Abstract: A technique facilitates control over the orientation of a bottom hole assembly. A planetary gearbox assembly incorporates a sun wheel which cooperates with planet wheels at a plurality of levels along the planetary gear box assembly. The sun wheel and the planet wheels cooperate to convert rotational input to rotational output through an output carrier. Torsional rigidity characteristics of the sun wheel and the output carrier are selected to distribute torque loading across the plurality of levels of the planetary gear box assembly. The distributed forces reduce the potential for component failure.

Abstract: A well system may be provided comprising a first primary inductive coupler configured to be communicably coupled to a surface device and a first secondary inductive coupler. The first secondary inductive coupler may be further configured to be communicably coupled to one or more completion components provided in a first portion of the well. In addition, the well system may comprise a second primary inductive coupler configured to be communicably coupled to the surface device and a second secondary induction coupler. The second secondary inductive coupler may be further configured to be communicably coupled to one or more completion components provided in a second portion of the well. The flow through at least one of the first and second portions of the well may be adjusted via at least one of the one or more completion components. A method for completing a well comprising inductive couplers may also be provided.

Abstract: A method for forming lateral boreholes from an existing parent wellbore is provided. The wellbore has been completed with a string of production casing. The method generally comprises providing a downhole tool assembly having a whipstock. The method also includes running the assembly down into the parent wellbore. A force is applied to the assembly to cause the whipstock to rotate within the wellbore into an operating position. In this position, a curved face of the whipstock forms a bend-radius substantially across the inner diameter of the casing. A jetting hose is run into the wellbore. Upon contact with the curved face of the whipstock, the jetting hose is re-directed through a window in the production casing. Hydraulic fluid is injected under pressure through the hose to provide hydraulic jetting. The hose is directed through the window and into the formation to create a lateral borehole extending many feet outwardly into a subsurface formation.

Abstract: A drill bit direction system and method is disclosed that modifies or biases the stochastic movement of the drill bit and/or stochastic interactions between the drill bit and an inner-wall of a borehole being drilled by a drilling system to change the direction of drilling of the drilling system. The direction of the drill bit is monitored to determine if the direction happens to align in some way with a preferred direction. If the direction isn't close enough to a preferred direction, a biasing mechanism modifies the stochastic movement in an attempt to modify the direction closer to the preferred direction. Any of a number of biasing mechanisms can be used. Some embodiments can resort to conventional steering mechanisms to supplement the biasing mechanism.

Abstract: A method for drilling a wellbore comprises extending a rotatable drill string in the wellbore, where the drill string has a bottom hole assembly coupled to a bottom end thereof. A lower section of the bottom hole assembly comprising a steering apparatus is coupled to an upper section of the bottom hole assembly with a controllably adjustable clutch. A steering apparatus toolface angle is detected. The clutch is controllably adjusted to maintain the steering apparatus toolface angle within a predetermined range about a target steering apparatus toolface angle while rotating the upper section with the drill string.

Abstract: A method of servicing a wellbore comprises running a toolstring into a wellbore to a first depth, actuating a controllably rotating sub-assembly of the toolstring to rotate, and activating a pressure activated bendable sub-assembly of the toolstring to bend, wherein actuating the controllably rotating sub-assembly to rotate and activating the pressure activate bendable sub-assembly are performed in any sequence or concurrently. The method also comprises running the toolstring into the wellbore beyond the first depth and stabbing the toolstring into a window in a wall of the wellbore to enter a lateral wellbore, wherein no whipstock is used to facilitate stabbing into the window. The method further includes running the toolstring into the lateral wellbore and performing a wellbore servicing operation in the lateral wellbore.

Abstract: Methods and apparatus to form a well are disclosed. An example method involves determining a reservoir fluid map associated with at least a portion of a reservoir. The first fluid map has first fluid composition data associated therewith. The example method also involves measuring a formation fluid and determining a second fluid composition data based on the measurement. The second fluid composition data is compared with the first fluid composition data associated with the reservoir fluid map, and a well trajectory is adjusted based on the comparison.

Abstract: A drilling system for drilling a lateral borehole from a main borehole comprises a tubular conduit through which a fluid can be pumped, and a drilling assembly connected to the tubular conduit so as to receive fluid pumped therethrough. The drilling assembly comprises a power conversion unit, through which the fluid flows and which operates to provide a downhole power output; a drilling unit including a drilling apparatus powered by the output of the power conversion unit and operable to drill a lateral borehole into the formation surrounding the main borehole, and a liner unit for storing one or more liners for installation into the lateral borehole; and an anchor unit operable to anchor the drilling assembly in the main borehole when the drilling unit operates to drill the lateral borehole.

Abstract: An apparatus for use in a wellbore is provided that in one aspect includes: a drilling assembly configured to carry a first drill bit at an end thereof, a second drill bit disposed uphole of the first drill bit, and a connection device that is configured to selectively connect the second drill bit to the drilling assembly and disconnect the second drill bit from the drilling assembly.

Abstract: A system for orienting a drill bit prior to drilling into a formation, comprising a first pipe having an inside pipe diameter, the first pipe being positioned in a hole in the formation, and a curved shoe positioned in said first pipe at a desired orientation, said curved shoe including a funnel portion having an outlet that is off-center within the first pipe and a guide portion having a guide inlet in communication with the funnel outlet and an guide outlet that is off-center within the first pipe, the guide outlet occupying a different azimuthal position within the first pipe than is occupied by the guide inlet.

Abstract: A technique facilitates control over the orientation of a bottom hole assembly. The bottom hole assembly comprises an orienting tool having a dual-spline drive which, in turn, comprises a first lead screw portion and a second lead screw portion having threads of a first pitch and a second pitch, respectively. A motor is connected to the dual-spline drive to impart rotational motion with respect to the first threads having the first pitch. A difference in pitch between the first pitch and the second pitch enables the rotational motion imparted by the motor to be converted to a slower, higher torque, output via the second lead screw portion. As a result, the orienting tool is able to provide a selective, high torque, low-speed adjustment to the drilling orientation of the bottom hole assembly.

Abstract: In certain embodiments, a steerable drilling tool is provided including a rotatable shaft extending through a housing where the shaft and the housing are separated by at least one bearing or two sets of bearings, the shaft having a first portion terminating at a first end of the shaft and a second portion terminating at a second end of the shaft. The steerable drilling tool may further include a drill bit structure operatively coupled to the first portion and a steering subsystem comprising a pair of bearings operatively coupled to the first portion. The steering subsystem may be configured to angulate the shaft by exerting force substantially through the pair of bearings. In certain embodiments, the first portion is between the first end and about one-third of the length of the shaft from the first end towards the second end.

Abstract: The invention provides drill bits and methods of drilling curved boreholes. One aspect of the invention provides a drill bit including a bit body and one or more blades positioned within the bit body, the one or more blades individually actuatable to a plurality of cut depths. Another aspect of the invention provides a method for drilling a curved borehole. The method includes: providing a drill string including a drill bit including a bit body and one or more blades positioned within the bit body, the one or more blades individually actuatable to a plurality of cut depths; rotating the drill string; and selectively actuating the one or more blades to a plurality of cut depths; thereby drilling a curved borehole.

Abstract: A method for drilling a borehole in a producing subsea wellbore wherein a flexible conduit is connected at one end to a surface vessel and at the other end via a pressurized subsea wellhead to the producing wellbore such that a remotely operated electrical drilling device (RODD) can be deployed down the flexible conduit, the method comprising: directing a RODD to the location for drilling in the wellbore; and drilling a further wellbore section with the RODD; wherein the drilling comprises drilling in underbalanced conditions with respect to the formation; and using fluids produced from the formation to transport the drill cuttings away from the drilling device.

Abstract: A drilling system is presented for use in drilling lateral boreholes from a main borehole. The drilling system generally comprises a drilling machine, a drill string connected to the drilling machine so as to be driveable in an axial direction, and a guide connected to the drilling machine such that when the drill string is driven axially by the drilling machine, it interacts with the guide so as to be directed in a predetermined radial direction. A method of drilling a lateral borehole from a main borehole is also presented, comprising the steps of: positioning the drilling system in the main borehole; anchoring the guide in the borehole; operating the drilling machine to drive the drill string in an axial direction; and deflecting the drill string, by means of the guide, in a radial direction into the wall of the main borehole to drill the lateral borehole.

Abstract: A steerable system comprises a fluid powered motor 10 having a rotor 16 and a stator 18, and a bias arrangement having a plurality of bias pads 34 connected to the stator 18 so as to be rotatable therewith, the bias pads 34 being moveable to allow the application of a side load to the steerable system.

Abstract: A method for forming two or more wellbores in a subsurface formation includes forming a first wellbore in the formation. A second wellbore is directionally drilled in a selected relationship relative to the first wellbore. At least one magnetic field is provided in the second wellbore using one or more magnets in the second wellbore located on a drilling string used to drill the second wellbore. At least one magnetic field is sensed in the first wellbore using at least two sensors in the first wellbore as the magnetic field passes by the at least two sensors while the second wellbore is being drilled. A position of the second wellbore is continuously assessed relative to the first wellbore using the sensed magnetic field. The direction of drilling of the second wellbore is adjusted so that the second wellbore remains in the selected relationship relative to the first wellbore.

Abstract: An assembly and methods for constructing a MONOWELL include a monodiameter casing disposed in a monodiameter wellbore having diametric efficiency with a monobore production delivery system disposed within the monodiameter casing. An assembly for constructing a monodiameter wellbore includes a bottomhole assembly having a overgauge hole drilling member, a directional steering assembly, a measurement while drilling tool, and a logging while drilling tool; a work string attached to the bottomhole assembly and extending to the surface; drilling fluids flowing through the work string and bottomhole assembly; chemical casing casing the borehole; expandable casing disposed in the wellbore; and a sealing composition disposed between the expandable casing and the wellbore.

Abstract: A rotary steerable tool (2) for use in a downhole drilling apparatus for adjusting the direction of drilling is disclosed. The tool comprises a tubular outer housing (20) and a row of steering pushers (24) slidably mounted to the housing for movement between an extended position, in which the steering pusher engages a wall of a borehole formed by the drilling apparatus, and a withdrawn position, in which the steering pushers do not engage the wall of the borehole. A tubular sleeve (4) is mounted inside the housing (20) to transmit rotary drive to a drilling bit. A pressure chamber (22) defined between the sleeve (4) and the housing (20) communicates with the steering pushers (24) to move the steering pushers (24) to the extended position.

Abstract: A central slant hub tool is provided which is capable of receiving tubing or a tool such as a drill from the surface and directing the tube or tool laterally outward using an exit line slant surface or directing the tube or tool downward to an area below the tool. In this way, the tool acts as a hub to communicate with both lateral branches and lower zones of the main casing. Fracture window tools may be installed in the lateral and lower branches to selectively open the bores for drilling, testing and/or production or may be sealed by a bridge plug or the like when not in use.

Abstract: A method for forming multiple lateral boreholes from an existing wellbore is provided. The wellbore has been completed with a string of production casing. The wellbore may have a slimhole region having an inner diameter that is less than the inner diameter of the production casing. The method generally comprises providing a downhole apparatus having a whipstock. The whipstock may be a single piece tool that rotates into position below the slimhole region, or it may be a two piece tool comprising a top whipstock member and a separate bottom whipstock member. The whipstock has a curved face. The method also includes running the apparatus down into the parent wellbore. A force is applied to the apparatus to cause the whipstock to rotate within the wellbore into an operating position. In this position, the curved face of the whipstock forms a bend-radius that allows the jetting hose to bend across the entire inner diameter of the production casing. A jetting hose is run into the wellbore.

Abstract: A steerable drilling system includes a drill string carrying a bent housing, the bent housing containing or having associated therewith a drive motor arranged to drive a drive shaft angled to an axis of part of the drill string adjacent the bent housing, and an orientating motor permitting relative rotation between the drill string and the bent housing, the orientating motor driving the output shaft in a reverse direction relative to a direction of rotation of the drill string to form a curve in a borehole being formed.

Abstract: Multimodal geosteering systems and methods are disclosed. Some disclosed tool embodiments include first and second transmitter-receiver arrangements that make geosteering measurements using different forms of energy (such as acoustic and electromagnetic energy) to provide geosteering measurements that at least indicate a boundary direction but may also indicate a boundary distance. Some disclosed method embodiments include: determining a direction to a bed boundary using measurements with different energy types; and adjusting a drilling direction based at least in part on said determination. Combinations of (or selections between) the different measurements may be made based on, inter alia, measurement range, resolution, and contrast. Some disclosed system embodiments include a memory and a processor. The memory stores geosteering display software that configures the processor to generate an image with different regions based on the different types of geosteering measurements.

Abstract: A method for the directional control of a rock-drilling ma-chine, the drilling unit (1) of the rock-drilling machine, which is located in a borehole (2), comprising at least a pi-lot drill bit (6) or an underreamer drill bit (8), the drill bit(s) (6, 8) being driven by an electric motor (10) via a gearbox (12), and the drill bit(s) (6, 8) being moved into the rock (3) by means of a feeding rod (4) extending from a feeding machine at the outside the borehole (2), and the drill bit(s) (6, 8), gearbox (12) and motor (10) being pivoted in a controlled manner about a steering axis (18) which is approximately perpendicular to the center axis (26) of the feeding rod (4).

Abstract: The invention provides rotary steerable devices and methods for use of rotary steerable devices. One aspect of the invention provides a rotary steerable device including: a cylinder configured for rotation in a wellbore, the cylinder having a slot and a gauge; and at least one cam received in the slot. The cam is configured for selective actuation between a first position, wherein the cam lies within the gauge of the cylinder, and a second position, wherein the cam is displaced out of the gauge of the cylinder.

Abstract: A technique is used to control the direction of a drill bit or bottom hole assembly via hydraulic steering utilizing a plurality of steering pads. A portion of hydraulic fluid, e.g. drilling fluid, is directed under pressure to a pad interface region proximate each pad. The hydraulic fluid provides additional force against a surrounding wall and/or reduces or eliminates contact between the pads and the surrounding wall.

Abstract: Embodiments described herein comprise a system and method for controlling directional drilling. The system includes a conveyance for conveying a bottom hole assembly BHA into a wellbore. The BHA may include a bent housing, a drilling tool and a motor for rotating the bent housing in the wellbore. The system further includes a conveyance rotation device for rotating the conveyance in the opposite direction of the bent housing. The direction of the bent housing may be controlled by controlling the rotational speed of the bent housing and the conveyance while drilling.

Abstract: Bottom hole assemblies for cutting windows in wellbore casing comprise a window mill, a first upper mill, a second upper mill, and a third upper mill. The first mill has an outer diameter that is smaller than the outer diameters of the window mill and the second and third upper mills. The first upper mill is disposed above the window mill at a distance measuring approximately twenty to thirty-seven percent of the distance measured from the window mill to the third upper mill. The second upper mill is disposed above the window mill at a distance measuring approximately fifty-five to seventy-five percent of the distance measured from the window mill to the third upper mill. The third upper mill is disposed above the window mill at a distance measuring approximately one-hundred twenty to one-hundred thirty percent of the length of a ramp of a whipstock for guiding the mills.

Abstract: A method of steering a drill bit while drilling a wellbore can include periodically delivering an impact to the drill bit as the drill bit is rotated by a drill string. The impact may be delivered to the drill bit when an axis of the drill bit is oriented in a desired azimuthal direction relative to an axis of the drill string. Another method of steering a drill bit while drilling a wellbore may include interconnecting a bend in a drill string between an impact tool and the drill bit, and periodically delivering an impact from the impact tool to the drill bit as the drill bit is rotated by the drill string. A directional drilling system can include a drill string having a bend interconnected therein, an impact tool, and a drill bit, the bend being interconnected in the drill string between the drill bit and the impact tool.

Abstract: A sidetracking tool includes a setting tool having an expandable anchor, a whipstock connected to an upper end of the setting tool, the whipstock having a ramp face along an axial length thereof, and a drilling assembly including a drill bit disposed on an end thereof, wherein the drill bit is configured to interface with the ramp face of the whipstock.

Abstract: A method of steering a drill bit while drilling a wellbore can include periodically increasing a rotational speed of the drill bit while drilling the wellbore, with the rotational speed being increased when an axis of the drill bit is oriented in a desired azimuthal direction relative to a drill string axis. A directional drilling system can include a drill string having a bend interconnected therein, a drill bit, and a controller which selectively increases a rotational speed of the drill bit when an axis of the drill bit is oriented in a desired azimuthal direction relative to an axis of the drill string above the bend. Another method of steering a drill bit while drilling a wellbore can include interconnecting a brake in a drill string, and periodically decreasing a braking force of the brake as the drill bit is rotated.

Abstract: A drill string having a drill bit with a bit body located between a shank and a working face. The working face has at least one cutting element and a jack element disposed partially within the drill bit body and partially protruding from the working face. The jack element is adapted to be rotated with respect to the bit body by a driving mechanism disposed within a bore of the drill string. A generator or motor with a rotor is incorporated into a torque transmitting mechanism that links the driving mechanism to the jack element, and configured so that at least one waveform is produced in the generator or motor when the jack element is rotated. The waveform is processed by an electronic processing device to determine the rotational position of the jack element.

Abstract: Aspects of this invention include a downhole tool and method for making a physical caliper measurement of a subterranean borehole. The tool is configured to make the physical borehole caliper measurement only when the measured pressure in each of three or more outwardly extendable blades is greater than a predetermined threshold pressure. Blade positions are measured and the borehole caliper calculated only when the pressure in each of the blades exceeds the threshold. Exemplary embodiments of the invention enable physical caliper measurements to be made with increased accuracy with each of the blades making firm contact with the borehole wall. Methods in accordance with the invention are especially well suited for use in directional drilling applications in that they tend to enable accurate caliper measurements to be made without repositioning the steering tool in the borehole.

Abstract: A tracking receiver system is used to track the progress of a downhole tool along a subsurface path having a desired grade. The tracking receiver system is adapted to detect a reference line originating from a reference line receiver and to determine the position of the downhole tool along a desired subsurface path relative to the reference line. In an alternative embodiment the tracking receiver system may comprise a global positioning satellite system to provide information used to determine the position of the downhole tool relative to the desired subsurface path.

Abstract: In a method for the trenchless laying of pipes, a drilling operation (5) is firstly carried out by means of controlled heading from a starting point (1) to a finishing point (6). Then the drilling head (3) is disconnected from the heading pipes (4) and the heading pipe run is connected by means of a special connecting pipe to the product pipe run (9), which is prefabricated above ground at the finishing point (6). Subsequently, the heading pipes (4) are drawn back from the drill hole to the starting point (1), the product pipe run (9) simultaneously being drawn into the drill hole.

Abstract: The present invention recites a method, system and apparatus for steering a drill string, wherein an eccentric steering device is recited. The eccentric steering device may comprise an eccentric sleeve configured for mounting exterior to a portion of the drill string and permitting the drill string to rotate within the eccentric sleeve and a brake positioned to selectively cause rotation of the eccentric sleeve with the drill string. In one embodiment, the eccentric steering device may further comprise one or more bearings positioned between the eccentric sleeve and the drill string.

Abstract: The present invention recites a method, system and apparatus, wherein said method, system and apparatus comprises a gauge pad for a rotary component received within a borehole, the gauge pad comprising an exterior surface dimensioned for rotation in close proximity to the borehole, a pocket extending through the exterior surface, the pocket in fluid communication with a pressurized fluid source, and wherein the exterior surface is dimensioned such that when a pressurized fluid is discharged through the pocket, the velocity of the fluid through a gap between the exterior surface and borehole creates a pressure drop sufficient to pull the rotary component toward the gauge pad.

Abstract: The present invention recites a method and apparatus, wherein said methods and apparatus comprises an actuator comprising a first plate, a pocket extending through the first plate, the pocket in fluid communication with a pressurized fluid source and a second plate coupled to a component that is to be actuated, wherein the first plate, the second plate, and the pocket are dimensioned such that when a pressurized fluid is discharged through the pocket, the velocity of the fluid through a gap between the first plate and the second plate creates a pressure drop sufficient to pull the second plate toward the first plate.

Abstract: A method of steering a drilling operation of a well using acoustic measurements. The method includes obtaining, using a central processing unit (CPU), a clean-wet matrix line for the well, where the clean-wet matrix line includes a number of normal compressional values, obtaining, using the CPU, the acoustic measurements from at least one logging while drilling tool at a current depth of the drilling operation, where the acoustic measurements include a compressional to shear velocity ratio and a delta-T compressional measurement, and determining, using the CPU, a current phase of the drilling operation by comparing the acoustic measurements to the clean-wet matrix line. The method further includes, in response to determining that the current phase is not a target phase, generating an updated well trajectory for steering the drilling operation toward the target phase and adjusting the drilling operation using the updated well trajectory.

Abstract: A direction adjustment tool for a downhole drilling apparatus is disclosed. The tool has a tubular housing adapted to be incorporated into a downhole drilling apparatus, and steering blades mounted to the housing. A drive shaft transmits drive to a drill bit of a drilling apparatus, wherein the shaft defines a passage for transmitting drilling fluid to the drill bit. A first pressure chamber is defined between the housing and the shaft and communicates with the passage, wherein the steering blades are moved from retracted positions to extended positions thereof as a result of increase of fluid pressure the first pressure chamber. A pendulum member is pivotably mounted to extend in a vertical orientation when the shaft is not rotating relative to the housing, and pistons prevent movement of at least one steering blade to the extended position thereof as a result of the angle between a longitudinal axis of the shaft and the longitudinal axis of the pendulum member exceeding a predetermined amount.

Abstract: A steering tool configured for making azimuthal and non-azimuthal formation evaluation measurements is disclosed. In one embodiment a rotary steerable tool includes at least one formation evaluation sensor deployed in the steering tool housing. The steering tool may include, for example, first and second circumferentially opposed formation evaluation sensors or first, second, and third formation evaluation sensors, each of which is radially offset and circumferentially aligned with a corresponding one of the steering tool blades. The invention further includes methods for geosteering in which a rotation rate of the steering tool housing in the borehole (and therefore the rotation rate of the formation evaluation sensors) is controlled. Steering decisions may be made utilizing the formation evaluation measurements and/or derived borehole images.

Abstract: A directional drilling system, a drilling hammer and a fluid flow telemetry modulator use a plurality of magnets arranged to convert rotational motion into reciprocating linear motion. Various types of motor can provide rotational motion to a part of the magnets and various linkages and other devices can cause steering or operation of a modulator valve. A torsional drilling hammer uses a plurality of magnets arranged to convert reciprocating linear motion into reciprocating rotational motion. A motor and linkage drives the linearly moving part of the magnets, and the rotating part provides torsional impact be striking the linearly moving part of the magnets.

Abstract: A bottom hole assembly (BHA) for use in drilling a wellbore includes: a first mud motor having a stator and a rotor; a second mud motor having a stator and a rotor; a drill bit rotationally coupled to the second rotor and having a tool face and a longitudinal axis inclined relative to a longitudinal axis of the first mud motor; and a clutch. The clutch is operable to: rotationally couple the second stator to the first stator in a first mode at a first orientation of the tool face, rotationally couple the first rotor to the second stator in a second mode, change the first orientation to a second orientation by a predetermined increment, orient the tool face at the second orientation in an orienting mode, and shift among the modes in response to a change in flow rate of a fluid injected through the clutch and/or a change in weight exerted on the drill bit.

Abstract: A system for drilling a lateral hole departing from a main well. The system comprises a motor assembly (415) including a motor (412) to generate a rotating torque, an axial thruster (411) to generate an axial force, a blocking system (410) to fix the motor and the axial thruster downhole. The motor assembly further includes a drive shaft (414) to transmit the rotating torque. The system further comprises a first and second connector (402, 404) for transmitting the rotating torque and the axial force from the motor assembly to a drill string assembly. The first connector is connectable to the drill string assembly so as to transmit the axial force only to the drill pipe (401), and to transmit the rotating torque to a further drive (405) shaft positioned within the drill pipe. The second connector (402) is connectable to the drill string assembly so as to transmit both the axial force and the rotating torque to the drill pipe (401).

Abstract: A borehole network including first and second end surface locations and at least one intermediate surface location interconnected by a subterranean path, and a method for connecting a subterranean path between a first borehole including a directional section and a second borehole including a directional section. A directional drilling component is drilled in at least one of the directional sections to obtain a required proximity between the first and second boreholes. An intersecting component is drilled, utilizing magnetic ranging techniques, from one directional section to provide a borehole intersection between the first and second boreholes, thereby connecting the subterranean path.

Abstract: A non-rotating downhole sleeve adapted for open hole drilling and/or casing centralization. The sleeve includes a tubular body made of hard plastic with integrally formed helical blades positioned around its outer surface and an inner surface configuration which allows drilling fluid circulation to form a non-rotating fluid bearing between the sleeve and the drill pipe or casing. The helical blades reduce sliding and rotating torque while drilling, with minimal obstruction to drilling fluid passing through the borehole between the blades. In one embodiment, improvements are provided during casing exit when drilling in open hole environments. In another embodiment, improvements are provided in the sleeve's resistance to compressive loading.

Abstract: A steerable drilling system comprises a rotary drill bit 14 secured to a housing 16, a secondary rotary drill component 22 carried by the housing and rotatable therewith, the second rotary drill component 22 having a gauge dimension greater than that of the rotary drill bit 14, and a drive arrangement operable to displace the secondary rotary drill component 22 relative to the housing 16 while maintaining an axis 24 of the secondary rotary drill component 22 substantially parallel to an axis 18 of the housing 16.

Abstract: Hydrostatic bearings are used for drill string stabilization and bottom hole assembly steering. The hydrostatic bearings utilize an existing mud flow as the bearing fluid. For steering, the bearings may be used between movable kick pads and the formation to reduce friction. Alternatively, differential hydrostatic bearing pressure may be utilized to steer. Multi-modal (non-linear and linear) steering may be provided by selectively applying equal and unequal hydrostatic bearing pressures. The bearings can be made more tolerant of imperfections in the formation by utilizing multiple pressure pockets.

Abstract: A method for trenchless pipe laying, a pipeline is constructed form a starting point to a goal point undercrossing an obstacle wherein the constructing of a bore hole and laying the prefabricated pipeline, which is constructed in one piece on the surface, are done in one work step, wherein at the front end of the pipeline a steerable drilling device is arranged, wherein a pipe thrusting device is arranged at the starting point applying forces from the outside to the pipeline via traction preferably friction by pushing the pipeline from a starting point to a goal point, wherein at the same time the necessary contact forces for drilling are transferred, wherein the cuttings produced during the drilling by the drilling device are removed and transported hydraulically out of the bore hole via a transport line inside the pipeline, and wherein the annular space between pipeline and bore hole wall created during drilling is continuously filled with a drilling suspension.

Abstract: Disclosed herein is a system for steering the direction of a borehole advanced by cutting action of a rotary drill bit by periodically varying action of a drill bit while continuously rotating a drill string to which the drill bit is operationally attached. The steering system can include a bit perturbation device cooperating with a bent housing subsection and operationally connected to the drill string and to the drill bit. Drill bit action can be varied by periodically varying the rotation speed and/or rate of penetration of the drill bit. Periodic drill bit action results in preferential cutting of material from a predetermined arc of the borehole wall which, in turn, results in borehole deviation. Action of the drill bit can be varied independently of the rotation rate of the drill string.