Abstract: System and method of controlling a trajectory of a wellbore comprises conveying a drilling assembly in the wellbore by a rotatable tubular member. The drilling assembly includes a drill bit at an end thereof that is rotatable by a drilling motor carried by the drilling assembly. The drilling assembly has a first adjustable stabilizer and an second stabilizer spaced apart from the first adjustable stabilizer. The first adjustable stabilizer having set of ribs spaced around the stabilizer, with each rib being independently radially extendable. The position of a first center of the first adjustable stabilizer is adjusted in the wellbore relative to a second center of the second stabilizer in the wellbore for controlling the trajectory of the wellbore.

Abstract: A steering tool for use in drilling a borehole, including a tubular housing, a tool actuating device movably supported within the housing, a plurality of hydraulically actuated steering devices circumferentially spaced about the housing, and a hydraulic control system interposed between the tool actuating device and the steering devices for converting an actuating movement of the tool actuating device to independent actuation of the steering devices.

Abstract: A preferred embodiment of a system for rotating and guiding a drill bit in an underground bore includes a drilling motor and a drive shaft coupled to drilling motor so that drill bit can be rotated by the drilling motor. The system further includes a guidance module having an actuating arm movable between an extended position wherein the actuating arm can contact a surface of the bore and thereby exert a force on the housing of the guidance module, and a retracted position.

Abstract: A bi-stable actuator comprises a chamber 40 having a fluid inlet 34 and first and second fluid outlets 36, 38, a valve member 42 movable between a first position in which it co-operates with a first seat to close the first outlet 36 and a second position in which it co-operates with a second seat to close the second outlet 38, and an electromagnetic actuator 48 operable to drive the valve member 42 between its first and second positions, wherein the valve member 42 has a first surface 44 against which the fluid pressure within the chamber 40 acts when the valve member 42 is in its first position to resist movement of the valve member 42, and a second surface 46 against which the fluid pressure within the chamber 40 acts when the valve member 42 is in its second position to resist movement of the valve member 42.

Abstract: A downhole steering tool is disclosed. The steering tool includes a rotatable shaft, a substantially non-rotating tool body deployed about the shaft, and a plurality of force application members deployed on the steering tool body. The steering tool further includes a bendable section deployed in the steering tool body. The bendable section is disposed to bend preferentially relative to the steering tool body under an applied bending load. The use of a steering tool body having a bendable section tends to advantageously reduce bending stresses in the steering tool body during use. Moreover, tools embodying this invention may be suitable for higher dogleg severity applications.

Abstract: Aspects of this invention include a steering tool having a controller configured to provide closed-loop control of hydraulic fluid pressure. In one exemplary embodiment, closed-loop control of a system (reservoir) pressure may be provided. In another embodiment, closed-loop control of a blade pressure may be provided while the blade remains substantially locked at a predetermined position. Other exemplary embodiments may incorporate rule-based-intelligence such that pressure control thresholds may be determined based on various measured and/or predetermined downhole parameters. The invention tends to reduce the friction (drag) between the blades and the borehole wall and thereby also tends to improve drilling rates. Moreover, the invention also tends to improve the service life and reliability of downhole steering tools.

Abstract: A drilling stabilization system includes a power section coupled to an upper end of a transmission housing, a bearing housing coupled to a lower end of the transmission housing, and a drill bit coupled to the bearing housing, wherein the transmission housing includes at least two radially outwardly extending blades disposed on the transmission housing. A method of drilling a substantially concentric wellbore includes drilling a formation with a directional drilling bottomhole assembly coupled to a drill string, changing a direction of the drilling of the formation being drilled, removing the directional drilling bottomhole assembly from the drill string, coupling a drilling stabilization system to the drill string, and drilling the formation with the drilling stabilization system.

Abstract: In a drilling apparatus of the type comprising a rotatable drilling shaft and a housing for rotatably supporting a length of the drilling shaft for rotation therein, a rotation restraining device associated with the housing for restraining rotation of the housing. In one embodiment, the rotation restraining device is comprised of at least one roller on the housing, the roller having an axis of rotation substantially perpendicular to a longitudinal axis of the housing and being oriented such that it is capable of rolling about its axis of rotation in response to a force exerted on the roller substantially in the direction of the longitudinal axis of the housing. In a further embodiment, the rotation restraining device is comprised of at least one piston on the housing.

Abstract: The present invention provides a drilling assembly for drilling deviated wellbores. The drilling assembly includes a drill bit at the lower end of the drilling assembly. A drilling motor provides the rotary power to the drill bit. A bearing assembly of the drilling motor provides lateral and axial support to the drill shaft connected to the drill bit. A steering device is integrated into drilling motor assembly. The steering device contains a plurality of force application members disposed at an outer surface of the drilling motor assembly. Each force application member is adapted to move between a normal position and a radially extended position to exert force on the wellbore interior when in extended position. A power unit in the housing provides pressurized fluid to the force application members. A control device for independently operating each of the force application members is disposed in the drilling motor assembly.

Abstract: A bottomhole assembly (BHA) for single trip sidetracking operations has a mill for forming an open hole section in a cased wellbore and a steering unit for controlling drill bit orientation. During use, the drilling system is assembled at the surface and tripped into the wellbore. The mill is positioned adjacent a kick-off point and operated to form an open hole section. Thereafter, the drill bit is positioned adjacent the open hole section. An exemplary steering unit includes one or more force application members that, when energized, displace the drill bit such that the bit is pointed in a specified direction into the open hole section. The steering unit also includes one or more force application members that facilitate directional drilling through the open hole section. Other suitable steering units can employ devices that alter the BHA centerline geometry.

Abstract: An apparatus for steerable rotary drilling of a borehole having a wall in the earth comprising a mandrel having a central opening there through for the passage of drilling fluids. The mandrel having a lower connection for operatively connecting to a drill bit structure and an upper connection for operatively connecting to a drill string above said apparatus. The mandrel further having an intermediate portion, an outer housing surrounding longitudinal extent of the mandrel intermediate portion, a differential displacement drive within the outer housing, one or more pairs of radially-extensible, opposed side-force exerting elements controlled by the differential displacement drive to provide for side force exertion against the borehole wall.

Abstract: According to one embodiment of the invention, a rotary steerable tool includes a drive shaft configured to be coupled to a drill string at an upper end thereof and configured to be coupled to a drilling tool at a lower end thereof. A middle portion of the drive shaft is disposed axially between the upper and lower ends and has a smaller diameter than each of the upper and lower ends. The drive shaft further includes a housing rotatably coupled externally to the drive shaft and at least one housing module coupled to a respective opening in the housing at an axial location corresponding to the middle portion of the drive shaft.

Abstract: A borehole may be drilled utilizing the bottom hole assembly 10, 50 with a downhole motor 14, which may offset at a selected bend angle. A gauge section 34 is secured to the bit 16 has a uniform diameter bearing surface along an axial length of at least 60% of the bit diameter. The axial spacing between the bend and the bit face is controlled to less than fifteen times the bit diameter. After drilling a section of the well with the BHA according to the present invention, a tubular may be inserted in the well by passing the tubular through an upper tubular, then the inserted tubular expanded while downhole to a diameter substantially equal to the expanded tubular.

Abstract: A bottom hole assembly is rotatably adapted for drilling directional boreholes into an earthen formation. It has an upper stabilizer mounted to a collar, and a rotary steerable system. The rotary steerable system has an upper section connected to the collar, a steering section, and a drill bit arranged for drilling the borehole attached to the steering section. The steering section is joined at a swivel with the upper section. The steering section is actively tilted about the swivel. A lower stabilizer is mounted upon the steering section such that the swivel is intermediate the drill bit and the lower stabilizer.

Abstract: A variable gauge drilling apparatus and a method for assembling a variable gauge drilling apparatus for insertion in a subject borehole. The variable gauge drilling apparatus includes: an apparatus housing having a housing size which is suitable for insertion in a subject borehole which has a subject borehole size within a design range of borehole sizes; a plurality of interchangeable borehole engaging devices having different device sizes for mounting on the apparatus housing to provide the drilling apparatus with a drilling apparatus size within a range of drilling apparatus sizes, wherein the range of drilling apparatus sizes is compatible for use of the drilling apparatus within the design range of borehole sizes; and a universal borehole engaging device mount located on the apparatus housing, wherein the mount is configured to accept for mounting any one of the plurality of interchangeable borehole engaging devices.

Abstract: An expandable centralizer is disclosed having a body having a first portion of circular cross-section and a second portion of polyhedral cross-section. Centralizing members are arranged on the faces of the second portion which, in a first position, limit the diameter of the tool so that it can pass through small openings in a wellbore. The centralizing members can then be moved hydraulically across the faces to extend and provide support for the expandable downhole tool in larger openings within the wellbore.

Abstract: A stabiliser (10) has a body (12) having a through-bore (16). A mandrel (14), also having a through-bore (20), is axially slidable in the body bore to actuate and de-actuate the tool. A step (64) in the body defines annular chambers (102, 104) between the mandrel and body on either side of the step. A control piston (18) in the mandrel alternately directs drilling mud pumped under pressure along said body bore and mandrel bore to the chambers to drive the mandrel hydraulically to actuate and de-actuate the tool. The control piston has a through-bore (46) and is slidable in the mandrel bore against the force of a return spring (40) by drilling mud pressure from a low-pressure position to a pressure position. The pressure position is alternately one of an actuate position (a) and a de-actuate position (b), axially spaced along the mandrel bore from said actuate position.

Abstract: An autonomous subsurface drilling device has spaced-apart forward and rearward “feet” sections coupled to an axial thruster mechanism between them to operate using an inchworm method of mobility. In one embodiment, forward and rearward drill sections are carried on forward and rearward “feet” sections for drilling into material in the borehole in both forward and rearward directions, to allow the device to maneuver in any direction underground. In another embodiment, a front drill section has a drill head for cutting into the borehole and conveying cuttings through a center spine tube to an on-board depository for the cuttings. The feet sections of the device employ a foot scroll drive unit to provide radial thrust and synchronous motion to the feet for gripping the borehole wall. The axial thrust mechanism has a tandem set of thrusters in which the second thruster is used to provide the thrust needed for drilling, but not walking.

Abstract: The present invention provides a drilling assembly for drilling deviated wellbores. The drilling assembly includes a drill bit at the lower end of the drilling assembly. A drilling motor provides the rotary power to the drill bit. A bearing assembly of the drilling motor provides lateral and axial support to the drill shaft connected to the drill bit. A steering device is integrated into drilling motor assembly. The steering device contains a plurality of force application members disposed at an outer surface of the drilling motor assembly Each force application member is adapted to move between a normal position and a radially extended position to exert force on the wellbore interior when in extended position. A power unit in the housing provides pressurized fluid to the force application members. A control device for independently operating each of the force application members is disposed in the drilling motor assembly.

Abstract: Directional drilling apparatus for use in drilling a deviated bore comprises a mandrel for mounting to a drill string and having a main axis. A non-rotating mass is rotatably mounted on the mandrel and has a center-of-gravity spaced from the mandrel axis. The apparatus further comprises an offsetting arrangement including a non-rotating offsetting portion rotatably mounted on the mandrel, coupled to the mass, and having an outer profile defining an offset relative to the mandrel axis, and a bearing portion rotatably mounted on the offsetting portion. In use, the apparatus is run into an inclined bore on a string, and the offsetting portion is oriented relative to the mass. When the string is rotated the mass tends towards an orientation with its center-of-gravity positioned towards the low side of the bore and thus tends to maintain the offsetting portion in a desired relative orientation in the bore, the bearing portion rotationally isolating the offsetting portion from the bore wall.

Abstract: A directional casing drilling system including a casing string for rotation of a drill bit, a shaft coupled to the casing string, and a sleeve having pads that are hydraulically extensible. The sleeve may be positioned about a portion of the shaft. The invention may also include a tube connecting the sleeve to the drill collar, the tube adapted to conduct drilling fluid, and a valve system adapted to operatively conduct at least a portion of the drilling fluid to the pads whereby the pads move between an extended position and a retracted position.

Abstract: A closed-loop drilling system utilizes a bottom hole assembly (“BHA”) having a steering assembly having a rotating member and a non-rotating sleeve disposed thereon. The sleeve has a plurality of expandable force application members that engage a borehole wall. A power source and associated electronics for energizing the force application members are located outside of the non-rotating sleeve. A preferred drilling system includes a surface control unit and a BHA processor cooperate to guide the drill bit along a selected well trajectory in response to parameters detected by one or more sensors. In a preferred closed-loop mode of operation, the BHA processor automatically adjusts the force application members in response to data provided by one or more sensors. In a preferred embodiment, the non-rotating sleeve and rotating member include a sensor that determines the orientation of the sleeve relative to the rotating member.

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: An apparatus and method for removing cuttings in a deviated borehole using drilling fluids. The apparatus includes a pipe string and a bottom hole assembly having a down hole motor and bit for drilling the borehole. The pipe string has one end attached to the bottom hole assembly and does not rotate during drilling. The apparatus and methods raise at least a portion of the pipe string in the deviated borehole to remove cuttings from underneath the pipe string portion.

Abstract: The invention refers to a drilling tool and method that, among other aspects, provides for a sleeve with expansible pads for positioning the drilling tool in the desired direction during drilling. The pads are hydraulically expanded and retracted by a valve system which selectively diverts mud flowing through the tool to the desired pads. The tool may also be provided with a flexible tube connecting the sleeve to drilling tool for maneuvering along deviations or curves in the wellbore.

Abstract: A steering tool for extended-reach directional drilling in three dimensions comprises a mud pulse telemetry section, a rotary section, and a flex section assembled as an integrated system in series along the length of the tool. The flex section comprises a flexible drive shaft and a deflection actuator for applying hydraulic pressure along the length of the shaft for bending the shaft when making inclination angle adjustments during steering. The rotary section comprises a rotator housing coupled to the deflection housing for rotating the deflection housing for making azimuth angle adjustments during steering. The onboard mud pulse telemetry section receives inclination and azimuth angle steering commands together with actual inclination and azimuth angle feedback signals during steering for use in controlling operation of the flex section and rotary section for steering the tool along a desired course.

Abstract: A downhole tool for use in a well bore is provided. The tool includes a tool body and at least one elongated sprung member deployed on an outer surface thereof. The sprung member is configured to lie in a rest position substantially parallel to the outer surface and further includes at least one movable end that is movable with respect to the tool body. The tool further includes an actuation module deployed on the tool body. The actuation module is operably engaged with the sprung member, and disposed, upon actuation, to deflect said movable end thereof away from the rest position. Displacement of the movable end of the sprung member causes elastic spring biasing of the sprung member via bending thereof. The biasing urges the sprung member to return to the rest position upon de-actuation of the actuation module.

Abstract: A steering tool for extended-reach directional drilling in three dimensions comprises a mud pulse telemetry section, a rotary section, and a flex section assembled as an integrated system in series along the length of the tool. The flex section comprises a flexible drive shaft and a deflection actuator for applying hydraulic pressure along the length of the shaft for bending the shaft when making inclination angle adjustments during steering. The rotary section comprises a rotator housing coupled to the deflection housing for rotating the deflection housing for making azimuth angle adjustments during steering. The onboard mud pulse telemetry section receives inclination and azimuth angle steering commands together with actual inclination and azimuth angle feedback signals during steering for use in controlling operation of the flex section and rotary section for steering the tool along a desired course.

Abstract: Directional drilling apparatus having a non-rotating mass rotatably a centre-of-gravity spaced form the mandrel axis. An offsetting arrangement is coupled to the mass, and has an outer profile defining an offset relative to the mandrel axis, and a bearing portion rotatably mounted on the offsetting portion. The apparatus is run on a string, and the offsetting portion is oriented relative to the mass. When the towards an orientation with its centre-of-gravity positioned towards the low side of the bore and tends to maintain the relative orientation.

Abstract: The invention concerns a method which includes the steps of: introducing into a pre-drilled portion of a well (16) a drilling system containing a drilling bit (11) assembled with tubular lining elements (15), an element for measuring the inclination and azimuth direction of the pre-drilled part of the well, an element for rotary friction (26, 27) against the wall of the pre-drilled part and an element capable of modifying the friction coefficient of the friction element against the wall; measuring the azimuth direction of the pre-drilled part of the well (16); and varying the friction coefficient of the friction element (26, 27) sufficiently to influence the azimuth direction of the next well portion to be drilled.

Abstract: The present invention provides a drilling assembly for drilling deviated wellbores. The drilling assembly includes a drill bit at the lower end of the drilling assembly. A drilling motor provides the rotary power to the drill bit. A bearing assembly of the drilling motor provides lateral and axial support to the drill shaft connected to the drill bit. A steering device is integrated into drilling motor assembly. The steering device contains a plurality of force application members disposed at an outer surface of the drilling motor assembly Each force application member is adapted to move between a normal position and a radially extended position to exert force on the wellbore interior wherein in extended position. A power unit in the housing provides pressurized fluid to the force application members. A control device for independently operating each of the force application members is disposed in the drilling motor assembly.

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: The present invention provides a drilling assembly for drilling deviated wellbores. The drilling assembly includes a drill bit at the lower end of the drilling assembly. A drilling motor provides the rotary power to the drill bit. A bearing assembly of the drilling motor provides lateral and axial support to the drill shaft connected to the drill bit. A steering device is integrated into drilling motor assembly. The steering device contains a plurality of force application members disposed at an outer surface of the drilling motor assembly. Each force application member is adapted to move between a normal position and a radially extended position to exert force on the wellbore interior when in extended position. A power unit in the housing provides pressurized fluid to the force application members. A control device for independently operating each of the force application members is disposed in the drilling motor assembly.

Abstract: A drilling assembly for drilling deviated wellbores includes a drill bit and a drilling motor that provides rotary power to the drill bit. A steering device integrated into drilling motor assembly contains a plurality of force application members. In one embodiment, each force application member is adapted to exert an adjustable amount of force on the wellbore interior. A separate or common power unit at or uphole of the drilling motor provides power to the force application members. A control device and control circuit can cooperate to independently operate each of the force application members. An inductive transmission device can be used to transmit electrical signals and/or power between rotating and non-rotating section of the drilling motor. During drilling of a wellbore, the force application members are operated to adjust the force on the wellbore to drill the wellbore in the desired direction.

Abstract: A steering apparatus for an auger in its casing to bore a horizontal hole in earth by utilizing four expandable and retractable wings equally spaced at the head of the casing. The wings are actuated by integrated single action low profile hydraulic cylinders energized by external single action hydraulic cylinders to minimize the diameter of the hole bored due to State building codes. Two embodiments of the wings are shown.

Abstract: The present invention provides a drilling assembly that includes a mud motor that rotates a drill bit and a set of independently expandable ribs. A stabilizer uphole of the ribs provides stability. A second set of ribs may be disposed on the drilling assembly. Vertical and curved holes are drilled by rotating the drill bit by the mud motor and by independently adjusting the rib forces. The drill string is not rotated. Inclined straight sections and curved sections may be drilled by independent adjustment of the rib forces and by rotating the drill bit with the motor, without rotating the drill string. Inclined sections or curved sections in the vertical plane are drilled by superimposing the drillstring rotation on the mud motor rotation and by setting the rib forces to the same predetermined values. Rib forces are adjusted if the drilling direction differs from the defined inclination. The system is self-adjusting and operates in a closed loop manner.

Abstract: The device 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: A bottom hole assembly is rotatably adapted for drilling directional boreholes into an earthen formation. It has an upper stabilizer mounted to a collar, and a rotary steerable system. The rotary steerable system has integral drilling motor, an upper section connected to the collar, a steering section, and a drill bit arranged for drilling the borehole attached to the steering section. The steering section is joined at a swivel with the upper section. The steering section is actively tilted about the swivel. A lower stabilizer is mounted upon one of the upper section or the steering section such that the swivel is intermediate the drill bit and the lower stabilizer.

Abstract: A bottom hole assembly is rotatably adapted for drilling directional boreholes into an earthen formation. It has an upper stabilizer mounted to a collar, and a rotary steerable system. The rotary steerable system has an upper section connected to the collar, a steering section, and a drill bit arranged for drilling the borehole attached to the steering section. The steering section is joined at a swivel with the upper section. The steering section is actively tilted about the swivel. A lower stabilizer is mounted upon the steering section such that the swivel is intermediate the drill bit and the lower stabilizer.

Abstract: A gripper assembly for anchoring a tractor within a downhole passage and for assisting movement of the tractor within the passage. The gripper assembly includes an elongated mandrel and flexible toes that can be radially displaced to grip onto the surface of the passage. The toes are displaced by the interaction of a driver slidable on the mandrel and a driver interaction element on the toes. In one embodiment, the toes are displaced by the interaction of rollers and ramps that are longitudinally movable with respect to one another. In another embodiment, the toes are displaced by the interaction of toggles that rotate with respect to the toes.

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 drilling shaft deflection assembly for a drilling direction control device of the type comprising a rotatable drilling shaft and a housing for supporting a length of the drilling shaft for rotation therein. The deflection assembly is contained within the housing and is axially located between a first support location and a second support location for bending the drilling shaft between the first support location and the second support location. The deflection assembly includes a deflection mechanism for imparting lateral movement to the drilling shaft to bend the drilling shaft, a deflection actuator for actuating the deflection mechanism in response to longitudinal movement of the deflection actuator, and a deflection linkage mechanism between the deflection mechanism and the deflection actuator for converting longitudinal movement of the deflection actuator to lateral movement of the drilling shaft.

Abstract: Grip and guiding device for directional drilling, in order to drill straight or curved holes with a predetermined path. The device includes a drill string (11-21) comprising parts which rotate during drilling, including a drill bit (11) or a water hammer on its front end and a non-rotating packer unit (14) with a packer tubing (28) comprising one or several projecting pressure pads (25,31-32) arranged behind the drill bit (11) or the water hammer. The pressure pad or pads are arranged to be pressed out towards the drill hole wall by means of the pressure from a drill fluid when this exceeds a certain level. The pressure pad (25) or the pressure pads (25A-25C) may be arranged asymmetrically and/or affects the packer tubing (28) asymmetrically, e.g. by having different heights. The pressure pad(s) force guiding ribs on the opposite side into the hole wall in order to prevent rotation of the packer unit (14). The pressure pad or pressure pads can on deactivation be withdrawn for performing linear drilling.

Abstract: The present invention provides a drilling assembly that includes a mud motor that rotates a drill bit and a set of independently expandable ribs. A stabilizer uphole of the ribs provides stability. A second set of ribs may be disposed on the drilling assembly. Vertical and curved holes are drilled by rotating the drill bit by the mud motor and by independently adjusting the rib forces. The drill string is not rotated. Inclined straight sections and curved sections may be drilled by independent adjustment of the rib forces and by rotating the drill bit with the motor, without rotating the drill string. Inclined sections or curved sections in the vertical plane are drilled by superimposing the drillstring rotation on the mud motor rotation and by setting the rib forces to the same predetermined values. Rib forces are adjusted if the drilling direction differs from the defined inclination. The system is self-adjusting and operates in a closed loop manner.

Abstract: An apparatus for selectively controlling the direction of a well bore comprising a mandrel rotatable about a rotation axis; a direction controller means comprising at least two parts configured to apply a force to said mandrel with a component perpendicular to the said rotation axis; a housing having an eccentric longitudinal bore forming a weighted side and being configured to freely rotate under gravity; and a driver for selectively varying the angle of the force relative to the weighted side of the housing about said rotation axis, the driver being configured to move the two parts independently of one another.

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: There is provided an adjustable housing for use with a drill string for controlled directional drilling of a well hole. The housing includes an upper sub and a lower sub each having a first portion extending along a primary axis and a second portion extending along a secondary axis offset from the primary axis by a predetermined angle. The second portions are rotatably mounted together such that the secondary axes of the respective upper and lower subs are coincident. The upper sub is thus rotatable in relation to the lower sub between a bent position wherein the primary axes of the upper and lower subs are misaligned and a parallel position wherein the primary axes of the upper and lower subs are parallel to each other. A locking member is slidably mounted on splines extending radially from the second portion of the upper sub such that the locking member is slidable between an engaged position and disengaged position.

Abstract: A rotary steering apparatus including a drill string, a drill bit, a main body connected at one end to the drill string and at another end to the drill bit, a sleeve extending around the main body such that the main body is freely rotatable within the sleeve, and a locking member affixed to the main body and interactive with the sleeve. The sleeve has at least one protruding pad extending outwardly therefrom so as to bear against a well bore. The locking member serves to lock the sleeve relative to the main body such that the sleeve rotates correspondingly with a rotation of the main body. The locking member locks the sleeve onto the main body relative to an increased flow rate of fluid through the interior passageway of the main body. The locking member includes a flipper pivotally connected to the main body so as to extend into the longitudinal passageway and a spring resiliently connected to the flipper so as to urge the flipper into the interior passageway with a desired spring rate.

Abstract: The present invention provides a drilling assembly for drilling deviated wellbores. The drilling assembly includes a drill bit at the lower end of the drilling assembly. A drilling motor provides the rotary power to the drill bit. A bearing assembly of the drilling motor provides lateral and axial support to the drill shaft connected to the drill bit. A steering device is integrated into drilling motor assembly. The steering device contains a plurality of force application members disposed at an outer surface of the drilling motor assembly Each force application member is adapted to move between a normal position and a radially extended position to exert force on the wellbore interior when in extended position. A power unit in the housing provides pressurized fluid to the force application members. A control device for independently operating each of the force application members is disposed in the drilling motor assembly.

Abstract: A stabilizer especially adapted for use with an drill string having an eccentric drilling element, such as a bi-center bit. The stabilizer has a pair of circumferentially displaced blades that lie in a common circumferential plane and extend from a rotatable sleeve supported on the stabilizer body, as well as a stationary blade. The rotating blades are aligned with the stationary blade when in a first circumferential orientation and are disposed so that the mid-point between the rotating blades is located opposite the stationary blade, thereby providing full-gauge stabilization, when the rotating blades are in a second circumferential orientation. A magnetic systems senses the circumferential orientation of the rotating blades and transmits the information to the surface via mud pulse telemetry. A piston actuated by the drilling mud locks the rotating blades into the active and inactive positions.