Note : Les descriptions sont présentées dans la langue officielle dans laquelle elles ont été soumises.
- 21 93290
TITLE: PACKER WITH BACK-UP RETRIEVING METHOD
INVENTORS: WILLIAM D. HENDERSON and JEFFREY J. LEMBCKE
FIFT r~ OF THE INVFl~ION
The field of this invention relates to retrievable parlrPre, and more particu-
larly to packers that may be retrieved in more than one way.
10 BACKGROUND OF T~F T~VF~ITION
Packers are frequently used in oil and gas production to isolate one portion
of a wellbore from another. After being set in a wellbore for what could be as
long as many years, these p~rlr~rs need to be retrieved. Several ~ei~e have beenincorporated in the past for retrievable packers. One such packer, known as a seal-
15 bore-type packer, was run in on wireline. After setting the packer on wireline,
tubing was run and cf~nnecte~l to the packer by means of an anchor. In order to
retrieve this type of packer, the pro~lucfiQn tubing had to be ii.eco~n~cte~l from the
packer and removed from the wellbore. A sep~ale trip into the wellbore was then
required with a speci~lly designed retrieving tool that released the mech~nieme
20 within the packer to allow it to be unset and retrieved. Since the additional run of
tubing was made with hca~vyweight drillpipe with or without jars, which allowed
for tensile loads higher than the st~nd~rd production tubing, these types of packers
were often used and easily retrieved. Often these packers, after reln~ining in the
wellbore for many years, required the additional tensile loads that could be applied
25 through the heavy-wall tubing in combination with jars. These high-tensile loads
were l~ecess~.~ due to parts corroding together or debris settling out around the
packer. While this type of design allowed for retrieval, it was only at the expense
of running the heavy-wall tubing into the hole on a separate run. Typical of such
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packers are par~P-rs made by Baker Oil Tools under Product No. 646, also called
RETRIEVA-D; RETRIEVA-DB; and RETRIEVA-DAB LOCK-SET retrievable
packers.
Another type of packer previously used is referred to as a modified tubing-
set packer. This particular type of packer could be set on a wireline. Part of the
Pe,eembly of the packer included a seal nipple and an on/off tool. These compo-
nents were connP~ted to the packer mandrel above the packer and were left in thewell when the packer was set. The production tubing was then run in and eng~ged
with the on/off tool seal nipple. The packer was retrieved by manip~ ting the
tubing in combination with rotation and tension to release the packer. The packer
was then retrieved on the production tubing. While this technique was desirable
beca~ee it did not le~lui~c an additional tubing run, as indicated with the previously
descAbed seal-bore-type pac~Pre~ such pac~Pre have been found to be less reliable
when it comes to retAeval than the seal-bore pae~P-rs, pAmaAly due to the tensile
limits of the pro~uction tubing string, the on/off tool, and the packer mandrel.Typical of such ~es~Pmblies of the modified tubing-set packer are a wireline-setUni-Packer VI made by Guiber.eon ~VA, a division of Dresser Tn-lnstries. Nippleswhich convert perm~nPnt or retAevable pacl~Prs into t,lnpol~r bridge plugs and
which are carried in with the packer when it is set are known in the art and onesuch product is made by Baker Oil Tools, Model RS, Product No. 66548 Seffln~
Nipple.
Ac~ordiJlgly, an objective of the preselll invention is to provide a packer or
bridge plug which can be tubing-rele~ce~l but if such mode of release for any
reason does not function to release the packer or bridge plug, a back-up method
of release with a rele~eing tool is also available for the same packer. The alterna-
tive method of release functions akin to the operation of the seal-bore-type pac~e-rs
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and requires the ad~liti~m~l run into the wellbore with heavy-wall tubing to be
used. Accoldil~gly, the objective of the invention is to give a greater confi~len~
level to operators beyond that previously e~ri~on~ed with using only a modified
tubing-set packer. Now, with the plesent invention, if the modified tubing-set
packer with the production tubing string fails to release, an ~ltçnl~tive release
me~h~ m is available.
SUMMA~Y OF THF INVF~TION
A packer or bridge plug is described which may be released by manipulation
of the produr,tion tubing conr~ted to it. If manipulation of the production tubing
is rncllcc~s~irul in rele~cing the packer, the tensile strength of the production tubing
need not be excee~led in attempting to remove the packer. Tn~tead the productiontubing is removed along with certain intern~l compollents of the packer. Thereaf-
ter, heavy-wall tubing, with or without jars, can be lowered into the wellbore with
a retrieving tool at the bottom of that string. The lehiGvillg tool latches onto com-
poll~n~ of the packer to allow an ~ltçr l~tive method of release which allows for
use of significantly higher tensile loads to liberate the packer from the wellbore.
nFT~n~Fn nF~CRlPIlON OF TE~F n~WI~GS
Figures la-d illustrate the packer of the preselll invention in the run-in
position.
Figures 2a-d illu~hate the packer in the set position.
Figures 3a-d illu~h~te the packer in the set position with the washover shoe
of the on/off tool latched into a J-slot.
Figures 4a-d illustrate the fully retrieved position using the washover shoe
of the on/off tool latched into the l-slot.
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Figures 5a-d illustrate the tool in the set position after rotation off of the
lower end of the mandrel.
Figures 6a-d are similar to the view of Sa-d except showing the mandrel
sheared.
Figures 7a-d show the ~lt~Prn~tive retrieval using a retrieving tool.
nFT~l~ Fn nF~CRTPllON OF T~F pRFFFRRFn Fl~RODIl~IF~T
Referring to Figures la-d, the app&,alus of the lJles~nt invention is illus-
trated. Since many of the fealules of the packer are st~n~l~rd collll~onents, they will
10 be described only very briefly. Packers or bridge plugs generally have a series of
slips 10 and se~ling elements 12. The slips 10 anchor the packer, while the sc~ling
elements 12 seal off around the periphery. The slips 10 are cammed outwardly
along ta~red s~ ec 14, while the s~P~ling elements 12 e~p~n~l radially oulw~dly
by beco.lling comp.essed between rings 16 and 18. Ring 18 is connectP~ to a set-
15 ting sleeve 20. A setting tool S of the type well-known in the art has components
that move in opposile directions to create the nec~P-ss~ relat*e movement to urge
the slips 10 along the tapered snrf~c~e 14, followed by the setting of the sealing
elemP-nte 12 as rings 16 and 18 approach each other.- A lock ring 22 holds the set
of the e~ling elements 12 after co.llples~ion has oc~ulled, as seen by co.~-p~ g20 Figure lc to Figure 2c. The setting tool S has a du~lw~dly moving sleeve 24,
which bears on setting sleeve 20 but is otherwise not physically connect~P~ thereto.
Another pOniOn of the setting tool S includes a sleeve 26 which is secured to a
mandrel 28 by a shear pin 30. Sup~lled by mandrel 28 is a known b1~nlcing plug
32 which is run in with the entire ~sembly so as to seal off an internal bore 34 in
25 the packer, using seal 36.
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Not shown in the drawings is the wireline ~uppoll for the setting tool S
which allows the proper positioning of the packer in the wellbore. The setting tool
S is ~stn~t~P~ in known ways to create dirr~.enlial movement between sleeves 24
and 26 such that sleeve 24 moves dow-l~dly, while sleeve 26 moves u~v~dly
5 to ac~omplish the setting~ as indicated by the arrows in Figure 2a. This dilr~ nlial
movement cams the slips 10 oulw~-dly~ as shown in Figure 2c. C~ntinl~P~ differ-
ential movement brings rings 16 and 18 closer together, while the lock ring 22,
using r~trheting teeth 23, retains the position of all the components, as shown in
Figure 2c. Shear pin 30 is sheared after full setting force is applied. This allows
10 the setting tool S to be removed. At this point, the setting tool S can be removed
and the pro-luction tubing run in the hole, coupled with a washover shoe 38 (seeFigure 3a). The washover shoe 38 has a J-slot arrangement 40 which latches onto
lug 42, which is part of the mandrel ~c.cernbly 28. It can also be secured by other
means. Seals 44 effectively seal between the washover shoe 38 and the mandrel
15 28. Once that task is ac~omplished, the bl~nking plug 32 is removed by wireline.
It should be noted that the production tubing 46 :iUppOlk~ the washover shoe
38 until the J-slot 40 c~tchP~ the lug 42. At that time, the production tubing string
46 is sP~lin~ly engaged to the mandrel 28 and, upon removal of the bl~nking plug32, production through the packer P can commPnce in a known ...~ -r.
When it comes time to release the packer, Figures 4a-d illu~llale one tech-
nique. In this technique, a rotational forc~ is applied to the production tubing 46.
This rotation undoes thread 48, which is shown in Figure 4b already s~ aled.
With thread 48 un~1onP., an u~v~d force is applied on the producti~ tubing 46,
brin~ing up mandrel 28. Packer mandrel 29 is ret~inP~l in a fi~ed position due to
m~ting teeth 72 and 74. At its lower end 52, mandrel segment or sleeve 28 has a
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lug 54 which is secured to sleeve 50 by shear pin 56. Below lug 54 is ring 58,
which is c~m~-cte~l to sleeve 28 at thread 60.
As shown in Figure 3d, the set position of the slips 10 and se~ling elements
12 is also lel~ ~l by collet fingers 70, which have teeth 72 which engage teeth 74
S on bottom sub 76. The position of the fingers 70 is secured by a ring 78 which is
secured to the fingers 70 by a shear pin 80. Those skilled in the art will a~ple~;iate
that a multiplicity of fingers 70, each with teeth 72, are employed, all of which
engage the teeth 74 on the bottom sub 76.
Referring now to Figure 4d, it can be seen that after the thread 48 is undone
and an u~w~J pull is applied to the tubing string 46, lug 54 bears on ring 78 toultimately break shear pin 80. When shear pin 80 breaks, the ring 78 can move
u~w~dly, thus allowing the fingers 70 to flex radially inwardly so as to allow the
teeth 72 to sep~ate from the teeth 74. When this occurs, the ~esemhly that holdsthe slips 10 and the se~ling ele.m~-nt 12 in a co.,-~leseed state can be e~tPn~le~l by
15 c~ g the u~,w~d pull on the production string 46.
Ultimately, as shown in Figure 4c, the slips 10 ride down the tapered s~R~e
14 and are retracted. A co~ u~w~ pull on the production string 46 will
move ring 18 away from ring 16 to allow the sealing elements 12 to relax to the
poeitinln shown in Figure lc. As shown in Figure 4c, the fingers 70 have had their
20 teeth 72 move completely away from the interengAging teeth 74 as a result of the
breaking of shear pin 80. Lug 54 then ~uppolls ring 78 when there is further
u~w~d pulling on the production string 46. Ring 78 is shaped so that it cannot fall
off of fingers 70, even after shear pin 80 is broken bec~se it c~tclle~e shoulder 81.
With lug 54 in contact with ring 78, the entire weight of the packer shifts to the
25 production string 46 and it can then be removed, ~ .n~ g that no complications
develop.
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However, esreci~lly for paCL-~re that have been in the wellbore for many
years, the motions previously described may not be sufficient to release the packer
from the wellbore. Thus, despite the undoing of thread 48 and the exertion of anu~d force within the limits of the tensile loads which can be applied through
S the production tubing 46, the assembly for a multiplicity of reasons just fails to
give way to allow the slips 10 or the se~ling elements 12 to relax.
If this should occur, the appalalus of the plesent invention has a backup
method of removal of the packer, which is illustrated in Figures Sa-d through 7a-
d.
Figure Sb shows thread 48 ntlon~ after rotation of the washover shoe 38,
as previously described. Now, since the packer will not release, further rotation
occurs from the position shown in Figure 4d. The lug 54 can be released with
respect to the sleeve 28 by breaking the shear pin 56 if it has not already beenbroken. The tubing string 46 is then rotated to undo thread 60. This leaves ring58, as well as lug 54, resting on shoulder 82, as shown in Figure Sd. With thread
60 now sep~aled as shown in Figure Sd, the pro~ ction tubing 46 can be pulled
out of the hole, taking with it the ~e~mbly co~n~ g the washover shoe 38 as
well as the sleeve 28.
This having been accomplished, heavy-wall tubing 83, with or without jars,
can be made up at the surface and run into the hole on top of a known release tool
R, as illu~ ted in Figures 7b-c. At this point in time, the ring 78 is eng~ged by
the release tool R, as shown in Figure 7c. Now, with the heavy-wall tubing 83 inplace and jars, if desired, in place, further efforts applying an even greater force
can be made to release the packer and retrieve it from the wellbore.
Figures 6a-d illu~ te yet another way of removing sleeve 28 from the
wellbore so as to expose the ring 78 for ultimate engagement with the release tool
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R In Figure 6c-d, the sleeve 28 actually shears in two pieces, leaving behind a
piece 28' resting on shoulder 82. The sleeve 28 is ~1P-S;~P~ to have a weak
section 84 which, prior to deliberate failure, is cor~necte~ to weak section 84' such
that upon an u~,w~rd force on the production tubing 46, a break occurs between
S ~g~ L~i 84 and 84', as shown in Figure 6d. In this ~ltern~tive de-~i~, shear pin
56 breaks first and the connection between weak sections 84 and 84' fails after the
shear pin breaks, with the result that the segment 28' merely falls dowll~dly
until it is caught by shoulder 82. Even in this embodiment, ring 52 can still berotated off before she~rin~ 84 from 84'.
Regardless of which technique is used as between the twist-off technique
shown in Figure Sd or the shear technique in Figure 6d, the final step is to run in
the hole with the retrieving tool R, which has a series of collets 86 supported by
a body 88. The collets 86 are spring-loaded using a spring or springs 90. The
collets 86 are deflected ~gain~t the spring 90 and flex toward the body 88 to get
lS past the ring 78. After pPC~ing the ring 78, the assembly is picked up and the
collets 86 are trapped ~gainct body 88 as shown in Figure 7c. Upward pulling on
the heavy-wall tubing or use of the jar combined with u~d pulling ultimately
results in the retrieval of the packer.
Those skilled in the art can readily see that a packer design has been pro-
20 vided which allows for release with the production tubing without an extra trip into
the wellbore. Hu..~ ~, if the release t~ht~ ue using the production tubing 46
proves ineffective to liberate the packer from the wellbore, a bafflp release
technique is provided. The production tubing 46 must be removed from the
wellbore. Ho~ , such removal effectively takes with it sufficient components
25 so as to expose the lug or ring 78 so that on a second trip with heavy-wall tubing
and/or jar eq~ ment~ the lug 78 can be .~c~s.ce~ for even greater applied forces
2 1 93290
than could be applied using the production tubing 46. While a second trip into the
wellbore is required if the production tubing 46 does not dislodge the.packer,
o~r~to.~ can have greater confidenr~ in the removability of their parl~P-r~ by
knowing that a backup terhnique for removal of the packer exists. Thus, e~peneive
S and time-co ~Q- ming mi11in~ operations can be avoided since the backup technique
allows the application of subst~nti~lly greater extraction forces than could be
applied using the production tubing 46.
The foregoing disclosure and description of the invention are illustrative and
explanatory thereof, and various c~l~nges in the size, shape and materials, as well
10 as in the details of the ill~ ted con~lluction, may be made without d~alling
from the spirit of the invention.
