Abstract: A sonde housing for horizontal directional drilling includes a cylindrical housing body with walls defining a longitudinal cavity, a cover for the cavity, and a hold-down means for attaching the cover to the housing body.

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: With a boring machine having a multistrand rod assembly (3) for producing boreholes in the ground, comprising a rotatable inner rod (29), an outer rod (19), at least one steering and digging tool (5; 33, 35, 36) driven by the inner rod and having an axis of rotation (22) inclined at an angle of for example 90.degree. to the axis of the rod (23), and a linear drive for the rod assembly (3, 19, 20), it is possible to perform both straight-ahead boring and, if only the steering and digging tool is driven, curve boring.

Abstract: A propelling apparatus includes a plurality of propellant cylinders series-connected to each other to be propelled by receiving a pushing force from behind, joints for series-connecting the propellant cylinders, a propellant head connected to a forward-most end of the propellant cylinders to be pressed into the earth, a leader member constituting a leading end of the propellant head, the leader member being rotatable about an axis of the propellant head by receiving a driving force from a driving device. An inclined pressure-receiving face is formed at a forward portion of the leader member for receiving an earth pressure in association with the underground propelling movement of the propellant head and steering the propellant head toward the direction of application of the earth pressure to the pressure-receiving face. The joint includes a flexible joint which is pivotally flexible about a transverse axis extending normal to an axis of the propellant cylinder.

Abstract: There is described an improved apparatus for azimuthal orientation of a tool in a wellbore. The apparatus comprises a tubular housing, a mandrel rotatably supported in the tubular housing and extending therefrom for connection to a tool for rotation thereof, a piston mandrel axially aligned with and connected to the mandrel, a piston longitudinally movable in an annulus between the piston mandrel and the tubular housing and being non-rotatable relative to the tubular housing, at least one pin longitudinally movable in concert with the piston arranged to track in respective helical grooves in the mandrel causing rotation of the mandrel in response to longitudinal movement of the pins, and a flow path for selective delivery of pressurized hydraulic fluid to either side of the piston for rotating the mandrel in either the clockwise or counterclockwise directions, or to both sides of the piston equally to maintain the mandrel in a fixed annular orientation.

Abstract: A device for controlling the drilling direction of drills includes a cylinder-type housing 6, a first ring-formed component 11 which is located on an inner peripheral surface that is eccentric with respect to the cylinder-type housing 6, a second ring-formed component 12 which is located on the inner peripheral surface that is eccentric with respect to the circular inner surface of the first ring-formed component 11, and hollow-type harmonized reduction gears 13,14 which rotate the first and second ring-formed components 11,12 relatively around their respective centers. A resolver is positioned between the first and second ring-formed components 11,12 and the hollow-type harmonized reduction gears 13,14 to detect the rotating angular position of the first and second ring-formed components 11,12. A fulcrum bearing 8 of the rotating shaft 2 is located at a midpoint between the drill bit and the first and second ring formed components 11,12.

Abstract: A method and apparatus for penetrating a well casing (12) and surrounding earth strata includes the insertion of a flexible shaft (24) having a ball cutter (22) on an end thereof into upset tubing (18) within a well casing. The upset tubing is provided with an elbow (20) at its lower extremity for receiving the ball cutter therein. The flexible shaft is then rotated and the ball cutter cuts a hole in the well casing and is then moved horizontally a distance, usually less than 12 inches (30.5 cm). The flexible shaft and ball cutter are then removed and a flexible tube (48) having a nozzle blaster (46) on an end thereof is then inserted into the upset tubing in the channel. A fluid of surfactant and water at high pressure is then pumped into the tube wherein the high pressure fluid passes through orifice in the spiral drill thereby cutting an extension into the previously cut channel. The tube is continually fed into the channel as the high pressure fluid continues to blast away the earth's strata.

Abstract: A downhole measurement tool is lowered into a well through a drill pipe. The tool has at least two modules which are joined by a flexible linkage. The linkage has two subs, each of which has an electrical connector for the modules. Each sub has a hub that is threaded. A threaded retainer nut retains each connector. Each nut has a hub that is threaded and is smaller in diameter than the sub hub. A coiled inner spring threadingly engages each nut hub. A coiled outer spring surrounds and threadingly engages each sub hub. The outer spring surrounds the inner spring and is wound in an opposite direction of the inner spring. The springs are embedded within an elastomeric member. The inner spring is dimensioned such that, for a selected lateral bend prior to installation with the outer spring, the inner spring will twist a selected angle in a first twist direction.

Abstract: An earth boring system is disclosed for guiding and steering a string of pipe casings to form an underground cased bore. The string of pipe casings are guided by a boring end assembly including a front casing and a steering head connected at an interface gap by a plurality of hinge assemblies each having an actuator and a pair of connector parts. A protective enclosure protects the hinge assemblies from loosened earth from the earthen bore and from the earth being removed from within the pipe casings. The protective enclosure can be formed by an inner pipe and an outer pipe of both the front casing and the steering head, plus a closure ring and a retainer belt at the interface gap. Guidance sensors are provided to determine the location of the string of pipe casings and a computer control center computes steering head axial and angular displacements for guiding the string of pipe casings and controlling the extent of the interface gap.

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 impact boring head may comprise a main body having an internal cavity with a front end and a rear end. A striker having a head end and a tail end is slidably mounted in the internal cavity of the main body so that the striker can be reciprocated between a forward position and an aft position in response to hydraulic pressure. A compressible gas contained in the internal cavity between the head end of the striker and the front end of the internal cavity returns the striker to the aft position upon removal of the hydraulic pressure.

Abstract: A directional boring apparatus is disclosed where the apparatus is controlled through a method which includes deviating a drill head from a straight path into a desired direction angled away from the straight path. The deviation is achieved by applying an axial force to the drill head when a drill head cutting member is positioned within an arc of rotation through which the desired direction passes. The drill head is retracted when the cutting member is outside of the arc of rotation.

Abstract: A drilling assembly for drilling holes in subsurface formations comprises a drill bit 10, a drive unit 12 including a housing and a rotor 11 operatively coupled to the drill bit to rotate the drill bit relative to the housing, and a modulated bias unit 14 coupled to rotate with the drive unit housing and apply a lateral bias thereto in synchronism with rotation of the housing. The modulated bias unit 14 comprises one or more hydraulic actuators including members 16 which, in use, bear against the sides of the borehole, and means for modulating the pressure of fluid supplied to the actuators in synchronism with rotation of a component of the drilling assembly, and in selected angular phase relation thereto, whereby each hydraulic actuator is actuated in a selected rotational position of the component.

Abstract: A flex joint is disclosed for connecting two cylindrical instrument housings of a downhole instrument assembly that will bend as required to allow the instrument housings to move through a curved section of a well bore. The joint includes spaced tubular connectors for connecting the joint to the cylindrical housings. The connectors are connected by a flexible cable or thin walled cylindrical tube. One or more helical springs extend between the connectors and are held in compression to urge the connectors toward an in-line position while allowing the joint to bend as required for the cylindrical instrument housings to travel through a curved section of a well bore.

Abstract: A subterranean drilling assembly for linear and nonlinear drilling. A downhole motor-based bottomhole assembly with a bit deflection device includes a torque compensation device and is secured to the drill string via a swivel assembly to permit independent rotation of the string and the bottomhole assembly. In the case of a drill pipe string, the string may be rotated continuously during both linear and nonlinear drilling to reduce drag. In the case of a tubing string, the bottomhole assembly is rotated by the torque compensation device during straight drilling. In both cases, the torque compensation device is employed to adjust TFO for nonlinear drilling when the bottomhole assembly is not rotated. In an alternative embodiment, a torque-sensitive clutch is employed in lieu of the torque compensation device to provide rotational orientation to, and rotation of, the bottomhole assembly.

Abstract: A modulated bias unit, for use in a steerable rotary drilling system, comprises a number of hydraulic actuators spaced apart 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, and a control valve operable to bring the actuators alternately in succession into and out of communication with a source of fluid under pressure, as the bias unit rotates. The fluid pressure supplied to each actuator may thus be modulated in synchronism with rotation of the drill bit, and in selected phase relation thereto, so that each movable thrust member is displaced outwardly at the same rotational position of the bias unit so as to apply a lateral bias to the unit for the purposes of steering an associated drill bit.

Abstract: A ram boring apparatus has a generally cylindrical body with an attached head, the apparatus being connected to a drive rod which pushes the apparatus forwardly through the earth. The drive rod can also rotate the body and the attached head about the longitudinal axis of the apparatus, and operation of the apparatus can also be supported by the ejection of pressure fluid from one or more jets arranged on the head and by a hammering mechanism carried by a portion of the body. The hammering mechanism is activatable by pressure fluid from the same source as the pressure fluid supplied to the one or more jets. The pressure fluid is delivered through the hollow drive rod and a control valve in a fluid supply line in the body, in dependence on the pressure of the pressure fluid supplied to the apparatus, selectively directs the pressure fluid to the one or more jets in the head or simultaneously to both the one or more jets and to the hammering mechanism.

Abstract: A system for controlling the rotation of a roll stabilizable control unit in a steerable rotary drilling assembly comprises an instrument carrier rotatably mounted on a support connected to the drill string. A first rotatable impeller is mounted for rotation by a flow of drilling fluid over the impeller and is coupled to the instrument carrier so as to transmit a torque to it. Sensors carried by the instrument carrier sense the rotational orientation of the instrument carrier and produce a control signal indicative of its rotational orientation, and the torque applied to the instrument carrier by the impeller is controlled, at least partly in response to said signal, so that the instrument carrier can, for example, be roll stabilized if required. A second rotatable impeller is coupled to the instrument carrier for transmitting to it a second torque, which may also be controlled, in the opposite direction to the torque transmitted by the first impeller.

Abstract: The invention provides a method for reversing an impact boring tool of the type having a reversing mechanism actuated by rotation of the compressed air supply hose that enters the tool through a rear end opening. This method includes the initial step of connecting the air supply hose to the tool using a quick-release coupling device including tubular male and female members which are coupled together, one of the members being mounted on the end of the air supply hose and the other mounted on an air inlet conduit of the tool, the coupling device further having a locking sleeve and a ball seated in a first pit in one of the members and configured for insertion into a second pit in the other of the members as the locking sleeve moves over the ball, the locking sleeve being biased to a locked position wherein the ball is seated in both pits thereby preventing rotation of one member relative to the other as well as disengagement of one member from the other.

Abstract: A steerable rotary drilling system comprises a bottom hole assembly which includes, in addition to a drill bit, a modulated bias unit and a control unit including an instrument carrier which is rotatable relative to the bias unit. The bias unit comprises a number of hydraulic actuators spaced apart around the periphery of the unit, each having a movable thrust member which is displaceable outwardly for engagement with the formation. Each actuator can be connected, through a rotatable control valve, to a source of drilling fluid under pressure, the control valve comprising a first part, rotatable with the instrument carrier, which cooperates with a second part which is rotatable with the bias unit. Means are provided to roll stabilize the instrument carrier so that relative rotation between the bias unit and instrument carrier, as the bias unit rotates, causes the valve to operate the actuators in synchronism with rotation of the bias unit so as to apply a lateral bias thereto.

Abstract: A modulated bias unit, for controlling the direction of drilling of a rotary drill bit when drilling boreholes in subsurface formations, comprises a number of hydraulic actuators spaced apart around the periphery of the unit. Each actuator comprises a movable thrust member which is hydraulically displaceable outwardly and a pivotally mounted formation-engaging pad which overlies the thrust member. An inlet passage supplies fluid under pressure to the chamber, and an outlet passage delivers fluid from the chamber to a lower pressure zone. A selector control valve modulates the fluid pressure supplied to each actuator in synchronism with rotation of the drill bit so that, as the drill bit rotates, each pad is displaced outwardly at the same selected rotational position so as to bias the drill bit laterally and thus control the direction of drilling.

Abstract: A drill string orienting tool for insertion into a well bore includes a housing that has a plurality of inwardly projecting splines. A mandrel is disposed within the housing. The orienting tool has two operating positions, a running position, and an orienting position. The housing is longitudinally moveable relative to the mandrel between the running position and the orienting position. The mandrel and the housing define an annular chamber that is vented to the exterior of the housing. A flexible metallic coiled tube is disposed within the annular chamber and contains hydraulic fluid. The upper end of the coiled tube is coupled to the housing and is in fluid communication with the first fluid chamber. The lower end of the coiled tube is coupled to the mandrel. The mandrel has outwardly projecting splines that are engageable with a corresponding set of inwardly projecting splines on the housing when the orienting tool is in the running position. A piston is movably disposed within the housing.

Abstract: A downhole sub for use in directional drilling with a bent sub attached to a drill bit. The drill bit is operated by a downhole motor. The downhole sub includes upper and lower tubular sections whose centers are offset from one another in the bend direction of the bent sub. The downhole sub includes an intermediate tubular section disposed between the upper and lower tubular sections, with the bore of the intermediate section included within overlap between extensions of each of the bores of the upper and lower tubular sections. The axes of the upper and lower tubular section are parallel and offset between about 1/4 inch and 2 inches. The intermediate section grades gradually into the upper and lower tubular sections. The downhole sub is used by incorporation into a drill string above the bent sub and spaced from the bend sufficiently to allow the drill string to use the downhole sub as a lever to force the drill bit into the wall of the borehole.

Abstract: A rotatable pressure seal between a relatively rotatable shaft and body structure comprises two annular sealing discs concentric with the shaft, one disc being mounted on the body structure and the other disc being carried on the shaft the discs having engaging sealing faces formed of polycrystalline diamond or other superhard material. The pressure seal is particularly for use in a modulated bias unit, for controlling the direction of drilling of a rotary drill bit when drilling boreholes in subsurface formations. The bias unit comprises a number of hydraulic actuators spaced apart around the periphery of the unit, and a selector control valve modulates the fluid pressure supplied to each actuator in synchronism with rotation of the drill bit so that, as the drill bit rotates, a thrust member of each actuator is displaced outwardly at the same selected rotational position so as to bias the drill bit laterally and thus control the direction of drilling.

Abstract: A modulated bias unit, for controlling the direction of drilling of a rotary drill bit when drilling boreholes in subsurface formations, comprises a number of hydraulic actuators spaced apart around the periphery of the unit. Each actuator comprises a movable thrust member which is hydraulically displaceable outwardly and a formation-engaging pad which overlies the thrust member and is mounted on the body structure for pivotal movement about a pivot axis located to one side of the thrust member. A selector control valve modulates the fluid pressure supplied to each actuator in synchronism with rotation of the drill bit so that, as the drill bit rotates, each pad is displaced outwardly at the same selected rotational position so as to bias the drill bit laterally and thus control the direction of drilling. The pivot axis of the formation-engaging member is inclined to the longitudinal axis of rotation of the bias unit so as to compensate for tilting of the bias unit in the borehole during operation.

Abstract: A modulated bias unit is provided for controlling the direction of drilling of a rotary drill bit when drilling boreholes in subsurface formations. The unit comprises a plurality of hydraulic actuators spaced apart around the periphery of the unit and having movable thrust members hydraulically displaceable outwardly for engagement with the formation of the borehole being drilled. Each actuator has an inlet passage for connection to a source of drilling fluid under pressure and an outlet passage for communication with the annulus. A selector control valve connects the inlet passages in succession to the source of fluid under pressure, as the unit rotates, and a choke is provided to create a pressure drop between the source of fluid under pressure and the selector valve. A further choke is provided in the outlet passage from each actuator unit. The actuators and control valve arrangements may take a number of different forms.

Abstract: A modulated bias unit, for controlling the direction of drilling of a rotary drill bit when drilling boreholes in subsurface formations, comprises a number of hydraulic actuators spaced apart around the periphery of the unit. Each actuator comprises a movable thrust member which is hydraulically displaceable outwardly and a pivotally mounted formation-engaging pad which overlies the thrust member. An inlet passage supplies fluid under pressure to the chamber, and an outlet passage delivers fluid from the chamber to a lower pressure zone. A selector control valve modulates the fluid pressure supplied to each actuator in synchronism with rotation of the drill bit so that, as the drill bit rotates, each pad is displaced outwardly at the same selected rotational position so as to bias the drill bit laterally and thus control the direction of drilling.

Abstract: An apparatus for drilling curved sections of well holes is described which includes a first tubular member having a bulbous first end, a second end, an exterior surface and an interior surface defining an interior bore. A plurality of pockets form a first annular ring in the exterior surface at the bulbous first end of the first tubular member. A second tubular member is provided having a first end, a second end, an exterior surface and an interior surface defining an interior bore. A socket is formed to accommodate the bulbous first end of the first tubular member at the second end of the second tubular member. The first end of the first tubular member extends into the interior bore of the second tubular member until the bulbous first end engages the socket. The bulbous first end of the first tubular member is capable of omnidirectional pivotal movement within the socket.

Abstract: In a curve drilling assembly having a mandrel rotatably mounted within a cylindrical sleeve, an apparatus and method of using the apparatus are disclosed for orienting the sleeve of a curve drilling system and for shifting modes of operation of a curve drilling system from a steering mode to a straight drilling mode. The apparatus comprises: a drilling fluid powered blade that is carried by the sleeve for engaging the walls of a curved borehole and inducing counter-clockwise rotation of the sleeve; and a valve, carried within the mandrel, for operating the blade by introducing pressurized drilling fluid from the interior of a drill string connected to the mandrel.

Abstract: Apparatus for steering a drill bit at the end of a drill string within the borehole to selectively effect drilling along either a curved path or a substantially straight path comprises a first downhole motor assembly coupled to the drill bit and operable to rotate the drill bit to effect drilling, the assembly being arranged to angularly tilt the rotational axis of the drill bit relative to the axis of the section of the borehole being drilled, and a second downhole motor coupled to the first motor assembly to the drill string and operable to rotate the first motor assembly.

Abstract: A connector for drill string elements is formed as a cylindrical body having a bore and threaded sections on opposite ends for connecting drill tubing or pipes together. A plurality of bearings are secured at spaced points to the exterior of the cylindrical body. One or more slots are formed in the exterior of the body to allow fluid to pass in a return flow. Also disclosed is a helical stack-out inhibiting system for horizontal drilling operations utilizing a plurality of tubular members having an outer diameter that is slightly less than the inner diameter of the hole being drilled. A plurality of rolling bearing members are secured to and extend outboard of the exterior surface of each tubular member. The rolling bearing members facilitate the axial and rotational movement of the drill string in horizontal drilling operations and also inhibit the drill pipe or tubing from contacting the sides of the hole.

Abstract: An articulated directional drilling tool assembly for use in drilling a borehole having a short radius of curvature includes a mud motor whose housing is pivotally connected to a lower housing having upper and lower sections that are joined together in a manner to define a bend angle. The lower housing section carries a full gage stabilizer that centers its lower end in the borehole. The upper housing section carries pads which are forced against the low side of the borehole by a hydraulic piston to increase the side loading on the bit below the lower housing section and cause it to drill a sharply curving borehole. The motor housing is connected to the lower housing by an articulative, torque transmitting coupling, and the motor housing is connected to an orientation measuring sub thereabove in the same manner.

Abstract: A modulated bias unit, for controlling the direction of drilling of a rotary drill bit when drilling boreholes in subsurface formations, comprises a number of hydraulic actuators spaced apart 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. A selector control valve modulates the fluid pressure supplied to each actuator in synchronism with rotation of the drill bit so that, as the drill bit rotates, each movable thrust member is displaced outwardly at the same selected rotational position so as to bias the drill bit laterally and thus control the direction of drilling. The control valve is a disc valve comprising two relatively rotating elements having contiguous surfaces formed of polycrystalline diamond.

Abstract: An apparatus for boring a continuous underground tunnel and located inside f the forward end of a continuously rotating, pushed drillstring includes a housing for receiving pressurized drilling fluid, a nozzle including bores, attached forwardly to the housing for discharging the pressurized drilling fluid from the nozzle, a rotatable valve located in said housing for receiving and forwardly directing pressurized drilling fluid from the housing to the nozzle. The valve may be rotated in a 1st position, thereby directing the pressurized drilling fluid to a first set of bores in the nozzle for boring straight ahead. The valve may also be rotated in a 2nd position, thereby directing the pressurized drilling fluid to a second set of bores. By maintaining the valve in the 1st position for 1/4 rotation of each revolution of the drillstring and then maintaining the valve in the 2nd position for the remaining 3/4 rotation of each revolution of the drillstring, an off axis (curved) tunnel may be bored.

Abstract: There is described a downhole stabilizer (10) for use in a drill string adjacent the drill bit. The stabilizer (10) includes a hollow and generally cylindrical casing (12) the outer surface of which defines three angularly spaced protrusions (24, 26, 28), the radially outer surfaces of which define a diameter which is marginally less than the diameter of the bore to be drilled. Two of the protrusions (24, 26) carry radially extensible and retractable spacer members (42-52) which are interconnected so that radially outward movement of one member (42-46) results in radially inward movement of the other member (48-52) and vice versa, effectively to vary the radial length of the respective protrusions. A control mandrel (56) is mounted within the casing (12) and is selectively movable between first and second positions.

Abstract: In an earth boring device with a boring head (14) rotatable about its axis (16), which boring head for the control of its direction has a control surface (18) inclined to its axis (16) and at least one jet (20) for the discharge of a pressurized boring fluid, with the jet openings being arranged on a side of the boring head parallel to the axis of the boring head and facing away from the control surface (18), the axial spacing of the jets from the boring head tip and their stream direction are so chosen that in the use of the boring head the streams escaping from the jets reach essentially only the region of earth lying to the side of the boring head.

Abstract: A boring apparatus (10) is disclosed which includes a casing (16) mounting a drill bit (42) and a deflection shoe (22). The cutting circle of the drill bit is offset from the centerline axis (18) of the casing (16). At least a portion of the deflection shoe (22) lies outside the cutting circle of the drill bit so that the deflection shoe causes the boring apparatus to deflect as the borehole is drilled. Rotation of the casing 16 a predetermined distance will cause the boring apparatus to change the direction of deflection. A continuous rotation of the casing will permit the boring apparatus to bore straight ahead. The drill stem (32, 68, 74) rotating the drill bit can be mounted concentric with the centerline axis of the casing and offset therefrom, at an angle relative to the centerline axis and can be sufficiently flexible to be curved to accommodate the signal beacon housing.

Abstract: A drilling system for controlling steering of a downhole drilling tool 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 system 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. The system for rotating and halting this slow rotation comprises a downhole swivel coupling between the drilling tool and the drill string so that torque from the drill bit tends to rotate the drilling tool in the opposite direction. A control device is provided to restrict the amount of torque communicated through the swivel coupling and to halt the swivel coupling as required to control the steering of the drill bit.

Abstract: A steerable rotary drilling tool includes a drill bit mounted on the lower end of a housing by a drive shaft having an articulative coupling that allows the bit's rotation axis to be inclined relative to the rotation axis of the housing, an eccentric weight in the housing that maintains the bit axis pointed in only one direction in space as the bit is turned by the housing, and a clutch system that allows such direction to be changed downhole. A measuring-while-drilling tool is included to allow the progress of the drilling to be monitored at the surface, and to allow changing the bit axis or toolface by a selected amount.

Abstract: A fluid powered stepping motor is disclosed for connecting to a pipe string to rotate a tool relative to the pipe string by raising and lowering the pressure in the pipe string. The motor includes a housing, the lower end of which is connected to the tool. A mandrel is connected to the pipe string and extends into the upper end of the housing to support the housing for rotation relative to the mandrel. A passageway extends longitudinally through the mandrel in fluid communication with the pipe string. A piston is located in and closes the passageway so that the piston will move downwardly in the passageway in response to fluid pressure in the passageway acting on the piston. Resilient spring resists the downward movement of the piston in the passageway, and cam members rotate the housing an incremental distance when the piston moves downwardly in the passageway.

Abstract: A pump pumps a drive fluid through a drill string and drill head during drilling. A movable element is mounted in the drill head for effecting a lateral movement on the drill head when moved in response to the pressure of the drive fluid in the drill head. This is in the form of pistons that are extended outwardly sideways from the drill head against the side of the borehole or an asymmetrical drill bit that applies a lateral force when a longitudinal force is applied to it. Steering is achieved by applying the lateral force when the drill head is in a selected rotational position. An indication is provided at the out-of-ground end of the drill string of the orientation of the drill head during rotation. A manually or automatically operated apparatus applies an impulse of force to the drive fluid at the out-of-ground end of the drill string when the drill head is at the selected orientation. This produces an impulse of increased pressure to the element in the drill head while the drill string is rotating.

Abstract: Directional drilling is achieved by a weight-on-bit control mechanism that is attached to a drill bit having asymmetrical cutters. A valve in the mechanism temporarily interrupts or bypasses mud flow toward the bit to correspondingly change the downward force acting thereon during a portion of each revolution. The bit will drill preferentially on that side of the bottom surface of the borehole where the downward force is increased, and thereby cause the borehole to curve in an azimuthal direction on such side.

Abstract: A scoophead/diverter system is run into a wellbore using a novel scoophead running tool. The running tool allows circulation through its inside diameter, and has internal pressure integrity to test any seals below the running tool prior to releasing the scoophead. This also allows circulation while running in order to apply MWD techniques. This run-in tool includes a mounting head from which extends a running stump and a housing (or connecting mandrel) parallel to the running stump. The running stump and housing are sized and configured to be respectively received in large and small diameter bores in the scoophead. The scoophead running tool thus allows torque to be transmitted about the centerline of the scoophead assembly in spite of being attached into one of the offset bore. This torque transmission is accomplished by connecting the connecting mandrel between the running tool and scoophead at the same offset as the large bore of the scoophead.

Abstract: Methods and apparatus combinations for making a substantially horizontal water well completion for irrigation or commercial water supply purposes includes running a substantially vertical surface string of casing, running a bend section of casing that has been preformed to provide a bend angle of about 90.degree. in a straightened-out condition down through the surface section and allowing it to assume its bend condition below the lower end of the surface section, coupling the upper end of the bend section to the lower end of the surface section, running a water production section of casing through both the surface and bend sections and outward horizontally into the aquifer, and either coupling the inner end thereof to the outer end of the bend section, or extending the production section all the way to the surface. Unique coupling mechanisms, running and retrieving tools and other devices also are disclosed.

Abstract: A device for remotely operating equipment through a variation in the flow of a fluid includes a coupling unit connecting the device and the equipment to be operated, an assembly of two elements cooperating with one another to control an opening value of a channel through which the fluid flows and a control assembly for adjusting the opening value in order to have it take on one or the other of two particular values.

Abstract: A horizontal earth boring machine which is capable of transferring drill cuttings from the boring area back through the machine to allow for more efficient boring through both hard and soft rock strata is disclosed. The earth boring machine has an air powered hammer bit drill with air passageways therethrough for flushing the boring area and also has a rotary drive for use in rotating augers secured inside a casing for transporting the drill cuttings back through the casing and out an air diverter discharge near the front of the machine. The machine is capable of movement along a track so as to facilitate the boring operation.

Abstract: The present invention relates to a positioning device capable of positioning a member in any direction with a high degree of resolution by using a hollow type harmonic drive mechanism, and to a drilling-direction control device for a drilling system utilizing the positioning device. The device of the present invention is mainly constituted by a double eccentric mechanism section (10). A first annular member (12) is rotatably supported by a circular inner circumferential surface (11a) of the cylindrical member (11) of this mechanism section, and a second annular member (13) is rotatably supported by a circular inner circumferential surface (11b) of the first annular member.

Abstract: Boring apparatus for forming a generally horizontal underground passage in soil for a utility conduit or the like that includes a tool head with a base portion and a nose portion mounted on the base portion. The base portion is rotatable relative to the nose portion between a first position in which nose portion surfaces are symmetrical with respect to the tool axis so that the tool will move along a straight path and a second position in which nose portion surfaces are in asymmetrical position with respect to the tool axis so that said tool will move along a curved path. By application of torque to the base portion, the base portion is shifted relative to the nose portion to shift the tool head from between an asymmetrical configuration and symmetrical configuration. Torque generating surface structure interacts with the soil and generates clockwise torque in one tool head position and counter clockwise torque in the other tool head position.

Abstract: An improved method and apparatus for controlling the direction of advance of a rotary drill to produce a borehole profile substantially as preplanned with minimal curvature while maintaining optimum drilling performance. The preferred embodiment of the system comprises a drill string, a rotatable drill bit carried on said drill string, and a compliant subassembly in said drill string, said compliant subassembly facilitating changes in the direction of drilling of said borehole. The system further comprises a plurality of sensors for measuring strains within the compliant subassembly and for producing data signals corresponding to the strain measurements. A control system is operable to use the data signals to change the direction of the borehole by applying a shear force to the drill bit.

Abstract: A down hole well tool shown in the form of an orienting tool (OT) has mandrel (16) with helical grooves (16a) thereon and a tubular member (20) which telescopically receives the mandrel (16). Keys (22) on tubular member (22) engage in the grooves (16a). Mandrel (16) is connected with non rotatable coil tubing (T) and member (20) is connected to a bottom hole assembly (BHA) which may comprise a plurality of components or a single device to form a well tool. The orienting or rotating tool (OT) and down hole assembly (BHA) constitute an orienting assembly, for orienting or rotating a device such as a drill bit (13) to drill a deviated well bore, including a horizontal well bore, to a desired target area. Downhole instruments relay to the surface equipment (1) the azimuth, inclination and tool face of the directional drilling equipment.