Abstract: Described examples relate to a downhole fluid heater, comprising a fluid heating assembly comprising a heating chamber for receiving a fluid. The fluid heating assembly is configured to agitate a heat transfer fluid in the heating chamber so as to impart thermal energy and heat the heat transfer fluid.

Abstract: A portable electrical assembly includes an electric motor, a power module, and an electric motor power cord. The electric motor power cord is placed within a cavity of a housing of the portable electrical assembly and is operatively connected to the electric motor at first end and to the power module at a second end. The electric motor power cord is configured to move in response to the movement of the electric motor without the creation of sharp bends along its length as the electric motor moves between all of its possible operating positions including an extended position and a resting position and a plurality of intermediate position between the extended and resting position.

Abstract: A hydrojet rotary drill bit (10) is provided for drilling a hole in a subsurface formation. The bit body (12) includes a plurality of axially extending ribs (16a, b, c, d, e, and f) and a flow channel between adjacent ribs. A plurality of cutting elements are fixedly mounting on a respective one of the plurality of ribs. A plurality of flow nozzles (20a, b, c, d, e, and f) made on respective one of the plurality of ribs to direct fluid (mud) to a respective one of the plurality of cutting elements to clean and cool the cutting elements.

Abstract: A well tool for removing metal debris from a well bore has a magnet element, an anti-torque anchor, a debris removal unit, a debris container and a first connecting end for a rotatable well string. The magnet element has a cylinder-shaped housing. The removal unit has a helix-shaped longitudinal guide element arranged on the housing. The anchor is connected to the housing or the guide element such that actuation of the anchor during use will prevent rotation of the housing or the guide element, respectively, relative the well-bore. The container has an opening at the end of the housing. The housing and the guide element are rotatable relative each other, and configured such that metal debris accumulating on the housing during use is guided by the guide element towards the opening of the container when the anchor is actuated and the first connecting end is rotated.

Abstract: A junk recovery tool may include a longitudinal axial mandrel, a plurality of junk recovery baskets, and at least one junk recovery sensor. The plurality of junk recovery baskets may be spaced apart and attached to the longitudinal axial mandrel. A first one of the junk recovery baskets may be disposed uphole of a second one of the junk recovery baskets. Each of the junk recovery baskets may include a plurality of apertures, allowing a drilling fluid to pass through the junk recovery basket while collecting junk from the drilling fluid. The at least one junk recovery sensor may be disposed in one of the plurality of junk recovery baskets. The at least one junk recovery sensor may be operable to measure an amount of collected junk in the one of the plurality of junk recovery baskets. The present disclosure also includes systems and methods incorporating the junk recovery tool.

Abstract: An apparatus and method for drilling an underground borehole is presented, wherein pressurized air may be used to discharge out of the borehole cuttings created by a cutter head. A casing may be secured to the cutter head such that the cutter head and casing may be rotatable together as a unit. The casing may have larger and smaller diameter sections. An auger may be disposed adjacent the front of the casing.

Abstract: A shaft enlargement arrangement for a boring system is provided, the shaft enlargement arrangement comprising a hollow column proximate a lower end of the boring system; a first cutter head that is rotatably fitted to the hollow column, with first drive means being provided to rotate the first cutter head relative to the hollow column so as to bore downwardly a hole having a diameter corresponding substantially to the diameter of the first cutter head; and a boring head arrangement fitted to an operatively lower end of the column, the boring head arrangement terminating in a second cutter head to bore a leading hole as the boring system proceeds to bore downwardly. In an embodiment, the first cutter head comprises a support body carrying a winged arrangement, the support body being rotatably fitted to the column, the winged arrangement comprising a plurality of wings extending from the support body, each wing being fitted with, or comprising, a plurality of first cutter elements.

Abstract: A conveyance system for moving a conveyance along a mine shaft during shaft construction, comprising: a first guide section; a second guide section located along the mineshaft in series with the first guide section, the conveyance being movable along the first guide section; and a head section for receiving the conveyance, the head section cooperating with the first guide section to enable the conveyance to travel from the second guide section along the first guide section when received by the head section.

Abstract: A vertical shaft drilling rig which includes a derrick and a flatcar element. The rig includes a drill pipe connecting to the derrick, a pipe joint provided on the drill pipe, a device for stabilizing cutterhead pressure connecting to the drill pipe, a torque amplification driver at which the device for stabilizing cutterhead is installed, a cutter head connected to the torque amplification driver, a separate plant on the ground surface, a muck removal system transporting the muck produced to the separate plant, an electric cabinet, a hydraulic station, a power line, and a deep shaft line extension device between the hydraulic station and the power line. The torque amplification driver includes a pressure balance valve, a planetary reducer, a drive flange and a main bearing. The deep shaft line extension device includes a float, a pulley assembly, a line reel, a steel wire and a winch.

Abstract: A device and method for sinking a shaft during a sinking cycle, in which a support unit is moved once and a boring unit is moved at least twice by means of support cylinders and displacement cylinders. Due to such configuration, an efficient sinking operation is obtained.

Abstract: A fluid removal device removes fluid and mud from a borehole during a directional drilling operation, thereby resisting any tendency of the fluid and mud to exit the borehole through any weaknesses that may be present within the surrounding soil. The fluid removal device is secured to a directional drill, and moved through the borehole, perhaps simultaneously with a reamer or a pipe to be installed within the borehole. Fluid and mud are collected within the device. Increased pressure, for example, from compressed air, is used to bias the fluid and mud out of the device and out of the borehole.

Abstract: An expandable diameter drill bit includes a cutting blade having receiving and contacting ends, the receiving end having a pivot shaft and the contacting end having a tip. A drill bit includes a drill head body having an upper attachment portion and a lower body portion, the lower body portion defining a blade opening for receiving the receiving end of the cutting blade and a bolt receiving hole on opposing sides transverse the blade opening. The drill bit includes a torsion spring, a first blade leg, and a second body leg. The blade bolt passes through the bolt receiving holes and the pivot shaft and secured with a set screw. The first blade leg is coupled to the cutting blade with a spring retainer bolt, the second body leg is coupled to the drill head body, and the torsion spring biases the blade outwardly from the drill head body.

Abstract: A ground drill system (10) has a drill string 14 which forms first and second mutually isolated fluid paths (16 and 18) respectively. The drill string (14) has an up hole end (20) coupled to a dual circulation rotation head (22) and a down hole end (24) which is coupled to a drilling tool (12). The drilling tool (12) is operated by the flow of fluid delivered through the first flow path (16). A second fluid outlet (26) is provided intermediate the up hole end (20) and the drilling tool (12). The outlet (26) is in fluid communication with the second fluid flow path (18) and located a constant or fixed distance from the drilling toll (2). The second fluid outlet (26) discharges a flushing fluid flowing through the flushing flow path (18) into a hole being drilled by the drilling system (10). The rotation head (22) provides torque to the drill string (14) and thus the drilling tool (12).

Abstract: A wellbore machining device is proposed for machining a tubular component of a wellbore. The device includes a control unit at the surface level of the wellbore and a down-hole tool unit connected to the control unit through a wire line. The tool unit includes an elongated guide member, a tool member movably supported on the guide member with respect to at least three axes of motion and a plurality of actuators controlled by the control unit and adapted to move the tool member with respect to the axes of motion. The tool unit further includes two anchor members each mounted to an axial end of the guide member and adapted to releasably clamp the tool unit to the tubular component. The control unit and the tool unit form a computer numerical control device (CNC device) wherein the actuators are electric servo motors controlling an actual position of the tool member with respect to a path and/or a sequence of desired position defined by the control unit.

Abstract: An apparatus, system and method is disclosed for processing geological solids or wellbore cuttings generated by excavation or drilling under a body of water. An apparatus for processing solids in association with a riser may employ a solids processing apparatus having a central cavity that is substantially free of mechanical obstructions. The central cavity may be positioned in-line with the riser. The apparatus may be adapted for receiving solids within the central cavity and reducing the particle size of the solids by action of a cutter assembly which is positioned outside of the central cavity. The cut and processed solids may be pumped to the surface of the water.

Abstract: In forming a mine shaft for an underground mine, earth excavated by a boring machine may be transported upwardly by a handling unit to a transfer station where it may be transferred into skips, which may be raised and lowered along skip guides within the shaft hole for transport of the excavated material to an earth surface region. The transfer station may be moved downwardly as excavation progresses.

Abstract: Drilling tool (1) for drilling a well downhole where fluid is surrounding the tool and where the tool has a housing (15) and is connected to an electrical conducting means, such as a wireline. The drilling tool has a drilling head (2) and a fluid cleaner (3) for removal of elements, such as debris and formation pieces, from the fluid while drilling downhole. The fluid cleaner has a chamber (4) and a filter (5) within the chamber for separation of the elements from the fluid. The tool further comprises a pump (8) for pumping the fluid into the chamber through an inlet (11) in the drilling head (2) and through the filter before entering the well again. Furthermore, the tool comprises a driving unit for driving the pump and the drilling head.

Abstract: An apparatus and method for drilling deeper and wider well bores is provided. The apparatus includes a motorized drill head for cutting and shredding ground material; a separate excavation line; a separate fluid delivery line; and a separate close loop engine cooling line. The excavation line consists of multiple connected stationary segments of the main pipe with periodical segments of an in-line excavation pump. Alternatively, in another embodiment, excavation line consists of multiple connected segments of the main stationary pipe with rotating continues screw inside. The close loop cooling line consists of one heat exchanger in the motorized drill head and one on the ground surface in the binary unit where fluid is cooled and in process electricity produced which can be used as a supplement for powering drill head, pumps, equipment, etc.

Abstract: An apparatus, system and method is disclosed for processing geological solids or wellbore cuttings generated by excavation or drilling under a body of water. An apparatus for processing solids in association with a riser may employ a solids processing apparatus having a central cavity that is substantially free of mechanical obstructions. The central cavity may be positioned in-line with the riser. The apparatus may be adapted for receiving solids within the central cavity and reducing the particle size of the solids by action of a cutter assembly which is positioned outside of the central cavity. The cut and processed solids may be pumped to the surface of the water.

Abstract: A method for drilling a well with a drilling apparatus comprising a drill string and a bit, comprising attaching a cleaning tool comprising a coaxial pipe and at least one vortex spinner to a portion of the drill string above the bit, inserting the drill string into a wellbore, extending the wellbore while simultaneously pumping fluid through the cleaning tool to create a fluid flow, and loosening debris attached to the wellbore.

Abstract: A downhole rotational rate control apparatus, adapted for coupling to the lower end of a drill string, includes a progressive cavity (PC) motor, a driveshaft, a mud flow control valve, and an electronics section. Drilling mud flowing downward through the drill string is partially diverted to flow upward through the PC motor and out into the wellbore annulus, with the mud flow rate and, in turn, the PC motor speed being controlled by the mud flow control valve. The control valve is actuated by a control motor in response to inputs from a sensor assembly in the electronics section. The PC motor drives the driveshaft and a controlled downhole device at a specific zero or non-zero rotational rate. By varying the rotational rate of the PC motor relative to the rotational rate of the drill string, the tool face orientation or non-zero rotational speed of the controlled device in either direction can be varied in a controlled manner.

Abstract: A device for driving boreholes in the ground, having a rotationally driven main shaft with a shaft journal whose axis (B) forms an acute angle with respect to the axis (A) of the main shaft. A drill head is mounted such that it can rotate about the axis (B) of the shaft journal and has a circumferential region which runs on a complementary circumferential region, wherein the complementary circumferential region can be set rotating.

Abstract: The present invention generally relates to an apparatus and method for use in a wellbore. In one aspect, a downhole tool for use in a wellbore is provided. The downhole tool includes a housing having a shaped inner bore, a first end and a second end. The downhole tool further includes a rotor having a plurality of extendable members, wherein the rotor is disposable in the shaped inner bore to form at least one chamber therebetween. Furthermore, the downhole tool includes a substantially axial fluid pathway through the chamber, wherein the fluid pathway includes at least one inlet proximate the first end and at least one outlet proximate the second end. In another aspect a downhole motor for use in a wellbore is provided. In yet another aspect, a method of rotating a downhole tool is provided.

Abstract: An adjustable hole cleaning device is provided for cleaning a hole in a subterranean formation. A drillstring containing the device is rotated to drill a hole through the subterranean formation. While rotating the drillstring, drilling fluid is circulated through the drillstring and the device into the hole. In response to an increase in a hydrostatic pressure of the fluid in the drillstring, cleaning elements are extended from the device to clean accumulated cuttings from the drilled hole. The cleaning elements may clean the accumulated cuttings by agitating the circulating fluid in the hole. In response to a decrease in a hydrostatic pressure of the fluid in the drillstring, the cleaning elements may be retracted back into the device. The device may also include a set of ports which hydraulically open in response to the increase of hydrostatic pressure in the drillstring to disperse drilling fluid into the hole for cleaning accumulated cuttings.

Abstract: A directional drill for transport via rail tracks and railwheels associated with the directional drill to an operating location. The directional drill has a first frame associated with a set of pneumatic tires for movement of the directional drill onto and off of the tracks and, when removed from the tracks, for movement to the operating location. A second frame is rotatably attached to the first frame and allows the drilling configuration of the second frame to be more nearly horizontal relative to the first frame. Hydraulic lines move during drilling and are maintained in a predetermined configuration to reduce vibration and chaffing.

Abstract: A drilling apparatus having cuttings removal structure to reduce balling thereof and to help prevent the accretion of portions of chips and debris from drilling thereon and/or the accretion of portions of drilling fluids thereon. The drilling apparatus comprises an apparatus body having a connection thereon and structure for contacting cut portions of the earth formation. The contacting structure may include chip breakers and flails or combinations thereof.

Abstract: A drilling apparatus having cuttings removal structure to reduce balling thereof comprising an apparatus body having a connection thereon, and structure for contacting cut potions of the earth formation. The contacting structure may include chip breakers, flexible cables, rotating nozzle assemblies, rotating turbine wheel assemblies, rotating vane assemblies, flails or combinations of these. The apparatus may include elastomeric portions and/or movable potions. The drilling apparatus may comprise a drill bit, drilling stabilizer, drill collar, reamer, downhole motor, etc.

Abstract: A method for forming substantially lateral boreholes from within an existing elongated shaft includes positioning a drilling unit within the existing shaft, bracing the drilling unit against a wall surrounding the existing shaft to transmit forces between the drilling unit and the medium surrounding the wall, and applying a drilling force from the drilling unit to cut through the wall of the existing shaft and form the substantially lateral borehole in the surrounding medium. A preferred apparatus for practicing the method includes an extendable insert ram within the drilling unit for extending a drill bit from the drilling unit and applying a drilling force to the drill bit to cut through the wall of the existing shaft. A supply of modular drill string elements are cyclically inserted between the insert ram and the drill bit so that repeated extensions of the insert ram further extends the drill bit into the surrounding medium to increase the length of the lateral borehole.

Abstract: A method and apparatus for removing drilling mud within entrained cuttings is provided using a pump for forcing fluid into a borehole, such that the fluid mixes with cuttings formed during the formation of the hole. The pipe receives the fluid and entrained cuttings at a first end of the pipe and returns the fluid and entrained cuttings to the surface at the second end of the pipe. At the first end of the pipe, air is injected into the drilling fluid with entrained cuttings to form bubbles therein, thereby increasing the velocity of the fluid and entrained cuttings through the pipe. In one alternative embodiment, a suction is provided at one end of the pipe to increase the speed of fluid and entrained cuttings therethrough. In a third embodiment of the present invention, an Archimedes screw is used to remove the fluid and entrained cuttings from the borehole.

Abstract: A method and apparatus for enlarging an inverted arcuate underground path between two surface locations is disclosed, where the cuttings from the enlarging are removed. After the drilling of a pilot borehole, and possibly after some reaming operations, a reamer and hole cleaner are pulled through the path, with the reamer rotating as the drill string in the path rotates. The rotation of the drill string also powers a positive displacement pump inside of the hole cleaner, which pumps fluid and entrained cuttings to the surface behind the hole cleaner. Fluid may also be pumped into the reamer from behind the hole cleaner, preferably by way of an inlet pipe which surrounds the outlet from the pump. The hole cleaner includes an agitator, also powered by the rotation of the drill string, which agitates the fluid and cuttings while the drill string is rotated but is not being pulled to the surface.

Abstract: A hole cleaning device 100 includes a housing having a porous region to communicate cuttings from a bore hole to the interior of the housing. A Venturi-effect pump creates a suction to draw cuttings from the hole into the housing. An outlet pipe coupled to the Venturi pump transports the cuttings out of the housing.

Abstract: An apparatus for removing debris from a bore hole comprises a housing having apertures formed therein such that rotation of the housing causing entrapment of the cuttings from the bore hole. The positive displacement pump comprises a rotor surrounded by a stator coupled to the housing such that rotation of the stator rotates the housing. The positive displacement pump is operable to pump material from the housing responsive to relative movement between the rotor and stator. A motor rotates the stator, thereby cleaning the bore hole.

Abstract: A device for borehole hydraulic mining includes a pipeline for delivering fluid into the hole accommodated inside a pipeline for bringing pulp to the surface and featuring a constant inside diameter along the entire length of this pipeline. The pipeline for delivering fluid into the hole carries a hydraulic jet. The device also has a hydraulic elevator with a fluid and pulp mixing chamber secured to the lower end of the pipeline for bringing pulp to the surface, and a nozzle secured to the lower end of the pipeline for delivering fluid into the hole. The fluid and pulp mixing chamber and the nozzle of the hydraulic elevator enclose the pipeline for drilling fluid into the hole with clearances allowed.

Abstract: Pipe-driving apparatus used to create a pipe line of small diameter uses a pressing station in an access trench to drive in pipe sections one by one. A boring head and conveyor worm operates at the front of the pipe line in a working pipe section on which a cutting shoe is swivably mounted. The worm is a spiral flight on a drive shaft which runs within an open fronted container on which a drive unit for the boring head and the worm is mounted. Hydraulic bracing units mounted to the container can be swung out and engaged with stops in the working pipe section to brace the container during the filling operation. Projections on the container engage with the shoe and the bracing units can be used to steer the shoe. When the container is filled the bracing units re stowed and the container is withdrawn back down the pipe line to the access trench for discharging the material.

Abstract: A downhole tool positioned intermediate the mud motor and the drill bit, for reducing the hydro-static head near or around the bit. What is provided is an upper body portion threadably attachable to the mud motor and having an internal shaft with a bore therethrough for allowing mud to flow down the shaft rotatable during the the operation of the tool. The upper body portion further includes a gear member on the outer wall of the shaft for rotatably engaging the pair of upper gear members which imparts rotation to a pair of lower gear members for further imparting rotation to a fan member located in the lower portion of the tool.

Abstract: A shaft drilling machine comprises a drill head carrying drill tools thereon, a device for guiding the drill head in a shaft, a device for advancing the drill head in the shaft, and drive aggregates which are lowered into the shaft together with the drill head and driving the latter. A sluice for providing a rinsing fluid is arranged in a pilot drill. A rinsing conduit and an ascending conduit for extracting from the shaft a drilled material-rinsing fluid mixture generated during the drilling operation are connected to the sluice which is formed as a bucket wheel.

Abstract: A trench excavator capable of excavating a trench of a rectangular section suitable for formation of an underground diaphragm wall. The underground diaphragm walls are now applied as underground structures replacing caissons, rigid foundations for multistory or tower like buildings, underground tanks and the like. In the trench excavator according to the invention, a pair of drum cutters and a ring cutter interposed therebetween form one unit and a plurality of such units are arranged parallel to one another, whereby an unexcavated portion produced between the drum cutters can be cut out by the ring cutter, leaving no unexcavated portion.

Abstract: A shaft boring machine including a rotatable cutterwheel assembly with a horizontal axis mounted on a carriage having vertical travel. The carriage is mounted on a slewing base frame and rotates about the vertical axis of the machine. An excavating unit for muck removal is mounted opposite the cutterwheel on the slewing base frame and loads directly from the shaft bottom into a muck hopper. When the hopper is full, it is discharged into a hoist bucket which is hoisted to the surface. The machine is positioned in the shaft by upper and lower gripper systems. Walking cylinders between the two gripper rings advance the machine up or down the shaft.

Abstract: An earth boring or shaft sinking apparatus in which a column is continuously rotatable about its axis, the column including a cutting wheel at one end rotatable about a wheel axis normal to the axis of the column, the cutting wheel including sprockets mounted about the wheel axis, the sprockets providing engagement for an endless bucket-carrying chain for direct conveyance of cuttings from the bottom of a hole to the top end of the column, which includes another set of sprockets for the endless bucket-carrying chain and discharges the cuttings into a feed bin. The cutting wheel is continuously rotated about the column longitudinal axis, as well as its wheel axis of rotation.

Abstract: A shaft drilling machine has a circularly moving drilling head. The drilling head is angularly oriented with respect to the longitudinal axis of the shaft sought to be drilled. Loosened material is transported from the lower portion of the shaft by pickup means, moving with the drilling head, and taken to the upper portion of the angularly oriented bottom of the shaft, whereupon the loosened material or borings slide, by gravity, to a centrally located vertical conveyor mechanism for final removal of the material or borings from the shaft.

Abstract: An in-hole fluid motor assembly has a clutch engageable between the bearing housing and the drive shaft which is rotatable in the bearing housing, to connect the housing to the shaft and enable rotation of the bit by the housing. The clutch is engaged without increasing the load imposed on the bit. Drilling fluid in or flowing through the assembly and into the drive shaft is employed to hold the clutch disengaged while the circulating pump is running, and a spring normally acts to engage the clutch when the circulation of fluid is diminished by stopping the pump. In one form, the clutch may be automatically engaged if circulation is blocked and the pump continues to apply pressure to the fluid.

Abstract: An apparatus for the sinking of a shaft in which a machine platform can be anchored against the wall of the incipient shaft and carries an orbiting tool for cutting away the floor of the shaft, thereby dumping the detritus into a pilot-bore hole continuously drilled by a pilot-bore unit. The latter has a head for advancing the pilot bore and is provided with a worm conveyor running centrally through the shaft to transfer the detritus to a bucket on a loading platform disposed above the main platforms and connected thereto for feed cylinders. The platforms have cylinder arrangements whereby they can be independently anchored to the vertical wall of the shaft.

Abstract: An earth boring machine with a rotating cutter head having a multiple of individual cutters positioned at different distances from the center of rotation and angularly spaced from one another on the cutter head while the cutter head itself is shaped to direct the cuttings into a collecting area, which may be under the center of the rotary head or which may be concentric about the center area, has elevator means, which may be mechanical, hydraulic or pneumatic, to remove the cuttings from the collection area, and has one or more crushing rollers thereon arranged to crush cuttings which are too large for effective removal by the elevator means into small chips or fragments together with barrier means for restraining such oversize pieces in the path of the crushing roll or rollers so as to prevent their entry into the collection area until they have been adequately crushed. The barrier means so provided are arranged to permit the smaller fragments and chips to move into the collection area with little impedance.

Abstract: Processes and apparatus in the field of Terradynamics, e. g. projectile penetration into soils and rocks, employing "open chamber" firing systems using "Trounds" (triangular rounds of ammunition). Included are salvo firings of small calibre projectiles for "shock wave" interaction drilling application of residual gun gases to actuate drill heads and/or reamers; a continuous self-contained feed system for feeding ammunition to be fired and removing and storing the used cases; remote self contained powering of the ammunition feed and storage by recoil of the gun, residual gun gases, electrical batteries, and/or combinations thereof; absorption of excess residual gun gas in an ambient environment of over 5000 psi external to the gun; and automatic clearing of the gun barrels from mud and or debris when embedded in a high pressure drilling mud external to a gun drill.

Abstract: A cutter wheel is mounted at the lower end of the machine for rotation about a horizontal tubular support. Cuttings are picked up by buckets on the cutter wheel and are directed into the tubular support to be received by an endless bucket conveyor which carries them upwardly to a discharge station. As the machine is advanced the cutter wheel is rotated to make a first cut in the shape of the leading portion of the cutter wheel. The cutter wheel is then retracted out from the cut and is rotated about the axis of the hole. This repositions the cutter wheel so that when it is advanced again it will make a second cut which crosses the first. This procedure is repeated until the desired cross-sectional configuration (e.g. circular) of the hole is obtained.

Abstract: The present invention relates to belling apparatus for forming a bell shaped recess at the lower end of a pier bore and is concerned primarily with such apparatus in which spoil generated by cutting the recess is continuously removed by an auger.

Abstract: This is a deep well drill employing a Nelson air motor, a Nelson engine or other air motor for drilling power at the face of a petroleum or other deep well and having a cable and tube attached thereto and suspended from spools on a drill rig. A cutting container is attached to the drill to remove cuttings without mud. Drills for varying types of rock strata are provided. A type of foldable casing employed permits the use of the same diameter casing throughout the entire well of any depth, including deep wells to over 25,000 feet. Expandable bits at the end of the cable are provided for drilling selectively larger diameters for foldable casing walls and for safety valve and flow control anchors. The bits are also contractable for unobstructed travel up and down the well.