abstract: A dual blade cutter head for a rotary cutting tool which consists of two identical blades disposed in opposed position, each blade having an outer arcuate edge movable into cutting contact and having suitable hard facing affixed to the arcuate edge oriented for right-turn cutting rotation. In one form the hardface is an arcuate inlay block faced with thermally stable polycrystalline diamond.

Abstract: An expandable drill bit for cleaning solidified cement from a well casing used in oil drilling operations. The bit has an initial diameter which allows it to be passed through a permanent restriction in a well casing and thereafter expanded to clean out the casing below the restriction. The bit has three uniformly spaced cutting elements which may be fully retracted within the diameter of the cylindrical outline of the body of the bit and are located at the forwardmost end in a strengthened portion of the body. The cutting elements have projections which are engaged by the forward end of a piston sliding along the axis of the drill body within a cylinder bore and are actuated thereby to their cutting positions, with their cutting edges generally radially extending but slightly forwardly divergent, by the hydraulic pressure on the piston of a fluid forced down through the drilling string which carries the bit.

Abstract: A well penetrator has a housing moveable down a well casing with a radially moveable punch being supported in the housing for movement between retracted and extended positions; a fluid jet is discharged from the outer end of the punch with liquid for the jet coming from a tube fixedly positioned at one end in the housing and held in slightly bowed condition when the punch is retracted to permit movement of the punch to its extended position from its retracted condition without the creation of excessive force on this metal tube. The jet creates a bulbous drumstick shaped cavity in the earth which is packed with a gravel slurry which hardens and cannot move into the casing due to the bulbous shape of the hardened slurry mass. Similar procedures are employed using a hose or lance with a nozzle at its outer end; one nozzle embodiment includes radial jets activated to transversely enlarge the cavity at a location spaced from the casing.

Abstract: There is provided a new and useful coring assembly for mounting on the end of a drill string and comprising a core barrel; abrading means on at least a part of the core barrel; a reaming collar mounted about a lower section of the core barrel and selectable between a first condition in which the collar is rotatable with the barrel and a second condition in which the collar is rotatable relative to and slidable longitudinally relative to the core barrel; a housing suspended from the core barrel; a deflection crank extending between the housing and the core barrel; and means within the housing for transferring power from a power source to the crank for selectively rotating the crank for moving the core barrel between a first position in which the core barrel and the housing are aligned and a second position in which the barrel and the housing are not aligned.

Abstract: An underreamer tool has a body with upper and lower portions having an upper cutter blade slot extending transversely through the upper portion and a lower cutter blade slot extending transversely through the lower portion at a right angle thereto. The upper and lower portions have central bores separated by a wall and connected by upper and lower fluid flow passageways bypassing the cutter blade slots. An upper pair of cutter blades mounted in the upper cutter blade slot and a lower pair of cutter blades mounted in the lower cutter blade slot move between a retracted position within the slots and an extended position outward therefrom. An upper piston in the central bore above the upper cutter blade slot has its bottom end engaged on the upper cutter blades and a lower piston in the central bore above the lower cutter blade slot has its bottom end engaged on the lower cutter blades.

Abstract: The present invention comprises a method and apparatus for simultaneously drilling and casing a wellbore. More specifically, the apparatus comprises and outer conduit string containing an inner drill string carrying a bit capable of drilling a wellbore of greater diameter than the outer string. The drill string may be adapted to drill a nonlinear wellbore by offsetting the drill bit from the longitudinal axis of the outer string, and the drill bit is preferably retractable to permit withdrawal of the drill string after the wellbore is completed, leaving the outer string of casing or liner in place. The wellbore is drilled by rotating the drill bit and advancing the drill string by pushing from the surface, and the outer string is advanced by being pulled along by the drill string.

Abstract: A bottom hole assembly is described having a bit driven by a downhole motor and stabilizers located above the motor on the drill string. A subassembly is also provided for controlling the bit trajectory that is operational on demand at the rig site. The subassembly comprises an underreamer located directly above the bit. The underreamer is hydraulically actuated to retract and extend the cutters.

Abstract: An underreamer tool has a generally cylindrical body with a threaded top end for connection to a tubing string, a threaded lower portion to receive a drill bit, and a longitudinal fluid passageway extending centrally through the body. The body has three flat surfaces formed on its exterior in circumferentially spaced relation to define a generally triangular cross section intermediate the top and bottom ends of the body. A cutter blade is pivotally mounted on each of the flat surfaces. A piston is slidably received in a bore in the upper portion of the body and has central fluid passageway therethrough. Push rod members are connected to the piston inside the body and each has an exterior portion slidably mounted in a slot on the exterior of the body engaging the cutter blades for moving them between a retracted position against the body and an extended position outward therefrom.

Abstract: An underreamer tool has a body with upper and lower portions having an upper cutter blade slot extending transversely through the upper portion and a lower cutter blade slot extending transversely through the lower portion at a right angle thereto. The upper and lower portions have central bores separated by a wall and connected by upper and lower fluid flow passageways bypassing the cutter blade slots. An upper pair of cutter blades mounted in the upper cutter blade slot and a lower pair of cutter blades mounted in the lower cutter blade slot move between a retracted position within the slots and an extended position outward therefrom. An upper piston in the central bore above the upper cutter blade slot has its bottom end engaged on the upper cutter blades and a lower piston in the central bore above the lower cutter blade slot has its bottom end engaged on the lower cutter blades.

Abstract: A drill extension is inserted between the drill rod and the drill bit, the drill extension having extendible cutting devices to counterbore the hole drilled by the drill bit for receiving a casing. The cutting devices are flush with the outer surface of the drill extension when not in use, and are pivoted to be expanded by centrifugal force and water pressure when in use. The counterbore is sized to receive the outside diameter of the well casing; and, the cutting devices are retracted to pass up through the casing.

Abstract: A drilling bucket apparatus for expanding a bore-hole bottom for a cast-in-place pile. Drill bits are pivotally suspended from the upper portion of a drill pipe, which is a main frame of the apparatus, and are expanded and retracted radially by means of hydraulic cylinders. A bucket is attached to the lower end of the drill pipe and scrapers are installed on the side of the bucket. The scrapers are arranged to open and close sideward, following the movement of the drill bits. During drilling work, the apparatus is suspended from a kelly bar of a drilling machine. When the apparatus is rotated and the drill bits are expanded, the whole expanded shape of a bore-hole bottom is drilled simultaneously and cuttings are scraped into the bucket by means of the drill bits and the scrapers. Further, a bottom lid of the bucket can be released by operating a hydraulically-actuated opening laver, whereby, cuttings are discharged automatically.

Abstract: A tubing bit opener is disclosed having upper and lower cutters with the lower cutters being carried by mounting blocks having bevelled edges which are received in matching undercut grooves in the tubing bit opener. The upper cutters are attached to arms which are slidable within inclined pockets of the tubing bit opener for inward and outward movement relative to the tubing bit opener. Both the mounting blocks carrying the lower cutters and the arms carrying the upper cutters are easily removable for maintenance and repair. The lower mounting blocks are held securely in place by the drill body. Because the surfaces of the lower mounting blocks extend laterally along a considerable extent of the adjacent lowr cutters, the cutters are supported for stable rotation without vibration. The tubing bit opener is typically used to sink six inch diameter or larger caissons in any rock formation on land or under water.

Abstract: A hydraulically operated underreamer or reamer for enlargement of boreholes is to be connected to a rotating drill string. An outer movable cylinder extends the entire length of the reamer for protection of inner parts thereof. Cutter support arms are movable rectilinearly between an operative state whereat they extend from the cylinder and a closed state whereat they are completely retracted within the cylinder. Cutters are mounted on the support arms and are rectilinearly movable with support arms through openings in the cylinder.

Abstract: In a cutting or hewing roll there is, for increasing the cutting width, arranged at least one lateral front surface of the roll a tool carrier being swivellable relative to the axis of the cutting or hewing roll and receiving hewing or cutting tools. For the purpose of swivelling the swivellable tool carrier there is preferably provided a cylinder-piston-aggregate arranged within the interior of the roll and extending essentially in parallel relation to the axis of rotation of the roll.

Abstract: A downhole cutting tool, specifically adapted to function as an enhanced diameter clean-out tool, includes longitudinal bores which are opened to fluid flow when cutting members are moved to their extended positions. Upper and lower subassemblies are connected through an adapter which establishes an angular offset between an upper pair of extendible members and a lower pair of extendible members, which upper pair functions as a stabilizing structure to stabilize rotation of the tool and which lower pair functions as an enhanced diameter cutter.

Abstract: A tool for use downhole has an elongate body, arms movably mounted on the body and means for controlling movement of the arms between an operational position and a retracted position. Movement of the arms is controlled by a motor and a transmission, according to one aspect of the invention the arms being suspended independently of one another and in a second aspect of the invention, movement of the arms being controllable remotely from the tool.

Abstract: A narrow diameter reaming tool can ream a hole which is up to ten times the diameter of the tool. The cutting arms of the tool are of a type such that if there is an excessive load on an arm, the arm will fracture rather than bend.

Abstract: A divided bucket type rotary excavator comprises cutter units constructed by dividing a bottomed cylindrical bucket into plural portions, whose curved sidewalls and bottom plates are provided with bits on their leading edges. The cutter units are arranged about a center shaft radially movably toward and away from the center shaft.The center shaft consists of an outer hollow cylinder having a polygonal cross-section and an inner hollow cylinder slidably fitted in the outer hollow cylinder.