U.S. patent number 3,697,113 [Application Number 05/127,988] was granted by the patent office on 1972-10-10 for drill rod retrieving tool.
This patent grant is currently assigned to Gardner-Denver Company. Invention is credited to James R. Mayer, Dieter K. Palauro.
United States Patent |
3,697,113 |
Palauro , et al. |
October 10, 1972 |
DRILL ROD RETRIEVING TOOL
Abstract
A tool for retrieving tubular drill rods or the like from a
drill hole. The tool includes an elongated cylindrical member which
is dimensioned to be insertable into the broken or disconnected
drill rod to be retrieved. The elongated member includes a
frictional coupling made up of a plurality of elastically
deformable gripping rings which are retained in sleeved
relationship on the elongated member. The retrieving tool also
includes a drill rod engaging member having a skirt defining a
conical surface which surrounds and wedgingly engages the broken
end of the drill rod. The drill rod engaging member is threadedly
connected to the elongated cylindrical member. In response to
rotation of the retrieving tool the two members move axially with
respect to each other to compress the stack of deformable rings
into frictional engagement with the broken drill rod whereby the
broken drill rod may be retrieved from the drill hole. In an
alternate embodiment the elongated cylindrical member is formed in
two sections threadedly connected and thereby being axially movable
with respect to each other for compressing the deformable gripping
rings.
Inventors: |
Palauro; Dieter K. (Denver,
CO), Mayer; James R. (Dallas, TX) |
Assignee: |
Gardner-Denver Company (Quincy,
IL)
|
Family
ID: |
22433022 |
Appl.
No.: |
05/127,988 |
Filed: |
March 25, 1971 |
Current U.S.
Class: |
294/86.24;
294/86.12; 294/86.22 |
Current CPC
Class: |
E21B
31/20 (20130101) |
Current International
Class: |
E21B
31/20 (20060101); E21B 31/00 (20060101); E21b
031/02 () |
Field of
Search: |
;294/86.1,86.12,86.24,86.25,86.32,86.22
;166/99,118,138,139,206,210,216,217 |
References Cited
[Referenced By]
U.S. Patent Documents
Primary Examiner: Blunk; Evon C.
Assistant Examiner: Cherry; Johnny D.
Claims
What is claimed is:
1. A tool for retrieving an elongated hollow drill rod or the like
comprising:
an elongated member adapted to be coupled to a rotatable drill
string and inserted into the interior of a hollow drill rod to be
retrieved;
frictional coupling means including elastically deformable means
operable to be elastically deformed into frictional gripping
engagement with an interior wall of said hollow drill rod; and,
a drill rod engaging member including a portion adapted to surround
and wedgingly engage an end portion of said hollow drill rod
nonrotatably relative thereto, said drill rod engaging member being
cooperable with said elongated member to engage and elastically
deform said frictional coupling means.
2. The invention set forth in claim 1 wherein:
said elongated member is responsive to the rotation of said drill
string to be cooperable with said drill rod engaging member to
elastically deform said frictional coupling means.
3. The invention set forth in claim 1 wherein:
said elastically deformable means comprises a plurality of ringlike
members mounted in stacked relationship on said elongated member,
said stack of ringlike members being engageable at one end thereof
by said drill rod engaging member and in response to the rotation
of said drill string said elongated member is operable to move
axially with respect to said drill rod engaging member to
elastically deform said ringlike members into frictional gripping
engagement with said interior wall of said drill rod for coupling
said drill rod to said tool to remove said drill rod from a drill
hole.
4. The invention set forth in claim 3 wherein:
said elongated member includes a threaded portion and said drill
rod engaging member includes a complementary threaded portion
engaged with said threaded portion on said elongated member and in
response to the rotation of said drill string said elongated member
is operable to rotate and thereby move axially with respect to said
drill rod engaging member.
5. The invention set forth in claim 4 wherein:
said tool includes a rotatable member coupled directly to said
drill string and interposed between said elongated member and said
drill string, said rotatable member and said elongated member are
threadedly engaged with each other and said elongated member is
operable to move axially with respect to said rotatable member to
elastically deform said ringlike members in response to the
rotation of said rotatable member.
6. The invention set forth in claim 5 wherein:
said elongated member is engaged with said drill rod engaging
member for nonrotatable but axial movement relative thereto in
response to the rotation of said rotatable member.
7. The invention set forth in claim 6 wherein:
said frictional coupling means comprises a plurality of
substantially rigid force transmitting members alternately spaced
between said ringlike members and operable in response to the axial
movement of said elongated member to elastically deform said
ringlike members substantially radially outwardly with respect to
the longitudinal axis of said tool.
8. The invention set forth in claim 7 wherein:
said ringlike members are elastically deformable in a radial and
axial direction.
9. The invention set forth in claim 7 wherein:
said portion of said drill rod engaging member comprises a skirt
defining a conical surface.
Description
BACKGROUND OF THE INVENTION
In drilling wells, blast holes, and the like the retrieval of
broken or disconnected sections of drill rod is often necessary.
The cost of lost rod sections and drill bits as well as the
necessity of redrilling the hole if broken sections cannot be
retrieved is usually prohibitive. Accordingly there has developed
in the art of drilling apparatus means for retrieving broken or
disconnected sections of drill rod or pipe from the drill hole.
Fishing tools or drill pipe retrieving tools are known which are
operable to be inserted in the open end of a tubular drill rod or
oil well casing and which include movable members for gripping the
inner wall of rod or pipe section to be removed. However, most
known devices in the art of retrieving tools are somewhat
complicated mechanically and include types which are primarily
useful in disconnecting one section of rod or casing from another
for removing only part of the extension pipe string located in the
drill hole.
SUMMARY OF THE INVENTION
The present invention provides for a retrieving tool for tubular
drill rod or the like whereby broken or disconnected portions of an
extension drill string may be removed from a drill hole. The
retrieving tool of the present invention may be used with the
extension drill string members and the drilling equipment used to
drill the hole thereby alleviating the need for any additional
specialized equipment to be brought into use for retrieving the
broken or disconnected drill rod sections.
The present invention further provides for a drill rod retrieving
tool which is adapted to be removably connected to the lower end of
an extension drill rod for lowering into a drill hole to engage and
retrieve a broken or disconnected drill string. The drill rod
retrieving tool of the present invention also includes means for
positively engaging the broken end of the drill rod section to be
retrieved whereby the retrieving tool may then be actuated to
frictionally grip the inner wall of a tubular drill rod section
sufficiently to enable retrieval of the drill string portion lodged
in the drill hole.
Furthermore the present invention provides for a retrieving tool
for tubular drill rod or the like which is simple in construction
and reliable in operation.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a longitudinal section view of the drill rod retrieving
tool of the present invention.
FIG. 2 is a transverse section view taken along line 2--2 of FIG.
1.
FIG. 3 is a partial longitudinal section of an alternate embodiment
of the present invention.
FIG. 4 is a partial longitudinal section of yet another embodiment
of the present invention.
FIG. 5 is a perspective view of one of the radially expandable
gripping rings of the embodiment of FIG. 4.
FIG. 6 is a longitudinal section view of a third alternate
embodiment of a retrieving tool according to the present
invention.
FIG. 7 is a section taken along the line 7--7 of FIG. 6.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
Referring to FIG. 1 of the drawing a drill rod retrieving tool
according to the present invention is illustrated in longitudinal
section and generally designated by the numeral 10. The retrieving
tool 10 includes an elongated member 12 having an internally
threaded portion 14 at one end adapted to be threadedly coupled to
the lower end of an extension drill rod section 16. The drill rod
section 16 is in turn connected to an extension drill string which
is adapted, in a well known manner, to be rotatably and
longitudinally driven by drilling apparatus, not shown. The member
12 also includes an externally threaded portion 18 at the opposite
end thereof. Intermediate the threaded portions 14 and 18 is an
elongated portion 20 having a cylindrical cross section and a third
threaded portion 22 having external threads but of an opposite hand
to the threaded portions 14 and 18 the latter two portions being of
the same thread hand.
Threaded over the lower end of the member 12 is a cap 24. The cap
has a tapered portion 26 to facilitate insertion of the retrieving
tool 10 into the broken or otherwise open end of a hollow drill rod
or pipe section such as the tubular drill rod 28 shown in FIG. 1.
Longitudinal passageways 30 and 32, centrally located in the member
12 and cap 24, respectively, are operable to conduct drill hole
cleansing fluid therethrough.
The retrieving tool 10 includes frictional coupling means generally
designated by the numeral 34 for coupling the tool to a drill rod
or pipe section or like member having a substantially tubular
configuration and an opening into which the retrieving tool can be
inserted in close fitting relationship. The frictional coupling
means comprises a plurality of elastically deformable ringlike
members 36 retained in sleeved relationship over the cylindrical
portion 20 of the member 12. Interposed between the elastically
deformable members in alternating relationship are ringlike members
38. The elastically deformable members 36 are formed to have sides
40 which slope radially inwardly from their outer diameters 42 to
the inner diameters 44. This configuration provides for a greater
surface area on the outer diameter 44 for contacting the inner wall
46 of the tubular rod 28 than the surface area of the inner
diameters 44, which in the deformed condition of the members 36
grip the cylindrical portion 20. The elastically deformable members
36 are dimensioned so that in the nondeformed condition the inner
diameter 44 is in close fitting but relatively movable relationship
to the cylindrical portion 20 of the member 12. The ringlike
members 38 have radially sloping sides complementary to the sides
of the elastically deformable gripping members 36. The gripping
members 36 may be formed of an elastically deformable material such
as molded polyurethane or the like. The ringlike members 38 are
primarily force transmitting members and are more suitably made of
a substantially hard material by comparison, such as steel or other
metal material.
The retrieving tool 10 also includes means adapted to be
nonrotatably engageable with the end 48 of the broken drill rod 28
comprising a member 50 having a skirt 52 defining a conical sloped
inner surface 54. The member 50 further comprises a nut having
threads engageable with the third threaded portion 22 on the member
12. The nut 50 also includes an integral tubular portion 56
extending in sleeved relationship over the cylindrical portion 20
of the member 12 and engaged with the stack of gripping members
forming the frictional coupling 34. As shown in FIG. 1 the sloped
surface 54 is engageable with the broken or open end 48 of the
tubular drill rod 28 and with sufficient axial force applied, a
wedging action is obtained which results in nonrotatable engagement
of the nut 50 with respect to the drill rod 28. The surface 54 may
be knurled or provided with threads or ridges to further enhance
positive engagement of the drill rod 28. A resilient washer 58 is
interposed between the nut 50 and the shoulder 60 on the member 12
to aid in preventing the nut from becoming excessively tight
against the shoulder should the nut be advanced thereagainst. As
shown in FIG. 2 the nut 50 also includes transverse surfaces or
flats 62 for engagement with a suitable holding fixture or wrench,
not shown.
The retrieving tool 10 is operable to be frictionally coupled to
the drill rod 28 to remove the same and additional drill rod
extension members connected thereto from the drill hole 64, FIG. 1.
Upon being threadedly connected to the drill rod 16, the retrieving
tool 10 is lowered into the drill hole 64 whereupon the tapered
portion 26 of the cap 24 upon engagement with the broken end 48
serves to guide the retrieving tool into the tubular rod 28. The
tool is lowered until the skirt 52 forcibly engages the broken end
48. Normal pull-down force exerted by the drilling apparatus, not
shown, to which the drill rod 16 is attached will result in a
substantial wedging action of the end of the tubular rod 28 against
the surface 54 of the skirt 52 to provide nonrotatable engagement
of the nut 50 with respect to the drill rod 28. While maintaining
suitable pull down or downward axial force on the drill rod 16 the
drilling apparatus is operated to rotate the drill rod and
retrieving tool attached thereto in a direction tending to tighten
the threaded connection 14. The third threaded portion 22 on the
member 12 being of the opposite hand will result in the member 12
tending to move axially with respect to the longitudinal axis 53 of
the retrieving tool upward out of the tubular drill rod 28 while
the nut 50 remains positively and nonrotatably engaged with the
drill rod 28. Normally, the broken drill rod 28 will not tend to
rotate due to friction of the remainder of the extension drill
string, not shown, therebelow against the side if the drill hole,
and due also to the drill bit, not shown, being forcibly engaged
with the bottom of the drill hole. The axial movement of the member
12 with respect to the nut 50 will result in compression of the
elastically deformable members 36 whereby they will become
elastically deformed radially outwardly into frictional gripping
contact with the inner wall 46 of the tubular drill rod 28. The
members 36 also tend to deform radially inwardly against the
cylindrical portion 20 and frictional rubbing occurs. However, the
contact area of the inner diameters 44 being less than that of the
outer diameters 42 of the gripping members 36 will result in the
gripping members tending to remain nonrotatable, although they will
undergo some axial movement as the stack is compressed.
When a predetermined amount of resistance to rotation of the drill
rod 16, which has been predetermined to be commensurate with
suitable gripping of the broken drill rod, is percieved by the
drilling apparatus operator the retrieving tool 10 and the broken
drill rod frictionally coupled thereto are raised out of the hole
64. When the tool 10 and a sufficient portion of the drill rod 28
are out of the hole suitable holding means may be applied to the
flats 62 and the drill rod 16 is then rotated in the opposite
direction to relieve the axial force on the stack of elastically
deformable gripping members. With the axial compressive force on
the gripping members 36 released, said members will again assume
their undeformed shape as shown in FIG. 1 whereupon the retrieving
tool 10 may be removed from the tubular drill rod 28.
An alternate embodiment of the frictional coupling means is shown
in FIG. 3 and designated by the numeral 70. In the embodiment of
FIG. 3 the frictional coupling 70 comprises a plurality of pairs of
elastically deformable ringlike members 72 and 74 having
complementary sloped surfaces 76 and 78, respectively. The pairs of
deformable members 72 and 74 are spaced apart by rigid force
transmitting members 80 in substantially the same arrangement as
shown in FIG. 1. The stack of members 72 and 74 are retained on the
cylindrical portion 20 of member 12 by a cap 82 similar to the cap
24 in the embodiment of FIG. 1 and at the opposite end are engaged
by the sleeve portion 84 of a nut substantially the same as the nut
50.
In response to the operation of the retrieving tool to compress the
deformable members 72 and 74, the axial force applied to the stack
of deformable members will act across the interface formed by the
surfaces 76 and 78 and will cause the members 72 and members 74,
respectively, to deform radially inwardly and radially outwardly.
The members 74 will be deformed into frictional gripping
relationship with the wall 46 of the tubular drill rod 28. There
will be some relative slippage between the members 72 and 74 in
both the axial direction and rotationally as the member 12 is
rotated to compress the deformable members. The embodiment of FIG.
3 provides for more effective deformation of the members 74 into
frictional gripping engagement with the tubular drill rod 28. The
members 72 and 74 are suitably made of an elastically deformable
material such as polyurethane or the like as in the embodiment of
FIG. 1.
In FIGS. 4 and 5 another embodiment of the frictional coupling
means of the retrieving tool of FIG. 1 is illustrated. In the
embodiment of FIGS. 4 and 5 the frictional coupling 86 comprises a
plurality of elastically deformable ringlike members 88 alternately
spaced between substantially nondeformable force transmitting
members 90 which are slidable on the cylindrical portion 20 of the
member 12. The members 88 are defined by an outer cylindrical
surface 92 and by the conical surfaces 94 and 96 sloping axially in
opposite directions. The members 90 are provided with surface
portions 98 and 100 engageable with the surfaces 96 and 94,
respectively, on the members 88. A member similar to the nut 50 of
FIG. 1 has a sleeve portion 102 modified to engage the endmost
member 88. The opposite end of the frictional coupling 86 is
retained on the cylindrical portion of the member 12 by a cap 104
similar to the cap 24 of FIG. 1. A member 108 having a sloping
surface complementary to the conical surface of the endmost member
88 is provided for transmitting axial force to the stack of members
88 and 90. The member 108 also provides a bearing surface 110 for
permitting relative rotation between the cap 104 and the frictional
coupling arrangement of FIG. 4.
As shown in FIG. 5 the elastically deformable gripping members 88
include a radial slot 112 formed therethrough. Moreover, the
members 88 are preferably made of spring steel although nonmetallic
elastic materials may also be used.
The operation of the frictional coupling means of the embodiment of
FIG. 4 is substantially the same as the embodiments of FIGS. 1
through 3. However, in the embodiment of FIG. 4 the axial force
imposed on the frictional coupling 86 tends to close the spaces 99
between the members 90 resulting in a force component acting across
the interface of surfaces 94 and 100, and 96 and 98 which expands
the members 88 radially outwardly into gripping relationship with
the wall 46 of the tubular drill rod 28. Moreover, if the members
88 are made of spring steel, as preferred, the elastic deformation
is not one of substantial plastic flow in the sense of the
deformation of the members 36 of FIG. 1 or the members 72 and 74 of
FIG. .3. Furthermore, the members 88 do not come into forcible
contact with the cylindrical portion 20 of the member 12 and hence
no frictional rubbing occurs therebetween during the operation of
the tool to actuate the frictional coupling 86. In fact, an
advantage of the embodiment of FIG. 4 is that substantially reduced
frictional rubbing occurs during the actuation of the members 88 to
grip the wall of the drill rod 28. The members 88 and 90 tend only
to move axially and substantial relative sliding normally occurs
only between the member 108 and the cap 104. Therefore, the
rotational effort required to turn the member 12 is more
efficiently converted into frictional gripping of the drill rod 28.
In the relaxed or nonactuated condition the members 88 and 90 of
the frictional coupling of the embodiment FIG. 4 are in the
position shown, the members 90 being spaced apart by the radial
inward spring bias of the members 88.
FIGS. 6 and 7 illustrate an alternate embodiment of a drill rod
retrieving tool in accordance with the present invention and
generally designated by the numeral 120. The retrieving tool 120
includes a member 222 adapted to be threadedly connected to the
lower end of the drill rod 16 in the same manner as the member 12
of the retrieving tool 10. The member 122 also includes a
transverse shoulder 124 formed between the threaded portion 126 and
a reduced diameter portion 128. The reduced diameter portion 128
has an internal bore 130 including a threaded portion 132.
Threadedly engaged with the member 122 is an elongated member 134
having a tapered nose 136 forming a transverse shoulder 138 and an
elongated cylindrical portion 140 having longitudinal splines 142
formed thereon. The member 134 is retained in assembly with the
member 122 by a retaining ring 146.
The retrieving tool 120 also includes a frictional coupling 148 for
engaging the inner wall 46 of the broken drill rod 28. The
frictional coupling of the retrieving tool 120 includes a plurality
of elastically deformable gripping members 150 mounted in sleeved
relationship on the splined portion 140 of the member 134. The
gripping members 150 are alternately spaced between substantially
rigid force transmitting ring members 152 which are splined to the
portion 140 of the member 134. A spacer 154 is mounted on the
portion 140 against the shoulder 138. The gripping members 150 may
be suitably made of molded polyurethane and are provided with a
radial slot in the same manner as the members 88 to facilitate
assembling them on the retrieving tool of FIG. 6.
The retrieving tool 120 further includes means adapted to be
nonrotatably engaged with the broken drill rod 28 comprising a
sleevelike member 156 having a skirt 158 defining the sloped inner
surface 160. The surface 160 is operable to surround and be
wedgingly engaged with the end 48 of the broken drill rod. The
member 156 includes an integral tubular portion 162 extending in
sleeved relationship around the cylindrical splined portion 140.
The member 156 further includes internal splines 164 extending part
way into the bore 165 and engaged with the splines 142 on the
member 134 whereby the member 156 is axially movable but
nonrotatable with respect to the member 134. The distal end of the
tubular portion 162 engages the endmost gripping member 150. The
opposite end of the member 156 includes a bearing surface 166
engaged with the shoulder 124 on the member 122. The elongated
member 134 also includes a longitudinal cleansing fluid passage 168
through which drill hole cleaning fluid may be pumped during
operation of the retrieving tool to clear debris from within the
tubular drill rod 28 and to facilitate removal of the broken drill
rod and portion of the extension drill string remaining in the
drill hole.
The operation of the retrieving tool 120 is carried out in a manner
similar to that of the retrieving tool 10. The tool 120 is inserted
into the open end of the broken drill rod 28 until the surface 160
on the member 156 is forcibly engaged with the end 48 of the broken
rod. As in the tool 10 the surface 160 may be knurled or threaded
to improve the wedging and gripping action of the member 156 with
respect to the drill rod. With the member 156 nonrotatably engaged
with the drill rod 28 the drill rod 16 is rotated to tend to
tighten the threaded connection with the member 122 and thereby
rotate the member 122. The threads 126 and 132 being of the same
hand will result in the movement of the elongated member 134
axially to compress the stack of elastically deformable gripping
members 150 forcing same to deform radially outwardly into
frictional gripping engagement with the inner wall of the drill rod
28. Relative sliding occurs on the bearing surface 166 as the
member 122 rotates with respect to the members 134 and 156. The
reduced diameter portion 128 is also rotatably journaled in the
bore 165. As in the operation of the tool 10 any tendency for the
broken drill rod 28 and the remainder of the drill string connected
thereto to rotate can be countered by increasing the axial or
pull-down force on the retrieving tool and the drill string portion
left in the drill hole.
Upon retrieving the broken or disconnected drill string from the
drill hole, the retrieving tool 120 may be disconnected from the
drill rod 28 by holding the member 156 stationary and rotating the
drill rod 16 and member 122 connected thereto in the reverse
direction. With the retrieving tool 120 there is also scant loss of
energy due to friction in the conversion of turning effort of the
drill rod 16 into gripping action of the coupling 148 with the
drill rod 28. As previously mentioned, relative sliding of engaged
members takes place across the bearing surface 166 and 124 which
can be suitably prepared with coatings of low friction material and
lubricant. The frictional resistance to turning of the threaded
connection between the members 122 and 134 can also be minimized
with accurately formed threads and suitable lubrication before
use.
* * * * *