Abstract: The device contemplated provides a method for positioning the drill bit in a drilling operation to achieve small changes in hole angle or azimuth as drilling proceeds. Two different positions are available to the operator. The first is a straight ahead position where the tool essentially becomes a packed hole stabilizer assembly. The second position tilts the bit across a rotating fulcrum to give a calculated offset at the bit-formation interface. The direction that the bit offset is applied in relation to current hole direction is controlled by positioning the orienting pistons prior to each drilling cycle, through the use of current measurement-while-drilling (MWD) technology. Components of the tool comprise a MWD housing, upper steering and drive mandrel, non-rotating position housing, lower drive mandrel splined with the upper mandrel, rotating fulcrum stabilizer and drill bit.

Abstract: Apparatus for boring a hole from an inside of a tube outwardly perpendicular to a longitudinal axis of the tube comprises a drill shoe having a longitudinal axis and being positionable in the tube, the shoe having an inlet, an outlet perpendicular to the shoe longitudinal axis and a passageway connecting the inlet and outlet, a torsional load transmitting element having no torsional flexibility in relation to its bending flexibility, having a longitudinal axis and being disposed in the passageway, the torsional load transmitting element being movable relative to itself with no resistance about first and second perpendicular axes both of which are perpendicular to the longitudinal axis of the torsional load transmitting element, a hole saw connected to one end of the torsional load transmitting element and a motor rotatably connected to the other end of the torsional load transmitting element.

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 first stabilizer associated with the housing and located between the power unit and the lower end of the housing, an axially movable mandrel contained within the mandrel chamber, the mandrel being associated with a stabilizer actuator for causing radial movement of the first stabilizer in response to axial movement of the mandrel, and a sensor apparatus located between the power unit and the lower end of the housing for sensing at least one drilling parameter.

Abstract: Directional drilling apparatus (26) for location on a drill string (20) comprises a stabiliser (32) having a mandrel (38) for connection to the drill string (20) and an eccentric non-rotating element (46) mounted on the mandrel (38) for offsetting the string (20) in the bore (22) and a non-rotating offset mass (34) for maintaining the element (46) at a selected orientation relative to the bore (22) as the drill string (20) rotates.

Abstract: Directional drilling apparatus (26) for location on a drill string (20) comprises a stabilizer (32) having a mandrel (38) for connection to the drill string (20) and an eccentric non-rotating element (46) mounted on the mandrel (38) for offsetting the string (20) in the bore (22) and a non-rotating offset mass (34) for maintaining the element (46) at a selected orientation relative to the bore (22) as the drill string (20) rotates.

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 mining machine (20) inclu ding a launch vehicle (11) which drives an auger flight (21). The extremity of the Auger flight (21) is a cutter head (22). An inert gas is delivered to adjacent the cutter head (22) by a tube (50). The cutter head (22) is also provided with a ground penetrating radar antenna (42) as well as a microwave transmitting/receiving device (47) which transmits and receives microwave signals for the purposes of controlling the cutter head (22) and transmitting information gathered by means of the antenna (42).

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: The present invention provides a drilling assembly with a stabilization system that stabilizes at least a section of the drilling assembly as a function of one or more downhole measured parameters or parameters of interest. One or more sensors carried by the drilling assembly measure the desired parameters of interest and a control system controls the stabilizer system in response to one or more determined parameters of interest to provide desired stabilization of a section of the drilling assembly. Measurement-while-drilling sensors whose measurements are affected by the parameters of interest are preferably disposed in the stabilized section. In one embodiment, the stabilization system includes at least two axially spaced apart stabilizers. Each such stabilizer includes a plurality of independently adjustable members that radially extend from the drilling assembly to exert force on the wellbore inside.

Abstract: A Measurement-while-Drilling method and apparatus for obtaining information about a formation uses sensors on substantially non-rotating pads attached to a rotating housing that is part of the drilling assembly. The pads make contact with the formation. The sensors may be density, NMR, resistivity, sonic or electromagnetic. The NMR sensors may use a static magnetic field that can be either radial or longitudinal in direction. The resistivity sensors may involve direct measurement of leakage current or may rely on induction methods. The sonic sensors may be three component transmitters and/or receivers for determining compressional and shear velocities of the formation and may also be used to image the formation in a VSP or a reverse VSP. In an alternate arrangement, the sensors rotate with the drill bit. A downhole microprocessor analyzes the data to improve signal-to-noise ratio and to reduce redundancy in the acquired data.

Abstract: A downhole drill system comprising a drill string, a drill bit terminating the drill string, a bent sub in the drill string above the drill bit, a motor housing in the drill string above the drill bit and a downhole sub connected within the drill string to the motor housing. The downhole sub comprises an adaptor housing in the drill string above the motor housing, a mandrel connected to the adaptor housing, the mandrel having a shoulder facing the adaptor housing, the mandrel shoulder and the adaptor housing together forming an annular recess, a kick pad mounted for rotation in the annular recess and movable around the annular recess when the mandrel is disengaged from the adaptor housing and a lock mechanism for locking the kick pad in a fixed position relative to the adaptor housing when the mandrel is engaged with the adaptor housing.

Abstract: The present invention is an apparatus for use in drilling operations. It uses an under-reamer having a plurality of elongated arms with cutting elements at the ends of the arms for enlarging a previously drilled borehole drilled by a drill bit. One or more stabilizers in close proximity to the under-reamer provide stability to the under-reamer and the drill bit. The stabilizer could be rotating or non-rotating; and could be positioned between the under-reamer and the drill bit, or above the under reamer or above a directional device on the drillstring. The cutting arms are selectively operable to perform the enlargement. The stabilizer may be provided with members that closely fit the size of the borehole.

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: An integrally formed, solid casing centralizer for centering casing strings in oil and gas wells. The casing centralizer includes a central body having a bore adapted to closely engage a casing string and a plurality of integral blades radiating outwardly from the central body. The centralizer is formed by heating a billet of suitable metal to a temperature sufficient to render the billet malleable for extrusion yet which is substantially below a melting temperature of the billet, forcing the metal through a die, thereby forming a workpiece having a profile suitable to form a desired cross-sectional shape of a casing centralizer; cooling the extruded workpiece, and cutting the cooled, extruded workpiece into sections, each section having a length sufficient to form a casing centralizer.

Abstract: A drillstring carries a stabilizer sub above the drill bit for steering or directing drilling. The stabilizer body is rotatably carried by the stabilizer sub, wherein the stabilizer body remains substantially stationary relative to the borehole as the drillstring rotates. At least one stabilizer blade is carried by the stabilizer body, the stabilizer blade being radially extendable from the stabilizer body and into engagement with the sidewall of the borehole. Each stabilizer blade is extendable and retractable from the stabilizer body independently of the others. The stabilizer blades are coupled to the stabilizer body such that the blades are capable of collapse to minimum radial extension if the stabilizer assembly becomes stuck in the borehole.

Abstract: A stabilizer body is rotatably carried by the stabilizer sub, wherein the stabilizer body remains substantially stationary relative to the borehole as the drillstring rotates. At least one stabilizer blade is carried by the stabilizer body, the stabilizer blade being radially extendable from the stabilizer body and into engagement with the sidewall of the borehole. Each stabilizer blade is extendable and retractable from the stabilizer body independently of the others.

Abstract: A rock drill guide tool comprises a sleeve arrangement (8) placed around a tubular drill tube (9) which rotates during a drilling operation and through which drilling liquid is supplied under pressure during drilling intervals. The sleeve arrangement includes a plurality of support units (15, 16) which can be projected out into contact with the wall of a drill hole and which are placed circularly in the sleeve arrangement. The support units (15, 16) are placed in at least two ring sections of the sleeve arrangement and are provided with elements (19, 20) which project out against the wall of a drill hole. These elements engage the rock so as to cut grooves into the wall of a drill hole as the drill is moved down during a drilling operation.

Abstract: An articulated directional drilling tool assembly for use in drilling a borehole having a short radius of curvature includes a mud motor having an upper housing that is pivotally connected to a lower housing having upper and lower sections. Such sections are joined together in a manner to define a bend angle. The drill bit box carries a stabilizer that centers it in the borehole. The upper housing section carries an eccentric stabilizer assembly which tilts it toward the low side of the borehole to increase the effectiveness of the bend angle. A hydraulic piston also can be used to increase the side loading on the bit and cause it to drill a sharply curving borehole. The upper housing of the motor is connected to the lower housing by an articulative, torque transmitting coupling, and the upper motor housing is connected to an orientation measuring sub thereabove in the same manner.

Abstract: A tubing friction reducer is mounted on a length of tubing within a bore hole. The friction reducer includes a cylindrical body having a first section and a second section hingedly secured around an exterior surface of the coiled tubing, the cylindrical body having an outside diameter larger than an outside diameter of the coiled tubing and less than an inside diameter of an adjacent bore surface. A plurality of roller bearings positioned on and extending outwardly from the cylindrical body extending in a generally axial direction along the cylindrical body for the purpose of reducing friction between the coiled tubing and the bore surface generated upon contact between the coiled tubing and the bore surface. Retaining mechanisms such as collapsible springs are included for securing the roller bearings to the cylindrical body. The tubing friction reducers are placed along the tubing at intervals to either minimize injector force, prevent buckling, and tubing failure, due to buckling or wear.

Abstract: A centralizing tool for use in drilling an earth borehole. Drilling fluid pressure extends contact members radially from the tool into engagement with the borehole walls. A timing wheel engages each of the contact members to coordinate their radial movement. A fluid driven tubular central piston extending through the timing wheel causes the wheel to rotate as the piston is moved axially through the tool. High fluid pressure drives the contact members radially outwardly and moves the piston axially to compress a central coil spring surrounding the piston. Reduction of the drilling fluid pressure allows the spring force to return the piston to its initial axial position which rotates the timing wheel to retract the contact elements.

Abstract: A downhole tool connectable to a drill string by a connection atop the tool includes a mandrel for connection with the drill string, the mandrel being rotatable within a body. A plurality of blades are individually extendible radially from the body to engage the wall of a well bore, the radial position of the blades being adjustable between a first retracted position and a second extended position to position the centre line of the mandrel at a desired position relative to the longitudinal axis of the well bore. A positioning system is provided to hold each of the blades at the retracted position, the extended position or at any intermediate position therebetween.

Abstract: A drill bit for drilling subterranean formations includes a device to provide a "universal" effect between the shank and crown for self alignment of the crown with the bore hole in the formation. The bit is suitable for down-hole assemblies configured for straight drilling, directional drilling and navigational drilling. The device can be incorporated into both drag bits and roller-type "rock" bits. Preferred embodiments include a flexible sub connecting the crown to the shank portion and having reduced stiffness relative to the drill string. Alternatively, a spherical universal joint or trunnion type universal is used. Replaceable lugs increase durability and reliability of the universal. The device equalizes the loads on cutters while reducing wear, average loads, and impact loads on cutters. Bore hole diameter and chatter of the bit in the bore hole are reduced, promoting maximum efficiency and rate of penetration as wobble and precession are minimized.

Abstract: Control structure for extending and retracting at least two stabilizing arms (2) in a drill or core device, in particular stabilizing arms (2) in a drill or core bit (3), each arm (2) having an extremity pivoted around an axis (6) parallel to the axis (4) of the drill bit, comprising, per arm (2), a piston (8) provided for pivoting the arm (2) around said axis (6) so that it takes the arm to two extreme positions, a first position wherein it is housed in the bit (3) and a second position wherein it projects with respect to this bit. The control structure (10) and synchronization means (11) are provided respectively for displacing the pistons (8) under the influence of the drill fluid and for making the pistons (8) act substantially simultaneously in the same direction and to the same amplitude.

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 drill bit box carries a stabilizer that centers it 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 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: 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: 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 stabilization device for a down-hole motor for use in drilling operations for example in oil-fields to control any tendency for spiralling of the tool bit during the drilling action and to permit steering by a "orientate and rotate" technique. In an example of the device, an end portion of a motor shaft (26) projects from a motor body (20), the projecting portion being comprised of an attachment apparatus or bit box (28) by which a tool bit (38) is connected for rotation. The bit box (28) may be separable from the shaft (26) or may be integrally formed therewith, but, is provided with a stabiliser means (32) in the form of part-helical vanes surrounding the bit box (28). The bit (38), when secured in the box (28), is located immediately adjacent the stabilising vanes (32) for maximum control; additionally, stabiliser vanes (22,24) may be provided on the motor body portion (20) and, if required, on the selected tool bit.

Abstract: A method and apparatus for the drilling of the curved borehole portion of a horizontal or directional well. A tight radius of curvature is rotary drilled by use of flexible composite drilling pipe or other flexible pipe common to the industry which terminate within an eccentric collar on the final drill string section. The eccentric collar is equipped with a retractable and grooved compression pad which expands outwardly to hold the eccentric collar (which is also grooved on its opposite side) against the side of the well bore to prevent the eccentric collar from rotating during the rotary drilling process. The final drill string section connects to a lower drill bit collar and rotary drill bit through a driving ball and socket connection. The eccentric collar on the final drill string section that engages the well bore forces the deflection of the drill bit about the ball and socket connection and holds this orientation as the rotating drill proceeds forward.

Abstract: A rotary drill bit for drilling a curved subterranean borehole. In one embodiment, the drill bit comprises a side portion, a plurality of cutting elements that produce a lateral force on the drill bit in response to the rotation of the drill bit in the borehole, and bearing means. The bearing means is located on the side portion of the drill bit and contacts the borehole wall during drilling to receive a reactive force that is from the borehole, that is in response to the lateral force and that is directed to a location adjacent to the uphole end of the side portion of the drill bit. The reactive force and the lateral force form a downhole-moment that is about the drill bit and that is opposed by an uphole-moment having a force component that is directed at the flexible joint. The uphole end of the bearing means is located relatively close to the cutting elements such that the magnitude of the downhole-moment and the magnitude of the uphole-moment are minimized.

Abstract: A downhole steering tool comprises a hollow mandrel (11), an independently rotatable sleeve (12) extending over a portion of the mandrel (11), steering plungers (26) carried by the sleeve (12) and extendable and retractable laterally to and from pressure contact with the hole wall (28) for steering a drill below the tool when in use, releasable locking means (14) for locking the sleeve (12) to the mandrel (11) rotationally, and fluid control means (15) operable to direct to the locking means (14) and the steering plungers (26) a portion from fluid circulation through the mandrel (11) to release the locking means (14) and to extend the steering plungers (26) by means of pressure of the fluid.

Abstract: The adjusting device consists of at least one drill string element (40) integral in rotation with the drill string and fastened to the drill string in the vicinity of the drill bit. Element (40) comprises parts (41, 43, 46) whose outer bearing surfaces are arranged in a cylindric surface with substantially the axis (48) of the drill string as the axis and substantially the nominal diameter of hole (4) as the diameter, distributed around the axis so as to generate, during part of the rotation of the drill string, by reaction of the well of hole (4) on element (40) , forces tipping the drill bit out of the drilling plane. Bearing parts (45, 46) may consist partly of variable-diameter mobile blades.

Abstract: A device for selective straight or directional drilling in subterranean rock formations consists of a rotary drilling tool having a tool main axis and comprising a housing which comprises several sections and can be connected to a drill string, the housing having a down-hole motor for driving a drill bit through a driven shaft. For straight drilling, the housing can be set in independent, slow rotation about the tool main axis by being turned by the drill string, and for directional drilling can be aligned and fixed against turning. The lower section of the housing adjacent to the drill bit and mounting the driven shaft is deflected relative to the tool main axis, and this section is connected to an upper section by an intermediate section which has an axis which intersects the axes of the upper and lower section. The device may include a plurality of interchangeable intermediate sections.

Abstract: A flexible steering sub is disclosed for flexible drilling of horizontal wells, geothermal drilling for electric power generation; earth sciences study of and monitoring of earth movement with respect to fault movement; environmental science cleaning up of inaccessible polluted areas; coring to test rock strength prior to large scale constructions such as dams; introduction of chemicals for solution mining, and the like. The flexible sub comprises an elongated housing having a plurality of housing sections connectable at one end to an orientation sub for a PDM drill and connectable at the other end to a wire line connector. An electronics assembly including guidance directional sensors and probe is positioned in a plurality of the housing sections, interconnected electrically, and connected at one end to the wire line connector.

Abstract: A downhole adjustable blade stabilizer is disclosed for varying the position of stabilizer blades to provide an increased ability to control the direction of drilling. The adjustable blade stabilizer includes a plurality of blades mounted in an angled track to permit axial and radial movement of the blades. The blades are driven by a piston in response to a pressure differential created by a sufficient flow of drilling mud through the stabilizer. The stabilizer blades are retracted by a spring when the pressure differential is eliminated. A positioning piston limits blade extension to a desired position. The positioning piston moves in response to a command signal, and remains in place until a new command signal is received. By maintaining the positioning piston in a locked position, the position of the blades can be reset to the prior position after the loss of pressure differential. A measuring device is provided in association with the positioning piston to enable precise measurement of blade position.

Abstract: A telemetering system is disclosed for communicating command signals to a downhole adjustable blade stabilizer, and for transmitting encoded time/pressure signals back to the surface. The command signal provides information regarding a desired blade position for an adjustable blade stabilizer. The stabilizer sets a positioning piston in response to the command signal to limit the extent of blade expansion. A position sensor is provided in association with the positioning piston to measure precisely the position of the blades. An encoded signal is generated in response to the measurement and is transmitted to the surface in a combined time/pressure format to uniquely identify the position of the blades.

Abstract: A fitting for controlled trajectory drilling. This fitting comprises a downhole motor, a drilling tool, and a variable geometry stabilizer.

Abstract: Drilling fitting equipment is disclosed, comprising a drilling motor, a member to be actuated, an information detection unit and a power unit for controlling the member, the motor comprises an energy transformation zone for rotating a drilling tool, the zone having an upper end, the equipment comprising a flow of drilling fluid through the drilling fitting, wherein the member to be actuated and at least one of the elements of an assembly formed by the detection unit and the power unit are situated on opposite sides of the upper end.

Abstract: A curve drilling assembly operable with a rotary drill string is provided for drilling a curved subterranean borehole. The assembly includes a curve guide, a rotary drill bit, an imbalance force assembly, and a bearing assembly. The curve guide is connectable with the drill string for deflecting the drill string toward the outside radius of the curved borehole. The imbalance force assembly, which preferably is provided by selectably disposing cutting elements on the drill bit, is rotatable with the drill string for creating a net imbalance force along a net imbalance force vector substantially perpendicular to the longitudinal axis of the drill bit during drilling. The bearing assembly is rotatable with the drill string and is located in the curve drilling assembly near the cutting elements of the drill bit for intersecting a force plane formed by the longitudinal bit axis and the net imbalance force vector and for substantially continuously contacting the borehole wall during drilling.

Abstract: A device for guiding a drilling tool into a well and for exerting a hydraulic force on the drilling tool includes a tubular body and an outer sleeve rotating about the body and longitudinally displaceable with respect to the body. Also, the device includes radially displaceable pistons, in an extension position, that come into anchoring engagement with the wall of the well and immobilize the external sleeve, as well as a jack to displace the body and the drilling tool integral therewith with respect to the external sleeve and to exert a pushing force onto the tool. Hydraulic circuits and appropriate control assembly are also provided for controlling the execution of a series of successive cycles of anchoring of the external sleeve in the well and of displacement of the drilling tool with respect to the external sleeve.

Abstract: In accordance with illustrative embodiments of this invention, a downhole adjustable stabilizer includes a sleeve having outwardly extending blades and mounted for limited rotation on a mandrel, vertically aligned sets of radially movable buttons mounted in bores in the blades, and longitudinal flats on the outer periphery of the mandrel that when radially aligned with the respective sets of buttons allows them to shift inward to positions where the stabilizer becomes undergage and can be tilted in the borehole. Some spring loaded buttons drag against the borehole wall to provide frictional restraint against rotation of the housing. The blades can each have an inclined side surface that causes the sleeve to be rotated to its position relative to the mandrel where the sets of buttons are retracted as the stabilizer slides downward in the borehole.

Abstract: The invention relates generally to rotary drilling equipment, and more particularly to stabilizers which are specifically adapted for use during directional drilling when only the drill bit is rotated using a down-hole motor, but which are also well suited for use during conventional drilling when the entire drill string is rotated. In a preferred embodiment, this is achieved by using three longitudinal ribs on the stabilizer body, one of which is displaced laterally in a down-hole direction and is radially oriented such that it contacts the low side of the borehole during directional drilling.

Abstract: The present invention provides an apparatus for orienting a drilling tool in a borehole, and which employs drilling mud pressure to selectively hydraulically move force-transmitting elements associated with pressure members on the exterior of the tool against the wall of the borehole, or to radially shift the drive shaft of the drilling tool in the tool casing. The tool may also include a drilling mud powered centering mechanism for maintaining the tool or the drive shaft within the tool in a centered basic position. A tool may include both pressure members and a shiftable drive shaft, as well as centering mechanisms to act on both the pressure members and the drive shaft.

Abstract: An aluminum pipe joint is disclosed for use in a drill string for drilling wells having a well bore with a substantially non-vertical section where the portion of the drill string located in the non-vertical section is in compression and is urged into engagement with the low side of the hole by gravity. The pipe joint includes an elongated tubular member of aluminum the outer surface of which is a machined surface. The tubular member has an outside diameter equal to the outside diameter of a standard joint of drill pipe over a substantial portion of its length. A section of increased diameter is located about midway between the ends of the joint and portions of enlarged diameter are located adjacent each end of the pipe joint. The latter portions have a diameter equal to the diameter of the external upset required for tool joints. They also increase the buckling strength of the joint. Steel tool joints are attached to each end of the tube.

Abstract: An apparatus for pushing a hose along a conduit includes a rotatable reel, a hose wound on the reel, and a driving arrangement for drawing the hose off the reel and for pushing the hose into and along a conduit. The apparatus can also include an arrangement attached to a leading end of the hose for permitting the leading end of the hose to roll along the interior surface of the conduit. Also, a guide can be positioned in the access opening to the conduit in order to permit the hose to move more easily through sharp turns.

Abstract: The device comprises a set of rods having a first end, by means of which the rotation is transmitted to the set of rods and the axial force to the tool (3) during drilling, and a second end to which the tool (3) is fastened. The device comprises means for adjusting the azimuth angle of the path of the drilling tool which consists of a tubular body (10) comprising a radially projecting bearing blade (11) and mounted rotatably on the set of rods (2), and a remotely actuable junction means making it possible to fix the set of rods (2) and the tubular body (10) relative to one another in terms of rotation in its active position. In the inactive position of the junction means, the set of rods (2) is freely rotatable within the tubular body which is held immobile in terms of rotation in the drill hole by means of the bearing blade (11). The bearing blade (11) is placed in the drill hole in an angular orientation making it possible to adjust the azimuth angle in the desired direction.

Abstract: A directional drilling apparatus and method in which the drill bit is coupled to the lower end of a drill string through a universsal joint which allows the bit to pivot relative to the string axis. The bit is contra-nutated in an orbit of fixed radius and at a rate equal to string rotation but in the opposite direction. This speed-controlled and phase-controlled bit nutation keeps the bit heading off-axis in a fixed direction. The invention enables directional drilling while the drill string rotates normally.

Abstract: The present invention relates to a method and apparatus for navigational driling in earth formations, the apparatus including a downhole drilling assembly having a drill bit driven by a downhole motor and a deflection element or elements in the assembly for imparting an angle of deflection to the drill bit relative to the drill string above the drilling assembly. At least two stabilization points for the drilling assembly in the borehole are used, with the drill bit, to define an arcuate path for the drilling assembly when the downhole motor is operating but the drill string is not rotating. When the drill string is rotated, the drilling assembly drills a substantially straight or linear borehole.

Abstract: A selectively adjustable double bend positive positioning directional drilling system for kickoff from a main well bore to change the directiion of drilling. The tool is selectively adjustable to facilitate running into the vertical well bore and subsequently to provide an aggressive build rate upon kickoff. The tool string incorporates a pair of kickoff pads--a lower fixed pad and an upper rotatively adjustable pad. As the tool is run into the well bore the adjustable pad is oriented away from the bend in the motor housing. Once in the hole, the string would be rotated relative to the adjustable pad by the reactive torque of the downhole motor and locked in the desired orientation. The adjustable pad incorporates an internal slot system to guide rotation and lock the pad in position. Alternatively, a single arm underreamer-type assembly could be used as the upper kickoff pad.

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

Abstract: A system and method for controlled directional drilling utilizes a system approach to design the hardware for drilling according to the well plan. The bend angle of a bent housing, connected between the bit and downhole motor, the diameter of a plurality of stabilizers and placement of the stabilizers with respect to the drill bit are selected and predetermined on the basis of the desired well plan. With the use of an MWD, the direction of the progressing borehole is tracked from the surface. Direction changes as required are controlled from the surface simply by controlling rotation of the drillstring. For curved path drilling, only the downhole motor is rotated, causing the borehole to travel along the curve determined by the bend angle in the bent housing and the diameter and location of the concentric stabilizers. When straight hole drilling is required, both the downhole motor and the entire drill string are rotated, effectively nullifying the effect of the bend angle in the bent housing.