Note: Descriptions are shown in the official language in which they were submitted.
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1
TOOLGUIDE FOR CREATING DEVIATED SOFt'EHOI,E SRANCAES FROM A
WE7.,I. BORE
FIELD OF THE IIaVENTION
The present invention is directed to a borehole
drilling assembly and in particular to an assembly for
drilling and completing deviated boreholes,
BACKGROUND OF THE INVEN'I'ION
Deviated boreholes are drj.lled using whipstock
assemblies. A whipstock is a device which can be secured
in the casing of a well and which has a tapered, sloping
upper surface that acts to guide well bore tools along the
tapered surface and in a selected direction away from the
straight course of the well bore.
To facilitate the use of a whipstock, a section
of casing is used which has premilled window openings
through which deviated well bores can be drilled. The
whipstock can be positioned relative to the window using a
landing system which comprises a plurality of stacked
spacers mounted on a fixed mounting device at the bottom of
the casing and defining at the top thereof a whipstock
retaining receptacle, or by use of a latch between the
whipstock and the casing. A stacked landing system can
cause difficulty in aligning the whipstock with the window
opening as the distance between the mounting device and the
window increases. The whipstock may also turn during the
drilling or setting processes resulting in the deviated
well bore being directed incorrectly and/or the well bore
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la
tools being stuck in the wellbore. Sometimes a latch
system is used to overcome some of these disadvantages.
However, the latch can sometimes disengage between the
whipstock and the casing, allowing the whipstock to turn or
move down in the casing.
After the deviated wellbore is drilled, it can be
left uncompleted or completed in any suitable way. To seal
the deviated wellbore hydraulically from the main casing, a
liner
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2
can be installed and cement can be pumped behind the liner. This is expensive
and
often creates obstructions in the main casing which complicates removal and
run of the
tools.
When the tools are used in horizontal primary bores, new problems arise.
Running and
retrieval tools which are useful for vertical tool manipulation are not always
useful in
horizontal applications.
SUMMARY OF THE INVENTION
An assembly for drilling and/or completing a deviated wellbore has been
invented, In
one aspect the assembly includes a tooiguide which can be positioned relative
to a
window opening in a casing section and releasably locked in position. The
toolguide
or portions thereof can have applied thereto a coating which prevents damage
to the
metal components of the tooiguide and facilitates removal of the tooiguide
from the
wellbore after use.
In accordance with a broad aspect of the present invention, there is provided
a tool
guide for creating deviated borehole branches from a wellbore comprising an
upper
section including a sloping face portion and a lower orienting section,
including at least
one latch biased radially outwardly from the orienting section and positioned
in a known
orientation relative to the sloping face portion and a latch locking means to
releasably
lock the latch in an extended position, the latch locking means being actuated
to lock
the latch by torsion of the upper section relative to the lower orienting
section.
Each latch of the orienting section is selected to fit within and lock into
its own latch
receiving slot formed in the casing. When the latch of the orienting section
is locked
into the latch receiving slot the tooiguide will be maintained in position in
the casing.
Preferably, the casing includes at least one premilled window opening
positioned in
known relation relative to the latch receiving slot. Preferably, a removable
liner can be
positioned in the casing to close the window opening temporarily and to cover
the latch
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receiving slot.
The orienting section can be releasably connected to the upper section. Such
connection is preferably by connectors such as, for example, shear.pins to the
upper
section so that these parts can be installed together into the casing.
Preferably, the
connectors are selected such that the sections can be separated by an
application of
force sufficient to overcome the strength of the connectors. This permits the
upper
section and the lower section to be separated and removed separately should
one part
become stuck in the casing.
The sections are movable relative to one another and means are provided to
translate
such movement to actuate such means as a seal.
Preferably, the lower orienting section includes a mandrel engaged slidably
and
rotatably within an outer housing. The mandrel is releasably connected to the
upper
section and moveable with the upper section. Preferably, the latch locking
means is an
extension of the mandrel. The extension can be formed to fit behind the latch
to lock
it in the outwardly biased position.
According to a further aspect of the present invention, there is provided a
toolguide for
creating borehole branches from a wellbore, the tooiguide having a
longitudinal axis
and comprising an upper section including a sloping face portion, a lower
orienting
section, the upper section and the lower orienting section being connected and
moveable relative to each other along the longitudinal axis of the toolguide,
and an
annular sealing means mounted below the upper section, the annular sealing
means
being actuatable to expand and retract upon movement of the upper section and
the
lower orienting section relative to one another.
In one embodiment, the upper section is attached to a central mandrel of the
lower
orienting section. The central mandrel is engaged slidably and rotatably
within an outer
housing of the lower orienting section. The outer housing carries the annular
sealing
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means which is actuatable to expand or retract by movement of the mandrel
within the
outer housing. Preferably, the outer housing includes a first section and a
second
section and disposed therebetween the annular sealing means. The first section
is
moveable toward the second section to compress the annular sealing means
therebetween and cause it to expand outwardly. In this embodiment, preferably
the
mandrel has a shouider positioned thereon to abut against the first section
and limit the
movement of the mandrel into the outer housing. Abutment of the shoulder
against the
first section causes the first section of the housing to be driven it towards
the second
section and the annular sealing means to be compressed and expanded outwardly.
According to another broad aspect of the present invention, there is provided
an upper
section for a toolguide for use in creating wellbore branches from a well
bore, the upper
section being formed of a first material and having a surface and comprising a
coating
material disposed at least over a portion of its surface, the coating material
being softer
than the first material and being resistant to oil and gas.
Preferably, the coating material comprises polymers such as epoxy and/or
polyurethane. The polymer is preferably coated onto the tool by use of a mold,
so that
the shape of the tool after coating is controllable. If damage occurs to the
coating, it
can be replaced.
In accordance with yet another broad aspect of the present invention, there is
provided
a casing section for a deviated welibore junction comprising a cylindrical
casing tube
having a central axis and a window opening formed therein and a sleeve having
an
opening therein, the sleeve being mounted relative to the casing tube to move
between
a first position in which the opening of the sleeve is aligned with the window
opening
of the casing tube and a second position in which the opening of the sleeve is
not
aligned with the window opening of the casing tube.
According to another broad aspect, there is provided a casing section for a
deviated
wellbore junction comprising a casing tube having a central axis and a window
opening
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formed therein and a sleeve having a first opening and a
second opening therein, the sleeve being mounted relative
to the casing tube to move between a first position in
which the first opening of the sleeve is aligned with the
5 window opening of the casing tube and a second position in
which the second opening of -L-he sleeve is aligned with the
window opening of the casing tube.
Preferably, sealing means are disposed between
the casing tube ancl the sleeve. These sealing means are
preferably selected to effect a hydraulic seal between the
parts. In one embodiment, the sealing means is formed of
deformable material such as rubber or plastic and is
disposed around the opening of the sleeve and along the top
and bottom thereof.
In one embodiment, the sleeve is disposed within
the casing tube in a counterbore formed therein such that
the inner diameter of the sleeve is greater than or
substantially equal to the inner diameter of the casing
away from the position of the sleeve.
Preferably, the window of the casing is formed to
accept a flange of a junction fitting such as, for example,
a tieback hanger of a branched weilbore. In a preferred
embodiment, the sleeve is selected to seal against the
flange of the fitting.
in a preferred embodiment, the sleeve has formed
therethrough two openings. The first opening is sized to
allow access to the window opening of the casing section by
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cieviated borehole tools and the second opening is smaller
than the first opening.
In accordance with a further broad aspect of the
present invention, there is provided a tool guide for
creating deviated borehole branches from a well bore
comprising: an upper section including a sloping face
portion; and a lower orienting section, including at least
one latch biased radially outwardly from the orienting
section and positioned in a known orientation relative to
the sloping face portion, an outer housing and a latch
locking means to releasably lock the latch in an extended
position, the latch locking means being actuated to look
the latch by releas.Lng the weight of the upper section onto
the lower section.
BRIEF DESCRIPTZON OF THL DRAN'.LNGS
A further, detailed, description of the
invention, briefly described above, will follow by
reference to the following drawings of specific embodiments
of the invention. These drawings depict only typical
embodiments of the invention and are therefore not to be
-considered limiting of its scope. In the drawings:
Figure 1 is a schematic representation of an
embodiment of an assembly according to the present
invention, the assembly being positioned in a wellbore;
Figure 2 is a view showing the orientation of
Figures 2a and 2b.
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Figures 2a and 2b are longitudinal secticrs along
a casing section for a deviated wellbore jLtnction useful in
the present invention;
Figure 3A is a view showing the orientation of
Figures 3A-a and 3A-b;
Figures 3A-a and 3A-b are a front elevation view,
partly cutaway, of a whipstock of a toolguide according to
the present invention;
Figure 3B is a view showing the orientation of
Fiqures 3B-a and 3B-b;
Figures 3B-a and 3B-b are a section along
line 3B-3B of Figure 3A;
Figure 4A is a view showing the orientation of
F'igures 4A-a and 4A-b;
Figures 4A-a and 41a-b are a front elevation view,
partly cutaway, of a whipstock of another toolguide;
Figure 4B is a view showing the orientation of
Figures 4B--a and 4B-b;
Figures 4B-a and 4B-b are a section along line
4B-4B of Figure 4A;
Figures 4C and 4D are sectional views along line
4C-4C and 4D-4D, respectively, of Figure 4B;
Figure 4E is a bottom end view of Figure 4A;
Figure 4F is a top end view of Figure qA;
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Figure 5A is a front elevation view of a lower
section of a toolguide according to the present invention,
partly in section and in un-compressed configuration;
Figure 5B is a front elevation view of the
toolguide of Figure 5A in compressed configuration;
Figure 5C is a section along line 5C-5C of
Figure 5A;
Figure 6A is a view showing the orientation of
Figures 6Aa and 6Ab;
Figures 6Aa and 6Ab are longitudinal sections
along another lower section of a toolguide in a set
configuration;
Figure 6B is a view showing the orientation of
Figur.es 6Ba and 6Bb;
Figuxes 6Ba and 6Bb are longitudinal sections
along another lower section of a toolguide;
Figure 7 is a view showing 'the orientation of
Figures 7A to 7C;
Figures 7A to 7C are longitudinal sections along
a casing section for a deviated wellbore junction;
Figure 8 is a view showing the orientation ot
Figures 8a and 8b;
Figures 8a and 8b are longitudinal sectional
views along a runnirig/retrieving tool;
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Figure 9 is a longitudinal section along another
casing section for a deviated wellbore junction according
to the present invention;
Figure 10 is a rear plan view of a sleeve
according to the present invention in flattened
configuration;
Figure 11A is a sectional view through a deviated
wellbore junction using a casing section according to the
present invention;
Figure 11B is a front elevation view of a tieback
hanger;
Figure 11C is a front elevation view of a tieback
hanger;
Figure 12 is a front elevation view of another
sleeve according to the present invention in flattened
configuration;
Figure 13 is a view showing the orientation of
Figures 13a and 13b;
Figures 13a and 13b are elevation views of a
casing section including a window opening;
Figure 14 is a longitudinal sectional view along
a liner positioning tool;
Figure 15 is a schematic representation of a
system for imparting rotational force on a drill pipe;
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9a
Figure 16A is a longitudinal sectional view along
a eleeve shifting tool according to the present invention;
Figure 16B is front elevation view of a portion
of the sleeve shifting tool of Figure 16A showing the
sleeve engaging slips;
Figure 17 is an elevation view of a casing
sectzon including a window opening according to the present
invention;
Figure 17A is a sectional view along line A-A of
Figure 17;
Figure 17B is a sectional view along line B-B of
Figure 17;
Figure 17C is an enlarged view of an edge of the
window opening, as noted in Figure 17A;
Figure 18 is a front elevation view of a tieback
hanger in accordance with another aspect of the present
invention;
Figure 18A is a sectional view along line A-A of
Figure 18 showing the lower setting tab;
Figure 183 is a sectional view along line B-B of
Figure 18 showing the mid setting flanges;
Figure 1BC is a sectional view along line C-C of
Figure 18 showing the upper setting tab;
Figure 19A is a sectional view through a casing
section according to Figure 17 having a tieback hanger
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9b
according to Figure 18 therein with zhe upper setting tab
in unengaged position; and
Figure 19B is a sectional view as in Figure 19A
with the upper setting tab in engaged position in the
window of the casing seCtion.
DETAILED DESCRIPTION OF THE PREFERRED EbIDODIMENTS
For the pufposes of clarity, in the Figures only
reference numerals of the main components are indicated and
liko reference numerals relate to like components.
Referring to Figure 1, there is shown a tubular
wellbore casing 2 for installation in a primary wellbore 4
drilled t:hrough a formation. Primary wellbore 4 can be a
main wellbore directly opening to surface or a lateral
wellbore drilled from a main wellbore. Primary wellbore
can range between a vertical and a horizontal orientation.
Casing 2 includes upper and lower sections of production
casing 6 and secured therebetween a casing section 8 for
use in deviated wellbore junctions. The deviated wellbores
branch from wellbore 4.
Casing sections 6 and 8 are connected by standard
connectors 9 or any other suitable means. A float collar
10 is provided at the lower end of casing 2 which allows
fluids to flow out of the casing but prevents flow of fluid
and debris back into wellbore casing 2. Any similar one
way valve can be used in the place of float collar 10. By
a completion procedure, cement 11 is disposed in the casing
annulus.
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Casing section B includes a window in the form of
an elongazed opening 12 extending in the longitudinal
direction of easing B. In use, opening 12 is oriented
toward the desired direction ot a deviated wellboxe to be
drilled, shown in phantom at 14. The window is sized and
shaped with reference to the desired diameter and azimuth
of the deviated wellbore to be drilled and the diameter of
the casing, as is known in the art.
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lqw
Casing section 8 further has formed therein a latch receiving slot 16a at a
selected
orientation relative to window opening 12. The latch receiving slot can be
oriented at
any point around the interior circumference of the casing section, so long as
its position
is known with respect to the window opening. Preferably, latch receiving slot
16a is
5 aligned with the longitudinal axis of window 12, as shown, or is directly
opposite window
opening 12.
A tooiguide 18 is installed in casing 2 with its latch 20 extending into slot
16a. Toolguide
18 includes a lower orienting section 22, also called a monopositioning tool,
from which
latch 20 is biased radially outwardly, and an upper section 24, commonly
called a
10 whipstock, having a sloping face portion 26. Sections 22 and 24 are
connected so that
they are not free to rotate relative to each other, whereby face portion 26 is
maintained
in a fixed and known orientation relative to latch 20. In a preferred
embodiment, as
shown, latch 20 is aligned at the bottom of sloping face portion 26, so that
the surface
of the sloping face portion will be aligned opposite window opening 12, when
latch 20
is in slot 16a.
An annular expandable seal 28 is disposed on toolguide 18 below sloping face
portion
26. The seal 28 when expanded, acts to prevent debris and fluids from passing
down
the wellbore. Seal 28 is therefore selected to have an outer diameter, when
expanded,
which is greater than the inner diameter of the casing 2 in which it is to be
used.
Toolguide 18 is placed in casing 2 by use of a running tool 30 which
releasably locks
onto upper section 24 and is shown in this drawing still attached to the upper
section.
Running tool 30 is connected to a drill pipe 32.
To remove the tooiguide from the wellbore, a retrieving tool can be used. In
one
embodiment shown in Figure 13, one tool is provided which is useful for both
running
and retrieving operations.
To prepare for the drilling of a deviated borehole, such as that shown at 14,
the
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wellbore casing 2 is installed and completed. Figure 2 shows apparatus useful
for
permitting completion of the well while preserving features used in the
invention.
Casing section 8 is milled to include a window opening 12 and a latch
receiving slot
16a. Preferably, a slot 17 (Figure 2) for alignment of retrieval tools is also
milled out in
casing section 8. Preferably, window opening 12 and latch receiving slot 16a
are
aligned along the casing.
A liner 34 is positioned in casing 8 and seals 36a and 36b are provided
between liner
34 and casing 8. A float collar 38 and an orienting subassembly 39 are
attached above
liner 34. Float collar 38 and orienting subassembly 39 can be positioned, as
shown, or
can be positioned further up the casing provided orienting subassemby is in a
known
configuration relative to window opining 12. Preferably, a removable filler
41, such as
foam, is inserted between casing 8 and liner 34 between seals 36b to fill
window
opening 12 and the casing section 8 is wrapped in a rigid material 40, such as
fibre
glass or composite tape, to cover at least opening 12.
Preferably, slots 16a and 17 are filled with filling materials such as grease
and/or foam
to prevent materials from entering into the slots and the remainder of spaces
43,
defined between casing 8, liner 34 and seals 36a, 36b, are filled with cement.
To
further prevent entry of materials into slots 16a, 17, caps 44 are welded onto
the outer
surface of casing 8 over the slots.
Casing 8, including the parts as noted hereinbefore, is connected to casing
sections 6
to form casing string 2 and float collar 10 is attached. Casing string 2 is
lowered Into
wellbore 4. The casing string is rotated until window opening 12 is oriented
in the
direction in which it is desired that the deviated welfbore 14 should extend.
Suitable
methods are well known in the oil industry for orienting downhole tools, for
example,
using a surface reading gyro, a mule shoe or other suitable means.
The cased wellbore is completed by forcing cement through the casing string
and into
the annulus between the casing and the wellbore. During completion, the cement
is
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forced through float collar 38 and liner 34 but is prevented from entry behind
liner 34
by seals 36a and the cement and fillers in spaces 43. (It is to be understood
that only
one float collar is needed and float collar 10 need not be used when float
collar 38 is
used.) As the cement fills the casing annulus, it is prevented from entering
slot 16a by
cap 44 and is prevented from entering window opening 12 by the filler 41 and
rigid
materials 40. The cement is allowed time to set.
After completion, a drill (not shown) of a diameter selected to be
approximately equal
to the inner diameter of the casing is run into the well to remove cement from
the casing
bore. The drill will also drill out liner 34, seals 36a, 36b, float collar 38
and cement in
spaces 43. Thus, liner 34 is formed of a material such as, for example,
aluminum, fibre
glass, or carbon fibre-containing composite, which can be removed by drilling.
Where
aluminum is used in the we(lbore, preferably any aluminum surfaces exposed for
contact by cement, which will be used in the completion operation, are coated
with a
suitable material, such as rubber cement, to prevent degradation of the
aluminum by
contact with cement.
The casing is then ready for production or for drilling deviated wellbores.
Where
deviated wellbores are to be drilled a toolguide 18 will be run in and
oriented in the
casing as shown in Figure 1.
In Figures 3A and 3B and Figures 4A to 4F, two embodiments of an upper section
according to the present invention are shown. Referring to Figures 3A and 3B,
an
upper section 24 tapers toward its upper end to form a sloping face portion 26
which
is formed to direct any tool pushed along it laterally outwardly at a selected
angle. The
face portion is machined to have a selected slope x or range of slopes with
respect to
long axis 52 of the section depending on the build radius desired for the
deviated
wellbore. As an example, when x is 40, the build radius will be approximately
15 /30
meters drilled. Preferably, sloping face portion 26 is formed to be concave
along its
width.
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An entry guide 49 is welded at the top of face portion 26. Entry guide 49
assists in
centralization and tool retrieval and need only be used, as desired. A bore 50
extends
a selected distance through the upper section parallel to its central axis 52.
Bore 50 is
formed to engage a fishing spear device and provides one means of retrieving
the
tooiguide from the wellbore. Extending back from face portion are slots 53
formed to
accept and retain a retrieval tool having corresponding sized and spaced hooks
thereon. Also formed on face portion 26 are apertures 54 formed to accept
shear pins
(not shown) for attachment to running tool 30 (Figure 1).
Centralizers 56 are spaced about the upper section. While only one centralizer
is
illustrated in the drawing, there are preferably at least three centralizers
on the upper
portion to center the upper section in the hole.
A socket 58 extends from the bottom of upper section 24 parallel with central
axis 52.
Socket 58 is shaped to accept a male portion 68 on the lower orienting section
22, as
will be discussed hereinafter with reference to Figures 5A and 5B. Preferably,
socket
58 is faceted at 60 and male portion is similarly faceted so that the parts
lock together
and male portion 68 cannot rotate within socket 58. Shear pins 61 are inserted
through
apertures 62 to secure male portion 68 in socket 58 and thereby, the upper
section to
the lower section.
The upper section is formed of hardened steel. The outer diameter of the upper
section
is selected to be smaller than the inner diameter of the casing in which it is
to be used.
Upper section 24 has applied thereto a polymeric coating 64 (shown only in
Figure 3B).
Polymeric coating 64 is preferably formed of cured polyurethane. Coating 64
acts to
prevent damage of the metal components of the upper section and can be
reapplied if
it is removed during use. Coating 64 further facilitates wash over operations,
should
they become necessary to remove the toolguide or upper section from the
casing. The
coating is thick enough so that it will accommodate normal damage from, for
example,
abrasion and will prevent damage to the metal surfaces of the upper section
and is
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14
preferably also thick enough so that substantially only the coating will be
removed by
any washover operation. In a preferred embodiment, the coating is about'/:
inch thick
and is applied using a mold.
Because coating 64 is easily abradable and deformable, the coating can
interfere with
tool centralization. Thus, to permit correct centralization of the upper
section within the
casing, preferably centralizers 56 extend out from the metal portion of the
upper section
a distance at least equal with the thickness of coating 64. In this way,
centralizers 56
are either flush with the surface of the coating or extend out therefrom.
Referring to Figures 4A to 4F, another upper section 24' is shown. Upper
section 24'
includes a sloping face portion 26'. Generally, upper sections are useful for
producing
only one of a long, medium or short radius deviated weilbore. However, the
profile of
sloping face portion 26' of section 24' is formed to allow flexibility to
produce both
medium and short radius laterals.
Upper section 24' is selected to be useful with a running/retrieval tool as is
described
in more detail in Figure 13. In particular, upper section 24' has formed at
its upper end
a dove-tail slot 51 and a second slot 55. These slots will be described in
more detail
with respect to Figure 13.
Centralizers 56' are formed integral with the metal portion of the upper
section. While
six centralizers are shown, it is to be understood that only three
centralizers are
required for proper functioning.
Upper section includes a socket 58' which is generally similar to socket 58
described
with reference to Figure 3B. Socket 58' includes a faceted portion 68.
Apertures 62
extend through centralizers 56' and open into socket 58' for accepting shear
pins (61'
in figure 6) for securing the upper section to the lower section.
A coating 64' of polymeric material is applied over selected portions of the
upper
CA 02527161 1998-08-18
section. As noted with respect to Figure 3B, preferably coating 64' is applied
to be flush
with the outer, contact surface of centralizers 56'. It has been found that in
upper
sections having a coating applied for washover purposes, the smaller diameter
can
reduce the width of the sloping face profile and can compromise drill guidance
along
5 the face and stability of the upper section. To provide greater lateral
stabil'ity across the
width of sloping face portion 26' and to provide centralization and stability
to the upper
tapered end of the upper section, a lip 65 extends out from face portion 26.
Coating
64' is built up against lip 65. The lip is preferably 1/2" to 1" thick.
10 In Figures 5A and 5B, one embodiment of a lower orienting section 22 is
shown. Figure
6 shows another embodiment of a lower orienting section 22'. Any upper section
can
be used with these lower sections, provided that the upper sections have a
socket for
connection to the lower sections. In particular, either of sections 24 or 24'
can be
mounted on either of the lower sections described with reference to Figure 5A
or Figure
15 6.
Section 22 is shown uncompressed in Figure 5A. In Figure 5B, section 22 is
shown in
a compressed, set condition as would be the condition of the section when used
in a
toolguide which is locked in position in a wellbore ready for use. Lower
orienting
section 22 includes a male portion 68 shaped to fit into the sockets 58 or 58'
on the
upper sections. Bores 70 (only one is shown) accept ends of shear pins 61.
Male portion 68 is connected to a central mandrel 72. Central mandrel 72 is
mounted
in a bore 73 in a housing 74. Mandrel 72 is both moveable through and
rotatable within
bore 73 as limited by movement of pin 76 on housing 74 in jay slot 78 formed
in
mandrel 72. Mandrel 72 can be releasably locked in position in housing by
locking
collet 77 frictionally engaging into knurled area 77a.
Housing 74 includes a top portion 80 and a lower portion 82. Each portion has
a flange
84 which together retain an annular packing seal 28. Top portion 80 is
moveable
towards lower portion 82 as shown in Figure 5B to compress packing seal 28 and
cause
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16
it to expand outwardly.
Referring also to Figure 5C, housing 74 at its
lower end accommodates latch assembly 83. Latch assembly
83 includes latch 20, a latch retaining plate 85 and
springs 86. Springs 86 act between latch 20 and latch
retaining plate 85 to bias latch 20 radially outwardly from
housing 74. Latch 20 is retained in a channel 88 through
housing 74 which opens into bore 73. Latch 20 is prevented
from being forced by the action of springs 86 out of the
channel, by abutting flanges 90 which act against shoulders
92 on the latch. Latch 20 can be pushed into channel 88 by
application of force on the latch toward plate 85.
Latch 20 is formed to fit into latch retaining
slot 16a on casing 8 and has a ramped surface 94 on its
upper edge, to ease removal from the slot, and an acute
angle portion 96 which acts as a catch on its lower edge to
resist against the latch moving out of the slot by any
downward force.
Mandrel 72 is bifurcated at its lower end to form
two arms 98a, 98b. Arms 98a, 98b are formed to be
extendable through bore 73 on either side of latch 20.
Arms 98a, 98b are generally wedge-shaped to permit rotation
of mandrel 72 in bore 73. As mandrel rotates, arms 98a,
98b are driven from a position in which they do not
restrict movement of the latch in the channel to a position
in which arm 98a abuts against shoulder 99 of latch 20 and
prevents it from moving back into channel 88. In this way
98a can be moved to act as a lock against retraction of
latch 20 into channel 88. Arm 98b serves to stabilize the
CA 02527161 2008-03-25
79350-180D
17
end of the mandrel, but, can be omitted from the mandrel,
as desired.
In use, a toolguide is constructed by attaching
an upper section (ie. Figure 3A or Figure 4A) to lower
section 22 by insertion of shear pins 61 through apertures
62 and 70. The toolguide is run into the well until the
latch 20 is about 1 meter below the slot 16a in casing
section S. The toolguide is hoisted and rotated slowly,
until latch 20 is located in slot 16a. When the latch is
located in the slot, the torque load will suddenly
increas.e. As the string torques up, jay pin 76 will
release, allowing mandrel 72 to rotate in a direc-L-ion
indicated by arrow a. When the force on the toolguide is
released, the mandrel will be free to move down in
housing 74 (Figure 58). During rotation of the mandrel,
arms 98a, 98b will be rotated so that arm 98a abuts against
shoulder 99 of latch 20 and locks latch in the outwardly
biased position. Mandrel arms can take other forms
provided they are formed to lock behind the latch in
response to rotation of the mandrel and/or movement of the
mandrel through the housing.
A downward movement of the string allows the
toolguide to travel down until portion 96 of the latch
lands against the bottom of slot 16a. Latch 20 and
- housing 74 will support the weight of the tool and upper
portion of the housing will be driven down by the weight of
the upper section to compress seal 28 allowing it to set.
The set force is locked in by collet 77. The upper
CA 02527161 2008-06-19
79350-180D
17a
section 24 is now aligned with window opening 12 and the
directional drilling operations can begin.
After the directional drilling operations are
completed, a retrieving tool is run in to retrieve the
toolguide. Preferably, in the simplest retrieval
procedure, a straight upward force, for example of about
20,000 psi on the toolguide will unlock locking collet 77
and permit mandrel 72 to be pulled up. This pulls arm 98a
out of abutting engagement with the latch and releases seal
28. The toolguide can then be removed from the well.
If the toolguide gets stuck in the well, a force
is applied which is sufficient to shear pins 61 so that the
upper section can be removed separately from the lower
section.
Referring to Figure 6A, another lower section 22'
is shown connected to an upper section 24'. Lower section
22' includes a male portion 68' shaped to fit into socket
58' of section 24'. Bores 70' accept ends of shear
pins 61'.
Male portion 68' is an extension of a mandrel 172
which is positioned in a bore 173 in housing 174. Mandrel
172 is slidably moveable through bore 173 along long axis
178 of the lower section, but can be releasably locked
against longitudinal sliding movement by frictional
engagement of locking collet 177 against knurled
portion 177a of the
CA 02527161 1998-08-18
18
mandrel. Mandrel 172 and bore 173 are correspondingly faceted along
corresponding
portions of their length to substantially prevent rotational movement of
mandrel 172
within bore 173.
An annular packing seal 28 is retained on housing 174 and a tube 179 is
positioned to
ride over an upper surface of housing 174. Tube 179 is releasably secured
through
shear pins 179a to upper section 24' to move therewith. Pressure of tube 179
against
annular packing seal 28, for example when the weight of the upper section is
released
onto the lower section, compresses the seal and causes it to expand outwardly.
Lower section 22' carries a latch assembly 183 including a latch 20', a latch
retaining
plate 184 and latch biasing springs 186. Springs 186 act between latch 20' and
plate
184 to bias latch 20' to extend radially outwardly from housing 174. Latch 20'
is formed
to fit into a latch retaining slot, such as 16a in Figure 1, as noted with
reference to latch
of Figure 5B.
Latch 20' is retained in a channel 188 which opens into bore 173. Latch 20' is
15 prevented from being forced by the action of springs 186 out of channel 188
by abutting
flanges 190 which act against shoulders 191 on the latch. Latch 20' has formed
into
its surface an upper cavity 192 and a lower cavity 193.
Mandrel 172 has an extension 198 on its lower end which is capable of fitting
into cavity
192 when mandrel is advanced toward the latch. When extension 198 of mandrel
172
20 fits into the cavity, latch 20' is prevented from moving back into channel
188 and,
thereby is locked in an outwardly extending position. To strengthen the
locking of latch
20' in the outward position, the latch preferably has formed thereon a cavity
on each
side thereof for accepting a pair of spaced extensions on the mandrel.
A rod 199 extends below latch 20. Rod 199 extends in bore 200 and is slidably
moveable therein. Rod 199 and bore 200 are correspondingly faceted along at
least
a portion of their lengths so that rod 199 is substantially prevented from
rotating within
CA 02527161 1998-08-18
78543-124D
- 19
the bore. Rod 199 has an end 199' which is capable of fitting into cavity 193
on latich
20'. Cavrty 193 and end 199' are tormed, as by shaping, such that cavity 193
wiil only
accept end 199' therein when end 199' is directly aligned with the cavity.
When end
199' is inserted into cavity 193, the latch is maintained in a recessed
position in- the
channel and is prevented from being biased to extend fully outwardly.
Thus,.rod 199
acts as a lock for latch 20'. Apertures 201 are formed through housing 174 for
alignment with holes 202 on rod 199. Shear pins (not shown) can be inserted
through
apertures,201 into holes 202 to releasably lock rod 199 against slidable
nwvement in
bore 200. Other releasably lockable means can be used in place of shear pins
such
as spring biased pins or a locking collet. A releasable locking means which
can be
repeated locked and unlocked is preferred where the tool is to be.repeatedly
used
downhole without being brought back to surface.
Rod 199 extends out of housing 174 and end 199" opposite end 199' is retained
in a
bore 204 formed in a lower housing 206. A portion of end 199" is enlarged so
that rod
is retained in the bore. End 199" and bore 204 are similarly faceted to
prevent rotation
of rod 199 in the bore. However, bore 204 Is selected to have a gnsater inner
diameter.
IDb, than the width, w, of end 199" so that rod 199 can move laterally within
bore 204.
This forms a wobble shaft arrangment and provides that housing section 206 can
move
out of axial alignment with axis 178 of housing 174.
Housing 2d6 houses an orienting assembly including a plurality of orienting
dogs 208.
Preferably there are four orienting dogs spaced apart 90 degrees aligned
around a
circumference of the housing. Dogs 208 are retained in housing in any suitable
way
such as by abutfing flanges, not shown. Dogs 208 are biased outwardly by
springs
210, such as Belleville washers, which are actuated to apply.various,
selectable
degrees of force to the dogs. Springs 210 are actuated to vary their biasing
fome by
a hydrostatic piston assembly 212. In particular, piston 212 includes a piston
214
having a face 214' in communication with a chamber 216 opening though aperture
218
to the exterior of the tool. Opposite face 214" of the piston is open to
chamber 219
selected to be at a pressure generally corresponding to ground surface
ahnospheric
CA 02527161 2008-03-25
79350-180D
pressure. Piston 214 is drivingly connected to rod 220 and
rod cup 222. Upper end 222' of rod cup 222 is drivingly
connected to springs 210.
As the pressure in chamber 216 increases relative
5 to the pressure in chamber 219, piston 214 will be driven
to drive rod 220 and rod cup 222 to compress springs 210.
It will be readily understood that movement of the rod cup
varies the pressure applied to the springs and thereby the
pressure at which dogs 208 are biased outwardly from
10 housing 204. Prefexably, at maximum compression springs
210 are selected to bias dogs 208 outwardly at a pressure
of 20,000 to 30,000 psi and preferably 25,000 psi. The
springs can be replaced with other biasing means such as a
hydraulic means which is acted upon by the hydrostatic
15 piston. In addition, the assembly can be selected to act
on dogs from both the bottom side and the top side or just
from one side, as shown.
Where greater load is required 'to be applied to
the dogs, additional hydrostatic pistons can be added in
20 series.
The lower sections of Figures 6A-6B are useful
with a casing section 224 as shown in Figure 7A to 7C. To
fully understand the operation of lower section 22' to
orient and lock a toolgui.de into position, we must first
review the structure of the casing section. Because of the
length of casing section 224, it has been separated into
three views. Figure 7A shows the lower portion of the
casing section, Figure 7B shows the middle portion of Che
casing section and Figure 7C shows
CA 02527161 2008-06-19
79350-180D
20a
the upper portion of the casing section. For ease of
production and handling, the casing section can be produced
in separate sections, as shown, for connection together.
Alternately, the casing section can be formed as one piece.
Casing section 224 is used with other sections, such as
those indicated as sections 6 in Figure 1 to form a casing
string. Casing sections 6 can be connected below the
section by threaded engagement to pin end 224' in Figure 7A
and casing sections can be connected above casing section
224 by threaded connection to box end 224 in Figure 7C.
Casing section 224 includes a window opening 112
which is sized and shaped to permit
CA 02527161 1998-08-18
~
21
directional drilling therethrough. Casing section retains therein a sleeve 123
as will be
described hereinafter.
A radial profile 230 is formed at a selected distance below window 112. Radial
profile
230 is selected to have a length Lp greater than the axial length Ld of dogs
208 (Figure
6) so that dogs 208 can be accommodated in profile 230. Casing section also
includes
a latch receiving siat 16a formed a selected distance below and a selected
radial
orientation from window 112. Preferably, latch receiving slot 16a is
positioned directly
below the window for ease of manufacture. Latch receiving slot 16a is selected
to be
of a size to accommodate the face of latch 20'.
In use a toolguide including lower section 22' and upper section 24' is run
into a casing
string including section 224. The lower section is selected such that both the
diameter
across dogs 208, when they are fully extended, and the diameter of the tool
across
seals 28, will be greater than the diameter of the casing. Since dogs 208 are
biased
outwardly, dogs will engage against the surface of the casing.
A running tool is connected to upper section and the weight of the tool guide
is
supported on running tool. At surface, the tool is in the relaxed, unset
position (not
shown). In particular, the shear pins are inserted through apertures 201 into
holes 202
which locks housing 174 down in close position to housing 206 and maintains
end 199'
in cavity 193 to retain latch 20' in a recessed position. To maintain this
configuration
during handling, the shear pins at this connection are selected support the
weight of the
housing 206 and its components. No weight of the upper section is applied at
locking
collet 177 and therefore substantially no engagement is made between the
locking
collet and portion 177a. Finally, the pressure in chamber 216 is generally
equal to the
pressure in chamber 219. Thus, piston is equalized and substantially no
pressure is
applied at springs 210 of dogs 208. Dogs 208 are therefore biased outwardly a
minimum selected pressure, for example, 0 to 500 psi and are capable of being
driven
inwardly to move into and along the casing string.
CA 02527161 1998-08-18
22
As tool is being run into the casing string, the hydrostatic pressure of the
fluids in the
well will increase as the depth of the tool increases. As the pressure
increases of the
well fluids increase, the pressure in chamber 216 increases causing piston 214
to be
driven into chamber 219, which is at a lower pressure. Movement of piston is
translated
to rod 220 which, though rod cup 222, compresses springs 210. Compression of
springs 210 drives dogs 208 outwardly at increased pressures until maximum
pressure
is reached. When maximum pressure is reached the weight of the running string
is
sufficient to drive the tool through the casing string. However, the pressure
in dogs is
selected such that it will affect the load required to move the tool though
the casing. In
one embodiment, the maximum biasing pressure on dogs is selected to be about
20,000 to 30,000 psi. Preferably, the leading, lower edges 208' of the dogs is
sloped
to facilitate movement of the dogs over raised or recessed portions of the
casing string.
It will be appreciated that, because of the alignment of the dogs about a
circumference
of the lower section and the pressure acting on the dogs, it will be
determinable when
the dogs have passed from the standard casing diameter over or into a radial
form in
the casing. Preferably, the trailing, upper edge 208" is selected to be square
or only
slightly sloped to engage more firmly against raised shoulders in the casing.
Thus, to
ensure that the dogs are located in profile 230, the tooiguide can be puiled
up while
monitoring the force on the running string to confirm that the dogs have
engaged
against the upper shoulder of the profile. Preferably, no other radially
recessed areas
in the casing are of a size to permit dogs 208 to drop therein. Thus, tool
orientation
along the length of the casing string can be determined by monitoring the
force applied
to the running string to determine when the dogs are located in profiie 230.
During use
of the tooiguide in a horizontal section of well, the housing 206 can move
laterally, at
connection of rod 199 in bore 204, out of alignment with the remainder of the
tool. This
prevents the dogs from being acted upon by the entire weight of the string.
During confirmation of dog orientation, sufficient pressure will be applied to
the string
in a upward (toward upper section) direction, that shear pins in apertures 201
will shear
(i.e. at 5,000 psi) and housing 174 will be pulied along rod 199 away from
housing 206.
CA 02527161 2008-03-25
79350-180D
23
This will cause end 199' to be pulled out of
cavity 193. The pressure of springs 186 behind latch 20,
drives latch 20' outwardly. Since cavity 193 will then be
out of alignment with rod end 199', engagement cannot be
made again between latoh 20' and rod 199, even where force
is again applied toward the lower section.
The distance between latch 20' and dogs 208 is
selected to be generally equal to the distance between
profile 230 and latch receiving slot 16a so that when latch
is biased outwardly it will be at the same position along
the casing as the slot 16a. Thus, by rotation of the tool,
latch 20' can drop into slot 16a. in this configuration
sloping face 26' of upper section 29' will be oriented to
direct tools moved along it, laterally outwardly toward
window 112.
When the running tool is removed from the upper
section, the weight of the upper section will be pushed
down or set down on the lowar section causing tube 179 to
force seal 28 to expand outwardly and to cause extensions
198 of mandrel to move into cavity 192 to lock latch 20' in
outwardly extended position. Also when the weight of the
upper section is set down on the lower section, locking
collet 177 will be driven by its spring to engage against
the knurled portion 177a of mandrel.
Referring to Figure 9, another casing section 108
according to the present invention is shown. Casing
section 108 is useful in the drilling and completion of
deviated well bores. It is used attached to other casing
CA 02527161 2008-03-25
79350-180D
24
sections such as those indicated as sections 6 in Figure i
to form a casing string.
Casing section 108 includes a window opening 112
and a sleeve 123. Casing section 108 has a known internal
diameter, indicated at IDc. A cylindrical section is
removed from the inner surface of the casing to form a
groove 119 which has a larger inner diameter than the
casing. A key 121 is secured, as by welding, in the groove
adjacent its bottom edge.
Sleeve 123 is disposed in groove 119. An
embodiment of the sleeve for use in the embodiment of
Figure 9 is shown in flattened configuration in Figure 10.
To ready the sleeve shown in Figure 10 for use, sides 123a,
123b of the sleeve are brought together and preferably
attached, as by welding.
Sleeve 123 has a key slot 125 at its lower edge
to engage key 121. Key slot 125 has two locking slots 125a
and 125al and a ramped portion 125b therebetween to
facilitate movement of key 121 between slots 125a, 125ai.
Sleeve 123 is rotatable and longitudinally moveable in
groove 119 and key siot 125 is formed to limit the movement
of sleeve 123 over key 121 between a first position at
looking slot 125a and a second position at locking slot
125a1. Sleeve 123 is selected to have an inner diameter IDs
which is greatier than or equal to the inner diameter IDc of
casing 108.
Sleeve 123 has a first opening 127 which is
larger than window opening 112 but is positioned on the
CA 02527161 2008-06-19
79350-180D
sleeve such that it can be aligned over window opening 112.
Sleeve 123 preferably also has a second opening 129 which
is substantially equal to or smaller than window opening
112. Second opening 129 is shown spaced about 180 degrees
5 from opening 127 in Figures 7A to 7C, while in Figure 9
opening 129 is rotated only about 80 degrees from first
opening 127. Second opening 129 is also positioned on
sleeve 123 such that it can be aligned over window opening
112. Key slot 125 is shaped relative to key 121 to permit
10 movement of the sleeve to align one of the first and second
openings 127, 129 over window opening 112 and locking slots
125a, 125a' are positioned to lock the sleeve by its weight
at these aligned positions.
Seals 131 are provided at the upper and lower
15 limits of the sleeve between the sleeve and groove 119. In
the embodiment of Figure 10, seals 133, 135 are also
provided about openings 127 and 129, respectively. Seals
131, 133, 135 are each formed of materials which are
hydraulically sealed such as o-rings positioned in
20 retaining grooves or lines of vulcanized polymers such as
urethane. Preferably, the seating areas for the seals are
treated, for example by machining to provide a smooth
surface, to enhance the sealing properties of the seals.
The seals act against the passage of fluids between the
25 sleeve and the structure to which they are seated, for
example the casing or the flange of a tieback hanger. In
an alternate embodiment, the seals are secured to the
casing and the sleeve rides over them.
CA 02527161 2008-03-25
79350-180D
25a
In the embodiment of Figure 10, an aperture 137
is provided on the sleeve which is sized to accept, and
engage releasably latches on a shifting tool (not shown).
The latches of the shifting tool hook into apertures 137 on
sleeve 123 and shift tool is raised to pull the sleeve
upwardly to release key 121 from locking slot 125a or 125a1
into which the key is locked. The shifting tool then
rotates sleeve 123 within groove 119.
The sleeve can be shifted by other means such as
a sleeve shifting tool, as will be described in more detail
hereinafter, having pads with teeth formed thereon for
being forced against the sleeve material so that the sleeve
can be rotated in the groove.
Window opening 112 has a profiled edge 113. Edge
113 is formed to accommodate and retain a flange 115
(Figure 11A) formed on a deviated wellbore liner or tieback
hanger 117.
In use, casing section 108 having sleeve 123
disposed therein is prepared for placement downhole by
aligning opening 127 over window 112. To prevent
inadvertent rotation of sleeve 123 in its groove, shear
pins 138 are inserted to act between the sleeve and the
casing section. A liner is then inserted through the
internal diameter and opening 112 is filled and wrapped, as
discussed with respect to Figure 2. A casing string is
formed by attaching casing section 108 to other casing
sections selected from those which have window openings or
those which are standard casing sections. The casing
CA 02527161 2008-03-25
79350-180D
25b
string is then inserted into the wellbore and is aligned,
as desired. The wellbore is then completed.
After completion, the hardened cement and the
liner are removed from the casing string. This exposes
sleeve 123 within casing section 108. A toolguide, for
example, according to Figure 1 or any other toolguide, is
positioned in the well such that the face of its upper
section is opposite opening 112 and a deviated wellbore is
drilled.
CA 02527161 1998-08-18
26
Once the deviated wellbore is drilled, at least a junction fitting such as a
tieback hanger
117 is run into the well and positioned such that its flange 115 is engaged on
edge 113.
Sleeve 123 is then lifted and rotated by engaging the setting tool in
apertures 137 such
that opening 129 is aligned, over opening 112 and thereby the central opening
of the
tieback hanger. This causes seals 135 to seal against flange 115 and prevents
fluids
from outside the deviated casing from entering into casing section 108 at the
junction.
Using the sleeve of the present invention, the deviated wellbore does not need
to be
completed using cement to seal against passage of fluids outside the casing.
However,
where desired, the deviated wellbore can be completed using cement to increase
the
pressure rating of the seal.
The sleeves according to the present invention can be rotated using any
suitable tool.
A tool which engages in apertures 137 can be used or alternately a sleeve
shifting tool
450 can be used as shown in Figures 16A and 16B which does not require the
alignment of dogs into apertures but rather frictionally engages the sleeve.
In particular,
tool 450 is sized to be insertable into the inner bore of the casing and
sleeve and
includes an elongate body 452. A plurality of sleeve engaging slips 454a, 454b
are
mounted in the body to be moveable radially inwardly and outwardly between a
retracted position (i.e. 454a') and an extended position (i.e. 454b'). In the
extended
position, the slips 454a, 454b are selected to frictionally engage against the
sleeve with
sufficient force to permit lifting and rotating of the sleeve.
Preferably, the sleeve engaging slips are selectively positioned along the
tool so that
they will engage the sleeve adjacent the upper and lower edges thereof and at
a
plurality of positions about the inner radius. The sleeve engaging slips can
be formed
in any suitable way to engage against the sleeve. In one embodiment, the
sleeve
engaging faces 455 of the slips are roughened or knurled or have teeth formed
th ereon
in a suitable way to permit the slips to bite into the material of the sleeve.
In the
illustrated embodiment, slips are provided in two orientations. Slips 454a are
selected
to enhance frictional engagement to provide for longitudinal movement (le.
lifting) of the
sleeve and slips 454b are selected to enhance frictional engagement to provide
for
CA 02527161 1998-08-18
27
rotational movement of the sleeve. In particular, slips 454a include elongate
teeth 456a
formed orthogonal to the long axis 452x of the body 452 and slips 454b include
elongate teeth 456b formed substantially parallel to long axis 452x.
Preferably the teeth
456a, 456b are formed with leading edges formed to define acute angle so that
they
exhibit enhanced frictional engagement in one direction.
Sleeve engaging slips 454a, 454b can be moved radially inwardly and outwardly
between the retracted position and the extended position in any suitable way.
In the
illustrated embodiment, the slips 454a, 454b are moveable by changes in fluid
pressure
as controlled from surface. In particular, body 452 is formed as a tube having
an inner
bore 458 closed at one end 452a by a plug 458b. Body 452 is connected at
opposite
end 452b to a tubing string 459 extending upwardly toward surface such that
bore 458
can be pressured up by feeding a fluid from surface through tubing string 459_
Stips 454a, 454b are mounted in ports 460 to be radially slidable therein
relative to the
long axis of the tool. The outer diameter of the slips conform closely to the
inner
diameter of the ports so that resistance is provided to fluids passing
therebetween.
0-rings 463 are provided about the slips to form a seal between ports 460 and
slips
454a, 454b. Ports 460 open into bore 458 to be in communication therewith and
open
to the outer surface 452' of body 452. Ports 460 have a reduced diameter at
portion
460' to prevent slips 454a, 454b from dropping into bore 458 and straps 464
are
mounted, as by use of fasteners orweldments, across ports adjacent outer
surface 452'
to hold the slips in the ports. Slips 454a, 454b each include a slot 466
extending across
the engaging face thereof to accept strap 464. Slot 466 permits the engaging
face of
the pad to extend out beyond strap. As will be appreciated, strap 464 also
prevents the
rotation of the slips within the ports, thereby preventing the teeth from
rotating out of
their selected orientation. Springs 467 are provided between the straps and
the slot
466 to bias the slips inwardly. Preferably, straps 464 are not intended to
hold the slips
in the ports against fluid pressure behind the slips. Instead, the tool is
intended only to
be pressurized while within a member such as the casing which prevents the
slips from
extending to bear against the straps.
CA 02527161 1998-08-18
28
Although Figure 16B appears to show that a plurality of slips are positioned
in close
proximity about the tool, preferably there are two to four slips 454a
positioned at each
of the top and the bottom of the tool. In each position, these slips are
equally spaced
apart around the circumference. The same arrangement is selected for the slips
454b.
As noted above, the slips 454a, 454b are moveable by changes in fluid pressure
in
bore. In use, when the pressure of the fluid in bore 458 is increased relative
to the
pressure about the tool, slips 454a, 454b are driven outwardly through ports
460
against the tension in springs 467 and into extended position until the slips
engage
against the sleeve. If a sufficiently high pressure is provided to the bore,
the slips will
bite into the sleeve with a frictional engagement sufficient to move the
sleeve by
movement of the tool, as by movement from surface. If the pressure is
maintained, the
slips will remain in the extended position. If the pressure is lowered, to a
pressure
relatively equal to or less than the ambient pressure around the tool, the
slips wili be
retractable and will not maintain a frictional engagement with sleeve which is
sufficient
to move the sleeve by movement of the tool.
To assist in the pressurization of the bore, a check valve 468 is provided
adjacent end
452b, either in the bore of the tubing string 459, as shown, or in bore 458 of
body 452
above the upper set of slips. Check valve 468 permits the flow of fluid behind
slips
454a, 454b, but substantially prevents fluid from passing upwardly out of bore
458.
Thus, pressure can be maintained behind the slips to maintain them in an
extended
position without maintaining the pressure in the entire tubing string to
surface. When
check valve 468 is used, a means for releasing the pressure from within the
bore is
required in order to permit the tool to be disengaged from the sleeve, once
the sleeve
has been shifted. As an example, valve 468 can be mechanicaliy or electrically
openable or a vent can be provided. In the illustrated embodiment, plug 458b
is
burstable by application of pressure greater than a selected value. Therefore,
when it
is desirable to release the tool from engagement with the sleeve, further
fluid pressure
is forced into bore 458 through check valve 468 until plug 458b bursts
allowing
CA 02527161 2008-03-25
79350-180D
29
equalization between -r-he bore pressure and the pressure
about the tool.
To permit proper positioning of the tool at the
location of the sleeve in the well bore, a wobble shaft
arrangement 470 and an orienting assembly 471, as discussed
hereinabove with respect to Figures 6A-6B, can be used.
The sleeve according to the present invention can
be modified to permit other uses. For example, a sleeve
can be used which has one or two openings which can be
aligned with window opening and can also be positioned to
block a window opening. Referring to Figure 12, one
embodiment of such a sleeve is shown. Sleeve 223 is shown
in flattened configuration and when readied for insertion
into a groove of a casing section sides 223a, 223b are
brought together. A key slot 225 is formed at the lower
edge of sleeve 223 for riding over a key formed in the
groove of the casing section in which the sleeve is to be
used. Key slot 225 has three locking slots 225a, 225a' and
225a" to permit sleeve 223 to be moved between three
positions. The first position of which is where the key is
locked, by the weight of the sleeve, into slot 225a and
opening 127 is aligned with the window opening of the
casing section. The second position is ehat in which the
key is locked into slot 225a' and opening 129 is disposed
over the casing window opening. The third position is the
one in which the key is locked into slot 225a" and a solid
portion of the sleeve indicated in phantom at 234, is
disposed to block off the window opening of the casing
section_ The sleeve can be moved between any of these
CA 02527161 2008-03-25
79350-1800
positions by a shifti.ng tool. The groove into which the
sleeve is mounLed is formed to accommodate such movement.
Seals 233, 235 are provided around Qpenings 127,
129 and seals 231 are provided around the upper and lower
5 regions of sleeve 223 to hydraulically seal between the
sleeve and the casing into which the sleeve is mounted.
The seals are on the other side of the sleeve and are shown
in phantom in this view.
Referring to Figure 11B, generally the tieback
10 flanges are tormed as tabs 115' and are disposed on the
tieback 117 to extend out from rhe sides thereof.
Generally, there can be two tabs 115', as shown, or four
tabs 255 shown in phantom. Hecause of the arrangement of
the tabs, ithas been difficult or impossible to use a
15 liner having an outer diameter just less than the inner
diameter of the casing through which it is to be run. In
particular, in such an arrangement, the casing window is so
large across its width that the flange tabs have nothing to
latch against.
20 Referring to Figure ].1C, a tieback hanger 117'
has been invented wh3.ch is useful for use in tying back a
liner having an ou=L-er diameter close to that of the casing
inner diameter. Tieback hanger 117' has flanges 252
positioned at the top and bottom of its open face 254.
25 Tieback hanger 117' is intended to be used with a
casing section, such as that shown in Figures 7A to 7C aind
in Figure 13 (13a, 13b), having a wall 256a extending out
into window 112 adjacent the top thereof and another
CA 02527161 2008-03-25
79350-180D
31
wall 256b extending out at the bottom of the window, Walls
256a, 256b provide surfaces against which flanges 252 can
latch. Walls 256a, 256b are recessed relative to the inner
surface of casing sec-tion 224, so that when flanges 252
latch against the walls, sleeve 123 can be rotated over the
open face 254 of the tieback hanger to hydraulically seal
off the liner. In this embodiment, preferably, the open
face 254 of the tieback hanger has bonded thereto, as by
vulcanization, a polymeric material 258 such as, for
example, urethane to seal against the sleeve.
Walls 256a, 256b can be partial or complete.
Preferably the walls are disposed at the top and bottom of
the window and form a V-shaped opening. The walls can be
formed integral with the casing section 224 or can be
attached, as by welding, to the outside of the casing
section.
The tools disclosed herein must be run into and
retrieved from the well. Running and retrieval tools are
knawn. However, previous running and retrieval tools are
sometimes difficult to manipulate and operate. These
previous tools are particularly difficult to operate in
horizontal runs of casing.
A new tool 270 which can be used for both run in
and retrieval of whipstocks is shown in Figure 8 (8a, 8b).
Tool 270 is in'tended for use with a whipstock as shown in
Figures 4A and 4B and a casing section as shown in Figures
7A to 7C. To facilitate undersranding of the tool 270
reference should be made to those Figures.
CA 02527161 2008-06-19
79350-180D
31a
Tool 270 includes a front end 270' and a threaded
end 270" for connection to a drill pipe, such as that shown
as 32 in Figure 1. A bore 272 extends a portion of the
length of the tool and opens at end 270". A piston 274 is
disposed to move slidably along a length of bore between
shoulders 276, 277 and a spring 280 is disposed between
piston 274 and an end wall 284 of bore 272 to bias piston
outwardly against shoulder 276. A rod 286 is connected to
piston 274 and is driven thereby. Rod 286 extends through
a channel 287 extending from bore 272 and has a tapered end
286'. Preferably, rod 286 is bifurcated to form two arms,
each with a tapered end.
Tool 270 houses a latch assembly including a
latch 288, a latch retaining plate 290 and a plurality of
springs 292 acting between the latch 288 and the plate 290
to bias the latch radially outwardly from the tool. Of
course, the plate can be replaced with an end wall formed
integral with the body of the tool. However, a plate is
preferred for ease of manufacture. Latch 288 is retained
in a channel 294 through tool 270. Latch 288 can be
recessed into channel 294 by application of force
sufficient to overcome the tension in springs 292 on the
latch toward plate 290. Latch 288 is prevented from being
forced by the action of springs 292 out of the channel, by
abutting against end 286' of rod 286 which extends into
channel. In particular, latch 288 has a ramped surface 296
over which tapered end 286' can ride.
Movement of rod 286 through channel 287, by
movement of piston, causes latch 288 to be moved radially
inward and outward in tool, by movement of tapered end 286'
CA 02527161 2008-03-25
79354-1BOD
31b
over ramped surface 296. Thus, by controlling the pressure
acting on piston face 274', latch 288 can be selectively
moved.
Latch 288 is formed to fit into a slot, suah as
slot 55 on upper section 24' of Figure 4A.
CA 02527161 1998-08-18
32
Latch has a ramped surface 300 on its front edge, to ease the movement of the
latch
over protrusions. A reverse angle portion 302 is provided on the rear edge of
the latch
which acts as a catch to resist against the latch moving out of the slot by
any force
applied toward end 270".
Tool 270 further includes a orienting key 304 retained in cavity 305. Key 304
is biased
radially outwardly from the tool by means of springs 306 acting between the
key and
an end wall 305a of cavity 305. Key 304 is prevented from being forced out of
cavity
305 by shoulders 308. Key 304 is selected to fit into an orienting slot on a
casing
section, such as slot 309 in casing section 224.
Tool 270 has formed thereon a dove-tailed rail 310. Rail 310 is selected to
fit into a
dove-tail slot on a whipstock, such as that indicated as slot 51 in Figure 4A.
Rai1310
is oriented relative to latch 288 with consideration as to the orientation of
slots 51 and
55 on the whipstock with which the tool is to be used. Rail 310 is spaced from
latch 288
a selected distance which corresponds to the distance between slot 55 and 51
on the
whipstock. Preferably, rail 310 is formed to be in longitudinal alignment with
latch 288.
Rail 310 is oriented on the tool relative to key 304, with consideration as to
the
orientation which slot 309 has relative to a slot 51, when a whipstock is
mounted in the
casing section. In the illustrated embodiment, slot 309 is longitudinally
aligned with
window. Thus, when a whipstock is mounted in the casing section, the sloping
face of
the whipstock will be positioned opposite the window and slot 309 and in the
illustrated
embodiment rail 310 is spaced 180 degrees from key 304.
Another key 312 is preferably provided on the tool and spaced 180 degrees from
rail
310. Key 312 rides in a port 314 opening between the outer surface of the tool
and
bore 272. Key 312 can be moved along a portion of the port 314 as limited by
shoulders 316a, 316b.
Too1270 preferably includes a first fluid delivery port 318 extending between
bore 272
and an end 310' of rail 310. A second fluid delivery port 320 extends between
bore 272
CA 02527161 1998-08-18
33
and a position adjacent latch 288.
In use in a running operation, tool 270 is attached to whipstock 24' at
surface. This is
done by advancing the tool toward the whipstock so that rail 310 is inserted
into slot 51.
This requires that latch 288 be forced into channel 294 by any suitable means.
When
rail 310 is fully inserted in slot 51, latch 288 will engage in slot 55. A
drill pipe is
attached at end 270". Latch 288 is maintained in slot by action of springs
292.
Tool 270, with whipstock 24' attached, is then run into the well on the drill
pipe. When
whipstock is properly mounted in the casing, whipstock is released from the
whipstock
by applying pressure against the piston to drive rod 286 through channel 287
to,
thereby, drive latch 288 into a recessed position in the tool. Pressure can be
applied
to the piston, for example, by forcing a drilling fluid, such as mud, through
drill pipe into.
bore 272. Application of drilling mud increases the pressure in the bore and
drives
piston against spring 280, which in tum drives rod 286 to advance against
latch 288.
When latch 288 is removed from slot 55, rail 310 can be removed from slot 51.
Tool
270 is then free to be returned to surface.
To use tool 270 in a retrieval operation, the tool is run in on a drill pipe
until it runs into
the whipstock. The tool is then pulled out a short distance and is rotated
until key 304
drops into slot 309. Because the orientation of slot 309 with respect to a
whipstock
mounted in the casing section is selected to correspond to the location of the
key 304
with respect to rail 310, the rail will be aligned with slot 51 of the
whipstock when key
304 is engaged in its slot 309.
Pressure is then applied to piston, such as by pressuring up the drill string,
to retract
latch 288 so that the tool can thus be advanced to insert rail 310 in slot 51.
Applying
fluids to bore 272 also serves to cause fluid to be passed through and out
ports 318 and
320 at high pressures to clean out slots 51 and 55 which may be filled with
debris.
Pressure in bore 272 also acts against key 312 to cause it to be driven
radially
CA 02527161 1998-08-18
34
outwardly from the tool. This causes the rail to be driven toward the casing
wall. Key
312 is particularly useful when the tool is used in horizontal runs of casing.
In horizontal
wells, the whipstock is sometimes mounted against the upper side of the
casing, as
determined by gravity. When the tool is used to latch onto the whipstock, the
weight
of the tool and dri8 pipe will cause key 304 to be driven into cavity 305.
Thus, rail is out
of position for insertion into slot and will simply ride under the sloping
face of the
whipstock. Key 312 can then be used to raise the tool toward the upper side of
the well
casing so that rail 310 can align with slot 51.
When rail 310 is inserted fully into slot 51, the drill pipe can be
depressurized to permit
the iatch to be biased outwardly into slot 55. Tool 270, with whipstock 24',
attached can
then be retrieved back to surface.
When rail 310 and latch 288 are engaged in their respective slots on the
whipstock, all
forces, either longitudinal or torsional, which are applied to the tool are
directly
transmitted to the whipstock. The tool 270 permits both run in and retrieval
and is
useful in horizontal well sections.
To facilitate use of the tools and the casing sections described herein and
others not
herein described, preferably a high side tool is used. To facilitate use of
the high side
tool, preferably sensors such as, for example, magnetic sensors, are mounted
in the
tools andlor the casing section components (ie. the sleeve), for reading by
the high side
tool. The sensors are preferably mounted so that it can be determined both (a)
where
the high side, according to gravity, is and (b) the degree to which any well
component
has been rotated.
Another problem which occurs in downhole assembly manipulation is the
orientation of
the tieback hanger in proper position for insertion through the window.
Previous tools
actuate the tieback hanger and liner too slowly and therefore increase the
chances of
the liner being stuck against a negative pressure formation.
CA 02527161 1998-08-18
lqw
Referring to Figure 14, a tool 330 has been invented which useful for downhole
placement and positioning of tieback hangers. Tool 330 includes a housing 332
with a
bore 334 extending therethrough. Slidably positioned in bore 334 is a rod 336.
Rod
336 and bore 334 are similarly faceted at least along a portion of their
lengths so that
5 rod 336 is substantially prevented from rotating in the bore. Rod 336 has a
box end
336' for connection to a drill pipe (not shown). Box end 336' acts to limit
the sliding
movement of rod 336 through bore 334 by abutment against housing 332.
At its opposite end 336", the rod has formed thereon threads 338 for
connection to a
flex shaft which extends into a whipstock and bends along the face thereof for
10 connection to a hydraulic liner running and setting tool, as are known (not
shown). A
shoulder 340 is formed to abut against the end of the flex shaft, when the
flex shaft is
engaged on the rod.
Housing supports a collet 341, a key 342 and a poppet 343. Colieit 341
includes a
plurality of (ie. four) circumferentially aligned dogs 344. Dogs 344 are
biased radially
15 outwardly by springs 345 and are selected to locate in a profile formed in
a casing
section (not shown) for use with the tool. Preferably, the profile is a radial
groove to
avoid having to properly orient the dogs to drop into the profile and to
thereby ease
location of dogs 344 therein.
Key 342 is biased radially outwardly from housing by springs 346 but is
secured in the
20 housing by walls 348. Rearwardly extending arms 347 extend from key 342
into bore.
Cavtties 348 are formed in rod 336 to accept arms 347, when they are aligned.
When
key 342 is recessed into cavities, rod 336 is prevented from sliding movement
through
bore 334. The diameter of the tool at key 342, when the key is fully extended
is
selected to be greater than the diameter of the casing in which the tool is to
be used.
25 This provides that when the tool is located in the casing, the key will be
forced against
the tension in springs 346 into the housing. Key 342 has chamfered ends 342'
to
facilitate riding over protrusions. The sides of key 342 (which cannot be
seen) have
substantially no chamfer to be square or to form a reverse angle so that they
will tend
CA 02527161 1998-08-18
36
to catch on protrusions in the casing. The key is formed to fit into an
orienting slot on
the casing section in which it is to be used. When whipstock is connected
through the
flex shaft to tool 330, the whipstock face is positioned in a selected
orientation relative
to key 342. The selected orientation will depend on the orientation of the
slot for key
342 relative to the window opening in the casing.
Poppett 343 is positioned in a hole 349 opening into bore 334 and is biased
into the
bore by a spring 350. A cavity 351 is formed on shaft 336 for accepting head
343' of
the poppett, when the head and the cavity are aligned. When poppett 343 is
positioned
in cavity 351, shaft 336 is prevented from sliding movement within bore 334. A
seal 352
disposed about poppet 343 forms a chamber 354. The pressure in chamber 354 is
selected to be a level near surface pressure. A port 356 extends from the
exterior of
the tool either along shaft 336, as shown, or along housing to open adjacent
head 343'.
Tool is used to rapidly position a tieback hanger for proper placement in the
window to
affect latching of the tieback flange against the window. In use, at surface
tool is
connected at end 336" to a flex shaft which has attached thereto a tieback
hanger and
a hydraulic liner running tool. Housing 332 is moved along rod 336 until
poppet 343
snaps into cavity 351. A drill pipe (not shown) is aitached at end 336' and
the tool with
attachments is inserted into the well.
In the casing, dogs 344 ride along the inner surface of the casing and key 342
is driven
inwardly so that arms 347 engage in cavities 348. As the tool run further into
the well,
the hydrostatic pressure in the well will be communicated to head 343' of the
poppet
through port 356. As the hydrostatic pressure increases, poppet will be driven
back into
chamber 354 and out of engagement with rod 336. This will release the full
weight of
the rod and attachments onto key 342. Rod will remain in fixed position
relative to
housing, however, because of arms 347.
The tool is run to a depth such that dogs 344 drop into their profile in the
casing. When
the dogs are located in their profile, the key will be positioned at the
appropriate level
CA 02527161 1998-08-18
37
to engage in its slot and the tool need only be rotated to locate key 342 in
its slot.
When key 342 locates in its slot, springs 346 drive arms 347 out of cavities
348 and rod
336 will immediately slide through bore 334 in response to the weight of the
attached
tieback hanger and other attachments. Because of the fixed orientation of key
342
relative to the tieback hanger face and the fixed orientation of the key's
slot relative to
the casing window, the tieback hanger will be advanced through the casing and
the
window in proper position for latching the flanges onto the window edge. The
liner can
then be manipulated using the hydraulic liner running tool.
It will be appreciated therefore that this tool is particularly useful in
placement of a
tieback hanger. The liner remains stationary only long enough for the toot to
be rotated
to located key 342 in its slot. This is a great reduction in liner stationary
time over
previous tools and prevents liner lock up against negative pressure
formations.
The tools for formation and completion of deviated wells, as described
hereinbefore and
other not specifically described herein, require manipulation by rotation of
the tool. In
deep well operation and particularly in horizontal well applications, it is
virtually
impossible to rotate the tool by manipulation from surface.
Referring to Figure 15, according to one aspect of the present invention, a
motor 400
for imparting rotational drive such as, for example, a mud motor is connected
at an end
of a drill pipe 32' adjacent the tool 402 or well component to be rotated. The
motor is
connected to the drill pipe such that when the motor is driven, rotational
force will be
communicated to the drill pipe to cause it to rotate within the casing.
Preferably, the motor is driven by pumping drilling fluid therethrough. The
motor is
preferably a high torque, low speed motor which is selected to stall when the
load
thereon exceeds a selected level. In particular, when, for example, a tool is
to be
rotated until a latch drops into a slot, the motor will have a selected power
to drive the
drill pipe to rotate but when the latch is positioned in the slot and the load
increases, the
motor will stall to cease rotation of the drill string.
CA 02527161 2008-06-19
79350-180D
38
In an embodiment, where hydraulic pressure is
required below the motor, such as for example, where the
tool 402 is like tool 270 of Figure 8, a bypass valve 404
is positioned above motor 400 to permit flow through a
bypass port 406 passing without effect through motor and
extending towards tool 402.
Figure 11C, showed a tieback hanger which is
useful for tying back a liner having an outer diameter
close to that of the casing inner diameter. Figures 17 to
19B show another tieback hanger 500 and casing 502
arrangement which is similarly useful but avoids increasing
the OD or decreasing the ID of the casing at the window
opening.
Tieback hanger 500 is intended to be used with a
casing 502, such as that shown in Figures 17 to 17B, having
a window opening 504 formed therethrough. The casing wall
edges 505 defining the window opening include profiled
areas 506, 508 formed from the thickness of the casing wall
material which extend inwardly over the window opening.
Preferably, the profiled areas are formed to extend from
the outer surface of the casing and to substantially follow
the circumferential curvature of the casing outer wall.
Preferably, the profiled areas are formed to taper
gradually toward their edges so that a beveled edge is
formed. The profiled areas can be formed to extend at
selected positions around the window opening or about the
entirety thereof. In the illustrated embodiment, profiled
areas 506 are formed adjacent the bottom of window opening
504 and profiled areas 508 are formed adjacent the upper
end of the window opening.
CA 02527161 2008-03-25
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38a
Tieback hanger 500 includes a sleeve 510
zncluding an outboard end 512 for connection to a lateral
liner (not shown) and an anchored end 514 for connection to
casing. End 514 has a lower setting tab 516 and an upper
setting tab 518 formed to engage against the profiled areas
506,508 formed about window opening 504. Setting tabs 516,
518 are formed to flare outwardly adjacent the edge of end
514 and to mate with the profiled areas 506, 508. Setting
tab 516 forms a tapering dove-tail configuration, as best
seen in Figures 18 and 18A, which can be wedged between
profiled areas 506 which form a tapering dovetail mortise,
as best seen in Figures 17 and 17A. This prevents the tie
back from being pushed entirely out of the window
CA 02527161 1998-08-18
39
during setting. Upper setting tab 518 is also flared to form a dovetail, as
best seen in
Figure 19A, which can be wedged against profiled areas 508. The thickness of
setting
tabs 516, 518 is preferably selected such that the end 514 substantially abuts
against
the outer surface of the casing, while the setting tabs substantially do not
extend
inwardly beyond the inner surface of the casing. This selected thickness
provides that
a minimum amount of material is added to the OD of the liner tieback.
When setting tabs 516, 518 are engaged against corresponding profiled areas
506,
508, tieback hanger will extend through the window opening and hang off from
the
casing.
in some wells, the laterals extend from the main well bore in such a way that
the liner
tieback can drop back into the casing and obstruct the passage of tools
through the
main well bore and into the lateral. In one embodiment as shown, the tieback
hanger
can be prevented from dropping into the casing by forming the edges of the
window
opening to engage the end of the tieback hanger against both passing through
the
window opening both outwardly and inwardly into the casing bore. The edges of
the
window opening can be formed so that the edges of the tieback hanger can snap
into
the opening and be engaged therein. In particular, as best shown in Figure
17C, the
window edges on which profiled areas 508 are formed include a recess 520
formed in
the thickness of the casing wall. Recess 520 is formed between profiled area
508 and
inner edge 522 of the window opening. Setting tab 518 is formed to wedge
against
profiled area 508 and engage into recess 520. Setting tab 518 includes an
extension
524 which can be snapped past edge 522 and be accommodated in recess 520. The
recesses and extensions can be any suitable shape, provided that each
extension can
fit into its corresponding recess. Preferably, trailing edges 525 of
extensions 524 are
chamfered to facilitate unsnapping of the tieback liner from the recess, if
desired.
Recesses and extensions can be elongate extending along selected lengths of
the
edges of the window. However, the positioning of the recesses and extensions
on their
respective parts must be selected so that they can be aligned and mated into
each
other.
CA 02527161 1998-08-18
In one embodiment, the distance dl across the setting tab 518 is slightly
greater than
the distance d2 across the window between the profiled areas 508. This
increases the
engagement of the tieback hanger in the window opening and strengthens the
casing
about the window by transmission of forces.
5 Preferably, all profiled areas 506, 508 and recesses are formed in the wall
thickness of
the casing without changing the ID or the OD of the casing at the window.
In addition to the recess/extension engagement or as an altemative thereto,
flanges
530 can be provided on the tieback hanger to abut against the edges of the
window
opening when the setting tab 516 are wedged between profiled areas 506.
Flanges
10 530 acts to abut against the casing to prevent the tieback hanger from
tipping back into
the casing bore. It is useful to provide both the profiled area 530 and the
recesses 520
to act as back up systems against each other.
Preferably all parts of the tieback hanger either sit within the window
opening or extend
outwardly of the window opening without extending into the bore of the casing,
so that
15 a sleeve, such as sleeve 123 of Figure 7A to 7C, can be rotated over the
window
opening 504.
It will be apparent that many other changes may be made to the illustrative
embodiments, while falling within the scope of the invention and it is
intended that all
such changes be covered by the claims appended hereto.
