U.S. patent application number 12/236405 was filed with the patent office on 2009-03-19 for method of running a tubing hanger and internal tree cap simultaneously.
This patent application is currently assigned to VETCO GRAY INC.. Invention is credited to Robert S. Buchan, Kevin G. Buckle, Gary A. Shaw.
Application Number | 20090071656 12/236405 |
Document ID | / |
Family ID | 40453238 |
Filed Date | 2009-03-19 |
United States Patent
Application |
20090071656 |
Kind Code |
A1 |
Shaw; Gary A. ; et
al. |
March 19, 2009 |
METHOD OF RUNNING A TUBING HANGER AND INTERNAL TREE CAP
SIMULTANEOUSLY
Abstract
An assembly for the completion of a subsea horizontal tree that
includes a tubing hanger, an internal tree cap, and a running
tool.
Inventors: |
Shaw; Gary A.; (Houston,
TX) ; Buchan; Robert S.; (Aberdeen, GB) ;
Buckle; Kevin G.; (Aberdeenshire, GB) |
Correspondence
Address: |
Todd D. Mattingly;BRACEWELL & GIULIANI LLP
P.O. Box 61389
Houston
TX
77208-1389
US
|
Assignee: |
VETCO GRAY INC.
Houston
TX
|
Family ID: |
40453238 |
Appl. No.: |
12/236405 |
Filed: |
September 23, 2008 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
11690373 |
Mar 23, 2007 |
|
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12236405 |
|
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Current U.S.
Class: |
166/368 ;
166/348 |
Current CPC
Class: |
E21B 33/043 20130101;
E21B 33/035 20130101 |
Class at
Publication: |
166/368 ;
166/348 |
International
Class: |
E21B 33/035 20060101
E21B033/035; E21B 43/36 20060101 E21B043/36 |
Claims
1. A method of completing a well comprising a treehead comprising a
bore, comprising: (a) connecting a running tool to an internal tree
cap and to a tubing hanger, then lowering the internal tree cap and
tubing hanger as an assembly, and landing the tubing hanger in the
bore of the treehead; then (b) locking the tubing hanger to the
bore of the treehead by injecting fluidic material into and through
the running tool and the tubing hanger; and then (c) locking the
internal tree cap to the bore of the treehead.
2. The method of claim 1, wherein (a) comprises: connecting a
lifting device of the running tool to the internal tree cap and
connecting a linking assembly between the internal tree cap and the
tubing hanger so that the internal tree cap supports the weight of
the tubing hanger through the linking assembly.
3. The method of claim 2, wherein (a) comprises: connecting a
pivoting linking assembly between the internal tree cap and the
tubing hanger so that the internal tree cap supports the weight of
the tubing hanger through the linking assembly.
4. The method of claim 3, wherein (a) comprises: connecting
internal and external pivoting linking assemblies between the
internal tree cap and the tubing hanger so that the internal tree
cap supports the weight of the tubing hanger through the linking
assembly.
5. The method of claim 2, wherein (a) comprises: locking the
lifting device of the running tool to an internal recess defined in
the internal tree cap.
6. The method of claim 1, wherein the tubing hanger comprises a
radially movable locking element and an axially movable actuator;
and wherein (b) comprises stroking the actuator of the tubing
hanger to cause the locking element of the tubing hanger to move
radially into a lower profile formed in the bore of the
treehead.
7. The method of claim 1, wherein the internal tree cap comprises a
radially movable locking element and an axially movable actuator;
and wherein (c) comprises stroking the actuator of the internal
tree cap to cause the locking element of the internal tree cap to
move radially into an upper profile formed in the bore of the
treehead.
8. The method of claim 1, wherein the internal tree cap and the
tubing hanger each comprise a radially movable locking element and
an axially movable actuator; wherein (b) comprises stroking the
actuator of the tubing hanger to cause the locking element of the
tubing hanger to move radially into a lower profile formed in the
bore of the treehead; and wherein (c) comprises stroking the
actuator of the internal tree cap to cause the locking element of
the internal tree cap to move radially into an upper profile formed
in the bore of the treehead.
9. The method of claim 1, wherein the running tool comprises a
longitudinal passage; and wherein the tubing hanger comprises a
radial passage coupled thereto.
10. The method of claim 1, further comprising, after (c),
retrieving the running tool.
11. The method of claim 1, further comprising, after (c),
retrieving the internal tree cap and the linking assembly.
12. A well assembly, comprising: a treehead comprising a bore
comprising upper and lower profiles; a tubing hanger defining a
radial passage and comprising a radially movable locking element
and an axially movable actuator for moving the locking element of
the tubing hanger into engagement with the lower profile; an
internal tree cap having a radially movable locking element and an
axially movable actuator for moving the locking element of the
internal tree cap into engagement with the upper profile; a linking
assembly for coupling the tubing hanger and the internal tree cap;
and a running tool defining a longitudinal passage operably coupled
to the radial passage of the tubing hanger comprising a lift member
that releasably engages a portion of the internal tree cap for
lowering the tree cap into the bore of the treehead, and an
actuator sleeve that releasably engages the actuator of the
internal tree cap to stroke the actuator of the internal tree
cap.
13. The assembly of claim 12, wherein the actuator of the tubing
hanger is moved axially by fluidic pressure.
14. The assembly of claim 12, wherein the linking assembly engages
profiles formed in the tubing hanger and the internal tree cap.
15. The assembly of claim 12, wherein the linking assembly
comprises: an internal linking assembly; and an external linking
assembly.
16. The assembly of claim 12, wherein the linking assembly is
pivotally coupled to the internal tree cap.
17. The assembly of claim 12, wherein the lift member is pivotally
coupled to the running tool.
18. The assembly of claim 12, wherein the internal tree cap
supports substantially all of the weight of the tubing hanger.
19. An assembly for completing a treehead that comprises a bore
comprising upper and lower profiles, comprising: a tubing hanger
defining a radial passage and comprising a radially movable locking
element and an axially movable actuator for moving the locking
element of the tubing hanger into engagement with the lower profile
of the treehead; an internal tree cap having a radially movable
locking element and an axially movable actuator for moving the
locking element of the internal tree cap into engagement with the
upper profile of the treehead; and a linking assembly for coupling
the tubing hanger and the internal tree cap.
Description
CROSS REFERENCE TO RELATED APPLICATIONS
[0001] The present application is a continuation-in-part of U.S.
utility patent application Ser. No. 11/690,373, attorney docket
number V2006068, filed on Mar. 23, 2007, the disclosure of which is
incorporated herein by reference.
FIELD OF THE INVENTION
[0002] This invention relates in general to subsea wellhead
equipment, and in particular to a method of simultaneously running
an internal tree cap and tubing hanger into a subsea horizontal
treehead.
BACKGROUND OF THE INVENTION
[0003] A conventional subsea horizontal tree includes a wellhead
housing which contains one or more casing hangers, one of which is
secured to a string of production casing that extends into the
well. A horizontal tree body, also known as a tree or tubing spool
or spool tree, mounts to the top of the wellhead housing and seals
to it. The horizontal tree body has a central bore axially through
it and a horizontal or lateral production flow passage through the
wall of the horizontal tree body. A tubing hanger lands and seals
in the central bore of the horizontal tree body and is secured to a
string of tubing that extends through the production casing hanger
and production casing into the well. The tubing hanger has a
production bore axially through it that is in fluid communication
with the tubing. The tubing hanger also has a lateral flow passage
in fluid communication with the tubing hanger production bore and
with the lateral production flow passage in the horizontal tree
body.
[0004] Annular seals are located between the tubing hanger and the
central bore of the horizontal tree body above the production flow
passage to provide primary, and occasionally, secondary barriers to
leakage from the production flow pathways and well bore.
Additionally, one or more wireline deployable plugs fit in one or
more lockdown profiles in the tubing hanger production bore to
provide primary, and occasionally, secondary barriers to leakage
from the production and well bores. A tree cap may also fit above
the tubing hanger in the central bore of the horizontal tree body.
The tree cap may be of an internal or external lockdown
configuration. In either case, the tree cap will seal to the
central bore of the horizontal tree body and act as an additional
barrier to leakage from the well. The tree cap of either
configuration may have a vertical bore through it.
[0005] Another typical feature of subsea horizontal trees is an
annulus and workover passageway that establishes a fluid
communication pathway between the annular space around the tubing
below the tubing hanger and a space inside the central bore of the
horizontal tree body above the tubing hanger. This annulus and
workover passageway can be ported through the tubing hanger,
through the horizontal tree body or a combination of both.
Alternatively, the annulus and workover passageway may be ported
entirely out of the tree from a position below the tubing
hanger.
[0006] In practice, there are generally two horizontal tree
configurations: (1) a horizontal tree with a tubing hanger fitted
with one or more plugs in its production bore and an internal tree
cap, with a plug in its vertical bore; or (2) a horizontal tree
with a tubing hanger fitted with at least two plugs in its
production bore and eliminating the internal tree cap. This second
style of horizontal tree typically utilizes a tree cap that locks
externally to the tree body and may or may not include a seal to
the tree body. In either tree cap case, the annulus and workover
passageway will contain at least two closure members in the form of
gate valves, for example.
[0007] The primary difference between these two general horizontal
tree configurations is that the first has a primary and secondary
barrier that employs independent lockdown structures for the two
barriers, and the second has a primary and secondary barrier that
ultimately rely on the tubing hanger to horizontal tree body
lockdown structure. Some operators, and some regulatory authorities
believe that the first and second horizontal tree configurations
are equivalently safe in operation. Other operators and regulatory
authorities believe only the first configuration meets the dual
barrier industry philosophies and/or regulatory requirements.
[0008] One advantage of the second configuration is that the
elimination of the internal tree cap eliminates the need for a
second drill pipe run to install it. In running (or working over)
the first style of horizontal tree, the tubing hanger is run into
the horizontal tree body typically on a hydraulically-actuated
running tool that is run on drill pipe. Afterwards, the internal
tree cap is run into the horizontal tree body typically on the same
hydraulically-actuated running tool, or one very similar, on drill
pipe. This results in two drill pipe trips to the seafloor.
[0009] In running (or working over) the second style of horizontal
tree, the tubing hanger is run into the horizontal tree body
typically on the hydraulically-actuated running tool on drill pipe.
Afterwards, a lower plug is run on wireline and landed, locked and
sealed to the production bore of the tubing hanger and then an
upper plug is run on wireline and landed, locked and sealed to the
production bore above the first plug. In deeper water wells, this
results in potentially significant rig time savings. However, it
comes with the compromise that the two plugs rely on the single
tubing hanger lockdown mechanism to ensure that the tubing string
assembly does not part from the tree and cause potentially
significant leakage of the well bore to the environment.
BRIEF DESCRIPTION OF THE DRAWINGS
[0010] FIG. 1 is a fragmentary cross sectional illustration of an
exemplary embodiment of a tubing hanger and internal tree cap
assembly.
[0011] FIG. 2 is a fragmentary cross sectional illustration of the
tubing hanger and internal tree cap assembly of FIG. 1 during
assembly.
[0012] FIG. 3 is a fragmentary cross sectional illustration of the
tubing hanger and internal tree cap assembly of FIG. 2 during
further assembly.
[0013] FIG. 4 is a fragmentary cross sectional illustration of the
tubing hanger and internal tree cap assembly of FIG. 3 during
placement of the assembly within an end of a treehead.
[0014] FIG. 5 is a fragmentary cross sectional illustration of the
tubing hanger and internal tree cap assembly of FIG. 4 during
operation of the assembly to connect the tubing hanger to the
treehead.
[0015] FIG. 6 is a fragmentary cross sectional illustration of the
tubing hanger and internal tree cap assembly of FIG. 5 during
operation of the assembly to connect the internal tree cap to the
treehead.
[0016] FIG. 7 is a fragmentary cross sectional illustration of the
tubing hanger and internal tree cap assembly of FIG. 6 during
operation of the assembly to unlock the running tool from the
internal tree cap.
[0017] FIG. 8 is a fragmentary cross sectional illustration of the
tubing hanger and internal tree cap assembly of FIG. 7 during
operation of the assembly to remove the running tool from the
treehead.
[0018] FIG. 9 is a fragmentary cross sectional illustration of the
tubing hanger and internal tree cap assembly of FIG. 8 during
operation of the assembly to position crown plugs within the
internal tree cap and the tubing hanger.
[0019] FIG. 10 is a fragmentary cross sectional illustration of the
tubing hanger and internal tree cap assembly of FIG. 9 during
operation of the assembly to remove the crown plugs and the
internal tree cap from the treehead.
DETAILED DESCRIPTION OF THE INVENTION
[0020] In the drawings and description that follows, like parts are
marked throughout the specification and drawings with the same
reference numerals, respectively. The drawings are not necessarily
to scale. Certain features of the invention may be shown
exaggerated in scale or in somewhat schematic form and some details
of conventional elements may not be shown in the interest of
clarity and conciseness. The present invention is susceptible to
embodiments of different forms. Specific embodiments are described
in detail and are shown in the drawings, with the understanding
that the present disclosure is to be considered an exemplification
of the principles of the invention, and is not intended to limit
the invention to that illustrated and described herein. It is to be
fully recognized that the different teachings of the embodiments
discussed below may be employed separately or in any suitable
combination to produce desired results. The various characteristics
mentioned above, as well as other features and characteristics
described in more detail below, will be readily apparent to those
skilled in the art upon reading the following detailed description
of the embodiments, and by referring to the accompanying
drawings.
[0021] Referring to FIG. 1, a tubing hanger and internal tree cap
assembly 100 includes a tubing hanger 102 that defines an internal
passage 102a and a radial passage 102b and includes an internal
annular recess 102c, an internal annular recess 102d at one end, an
external annular recess 102e, an external annular recess 102f, an
external annular recess 102g, an external annular recess 102h, an
external annular recess 102i, an external annular recess 102j, and
internal threaded portion 102k at one end.
[0022] A tubular locking ring retainer 104 defines a window 104a
and includes a tapered external shoulder 104b that mates with and
is supported on the annular external recess 102e of the tubing
hanger 102 and an internal annular recess 104c. A conventional
split locking ring 106 is received within the window 104a of the
locking ring retainer 104 and includes a profiled external surface
106a and a tapered internal surface 106b. An end of a sleeve 108 is
mates with and is supported on the external annular recess 102g of
the tubing hanger 102 and another end of the sleeve mates with and
is supported on the external annular recess 102h of the tubing
hanger 102.
[0023] A tubing hanger support 110 defines a radial passage 110a
that is operably coupled to the radial passage 102b of the tubing
hanger 102 and includes an internal annular recess 110b at one end
that mates with an end of the sleeve 108, an internal flange 110c
that mates with and is received within the external annular recess
102h of the tubing hanger, an internal annular recess 110d that
mates with the external annular recess 102i of the tubing hanger,
an internal flange 110e that mates with and is received within the
external annular recess 102i of the tubing hanger, an external
flange 110f, an external annular recess 110g, and an internal
profiled annular recess 110h. An energizing ring 112 includes a
tapered external annular recess 112a at one end, internal grooves
112b at one end, an internal annular recess 112c that mates with an
receives a portion of the tubing hanger support 110, an internal
annular recess 112d that mates with and receives the external
flange 110f of the tubing hanger support, a tapered internal
annular recess 112e, and an internal annular recess 112f.
[0024] A lower end of a tubular support member 114 is positioned in
opposing relation to an upper end of the tubing hanger support 110
and includes an internal annular recess 114a, an external annular
recess 114b, an external threaded portion 114c at an upper end, and
an external threaded portion 114d at the upper end. A tubular
support member 116 includes a tapered internal annular recess 116a
at one end, an internal threaded portion 116b at another end that
engages the external threaded portion 114c of the tubular support
member 114, a tapered external annular recess 116c at the other
end, an external annular recess 116d, an external annular recess
116e, and an external annular recess 116f that mates with an upper
end of the energizing ring 112. A snap ring 118 is at least
partially received within the external annular recess 116e of the
tubular support member 116 and the internal annular recess 112f of
the energizing ring 112. In this manner, the snap ring 118
releasably holds the upper end of the energizing ring 112 within
the external annular recess external annular recess 116f of the
tubular support member 116.
[0025] An upper end 120a of a locking dog 120 is retained within
the external annular recess 114b of the tubular support member 114
by the tapered internal annular recess 116a of the tubular support
member 116 and a lower end 120b of the locking dog is retained
within the external annular recess 110g of the tubing hanger
support 110 by the energizing ring 112. A tubular support 122
defines a window 122a and includes an internal threaded portion
122b at one end that is coupled to an external threaded portion
102k of the tubing hanger 102. An upper end 124a of a latch dog 124
is retained within the internal annular recess 114a of the tubular
support member 114 by the upper portion of the tubular support 122
and a lower end 124b of the latch dog mates with and is received
within the internal annular recess 110h of the tubing hanger
support 110. In an exemplary embodiment, the locking dog 120 and
the latch dog 124, either alone or in combination, provide a
linking assembly for linking the internal tree cap 126 and the
tubing hanger 102. Furthermore, in an exemplary embodiment, as a
result, the internal tree cap 126 supports the weight on the tubing
hanger 102.
[0026] An internal tree cap 126 includes an external annular recess
126a at one end, a channel 126b at one end that receives and mates
with the upper ends of the tubular support member 114 and the
tubular support member 116, an internal tapered annular recess 126c
at one end that mates with and receives an upper end of the tubular
support 122, an internal annular recess 126d, an internal profiled
annular recess 126e, an channel 126e, an external annular recess
126f, an external annular recess 126g, an external annular recess
126h, an external annular recess 126i at another end, an internal
annular recess 126j at another end, and an external tapered annular
recess 126k at a lower end. A sleeve 128 includes an external
ribbed surface 128a at one end, an internal annular recess 128b at
one end, and another end that mates with and is received within the
external annular recess 126h of the internal tree cap 126. A
tubular support member 130 includes an internal annular recess 130a
at one end that mates with and receives an upper end of the sleeve
128, an internal annular recess 130b that mates with and is
received within the external annular recess 126h of the internal
tree cap 126, another end that mates with and is received within
the external annular recess 126i of the internal tree cap 126, an
external annular recess 130c, an external flange 130d, and an
external flange 130e that defines a longitudinal passage 130f
therethrough.
[0027] An energizing ring 132 that includes an internal profiled
annular recess 132a, an internal annular recess 132b that receives
and mates with the external flange 130e of the tubular support
member 130, an internal annular recess 132c that receives and mates
with a lower end of the tubular support member 130, an external
tapered external annular recess 132d at another end, and an
internal ribbed surface 132e at another end, mates with and
receives the sleeve 128. A conventional split locking ring 134 is
received within the external annular recesses, 126f and 126g, of
the internal tree cap 126, and includes a profiled external surface
134a and a tapered internal surface 134b.
[0028] An upper tubular running tool 136 that defines a radial
passage 136a at one end and a longitudinal passage 136b that
depends therefrom and extends to another end, and includes a
tapered external annular recess 136c and an internal annular recess
136d at the other end is received within an mates with the internal
tree cap 126. A lower tubular running tool 138 that defines a
longitudinal passage 138a that is and a radial passage 138b that
extends therefrom and includes a tapered external flange 138d that
is received within and mates with the internal annular recess 126d
of the internal tree cap 126, and an external annular recess 138e
that receives and mates with the tubing hanger 102 includes an
upper end that mates with and is received within a lower end of the
upper tubular running tool 136. A tubular conduit 140 extends
between and operably couples opposing ends of the passageways, 136b
and 138a, of the upper and lower tubular running tools, 136 and
138, respectively. A tool finger 142 is pivotally coupled to an
outer surface of the lower tubular running tool 138 proximate the
external flange 138d for pivotal movement relative thereto.
[0029] Referring now to FIG. 2, in an exemplary embodiment, the
upper tubular running tool 136 is then displaced in the direction
of the lower tubular running tool 138. As a result, the external
tapered annular recess 136c of the upper tubular running tool 136
is displaced into engagement with the tool finger 142 thereby
pivoting the tool finger outwardly in a radial direction and into
the profiled internal annular recess 126e of the internal tree cap
126 thereby locking the internal tree cap to the lower tubular
running tool 138. Furthermore, as a result, the internal annular
recess 136d of the upper tubular running tool is displaced into
engagement with the upper end of the lower tubular running tool 138
thereby displacing the conduit 140 into the upper end of the
longitudinal passage 138a of the lower tubular running tool.
[0030] Referring now to FIG. 3, in an exemplary embodiment, a
universal running tool 200 is then coupled to the assembly 100 that
includes an inner sleeve 202 that defines a longitudinal passage
202a and a radial passage 202b that depends therefrom and includes
an internal annular recess 202c at one end. At least a portion of
an upper end of the upper tubular running tool 136 is received
within and mates with a lower portion of the inner sleeve 202. An
inner sleeve 204 that defines a radial passage 204a is received
within and mates with the internal annular recess 202c of the inner
sleeve 202, receives and mates with the upper tubular running tool
136, and is received within and mates with the internal annular
recess 126j of the internal tree cap 126.
[0031] An internal sleeve 206 that defines an internal annular
recess 206a receives and mates with the inner sleeve 202 and is
received within and mates with the internal annular recess 132b of
the energizing ring 132. An internal sleeve 208 is received within
and mates with the internal annular recess 206a of the internal
sleeve. An internal sleeve 210 is coupled to an end of the inner
sleeve 202 and positioned within the annular recess 206a of the
internal sleeve 206 and an end of the internal sleeve 210 is
received within and mates with the external annular recess 130c of
the tubular support member 130. An outer sleeve 212 that defines an
internal annular recess 212a and an internal annular recess 212b
receives and mates with the inner sleeve 206. An upper end 214a of
a latch 214 is received within the internal annular recess 212a of
the outer sleeve 212 and a lower end 214b of the latch is received
within the internal annular recess 132a of the energizing ring
132.
[0032] An upper end 216a of a locking sleeve 216 is received within
and mates with the internal annular recess 206a of the inner sleeve
206 and is positioned proximate a lower end of the internal sleeve
208 and above at least a portion of the internal sleeve 210 and a
lower end 216b of the locking sleeve 216 is received within and
mates with the internal annular recess 206a of the inner sleeve 206
and is positioned below at least a portion of the internal sleeve
210. In this manner, the universal running tool 200 is locked to
the internal tree cap 126.
[0033] Referring now to FIG. 4, in an exemplary embodiment, the
coupled assemblies, 100 and 200, are then run into an open end of a
conventional treehead 300 that includes an upper profiled internal
annular recess 302, an internal load shoulder 304, a lower profiled
internal annular recess 306, and an internal load shoulder 308. In
particular, the coupled assemblies, 100 and 200, are then run into
an open end of the treehead 300 until the external tapered annular
recess 126k of the internal tree cap 126 lands on the internal load
shoulder 304 of the treehead 300 and the tapered external shoulder
104b of the locking ring retainer 104 lands on the internal load
should 308 of the treehead.
[0034] Referring now to FIG. 5, in an exemplary embodiment, a pump
400 is then operated to inject a fluidic material into and through
the passage 202a of the sleeve 200. As a result, fluidic material
is then conveyed into and through the passages, 204a, 136a, 136b,
the conduit 140, and the passages 138a, 138b, 102b, and 110g. As a
result, the energizing ring 112 is displaced downwardly into
engagement with the locking ring 106. As a result, the interaction
of the tapered external annular recess 112a of the energizing ring
112 with the tapered internal surface 106b of the locking ring 106
causes the locking ring to be displaced outwardly in a radial
direction into engagement with the profiled internal recess 306 of
the treehead 300.
[0035] Furthermore, the downward displacement of the energizing
ring 112 also moves the energizing ring out of engagement with the
lower end 120b of the a locking dog 120. As a result, the lower end
120b of the locking dog 120 may pivot outwardly out of engagement
with the external annular recess 110g of the tubing hanger support
110.
[0036] Referring now to FIG. 6, in an exemplary embodiment, the
outer sleeve of the assembly 200 is displaced downwardly thereby
causing the energizing ring 132 to be displaced downwardly. As a
result, the interaction of the tapered external annular recess 132d
of the energizing ring 132 with the tapered internal surface 134b
of the locking ring 134 causes the locking ring to be displaced
outwardly in a radial direction into engagement with the profiled
internal recess 302 of the treehead 300 thereby locking the
internal tree cap 126 to the treehead 300. In an exemplary
embodiment, as a result, the internal tree cap 126 then at least
partially supports the weight of the tubing hanger 102 and the
upper and lower tubular running tools, 136 and 138.
[0037] Referring now to FIG. 7, in an exemplary embodiment, the
upper tubular running tool 136 is then displaced upwardly relative
to the lower tubular running tool 138. As a result, the external
tapered annular recess 136c of the upper tubular running tool 136
is moved out of engagement with the tool finger 142. As a result,
the tool finger 142 may pivot out of engagement with the internal
annular recess 126e of the internal tree cap 126 thereby unlocking
the internal tree cap from the lower tubular running tool 138.
[0038] Referring now to FIG. 8, in an exemplary embodiment, the
upper and lower tubular running tools, 136 and 138, are then
removed. As a result, the lower end 124b of the latch dog 124 may
pivot out engagement with the internal annular recess 110h of the
tubing hanger support 110.
[0039] Referring now to FIG. 9, in an exemplary embodiment,
conventional crown plugs, 500a and 500b, may then be coupled to the
profiled internal annular recesses, 126e and 102c, of the internal
tree cap 126 and the tubing hanger 102, respectively, in a
conventional manner.
[0040] Referring now to FIG. 10, in an exemplary embodiment, the
crown plugs, 500a and 500b, may then be decoupled from the profiled
internal annular recesses, 126e and 102c, of the internal tree cap
126 and the tubing hanger 102, respectively, in a conventional
manner. In an exemplary embodiment, the energizing ring 132 may
then be displaced upwardly relative to the locking ring 134 thereby
decoupling the locking ring from the profiled inner annular recess
302 of the treehead 300. As a result, the internal tree cap 126 is
no longer locked to the treehead 300. In an exemplary embodiment,
the assembly 200 may then be displaced upwardly relative to the
treehead 300. As a result, the tubular support member 114, the
tubular support member 116, the locking dog 120, the tubular
support 122, the latch dog 124, the internal tree cap 126, the
sleeve 128, the tubular support member 130, the energizing ring
132, and the locking ring 134 are also displaced upwardly out of
the treehead 300 and out of engagement with the tubing hanger
102.
[0041] It is understood that variations may be made in the above
without departing from the scope of the invention. For example, the
teachings of the exemplary embodiments may also be used to complete
a wellhead, treehead, or other equivalent structure. While specific
embodiments have been shown and described, modifications can be
made by one skilled in the art without departing from the spirit or
teaching of this invention. The embodiments as described are
exemplary only and are not limiting. Many variations and
modifications are possible and are within the scope of the
invention. Accordingly, the scope of protection is not limited to
the embodiments described, but is only limited by the claims that
follow, the scope of which shall include all equivalents of the
subject matter of the claims.
* * * * *