US20080185187A1 - Snap ringed bit retainer ring - Google Patents
Snap ringed bit retainer ring Download PDFInfo
- Publication number
- US20080185187A1 US20080185187A1 US12/022,764 US2276408A US2008185187A1 US 20080185187 A1 US20080185187 A1 US 20080185187A1 US 2276408 A US2276408 A US 2276408A US 2008185187 A1 US2008185187 A1 US 2008185187A1
- Authority
- US
- United States
- Prior art keywords
- bit
- retainer
- driver sub
- shank
- disposed around
- Prior art date
- Legal status (The legal status 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 status listed.)
- Abandoned
Links
- 239000002184 metal Substances 0.000 claims description 9
- 238000009434 installation Methods 0.000 description 8
- 238000009527 percussion Methods 0.000 description 7
- 238000005553 drilling Methods 0.000 description 5
- 238000000034 method Methods 0.000 description 5
- 230000008901 benefit Effects 0.000 description 3
- 238000003825 pressing Methods 0.000 description 3
- 230000000717 retained effect Effects 0.000 description 3
- 239000011248 coating agent Substances 0.000 description 2
- 238000000576 coating method Methods 0.000 description 2
- 238000002788 crimping Methods 0.000 description 2
- 239000002360 explosive Substances 0.000 description 2
- 239000000463 material Substances 0.000 description 2
- 238000003466 welding Methods 0.000 description 2
- 239000004568 cement Substances 0.000 description 1
- 230000007797 corrosion Effects 0.000 description 1
- 238000005260 corrosion Methods 0.000 description 1
- 238000005304 joining Methods 0.000 description 1
- 239000000696 magnetic material Substances 0.000 description 1
- 239000010813 municipal solid waste Substances 0.000 description 1
- 230000010355 oscillation Effects 0.000 description 1
- 238000004080 punching Methods 0.000 description 1
- 238000000926 separation method Methods 0.000 description 1
- 238000004513 sizing Methods 0.000 description 1
Images
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
- E21B10/00—Drill bits
- E21B10/36—Percussion drill bits
-
- 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
- E21B17/00—Drilling rods or pipes; Flexible drill strings; Kellies; Drill collars; Sucker rods; Cables; Casings; Tubings
- E21B17/02—Couplings; joints
- E21B17/04—Couplings; joints between rod or the like and bit or between rod and rod or the like
- E21B17/07—Telescoping joints for varying drill string lengths; Shock absorbers
- E21B17/076—Telescoping joints for varying drill string lengths; Shock absorbers between rod or pipe and drill bit
Definitions
- the disclosure relates generally to percussion, or hammer, bits. More specifically, the disclosure relates to a secondary retainer for a downhole hammer bit.
- Percussion bit systems are often used in drilling or boring through the earth's surface.
- a percussion bit system a percussion hammer is used to drive the percussion bit into the ground using the reciprocating action of a piston to energize the bit.
- FIG. 1 illustrates a conventional percussion bit assembly design 100 .
- Percussion hammer assembly 100 comprises a hammer case 101 that connects to a lower end of a drill string (not shown) through a threaded pin connection 145 .
- the lower end of the hammer case 101 is threadedly engaged with driver sub 102 .
- a plurality of splines (not shown) disposed on the driver sub 102 engage a plurality of splines 115 disposed on a shank 112 of a hammer bit 110 , and rotatatively drive the bit 110 .
- a retainer, conventionally a split ring, 113 is disposed around an upper end of the shank 112 of the hammer bit 110 and abuts the driver sub 102 .
- the split ring 113 retains the hammer bit 110 in the hammer assembly 100 .
- the split ring 113 may be held in place, initially, by an elastic ring, or o-ring, 116 to facilitate assembly of the bit and driver sub with the hammer case.
- the split ring is confined by the inner wall of the hammer case 101 to maintain ring-to-bit engagement.
- the upper end of the hammer bit 110 includes a piston strike surface 148 and a foot valve, or blow tube, 147 .
- the lower end of the hammer bit includes a head 111 .
- the hammer assembly includes a control tube 143 and an annular piston chamber 146 . Pressurized air moves a piston 142 in a reciprocating motion inside the annular piston chamber 146 .
- a check valve 144 is used to communicate one-way flow between the control tube 143 and the drill string (not shown).
- the lower end of the piston 142 is adapted to strike the piston strike surface 148 , thereby imparting kinetic energy to the bit 110 .
- the bit is left in the hole when the hammer is extracted.
- the split ring segments lodge in between the driver sub 102 and the borehole wall, preventing the hammer case 101 from screwing back over the driver sub 102 .
- the bit left in the hole has to be retrieved later through a costly fishing operation.
- a segmented retainer sleeve 24 can be used to retain the bit 210 to the driver sub assembly after a driver sub backs off.
- FIGS. 2 and 3 show a conventional hammer assembly 200 comprising a driver sub 202 , a segmented retainer sleeve 24 , a hammer case 201 , and a bit 210 .
- U.S. Pat. No. 5,803,192 shows an example of such a conventional bit retainer.
- the segmented retainer sleeve 24 includes a ring portion 24 A, which seats about a reduced diameter segment 25 of the bit 210 . Ring portion 24 A, in combination with shoulder 24 B, limits reciprocal travel of the drill bit 210 . Skirt extension 26 has a lesser wall thickness than the ring portion 24 A and slidably engages the bit 210 . Skirt extension 26 nests within a counterbore 27 shown formed in the upper end of the driver sub 202 . During a drilling operation, should the driver sub 202 back off, the segmented retainer sleeve 24 should remain in place about the bit because the skirt extension 26 is radially confined.
- Joining the hammer case 201 with the driver sub 202 after the driver sub 202 backs off may be accomplished by rotating the hammer case 201 on the driver sub 202 .
- a drawback of this design is that, as a result of the counterbore 27 in the driver sub 202 , the spline contact area between the splines 33 on the driver sub and the splines (not shown) on the bit 210 is reduced. A reduction in the spline contact area may result in rapid wear and breakage of the splines.
- embodiments disclosed herein relate to a bit retainer system including a bit having a head and a shank, a driver sub disposed around the shank of the bit and adapted to engage a hammer case, a bit retainer disposed around the shank of the bit and abutting an upper end of the driver sub, wherein the bit retainer includes a split ring with a circumferential groove, and a secondary retainer disposed around the bit retainer, wherein the secondary retainer includes a snap ring configured to engage the circumferential groove.
- embodiments disclosed herein relate to a bit retainer system including a bit having a head and a shank, a driver sub disposed around the shank of the bit and adapted to engage a hammer case, a bit retainer disposed around the shank of the bit and abutting an upper end of the driver sub, wherein the bit retainer includes a split ring with a circumferential groove, and a secondary retainer disposed around the bit retainer, wherein the secondary retainer includes a plurality of preformed tabs disposed at selected portions along the retainer.
- embodiments disclosed herein relate to a bit retainer system including a bit having a head and a shank, a driver sub disposed around the shank of the bit and adapted to engage a hammer case, a bit retainer disposed around the shank of the bit and abutting an upper end of the driver sub, wherein the bit retainer includes a split ring with a circumferential groove, and a secondary retainer disposed around the bit retainer, wherein the secondary retainer includes a plurality of preformed webs disposed at selected locations along the retainer.
- embodiments disclosed herein relate to a bit retainer system including a bit having a head and a shank, a driver sub disposed around the shank of the bit and adapted to engage a hammer case, a bit retainer disposed around the shank of the bit and abutting an upper end of the driver sub, wherein the bit retainer includes a split ring with a circumferential groove, and a secondary retainer disposed around the bit retainer in the circumferential groove, wherein the secondary retainer includes a band having a plurality of elastically expandable buckles disposed on a first end and at least one protrusion disposed on a second end of the band.
- FIG. 1 shows a cross-sectional view of a conventional hammer bit system design.
- FIG. 2 shows a cross-sectional view of a conventional drill bit retainer design.
- FIG. 3 shows an assembly view of a conventional drill bit retainer design.
- FIG. 4 shows a bit retainer system in accordance with an embodiment of the present disclosure.
- FIG. 5 shows a bit retainer system in accordance with another embodiment of the present disclosure.
- FIGS. 6A and 6B show a bit retainer system in accordance with another embodiment of the present disclosure.
- FIG. 7 shows a side view and a partial cross-section view of a bit retainer system in accordance with an embodiment of the present disclosure.
- FIGS. 8A-8G show a bit retainer system in accordance with another embodiment of the present disclosure.
- FIG. 9 shows a bit retainer system in accordance with an embodiment of the present disclosure.
- FIGS. 10A and 10B show a bit retainer system in accordance with the embodiment of FIG. 9 .
- FIG. 11 shows a cross-sectional view of a bit retainer system in accordance with another embodiment of the present disclosure.
- FIGS. 12A , 12 B, and 12 C show a bit retainer system in accordance with embodiments of the present disclosure.
- FIG. 13 shows a bit retainer system in accordance with the embodiment of FIGS. 12A , 12 B, and 12 C.
- FIGS. 14A , 14 B, and 14 C show a bit retainer system in accordance with embodiments of the present disclosure.
- the driller may back off the driver sub, or occasionally, the driver sub may back off unintentionally.
- the term “back off” means to unscrew drillstring components downhole.
- the drillstring components which may include a drillpipe, a bottomhole assembly, a driver sub, etc., are coupled by various threadforms known as connections, or tool joints. Any of these drillstring components may unthread or back off.
- the driver sub When a drillstring becomes stuck, the driver sub may unintentionally back off downhole, or it may be necessary to intentionally back off the drillstring from the driver sub to recover as much of the drilling string as possible.
- the back off may be intentionally accomplished by applying reverse torque and detonating an explosive charge inside a selected threaded connection.
- the back off may be intentionally accomplished by applying tension to the drillstring and detonating an explosive charge, thereby allowing the threads to slide by each other without turning.
- a bit retainer usually a split ring configured to retain a drill bit in the driver sub during assembly, often separates from a bit shank. Accordingly, the split ring no longer performs the function of retaining the bit in the driver sub.
- the driller attempts to screw back into the driver sub with the hammer case, the bit is left in the hole. In the event the bit head is lost in the hole, it may be necessary to cement the original wellbore and sidetrack.
- embodiments of the present disclosure relate to a secondary retainer for retaining the bit retainer to the drill bit.
- bit retainer system comprises a secondary retainer disposed around a bit retainer.
- the secondary retainer comprises a perforated metallic deformable ring.
- the bit retainer is disposed around an upper end of a bit shank and abuts a driver sub.
- the bit retainer comprises a segmented retainer ring. In the event the driver sub backs off the hammer assembly, a secondary retainer retains the segmented retainer ring to the drill bit shank.
- Embodiments of the bit retainer system of the present disclosure may prevent the loss of a drill bit at the bottom of the hole and may prevent costly fishing operations to recover lost drill bits.
- FIG. 4 shows an assembled bit retainer system in accordance with an embodiment of the present disclosure.
- the bit retainer system 400 comprises a drill bit 410 , a driver sub 402 , a bit retainer (not shown), and a secondary retainer 413 .
- the secondary retainer 413 comprises a perforated metallic deformable ring. In select embodiments, the perforations may be tabs or webs.
- FIG. 5 shows an exploded view of the bit retainer system of FIG. 4 , in accordance with an embodiment of the invention.
- a driver sub 502 is disposed around a shank 512 of the bit 510 .
- a plurality of splines 523 on the inside diameter of the driver sub 502 engage a plurality of splines 515 disposed axially on the outside diameter of shank 512 to rotatively drive the bit 510 .
- a bit retainer 505 comprises a segmented ring 508 disposed around shank 512 of the bit 510 and abutting the driver sub 502 .
- a secondary retainer 513 is disposed around the bit retainer 505 .
- the secondary retainer 513 comprises a perforated deformable ring 514 .
- the perforated deformable ring 514 may be made from a flat strip of sheet metal that is punched to form a plurality of tabs 517 and then rolled and seam-welded 518 .
- the plurality of tabs 517 are formed at selected locations around the circumference of the perforated deformable ring 514 .
- One of ordinary skill in the art will appreciate that the number of tabs or webs formed and the selected locations of the tabs along the circumference of the perforated deformable ring may vary. The size, number, and location of the webs or tabs may depend on, for example, the dimensions of the drill bit or the load induced on the bit retainer and secondary retainer.
- the plurality of tabs 517 align with a corresponding circumferential groove 519 formed in the bit retainer 505 .
- the circumferential groove 519 may be a continuous channel formed in the outside diameter of the bit retainer 505 .
- the circumferential groove 519 may be a series of grooves or notches that correspond to and align with the plurality of tabs 517 .
- the plurality of tabs 517 are plastically deformed inward, thereby engaging the circumferential groove 519 formed in the bit retainer 505 .
- the plurality of tabs 517 may be deformed by any method known in the art, for example, by pressing a screwdriver against tabs 517 to deform the tabs 517 radially inward. The engagement of the plurality of tabs 517 and the circumferential groove 519 secure the perforated deformable ring 514 to the bit retainer 505 and secure the bit retainer 505 in place around the bit 510 .
- the secondary retainer 513 retains the segmented ring 508 of the bit retainer 505 to the shank 512 of the bit 510 . Accordingly, the drill bit 510 is retained inside the driver sub 502 .
- the driller may recover the driver sub 502 and the drill bit 510 by reconnecting the hammer to the driver sub 502 by threading the hammer case (not shown) back onto the driver sub 502 .
- the secondary retainer 513 may be removed from the bit retainer 505 by radially deforming the plurality of deformed webs radially outward, in the event the drill bit 510 needs to be replaced, or upon disassembly of the driver sub 502 and drill bit 510 from the hammer.
- the secondary retainer 513 may be reused, but this method may be time consuming.
- the secondary retainer 513 may be cut off of the bit retainer 505 by aligning the area to be cut with the split of the segmented ring 508 .
- the plurality of tabs may be cut and pried apart, thereby allowing the secondary retainer 513 to be removed from the bit retainer 505 .
- the secondary retainer 513 includes a perforated ring 514 having a plurality of tabs 517 arranged at selected locations around the circumference of the perforated ring 514 .
- the plurality of tabs 517 are preformed prior to installation onto the bit retainer 505 .
- the secondary retainer 513 is expanded and positioned around the bit retainer 505 , allowing the plurality of deformed tabs 517 to engage the circumferential groove 519 formed in the bit retainer 505 and essentially “snap” into place.
- the engagement of the plurality of tabs 517 and the circumferential groove 519 secures the perforated ring 514 to the bit retainer 505 and secures the bit retainer 505 in place around the bit 510 .
- the secondary retainer 513 retains the segmented ring 508 of the bit retainer 505 to the shank 512 of the bit 510 .
- the drill bit 510 is retained inside the driver sub 502 .
- the driller may recover the driver sub 502 and the drill bit 510 by reconnecting the hammer to the driver sub 502 by threading the hammer case (not shown) back onto the driver sub 502 .
- the bit retainer system 600 comprises a drill bit 610 , a driver sub 602 , a bit retainer 605 , and secondary retainer 613 .
- the bit retainer 605 comprises a segmented ring 608 and the secondary retainer 613 comprises a small gage wire 621 .
- the small gage wire 621 is wrapped around the segmented ring 608 and disposed in a circumferential groove 619 on the outside diameter of the segmented ring 608 .
- the small gage wire 621 retains the bit retainer 605 in its location around the drill bit in the event the driver sub backs off.
- FIG. 6B shows a cross section view of a portion of the bit retainer system 600 of FIG. 6A .
- the secondary retainer 613 comprises a small gage wire 621 wrapped around a bit retainer 605 and disposed in a circumferential groove 619 formed on the outside diameter of the bit retainer 605 .
- the ends (not shown) of the small gage wire 621 may be twisted around each other to prevent the small gage wire 621 from separating from the bit retainer 605 .
- the size of the wire and the number of wraps of wire may vary depending on, for example, the dimensions of the drill bit or the dimensions of the bit retainer.
- a secondary retainer in accordance with the present invention may be formed as shown in FIG. 7 , wherein a secondary retainer 713 is formed with a plurality of tabs 717 and is disposed around bit retainer 705 .
- a circumferential groove 719 is formed in the outside diameter of bit retainer 705 .
- the tabs 717 may be formed in a hemispherical or crescent-like shape with a corresponding hemispherical or crescent-like shaped opening.
- the shape of the tabs is not limited to that shown in FIG. 7 .
- Any shape tab that may be plastically deformed inward to engage a groove on the bit retainer may be used, without departing from the scope of the invention.
- a rectangular shaped tab or a circular shaped tab may be used.
- a secondary retainer may be formed as shown in FIG. 7 , wherein the secondary retainer 713 is formed with a plurality of tabs 717 that are preformed prior to installation around the bit retainer 705 .
- the secondary retainer 713 may be expanded and positioned over the bit retainer 705 , the plurality of deformable tabs 717 engaging the circumferential groove 719 .
- edges of the circumferential groove 719 may include chamfers 723 to allow the preformed tabs 717 to engage the groove 719 .
- a secondary retainer comprises a band 830 with a buckle 832 formed into the band.
- the buckle 832 may be integrally formed into the band 830 .
- the buckle may be attached by means such as welding, riveting, crimping, or other similar means.
- FIG. 8B shows a cross-section view taken through the assembled buckle and part of the bit retainer 805 .
- the bit retainer 805 may be a segmented ring similar to the bit retainer 605 shown in FIG. 6A .
- the band 830 is placed in the circumferential groove 819 of the bit retainer 805 and wrapped around the bit retainer 805 .
- the end 831 of the band 830 is then threaded through the buckle 832 and folded back, shown at 835 , over the buckle 832 .
- the band is then secured by at least one deformable tab 833 , as shown in FIG. 8C .
- the at least one deformable tab 833 is plastically deformed over the end 832 of the band 830 .
- the band 830 and buckle 832 may be protected from damage during handing and in use through at least one lip 840 formed into the bit retainer 805 .
- the band 830 retains the bit retainer 805 to the bit (not shown), thereby preventing separation of the bit from the driver sub (not shown) in the event the driver sub backs off.
- a secondary retainer comprises a band 830 with buckles 832 on a first end of the band 830 as shown in FIG. 8D , and protrusions or “bumps” 834 on a second or opposite end of the band 830 , shown in FIG. 8E .
- buckle 832 and protrusions 834 may be attached to or formed on the band 830 by any means such as welding, riveting, crimping, or other similar means.
- the secondary retainer 813 is placed into the circumferential groove 819 (shown in FIG.
- the band 830 may be protected by a lip 840 formed into the bit retainer 805 , and the end of the band 830 with the protrusions 834 is passed through the buckles 832 of the opposite end of the band 830 .
- either the buckles 832 , the protrusions 834 , or both may elastically deform.
- the protrusions 834 are prevented from “backing out” or passing back through the buckles 832 as shown in FIG. 8F by shoulders 835 of the protrusions 834 that abut the buckles 832 .
- This arrangement prevents the secondary retainer 813 from loosening from around the bit retainer 805 .
- the band 830 may be protected by a lip 840 formed into the bit retainer 805
- a secondary retainer 913 formed with a plurality of webs 937 is disposed around bit retainer 905 .
- a circumferential groove 919 is formed in the outside diameter of bit retainer 905 .
- the plurality of webs 937 are plastically deformed inward 922 and engage the circumferential groove 919 .
- the plurality of webs 937 may be formed by punching holes into a flat strip of sheet metal. The punched strip of sheet metal may then be rolled and seam-welded. The shapes of the holes punched and the corresponding tabs are not limited to that shown in FIG. 9 .
- any shape punch or web may be used without departing from the scope of the invention so long as the webs may be plastically deformed inward to engage a groove on the bit retainer.
- the plurality of webs 937 may be deformed by any method known in the art, for example, by pressing a screwdriver against the webs 937 to deform the webs 937 radially inward.
- the secondary retainer 913 may be formed with a plurality of webs 937 that are preformed prior to installation. During installation, the secondary retainer 913 may be expanded and positioned around bit retainer 905 , thereby allowing the preformed webs to engage the circumferential groove 919 .
- the webs 937 may be preformed using any shape punch as previously mentioned, or any other means known to a those skilled in the art.
- FIG. 10A shows a perspective view of a secondary retainer 1013 , formed in accordance with the embodiment shown in FIG. 9 , disposed around a bit retainer 1005 .
- Bit retainer 1005 comprises a split ring 1008 .
- Secondary retainer 1013 is formed from a flat strip of sheet metal that is punched to form a plurality of webs 1037 , rolled, and seam-welded 1018 . The plurality of webs 1037 are then deformed radially inward 1022 , shown in FIG. 10B , thereby engaging a circumferential groove 1019 on the bit retainer 1005 .
- a secondary retainer 1113 is disposed around the outside diameter of the bit retainer 1105 .
- the secondary retainer 1113 abuts a lip 1140 formed in the bit retainer 1105 .
- the lip 1105 protects the retainer ring 1113 from being displaced or damaged during assembly of the driver sub and drill bit into the hammer case.
- the secondary retainer 1113 may contain a plurality of webs or tabs formed so as to be deformed inward to engage the circumferential groove 1119 formed on the outside diameter of the bit retainer 1105 .
- a secondary retainer 1213 may be formed from a flat strip of sheet metal formed with a plurality of tabs 1217 disposed on at least one circumferential edge 1252 , 1253 .
- the flat strip of metal may then be rolled and seam-welded.
- the plurality of tabs 1217 may be disposed on both circumferential edges 1252 , 1253 of the secondary retainer 1213 , or as shown in FIG. 12C , the plurality of tabs 1217 may be formed on one circumferential edge 1253 .
- the secondary retainer 1213 is disposed around a bit retainer 1205 . In this embodiment, the plurality of tabs 1217 are deformed inward to engage with a corresponding angled surface 1242 on the bit retainer 1205 .
- FIG. 13 shows a perspective view of a secondary retainer 1313 , formed in accordance with the embodiment shown in FIGS. 12A-12C , disposed around a bit retainer 1305 .
- Bit retainer 1305 comprises a split ring 1308 .
- Secondary retainer 1313 is formed with a plurality of tabs 1317 formed on one circumferential edge 1353 . The plurality of tabs 1317 are deformed radially inward and engage with a corresponding angled surface 1342 on the bit retainer 1305 .
- the secondary retainer 1313 engages with the bit retainer 1305 such that, in the event the driver sub backs off, the secondary retainer 1313 retains the segmented rings of the bit retainer in place around the drill bit. Accordingly, when the driver sub is reconnected to the hammer, the drill bit remains assembled to the driver sub.
- a secondary retainer 1413 may be a snap ring 1421 used to secure bit retainer, or split rings 1405 .
- snap ring 1421 may be configured as a circular wire with a gap 1417 between two ends which allows snap ring 1421 to expand and contract as necessary.
- split ring 1405 may be configured with a circumferential groove 1419 to accept snap ring 1421 ( FIG. 14A ).
- FIG. 14C shows an assembled bit retainer system in accordance with embodiments of the present disclosure.
- Bit retainer system 1400 includes a drill bit 1410 , driver sub 1402 , and split ring 1405 having a circumferential groove 1419 configured to receive a snap ring (not shown).
- Snap ring 1421 may include various cross-sectional configurations, including, but not limited to, circular, square, trapezoidal or other shapes known to those skilled in the art.
- snap ring 1421 may be manufactured from metal or other materials known to a person skilled in the art.
- snap ring 1421 may have a coating, such as a corrosion resistant coating, applied to an outer surface.
- snap ring 1421 may be formed from a magnetic material, or alternately, have a magnetic device attached by any method known in the art. The magnetic features may help to hold snap ring 1421 on more securely about split rings 1405 .
- Embodiments of the disclosure may include one or more of the following advantages.
- a metal snap ring as described above may advantageously provide more reliable means of holding the bit retaining rings together during assembly or disassembly and may also hold together the bit retainer in case of a downhole back off. Such an occurrence may leave “junk” or unwanted material in the hole resulting in possibly a costly “fishing” job, or a blind attempt to retrieve components or trash, as well as non-productive drilling time. As is well known in the industry, any downtime costs large amounts of money and is avoided at all costs.
Landscapes
- Engineering & Computer Science (AREA)
- Life Sciences & Earth Sciences (AREA)
- Geology (AREA)
- Mining & Mineral Resources (AREA)
- Mechanical Engineering (AREA)
- Physics & Mathematics (AREA)
- Environmental & Geological Engineering (AREA)
- Fluid Mechanics (AREA)
- General Life Sciences & Earth Sciences (AREA)
- Geochemistry & Mineralogy (AREA)
- Earth Drilling (AREA)
Abstract
A bit retainer system includes a bit having a head and a shank, a driver sub disposed around the shank of the bit and adapted to engage a hammer case, a bit retainer disposed around the shank of the bit and abutting an upper end of the driver sub, wherein the bit retainer includes a split ring with a circumferential groove, and a secondary retainer disposed around the bit retainer, wherein the secondary retainer includes a snap ring configured to engage the circumferential groove.
Description
- The present application is a Continuation-in-Part of U.S. patent application Ser. No. 11/257,294, entitled “Secondary Retainer for a Downhole Hammer Bit” filed Oct. 24, 2005, which is incorporated by reference herein in its entirety.
- 1. Field of the Disclosure
- The disclosure relates generally to percussion, or hammer, bits. More specifically, the disclosure relates to a secondary retainer for a downhole hammer bit.
- 2. Background Art
- Percussion bit systems are often used in drilling or boring through the earth's surface. In a percussion bit system, a percussion hammer is used to drive the percussion bit into the ground using the reciprocating action of a piston to energize the bit.
-
FIG. 1 illustrates a conventional percussionbit assembly design 100.Percussion hammer assembly 100 comprises ahammer case 101 that connects to a lower end of a drill string (not shown) through a threadedpin connection 145. The lower end of thehammer case 101 is threadedly engaged withdriver sub 102. A plurality of splines (not shown) disposed on thedriver sub 102, engage a plurality ofsplines 115 disposed on ashank 112 of ahammer bit 110, and rotatatively drive thebit 110. A retainer, conventionally a split ring, 113 is disposed around an upper end of theshank 112 of thehammer bit 110 and abuts thedriver sub 102. Thesplit ring 113 retains thehammer bit 110 in thehammer assembly 100. Thesplit ring 113 may be held in place, initially, by an elastic ring, or o-ring, 116 to facilitate assembly of the bit and driver sub with the hammer case. The split ring is confined by the inner wall of thehammer case 101 to maintain ring-to-bit engagement. The upper end of thehammer bit 110 includes apiston strike surface 148 and a foot valve, or blow tube, 147. The lower end of the hammer bit includes ahead 111. - The hammer assembly includes a
control tube 143 and anannular piston chamber 146. Pressurized air moves apiston 142 in a reciprocating motion inside theannular piston chamber 146. Acheck valve 144 is used to communicate one-way flow between thecontrol tube 143 and the drill string (not shown). The lower end of thepiston 142 is adapted to strike thepiston strike surface 148, thereby imparting kinetic energy to thebit 110. - During certain operations performed with a hammer tool, it may be necessary to reverse drill pipe rotation, thereby causing the
driver sub 102 to back off, or unthread, from thehammer case 101. Occasionally, a driver sub will unintentionally back off downhole due to torsional oscillations, known as “stick-slip”, of the drill string. If the driver sub backs off, thebit 110 and thedriver sub 102 remain at the bottom of the borehole. When this occurs, theelastic ring 116 that restricts the movement of thesplit ring 113 during installation often fails and permits the split ring to fall away out of engagement with the bit. Consequently, the split ring does not fulfill the function of retaining the bit in the driver sub assembly. Therefore, when the driller attempts to screw back into the driver sub with the hammer case, the bit is left in the hole when the hammer is extracted. Sometimes the split ring segments lodge in between thedriver sub 102 and the borehole wall, preventing thehammer case 101 from screwing back over thedriver sub 102. The bit left in the hole has to be retrieved later through a costly fishing operation. - A segmented
retainer sleeve 24, as shown inFIGS. 2 and 3 can be used to retain thebit 210 to the driver sub assembly after a driver sub backs off.FIGS. 2 and 3 show aconventional hammer assembly 200 comprising adriver sub 202, a segmentedretainer sleeve 24, ahammer case 201, and abit 210. U.S. Pat. No. 5,803,192 shows an example of such a conventional bit retainer. - The segmented
retainer sleeve 24, as shown inFIGS. 2 and 3 , includes aring portion 24A, which seats about a reduceddiameter segment 25 of thebit 210.Ring portion 24A, in combination withshoulder 24B, limits reciprocal travel of thedrill bit 210.Skirt extension 26 has a lesser wall thickness than thering portion 24A and slidably engages thebit 210.Skirt extension 26 nests within acounterbore 27 shown formed in the upper end of thedriver sub 202. During a drilling operation, should thedriver sub 202 back off, the segmentedretainer sleeve 24 should remain in place about the bit because theskirt extension 26 is radially confined. Joining thehammer case 201 with thedriver sub 202 after thedriver sub 202 backs off may be accomplished by rotating thehammer case 201 on thedriver sub 202. A drawback of this design is that, as a result of thecounterbore 27 in thedriver sub 202, the spline contact area between thesplines 33 on the driver sub and the splines (not shown) on thebit 210 is reduced. A reduction in the spline contact area may result in rapid wear and breakage of the splines. - Accordingly, there exists a need for a downhole hammer bit retainer that retains the bit within the driver sub in the event the driver sub backs off downhole and that maintains the mechanical integrity of the driver sub and drill bit.
- In one aspect, embodiments disclosed herein relate to a bit retainer system including a bit having a head and a shank, a driver sub disposed around the shank of the bit and adapted to engage a hammer case, a bit retainer disposed around the shank of the bit and abutting an upper end of the driver sub, wherein the bit retainer includes a split ring with a circumferential groove, and a secondary retainer disposed around the bit retainer, wherein the secondary retainer includes a snap ring configured to engage the circumferential groove.
- In other aspects, embodiments disclosed herein relate to a bit retainer system including a bit having a head and a shank, a driver sub disposed around the shank of the bit and adapted to engage a hammer case, a bit retainer disposed around the shank of the bit and abutting an upper end of the driver sub, wherein the bit retainer includes a split ring with a circumferential groove, and a secondary retainer disposed around the bit retainer, wherein the secondary retainer includes a plurality of preformed tabs disposed at selected portions along the retainer.
- In other aspects, embodiments disclosed herein relate to a bit retainer system including a bit having a head and a shank, a driver sub disposed around the shank of the bit and adapted to engage a hammer case, a bit retainer disposed around the shank of the bit and abutting an upper end of the driver sub, wherein the bit retainer includes a split ring with a circumferential groove, and a secondary retainer disposed around the bit retainer, wherein the secondary retainer includes a plurality of preformed webs disposed at selected locations along the retainer.
- In other aspects, embodiments disclosed herein relate to a bit retainer system including a bit having a head and a shank, a driver sub disposed around the shank of the bit and adapted to engage a hammer case, a bit retainer disposed around the shank of the bit and abutting an upper end of the driver sub, wherein the bit retainer includes a split ring with a circumferential groove, and a secondary retainer disposed around the bit retainer in the circumferential groove, wherein the secondary retainer includes a band having a plurality of elastically expandable buckles disposed on a first end and at least one protrusion disposed on a second end of the band.
- Other aspects and advantages of the disclosure will be apparent from the following description and the appended claims.
-
FIG. 1 shows a cross-sectional view of a conventional hammer bit system design. -
FIG. 2 shows a cross-sectional view of a conventional drill bit retainer design. -
FIG. 3 shows an assembly view of a conventional drill bit retainer design. -
FIG. 4 shows a bit retainer system in accordance with an embodiment of the present disclosure. -
FIG. 5 shows a bit retainer system in accordance with another embodiment of the present disclosure. -
FIGS. 6A and 6B show a bit retainer system in accordance with another embodiment of the present disclosure. -
FIG. 7 shows a side view and a partial cross-section view of a bit retainer system in accordance with an embodiment of the present disclosure. -
FIGS. 8A-8G show a bit retainer system in accordance with another embodiment of the present disclosure. -
FIG. 9 shows a bit retainer system in accordance with an embodiment of the present disclosure. -
FIGS. 10A and 10B show a bit retainer system in accordance with the embodiment ofFIG. 9 . -
FIG. 11 shows a cross-sectional view of a bit retainer system in accordance with another embodiment of the present disclosure. -
FIGS. 12A , 12B, and 12C show a bit retainer system in accordance with embodiments of the present disclosure. -
FIG. 13 shows a bit retainer system in accordance with the embodiment ofFIGS. 12A , 12B, and 12C. -
FIGS. 14A , 14B, and 14C show a bit retainer system in accordance with embodiments of the present disclosure. - When using a hammer drill, the driller may back off the driver sub, or occasionally, the driver sub may back off unintentionally. As used herein, the term “back off” means to unscrew drillstring components downhole. The drillstring components, which may include a drillpipe, a bottomhole assembly, a driver sub, etc., are coupled by various threadforms known as connections, or tool joints. Any of these drillstring components may unthread or back off. When a drillstring becomes stuck, the driver sub may unintentionally back off downhole, or it may be necessary to intentionally back off the drillstring from the driver sub to recover as much of the drilling string as possible. The back off may be intentionally accomplished by applying reverse torque and detonating an explosive charge inside a selected threaded connection. Alternatively, the back off may be intentionally accomplished by applying tension to the drillstring and detonating an explosive charge, thereby allowing the threads to slide by each other without turning. When a driver sub backs off, a bit retainer, usually a split ring configured to retain a drill bit in the driver sub during assembly, often separates from a bit shank. Accordingly, the split ring no longer performs the function of retaining the bit in the driver sub. Thus, when the driller attempts to screw back into the driver sub with the hammer case, the bit is left in the hole. In the event the bit head is lost in the hole, it may be necessary to cement the original wellbore and sidetrack. Sidetracking, or drilling a secondary wellbore away from an original wellbore, is an expensive operation and may cost around 20,000 to 50,000 dollars. Additionally, this results in a hole which thereafter has an undesirable dogleg. In one aspect, embodiments of the present disclosure relate to a secondary retainer for retaining the bit retainer to the drill bit.
- Select embodiments of the present disclosure, as described below, include a bit retainer system. In one embodiment, the bit retainer system comprises a secondary retainer disposed around a bit retainer. In some embodiments, the secondary retainer comprises a perforated metallic deformable ring. The bit retainer is disposed around an upper end of a bit shank and abuts a driver sub. In some embodiments, the bit retainer comprises a segmented retainer ring. In the event the driver sub backs off the hammer assembly, a secondary retainer retains the segmented retainer ring to the drill bit shank. When the driller attempts to thread the hammer back on to the driver sub, the drill bit is retained in the driver sub, and the entire assembly may be reconnected to the hammer. Embodiments of the bit retainer system of the present disclosure may prevent the loss of a drill bit at the bottom of the hole and may prevent costly fishing operations to recover lost drill bits.
-
FIG. 4 shows an assembled bit retainer system in accordance with an embodiment of the present disclosure. In this embodiment, thebit retainer system 400 comprises adrill bit 410, adriver sub 402, a bit retainer (not shown), and asecondary retainer 413. In this embodiment, thesecondary retainer 413 comprises a perforated metallic deformable ring. In select embodiments, the perforations may be tabs or webs. -
FIG. 5 shows an exploded view of the bit retainer system ofFIG. 4 , in accordance with an embodiment of the invention. Adriver sub 502 is disposed around ashank 512 of thebit 510. A plurality ofsplines 523 on the inside diameter of thedriver sub 502 engage a plurality ofsplines 515 disposed axially on the outside diameter ofshank 512 to rotatively drive thebit 510. In this embodiment, abit retainer 505 comprises asegmented ring 508 disposed aroundshank 512 of thebit 510 and abutting thedriver sub 502. Asecondary retainer 513 is disposed around thebit retainer 505. - In this embodiment, the
secondary retainer 513 comprises a perforateddeformable ring 514. The perforateddeformable ring 514 may be made from a flat strip of sheet metal that is punched to form a plurality of tabs 517 and then rolled and seam-welded 518. The plurality of tabs 517 are formed at selected locations around the circumference of the perforateddeformable ring 514. One of ordinary skill in the art will appreciate that the number of tabs or webs formed and the selected locations of the tabs along the circumference of the perforated deformable ring may vary. The size, number, and location of the webs or tabs may depend on, for example, the dimensions of the drill bit or the load induced on the bit retainer and secondary retainer. In one embodiment, the plurality of tabs 517 align with a correspondingcircumferential groove 519 formed in thebit retainer 505. In one embodiment, thecircumferential groove 519 may be a continuous channel formed in the outside diameter of thebit retainer 505. In another embodiment, thecircumferential groove 519 may be a series of grooves or notches that correspond to and align with the plurality of tabs 517. - After assembling the
drill bit 510,driver sub 502,bit retainer 505, and thesecondary retainer 513, the plurality of tabs 517 are plastically deformed inward, thereby engaging thecircumferential groove 519 formed in thebit retainer 505. One of ordinary skill in the art will appreciate that the plurality of tabs 517 may be deformed by any method known in the art, for example, by pressing a screwdriver against tabs 517 to deform the tabs 517 radially inward. The engagement of the plurality of tabs 517 and thecircumferential groove 519 secure the perforateddeformable ring 514 to thebit retainer 505 and secure thebit retainer 505 in place around thebit 510. In the event thedriver sub 502 backs off the hammer, thesecondary retainer 513 retains the segmentedring 508 of thebit retainer 505 to theshank 512 of thebit 510. Accordingly, thedrill bit 510 is retained inside thedriver sub 502. The driller may recover thedriver sub 502 and thedrill bit 510 by reconnecting the hammer to thedriver sub 502 by threading the hammer case (not shown) back onto thedriver sub 502. - In accordance with an embodiment of the invention, the
secondary retainer 513 may be removed from thebit retainer 505 by radially deforming the plurality of deformed webs radially outward, in the event thedrill bit 510 needs to be replaced, or upon disassembly of thedriver sub 502 anddrill bit 510 from the hammer. Thesecondary retainer 513 may be reused, but this method may be time consuming. In accordance with an embodiment of the invention, thesecondary retainer 513 may be cut off of thebit retainer 505 by aligning the area to be cut with the split of thesegmented ring 508. In another embodiment, the plurality of tabs may be cut and pried apart, thereby allowing thesecondary retainer 513 to be removed from thebit retainer 505. - In certain embodiments, the
secondary retainer 513 includes aperforated ring 514 having a plurality of tabs 517 arranged at selected locations around the circumference of theperforated ring 514. The plurality of tabs 517 are preformed prior to installation onto thebit retainer 505. During installation, thesecondary retainer 513 is expanded and positioned around thebit retainer 505, allowing the plurality of deformed tabs 517 to engage thecircumferential groove 519 formed in thebit retainer 505 and essentially “snap” into place. The engagement of the plurality of tabs 517 and thecircumferential groove 519 secures theperforated ring 514 to thebit retainer 505 and secures thebit retainer 505 in place around thebit 510. In the event thedriver sub 502 backs off the hammer, thesecondary retainer 513 retains the segmentedring 508 of thebit retainer 505 to theshank 512 of thebit 510. Accordingly, thedrill bit 510 is retained inside thedriver sub 502. The driller may recover thedriver sub 502 and thedrill bit 510 by reconnecting the hammer to thedriver sub 502 by threading the hammer case (not shown) back onto thedriver sub 502. - In another embodiment, as shown in
FIG. 6A , thebit retainer system 600 comprises adrill bit 610, adriver sub 602, abit retainer 605, andsecondary retainer 613. In this embodiment, thebit retainer 605 comprises asegmented ring 608 and thesecondary retainer 613 comprises asmall gage wire 621. Thesmall gage wire 621 is wrapped around thesegmented ring 608 and disposed in acircumferential groove 619 on the outside diameter of thesegmented ring 608. Thesmall gage wire 621 retains thebit retainer 605 in its location around the drill bit in the event the driver sub backs off. -
FIG. 6B shows a cross section view of a portion of thebit retainer system 600 ofFIG. 6A . In this embodiment, thesecondary retainer 613 comprises asmall gage wire 621 wrapped around abit retainer 605 and disposed in acircumferential groove 619 formed on the outside diameter of thebit retainer 605. In one embodiment, the ends (not shown) of thesmall gage wire 621 may be twisted around each other to prevent thesmall gage wire 621 from separating from thebit retainer 605. One of ordinary skill in the art will appreciate that the size of the wire and the number of wraps of wire may vary depending on, for example, the dimensions of the drill bit or the dimensions of the bit retainer. - In another embodiment, a secondary retainer in accordance with the present invention may be formed as shown in
FIG. 7 , wherein asecondary retainer 713 is formed with a plurality oftabs 717 and is disposed aroundbit retainer 705. A circumferential groove 719 is formed in the outside diameter ofbit retainer 705. Once thesecondary retainer 713 is assembled around thebit retainer 705, the plurality oftabs 717 are plastically deformed inward 722 and engage the circumferential groove 719. One of ordinary skill in the art will appreciate that the plurality oftabs 717 may be deformed by any method known in the art, for example, by pressing a screwdriver againsttabs 717 to deform thetabs 717 radially inward. In one embodiment, as shown inFIG. 7 , thetabs 717 may be formed in a hemispherical or crescent-like shape with a corresponding hemispherical or crescent-like shaped opening. The shape of the tabs is not limited to that shown inFIG. 7 . One of ordinary skill in the art will appreciate that any shape tab that may be plastically deformed inward to engage a groove on the bit retainer may be used, without departing from the scope of the invention. For example, a rectangular shaped tab or a circular shaped tab may be used. - In certain embodiments, a secondary retainer may be formed as shown in
FIG. 7 , wherein thesecondary retainer 713 is formed with a plurality oftabs 717 that are preformed prior to installation around thebit retainer 705. During installation, thesecondary retainer 713 may be expanded and positioned over thebit retainer 705, the plurality ofdeformable tabs 717 engaging the circumferential groove 719. Further, edges of the circumferential groove 719 may includechamfers 723 to allow the preformedtabs 717 to engage the groove 719. - In another embodiment, as shown in
FIGS. 8A , 8B, and 8C, a secondary retainer comprises aband 830 with abuckle 832 formed into the band. As shown inFIG. 8A , thebuckle 832 may be integrally formed into theband 830. One of ordinary skill in the art will appreciate, however, that the buckle may be attached by means such as welding, riveting, crimping, or other similar means.FIG. 8B shows a cross-section view taken through the assembled buckle and part of thebit retainer 805. Thebit retainer 805 may be a segmented ring similar to thebit retainer 605 shown inFIG. 6A . In this embodiment, theband 830 is placed in thecircumferential groove 819 of thebit retainer 805 and wrapped around thebit retainer 805. Theend 831 of theband 830 is then threaded through thebuckle 832 and folded back, shown at 835, over thebuckle 832. The band is then secured by at least onedeformable tab 833, as shown inFIG. 8C . The at least onedeformable tab 833 is plastically deformed over theend 832 of theband 830. As shown inFIG. 8B , theband 830 and buckle 832 may be protected from damage during handing and in use through at least onelip 840 formed into thebit retainer 805. Theband 830 retains thebit retainer 805 to the bit (not shown), thereby preventing separation of the bit from the driver sub (not shown) in the event the driver sub backs off. - In another embodiment, as shown in
FIGS. 8D-8G , a secondary retainer comprises aband 830 withbuckles 832 on a first end of theband 830 as shown inFIG. 8D , and protrusions or “bumps” 834 on a second or opposite end of theband 830, shown inFIG. 8E . One of ordinary skill in the art will appreciate that thebuckle 832 andprotrusions 834 may be attached to or formed on theband 830 by any means such as welding, riveting, crimping, or other similar means. During installation, thesecondary retainer 813 is placed into the circumferential groove 819 (shown inFIG. 8G ) around thebit retainer 805, and the end of theband 830 with theprotrusions 834 is passed through thebuckles 832 of the opposite end of theband 830. As theprotrusions 834 pass through thebuckles 832, either thebuckles 832, theprotrusions 834, or both may elastically deform. After theprotrusions 834 are fully engaged with thebuckles 832, theprotrusions 834 are prevented from “backing out” or passing back through thebuckles 832 as shown inFIG. 8F byshoulders 835 of theprotrusions 834 that abut thebuckles 832. This arrangement prevents thesecondary retainer 813 from loosening from around thebit retainer 805. As previously described, theband 830 may be protected by alip 840 formed into thebit retainer 805 - In another embodiment, shown in
FIG. 9 , asecondary retainer 913 formed with a plurality ofwebs 937 is disposed aroundbit retainer 905. Acircumferential groove 919 is formed in the outside diameter ofbit retainer 905. Once thesecondary retainer 913 is assembled around thebit retainer 905, the plurality ofwebs 937 are plastically deformed inward 922 and engage thecircumferential groove 919. In the embodiment shown inFIG. 9 , the plurality ofwebs 937 may be formed by punching holes into a flat strip of sheet metal. The punched strip of sheet metal may then be rolled and seam-welded. The shapes of the holes punched and the corresponding tabs are not limited to that shown inFIG. 9 . One of ordinary skill in the art will appreciate that any shape punch or web may be used without departing from the scope of the invention so long as the webs may be plastically deformed inward to engage a groove on the bit retainer. One of ordinary skill in the art will appreciate that the plurality ofwebs 937 may be deformed by any method known in the art, for example, by pressing a screwdriver against thewebs 937 to deform thewebs 937 radially inward. - In certain embodiments, the
secondary retainer 913 may be formed with a plurality ofwebs 937 that are preformed prior to installation. During installation, thesecondary retainer 913 may be expanded and positioned aroundbit retainer 905, thereby allowing the preformed webs to engage thecircumferential groove 919. Thewebs 937 may be preformed using any shape punch as previously mentioned, or any other means known to a those skilled in the art. -
FIG. 10A shows a perspective view of asecondary retainer 1013, formed in accordance with the embodiment shown inFIG. 9 , disposed around abit retainer 1005.Bit retainer 1005 comprises asplit ring 1008.Secondary retainer 1013 is formed from a flat strip of sheet metal that is punched to form a plurality ofwebs 1037, rolled, and seam-welded 1018. The plurality ofwebs 1037 are then deformed radially inward 1022, shown inFIG. 10B , thereby engaging acircumferential groove 1019 on thebit retainer 1005. - In another embodiment, shown in
FIG. 11 , asecondary retainer 1113 is disposed around the outside diameter of thebit retainer 1105. In this embodiment, thesecondary retainer 1113 abuts alip 1140 formed in thebit retainer 1105. Thelip 1105 protects theretainer ring 1113 from being displaced or damaged during assembly of the driver sub and drill bit into the hammer case. Thesecondary retainer 1113 may contain a plurality of webs or tabs formed so as to be deformed inward to engage thecircumferential groove 1119 formed on the outside diameter of thebit retainer 1105. - In another embodiment, shown in
FIGS. 12A-12C , asecondary retainer 1213 may be formed from a flat strip of sheet metal formed with a plurality oftabs 1217 disposed on at least onecircumferential edge FIG. 12B , the plurality oftabs 1217 may be disposed on bothcircumferential edges secondary retainer 1213, or as shown inFIG. 12C , the plurality oftabs 1217 may be formed on onecircumferential edge 1253. Thesecondary retainer 1213 is disposed around abit retainer 1205. In this embodiment, the plurality oftabs 1217 are deformed inward to engage with a correspondingangled surface 1242 on thebit retainer 1205. -
FIG. 13 shows a perspective view of asecondary retainer 1313, formed in accordance with the embodiment shown inFIGS. 12A-12C , disposed around abit retainer 1305.Bit retainer 1305 comprises asplit ring 1308.Secondary retainer 1313 is formed with a plurality oftabs 1317 formed on onecircumferential edge 1353. The plurality oftabs 1317 are deformed radially inward and engage with a correspondingangled surface 1342 on thebit retainer 1305. Thesecondary retainer 1313 engages with thebit retainer 1305 such that, in the event the driver sub backs off, thesecondary retainer 1313 retains the segmented rings of the bit retainer in place around the drill bit. Accordingly, when the driver sub is reconnected to the hammer, the drill bit remains assembled to the driver sub. - In select embodiments, as shown in
FIGS. 14A and 14B , asecondary retainer 1413 may be asnap ring 1421 used to secure bit retainer, or split rings 1405. As used herein,snap ring 1421 may be configured as a circular wire with agap 1417 between two ends which allowssnap ring 1421 to expand and contract as necessary. As shown inFIG. 14B , splitring 1405 may be configured with acircumferential groove 1419 to accept snap ring 1421 (FIG. 14A ). As such,snap ring 1421 may be assembled ontosplit ring 1405 by initially expandingsnap ring 1421 to fit over the outer circumference ofsplit ring 1405, positioningsnap ring 1421 overgroove 1419, and allowingsnap ring 1421 to contract intogroove 1419.FIG. 14C shows an assembled bit retainer system in accordance with embodiments of the present disclosure.Bit retainer system 1400 includes adrill bit 1410,driver sub 1402, and splitring 1405 having acircumferential groove 1419 configured to receive a snap ring (not shown). -
Snap ring 1421 may include various cross-sectional configurations, including, but not limited to, circular, square, trapezoidal or other shapes known to those skilled in the art. One of ordinary skill in the art will understand the appropriate sizing ofsnap ring 1421 andcircumferential groove 1419 that is required to holdsplit ring 1405 together. Further,snap ring 1421 may be manufactured from metal or other materials known to a person skilled in the art. Further, in certain embodiments,snap ring 1421 may have a coating, such as a corrosion resistant coating, applied to an outer surface. In still further embodiments,snap ring 1421 may be formed from a magnetic material, or alternately, have a magnetic device attached by any method known in the art. The magnetic features may help to holdsnap ring 1421 on more securely about split rings 1405. - Embodiments of the disclosure may include one or more of the following advantages. A bit retainer system with a secondary retainer to retain the bit retainer in a position necessary for retaining the bit to the driver sub during assembly of the hammer. A bit retainer system with a secondary retainer to retain the bit retainer in a position necessary for retaining the bit to the driver sub in the event the driver sub backs off. Accordingly, the bit retainer system may decrease the time for recovering a driver sub and drill bit. Additionally, the bit retainer system may decrease the cost of reconnecting the driver sub and drill bit to the hammer after the driver sub backs off. Further, embodiments disclosed herein may provide a secondary retainer capable of withstanding increased downhole temperatures, thereby eliminating failures due to temperatures downhole.
- A metal snap ring as described above, may advantageously provide more reliable means of holding the bit retaining rings together during assembly or disassembly and may also hold together the bit retainer in case of a downhole back off. Such an occurrence may leave “junk” or unwanted material in the hole resulting in possibly a costly “fishing” job, or a blind attempt to retrieve components or trash, as well as non-productive drilling time. As is well known in the industry, any downtime costs large amounts of money and is avoided at all costs.
- While the disclosure has been described with respect to a limited number of embodiments, those skilled in the art, having benefit of this disclosure, will appreciate that other embodiments can be devised which do not depart from the scope of the disclosure as disclosed herein. Accordingly, the scope of the disclosure should be limited only by the attached claims.
Claims (12)
1. A bit retainer system comprising:
a bit having a head and a shank;
a driver sub disposed around the shank of the bit and adapted to engage a hammer case;
a bit retainer disposed around the shank of the bit and abutting an upper end of the driver sub, wherein the bit retainer comprises a split ring with a circumferential groove; and
a secondary retainer disposed around the bit retainer, wherein the secondary retainer comprises a snap ring configured to engage the circumferential groove.
2. The bit retainer system of claim 1 , wherein the snap ring is metal.
3. The bit retainer system of claim 1 , wherein the snap ring is magnetic.
4. The bit retainer system of claim 1 , wherein the snap ring is elastically expandable.
5. A bit retainer system comprising:
a bit having a head and a shank;
a driver sub disposed around the shank of the bit and adapted to engage a hammer case;
a bit retainer disposed around the shank of the bit and abutting an upper end of the driver sub, wherein the bit retainer comprises a split ring with a circumferential groove; and
a secondary retainer disposed around the bit retainer, wherein the secondary retainer comprises a plurality of preformed tabs disposed at selected portions along the retainer.
6. The bit retainer system of claim 5 , wherein the secondary retainer is configured to elastically expand, thereby allowing the preformed tabs to engage the circumferential groove of the split rings.
7. The bit retainer system of claim 5 , wherein the split rings comprise a chamfer on at least one edge of the circumferential groove.
8. A bit retainer system comprising:
a bit having a head and a shank;
a driver sub disposed around the shank of the bit and adapted to engage a hammer case;
a bit retainer disposed around the shank of the bit and abutting an upper end of the driver sub, wherein the bit retainer comprises a split ring with a circumferential groove; and
a secondary retainer disposed around the bit retainer, wherein the secondary retainer comprises a plurality of preformed webs disposed at selected locations along the retainer.
9. The bit retainer system of claim 8 , wherein the secondary retainer is configured to elastically expand, thereby allowing the plurality of preformed webs to engage the circumferential groove of the split rings.
10. The bit retainer system of claim 8 , wherein the split ring comprises a chamfer on at least one edge of the circumferential groove.
11. A bit retainer system comprising:
a bit having a head and a shank;
a driver sub disposed around the shank of the bit and adapted to engage a hammer case;
a bit retainer disposed around the shank of the bit and abutting an upper end of the driver sub, wherein the bit retainer comprises a split ring with a circumferential groove; and
a secondary retainer disposed around the bit retainer in the circumferential groove, wherein the secondary retainer comprises a band having a plurality of elastically expandable buckles disposed on a first end and at least one protrusion disposed on a second end of the band.
12. The bit retainer system of claim 11 , wherein the protrusions are configured to engage the buckles and secure the band around the bit retainer.
Priority Applications (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
US12/022,764 US20080185187A1 (en) | 2005-10-24 | 2008-01-30 | Snap ringed bit retainer ring |
Applications Claiming Priority (2)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
US11/257,294 US7343989B2 (en) | 2005-10-24 | 2005-10-24 | Secondary retainer for a downhole hammer bit |
US12/022,764 US20080185187A1 (en) | 2005-10-24 | 2008-01-30 | Snap ringed bit retainer ring |
Related Parent Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
US11/257,294 Continuation-In-Part US7343989B2 (en) | 2005-10-24 | 2005-10-24 | Secondary retainer for a downhole hammer bit |
Publications (1)
Publication Number | Publication Date |
---|---|
US20080185187A1 true US20080185187A1 (en) | 2008-08-07 |
Family
ID=39675199
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
US12/022,764 Abandoned US20080185187A1 (en) | 2005-10-24 | 2008-01-30 | Snap ringed bit retainer ring |
Country Status (1)
Country | Link |
---|---|
US (1) | US20080185187A1 (en) |
Cited By (7)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US20080210468A1 (en) * | 2007-01-29 | 2008-09-04 | Michael Tjader | Drill head connection and method |
US20100187016A1 (en) * | 2009-01-28 | 2010-07-29 | Smith International, Inc. | Percussion Hammer Bit With a Driver Sub Including a Guide Sleeve Portion |
US20130153208A1 (en) * | 2011-12-14 | 2013-06-20 | Ross Bassinger | Downhole Tool Retainer And Guide Ring And Methods Of Fabricating The Same |
US20130319772A1 (en) * | 2012-06-01 | 2013-12-05 | Smith International, Inc. | Hammer bit locking mechanism |
US9357572B2 (en) | 2008-10-22 | 2016-05-31 | Huawei Technologies Co., Ltd. | Method, device, and system for transmitting packet switched services |
WO2016122468A1 (en) * | 2015-01-28 | 2016-08-04 | Halliburton Energy Services, Inc. | Motor shaft transmission interference apparatus |
US10760351B2 (en) | 2015-04-17 | 2020-09-01 | Halliburton Energy Services, Inc. | Coupling mechanism for driveshaft transmission assembly |
Citations (9)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US2942579A (en) * | 1956-04-17 | 1960-06-28 | Ingersoll Rand Co | Rock drill |
US3343890A (en) * | 1965-01-18 | 1967-09-26 | Exxon Production Research Co | Apparatus for reducing casing wear during drilling operations |
US5390749A (en) * | 1994-01-31 | 1995-02-21 | Ingersoll-Rand Company | Apparatus for positioning a split retaining ring in a down-hole percussive drill |
US5566771A (en) * | 1995-08-30 | 1996-10-22 | Ingersoll-Rand Company | Reversible casing for a self-lubricating, fluid-actuated, percussive down-the-hole drill |
US5782500A (en) * | 1995-05-26 | 1998-07-21 | Mate; Robert James | Passageway aligned coupling and process |
US6464023B2 (en) * | 1999-01-27 | 2002-10-15 | William N. Patterson | Hydraulic in-the-hole percussion rock drill |
US6516903B2 (en) * | 2000-03-21 | 2003-02-11 | Weatherford/Lamb, Inc. | Drill bit stabilizer device |
US6789632B2 (en) * | 2002-03-01 | 2004-09-14 | Halco Drilling International Limited | Rock drilling apparatus |
US7215059B1 (en) * | 1999-04-01 | 2007-05-08 | Daimlerchrysler Ag | Reluctance motor with at least two salient poles each provided with an exciter winding, and method for manufacturing the stator of such reluctance motor |
-
2008
- 2008-01-30 US US12/022,764 patent/US20080185187A1/en not_active Abandoned
Patent Citations (9)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US2942579A (en) * | 1956-04-17 | 1960-06-28 | Ingersoll Rand Co | Rock drill |
US3343890A (en) * | 1965-01-18 | 1967-09-26 | Exxon Production Research Co | Apparatus for reducing casing wear during drilling operations |
US5390749A (en) * | 1994-01-31 | 1995-02-21 | Ingersoll-Rand Company | Apparatus for positioning a split retaining ring in a down-hole percussive drill |
US5782500A (en) * | 1995-05-26 | 1998-07-21 | Mate; Robert James | Passageway aligned coupling and process |
US5566771A (en) * | 1995-08-30 | 1996-10-22 | Ingersoll-Rand Company | Reversible casing for a self-lubricating, fluid-actuated, percussive down-the-hole drill |
US6464023B2 (en) * | 1999-01-27 | 2002-10-15 | William N. Patterson | Hydraulic in-the-hole percussion rock drill |
US7215059B1 (en) * | 1999-04-01 | 2007-05-08 | Daimlerchrysler Ag | Reluctance motor with at least two salient poles each provided with an exciter winding, and method for manufacturing the stator of such reluctance motor |
US6516903B2 (en) * | 2000-03-21 | 2003-02-11 | Weatherford/Lamb, Inc. | Drill bit stabilizer device |
US6789632B2 (en) * | 2002-03-01 | 2004-09-14 | Halco Drilling International Limited | Rock drilling apparatus |
Cited By (17)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US8561721B2 (en) * | 2007-01-29 | 2013-10-22 | Tt Technologies, Inc. | Drill head connection |
US20080210468A1 (en) * | 2007-01-29 | 2008-09-04 | Michael Tjader | Drill head connection and method |
US9357572B2 (en) | 2008-10-22 | 2016-05-31 | Huawei Technologies Co., Ltd. | Method, device, and system for transmitting packet switched services |
US20100187016A1 (en) * | 2009-01-28 | 2010-07-29 | Smith International, Inc. | Percussion Hammer Bit With a Driver Sub Including a Guide Sleeve Portion |
US8312944B2 (en) * | 2009-01-28 | 2012-11-20 | Smith International, Inc. | Percussion hammer bit with a driver sub including a guide sleeve portion |
US9695647B2 (en) * | 2011-12-14 | 2017-07-04 | Varel International Ind., L.P. | Downhole tool retainer and guide ring |
US20130153208A1 (en) * | 2011-12-14 | 2013-06-20 | Ross Bassinger | Downhole Tool Retainer And Guide Ring And Methods Of Fabricating The Same |
US9291006B2 (en) * | 2011-12-14 | 2016-03-22 | Varel International Ind., L.P. | Downhole tool retainer and guide ring and methods of fabricating the same |
US20130319772A1 (en) * | 2012-06-01 | 2013-12-05 | Smith International, Inc. | Hammer bit locking mechanism |
WO2016122468A1 (en) * | 2015-01-28 | 2016-08-04 | Halliburton Energy Services, Inc. | Motor shaft transmission interference apparatus |
GB2547382A (en) * | 2015-01-28 | 2017-08-16 | Halliburton Energy Services Inc | Motor shaft transmission interference apparatus |
CN107109908A (en) * | 2015-01-28 | 2017-08-29 | 哈利伯顿能源服务公司 | Electric machine shaft driving countermeasure set |
US20170343046A1 (en) * | 2015-01-28 | 2017-11-30 | Halliburton Energy Services, Inc. | Motor shaft transmission interference apparatus |
RU2667366C1 (en) * | 2015-01-28 | 2018-09-19 | Халлибертон Энерджи Сервисез, Инк. | Safety device for the motor shaft transmission device |
GB2547382B (en) * | 2015-01-28 | 2019-05-29 | Halliburton Energy Services Inc | Motor shaft transmission interference apparatus |
US10605311B2 (en) | 2015-01-28 | 2020-03-31 | Halliburton Energy Service, Inc. | Motor shaft transmission interference apparatus |
US10760351B2 (en) | 2015-04-17 | 2020-09-01 | Halliburton Energy Services, Inc. | Coupling mechanism for driveshaft transmission assembly |
Similar Documents
Publication | Publication Date | Title |
---|---|---|
US7665548B2 (en) | Secondary retainer for a downhole hammer bit | |
US20080185187A1 (en) | Snap ringed bit retainer ring | |
US8701783B2 (en) | Apparatus for and method of deploying a centralizer installed on an expandable casing string | |
US8196670B2 (en) | Downhole device | |
US6793022B2 (en) | Spring wire composite corrosion resistant anchoring device | |
AU696213B2 (en) | A bit retention device for a bit and chuck assembly of a down-the-hole, percussive drill | |
US7025135B2 (en) | Thread integrity feature for expandable connections | |
US9520219B2 (en) | Retention member for perforating guns | |
US7077196B2 (en) | Expandable downhole tubular and method of use | |
US10895129B2 (en) | Open hole drilling magnet | |
US20080264629A1 (en) | Field-Assemblable Bow-Spring Casing Centralizer and Method of Making A Centralizer | |
EP0159764A2 (en) | A fastener for installing a sheet such as a lath spaced from a support | |
US20180163486A1 (en) | High-load collet shifting tool | |
US20210017834A1 (en) | Downhole plug assemblies with collet adapters and methods thereof | |
EP3879066B1 (en) | Slimline stop collar with solid cam ring | |
US20130319772A1 (en) | Hammer bit locking mechanism | |
US11421488B2 (en) | Mechanical locking system to eliminate movement between downhole components | |
EP3388616A1 (en) | Anchor system | |
RU59695U1 (en) | PROFILE OVERLAP | |
US20120306196A1 (en) | Anti-back off device for down hole tools and drive systems |
Legal Events
Date | Code | Title | Description |
---|---|---|---|
AS | Assignment |
Owner name: SMITH INTERNATIONAL, INC., TEXAS Free format text: ASSIGNMENT OF ASSIGNORS INTEREST;ASSIGNORS:SCOTT, JUSTIN;SWADI, SHANTANU;UNDERWOOD, LANCE D.;REEL/FRAME:023167/0575;SIGNING DATES FROM 20080311 TO 20080320 |
|
STCB | Information on status: application discontinuation |
Free format text: ABANDONED -- FAILURE TO RESPOND TO AN OFFICE ACTION |