Note: Descriptions are shown in the official language in which they were submitted.
CA 02452125 2003-12-31
TITLE: METHOD AND APPARATUS FOR POSITIONING
AND REPOSITIONING A PLURALITY OF SERVICE
TOOLS DOWNHOLE WITHOUT ROTATION
INVENTOR(S): DAVID A. HENLEY and MICHAEL E. McMAHAN
FIELD OF THE INVENTION
The field of this invention relates to methods and equipment to allow
running of a plurality of service tools downhole together and to deploy them
where desired and redeploy them in the well, all preferably without rotation
of
at least one of the tools from the surface.
BACKGROUND OF THE INVENTION
As techniques have become more sophisticated for locating subterra-
nean reservoirs, welibores have become more deviated in an effort to extract
the hydrocarbons from below the surface. Coiled tubing has become more
prevalent in running tools downhole. Even 'rf rigid tubing is used in a
deviated
wellbore, actuation of downhole tools using rotation becomes difficuft. With
the downhole tools supported on coiled tubing, rotation is not possible as
part
of a technique to set or release downhole tools.
Many reservoir treatment procedures require isolation of a specific zone
in the weilbore and the application of fluids to the formation in the isolated
zone. In order to accomplish this, the zone is generally isolated between a
bridge plug located below and a service packer above. A work string is
connected to the service packer for access between the two isolation devices
so that, for example, the formation can be acidized between the bridge plug
and the service packer above. In many situations, the process must be
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repeated at multiple locations. One technique that has been used in the past
where multiple locations need to be isolated is that the lowermost location
has
an expendable.bridge plug set below it and the service packer is run on a
work string to define the first zone to be treated. When the next zone needs
to be treated, the service packer is removed from the welibore and another
expendable bridge plug is inserted to define the lower portion of the next
zone
to be isolated. The service packer is then run in the hole again and the next
zone is isolated. This process is repeated until all zones to be treated have
been isolated in a similar fashion. At the conclusion of the treatment or
procedure, the service packer is removed and all the bridge plugs which have
been placed in the wellbore are milled out. There are distinct disadvantages
in this procedure in that it requires multiple trips in and out of the well
with the
service packer so that subsequent bridge plugs can be deployed. Each of the
bridge plugs must be separately run in the well and ultimately milled out.
Thus, improvements to this technique have generally involved reducing the
mill-out time for all the bridge plugs that are in the wellbore. One way this
has been accomplished is to make the bridge plugs of generally soft, nonme-
tallic components so that they can be drilled quickly. Typical of such plugs
which are designed to be easily drilled out are U.S. Patents 5,224,540 and
5,271,468 issued to Halliburton.
Another way to accomplish the goal of servicing discrete portions of a
welibore in one trip is to use a straddle tool which has a pair of packers
which
can be set and unset as desired. One of the disadvantages of this type of a
tool is that the distance between the packing elements on the tool is defined
at the surface when the bottomhole assembly is put together. These tools,
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typically referred to as "wash tools," are illustrated in U.S. patents
4,815,538;
4,279,306; 4,794,989; 5,267,617; 4,962,815; 4,569, 396; and 5,456,322.
Another method of isolating and treating zones is accomplished by
running a retrievable bridge plug below a service packer. The coupled system
is run just below the zone of interest, the bridge plug is set and uncoupled
from the service marker. The service packer is then moved up the hole just
above the zone and set by rotation and weight to complete the zone isolation.
When treatment is complete, the service packer is unset, moved downhole to
recouple with the bridge plUg, then unset and moved up the hole to repeat the
operation.
Service packers and bridge plug systems that individually set with
rotation and setdown force are known. These packer/bridge plug combina-
tions have been used in the procedure described above involving one trip to
accomplish straddles of different zones. Typical of such packers are the
Retrievamatic and model G retrievable bridge plug offered by Baker Oil
Tools and the RTTS service packer and 3L bridge plug offered by Halliburton.
Tension-set packers, involving a rotation and pickup force, are also known.
Typical of these are the Baker Oil Tools Model C "Full Bore" service packer
. and the Model C cup-type bridge plug.
What is desirable and is an object of the present invention is to provide
an apparatus and method to allow isolation of zones of various lengths in a
wellbore by allowing deployment of isolation devices where desired where the
isolation devices are actuated without rotation. Another objective of the
present invention is to allow redeployment of the isolation devices in
different
locations in the welibore without a trip out of the well. More particularly,
where
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rotation is not possible, the objective is to allow for the deployment and
rede-
ployment and separation downhole between the isolation devices, using fluid
pressure and/or longitudinal movements only. Yet another objective of the
present, when used with a bridge plug and a service packer, is to keep the
service packer locked against setting while the bridge plug is being set.
Thereafter, when the service packer is separated from the set bridge plug, the
act of separation unlocks the service packer, allowing it to be subsequently
set on further manipulations when it reaches its desired location in the well-
bore. Yet another objective is to allow the bottomhole assembly to be open
to circulation during run-in and closed off when the bridge plug is set. The
bridge plug can be equalized by reopening a passage therethrough prior to
release of the bridge plug. These and other objectives of the present inven-
tion will be more apparent to those of skill in the art from a review of the
preferred embodiment described below.
SUMMARY OF THE INVENTION'
A method and apparatus is disclosed for downhole remediation. In the
preferred embodiment, a bridge plug and service packer can be run into a well
on coiled or rigid tubing. The assembly is capable of being set without rota-
tion. The service packer is locked against setting untii it is separated from
the
bridge plug. Setting of the bridge plug closes a passage within it that had
been open to facilitate circulation during run-in. The service packer is set
with longitudinal movements using an indexing mechanism. At the conclusion
of the procedure, the service packer is released and lowered to recapture the
bridge plug. The bridge plug is equalized and released to allow the assembly
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to be repositioned elsewhere in the wellbore or retrieved. The spacing
between the packer and bridge plug can be varied as desired.
Accordingly, in one aspect of the present invention there is provided a
method of setting a sealing device downhole, comprising:
flowing fluid through a body;
creating pressure in said body, said pressure causing slips on said
body to move to an engaged condition;
applying a force to said body so that said body engages a sealing
element; and
closing a valve in a bore of said body using said applied force.
According to another aspect of the present invention there is provided a
retrievable sealing device for downhole use, comprising:
a body having a bore along a longitudinal axis, said bore comprising a
valve; and
slips and a sealing element on said body, said slips being movable by
backpressure created by flow through said bore to an engaged condition, said
sealing element being actuable by a force in the direction of said
longitudinal
axis of said body with said slips in said engaged condition, said valve
closing
as a result of said force.
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BRIEF DESCRIPTION OF THE DRAWING
Figures 1 a-f are a sectional elevational view of the bridge plug and
packer in the run-in position.
Figures 2a-d illustrate the bridge plug in the set position with the packer
pulled away.
Figures 3a-d illustrate the packer in a set position after being pulled
away from the bridge plug.
Figures 4a-e illustrate the packer released and the bridge plug
recaptured prior to the release of the bridge plug.
Figure 5 illustrates the position of the pin in a J-slot mechanism for the
packer in the run-in position.
Figure 6 illustrates the position of the pin in a J-slot for the bridge plug
in the bridge plug set position just before release of the service packer from
the bridge plug.
Figure 7 is the view of Figure 5, showing the movement of the pin in the
J-slot as the packer is set in tension.
Figure 8 is the view of Figure 7, with the pin in the J-slot position for
recapture of the bridge plug.
Figure 9 is the view of Figure 6, with the pin in the position where the
bridge plug has been captured and released.
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DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
In the preferred embodiment, a packer P and a bridge plug BP are
connected together for run-in to a welibore (not shown) on coiled tubing or
threaded tubing or drill pipe (not shown) which is secured to the assembly at
thread 10. In the run-in position, relative movement between the cone 12 and
the slips 14 is not possible. The reason for this is that the slips 14 are con-
nected through a series of components to ratchet housing 16. Ratchet hous-
ing 16 has a groove 18. A series of segmented locking dogs 20, held together
by garter springs 22, are locked into groove 18 by virtue of lock collet
member
24. Lock collet member 24 has a groove 26 which, when aligned with dogs
20, aliows them to exit from groove 18. The slips 14 are pivotally mounted to
swivel retainer 28 and are biased outwardly by concentric springs 30. By
design, surface 32 is intended to rub on the tubing or casing (not shown) to
provide temporary support for the packer P in the setting operation as will be
described below. When the bridge plug BP and the packer P are connected
together for run-in, an elongated tubular stinger 34 extends into bore 36 of
the packer P. Stinger 34 has a surface 38 which supports collet heads 40 in
groove 42 of the upper body 44. Upper body 44 also has a pin 46 which
extends into an indexing assembly 48 located on ratchet housing 16 (see
Figures 1 a and 5). Upper body 44 also has a groove 50 whose purpose will
be explained below with the operation of the assembly. A spring 52, shown
in the compressed state in Figure 1 a, biases lock collet member 24 downward
when the collet heads 40 are liberated due to their movement away from
surface 38. In essence, when the collet heads 40 become liberated, the
spring 52 pushes them into groove 50, which puts groove 26 opposite dogs
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20, thus allowing them to come out of groove 18 under the power of garter
springs 22. This, in turn, allows operation of the pin 46 in the J-slot mecha-
nism 48 to accomplish the setting of the packer P, as will be explained below.
Packer P also has a sealing element 54 which is ultimately set by an
upward pull on top sub 56, which in turn brings the upper cone 12 under the
slips 14 and thereafter pulls bottom sub 58 upwardly, bringing it closer to
cone
12 and squeezing element 54 in the process. In this particular design, the set
of the packer P is held by retaining an upward tensile force on top sub 56.
Extending from bottom sub 58 is J-pin retainer 60. Retainer 60 holds
pin 62, which is operable in a series of slots 64 (see Figure 5). Slots 64 are
part of J-pin latch adapter 66. Latch adapter 66 has a plurality of collet
fingers 68 which terminate in collet heads 70, which during run-in are in
groove 72 of ball housing 74. Ball housing 74 has an opening 76 through
which extends index tab 78. Index tab 78 is a part of J-pin latch adapter 66,
Index tab 78 extends into groove 80 of ball shifting sleeve 82. Groove 80 is
longer than index tab 78, as shown in Figure 1 d. Sleeve 82 is operably
connected to ball 84, shown in the open position for run-in, with its openings
86 aligned with central bore 88, which allows flow through the assembled
packer P and bridge plug BP. This flow to create circulation assists in
running
the assembly of the bridge plug BP and the packer P into the hole. At the
bottom end of the assembly is choke 89 which, when flow is increased to a
predetermined amount, creates backpressure in bore 88. Other devices that
create backpressure in bore 88 can be used.
Also connected at the lower end of J-pin retainer 60 is a release probe
90. Release probe 90 has an internal shoulder 92 which retains snap latch
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94. Snap latch 94 is an annular ring that rides over snap latch collet 96.
Snap
latch collet 96 has an external shoulder 98 which retains snap latch 94 in
view
of the fact that the collet heads 100 are in contact with lower end 102 of
ball
housing 74. Lower body 104 is secured to ball housing 74 at thread 106.
Lower body 104 has an external shoulder 108 which defines a travel limit for
snap latch collet 96. It should be noted that the space between the lower end
102 of ball housing 74 and external shoulder 108 on lower body 104 is greater
than the length of snap latch collet 96 for reasons which will be explained
below.
Ball housing 74 has a groove 110 adjacent to groove 72 to retain collet
heads 70 after the bridge plug BP is set, as shown in Figure 2b, for reasons
which will be explained below.
The bridge plug BP is set by initially pressurizing bore 88 through an
increase of flow through choke 89. Pressure build-up in bore 88 results in a
build-up of pressure in chamber 112, which in turn drives slip extension
piston 114 under slip fingers 116. Movement of piston 114 compresses spring
118 as the slip fingers are pushed out for initial bite into the tubing or
casing
(not shown). An upward pull on the lower body 104 brings up guide 120 to
compress the elements 122, as well as bringing up lower cone 124 so that its
taper 126 cams the slip fingers 116 outwardly against the tubing or casing
(not
shown).
Body lock segments 128 are held to lower body 104 by garter springs
130. Segments 128 have a tooth profile 132 which rides on tooth profile 134
of lower body 104, thus the segments 128 help to retain the set of the bridge
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plug BP after a sufficient pick-up force on lower body 104 is applied with the
slips 116 engaged due to pressurization in chamber 112.
The major components of the assembly of the bridge plug BP and the
service packer P now having been described, the operation will be reviewed
in more detail.
In order to operate the assembly previously described, coiled or
threaded tubing or drillpipe is connected to threads 10 and the bridge plug-
BP
and packer P are lowered to the initial depth for setting of the bridge plug.
While the assembly is being lowered, circulation can occur through bore 36
which is connected to bore 88, with the openings 86 in ball 84 aligned with
bore 88. Circulation can proceed through choke 89. When the desired depth
is reached, the circulation rate is increased to increase the backpressure in
bore 88. This, in turn, drives piston 114, which in turn wedges the slips 116
outwardly against the casing or tubing (not shown). When this occurs, an
upward force is applied to lower body 104 through the coiled tubing from the
surface. The applied pickup force moves taper 126 under slips 116 to further
drive them into the casing or tubing (not shown). Additiona(ly, since the
slips
116 are now fixed against the casing or tubing (not shown), upward force
applied to the lower body 104 brings guide 120 Upwardly, compressing the
sealing elements 122 against lower cone 124. At the same time, tooth profile
134 is ratcheting past tooth profile 132 on body lock segments 128. As a
result of the upward force applied to lower body 104, the bridge plug BP is
set, with slips 116 firmly biting the casing or tubing (not shown) and the
seal-
ing elements 122 fully compressed.
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A further upward pull forces snap latch 94 over heads 100 which are
retained by ball housing 74. It should be noted that once the bridge plug BP
is set, an upward pull on top sub 56 is transmitted through upper body 44
through mandre1136 to bottom sub 58, which is in turn connected to. J-pin
retainer 60 and finally to release probe 90. Shoulder 92 pushes the snap
latch 94 such that it is radially expanded in order to clear the heads 100.
While a pickup force is being applied to top sub 56, J-pin retainer 60 is also
moving up so that pin 62 winds up in position 138 shown in Figure 6. When
this occurs, upward movement of J-pin retainer 60 takes with it J-pin latch
adapter 66 and moves tab 78 to shoulder 140 of ball shifting sleeve 82.
Further upward movement of top sub 56 will shift up ball shifting sleeve 82 so
that ball 84 rotates 900 to the position shown in Figure 2b, where the
openings
86 are misaligned with bore 88. This effectively closes off bore 88 with the
bridge plug BP in the set position.
To facilitate retaining the ball shifting sleeve 82 in the position with bore
88 closed, the collet heads 70 shift from groove 72 to groove 110, thus, due
to their inward bias, effectively holding tab 78 against shoulder 140, as
shown
in Figure 2b. As shown in Figure 2c, as a result of lifting snap latch 94 over
heads 100, snap latch coliet 96 has fallen down against shoulder 108 such
that heads 100 are no longer supported by lower end 102. The significance
of this will be explained at the retrieval portion of the description of the
pre-
ferred embodiment. The bridge plug BP has now been fully set and the ball
84 moved to the closed position. A setdown force is now applied to top sub
56, which advances pin 62 to position 143, shown in Figure 6, which upward
movement then allows pin 62 to move out of the slots 64 at 142. Further
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upward movement of top sub 56 will eventually allow the collet heads 40 to be
pulled away from surface 38 of stinger 34. Stinger 34 which is affixed to the
bridge plug BP stays put as top sub 56 continues to move up. It should be
noted that as long as the collet heads 40 are locked to groove 42 by virtue of
surface 38, the packer. P cannot be set. Upward movement of the packer P
relative to the set bridge plug BP frees up the packer P so that it can be set
at a desired location. Thus, when collet heads 40 are clear of surface 38,
spring 52 pushes lock collet member 24 downwardly until groove 26 is aligned
with dogs 20, thus undermining support for dogs 20. The garter springs 22
move the dogs 20 radially inwardly, thus releasing ratchet housing 16 from
upper body 44. The packer P is brought to its desired location and surfaces
32, which act as drag blocks under the force of springs 30, temporarily sup-
port the packer P to facilitate its setting. Thus, when the proper depth is
reached for setting of packer P, a setdown force is applied, moving the pin 46
to position 145, shown in Figure 5. A pickup force is then applied, moving pin
46 along groove marked 146 in Figure 5. Since groove 146 is longer than
adjacent groove 148, the mandrel 136 can come up, taking with it bottom sub
58 as well as cone 12. Taper 150 on cone 12 catches taper 152 on slips 14
to force them outwardly against the casing or tubing (not shown). Once that
occurs, further upward pickup force on top sub 56 brings bottom sub 58
against the sealing element 54 to compress it against the tubing or casing
(not
shown). This occurs because the bottom sub 58 moves closer to cone 12,
which becomes immobile when it pushes slips 14 against the casing or tubing
(not shown). This final position with the packer P in the set position is
illus-
trated in Figures 3a-d. Figure 7 shows the position of pin 46 in groove 146
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while tension is held on the packer P to hold its set. While Figure 3d shows
the J-pin retainer 60 still over the stinger 34, those skilled in the art will
ap-
preciate that the packer P can be set anywhere once the pin 62 is allowed to
exit the slot assembly 64 through position 142. If rigid tubing is used, the
packer P can also be of the type that sets or releases with rotation when used
in conjunction with a bridge plug BP which is set without rotation. Alterna-
tively, the packer P and bridge plug BP can both be set with some rotation.
Those skilled in the art will now appreciate some of the benefits of the
assembly described. In more general terms, a bridge plug BP and a packer
P can be run in the hole, particularly on coiled tubing, and set without
rotation.
Thus, in deviated welibores or even horizontal wellbores where coiled tubing
use is prevalent, the assembly described above can be used to isolate a zone
of any predetermined length. The separation between the bridge plug BP and
the packer P occurs downhole. The packer P is locked against setting until
after the packer P is released from the bridge plug BP, with the bridge plug
BP already in a set position. The assembly facilitates circulation during run-
in
by leaving bore 88 open through positioning of ball 84. The setting of the
bridge plug BP incorporates in it the closure of bore 88 through the 900
rotation of ball 84. Thus, when the packer P is disconnected from the bridge
plug BP, the bridge plug BP is set in the casing or tubing (not shown) in a
sealing manner, with the internal passage 88 closed off by virtue of ball 84.
The packer P can then be set in any desired position and will not set until it
is
separated from the stinger 34, raised to its proper position, lowered and
raised
again so that it can be held in the set position shown in Figure 3 under an
applied tensile load. Those skilled in the art will appreciate that although
the
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packer P has been shown to be a tension-set packer, it can also be
compression-set or hydraulically set as an inflatable. The bridge plug BP has
been illustrated as being set by a combination of fluid pressure and a longitu-
dinal force. However, other types of bridge plugs are within the scope of the
invention, particularly when they can be set without rotation. Other types of
tools can also be used instead of a packer P or bridge plug,BP. Anchors,
which don't seal, or a whipstock are just a few examples.
As previously stated, the assembly of the bridge plug BP and the
packer P can be redeployed without tripping out of the wellbore. Leading up
to redeployment is the procedure to release the packer P and reconnect it to
the bridge plug BP just before releasing the bridge plug BP. When all that
occurs, the run-in position of Figure 1 is reobtained and the whole process
can be repeated as many times as necessary. Accordingly, when the forma-
tion treatment through the coiled tubing (not shown) between the elements 54
and 122 is compieted, it is desirable to release the set of the packer 54. A
setdown force is applied to top sub 56, moving the pin 46 to the position 144
shown in Figure 8. As the packer P is lowered to contact the bridge plug BP,
shoulder 154 on stinger 34 eventually contacts the collet heads 40 (see Figure
3d). Shoulder 154 pushes the collet heads 40, which are at this time located
in groove 50, against the force of spring 52. Previously, spring 52 had been
holding groove 26 adjacent the dogs 20 so that they can stay in the retracted
position illustrated in Figure 3a. However, when the shoulder 154 on the
stinger 34 pushes the collet heads 40 into groove 42, the top sub 56 has
landed on ratchet housing 16, putting groove 18 opposite dogs 20. Therefore,
as the coilet heads 40 are displaced by shoulder 154, groove 26 forces dogs
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20 outwardly into groove 18, such that the position shown in Figure 4a is
assumed.
At this time, further setdown force on top sub 56 brings the BP pin 62
into position 142 of the ratchet shown in Figure 5. At this time the snap
latch
collet 96 is against shoulder 108, allowing the heads 100 to flex radially
inwardly into recess 156 as the snap latch 94 is pushed over the collet heads
100. The packer P is now secured to the bridge plug BP. While this is hap-
pening, the J-pin latch adapter 66 is pushed downwardly, pushing tab 78
away from shoulder 140 in groove 80. As this occurs, the collet heads 70 are
forced from groove 110 into groove 72 (see Figure 4d). The downward
shifting of tab 78 moves ball shifting sleeve 82 downwardly to rotate ball 84
into the open position shown in Figure 4d. At this time the bridge plug BP is
still set but differential pressure has now been.equalized through the
rotation
of ball 84. At this time a pickup force is applied which advances pin 62 to
position 160 shown in Figure 9. The snap latch 94 shoulders against the
collet heads 100. The bridge plug BP can then be released by a setdown
force on top sub 56 which moves the pin 62 to position 158 shown in Figure
9. The lower end 160 of the release probe 90 (see Figure 4d) gets under
body lock segments 128 and pushesthem upwardly so as, to disengage tooth
profiles 132 and 134. A further downward force pulls out the lower cone 124
from under the slips 116 while extending the sealing elements 122. The
bridge plug BP is now released, and the spring 118 pushes the slips 116
upwardly so that they can retract to the position shown in Figure 1 e. A
pickup
force will reposition the pin 62 at position 156 which, in turn, brings the
snap
latch 94 against the collet heads 100. In essence, the position of Figure 1 is
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resumed, allowing the assembly to be repositioned in the welibore for a
repetition of the procedure at a different location.
The foregoing disclosure and description of the invention are illustrative
and explanatory thereof, and various changes in the size, shape and materi-
als, as weli as in the details of the illustrated. construction, may be made
without depart ing from the spirit of the invention.
bakerlpatents\552 m3a for posftioning wnh rotation.wpd ss
