BIT BREAKER

A bit breaker for loosening or tightening a drill bit on a drill string incorporating a mud motor permits rotation of the drill bit while the bit box is held stationary. The bit breaker has a lower body which is held stationary on the rig floor and an upper body which houses the drill bit and which is connected to the lower body through a rotational connection. An actuator connected between the upper and lower bodies causes the upper body to rotate relative to lower body for co-rotating the drill bit. The bit box of the mud motor is held stationary using the lower tong of a conventional make-and-break unit.

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Description
FIELD OF THE INVENTION

Embodiments of the invention are related to apparatus used during threaded connection and disconnection of drill bits to a tubular drill string and, more particularly, for use where a mud motor is incorporated into the drill string.

BACKGROUND OF THE INVENTION

In the oil and gas industry, drill bits are connected to a downhole end of a string of tubulars for drilling a wellbore. The drill bit is threaded to a bottom of the downhole-most drill string tubular or to a bottomhole assembly connected thereto.

Conventional wrenches or tongs cannot be used directly to tighten or loosen bits from the drill string tubular or bottomhole assembly. It is known to provide a shaped box called a bit breaker. The bit breaker is fit to the rig floor, such as to the rotary table. The bit breaker is configurable to the bit shape so as to engage and control bit rotation without damage to the bit. The bit breaker holds the bit stationary while the drill string is rotated for tightening or loosening the bit thereto.

In other implementations, mud motors are incorporated into drill string tubulars or a bottomhole assembly to drive and steer the drill bit. While mud motors are known to be used to enhance rate of penetration (ROP) when drilling vertical wellbores, they are more typically incorporated into bottomhole assemblies for directional drilling of deviated wellbores. Mud motors use mud flow to generate bit rotational speed and torque. Mud is pumped down the drill string to a power section of the mud motor. The power section consists of a lobed steel rotor inside a lobed stator made from a special resilient compound. The rotor, which is usually chromed or polished, has one less lobe than the stator so the mud forces the rotor to rotate within the stator. The rotation of the rotor is transmitted to a drive shaft and transmission section which drives a rotatable bit box on the motor's distal end to hold the drill bit.

In the case where a mud motor is used, the bit box of the mud motor rotates independent from the drill string. Thus, make-up and break-out of a drill string incorporating the mud motor, using a conventional bit breaker with rotation of the drill string, will not result in rotation of the mud motor's bit box and therefore will not act to tighten or loosen the bit thereto.

The oil and gas industry has made a great effort to eliminate the use of manual power tongs wherever possible as they are very dangerous to rig personnel. Further, the process using manual tongs becomes very time consuming to make-up and break-out drill string connections and valuable drilling time is lost.

In order to increase safety and efficiency, hydraulic make-and-break units which comprise power tongs or wrenches are now used to replace manual methods of making-up and breaking out drill strings. Typically, such units comprise rotatable upper tongs for rotating a new stand of drill pipe and stationary lower tongs for holding the string stationary. In the case where a mud motor is used, when the drill bit is positioned and held stationary in the bit breaker, the rotatable bit box is generally adjacent the lower stationary tongs. The power wrench cannot be lowered sufficiently on the rig floor to permit the upper rotatable tongs to engage the bit box of the mud motor for rotation relative to the stationary bit. Accordingly, Applicant notes that, despite the risks to personnel and the mud motor itself, the industry continues to use a manual rotary tong to rotate the bit box while a conventional bit breaker holds the bit stationary.

In addition to the undesirable use of a manual rotary tong, rotation of the bit box may result in damage to the mud motor. When engaging the bit box one must be sure to avoid contacting the end cap directly above the bit box with the tong dies. Further, it has been recommended that the bit box not be held stationary while rotating the mud motor counter-clockwise, or that the mud motor be held stationary while the bit box is rotated clockwise. Such actions may cause the internal mud motor connections to back off resulting in damage to the mud motor. Although rotating in the opposite counterclockwise direction will result in drilling fluid being pushed out the top end, the internal connections will not be at risk of disconnecting or getting wet and causing damage to the motor.

There is a need for apparatus which permits safe and relatively rapid connection and disconnection of a drill bit from a drill string when the drill string incorporates a mud motor and which does not cause costly damage to the mud motor.

SUMMARY OF THE INVENTION

In embodiments disclosed herein, a conventional hydraulic make-and-break unit can now be employed to make and break a drill bit from the bit box of a mud motor. A bit breaker includes that which permits a drill bit to be bi-directionally and rotationally indexed for loosening and tightening a threaded connection to the mud motor's bit box. The bit box 6 can be held stationary, such as by using lower stationary tongs of the conventional hydraulic make-and-break unit. In one embodiment, the bit breaker 10 has an upper rotatable body for rotating the drill bit relative to a lower stationary body and about an axis common with the bit box. The upper body can be rotationally guided by an arcuate track between the upper and lower bodies. A double-acting hydraulic actuator, between the upper and lower bodies, can provide the bidirectional rotation of the upper body and drill bit. Use of an actuator such as a hydraulic ram provides for a modest rotational range sufficient for making and breaking the threaded connection.

In one broad aspect, a bit breaker for use in threading a drill bit to or from a mud motor having a lower, normally rotatable bit box, the bit breaker comprising: a rotatable bit breaker body for housing the drill bit for co-rotation therewith; and an actuator connected between the bit breaker body and a stationary member, wherein, when the mud motor's bit box is held stationary, the actuator is actuable to co-rotate the bit breaker body and drill bit housed therein relative to the stationary member about an axis common to the drill bit, the bit breaker and the mud motor, the body being rotated in a first direction for loosening a threaded connection between the drill bit and the mud motor's bit box; and in a second direction for tightening the threaded connection between the drill bit and the mud motor's bit box.

In another broad aspect, a system for applying torque to a drill bit on a mud motor with a lower, normally rotatable bit box, the system comprising: a bit breaker having a rotatable bit breaker body for housing the drill bit for co-rotation therewith; and an actuator connected between the bit breaker body and a stationary member, the actuator causing the body to rotate relative to the stationary member; and a tong for holding the bit box stationary, wherein, when the tong is actuated to hold the mud motor's bit box stationary, the actuator is actuable to co-rotate the bit breaker body and drill bit housed therein relative to the stationary member about a common axis, the body being rotated in a first direction for loosening a threaded connection between the drill bit and the mud motor's bit box; and in a second direction for tightening the threaded connection between the drill bit and the mud motor's bit box.

In a broad method aspect, a method for applying torque to a drill bit on a mud motor with a lower, normally rotatable bit box for loosening or tightening a threaded connection between the drill bit and the bit box, comprises: providing a bit breaker having a rotatable bit breaker body having an enclosure for housing the drill bit therein for co-rotation therewith; and an actuator connected between the bit breaker body and a stationary member, the actuator being actuable to cause the body to rotate relative to the stationary member about an axis common to the drill bit and the bit box; inserting the drill bit threaded to the bit box into the enclosure of the bit breaker body; engaging the bit box for holding the bit box stationary; actuating the actuator to co-rotate the bit breaker body and the drill bit housed therein in a first direction for loosening a threaded connection between the drill bit and the mud motor's bit box; or in a second direction for tightening the threaded connection between the drill bit and the mud motor's bit box.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1A is a plan view of a prior art bit breaker;

FIG. 1B is a cross-sectional view of the prior art bit breaker of FIG. 1 having a drill bit engaged therein;

FIG. 2 is a perspective view of a conventional drilling string incorporating a mud motor;

FIG. 3A is a schematic illustration of an embodiment of the invention;

FIG. 3B is a schematic illustration of another embodiment of the invention;

FIG. 4 is a perspective view of an embodiment of the invention according to FIG. 3B, a bit breaker housing a drill bit connected to a bit box of a mud motor incorporated into the drill string;

FIGS. 5A-5C are perspective views of a rotational connection between the upper body and the lower body, the hydraulic actuator having been removed; more particularly

FIG. 5A is a front perspective view showing an arcuate groove formed on an underside of the upper body and an arcuate projection formed on the upper side of the lower body for forming the rotational connection;

FIG. 5B is an upwardly-viewed, front perspective view of the upper body and the arcuate groove according to FIG. 5A; and

FIG. 5C is a front perspective view of the lower body and the arcuate projection according to FIG. 5A;

FIGS. 6A to 6D are plan views illustrating orientation of the upper body relative to the lower body as a result of the actions of an actuator acting upon the upper body, more particularly

FIG. 6A illustrates the upper body aligned with the lower body in a break-out position;

FIG. 6B illustrates the upper body rotated out of alignment with the lower body when the actuator is actuated to rotate the upper body for loosening the drill bit from the bit box;

FIG. 6C illustrates the upper body rotated out of alignment with the lower body in a make-up position; and

FIG. 6D illustrates the upper body rotated into alignment with the lower body when the actuator is actuated to rotate the upper body for tightening the drill bit to the bit box

FIG. 7 is a rear perspective view of an embodiment of the bit breaker according to FIG. 4, the drill string and drill bit being removed therefrom;

FIG. 8 is a front perspective view of a system incorporating the bit breaker of FIG. 3 for connecting or disconnecting a drill bit from a drill string incorporating a mud motor therein, the upper body of the bit breaker being aligned with the lower body of the bit breaker; and

FIG. 9 is a front perspective view according to FIG. 7 wherein the upper body of the bit breaker has been rotated relative to the lower body of the bit breaker.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

As shown in FIGS. 1A and 1B, prior art bit breakers 1 typically comprise a rectangular, box-like body 2 which defines an enclosure 3 therein which is configured to engage a drill bit 4 therein during making-up or breaking-out of a drill string 5. The body 2 of the bit breaker 1 typically engages a floor of a drilling rig, such as in an opening in a rotary table, for holding the body 2 stationary. The drill bit 4 is lowered into the enclosure 3 and is held stationary therein while the drill string 5, threadedly connected to the drill bit 4, is rotated for tightening or loosening the threaded connection therebetween. The drill string 5 is generally rotated using a conventional power wrench, typically part of a conventional hydraulic make-and-break unit on the rig floor.

Having reference to FIG. 2, while embodiments described herein may be useful for making-up or breaking-out a conventional drill string used for vertical drilling, the bit breaker 10 is particularly useful where the drill string 5 incorporates a mud motor M, such as is used for directional drilling. As described above, conventional bit breakers and hydraulic make-and-break tongs do not readily accommodate mud motors M. The mud motor M terminates with a lower, normally rotatable bit box 6 to which the drill bit 4 is threadedly connected. Embodiments are described herein in the context of the drill string 5 incorporating the mud motor M.

As shown in FIGS. 3A, 3B and 4, an embodiment of the bit breaker 10 permits a drill bit 4 to be bi-directionally rotated for loosening or tightening threaded connections between the mud motor's bit box 6 and the drill bit 4, while the bit box 6 is held stationary. The bit box 6 is held stationary using means such as a lower stationary tong 8 of a conventional hydraulic make-and-break unit. The bit breaker 10, and the drill bit 4 housed therein, are caused to co-rotate about a common axis X. An actuator 12 is connected between a bit breaker body 14 and a stationary member, causing the body 14 to rotate relative thereto. In embodiments, the stationary element S may be a permanent stationary element, such as a rig floor F (FIG. 3A) or it may be an intermediate member 54 of the body 14 (FIG. 3B) which is held stationary, such as to the rig floor F. The common axis X is common to the bit breaker 10 and the drill bit 4, as well as the bit box 6 and the drill string 5 thereabove.

Having reference to FIGS. 4-5C, according to an embodiment, the body 14 of the bit breaker 10 comprises a rotatable bit breaker body 14 for housing the drill bit 4 for co-rotation therewith. The body 14 comprises an upper body 16 and a lower body 18. The lower body 18 acts as the intermediate member 54 and is secured to the rig floor F to act as the stationary member S. The lower body 18 can have a depending portion or profile for dropping into and matching a receiving profile in the rig floor F and held stationary for forming the stationary member. The depending and receiving profiles are typically rectangular or square for relative restraining rotation therebetween. Further the depending portion may be pins for engaging in matching receiving profiles in the rig floor F.

The upper body 16 defines an enclosure 20 for housing the drill bit 4 therein. In embodiments, the enclosure 20 is configured to a shape of the drill bit 4. The upper body 16 and the lower body 18 are connected therebetween by a rotational connection 22 (FIG. 5A). The rotational connection 22 co-operates between the upper body 16 and lower body 18 to permit the upper body 16 to rotate bi-directionally relative to the lower body 18 about the common axis X.

The rotational connection 22 may be any suitable rotational connection, such as a pin connection, arcuate track or the like, which permits the upper body 16 to rotate relative to the lower body 18. The actuator 12 is operatively connected to the upper body 16 so as to move the upper body 16 for rotation about the rotational connection 22.

In an embodiment, as shown in FIGS. 5A-5C, the rotational connection 22 comprises an arcuate track comprising arcuate projection 24 which co-operates with an opposing, arcuate groove 25 for engagement and movement therein when the projection 24 and groove 25 are mated. The projection 24 can be formed on either of a lower surface 28 of the upper body 16 or on an upper surface 30 of the lower body 18. The opposing groove 25 is formed on an opposing surface, being the upper surface 30 of the lower body 18 or on the lower surface 28 of the upper body 16, respectively. As will be understood by one of skill in the art, when the projection 24 is mated in the groove 25 and the actuator 12 is actuated to move the upper body 16 relative to the lower body 18, the projection 24 and groove 25 cause rotation of the upper body 16 about the common axis X.

As one of skill will appreciate, the drill bit 4 is not continuously rotated for completely threading onto or for completely unthreading from the bit box 6. The bi-directional rotation of the upper body 16 is a short-arc or indexed rotation, typically about 30-40 degrees in either direction. The indexed rotation is sufficient to tighten the drill bit 4 to the bit box after the drill bit 4 has been manually hand-threaded onto the bit box 6 when making up the string 5. Similarly, when breaking out the drill string 5, the indexed rotation is sufficient to loosen the threaded connection so that the bit 4 can be manually hand-rotated for removal from the bit box 6.

The actuator 12 is any actuator which is actuable to impart movement to the upper body 16 relative to the lower body 18. As one of skill in the art would appreciate, the actuator 12 may be a linear actuator such as an air cylinder or a hydraulic cylinder, a screw actuator or the like or could be a worm gear arrangement or rack and pinion and the like.

In embodiments of the invention, the actuator 12 causes the upper body 16 to move in a first direction to loosen the threaded connection between the drill bit 4 and the bit box 6 when breaking out a drill string 5. Further, the actuator 12 causes the upper body 16 to move in a second direction to tighten the threaded connection between the drill bit 4 and the bit box 6 when making up the drill string 5.

As shown in FIGS. 6A to 6D, for conventionally threaded tubulars, when viewed from above the rig floor F and looking downhole, the first direction is a clockwise rotation (from FIG. 6A to FIG. 6B) of the upper body 16 relative to the lower body 18 for loosening the drill bit 4 from the bit box 6. The second direction is a counter-clockwise rotation (from FIG. 6C to FIG. 6D) of the upper body 16 relative to the lower body 18 in order to tighten the drill bit 4 to the bit box 6. Accordingly, the components of the bit breaker are configured to effect the desired rotation.

In an embodiment, as shown in FIGS. 6A to 6D and 7, wherein the actuator 12 is a double-acting hydraulic cylinder, the action on the upper body 16 is a push/pull action. The hydraulic actuator 12 is mounted to the bit breaker 10 so as to apply a pushing force to the upper body 16 when loosening the threaded connection between the drill bit 4 and the bit box 6. The hydraulic actuator 12 applies a pulling force to the upper body 16 for tightening the threaded connection between the drill bit 4 and the bit box 6. For the double-acting hydraulic cylinder, orienting the hydraulic actuator 12 relative to the bit breaker 10 in this manner provides the greatest “pushing force” for applying torque to the threaded connection between the drill bit 4 and the bit box 6 for loosening the threaded connection. This is particularly advantageous as the operation of the drill bit on the threaded connection is likely to have resulted in additional tightening.

Having reference again to FIGS. 6A-7, in an embodiment, the actuator 12 is a linear, double-acting, hydraulic actuator, operatively connected between the upper body 16 and the lower body 18. A hydraulic cylinder 32 of the actuator 12 is pivotally connected at a first pivotal connection 34 to the lower body 18. A rod 36, which extends from the cylinder 32, is pivotally connected at a second pivotal connection 38 to the upper body 16. In an embodiment, the first pivotal connection 34 comprises a first bracket 40 connected to the lower body 18 and a pin 42 which passes through the first bracket 40 and the cylinder 32. The second pivotal connection 38 comprises a clevis 44 which is attached to a distal end 46 of the rod 36 and a bracket 48 connected to the upper body 16. A pin 50 passes through the clevis 44 and the bracket 48. As the rod 36 extends from the cylinder 32 and acts upon the upper body 16, the first and second connections 34, 38 pivot about the pins 42, 50 to permit the hydraulic actuator 12 to rotate with the upper body 16.

In an embodiment, as seen in FIGS. 6A and 8, the upper and lower bodies 16, 18 are oriented relative to one another in a break-out position for loosening the threaded connection between the drill bit 4 and the bit box 6. The action is shown as an indexed rotation having a limited action sufficient to loosen or tighten the drill bit 4 through a small angular rotation. The upper body 16 is aligned with the lower body 18. As shown in FIGS. 6B and 9, extension of the rod 36 from the hydraulic cylinder 32 acts to push the upper body 16 in a clockwise direction to rotate about the common axis X out of alignment with the lower body 18 for loosening the drill bit 4 from the bit box.

Alternatively, as seen in FIGS. 6C and 9, as a starting position the upper and lower bodies 16, 18 are oriented relative to one another in a make-up position for tightening the threaded connection between the drill bit 4 and the bit box 6. The upper body 16 is out of alignment with the lower body 18. As shown in FIG. 6D, the hydraulic cylinder 32 is mounted so that retraction of the rod 36 therein pulls the upper body 16, to which it is connected, in a counterclockwise direction to rotate about the common axis X into alignment with the lower body 18 for tightening the drill bit 4 to the bit box 6.

As can be appreciated by one of skill in the art, by mounting the hydraulic actuator 12 to act in an opposing direction relative to the bit breaker 10, compared to that described, the upper body 16 and the lower body 18 would be aligned in the make-up position and misaligned in the break-out position.

In embodiments, the upper body 16 is rotated into and out of alignment with the lower body 18 from about 30° to about 40° relative to the lower body 18. Such rotation is generally sufficient to loosen or tighten the threaded connection between the drill bit 4 and the bit box 6.

Having reference again to FIGS. 5A and 5C, the bit breaker 10 further comprises a connector 52 for engaging between the lower body 18 and stationary element S, such as the rig floor F, so as to hold the lower body 18 stationary thereto during operation. One such means 52 is a shaped projection 54 extending from a lower surface 56 of the lower body 18 for engaging a corresponding shaped opening (not shown) in the rig floor S. In one embodiment, as seen in FIGS. 8 and 9, the shaped projection 54 is substantially rectangular for engaging a corresponding rectangular opening 61 in the rig floor F or a rotary table 60 situated in the rig floor F.

Having reference to FIGS. 8 and 9, in a system for loosening or tightening the drill bit 4 to a drill string 5 incorporating the mud motor M, a bit breaker 10 to an embodiment of the invention is used in conjunction with at least the lower, stationary tong 8 of a conventional power wrench 70 used for handling tubulars. The lower stationary tong 8 engages the bit box 6 of the mud motor M for holding the normally rotatable bit box 6 stationary and thereafter the body 14 of the bit breaker 10 and the bit 4 housed therein can be co-rotated bi-directionally relative to the stationary member S for either loosening or tightening the threaded connection between the bit box 6 and the drill bit 4.

More particularly, as shown in FIGS. 8 and 9, in a method for making-up a drill string 5, the drill string 5 incorporating the mud motor M is raised and a drill bit 4 is manually hand-threaded onto the mud motor's bit box 6. The bit breaker 10, having the upper and lower bodies 16, 18 oriented relative to one another in the make-up position (FIG. 9), is secured in the rig floor F. The drill string 5 is lowered for positioning by inserting the drill bit 4 into the shaped enclosure 20 in the upper body 16, the bit 4 being held therein for co-rotation with the upper body 16. The lower stationary tong 8 is brought into engagement with the mud motor's bit box 6 and is actuated to hold the bit box 6 stationary. Thereafter, the actuator 12 of the bit breaker 10 is actuated to act on the bit breaker's upper body 16 to rotate about the rotational connection 22 about the common axis X and relative to the lower, stationary body 18 (FIG. 8). Generally, the upper body 16 is indexed from about 30° to about 40° relative to the lower body 18. The drill bit 4 which is housed in the upper body 16 is thereby co-rotated relative to the stationary lower body 18 and the stationary bit box 6 thereabove about the common axis X for tightening the threaded connection between the drill bit 4 and the mud motor's bit box 6.

As described above for conventional drill string or tubular threading, with the bit breaker 10 in the make-up position (FIG. 9) and the actuator 12 being a double-acting hydraulic actuator, the hydraulic cylinder 32 and rod 36 acts to pull the upper body 16 relative to the stationary lower body 18 for rotating the upper body 16 counterclockwise about the rotational connection 22. In an embodiment wherein the upper body 16 is out of alignment with the lower body 18 in the make-up position (FIG. 9), the upper body 16 is pulled to rotate into alignment with the lower stationary body 18 (FIG. 8).

In the case of the methodology for breaking-out a drill string 5 which incorporates a mud motor M, the drill string 5 is raised from the wellbore and tubulars which form the drill string 5 are unthreaded from the drill string 5 in a conventional manner. When the lowermost tubular 72, incorporating the mud motor M and the drill bit 4, is raised above the rig floor F, the bit breaker 10, having the upper and lower bodies 16, 18 oriented relative to one another in the break-out position, is secured to the rig floor F. The drill string 5 is lowered for engaging the drill bit 4 in the shaped enclosure 20 of the upper body 16 for securing the bit 4 therein for co-rotation with the upper body 16. The lower stationary tong 8 of the power wrench 70 is positioned to engage the mud motor's bit box 6 for holding the normally rotatable bit box 6 stationary. Thereafter, the bit breaker's actuator 12 is actuated to act on the upper body 16 causing the upper body 16 and the drill bit 4 housed therein to co-rotate from about 30° to about 40° relative to the stationary lower body 18 for loosening the threaded connection between the drill bit 4 and bit box 6.

As described above for conventional drill string, with the bit breaker 10 in the break-out position and the actuator being a double-acting hydraulic actuator, the hydraulic cylinder 32 and rod 36 act to push the upper body 16 relative to the lower body 18 for rotating the upper body 16 clockwise about the rotational connection 22. In an embodiment wherein the upper body 16 is aligned with the lower body 18 in the break-out position (FIG. 8), the upper body 16 is pushed to rotate out of alignment with the lower stationary body 18 (FIG. 9).

Claims

1. A bit breaker for use in threading a drill bit to or from a mud motor having a lower, normally rotatable bit box, the bit breaker comprising:

a rotatable bit breaker body for housing the drill bit for co-rotation therewith; and
an actuator connected between the bit breaker body and a stationary member,
wherein,
when the mud motor's bit box is held stationary, the actuator is actuable to co-rotate the bit breaker body and drill bit housed therein relative to the stationary member about an axis common to the drill bit, the bit breaker and the mud motor, the body being rotated
in a first direction for loosening a threaded connection between the drill bit and the mud motor's bit box; and
in a second direction for tightening the threaded connection between the drill bit and the mud motor's bit box.

2. The bit breaker of claim 1 wherein the bit breaker body further comprises:

an upper body having an enclosure therein for housing the drill bit;
a lower body held stationary for forming the stationary member; and
a rotational connection operatively connected between the upper rotatable body and the lower stationary body for permitting rotation of the upper body relative to the lower stationary body about the common axis; and
wherein the actuator is connected between the upper body and the lower body for moving the upper body relative to the lower body for rotation about the rotational connection in the first and second directions.

3. The bit breaker of claim 2 wherein

the upper body is oriented relative to the lower body in a break-out position for rotating the upper body in the first direction relative to the lower body; and
the upper body is oriented relative to the lower body in a make-up position for rotating the upper body in the second direction relative to the lower body.

4. The bit breaker of claim 3 wherein the actuator is a double-acting hydraulic actuator further comprising:

a hydraulic cylinder pivotally connected to the lower body; and
a rod operatively connected to the hydraulic cylinder for extension and retraction therefrom, the rod being pivotally connected at a distal end to the upper body wherein
in the break-out position, the rod is extended to push the upper body to move relative to the stationary lower body to rotate in the first direction about the rotational connection; and
in the make-up position, the rod is retracted to pull the upper body to move relative to the stationary lower body to rotate in the second direction about the rotational connection.

5. The bit breaker of claim 3 wherein the upper body is aligned with the lower body in the break-out position and wherein the upper body is rotated about the common axis out of alignment relative to the lower body in the make-up position.

6. The bit breaker of claim 2, for use with conventional threading, wherein when viewed from a top the first direction is a clockwise direction and the second direction is a counter-clockwise direction.

7. The bit breaker of claim 2 further comprising a connector acting between the lower body and a rig floor holding the lower body stationary for forming the stationary member.

8. The bit breaker of claim 7 wherein the connector comprises:

a shaped projection extending from a lower surface of the lower body for engaging a corresponding shaped opening in the rig floor.

9. The bit breaker of claim 2 wherein the rotational connection operatively connected between the upper rotatable body and the lower stationary body further comprises:

an arcuate projection; and
an opposing, arcuate groove, wherein
when the arcuate projection is mated in the arcuate groove and the actuator causes the upper body to move relative to the lower stationary body, the upper body rotates about the common axis.

10. The bit breaker of claim 9 wherein the arcuate projection extends upwardly from an upper surface of the lower body and the arcuate groove is formed on a lower surface of the upper body.

11. The bit breaker of claim 1 wherein the body is rotated about 30 degrees to about 40 degrees relative to the stationary member.

12. A system for applying torque to a drill bit on a mud motor with a lower, normally rotatable bit box, the system comprising:

a bit breaker having a rotatable bit breaker body for housing the drill bit for co-rotation therewith; and an actuator connected between the bit breaker body and a stationary member, the actuator causing the body to rotate relative to the stationary member; and
a tong for holding the bit box stationary,
wherein,
when the tong is actuated to hold the mud motor's bit box stationary, the actuator is actuable to co-rotate the bit breaker body and drill bit housed therein relative to the stationary member about a common axis, the body being rotated in a first direction for loosening a threaded connection between the drill bit and the mud motor's bit box; and in a second direction for tightening the threaded connection between the drill bit and the mud motor's bit box.

13. The system of claim 12 wherein the bit breaker body further comprises:

an upper body having an enclosure therein for housing the drill bit;
a lower body held stationary for forming the stationary member; and
a rotational connection operatively connected between the upper rotatable body and the lower stationary body for permitting rotation of the upper body relative to the lower stationary body about the common axis; and
wherein the actuator is connected between the upper body and the lower body for moving the upper body relative to the lower body for rotation about the rotational connection in the first and second directions.

14. The system of claim 13 wherein

the upper body is oriented relative to the lower body in a break-out position for rotating the upper body in the first direction relative to the lower body; and
the upper body is oriented relative to the lower body in a make-up position for rotating the upper body in the second direction relative to the lower body.

15. The system of claim 13 wherein the actuator is a double-acting hydraulic actuator further comprising:

a hydraulic cylinder pivotally connected to the lower body; and
a rod operatively connected to the hydraulic cylinder for extension and retraction therefrom, the rod being pivotally connected at a distal end to the upper body wherein
in the break-out position, the rod is extended to push the upper body to move relative to the stationary lower body to rotate in a first direction about the rotational connection; and
in the make-up position, the rod is retracted to pull the upper body to move relative to the stationary lower body to rotate in a second direction about the rotational connection.

16. The system of claim 14 wherein the upper body is aligned with the lower body in the break-out position and wherein the upper body is rotated about the common axis out of alignment relative to the lower body in the make-up position.

17. The system of claim 12, for use with conventional threading, wherein the first direction is a clockwise direction and the second direction is a counter-clockwise direction.

18. The system of claim 13 further comprising a connector acting between the lower body and a rig floor holding the lower body stationary for forming the stationary member.

19. The system of claim 18 wherein the connector comprises:

a shaped projection extending from a lower surface of the lower body for engaging a corresponding shaped opening in the rig floor.

20. The system of claim 13 wherein the rotational connection operatively connected between the upper rotatable body and the lower stationary body further comprises:

an arcuate projection; and
an opposing, arcuate groove, wherein when the arcuate projection is mated in the arcuate groove and the actuator causes the upper body to move relative to the lower stationary body, the upper body rotates about the common axis.

21. The system of claim 20 wherein the arcuate projection extends upwardly from an upper surface of the lower body and the arcuate groove is formed on a lower surface of the upper body.

22. The system of claim 12 wherein the body is rotated about 30 degrees to about 40 degrees relative to the stationary member.

23. The system of claim 12 wherein the tong for holding the bit box stationary is a lower stationary tong of a power wrench.

24. A method for applying torque to a drill bit on a mud motor with a lower, normally rotatable bit box for loosening or tightening a threaded connection between the drill bit and the bit box, the method comprising:

providing a bit breaker having a rotatable bit breaker body having an enclosure for housing the drill bit therein for co-rotation therewith; and an actuator connected between the bit breaker body and a stationary member, the actuator being actuable to cause the body to rotate relative to the stationary member about an axis common to the drill bit and the bit box;
inserting the drill bit threaded to the bit box into the enclosure of the bit breaker body;
engaging the bit box for holding the bit box stationary;
actuating the actuator to co-rotate the bit breaker body and the drill bit housed therein in a first direction for loosening a threaded connection between the drill bit and the mud motor's bit box; or in a second direction for tightening the threaded connection between the drill bit and the mud motor's bit box.

25. The method of claim 24 comprising

actuating the actuator to co-rotate the bit breaker body and the drill bit housed therein from about 30 degrees to about 40 degrees relative to the stationary member.

26. The method of claim 24 further comprising

securing the bit breaker body to a rig floor, the rig floor being the stationary member.

27. The method of claim 24 wherein the bit breaker further comprises an upper body for housing the drill bit, a lower body, a rotational connection between the upper and lower bodies and an actuator connected therebetween for rotating the upper body relative to the lower body at the rotational connection about the common axis comprising:

securing the lower body to a rig floor, the lower body acting as the stationary member, wherein
the actuating the actuator moves the upper body relative to the stationary lower body causing the upper body to rotate about the common axis for rotation in the first or second direction.
Patent History
Publication number: 20120234601
Type: Application
Filed: Mar 18, 2011
Publication Date: Sep 20, 2012
Applicant: PRECISION DRILLING CORPORATION (Calgary)
Inventor: HAROLD GRIFFIN (Calgary)
Application Number: 13/051,136
Classifications
Current U.S. Class: Processes (175/57); Tool Removable Or Insertable Through Or Around Driving Or Driven Shaft Or Casing (175/257)
International Classification: E21B 7/00 (20060101); E21B 11/00 (20060101);