WO2010107606A2 - Système et procédé de forage dirigé comprenant une rotation inverse continue - Google Patents

Système et procédé de forage dirigé comprenant une rotation inverse continue Download PDF

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Publication number
WO2010107606A2
WO2010107606A2 PCT/US2010/026524 US2010026524W WO2010107606A2 WO 2010107606 A2 WO2010107606 A2 WO 2010107606A2 US 2010026524 W US2010026524 W US 2010026524W WO 2010107606 A2 WO2010107606 A2 WO 2010107606A2
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WO
WIPO (PCT)
Prior art keywords
proximal
distal
housing
drill string
borehole
Prior art date
Application number
PCT/US2010/026524
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English (en)
Other versions
WO2010107606A3 (fr
Inventor
Louis C. Hartke
Tod Jason Michael
Original Assignee
Vermeer Manufacturing Company
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Vermeer Manufacturing Company filed Critical Vermeer Manufacturing Company
Publication of WO2010107606A2 publication Critical patent/WO2010107606A2/fr
Publication of WO2010107606A3 publication Critical patent/WO2010107606A3/fr

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Classifications

    • E—FIXED CONSTRUCTIONS
    • E21—EARTH OR ROCK DRILLING; MINING
    • E21B—EARTH OR ROCK DRILLING; OBTAINING OIL, GAS, WATER, SOLUBLE OR MELTABLE MATERIALS OR A SLURRY OF MINERALS FROM WELLS
    • E21B7/00—Special methods or apparatus for drilling
    • E21B7/04—Directional drilling
    • E21B7/06—Deflecting the direction of boreholes
    • E21B7/067—Deflecting the direction of boreholes with means for locking sections of a pipe or of a guide for a shaft in angular relation, e.g. adjustable bent sub

Definitions

  • This invention generally relates to a boring system for directional drilling including horizontal drilling; and more specifically to a device and method of boring through a variety of soil types ranging from compressible soils to hard rock.
  • Mud motor technology utilizes drilling fluid to transfer power from a drill rig located at a ground surface, through a drill string comprised of interconnected drill rods, to a down-hole motor.
  • the drill string is connected to the rear end of the mud motor; while a drill bit, attached to an output shaft, is connected to a front end of the mud motor.
  • the drill bit is powered rotationally by torque generated by drilling fluid passing through the motor. The drill bit can thus be rotated, while the drill string is held from rotating.
  • Directional control is achieved by the addition of an offset coupling that offsets the center-line of the drill bit from the center-line of the drill string and mud motor.
  • an offset coupling that offsets the center-line of the drill bit from the center-line of the drill string and mud motor.
  • the drill string is held from rotating, and the drill bit rotated by the mud motor.
  • the drill string then moves the assembly longitudinally forward, creating a bored hole in the direction of the centerline of the drill bit.
  • To bore a straight hole the drill string, mud motor, and offset coupling are all rotated to create a bored hole in the direction of the centerline of the adjacent drill string.
  • mud motors One limitation of mud motors is related to the capacity to transmit power to the drill bit. Since the drill string is not rotationally secured to the drill bit, the mud motor must provide the rotational power to the bit. The length of the motor is typically a function of the rotational power provided to the bit. In some applications, the length required to develop sufficient torque is significant. Further, the construction of mud motors is such that they are typically less flexible than the drill rod. This combination of length and stiffness can limit the directional control capability of mud motor systems.
  • a second inherent limitation of mud motors is related to the use of the drilling fluid to provide rotational power to the drill bit. Since mud flow rate and pressure determine the power transferred to the drill bit, the rate and pressure must be maintained in order to maintain drilling speed. In some situations, other aspects of drilling are affected by the flow rate of the drilling mud, and it may be desirable to reduce either the flow rate or the pressure. These situations compromise the efficiencies of the contrasting aspects of a drilling operation. For instance, a "frac- out" can occur as a result of excessive flow or excessive pressure of the drilling fluid. A frac-out situation is where drilling fluid is forced though a fracture in the ground rather than through the bored hole. In a frac-out situation, it is desirable to reduce flow rate or fluid pressure to cease further expansion of the ground facture.
  • the flow rate and pressure are at an initially reduced level to prevent the probability of a frac-out altogether.
  • reducing the flow rate and pressure negatively affects drilling performance.
  • a third inherent limitation is related to the need for the drill bit to be offset from the centerline of the mud motor. This offset requires a complicated drive shaft assembly in order to transfer the rotary power through the offset.
  • the drill bit is mounted to the drive shaft, which is inherently more flexible than the motor housing.
  • the resulting assembly has several limitations including significant initial cost associated with the complicated assembly, limited durability, and a flexibility that can affect the dynamic stability of the drill bit during drilling.
  • pipe-in-pipe technology operates in a similar fashion.
  • the drill bit is oriented at an end of an outer drill string with a center that is offset with respect to the center of the outer drill string.
  • An inner pipe rotationally powers the drill bit independent from rotation of the outer drill string.
  • the outer drill string is held from rotating while the inner drill pipe rotates the drill bit.
  • the drill string is then moved forward to create a bored hole in the direction of the offset.
  • To bore a straight hole the outer drill string, the inner drip pipe and the drill bit are all rotated to create a bored hole in the direction of the centerline of the outer drill string.
  • One limitation of this technology relates to the size of the component that provides rotational power to the drill bit, i.e., the inner pipe. Because the diameter of the inner pipe is smaller that the outer drill string, the maximum torque that can be transferred to the drill bit is less than the maximum torque that could be transferred by the outer drill string.
  • a second limitation of pipe-in-pipe technology is related to the inherent flow restriction of the pipe-in-pipe configuration. Drilling fluid is required to cool the drill bit and to transfer the cuttings out of the bored hole. The rate of drilling can be limited by the fluid flow rate.
  • the cross-sectional area of the inner drill pipe, which is used to transfer the fluid, is less than the cross-sectional area of the outer drill string. Thus, the maximum flow rate is lower, or the fluid pressure at the drill rig is higher for a given flow rate, with a pipe-in-pipe system as compared to other systems utilizing the outer drill string for fluid transfer.
  • Rotary steerable devices include a down-hole housing mounted on the drill string on bearings such that the housing can remain stationary while the drill string rotates.
  • a drill bit is powered rotationally by an extension of the drill string and a drive shaft that extends through the down-hole housing.
  • the down-hole housing has an offset to subject the drill bit to an unbalanced load condition, causing it to change the direction of the borehole.
  • the orientation of the down-hole housing determines the boring direction of drill bit.
  • a limitation of rotary steerable devices is related to the fact that there is a non-fixed relationship between the down-hole housing and the drill string.
  • Many designs have been developed to control of the position of the housing relative to the drill string. Typically the designs involve manipulating the drill string. Any change in orientation of the down-hole housing in relation to the drill string during general operation will affect the direction of the bored hole. Changes in orientation of the housing relative to the drill string are unpredictable making operation complicated and the results unreliable.
  • Hammer technology utilizes drilling fluid to transfer power from the drill rig at the surface, through a drill string comprised of inter-connected drill rods, to a down-hole hammer.
  • the drill string is connected to a rear end of the hammer.
  • a drill bit, attached to an output shaft of the hammer, is connected at a front-end of the hammer.
  • the drill bit is powered longitudinally with impact impulses from the hammer.
  • the drill bit is able to cut through hard materials such as rock, without requiring full rotation of the drill bit.
  • the drill string is oscillated rather than rotated.
  • the drill string can be oscillated slightly while the drill bit is cutting with the impact impulses generated by the fluid activated hammer to control the direction of boring.
  • the drill bit is oriented in manner such that an effective center of the bit is offset from the center of the drill string while the drill string is moved forward.
  • the drill string, the hammer, and the drill bit are all rotated to create a bored hole in the direction of the centerline of the drill string.
  • a limitation of the hammer technology is related to the capability of the drilling fluid, used with currently available hammers, to carry cuttings.
  • Commercially available hammers useful for this type of horizontal boring are activated with compressed air.
  • the capability of compressed air to carry and transport sizable cuttings is less than the capability of drill mud used with either mud motors or pipe-in-pipe technology.
  • the maximum length of a bored hole is limited by the capability of the fluid to transfer the cuttings a particular distance.
  • the deviated drilling mode can be used for steering the drill bit and the attached drill string and thereby bore a curved hole.
  • a one-way clutch is connected between the drill string and the drill bit. In the straight drilling mode, the one-way clutch continuously transfers the continuous rotation in the first direction of the drill string to the drill bit, and, in the deviated drilling mode, the one-way clutch essentially transfers only the drill string's rotation in the first direction to the drill bit. While the drill string is rotating in the second direction, essentially no rotation is transferred by the one-way clutch from the drill string to the drill bit.
  • a limitation of the oscillating drill string technology is related to interrupted motion (e.g., a cyclical rotational velocity profile and/or cyclical starts and stops) of the drill bit when in the deviated drilling mode.
  • interrupted motion e.g., a cyclical rotational velocity profile and/or cyclical starts and stops
  • This limitation can reduce boring productivity while in the deviated drilling mode as compared to the straight drilling mode.
  • Continuous rotational motion at the drill bit can be more productive than interrupted rotational motion.
  • the present disclosure relates to a drilling arrangement for drilling a borehole in earth, a proximal end of the drilling arrangement is preferably connected to a drill string of a drilling machine and a distal end of the drilling arrangement is preferably connected to a drill bit.
  • the drilling arrangement preferably includes a driveline, rotationally connecting the drill string to the drill bit, a steering housing, connected to the driveline by a one-way clutch, and means to longitudinally connect the drill string to the drill bit.
  • the borehole is typically extended by rotating the drill bit while longitudinally thrusting the drill bit in a distal direction thus creating newly formed borehole.
  • the drilling machine typically applies rotational torque and longitudinal thrust via the drill string to the drilling arrangement and thereby to the drill bit.
  • the drilling machine advances the drill string, and thereby the drilling arrangement and the drill bit, farther into the borehole.
  • Biasing features, included on the steering housing promote angular deviation of the newly formed borehole thus angularly offsetting the newly formed borehole from the adjacent drill string in a biasing direction.
  • Geometry of the biasing features of the steering housing can be selected to relate the steering housing's longitudinal orientation in the borehole to the biasing direction.
  • Straight segments of the borehole can be produced by continuously rotating the drill string, and thereby the driveline, in a first rotational direction such that the one-way clutch rotationally engages the steering housing with the driveline.
  • the steering housing is thereby continuously rotated in the first rotational direction.
  • the drill bit, rotationally connected to the drill string by the driveline is also thereby continuously rotated with the drill string in the first rotational direction.
  • the biasing direction is continuously rotated, thus preventing significant accumulation of the angular deviation in any one direction in the newly formed borehole.
  • the angular deviation, encouraged by the biasing features of the steering housing is thus circumferentially distributed around the newly formed borehole as the drill bit advances resulting in the newly formed borehole being substantially straight.
  • Curved segments of the borehole can be produced by rotating the drill string in a second rotational direction, opposite the first rotational direction, such that the one-way clutch disengages the steering housing from the driveline.
  • the drill bit rotationally connected to the drill string by the driveline, is continuously rotated with the drill string in the second rotational direction.
  • the disengaged steering housing is typically held from rotating by friction with the borehole, and thus the biasing features of the steering housing typically maintain a consistent longitudinal orientation within the borehole as the drill bit advances.
  • the angular deviation, encouraged by the biasing features of the steering housing is thus directed at a given circumferential position of the borehole.
  • the angular deviation of the newly formed borehole accumulates in the biasing direction thus forming the curved segment along the biasing direction and resulting in a direction of curvature of the newly formed borehole.
  • the biasing direction can be adjusted and/or selected from time-to- time by rotating the drill string in the first rotational direction, thus longitudinally rotating the steering housing.
  • the drill string rotation is stopped thus setting a selected the biasing direction.
  • the direction of curvature of the newly formed borehole is in the selected biasing direction.
  • the steering housing includes a proximal housing end positioned opposite from a distal housing end.
  • the proximal housing end is spaced longitudinally from the distal housing end.
  • the proximal housing end defines a proximal axis, and the distal housing end defines a distal axis.
  • the driveline extends through the steering housing and includes an input drive connection that is rotationally connected with a drill bit receiver.
  • the input drive connection is positioned adjacent the proximal housing end and is rotatably mounted about the proximal axis.
  • the drill bit receiver is positioned adjacent the distal housing end and is rotatably mounted about the distal axis.
  • the input drive connection is adapted for connection with the drill string, and the drill bit receiver is adapted for connection with the drill bit.
  • the driveline further includes a slidable connection (e.g., a splined connection) between the input drive connection and the drill bit receiver.
  • the one-way clutch includes a first rotational element and a second rotational element.
  • the first rotational element is rotationally connected with the steering housing
  • the second rotational element is rotationally connected with the driveline.
  • the steering housing When the input drive connection of the driveline is rotated in the first rotational direction relative to the earth, the steering housing also rotates in the first rotational direction.
  • the steering housing When the input drive connection of the driveline is rotated in the second rotational direction, the steering housing does not necessarily rotate with the input drive connection.
  • a relative rotational movement is defined between the first and the second rotational elements of the one-way clutch.
  • the first and the second rotational elements transmit substantial torque between each other when the relative rotational movement between the first and the second rotational elements occurs in a first relative direction and comparatively little or no torque is transmitted when the relative rotational movement occurs in a second relative direction that is opposite the first relative direction.
  • the drilling arrangement can include a position transmitter mounted on a position transmitter mount included on the steering housing between the proximal and the distal housing ends.
  • the proximal axis of the proximal housing end and the distal axis of the distal housing end are aligned.
  • an offset angle is defined between the proximal axis of the proximal housing end and the distal axis of the distal housing end.
  • the driveline further includes an angularly offsettable element (e.g., a universal joint and/or a flexible shaft segment) between the input drive connection and the drill bit receiver.
  • a proximal bearing is rotationally aligned with the proximal axis and is mounted at the proximal housing end.
  • a distal bearing is rotationally aligned with the distal axis and is mounted at the distal housing end.
  • Longitudinal loads can be transferred through the drilling arrangement along a longitudinal load path consecutively including the input drive connection of the driveline, the proximal bearing, the steering housing, the distal bearing, and the drill bit receiver of the driveline.
  • the input drive connection, the proximal bearing, the steering housing, the distal bearing, and the drill bit receiver of the drilling arrangement thus provide an example means to longitudinally connect the drill string to the drill bit and thus transfer the longitudinal thrust from the drill string to the drill bit.
  • the drilling arrangement can further include a proximal cap and a distal cap
  • the steering housing can include a proximal segment, a central segment, and a distal segment.
  • the proximal cap can be fixedly connected to the proximal segment; the proximal segment can be fixedly connected to the central segment; the central segment can be fixedly connected to the distal segment; and the distal segment can be fixedly connected to the distal cap.
  • the proximal bearing is retained within the proximal segment of the steering housing by the proximal cap and the distal bearing is retained within the distal segment of the steering housing by the distal cap.
  • a splineless driveline can directly connect and transfer both thrust and torque from the drill string to the drill bit.
  • the present disclosure also relates to a method of using a boring head (e.g., the drilling arrangement) attached to the drill string for drilling the borehole in the earth and for steering the borehole along a desired path.
  • the method includes: Mount the boring head to the drill string and connect the drill bit to the boring head.
  • the above method can further include:
  • the position transmitter preferably mounted within the steering housing and a receiver positioned above the earth can be used to monitor the position and the rotational orientation of the steering housing.
  • certain requirements of the drill rig are not changed from those of a standard drill rig, allowing the present invention to be utilized with standard drill rigs after retrofitting the standard drill rigs.
  • Figure 1 is a side elevation view, showing above and below ground- level, including a typical horizontal directional drilling environment of the present disclosure
  • Figure 2 is an isometric view illustrating a first example embodiment of a boring head of the present disclosure
  • Figure 3 is a side elevation view of the boring head of Figure 2;
  • Figure 4 is a top plan view of the boring head of Figure 2;
  • Figure 5 is a view along an axis of rotation of a drive input of the boring head of Figure 2 showing the drive input;
  • Figure 6 is a view along an axis of rotation of a drill bit holder of the boring head of Figure 2 showing the drill bit holder;
  • Figure 7 is a bottom plan view of the boring head of Figure 2;
  • Figure 8 is an exploded isometric view of the boring head of Figure 2;
  • Figure 9 is Figure 8 in vertical cross-section;
  • Figure 10 is another exploded isometric view in vertical cross-section of the boring head of Figure 2;
  • Figure 11 is a cross-sectional side elevation view of the boring head of Figure 2;
  • Figure 12 is an enlarged portion of Figure 11;
  • Figure 13 is an enlarged portion of Figure 11 ;
  • Figure 14 is an enlarged portion of Figure 11 ;
  • Figure 15 is Figure 2 in vertical cross-section
  • Figure 16 is an enlarged portion of Figure 15;
  • Figure 17 is an enlarged portion of Figure 15;
  • Figure 18 is an enlarged portion of Figure 15 ;
  • Figures 19, 20, and 21 are schematic side views illustrating possible drill bit configurations that can be implemented with the boring heads of the present disclosure
  • Figure 22 is an isometric view illustrating a second example embodiment of a boring head of the present disclosure.
  • Figure 23 is a side elevation view of the boring head of Figure 22;
  • Figure 24 is a top plan view of the boring head of Figure 22;
  • Figure 25 is a view along an axis of rotation of a drill bit holder of the boring head of Figure 22 showing a drive input;
  • Figure 26 is a view along the axis of rotation of the drill bit holder of
  • Figure 27 is a bottom plan view of the boring head of Figure 22;
  • Figure 28 is an exploded isometric view of the boring head of Figure 22;
  • Figure 29 is Figure 28 in vertical cross-section;
  • Figure 30 is another exploded isometric view in vertical cross-section of the boring head of Figure 22;
  • Figure 31 is a cross-sectional side elevation view of the boring head of Figure 22;
  • Figure 32 is an enlarged portion of Figure 31;
  • Figure 33 is an enlarged portion of Figure 31;
  • Figure 34 is an enlarged portion of Figure 31;
  • Figure 35 is still another isometric view of the boring head of Figure 22 in vertical cross-section
  • Figure 36 is an enlarged portion of Figure 35;
  • Figure 37 is an enlarged portion of Figure 35;
  • Figure 38 is an enlarged portion of Figure 35;
  • Figure 39 is an isometric view of an example shaft joint enabling an angular offset between an axis of rotation of the drive input and the axis of rotation of the drill bit holder of the boring head of Figure 22;
  • Figure 40 is Figure 39 in vertical cross-section
  • Figure 41 is an exploded isometric view of the shaft joint of Figure 39;
  • Figure 42 is Figure 41 in vertical cross-section;
  • Figure 43 is an exploded isometric view illustrating a locking collar and a locking collar keeper for preventing a threaded joint from unscrewing;
  • Figure 44 is an isometric view illustrating the threaded joint, the locking collar, and the locking collar keeper of Figure 43, wherein the threaded joint is connected and the locking collar and the locking collar keeper are disengaged;
  • Figure 45 is Figure 44 in vertical cross-section
  • Figure 46 is an isometric view illustrating the threaded joint, the locking collar, and the locking collar keeper of Figure 43, wherein the threaded joint is connected and the locking collar and the locking collar keeper are engaged; and
  • Figure 47 is an example flow chart of a method whereby a borehole is drilled along a desired path by selectively rotating a drill string, connected to a boring head, in a first and a second direction.
  • the present disclosure relates to a boring head 100 for drilling a borehole 50 in earth.
  • the boring head 100 includes means for drilling straight and curved segments of the borehole 50 and for selecting a direction of curvature in which the curved segments are bored.
  • the boring head 100 is preferably connected at a proximal end 103 to a drill string 20 of a drilling machine 10 and mounts a drill bit at a distal end 105.
  • the boring head 100 preferably includes a driveline, rotationally connecting the drill string 20 to the drill bit, and a steering housing 30, connected to the driveline by a one-way clutch 115. Biasing features 38, included on the steering housing 30, promote angular deviation and thus angularly offset newly formed borehole in a biasing direction.
  • the straight segments of the borehole 50 can be produced by continuously rotating the drill string 20 in a first rotational direction causing the oneway clutch 115 to rotationally engage and continuously rotate the steering housing 30.
  • the biasing direction is thus continuously rotated which prevents significant accumulation of the angular deviation in any one direction in the newly formed borehole. This results in the newly formed borehole being substantially straight.
  • the curved segments of the borehole 50 can be produced by rotating the drill string 20 in a second rotational direction, opposite the first rotational direction, causing the one-way clutch 115 to disengage the steering housing 30.
  • the disengaged steering housing 30 is typically held from rotating by friction with the borehole 50 thus maintaining the biasing features 38 of the steering housing 30 in a consistent longitudinal orientation as the drill bit advances.
  • the angular deviation, encouraged by the biasing features 38 of the steering housing 30, is thus directed and accumulates at a given circumferential position of the borehole 50 resulting in curvature of the newly formed borehole.
  • the biasing direction can be adjusted and/or selected from time-to- time by rotating the drill string 20, and thereby the steering housing 30, in the first rotational direction. Upon the steering housing 30 reaching a desired longitudinal orientation, the drill string 20 rotation is stopped thus setting the biasing direction.
  • Example embodiments of the present disclosure are illustrated in the figures.
  • Figure 1 illustrates the drilling machine or rig 10 typically positioned at an above ground surface location, connected to and driving the drill string 20 that extends to the boring head 100.
  • the drilling rig 10 is typically capable of rotating the drill string 20, in a clockwise and a counterclockwise rotational direction, and also is capable of both forcing the drill string 20 longitudinally away from and pulling the drill string 20 back towards the drilling rig 10.
  • Pushing the drill string 20 away from the drilling rig 10, which will be referred to herein as thrust, is typically done by extending a length of the drill string 20. Extending the length of the drill string 20 can also create and/or extend the bored hole 50 below the ground surface.
  • the drilling rig 10 is likewise capable of pulling the drill string 20 back towards the drilling rig 10, which will be referred to herein as pull-back. Pulling the drill string 20 back towards the drilling rig 10 is typically done by shortening the drill string 20. Pulling the drill string 20 back towards the drilling rig 10 can be used to backream the bored hole 50.
  • the drilling rig 10 is normally used to form the bored hole 50 beginning at an entry point 52, extending through the ground along a planned route 60, avoiding underground obstacles, and terminating at an exit point. During operation, the drilling rig 10 rotates and pushes the drill string 20 and thereby the boring head 100 into contact with the ground.
  • the drilling/boring operation includes two basic types of steering or drilling modes: straight and deviated. In the straight mode, the bored hole 50 is extended in a direction parallel and coaxial with a longitudinal axis of the drill string 20 and typically extends straight, forming a straight segment of the bored hole 50. In the deviated mode, the bored hole 50 is extended in a direction that is angled from the longitudinal axis of the drill string 20.
  • the extending direction of the bored hole 50 may be angled or deviated relative to the longitudinal axis of the drill string 20 in an upward direction (known as a 12:00 direction), a downward direction (known as a 6:00 direction), a leftward direction (known as a 9:00 direction), or a rightward direction (known as a 3:00 direction).
  • a downward direction known as a 6:00 direction
  • a leftward direction known as a 9:00 direction
  • a rightward direction known as a 3:00 direction.
  • electronic and/or electromagnetic detection system(s) e.g., a receiver 780 and a sonde
  • operator(s) and/or control systems can selectively direct the drilling/boring operation and form the bored hole 50 along the planned route 60.
  • the drill string 20 typically follows and is positioned within the bored hole 50.
  • Segments of the bored hole 50 formed with the drilling rig 10 operating in the deviated mode are typically curved.
  • the drill string 20 follows such curved segments by bending across certain portions of its 20 length.
  • the bending across the certain portions is elastic and/or results in stresses below fatigue endurance limit(s) of material(s) of the drill string 20.
  • various portions of its 20 length can move between existing straight and curved segments of the bored hole 50.
  • the example boring head 100 operates in the straight mode when an input drive shaft 142 (see Figures 2 and 9) of the boring head 100 is rotated in a first rotational direction and operates in the deviated mode when the input drive shaft 142 is rotated in a second rotational direction.
  • the input drive shaft 142 can be rotated in the first and the second rotational directions by various means known in the art (e.g., as disclosed in U.S. Patent No. 6,357,537, issued March 19, 2002, and 6,491,115, issued December 10, 2002, which are hereby incorporated by reference in their entirety).
  • the drilling rig 10 rotates and thrusts the drill string 20, and the drill string 20 thereby rotates and thrusts the input drive shaft 142 of the boring head 100.
  • the rotational direction of the input drive shaft 142 can be switched at various intervals during the drilling/boring operation between the first and the second rotational directions thereby switching the drilling mode between the straight and the deviated modes. As further described hereinafter, by choosing the one-way clutch 115
  • the first rotational direction can be chosen to be a clockwise direction and the second rotational direction can be chosen to be a counterclockwise direction.
  • the first rotational direction can be chosen to be the counterclockwise direction and the second rotational direction can be chosen to be the clockwise direction.
  • the extending direction of the bored hole 50 is curved.
  • the extending direction of the bored hole 50 can be steered (e.g., the 12:00, the 6:00, the 9:00, and the 3:00 directions).
  • the direction of curvature is controllable by rotating the input drive shaft 142 of the boring head 100 in the first rotational direction and stopping the input drive shaft 142 at a certain selected position thereby orienting the steering housing 30 (see Figures 2, 8, and 9) of the boring head 100 in a selected orientation.
  • the direction of curvature of the bored hole 50 will correspond to the selected orientation of the steering housing 30.
  • drilling/boring in the deviated mode can be suspended, and the steering housing 30 can be reoriented by again rotating the input drive shaft 142 in the first rotational direction, stopping it 142 at a selected position.
  • a product such as a water line or an electrical cable, can be attached to the drill string 20 at the exit point and pulled back through the bored hole 50.
  • the size of the bored hole 50 can be enlarged, as necessary, to provide adequate clearance (e.g., for utility components).
  • the boring head 100 can be removed from the drill string 20, at or near the exit point, and replaced with another boring head or other drill string 20 attachment before the pull-back operation.
  • the initial ground conditions include generally compressible soils.
  • the ground conditions As the boring operation progresses, it is not unusual for the ground conditions to change to include more difficult conditions, including rock or hard compacted soils.
  • the boring head 100 of the present disclosure provides advantages in having an ability to bore through a variety of soil conditions.
  • the boring head 100 includes a housing assembly 104 (see Figures 2 and 11), a driveline assembly 108, and the one-way clutch 115.
  • the housing assembly 104 of the boring head 100 includes the steering housing 30, a proximal housing 110, and a distal housing 130.
  • the steering, proximal, and distal housings 30, 110, 130 are shown as separate structures in the example embodiment of the boring head 100. In other embodiments, two or more of the housings 30, 110, 130 can be combined into a single unitary structure. In still other embodiments, the housings 30, 110, 130 can be further separated into multiple housings. As illustrated at Figures 2 and 8-11, the proximal housing 110 and the steering housing 30 are connected together by a connection means 182 (see Figure 11). Likewise, the steering housing 30 and the distal housing 130 are connected together by a connection means 184.
  • connection means 182 includes internal threads 182i (female gender), included on a distal end of the proximal housing 110, which threadingly connect to external threads 182e (male gender), included on a proximal end of the steering housing 30.
  • connection means 184 includes internal threads 184i, included on a distal end of the steering housing 30, which threadingly connect to external threads 184e, included on a proximal end of the distal housing 130.
  • a proximal end piece 112 is retained on a proximal end of the proximal housing 110 by a connection means 186.
  • the proximal end of the proximal housing 110 includes internal threads 186i that threadingly connect to external threads 186e included on the proximal end piece 112 thereby forming the connection means 186.
  • a distal end of the distal housing 130 is similarly connected to a distal end piece 132 by a connection means 194.
  • connection means 186 between the proximal housing 110 and the proximal end piece 112, the connection means 182 between the proximal housing 110 and the steering housing 30, the connection means 184 between the steering housing 30 and the distal housing 130, and the connection means 194 between the distal housing 130 and the distal end piece 132 can substitute other connection means (e.g., clamps, collets, latches, press fits, and combinations of these and other connection means) for the threaded connections.
  • the gender of the internal and the external threads 182i, 182e, 184i, 184e, 186i, 186e can be swapped at one or more of the connections means 182, 184, 186, 194.
  • the steering housing 30 includes one or more of the aforementioned biasing features 38.
  • the biasing features 38 include an undercut 34 and a bulge 36 positioned at opposite sides of the steering housing 30.
  • the undercut 34 is radially reduced in size, and the bulge 36 is radially increased in size in comparison with adjacent portions of the steering housing 30 and/or the housing assembly 104.
  • the biasing features 38 can be a single biasing feature 38 or multiple biasing features 38.
  • the biasing features 38 can take forms other than the undercut 34 and/or the bulge 36 of the depicted embodiment.
  • the biasing features 38 can include a vane, a shoe, a plow, an undercut, a bulge, etc. and/or combinations of such features.
  • the biasing features 38 can include kick pads or wear pads (not shown) constructed of wear resistant material, and constructed in a manner to permit replacement and/or modification.
  • Frictional loads, bearing loads, and other loads are typically generated between the housing assembly 104 and the bored hole 50 during the drilling/boring operation.
  • loads can include contact pressure, hydrostatic pressure, hydrodynamic pressure, Coulomb friction, adhesion, viscous friction, and other loads that exist between a boring head and a borehole.
  • An average loading between the housing assembly 104 and the bored hole 50 can be defined as the total loading between the housing assembly 104 and the bored hole 50 divided by an area of the housing assembly 104 exposed to the bored hole 50.
  • the biasing features 38 can promote angular deviation of the housing assembly 104 within the bored hole 50 by generating increased and/or decreased loading on various portions of the housing assembly 104 compared with the average loading.
  • the biasing features 38 encourage an angular offset in the bored hole 50 as the drilling/boring operation progresses.
  • the biasing features 38 contact walls of the bored hole 50 in a manner that generates increased and/or decreased contact pressure between the walls of the bored hole 50 and the biasing features 38 in comparison to an average contact pressure of the housing assembly 104.
  • the biasing features 38 can generate increased and/or decreased friction between the bored hole 50 and the biasing features 38 in comparison to an average friction of the housing assembly 104.
  • the biasing features 38 that are extended farther from a centroid of the housing assembly 104 can add leverage to the non-uniform loading.
  • the biasing features 38 extended farther from the centroid can promote angular deviation of the housing assembly 104 within the bored hole 50 by leverage, even under uniform loading between the housing assembly 104 and the bored hole 50.
  • the bulge 36 typically generates increased contact pressure with the walls of the bored hole 50
  • the undercut 34 typically generates decreased or no contact pressure with the walls.
  • the increased contact pressure at the bulge 36 and the decreased contact pressure at the undercut 34 create a steering force.
  • the steering force generally results in the distal end 105 of the boring head 100 being pushed away from the bulge 36 side of the housing assembly 104 and toward the undercut 34 side.
  • the drill bit, mounted at the distal end 105 of the boring head 100 is thereby steered toward the undercut 34 side of the housing assembly 104.
  • Geometry of the biasing features 38 including geometry of the undercut 34 and the bulge 36 can be selected and customized to give a desired steering force characteristic that is proportionate to other forces involved with the drilling/boring operation and environmental conditions. For example, drilling/boring operations in soft soil conditions may benefit from larger and more aggressive biasing features 38 than are desired in hard packed soil conditions. Likewise, drilling/boring operations intending to employ high thrust can choose the geometry of the biasing features 38 distinct from lower thrust applications.
  • the direction of the drilling/boring operation is controlled by positioning the bulge 36 of the steering housing 30 to the side opposite the desired angular direction. For instance, if the desired boring direction is upward, or in the 12:00 direction, the bulge 36 will be positioned downward, or at the 6:00 position.
  • the position is measured by the sonde (not shown) positioned within a sensor pocket 37 of the steering housing 30 (see Figures 9 and 11). Exemplary illustrations of the sonde are disclosed in U.S. Patent 5,155,442 to Mercer and U.S. Patent 5,880,680 to Wisehart et al., both incorporated herein by reference in their entirety.
  • a rotational position of the sonde is typically calibrated with the orientation of the bulge 36 of the steering housing 30.
  • One such calibration option includes the steps of assembling the components prior to final installation of the sonde, and orienting the sonde in relation to the bulge 36 such that the sonde will read a clock position directly opposite a clock position of the bulge 36.
  • the clock position is an indication of the direction that the boring will progress.
  • Many other options could be performed to aid the accuracy of this step, including the process disclosed in U.S. Patent 6,708,782 to Turney, which is also incorporated herein by reference in its entirety.
  • the driveline assembly 108 of the boring head 100 includes the input drive shaft 142 and an output drive shaft 122 and further includes an internal passage 198 (see Figure 11).
  • a proximal end of the input drive shaft 142 includes connection threads 188e adapted to connect the input drive shaft 142 to the drill string 20.
  • a distal end of the input drive shaft 142 includes internal splines 212 (see Figure 10) adapted to rotationally connect the input drive shaft 142 with the output drive shaft 122.
  • a proximal end of the output drive shaft 122 includes external splines 214 adapted to engage the internal splines 212 of the input drive shaft 142.
  • the internal and external splines 212, 214 can longitudinally slide relative to each other while rotationally coupled.
  • a distal end of the output drive shaft 122 includes connection threads 19Oi adapted to connect the output drive shaft 122 to the drill bit.
  • the drill bit can be selected from a variety of drill bits including drill bits 137, 140, 147 illustrated at Figures 19-21.
  • connection threads 188e, 19Oi illustrate an example of connection means that may further include other connection methods (e.g., clamping collars, collets, cross-pins, etc.) that can combine with or replace the connection threads 188e, 19Oi.
  • the gender of the threads 188e, 19Oi can be swapped at either or both locations.
  • the threads 188e, 19Oi can be right handed or left handed at either or both locations.
  • a bearing 125d (e.g., a thrust bearing) is preferably mounted on the distal end of the input drive shaft 142 and retained thereon by a bearing keeper 192 (see Figures 8 and 9).
  • the bearing 125d is preferably mounted within the proximal housing 110 and retained therein by the proximal end piece 112 (see Figure 12).
  • the input drive shaft 142 is thus rotatably mounted within the proximal housing 110.
  • a bearing 125b (e.g., a thrust bearing) is preferably mounted toward the distal end of the output drive shaft 122 and retained thereon by a bearing keeper 196 (see Figure 14).
  • the bearing 125b is preferably mounted within the distal housing 130 and retained therein by the distal end piece 132.
  • the output drive shaft 122 is thus rotatably mounted within the distal housing 130.
  • the bearing 125b is positioned as close as practical to the connection threads 19Oi or other connection means for the drill bit 137, 140, 147.
  • a longitudinal load path consecutively including the input drive shaft 142 of the driveline assembly 108, the bearing 125d, the proximal housing 110, the steering housing 30, the distal housing 130, the bearing 125b, and the output drive shaft 122 of the driveline assembly 108 is thereby provided to transmit longitudinal loads (e.g., thrust and pull-back loads) and various bending loads between the drill string 20, the boring head 100, and the drill bit 137, 140, 147 (see Figure 11).
  • longitudinal loads e.g., thrust and pull-back loads
  • the one-way clutch 115 is mounted and retained within the proximal housing 110 and includes internal splines 117 (see Figures 9 and 12).
  • the one-way clutch 115 is a well-known mechanical device that includes components that permit transfer of rotational torque between first and second rotational elements in one relative rotational direction while allowing free rotation between the first and the second rotational elements in an opposite relative rotational direction.
  • Exemplary one-way clutches are disclosed in U.S. Patent 4,236,619 to Kuroda, U.S. Patent 4,546,864 to Hagen et. al, and U.S. Patent RE38,498 to Ruth, et. al.
  • a preferred commercially available unit is currently produced by Ringspann GmbH of Bad Homburg, Germany, and is marketed as a Freewheel Element.
  • the first rotational element of the one-way clutch 115 is rotationally connected with the proximal housing 110 and the second rotational element of the one-way clutch 115 is rotationally joined with the internal splines 117.
  • the internal splines 117 of the one-way clutch 115 are adapted to rotationally connect with the external splines 214 of the output drive shaft 122.
  • the second rotational element of the one-way clutch 115 is thus rotationally connected with the driveline assembly 108 of the boring head 100.
  • the one-way clutch 115 is idealized in the preceding paragraph as a device that transfers rotational torque between the first and the second rotational elements in the one relative rotational direction and allows free rotation in the opposite relative rotational direction. It is recognized that certain one-way clutches include characteristics that are not ideal. For example, certain one-way clutches can have slippage, may not engage at slow speeds, can have lag, and can exhibit other non-ideal behavior. Nonetheless, the one-way clutch 115 can include both ideal and non-ideal one-way clutches.
  • the one-way clutch 115 can be replaced (i.e., substituted) by one or more components that allow substantial torque transfer between the driveline assembly 108 and the housing assembly 104 of the boring head 100 during drilling in the straight mode and allow significantly less or no torque transfer between the driveline assembly 108 and the housing assembly 104 during drilling in the deviated mode.
  • certain viscous couplings like a one-way clutch, can transfer substantial torque in a first relative rotational direction and transfer significantly less torque in an opposite second relative rotational direction.
  • the viscous coupling may continuously slip when operated in the first relative rotational direction.
  • the boring head 100 can function in the straight mode, as hereinbefore described, if the housing assembly 104 rotates in the bored hole 50 while the drilling operation is in progress. In such embodiments, the housing assembly 104 can rotate significantly slower than the driveline assembly 108.
  • the boring head 100, with the substituted viscous coupling can also function in the deviated mode, as hereinbefore described, if the housing assembly 104 remains substantially rotationally coupled to the bored hole 50 while the drilling operation is in progress.
  • a clutch that engages and disengages by actuation can replace (i.e., substitute for) the one-way clutch 115 of the boring head 100.
  • actuated clutches typically rotationally couple two components together when actuated and allow free rotation between the two components when not actuated.
  • Other such clutches can allow free rotation between the two components when actuated and rotationally couple the two components together when not actuated.
  • the boring head 100 can also function in the straight mode, as hereinbefore described, if the housing assembly 104 is rotationally coupled to the driveline assembly 108 by the actuated clutch.
  • the boring head 100, with the substituted actuated clutch can also function in the deviated mode, as hereinbefore described, if the housing assembly 104 is rotationally uncoupled from the driveline assembly 108 by the actuated clutch.
  • the boring head 100, with the substituted actuated clutch can be driven in the same direction by the drill string 20 in both the straight and the deviated modes.
  • the straight and the deviated modes can be selected by actuating and releasing the actuated clutch.
  • Such a boring head 100 with the substituted actuated clutch, can therefore rotate the drill bit in the same direction in both the straight and the deviated modes.
  • a drill bit intended to drill in only one rotational direction can be used.
  • the potential for unthreading the threaded connections can be eliminated by substituting the actuated clutch for the one-way clutch 115 and only rotating the drill string 20 in a rotational direction that tightens the threaded connections.
  • Actuating and releasing the actuated clutch can be done by numerous methods. For example, an electrical signal can be transferred from the drilling rig 10 to the electrically actuated clutch via electrical wires routed through the internal passage 198 of the driveline assembly 108. Wireless signals can be relayed by electromagnetic radiation to actuate and release the actuated clutch.
  • Rotational speed of the drill string 20 can actuate the centrifugally actuated clutch upon exceeding a given rotational velocity. Thrusting force of the drill string 20 can actuate the mechanically actuated clutch upon exceeding a given thrust
  • other devices can replace (i.e., substitute for) the one-way clutch 115 of the boring head 100.
  • a hydraulic pump driven by relative motion across the housing assembly 104 and the driveline assembly 108 can selectively rotationally couple and uncouple the housing assembly 104 and the driveline assembly 108.
  • a valve can close a circuit of the hydraulic pump and thereby hydrostatically lock the hydraulic pump and couple the housing assembly 104 and the driveline assembly 108. The valve can also open the circuit of the hydraulic pump and uncouple the housing assembly 104 and the driveline assembly 108.
  • the one-way clutch 115 can be equivalently mounted and connected in other configurations.
  • the first rotational element of the one-way clutch 115 can be rotationally connected with the steering housing 30 or the distal housing 130
  • the second rotational element of the one-way clutch 115 can be rotationally connected with the drill string 20, the output drive shaft 122, and/or the drill bit 137, 140, 147.
  • Other rotational connection means can be substituted for or used in conjunction with the spline 117 of the one-way clutch 115 and the spline 214 of the output drive shaft 122.
  • the example boring head 100 is arranged into convenient subassemblies including a proximal subassembly 140, a central subassembly 160, and a distal subassembly 120.
  • the subassemblies 120, 140, 160 can be preassembled and later assembled as a unit in a final assembly process.
  • the distal subassembly 120 includes the output drive shaft 122, the distal housing 130, the bearing 125b, the bearing keeper 196, and the distal end piece 132.
  • the proximal subassembly 140 includes the input drive shaft 142, the proximal end piece 112, the bearing 125d, the bearing keeper 192, the proximal housing 110, and the one-way clutch 115.
  • the central subassembly 160 includes the steering housing 30, the sonde (not shown), and various mounting hardware for the sonde.
  • a second example embodiment of a boring head 100' is illustrated at Figures 22-42.
  • the boring head 100' extends from a proximal end 103' to a distal end 105' and includes a housing assembly 104' (see Figures 22 and 31), a driveline assembly 108', and the one-way clutch 115.
  • the boring head 100' shares several components, including the one-way clutch 115 (or suitable replacement/substitution), the proximal end piece 112, the bearings 125d and 125b, the bearing keepers 192 and 196, the proximal housing 110, the distal housing 130, and the distal end piece 132 with the boring head 100.
  • the housing assembly 104' resembling the housing assembly 104, includes biasing features 38 on a steering housing 30'.
  • the boring heads 100 and 100' can also be used in similar ways to drill the bored hole 50 in the earth as described above.
  • the boring head 100' is preferably connected at the proximal end 103' to the drill string 20 of the drilling machine 10 and mounts the drill bit at the distal end 105'.
  • the boring head 100' includes means for drilling the straight and the curved segments of the bored hole 50.
  • the straight segments of the bore hole 50 can be produced by continuously rotating the drill string 20 in the first rotational direction causing the one-way clutch 115 to rotationally engage and continuously rotate the steering housing 30' of the housing assembly 104'.
  • the curved segments of the bore hole 50 can be produced by rotating the drill string 20 in the second rotational direction, causing the one-way clutch 115 to disengage the steering housing 30'.
  • the actuating clutch described above in several variations, can also be substituted for the one-way clutch 115 in the boring head 100'. As with the boring head 100, the actuated clutch allows both the curved and the straight segments of the bored hole 50 to be produced by rotating the drill string 20 in the same direction.
  • an input drive shaft 142' and an output drive shaft 122' of the driveline assembly 108' are angularly offset from each other (see Figure 23).
  • the input drive shaft 142 and the output drive shaft 122 of the driveline assembly 108 are co-axial with each other (see Figure 3).
  • an angle a (see Figure 23), defined between rotational centerlines of the input drive shaft 142' and the output drive shaft 122', ranges from between 2.0 degrees and 2.4 degrees. In other embodiments, the angle a ranges between 1.2 degrees and 3.2 degrees. In still other embodiments, the angle a ranges between 0.2 degrees and 4.2 degrees. In yet other embodiments, the angle a ranges between 0 degrees and 90 degrees.
  • the driveline assembly 108' includes a universal joint assembly 170 (see Figures 39-42) rotationally connecting the input drive shaft 142' and the output drive shaft 122'.
  • splines 213 at a distal end of the input drive shaft 142' rotationally couple with proximal splines 176p of the universal joint assembly 170
  • splines 214' at a proximal end of the output drive shaft 122' rotationally couple with distal splines 176d of the universal joint assembly 170.
  • the splines 213, 176p preferably allow translational movement between the input drive shaft 142' and the universal joint assembly 170 along an axis of rotation of the input drive shaft 142'.
  • the splines 214', 176d preferably allow translational movement between the output drive shaft 122' and the universal joint assembly 170 along an axis of rotation of the output drive shaft 122'. The translational movement allowed between the input drive shaft
  • a longitudinal load path consecutively including the input drive shaft 142', the bearing 125d, the proximal housing 110, the steering housing 30', the distal housing 130, the bearing 125b, and the output drive shaft 122' is provided to transmit longitudinal loads (e.g., thrust and pull-back loads) and various bending loads between the drill string 20, the boring head 100', and the drill bit 137, 140, 147 (see Figure 31).
  • the universal joint 170 includes a proximal yoke 172p, a spider 174, and a distal yolk 172d.
  • the proximal yolk 172p includes the splines 176p, concentric about an outer cylinder 180p, and is pivotally connected with the spider 174 by a pair of connection pins (not shown).
  • the distal yolk 172d includes the splines 176d, concentric about an outer cylinder 180d, and is pivotally connected with the spider 174 by another pair of connection pins (not shown).
  • the proximal and distal yolks 172p, 172d can be interchangeable with each other. In other embodiments, other devices can replace the universal joint 170.
  • a flexible driveline can transfer rotational motion across the angular offset of the angle a and thereby directly or indirectly connect the drill string 20 to the drill bit 137, 140, 147 and also rotationally connect with the one-way clutch 115.
  • Other examples of universal joint replacements include flexible couplings and bevel gears.
  • the driveline assembly 108' includes an internal passage 198', similar to the internal passage 198 of the driveline assembly 108.
  • the internal passage 198' extends from the proximal end 103' to the distal end 105' of the boring head 100' and thereby allows fluid, electrical wiring, etc. to pass through the drill string 20 to the drill bit 137, 140, 147.
  • the internal passage 198' extends through the input drive shaft 142', the universal joint 170, and the output drive shaft 122'.
  • the example boring head 100' is arranged into convenient subassemblies including a proximal subassembly 140', a central subassembly 160', and a distal subassembly 120'.
  • the subassemblies 120', 140', 160' can be preassembled and later assembled as a unit in a final assembly process.
  • the distal subassembly 120' includes the output drive shaft 122', the distal housing 130, the bearing 125b, the bearing keeper 196, and the distal end piece 132.
  • the proximal subassembly 140 includes the input drive shaft 142', the proximal end piece 112, the bearing 125d, the bearing keeper 192, the proximal housing 110, and the one-way clutch 115.
  • the central subassembly 160 includes the steering housing 30', the sonde (not shown), various mounting hardware for the sonde, and the universal joint 170.
  • the steering housing 30' accommodates the angular offset of the angle a and holds the proximal and the distal subassemblies 140', 120' such that the angle ⁇ is formed between the rotational centerlines of the input drive shaft 142' and the output drive shaft 122'.
  • the steering housing 30' can include a proximal bore 178p and a distal bore 178d.
  • the proximal bore 178p can rotatably support the outer cylinder 180p
  • the distal bore 178d can rotatably support the outer cylinder 180d of the universal joint 170.
  • the biasing features 38 on the steering housing 30' include an undercut 34' and a bulge 36' that function in and interact with the bore hole 50 similar to the undercut 34 and the bulge 36 of the steering housing 30 as described above.
  • a sensor pocket 37' suitable to hold the sonde and/or other navigational instrumentation, can be positioned within the bulge 36'.
  • the present disclosure further includes a third example embodiment and a fourth example embodiment of boring heads.
  • the third example embodiment includes parallelly offset input and output drive shafts.
  • the one-way clutch 115 (or suitable replacement/substitution) selectively engages and disengages a steering housing of the third example embodiment. Straight segments of the bored hole 50 are produced when the oneway clutch 115 engages the steering housing, and curved segments of the bored hole 50 are produced when the one-way clutch 115 disengages the steering housing.
  • the form of the third example embodiment is similar to the form shown at Fig. 7 of U.S. Patent Application No. 11/134,239, previously incorporated by reference.
  • Various means for rotationally coupling parallelly offset input and output drive shafts are known in the art. For example, two of the universal joints 170 can be included in a driveline assembly and thereby couple the parallelly offset input and output drive shafts.
  • the fourth example embodiment of the boring head includes skewed input and output drive shafts that are neither parallel nor intersecting.
  • the one-way clutch 115 (or suitable replacement/substitution) selectively engages and disengages a steering housing of the fourth example embodiment of the boring head.
  • Straight segments of the bored hole 50 are produced when the one-way clutch 115 engages the steering housing, and curved segments of the bored hole 50 are produced when the one-way clutch 115 disengages the steering housing.
  • Various means for rotationally coupling skewed input and output drive shafts are known. in the art.
  • two of the universal joints 170 can be included in a driveline assembly and thereby couple the skewed input and output drive shafts.
  • a potential to unscrew threaded connections is inherent. Rotation of the drill string 20 in an unscrewing direction may continue over a significant period of time if that is required by the drilling/boring operation. The threaded connections may thus unscrew and become disconnected resulting in losing components of the drill string 20 and/or the boring head 100, 100' in the earth.
  • a first method to reduce the potential for unscrewing the threaded connections of the drill string 20, the boring head 100, 100', and the drill bit 137, 140, 147 involves monitoring and controlling the drilling torque applied by the drilling rig 10.
  • the drilling torque applied to the drill string 20 in the unscrewing direction can be regulated and/or limited so as never to exceed an unscrewing torque limit.
  • the drilling torque applied in a screwing direction can be monitored along with a maximum screwing torque experienced by each threaded connection of the drill string 20, the boring head 100, 100', and the drill bit 137, 140, 147.
  • the maximum screwing torques experienced by each threaded connection in a given configuration are compared and a lowest of the maximum screwing torques can be used to calculate an unscrewing torque limit. For example, a screwing torque of 1,000 N-m was experienced by a third joint of the drill string 20, and all other threaded joints of the drill string 20 and the boring head 100 have experienced higher screwing torques.
  • a second method to reduce and/or eliminate the potential for unscrewing the threaded connections of the drill string 20, the boring head 100, 100', and the drill bit 137, 140, 147 involves locking the threaded connections.
  • Figures 43-46 illustrate an example method of locking the threaded connections using a threaded connection between a steering housing 30" and a proximal housing 110' as an example locking system 230.
  • the steering housing 30" includes a threaded hole 238 and a sliding surface 246 near external threads 182e".
  • the proximal housing 110' includes pin holes 236 near internal threads 182i'.
  • a sliding surface 244 of a locking collar 232 is installed over the external threads 182e" and onto the sliding surface 246 before the internal and external threads 182i', 182e" are threadingly connected.
  • the internal and external threads 182i', 182e” are then threadingly connected and properly tightened (see Figures 44 and 45).
  • Locking pins 234, included on the locking collar 232 are aligned with the pin holes 236 of the proximal housing 110'.
  • the locking collar 232 is then slid toward the proximal housing 110' thus engaging the locking pins 234 in the pin holes 236.
  • a shoulder bolt 240 is then inserted through a retention hole 242 on the locking collar 232 and into the threaded hole 238 on the steering housing 30".
  • a third method to reduce and/or eliminate the potential for unscrewing the threaded connections of the drill string 20, the boring head 100, 100', and the drill bit 137, 140, 147 involves replacing some or all of the threaded connections and the threaded features 182, 182', 184, 184' 188e, 188e', 19Oi, 19Oi' with non-threaded connections and/or features. Examples of such connections and features known in the art include clamping collars, clamps, collets, cross-pins, latches, press fits, and combinations of these elements.
  • a fourth method to reduce the potential for unscrewing the threaded connections of the drill string 20 and the boring head 100, 100' involves monitoring a rotational position of the boring head 100, 100' and a rotational position of the drill string 20 at its attachment to the drilling rig 10. By comparing these rotational positions, the unscrewing of the threaded connections can be detected if the rotational position of the drill string 20 adjacent the drilling rig 10 continues to change but the rotational position of the boring head 100, 100' does not change or changes at a slower rate. Upon detecting potential unscrewing, the rotation of the drill string 20 can be stopped before a threaded connection has been completely unthreaded and disconnected.
  • a preferred method for implementing the fourth method is to select the first rotational direction as the unscrewing direction and to select the one-way clutch 115 as a one-way clutch with minimal slippage characteristics. Since the steering housing 30, 30' rotates with the boring head 100, 100' in the straight mode, the sonde can be used to monitor the rotational position of the boring head 100, 100' in the straight mode. Another rotational position sensor monitors the rotational position of the drill string 20 adjacent the drilling rig 10.
  • unthreading of the threaded connections in the straight mode can be detected by comparing the rotational position of the boring head, as measure by the sonde, and the rotational position of the drill string 20 adjacent the drill rig 10, as measured by the other rotational position sensor. If a relative rotational position between the boring head 100, 100' and the drill string 20 adjacent the drilling rig 10 is non-zero, potential unscrewing has been detected. Upon the relative rotational position reaching a certain threshold value, the rotation of the drill string 20 in the first rotational direction can be suspended, thereby preventing the unthreading and disconnection of a threaded connection.
  • the preferred method of the preceding paragraph does not measure the relative rotational position between the boring head 100, 100' and the drill string 20 adjacent the drilling rig 10 when the drill string 20 is rotated in the second rotational direction and the boring head 100, 100' is operated in the deviated mode.
  • the steering housing 30, 30' of the boring head 100, 100' does not rotate substantially in the bored hole 50 and thus the sonde does not rotate substantially.
  • the second rotational direction is the screwing direction, there is no unscrewing potential for the threaded connections in the deviated mode.
  • the preferred method of the preceding two paragraphs can be refined to account for torsional windup of the drill string 20.
  • a length L of the deployed drill string 20 increases, and an angular deflection (i.e., rotational or angular deformation along the length L of the drill string 20) can become significant.
  • an angular deflection i.e., rotational or angular deformation along the length L of the drill string 20
  • the angular deflection, or wind-up increases.
  • the angular deflection is detected as a non-zero relative rotational position between the boring head 100, 100' and the drill string 20 adjacent the drilling rig 10.
  • a non-zero relative rotational position also indicates potential unscrewing of a threaded connection.
  • T the torque applied by the drilling rig 10 to the drill string 20
  • L the currently deployed length of the drill string 20
  • G modulus of rigidity, a property of the material of the drill string 20.
  • J polar area moment of inertia, a property of a cross- sectional shape of the drill string 20.
  • Other mathematical models can also be used, particularly if friction between the bored hole 50 and the drill string 20 is significant over the length L.
  • the above mathematical model generally bounds a maximum angular deflection ⁇ for the drill string 20 regardless of environmental boundary conditions (e.g., the friction along the length L of the drill string 20).
  • the length L of the drill string 20 is determined from a separate control system or controller that provides a signal corresponding to drill string 20 length L.
  • One example of such a system is described in co-assigned U.S. Patent 6,308,787 to Alft, incorporated herein by reference in its entirely.
  • the signal can be provided by a manual input from the operator.
  • the torque T applied by the drilling rig 10 to rotate the drill string 20 must also be determined.
  • the torque T can be measured during rotation of the drill string 20.
  • An alternative method would be to measure hydraulic pressure provided to hydraulic motors, which will be proportional to the torque T.
  • a pressure transducer can provide an input signal corresponding to the hydraulic pressure required to rotate a drive shaft or an output shaft. Combining these two factors, T and L, allows the controller to estimate the drill string 20 wind- up.
  • the threshold value indicating unscrewing of the threaded connections can be adjusted by adding the angular deflection ⁇ .
  • the first, second, third, and fourth unscrewing prevention methods can be used in conjunction with each other and in conjunction with other unscrewing prevention methods.
  • An example method for selectively using continuous forward and reverse rotation for directional boring includes steps illustrated by a flowchart at Figure 47.
  • the flowchart begins at a start position 302.
  • a first step 304 upon starting includes defining the desired path 60 of the bored hole 50.
  • the desired path 60 typically considers and avoids obstacles in the vicinity of the bored hole 50 and selects the entry point 52 and, if desired, the exit point.
  • the desired path 60 can also consider drainage slope and other desired characteristics of the bored hole 50.
  • a second step 306 positions the drilling rig 10 near the entry point 52 and attaches the boring head 100, 100' to the drill string 20 of the drilling rig 10.
  • a third step 308 initiates drilling of the bored hole 50. The drilling is typically initiated at the entry point 52 along the desired path 60.
  • a fourth step 310 gathers navigational data (e.g., from the sonde) and projects/estimates a trajectory of the bored hole 50 from imminent drilling in a current mode (i.e., straight or deviated) and, if in the deviated mode, a current directional orientation of the steering housing 30. The trajectory is compared with the desired path 60 of the bored hole 50. Other possible trajectories from the other mode and/or other directional orientations of the steering housing 30 can also be compared with the desired path 60 of the bored hole 50 in the fourth step 310.
  • a fifth step 312 evaluates whether the straight mode or the deviated mode would best match impending bored hole 50 with the desired path 60.
  • a sixth step 314 is executed. If the fifth step 312 chooses the straight mode, then an eighth step 318 is executed.
  • the sixth step 314 selects a desired directional orientation for drilling in the deviated mode and sets the orientation of the steering housing 30 to the desired directional orientation by rotating the drill string 20 in the first rotational direction.
  • a seventh step 316 resumes drilling by thrusting and rotating the drill string 20 in the second rotational direction.
  • a ninth step 320 evaluates a current position of the boring head 100, 100' .
  • the eighth step 318 resumes drilling by thrusting and rotating the drill string 20 in the first rotational direction.
  • a tenth step 322 evaluates if the exit point has been reached and/or if the drilling is otherwise complete. If the tenth step 322 results in "yes”, then an end position 324 of the flowchart is reached. If the tenth step 322 results in "no", then the fourth step 310 is re-executed.
  • the flow chart of Figure 47 begins at the start position 302 and flows from the first step 304 to the second step 306 to the third step 308 to the fourth step 310 to the fifth step 312, which is a branching step.
  • the branch of the flow chart beginning at the sixth step 314 continues to the seventh step 316 then to the ninth step 320 then to the tenth step 322, which is a branching step.
  • the branch of the flow chart beginning at the eighth step 318 continues to the ninth step 320 then to the tenth step 322, which is a branching step.
  • the clock position signal, monitoring the position and the orientation of the steering housing 30, 30' could be generated using one of a number of systems; for example, from raw data generated by the sonde or transmitter located in the steering housing 30, 30' of the drill head 100, 100'.
  • the sonde includes an electronic device that measures the clock position or rotational orientation, and generates raw clock position data.
  • the sonde further includes data processing capability to manipulate the raw clock position data to generate data in a number of different configurations.
  • a first, common configuration of data is generated by an arrangement including a wireless communication link 782 and the receiver 780 located above ground.
  • the sonde converts the raw clock position data into a digital signal superimposed on an electromagnetic signal that is transmitted to the above ground receiver 780.
  • the above ground receiver then transmits an associated signal to a remote unit mounted on the drilling rig 10.
  • the associated signal includes filtered clock position data.
  • the filtered clock position data is a representation of the raw clock position data.
  • the data manipulation at the sonde, necessary to transmit the signal using the wireless transmission link 782, is effectively a type of filter.
  • the wireless communication link 782 is replaced with a wireline, wherein there is a physical communication link passing through the drill string 20 between the sonde and the remote unit located on the drilling rig 10.
  • This configuration will allow transmission of a different signal; the raw clock position data will not need to be filtered to the same level as with the wireless communication of the first configuration, because the wireline has capacity to transmit data at a higher rate of transmission, thus requiring less filtering.
  • the remote unit is capable of generating the clock position signal that is an indication of the measured position of the drill head 100, 100'.
  • the signal is transmitted at a frequency, which the wireless communication link 782 is capable of supporting.
  • Figures 19-21 illustrate various configurations of drill bits that are useful with the presently disclosed boring head embodiments 100, 100'.
  • Figure 19 illustrates an embodiment of a drag cutting bit 140 configured to mount to the connection threads 19Oi, 19Oi' of the output drive shaft 122, 122'.
  • Figure 20 illustrates a roller cone bit 137
  • Figure 21 illustrates another embodiment of a drag cutting bit 147 configured to mount to the connection threads 19Oi, 19Oi' of the output drive shaft 122, 122'.
  • One aspect of the present disclosure is the simplicity of varying operation between the two drilling modes, i.e., the straight drilling mode and the deviated drilling mode.
  • the only required difference between the two modes is the rotational direction of the drill string 20.
  • thrust from the drill string 20 is applied to the drill bit to cause the bored hole 50 to advance.
  • the thrust can be held constant.
  • the drilling rig 10 typically includes a diesel motor that powers a hydraulic pump, and an operator station with controls that allow the operator to control the hydraulic system, the flow rate and flow direction of oil transferred to rotation motors.
  • the rotation motors cause the drill string 20 to rotate and force the drill string to extend, during boring, or retract, during backreaming.
  • the longitudinal movement of the drill string 20 is typically accomplished by attaching the drill string 20 to a gearbox.
  • the gearbox is supported for linear movement along a rack.
  • the linear movement is typically provided by a hydraulic cylinder or by a hydraulic motor, pinion gear and rack gear. These mechanisms are not illustrated as they are well known and any configuration can be used.
  • the rotation of the gearbox is typically provided by a hydraulic motor that is mounted to the gearbox.
  • the embodiments of the present disclosure may be used in applications other than horizontal boring. For example, in many vertical drilling applications, directional drilling techniques are used. The details disclosed in the above teachings are recognized to be applicable to such vertical drilling applications. In addition, many other modifications and variations of the present invention are possible in light of the above teachings. It is therefore to be understood that, within the scope of the appended claims, the invention may be practiced otherwise than as specifically described.

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  • Life Sciences & Earth Sciences (AREA)
  • Engineering & Computer Science (AREA)
  • Geology (AREA)
  • Mining & Mineral Resources (AREA)
  • Physics & Mathematics (AREA)
  • Environmental & Geological Engineering (AREA)
  • Fluid Mechanics (AREA)
  • General Life Sciences & Earth Sciences (AREA)
  • Geochemistry & Mineralogy (AREA)
  • Earth Drilling (AREA)

Abstract

L'invention concerne un système de forage comprenant une tête de forage et conçu pour se coupler à un train de tiges de forage d'une machine à forer afin de forer un trou de sonde. La tête de forage comprend un système de roue libre, un boîtier de direction et un trépan. Le boîtier de direction comprend des entités de sollicitation qui favorisent une direction de forage déviée par rapport à l'axe adjacent du train de tiges de forage. Lorsqu'on fait tourner le train de tiges de forage dans un premier sens, le système de roue libre s'enclenche et fait tourner le boîtier de direction avec le train de tiges de forage, faisant ainsi tourner en continu les entités de sollicitation. La déviation de la direction de forage est donc modifiée en continu, empêchant un cumul significatif de la déviation et produisant un segment sensiblement rectiligne du trou de sonde. Lorsqu'on fait tourner le train de tiges de forage dans un deuxième sens, le système de roue libre débraie et maintient par frottement le boîtier de direction, l'empêchant de tourner dans le trou de sonde. Les entités de sollicitation du boîtier de direction sont ainsi immobilisées en rotation par rapport au trou de sonde et les déviations de la direction de forage se cumulent, produisant un segment incurvé du trou de sonde.
PCT/US2010/026524 2009-03-16 2010-03-08 Système et procédé de forage dirigé comprenant une rotation inverse continue WO2010107606A2 (fr)

Applications Claiming Priority (2)

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US61/160,552 2009-03-16

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Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP2994594A4 (fr) * 2013-05-09 2017-04-19 Halliburton Energy Services, Inc. Outil de pilotage à manchon excentrique et son procédé d'utilisation
WO2023043977A1 (fr) * 2021-09-16 2023-03-23 Vermeer Manufacturing Company Trépan directionnel horizontal à mode roue libre

Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US20050274548A1 (en) * 2004-05-21 2005-12-15 Vermeer Manufacturing System for directional boring including a drilling head with overrunning clutch and method of boring
US7360609B1 (en) * 2005-05-05 2008-04-22 Falgout Sr Thomas E Directional drilling apparatus
US7481282B2 (en) * 2005-05-13 2009-01-27 Weatherford/Lamb, Inc. Flow operated orienter

Patent Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US20050274548A1 (en) * 2004-05-21 2005-12-15 Vermeer Manufacturing System for directional boring including a drilling head with overrunning clutch and method of boring
US7360609B1 (en) * 2005-05-05 2008-04-22 Falgout Sr Thomas E Directional drilling apparatus
US7481282B2 (en) * 2005-05-13 2009-01-27 Weatherford/Lamb, Inc. Flow operated orienter

Cited By (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP2994594A4 (fr) * 2013-05-09 2017-04-19 Halliburton Energy Services, Inc. Outil de pilotage à manchon excentrique et son procédé d'utilisation
US10000971B2 (en) 2013-05-09 2018-06-19 Halliburton Energy Services, Inc. Steering tool with eccentric sleeve and method of use
WO2023043977A1 (fr) * 2021-09-16 2023-03-23 Vermeer Manufacturing Company Trépan directionnel horizontal à mode roue libre
US11946372B2 (en) 2021-09-16 2024-04-02 Vermeer Manufacturing Company Horizontal directional drill with freewheel mode

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