Abstract: The invention provides a rock drilling bit with a plurality of cutting teeth raked into the cut of the drilling bit. Such teeth are oriented at an angle of at least about 30 degrees relative to an imaginary line normal to a front surface of the cutting head from which the cutting teeth project. Such an arrangement provides the desired shear cutting force against the rock face while simultaneously reducing the shock and vibration applied to sonde housing and the drill string. The bit according to the invention may further incorporate a rear, frustoconical crushing surface that defines a space or zone crescent-shaped in cross-section that narrows from front to rear, and an improved replacable tooth for use on a rock drilling bit.

Abstract: A downhole drilling apparatus for interconnection in a casing or liner string having a drill bit disposed thereon for enabling the drilling of intersecting wellbores without removal of the drill bit is disclosed. In a disclosed embodiment, the apparatus comprises a housing having a window. A whipstock is disposed within the housing. Between the window and the whipstock is a filler. The whipstock and the filler define a central bore providing a fluid path through the apparatus. A back pressure valve may be disposed within the central bore to prevent back flow of fluids through the apparatus. Once the total depth of an initial wellbore is reached, the casing or liner string, including the apparatus, may be cemented in place. Thereafter, an intersecting wellbore may be drilled by laterally deflecting a second drill bit with the whipstock through the window of the housing.

Abstract: An orienter for controlling the drilling direction in a well. A main body 40, 23 is couplable to a drill string, and a nose tubing 50 is movably mounted by a universal joint in the main body. A collar 42 with a bore 43 engages in a cam-like manner with an extension 26 of the nose tubing on the drill string side of the universal joint. The collar is movable longitudinally ‘a’ to control the magnitude ‘b’ of the nose tubing, and circumferentially ‘c’ to control the azimuth ‘d’. The nose tubing is aligned on both sides of the universal joint and the bore of the collar is angled relative to the main axis of the main body. The collar may be hydraulically or electrically controlled.

Abstract: A drill head for an apparatus for directional boring according to the invention includes a bit, a holder for a device for detecting angular orientation of the bit, and a hammer including a striker for delivering impacts to the bit, wherein the bit assembly, holder and hammer are connected head to tail with the bit at a front end. The bit of the invention has a frontwardly facing main cutting surface having a plurality of main cutting teeth disposed thereon and a gage tower extending radially outwardly from the main cutting surface, which gage tower has at least one frontwardly facing gage cutting tooth thereon suitable for cutting over an angle defined by less than a full rotation of the bit. The device for detecting angular orientation is in a predetermined alignment with the gage tower so that it determines the orientation of the gage tower relative to the axis of rotation of the drill head.

Abstract: A bottom hole assembly for horizontal directional drilling that improves the accuracy of surveying while boring by enabling the progress of the bore to be monitored and tracked with the aid of a sonde. In one embodiment the sonde is received in the wall of a area of a mud motor surrounding the bearing mandrel, in another embodiment the sonde is carried in the wall of a collar surrounding the bearing mandrel housing, and in an additional embodiment the sonde is carried in an adapter between the bearing mandrel and the bit.

Abstract: A hydraulic percussion drill includes a piston hammer disposed in a cylinder for reciprocating movement in response to pressure fluid acting continuously on one transverse face of the piston hammer and in response to valving of pressure fluid alternately to an opposed piston face of the piston hammer by a tubular sleeve valve disposed around the piston hammer. The drill includes a percussion bit configured to have a face portion disposed at an acute angle with respect to a plane normal to the bit and the drill central axis. Cooperating spiral splines on the bit and a bit chuck provide for directional drilling using a method which includes causing the bit to receive impact blows without rotating the cylinder housing to initiate a deviated drillhole.

Abstract: The apparatus includes an annular cam rotatably located in a housing with a drill shaft extending through the cam and housing. The shaft can be rotated for drilling purposes and be moved longitudinally in the housing for shifting purposes. The cam has grooves in its outer surface for receiving a cam follower carried by the shaft which rotates the cam as the shaft is moved longitudinally for shifting purposes. The shaft may be moved longitudinally in one direction to a position to engage members of a clutch such that when the shaft rotates, it rotates the housing. The shaft is movable in an opposite direction to disengage the clutch members and then is movable to locate the cam follower in the groove at different positions to allow the operator to control the longitudinal position of the shaft for turning purposes or for drilling straight.

Abstract: A rotatable steerable drill string in which guidance module controls the direction of the drilling. A magnetorheological fluid in the module supplies pressure to pistons that apply forces to the wall of the bore and thereby alter the direction of the drilling. The pressure applied by the magnetorheological fluid is regulated by valves that apply a magnetic field to the fluid so as to increase or decrease its fluid shear strength thereby controlling the actuation of the pistons and the direction of the drilling.

Abstract: A method for orienting a rotary drilling system comprised of a rotatable drilling string, a drilling string communication system and a drilling direction control device, the drilling direction control device comprising a deflectable drilling shaft connected with the drilling string. The method for orienting the rotary drilling system may involve the steps of orienting the drilling string at a desired orientation and sensing the desired orientation of the drilling string with the drilling string communication system. Further, the method involves the steps of communicating a desired orientation of the drilling string to a drilling direction control device and then actuating the drilling direction control device to deflect the drilling shaft to reflect the desired orientation of the drilling shaft. The desired orientation of the drilling shaft may be communicated directly to the drilling direction control device or to the drilling direction control device through a drilling string communication system.

Abstract: The invention relates to a system for coiled tubing drilling of substantially horizontal shallow depth boreholes for installation of transmission or conveyance lines. A mobile platform mounts a coiled tubing reel and an adjustably mounted injector head. On the leading end of the coiled tubing is a drilling assembly, including a drill, a drill motor, and an orienter. Once the borehole has been drilled by pushing the drilling assembly through the borehole and exiting the earth's surface, a back reamer may be attached for enlarging the borehole as the coiled tubing is pulled back through the borehole. Once the borehole has been properly sized, the transmission or conveyance line may be attached to the leading end of the coiled tubing and the transmission or conveyance pipe pulled back through the borehole.

Abstract: A downhole steering tool will steer the angle of the drill bit for drilling directional wells. The steering tool includes a steering housing which is mounted on the drill string above the drill bit. The steering housing can be held against rotation while the drill string rotates to cause the bit to drill in a desired direction. Guide members are mounted on the steering housing. The guide members may engage the borehole. The guide members can be turned about an axis which is perpendicular to the longitudinal axis of the steering housing. Turning the guide members causes the steering housing to rotate relative to the borehole in one direction or the other as the housing slides downward in the borehole. Reorienting the steering housing allows steering of the drill bit.

Abstract: This invention provides a bottomhole assembly that contains a thruster for applying an axial force on the drill bit during drilling of the wellbore. The bottomhole assembly includes at least one sensor which provides measurements for determining a parameter of interest relating to the drilling of the wellbore. A power unit supplies power to the thruster to move a member toward the drill bit to apply the force on the drill bit. A processor operatively coupled to the thruster controls the magnitude of the force generated by the thruster in response to one or more parameters interest.

Abstract: In general, the present invention provides a modular drilling assembly having a module for contactless power and data transfer over a nonconductive gap between rotating and non-rotating members of a steering module. The gap usually contains a non-conductive fluid, such as drilling fluid, or oil for operating hydraulic devices in the downhole tool. The downhole tool in one embodiment is a modular drilling assembly wherein a drive shaft is rotated by a downhill motor to rotate a drill bit attached to the bottom end of the drive shaft. A substantially non-rotating sleeve around the drive shaft includes at least one electrically-operated device. The drilling assembly is modular in that it includes at least one steering module at the bottom end of the drilling assembly that has at least one steering device module that provides power to the force application member.

Abstract: The apparatus serves as a length of drill string and has a valve actuatable from the surface that restricts the drilling fluid channel to produce a pressure drop within the apparatus. The pressure drop is used to move a piston which moves a side loading element against a well bore wall to urge the drill string toward the opposite wall to cause a progressing drill head to change direction. The housing that carries the side load element has a clutch that rotationally disengages the housing from the drill string when the element is extended. The drill string can drill as a rotary system while the side loading element is stationary relative to earth.

Abstract: A method and apparatus for drilling a lateral from a primary wellbore having a short radius-of-curvature. The lateral is drilled by a downhole drilling unit which differs from prior art units of this type in that instead of connecting the drill bit directly to the downhole motor, a length of flexible drill pipe is used to connect the bit to the rotary power output of the motor. This length of flexible drill pipe below the downhole motor allows much larger build-up angles (e.g. 1-3° per foot) which, in turn, reduces the time and expense for short-radius laterals and increase the accuracy of placement of the lateral within the zone of interest (e.g. production formation).

Abstract: A pre-milled window casing on a casing string for allowing a cutting tool inserted into said will to contact the earth through said hole provided in said casing. Portions of a casing section along a casing string have been removed to allow drilling outwardly from the casing string at desired depths along the well. Orientation tools are provided to properly orient the window in the direction of drilling. A whip stock with an orientation nipple is inserted and mated with an orientation slot contained in an orientation sub portion of the casing string to align the whipstock with the window. A drilling tool inserted through the casing is redirected by an upper slanted face of the whipstock through the window where a hole can be bored through the earth to a gas deposit.

Abstract: A drill bit with dropping tendencies includes an active region, a passive region, a biased mass distribution, an uneven torque generation, and an imbalance force vector directed toward the middle of the active region. Cutting elements in the active region of the drill bit may be more aggressive than those in the passive region through manipulation of, e.g., backrake angle, blade length, cutter sizes, blade angles and bit profile. The imbalance force vector may be achieved by manipulation of bit geometric parameters such as cutter radial position, angular position, longitudinal position, and rake angle.

Abstract: A drilling system includes a work string supporting a bottom hole assembly. The work string including lengths of pipe having a non-metallic portion. The work string preferably includes a composite umbilical having a fluid impermeable liner, multiple load carrying layers, and a wear layer. Multiple electrical conductors and data transmission conductors are embedded in the load carrying layers for carrying current or transmitting data between the bottom hole assembly and the surface. The bottom hole assembly includes a bit, a gamma ray and inclinometer instrument package, a propulsion system with resistivity antenna and steerable assembly, an electronics section, a transmission, and a power section for rotating the bit. The electrical conductors in the composite umbilical provide power to the electronics section and may provide power to the power section. The data transmission conduits in the composite umbilical transmit the data from the downhole sensors to the surface where the data is processed.

Abstract: A drilling assembly and a method for directional drilling using the drilling assembly. The drilling assembly comprises a drilling bit, a near bit stabilizer and an adjustable gauge stabilizer. The near bit stabilizer is located a first axial distance from a distal end of the drilling assembly and has a near bit stabilizer gauge which is greater than a nominal drilling assembly gauge. The adjustable gauge stabilizer is located a second axial distance from the distal end, which is greater than the first axial distance, and is adjustable between an extended and retracted gauge. The retracted gauge is less than the near bit stabilizer gauge. A bit drop angle is created between the drilling assembly and the drilling bit, while a stabilizer angle is created between the near bit stabilizer and the adjustable gauge stabilizer.

Abstract: A controllable stabilizer (16; 116) in which an outer sub-assembly (22) is rotatably mounted around an inner sub-assembly (20). An annulus (58; 158) is movably mounted around the outer sub-assembly (22) to be radially displaced in a predetermined direction by selective hydraulic energisation of individual pistons (52; 152) in a piston/cylinder array (48; 148). The piston(s) selected to be energised are determined by a directionally-sensitive control system (18). The outer sub-assembly (22) carries a hydraulic pump (38; 138) operated by a driving mechanism (28; 128) carried on the inner sub-assembly (20); this pump (38; 138) provides hydraulic power for the pistons (52; 152). An alternator (34+56; 134+156) is similarly mounted and driven to provide on-board electrical power for the control system (18).

Abstract: Within a longitudinally-extending main housing having a longitudinally-extending duct, an indexing mechanism comprises a mandrel within the duct and capable of longitudinal movement relative to the main housing; a cam sleeve rotatable with respect to the mandrel but constrained in terms of longitudinal movement with respect to the mandrel, the cam sleeve having an external surface provided with a groove in the form of a closed loop; a cam follower resiliently urged into the groove of the cam sleeve; a main spring tending to urge the mandrel in a first direction along the duct; and a fluid abutment face, on which, in use, fluid under pressure can act to tend to urge the mandrel in a second direction opposite to the first direction; the groove having ramps and associated steps thereby restricting relative movement of the cam follower with respect to the groove, to one direction progressively around the closed loop; the groove having a plurality of rest positions at which the cam follower can rest, depending on

Abstract: The present invention provides an active downhole cutting tool guide device 14 for use in a hole 17 with sides between which a hole-cutting tool 15 mounted on a drill string and provided with said device may be disposed. The guide device 14 comprises at least one elongate longitudinally extending hole-side engagement member 20 mounted on a body 19 disposable, in use of the device, in-line with the drill string, so as to be movable relative to said body 19 between a retracted position and a radially outwardly displaced position for hole-side engagement. Each engagement member 20 has pressurised-fluid operable actuator means 24 formed and arranged for driving said hole-side engagement member 20 between its retracted and hole-aide engagement positions. The guide device 14 includes preasurised fluid supply means 28,18 formmed and arranged for controlling the supply of pressurised fluid to the actuator means 28,18 for operation thereof.

Abstract: An earth boring drill bit including replaceable gage pads. The gage pads and the corresponding surface of the earth boring drill bit may include complementary securing elements which mutually engage one another. The gage pad may be removably affixed to the earth boring drill bit by an affixation element, such as a bolt, a mechanical locking element, brazing, welding, mechanical affixation, or another known technique. The invention also includes a method of testing differently configured gage pads employing a single earth boring drill bit, a method of replacing the gage pads of an earth boring drill bit at the drilling site, a method of customizing an earth boring drill bit to include one or more gage pads of desired configuration, and a method of altering the balance or net imbalance of an earth boring drill bit by replacing at least one gage pad thereof.

Abstract: A rotatable steerable drill string in which guidance module controls the direction of the drilling. A magnetorheological fluid in the module supplies pressure to pistons that apply forces to the wall of the bore and thereby alter the direction of the drilling. The pressure applied by the magnetorheological fluid is regulated by valves that apply a magnetic field to the fluid so as to increase or decrease its fluid shear strength thereby controlling the actuation of the pistons and the direction of the drilling.

Abstract: A drilling direction control device, improvements in drilling direction control devices, methods for orienting a rotary driling system, and methods for rotary drilling. The drilling direction control device includes a rotatable drilling shaft, a housing for rotatably supporting a length of the drilling shaft, and a deflection assembly contained within the housing for bending the drilling shaft between a first support location and a second support location. The deflection assembly includes an outer ring which is rotatably supported on a circular inner peripheral surface of the housing and which has a circular inner peripheral surface that is eccentric with respect to the housing. The deflection assembly also includes an inner ring which is rotatably supported on the circular inner peripheral surface of the outer ring and which has a circular inner peripheral surface which engages the drilling shaft and which is eccentric with respect to the circular inner peripheral surface of the outer ring.

Abstract: Apparatus and associated methods are provided which facilitate underbalanced drilling and completion of wells. In a described embodiment of a well control valve, the valve is opened and closed when a drill string is displaced therethrough. A shifting device is carried on a drill bit and deposited in the valve when the drill string enters and opens the valve. The valve is closed and the shifting device is retrieved from the valve when the drill string is tripped out of the well. A packer hydraulic setting tool usable in conjunction with the well control valve in underbalanced completions is also provided.

Abstract: A directional drilling control system for a drill stem carrying a conventional drilling head includes an elongated actuator housing fixed in a borehole being drilled. The drill stem passes through the housing and is generally coaxial with it, and an actuator within the housing is selectively activated to deflect the drill stem with respect to the axis of the housing. The actuator is selectively driven to regulate the direction and amount of deflection to thereby control the direction of drilling. An electrical controller in the housing in communication with a surface controller and/or with feedback sensors in the housing controls the actuator.

Abstract: The drilling assembly includes an eccentric adjustable diameter blade stabilizer having a housing with a fixed stabilizer blade and a pair of adjustable stabilizer blades. The adjustable stabilizer blades are housed within openings in the stabilizer housing and have inclined surfaces which engage ramps on the housing for camming the blades radially upon their movement axially. The adjustable blades are operatively connected to an extender piston on one end for extending the blades and a return spring at the other end for contracting the blades. The eccentric stabilizer also includes one or more flow tubes through which drilling fluids pass that apply a differential pressure across the stabilizer housing to actuate the extender pistons to move the adjustable stabilizer blades axially upstream to their extended position. The eccentric stabilizer is mounted on a bi-center bit which has an eccentric reamer section and a pilot bit.

Abstract: An apparatus for orienting a drilling assembly. In one embodiment the apparatus include a first driveshaft coupled to the drilling assembly, a second driveshaft flexibly coupled at one end to the first driveshaft, and an orientation collar disposed outside the first and second driveshafts so that the first and second driveshafts are freely rotatable within the collar. The is collar substantially coaxial with the first driveshaft and is adapted to maintain a substantially fixed rotary position.

Abstract: The drilling assembly includes an eccentric adjustable diameter blade stabilizer having a housing with a fixed stabilizer blade and a pair of adjustable stabilizer blades. The adjustable stabilizer blades are housed within openings in the stabilizer housing and have inclined surfaces which engage ramps on the housing for camming the blades radially upon their movement axially. The adjustable blades are operatively connected to an extender piston on one end for extending the blades and a return spring at the other end for contracting the blades. The eccentric stabilizer also includes one or more flow tubes through which drilling fluids pass that apply a differential pressure across the stabilizer housing to actuate the extender pistons to move the adjustable stabilizer blades axially upstream to their extended position. The eccentric stabilizer is mounted on a bi-center bit which has an eccentric reamer section and a pilot bit.

Abstract: A pressure activated bendable tool assembly having a longitudinal centerline, the tool assembly comprising an adapter sub for connection to an end of a tubular member having a bore extending longitudinally therethrough and a plurality of bend elements positioned in a serial relationship also having a bore extending longitudinally therethrough, the bore being in fluid communication with the bore of the adapter sub and each adjacent bending element. The bend elements are axially retained by a plurality of retainer sleeves. The retainer sleeves limit the amount the bend elements may be longitudinally displaced from each other about a preselected side of the retainer sleeve element. A head-sub forms a distal end of the tool assembly opposite of the adapter sub.

Abstract: A protective collar for a boring bit which interfaces with a boring head whereby shear forces developed during a boring operation are transmitted through the collar to the boring head, with minimal shear force being carried by mounting bolts. A collar is connected to a boring bit, wherein a head receptacle formed by the collar seatably receives a boring head with substantially close clearance so that shear forces during boring operations are transmitted from, the boring bit to the boring head through the collar. The preferred collar is fabricated from a pipe section, such as for example steel seamless pipe. In one embodiment, a bit recess is cut for interfacing with a boring bit at the head face connection thereof. A head recess is cut opposite the bit recess for providing an exit for the water spray from the nozzle thereof. In another embodiment, the collar has an inclined face with bores alignable with the bores in the boring head when the head is mounted within a receptacle in the collar.

Abstract: A downhole drilling assembly including a housing having an upper end for connection to a drill string and a lower end, a fluid passage extending through the housing from the upper end to the lower end, a power unit contained within the housing, a drive assembly extending within the housing between the power unit and the lower end of the housing such that a mandrel chamber is defined between the drive assembly and the housing, a radially movable stabilizer associated with the housing, and an axially movable mandrel contained within the mandrel chamber, the mandrel being associated with a stabilizer actuator for causing radial movement of the stabilizer in response to axial movement of the mandrel.

Abstract: A coring apparatus permitting the taking of a non-rotating core sample and testing of same, as by NMR, prior to breakage and ejection from the apparatus. A core barrel is suspended from a rotating outer sleeve by one or more bearing assemblies which permit the core barrel to remain stationary during rotation of the sleeve with attached core bit for cutting the core. A core test device is fixed with respect to the core barrel on the outside thereof to test the core as it proceeds through the barrel. The apparatus optionally includes a directional detecting device such as an inclinometer and a compact set of circumferentially-spaced steering arms for changing the direction of the apparatus during coring.

Abstract: Apparatus for curving a vertical borehole laterally towards the horizontal by anchoring a diverter downhole in the bore-hole near the formation to be produced. A special cantaloupe shaped drilling mill is attached to the end of a rigid drill string to form an opening through the casing wall in proximity of the formation to be produced. Then a special concave cutting device enlarges the opening into a window of a size to accommodate a flexible drill string that subsequently is attached to the rigid drill string. A bit attached to the flexible drill string is extended through the window where it drills a curved borehole towards the horizontal and continues laterally through the formation. The flexible drill string has a central fluid passageway and is formed of resilient material which surrounds an inner spring member to form a flexible, longitudinally extending, torque transferring drilling string.

Abstract: A collared boring bit which interfaces with a boring head whereby shear forces developed during a boring operation are transmitted through the collar to the boring head, with minimal shear force being carried by the bolts. A bit collar is welded to a boring bit, wherein a head receptacle formed collectively of the bit collar and the boring bit seatably receives a boring head with substantially close clearance so that shear forces during boring operations are transmitted from the boring bit to the boring head through the bit collar. The preferred bit collar is fabricated from a pipe section, such as for example steel seamless pipe. A bit recess is cut for interfacing with a boring bit at the head face connection thereof. A head recess is cut opposite the bit recess for providing an exit for the water spray from the nozzle thereof.

Abstract: A rotary steerable system for use in a drill string for drilling a deviated well is disclosed. The system utilizes a mechanical gravity reference device comprising an unbalanced weight which may rotate independently of the rotation of the drill string so that its heavy portion is always oriented toward the low side of the wellbore and which has an attached magnet. A magnetic switch that rotates as the drill string rotates is activated when its axis coincides with the axis of the magnet, and this activation results in a thrust member or pad being actuated to "kick" the side of the wellbore.

Abstract: A choke device for controlling fluid flow, particularly in a modulated bias unit, drill bit or other item downhole drilling component, comprises a passage for the flow of fluid, a choke aperture separating an upstream portion of the passage from a downstream portion thereof, and an impingement surface located in the downstream portion of the passage opposite and spaced from the choke aperture, so that fluid flowing through the choke aperture impinges on the impingement surface. The impingement surface is formed from superhard material, such as polycrystalline diamond, and may comprise the front facing table of a two-layer polycrystalline diamond compact of the kind used as cutting elements in drag-type drill bits.

Abstract: A method for steering a drill bit are disclosed that allow steered horizontal drilling to be performed in rocky, semi-hard, or hard soils and rock, including the steps of stopping the advancement and rotation of the drill string, positioning the upper cutting portion so that the upper cutting portion is pointed in the direction it is desired to deflect the drill string, rocking the drill bit in an arc, thrusting the drill string forward while rocking, and rotating the drill bit.

Abstract: An actively controlled rotary steerable drilling system for directional drilling of wells having a tool collar rotated by a drill string during well drilling. A bit shaft has an upper portion within the tool collar and a lower end extending from the collar and supporting a drill bit. The bit shaft is omni-directionally pivotally supported intermediate its upper and lower ends by a universal joint within the collar and is rotatably driven by the collar. To achieve controlled steering of the rotating drill bit, orientation of the bit shaft relative to the tool collar is sensed and the bit shaft is maintained geostationary and selectively axially inclined relative to the tool collar during drill string rotation by rotating it about the universal joint by an offsetting mandrel that is rotated counter to collar rotation and at the same frequency of rotation.

Abstract: A steerable rotary drilling system has a bottom hole assembly which includes, in addition to the drill bit, a modulated bias unit and a control unit, the bias unit comprising a number of hydraulic actuators around the periphery of the unit, each having a movable thrust member which is hydraulically displaceable outwardly for engagement with the formation of the borehole being drilled. Each actuator may be connected, through a control valve, to a source of drilling fluid under pressure and the operation of the valve is controlled by the control unit so as to modulate the fluid pressure supplied to the actuators as the bias unit rotates. If the control valve is operated in synchronism with rotation of the bias unit the thrust members impart a lateral bias to the bias unit, and hence to the drill bit, to control the direction of drilling.

Abstract: An orientation device, particularly for drilling tools, of the kind comprising a first sleeve (1) and a concentrically surrounding second sleeve (2), where in an annulus between the sleeve (1) and the sleeve (2) is disposed an axially displaceable carrier, e.g., in the form of a wedge/key (5) or a rail (8, 9), adapted to slide in an inclined, preferably helical groove (3, 4) disposed in the sleeve (1) or in the sleeve (2), the groove's direction crossing the direction of the carrier's (5; 8, 9) rectilinear movement which, thus, is converted into a relative rotational movement between the sleeve (1) and the sleeve (2). The carrier (5; 8, 9) is adapted to slide in two inclined, preferably helical grooves (3, 4) disposed in the sleeve (1) and the sleeve (2), respectively, and crossing the direction of the carrier's (5; 8, 9) rectilinear movement from opposite side.

Abstract: An apparatus for controlling rotation of an outer sleeve member relative to an inner cylindrical duct member is used in a drilling system for controlling steering of a downhole drilling tool. The apparatus includes an annular swash plate pump and a stack of annular brake disks in the space between the members. The pump is driven by the rotation to pump fluid into a supply cylinder driving the brake. An orifice controls escape of the fluid from the chamber at a controlled rate. The rate is controlled to maintain a balance between the pumping rate and the brake pressure to keep the rotation at a required rate. The apparatus is used in the drilling system which includes a shallow bend in the drilling tool and a system for rotating the bent drilling tool slowly about a longitudinal axis of the drilling tool while the drill bit rotates more rapidly. The controlled orifice further allows the slow rotation to be halted at a predetermined orientation of the bend axis so as to effect a change in drilling direction.

Abstract: An underground directional drilling steering tool for use with a variety of commercially known drill bits which controls the direction of drill while the drill bit is directly powered by the drill string by way of a drill string coupling. The offset transmitter housing retains the tool in a stable orientation downhole by means of the drill string coupling offset orientation in the housing and stabilizing fins affixed to the exterior of the offset transmitter housing. The positioning of the drill bit in relation to the positioning of the offset transmitter housing in the center of the borehole creates a drilling pathway with a constant curvature away from the wide side of the offset transmitter housing. The direction of this curvature is controlled by means of a jaw clutch, which jaw clutch is engaged by drawing back slightly on the drill string thereby retracting the drive shaft and pulling the drill bit coupling within closer proximity to the offset transmitter housing.

Abstract: A steerable directional drilling tool assembly includes a bent housing defining a bend angle and having a mud motor in its upper section and a drill bit below its lower section, an orienting tool rotatably coupled to such upper section and suspended on coiled tubing that extends upward to the surface, an electric motor in the orienting tool operable to rotate the bent housing in either hand direction to change or adjust the tool face angle of the bit, or continuously rotate the bent housing so that the bit drills straight-ahead, and an electric cable extending throughout the coiled tubing to furnish power from the surface to the electric motor and transmit electric signals to and from the surface. A logging tool can be included in the assembly for measuring characteristics of the formation, the borehole, and the tool assembly.

Abstract: A tool for controlling azimuth and/or inclination in a wellbore and methods for utilizing the same is disclosed. The tool generally comprises a freely rotating mandrel, for transmitting drilling forces, contained within two eccentric sleeves. The outer sleeve has an eccentric longitudinal bore that forms a pregnant or weighted side that seeks the low-side of the wellbore. Two gauge inserts or stabilizer shoes are provided on either side of the outer sleeve at ninety degrees to the pregnant housing. The inner sleeve has a further eccentric longitudinal bore that contains the freely rotating mandrel. The mandrel is attached to the drill string at one end and to the drilling bit at the other. The position of the inner sleeve may be controlled, at will from the surface, so that the eccentric is kept to one side of the outer housing, thus transmitting a fulcrum force to the bit and controlling the azimuth and/or inclination of the wellbore.

Abstract: A method for directional boring of all earth formations such as dirt, sand, rock and/or any type combination of formations, utilizing a bit body containing fixed and semi-floating cutting points and one or more fluid channels for the purpose of lubricating and dispersing cut and/or fractured formations.

Abstract: Apparatus for drilling a well comprising, in one embodiment, a borehole assembly having a motor rotated drill head with ports for emitting a fluid, coiled tubing operatively associated with the drill head to supply fluid and support the drill head, the borehole assembly adapted to drill a channel off axis by varying the speed of the motor drive during a cycle or by varying fluid pressure to the drill head during a cycle.

Abstract: A Method and Apparatus for drilling a curved planar borehole, wherein a drill bit is mounted at the lower end of a drill string which extends downwardly into the borehole, and wherein fluid under pressure is pumped through the drill string, a drilling motor for rotating the drill bit, a specialized drill sub mounted in the drill string above the drilling motor, an eccentric sleeve rotatably mounted over the drill sub, an alignment mechanism attached to the eccentric sleeve, a deflection device mounted in the sleeve for bearing against one side of the wellbore, whereby, when fluid under pressure is introduced into the drill sub, the deflection device will move outwardly against the side of the wellbore, the alignment mechanism being such that the drill sub can rotate independently of the eccentric sleeve to prevent reactive torque from the drilling motor from being exerted against the sleeve and the deflection device.

Abstract: In a method for directional drilling with the aid of a drilling device having a drill pipe and a mining tool which moves on an orbit, the tool moves at an essentially constant angular velocity during straight drilling and the angular velocity is periodically changed during curved drilling, in order to thus create a smooth transition from straight drilling to curved drilling and to achieve more precise curve control.