U.S. patent application number 09/805090 was filed with the patent office on 2002-08-01 for production flow tree cap.
Invention is credited to Beall, Scott K., Garrett, Michael R., Ortiz, Rogelio.
Application Number | 20020100592 09/805090 |
Document ID | / |
Family ID | 25190648 |
Filed Date | 2002-08-01 |
United States Patent
Application |
20020100592 |
Kind Code |
A1 |
Garrett, Michael R. ; et
al. |
August 1, 2002 |
Production flow tree cap
Abstract
A christmas tree to control the production from a subsea oil or
gas well is disclosed. The christmas tree design including a tree
body having a first flow port and a tree cap; a tubing hanger
landed within the tree body; an actuation mandrel landed within the
tree body, the actuation mandrel having a flow port; and a flow
diverter disposed within the tree cap to divert flow through the
flow port. The christmas tree arrangement allows for dual barriers
within the tree cap without placing or retrieving any plugs from
within the tubing hanger, thereby reducing the number of downhole
trips required to complete and/or service the subsea well.
Inventors: |
Garrett, Michael R.;
(Richmond, TX) ; Beall, Scott K.; (Houston,
TX) ; Ortiz, Rogelio; (Houston, TX) |
Correspondence
Address: |
HOWREY SIMON ARNOLD & WHITE LLP
750 BERING DRIVE
HOUSTON
TX
77057
US
|
Family ID: |
25190648 |
Appl. No.: |
09/805090 |
Filed: |
March 13, 2001 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
09805090 |
Mar 13, 2001 |
|
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|
09770588 |
Jan 26, 2001 |
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Current U.S.
Class: |
166/378 ;
166/368 |
Current CPC
Class: |
E21B 33/043 20130101;
E21B 33/035 20130101; E21B 33/076 20130101; E21B 34/04 20130101;
E21B 34/02 20130101; E21B 33/068 20130101 |
Class at
Publication: |
166/378 ;
166/368 |
International
Class: |
E21B 033/035 |
Claims
What is claimed is:
1. A christmas tree to control the production from a subsea oil or
gas well comprising: a) a tree body having a first production flow
port; b) a tubing hanger landed within the tree body; c) an
actuation mandrel landed within the tree body, the actuation
mandrel having a second production flow port in fluid communication
with said first flow port; and d) a flow diverter disposed within
the actuation mandrel to divert flow through the production flow
ports.
2. The christmas tree of claim 1 further comprising a backup flow
diverter disposed within the actuation mandrel.
3. The christmas tree of claim 2 wherein the flow diverter and
backup flow diverter comprise plugs.
4. The christmas tree of claim 1 wherein the plugs are set by
wireline.
5. The christmas tree of claim 1 wherein the first flow port is a
production flow port.
6. The christmas tree of claim 5 wherein the first flow port is a
radial bore through the tree body.
7. The christmas tree of claim 1 wherein the tree body comprises a
second flow port.
8. The christmas tree of claim 7 wherein the second flow port
comprises an annulus flow port.
9. The christmas tree of claim 8 wherein annulus flow port
comprises a first partial bore, a second partial bore, and a
channel extending therebetween.
10. The christmas tree of claim 9 wherein the channel extends
substantially longitudinally along the tree body.
11. The christmas tree of claim 9 wherein the first and second
partial bores are arranged opposite one another.
12. The christmas tree of claim 1 wherein the tree body further
comprises an integral production valve.
13. The christmas tree of claim 1 wherein the tree body further
comprises a first countersunk area receptive of a production valve
assembly.
14. The christmas tree of claim 13 wherein the tree body further
comprises a second countersunk area receptive of an annulus flow
assembly.
15. The christmas tree of claim 14 wherein the annulus flow
assembly attaches to external fluid circulation lines.
16. The christmas tree of claim 15 wherein the external fluid
circulation lines comprise choke or kill lines.
17. The christmas tree of claim 7 further comprising a third flow
port.
18. The christmas tree of claim 17 wherein the third flow port
provides fluid communication to a downhole safety valve.
19. The christmas tree of claim 18 wherein the third flow port is
receptive of a hydraulic penetrator to establish fluid
communication to the downhole safety valve.
20. The christmas tree of claim 17 further comprising a fourth flow
port.
21. The christmas tree of claim 20 wherein the fourth flow port
provides for chemical injection into the well.
22. A method of controlling production from a subsea oil or gas
well comprising steps of: a) installing a side valve tree onto a
wellhead; b) running a tubing hanger into the wellbore; c) landing
the tubing hanger in the tree body; d) installing an actuation
mandrel with a plurality of plugs set therein; wherein there are no
plugs set in the tubing hanger.
23. The method of claim 22 further wherein the step of installing a
side valve tree onto a wellhead further comprises providing a tree
bore protector.
24. The method of claim 22 wherein the tubing hanger comprises a
production tubing suspended therefrom.
25. The method of claim 22 wherein the tubing hanger comprises an
orientation key mating with an orientation sleeve.
26. The method of claim 25 further comprising the step of orienting
the tubing hanger within the tree body.
27. The method of claim 22 further comprising the step of locking
the tubing hanger within the tree body.
28. The method of claim 22 wherein the step of installing an
actuation mandrel with a plurality of plugs set therein further
comprises orienting the actuation mandrel.
29. The method of claim 22 wherein the actuation mandrel comprises
a plurality of reduced-diameter shoulders and pack-off seals.
30. The method of claim 29 wherein the step of installing an
actuation mandrel with a plurality of plugs set therein further
comprises landing the shoulders and seal within the tree body.
31. A method of servicing a subsea oil or gas well with a
side-valve christmas tree comprising steps of: a) running an
actuation mandrel retrieval tool into the christmas tree; b)
engaging the actuation mandrel retrieval tool with the actuation
mandrel; c) retrieving the actuation mandrel; and d) retrieving a
tubing hanger; wherein there is no step of retrieving any plugs
from within the tubing hanger.
Description
[0001] This is a continuation-in-part of U.S. patent application
Ser. No. 09/770,588, filed Jan. 26, 2001.
FIELD OF THE INVENTION
[0002] This invention relates generally to subsea oil and gas
production methods and apparatus and, more particularly, to a split
tree cap christmas tree.
BACKGROUND OF THE INVENTION
[0003] The proliferation of rules and regulations for producing and
transporting oil, gas, and other products over the years has led to
many advances in well equipment and methodology. One object of
particular concern in drilling, completion, and workover operations
of a subsea well is that at all times there be at least two
barriers between the production fluids and the local environment.
The standard use of a double barrier prevents contamination in the
event of a failure of the first barrier, whether that barrier is is
a seal, a valve, or some other apparatus.
[0004] In a typical well completion with a horizontal tree, it is
conventional practice to complete the subsea well with a tubing
hanger having a production tubing string suspended therefrom. The
tubing hanger and the associated production tubing are run into a
subsea horizontal tree on a running assembly usually comprising a
tubing hanger running tool and a riser until the tubing hanger is
landed and sealed in the horizontal tree. Typically the production
tubing includes a downhole safety valve to shut-in production, if
necessary. The wellhead carries a blowout preventer (BOP) stack
which is connected to a marine riser through which the tubing
hanger is run. Often the horizontal tree contains a plug or tree
cap that provides a first barrier to production fluids above the
tubing hanger and the production tubing in the horizontal christmas
tree. A second barrier to the environment is typically provided by
a second plug located within the production tubing hanger when the
tubing hanger is run or retrieved.
[0005] As the well nears completion, or (in a completed well) when
a workover or other well service operation is necessary, it is
conventional practice to install or retrieve the plug in the tubing
hanger to ensure a dual barrier to the ambient environment at all
times. The installation of a plug in the tubing hanger becomes
necessary, for example, when an operator needs to remove the BOP.
However, the setting and/or retrieving of the plug in the tubing
hanger requires a separate trip--usually by wireline. Because well
drilling and completion operations are very expensive and often
based on per hour rig charges, it is desirable to complete and/or
service wells with as few downhole trips as possible to reduce rig
time. It would be desirable and cost efficient to find a system
that would allow well completion and servicing options without
setting and retrieving the tubing hanger plug.
SUMMARY OF THE INVENTION
[0006] There is disclosed a christmas tree to control the
production from a subsea oil or gas well. In one embodiment the
system includes a tree body having a first flow port and a tree
cap; a tubing hanger landed within the tree body; an actuation
mandrel landed within the tree body, the actuation mandrel having a
flow port; and a flow diverter disposed within the tree cap to
divert flow through the flow port. The system may further include a
backup flow diverter disposed within the tree cap, the flow
diverters including plugs. In some embodiments the plugs are set by
wireline.
[0007] In one embodiment of the christmas tree the first flow port
is a production flow port. This first flow port may be a radial
bore extending through the tree body.
[0008] In one embodiment the christmas tree includes a second flow
port. This second flow port may be an annulus flow port. The
annulus flow port may include a first partial bore, a second
partial bore, and a channel extending therebetween. The channel may
extend substantially longitudinally along the tree body. In one
embodiment the first and second partial bores are arranged opposite
one another.
[0009] In one embodiment the christmas tree further includes an
integral production valve. In another embodiment the christmas tree
includes a first countersunk area receptive of a production valve
assembly.
[0010] In one embodiment the christmas tree further includes a
second countersunk area receptive of an annulus flow assembly. The
annulus flow assembly may attach to external fluid circulation
lines. The external fluid circulation lines may include choke or
kill lines.
[0011] In one embodiment the christmas tree further includes a
third flow port. The third flow port provides fluid communication
to a downhole safety valve. The third flow port may be receptive of
a hydraulic penetrator to establish fluid communication to the
downhole safety valve.
[0012] In one embodiment the christmas tree further includes a
fourth flow port. The fourth flow port may provide for chemical
injection into the well.
[0013] There is also disclosed a method of controlling production
from a subsea oil or gas well, the method including the steps of:
installing a side valve tree onto a wellhead, the side valve tree
including a tree cap; running a tubing hanger into the wellbore;
landing the tubing hanger in the tree body; installing an actuation
mandrel with a plurality of plugs set therein; wherein the
plurality of plugs are disposed within the tree cap and there are
no plugs set in the tubing hanger.
[0014] The step of installing a side valve tree onto a wellhead may
further include providing a tree bore protector.
[0015] According to the disclosed method the tubing hanger may
include a production tubing suspended therefrom. The tubing hanger
may include an orientation key mating with an orientation sleeve.
Therefore, the method may further include the step of orienting the
tubing hanger within the tree body.
[0016] In one embodiment the method may include the step of locking
the tubing hanger within the tree body.
[0017] In one embodiment the step of installing an actuation
mandrel with a plurality of plugs set therein includes orienting
the actuation mandrel. The actuation mandrel may include a
plurality of reduced-diameter shoulders and pack-off seals.
[0018] In one embodiment the step of installing an actuation
mandrel with a plurality of plugs set therein further comprises
landing the shoulders and seals within the tree body.
[0019] There is also disclosed a method of servicing a subsea oil
or gas well with a side-valve christmas tree including the steps
of: running an actuation mandrel retrieval tool into the christmas
tree; engaging the actuation mandrel retrieval tool with the
actuation mandrel; retrieving the actuation mandrel; and retrieving
a tubing hanger; wherein there is no step of retrieving any plugs
from within the tubing hanger.
BRIEF DESCRIPTION OF THE DRAWINGS
[0020] The foregoing and other features and aspects of the
invention will become further apparent upon reading the following
detailed description and upon reference to the drawings in
which
[0021] FIG. 1A depicts a split tree cap christmas tree design in
accordance with one aspect of the invention.
[0022] FIG. 1B depicts a detail of the split tree cap christmas
tree design of FIG. 1A.
[0023] FIG. 1C depicts a split tree cap christmas tree design in
accordance with another aspect of the invention.
[0024] FIG. 1D depicts a split tree cap christmas tree design
according to FIG. 1C in the run-in position.
[0025] FIG. 2 depicts a split tree cap christmas tree in
diagramatic form.
[0026] FIG. 3 is a schematic drawing of the christmas tree design
of FIG. 1.
[0027] FIG. 4 diagrammatically depicts a split tree cap christmas
tree with a tree bore protector installed.
[0028] FIGS. 5A and 5B diagrammatically depict a split tree cap
christmas tree during the installation of a tubing hanger.
[0029] FIG. 6 depicts a split tree cap christmas tree during
installation of a tubing hanger with alternate locked and unlocked
positions indicated.
[0030] FIGS. 7A and 7B diagrammatically depict a split tree cap
christmas tree with a tubing hanger installed, landed and
locked.
[0031] FIGS. 8A and 8B diagrammatically depict a split tree cap
christmas tree with a tubing hanger installed, landed and locked
during retrieval of the tubing hanger running tool.
[0032] FIG. 9 diagrammatically depicts a split tree cap christmas
tree with a tubing hanger installed and without running tools.
[0033] FIGS. 10A and 10B diagrammatically depict a split tree cap
christmas tree during the installation of a split tree cap and
plugs.
[0034] FIGS. 11A and 11B diagrammatically depict a split tree cap
christmas tree with a split tree cap installed, landed and
locked.
[0035] FIGS. 12A and 12B diagrammatically depict a split tree cap
christmas tree with a split tree cap installed, landed and locked
during retrieval of a tree cap running tool.
[0036] FIG. 13 diagrammatically depicts an embodiment of the split
tree cap christmas tree with the tubing hanger and split tree cap
installed.
[0037] While the invention is susceptible to various modifications
and alternative forms, specific embodiments thereof have been shown
by way of example in the drawings and are herein described in
detail. It should be understood, however, that the description
herein of specific embodiments is not intended to limit the
invention to the particular forms disclosed, but on the contrary,
the intention is to cover all modifications, equivalents, and
alternatives falling within the spirit and scope of the invention
as defined by the appended claims.
DESCRIPTION OF ILLUSTRATIVE EMBODIMENTS
[0038] Illustrative embodiments of the invention are described
below. In the interest of clarity, not all features of an actual
implementation are described in this specification. It will of
course be appreciated that in the development of any such actual
embodiment, numerous implementation-specific decisions must be made
to achieve the developers' specific goals, such as compliance with
system-related and business-related constraints, that will vary
from one implementation to another. Moreover, it will be
appreciated that such a development effort might be complex and
time-consuming, but would nevertheless be a routine undertaking for
those of ordinary skill in the art having the benefit of this
disclosure.
[0039] Turning now to the Figures, and in particular FIGS. 1A-D and
2, a split tree cap christmas tree design in accordance with one
embodiment of the invention is disclosed. Christmas tree system 2
includes a generally cylindrical side valve tree body 4. Side valve
tree body 4 defines an internal throughbore 6 extending
longitudinally therethrough. The upper end of side valve tree body
4 contains a radial profile 8 adapted to engage an external
connector. Profile 8 is intended to allow the connection of the
christmas tree body 4 to other subsea equipment such as running
tools, blowout preventers, and intervention packages by way of
example. Other means of connection known in the art are easily
applicable to connect the side valve tree body 4 to other equipment
as needed.
[0040] Also located at the upper end of side valve tree body 4 is a
radial internal running profile 10. Profile 10 provides a means to
connect the side valve tree body 4 to a tree running tool. In
addition, profile 10 is adapted to receive a lock down ring 92,
retained by an associated lock down sleeve 93, as discussed
below.
[0041] The lower end of side valve tree body 4 is adapted for
installation on a wellhead 100. Tree body 4 may be adapted for
installation on any standard size wellhead typically known in the
art, for example an 183/4 inch wellhead. A connector secures the
side valve tree body 4 to the wellhead 100 and resists the
separation forces resulting from the pressure developed in a live
well. A seal 102 disposed between the wellhead 100 and the side
valve tree body 4, typically a gasket seal such as an AX gasket,
prevents the passage of hydrocarbons to the environment at this
connection.
[0042] A flow port 12 constitutes a first bore through side valve
tree body 4. In the embodiment of FIGS. 1C and 1D, side valve tree
body 4 includes an integral valve 104. Production flow port 12 is
cut radially through side valve tree body 4. In the embodiment of
FIGS. 1A, 1B, and 2, the side valve tree body 4 contains a
countersunk area 14 circumscribing the flow port 12 to facilitate
attachment of a production valve assembly 110, as shown
schematically in FIG. 3. The production valve assembly 110 (or in
the embodiments of FIGS. 1C and 1D, integral production valve 104)
is generally controlled hydraulically, e.g. from the surface
through a control module, to regulate or stop the flow of
hydrocarbons from the well. Hydraulic control lines 112 and 114 are
indicated in FIG. 3. Electronically controlled valves are an option
to hydraulically controlled valves. The valve assembly 110
generally contains at least one valve, however, two are common as
indicated in FIG. 3 by production master valve 116 (PMV) and
production wing valve 118 (PWV).
[0043] In the embodiment shown in FIGS. 1A, 1B and 2, a flanged
connection fixes the valve assembly 110 to the side valve tree body
4. The countersunk area 14 may contain studs to facilitate the
attachment of the first valve 116 or the valve assembly 110 by
bolting. In other embodiments--such as those shown in FIGS. 1C and
1D--one of the valves or the entire valve assembly may be integral
to side valve tree body 4.
[0044] At least one seal 16 is disposed between the side valve tree
body 4 and the valve assembly 110 in the area of the flow port 12.
Seal 16 may be located within a groove 18, and may be an o-ring or
other resilient-type seal. Other embodiments may include
metal-to-metal seals, or other seals known in the art. Redundant
seals may also be disposed between the flow port 12 and the side
valve tree body 4.
[0045] FIGS. 1A and 1B also show a tubing annulus flow port 20
disposed within the wall of side valve tree body 4. Similar ports
may be included in the side valve tree body 4 shown in FIGS. 1C and
1D, although they are not shown. Tubing annulus flow port 20 enters
the external wall of the tree body 4 at a suitable location to
avoid the body of a connector, when such a connector is installed.
In one embodiment, flow port 20 enters the throughbore 6 above the
uppermost barrier, annulus mandrel 74 in the embodiment shown as
FIGS. 1A, 1B and 2. This arrangement provides advantages over prior
Christmas trees in at least certain well killing situations;
however, in other embodiments the annulus flow port 20 enters the
throughbore 6 at other locations relative to the internal barriers.
The annulus flow port 20 may comprise a first partial bore 21, a
second partial bore 23, and a channel 25 extending therebetween.
Channel 25 extends substantially longitudinally along the tree body
4.
[0046] A tubing annulus flow assembly 120, shown schematically in
FIG. 3, contains external piping 122 and at least one valve. Three
annulus valves are shown in FIG. 3, annulus master valve 124 (AMV),
annulus wing valve 126 (AWV), and annulus circulation valve 128
(ACV). The annulus valves 124, 126, 128 in tubing annulus flow
assembly 120 are generally controlled hydraulically, e.g. from the
surface through a control module. Hydraulic control lines 125 and
127 are indicated in FIG. 3. Electronically controlled valves are
an option to hydraulically controlled valves.
[0047] In the embodiment shown in FIGS. 1A-1D and 2, a countersunk
area 22 is provided to facilitate a flanged connection between
annulus flow assembly 120 and the side valve tree body 4 at the
external entry of tubing annulus flow port 20, however, other
connectors known in the art may be used. At least one seal 24 is
disposed in a groove 26 between the side valve tree body 4 and the
tubing annulus flow assembly 120 to prevent the flow of
hydrocarbons to the environment at this connection. Similar to the
production porting, other types and numbers of seals may be
provided.
[0048] In an alternate embodiment, the tubing annulus flow assembly
120 may attach to external fluid circulation lines, such as choke
and kill lines, instead of reentering the tree body 4.
[0049] FIG. 2 depicts a tubing annulus access port 30. Port 30
passes through tree body 4 from the through bore 6 below the tubing
hanger 42, which when the tree 4 is completed forms an annular
space or tubing annulus between the production tubing 50 and the
production casing 101. As can be seen in FIG. 3, tubing annulus
flow assembly 120 provides a means of fluid communication between
the tubing-by-casing annulus and the throughbore 6 above the tubing
hanger 42. Annulus valves 124, 126, and 128 provide one apparatus
for controlling flow from the tubing annulus. In addition,
crossover valve 130 and associated piping 132 provide a means for
controlling flow between the tubing annulus and the production
line. An electrical penetrator 120 as shown in FIGS. 1C and 1D may
enable the access to the tubing annulus. Although the embodiments
shown provide a well-designed apparatus for controlling flows
during circulation, bullheading, injections, and other operations
as may be required, those skilled in the art will appreciate that
various other arrangements of valves and piping can be provided to
achieve the same functions.
[0050] Additional ports or bores through the side valve tree body 4
may be included as required for hydraulic and/or electrical
connections downhole. For example, in the embodiment of FIG. 1A,
1C, and 1D, a port 32 allows a hydraulic penetrator 140 (as shown
in FIGS. 1C, 1D, and 2) to establish fluid communication to the
hydraulic control line 53 for the downhole safety valve 48 (as
shown in FIG. 3). In other embodiments, additional ports may be
included for chemical injection lines, additional hydraulic and/or
electric connections downhole, or various other purposes as
required by a specific service.
[0051] Referring now to FIG. 4, the side valve tree body 4 is shown
during installation with a tree bore protector 34 installed in the
tree. Tree bore protector 34 contains seal 36 that seals between
the bore protector and the wellhead 100. The bore protector 34 also
contains a seal assembly 38 that provides a seal between the bore
protector and the throughbore 6 above the production flow port 12.
Tree running tool 40 is shown connected to the internal running
profile 10 of tree body 4, and provides the mechanism to lock and
unlock the tree bore protector 34.
[0052] FIGS. 1D, 5A, 5B, and 6 show the tubing hanger 42 and
associated components being run into the tree body 4 on a tubing
hanger running tool 44. FIG. 6 shows the tubing hanger 42 landed in
the tree body 4, in the locked position to the left of the
centerline and in the unlocked position to the right of the
centerline.
[0053] The tubing hanger 42 provides the means for suspending
tubing into the wellbore for production of hydrocarbons. The tubing
hanger defines a longitudinal throughbore of substantially similar
inside diameter to that of the tubing, and may have any desired
inside diameter known in the industry, including standard sizes
such as 5 or 7 inches. The tubing hanger 42 is landed and suspended
in side valve tree body 4. In conjunction with tubing hanger seal
assembly 43, disposed between the tubing hanger 42 and the
throughbore 6 of the tree body 4, the vertical load of tubing
hanger 42 and its associated components are carried and transferred
at shoulder 28 within the tree body 4. Tubing hanger seal asembly
43 may comprise metal-to-metal seals or resilient seals.
[0054] Production tubing 50 is disposed at the lower end of tubing
hanger 42, and may be attached by a threaded connection as shown in
FIGS. 1C and 6, or by other means known in the art such as bolts,
pins or compression fittings. The tubing 50 extends into the well
for as great or as short a length as required by the
characteristics of the well. As shown schematically in FIG. 3 a
downhole safety valve 52 is located significantly below the tubing
hanger 42. Downhole safety valve 52 may be hydraulically controlled
by hydraulic line 53, as shown in FIG. 3, or may be electrically
controlled.
[0055] Referring again to FIG. 6, the tubing hanger running tool 44
is detachably connected at a first end to the completion riser or
drill pipe with a standard riser joint connection. At a second end,
running tool 44 is detachably connected to the tubing hanger 42. In
between, a series of slidable members 45 are sealingly disposed
between the body of tubing hanger running tool 44 and the tree body
4. Hydraulic passages 46 allow the flow of fluid to areas between
the seals, forcing the slidable members 45 to up or down
positions.
[0056] The left side of the centerline in FIG. 6 shows the tubing
hanger 42 fixedly connected to running tool 44, as during the
running procedure. Tubing hanger attachment ring 47 is engaged in a
profile in the exterior of tubing hanger 42, and is prevented from
disengaging by the slidable member 45 located adjacent. However, to
the right of the centerline it is shown that the slidable members
45 can be raised allowing the tubing hanger attachment ring 47 to
disengage from the profile, and thus allow retrieval of the running
tool 44.
[0057] Similarly, the left side of the centerline in FIG. 6 shows
the tubing hanger seal assembly 43 held in a locked position by
tubing hanger seal lock down ring 48 engaged in a profile in the
interior wall of tree body 4, and held in place by tubing hanger
seal lock down sleeve 49. To the right of the centerline, the
tubing hanger lock down sleeve 49 is raised, allowing the lock down
ring 48 to disengage.
[0058] Referring again to FIGS. 1A and 1C, fixed to tubing hanger
42 is hydraulic penetrator connection assembly 60. The hydraulic
penetrator connection assembly 60 provides for a sealing interface
along the inner surface of the tree body 4 around the hydraulic
penetrator port 32. Penetrator connection assembly 60 contains a
biased cam element 62 that moves a coupler 64 into position to form
a sealed contact with the penetrator 140. Accordingly, the tubing
hanger 42 shown is oriented to align the hydraulic penetrator 140
connect to the downhole safety valve's hydraulic control line 53.
However, the hydraulic penetrator 140 shown is not essential to the
invention. Non-oriented tubing hangers are an acceptable option
where another method of communication downhole is chosen. Hydraulic
control line 53 may be coiled as shown to absorb movement during
installation and during use.
[0059] In the embodiment shown in FIGS. 1A-1D, tubing hanger 42 is
oriented by depending sleeve 54 coupled to the lower portion of the
tubing hanger 42. An orientation key 56 is mounted on the depending
sleeve 54. Referring to FIG. 5A, during installation of the tubing
hanger 42 the orientation key 56 (not shown) on depending sleeve 54
contacts a cam surface on an orientation sleeve 58. The orientation
sleeve 58 is mounted within an isolation sleeve 59. Isolation
sleeve 59 provides seals to the production casing 101 in wellhead
100 and to the tree body 4, and provides a recess to carry the
orientation sleeve 58. Other means of orienting the tubing hanger,
such as using a pin and groove system either in a blowout preventer
or in the tree, are easily adaptable to the system as shown.
[0060] FIGS. 7A and 7B, like the left side of FIG. 6, show the
tubing hanger 42 landed and locked within the side valve tree body
4. In FIGS. 7A and 7B the tubing hanger running tool 44 is shown
still attached to the tubing hanger 42.
[0061] FIGS. 8A and 8B show the tubing hanger running tool 44
released from the tubing hanger 42. A latch ring in running tool 44
is released from the tubing hanger seal lock down ring 48 by
hydraulic pressure which moves the slidable members 45 generally
outward and upward. Similarly, tubing hanger attachment ring 47
disengages from its profile on the upper mandrel of tubing hanger
42. Accordingly, the tubing hanger running tool 44 can be removed,
leaving the tubing hanger 42 installed in the tree body 4 as shown
in FIG. 9.
[0062] Referring to FIGS. 1 and 9, the tubing hanger 42 contains a
cam profile 70. As shown in FIG. 1, the cam profile 70 may be
contained on a cylindrical insert 72 journalled within the tubing
hanger 42, or alternatively may be machined into the internal
throughbore of tubing hanger 42.
[0063] As shown in FIG. 1A, installed above the tubing hanger is an
internal tree cap flow divertor, for example an actuation mandrel
74 and plug 94. Actuation mandrel 74 is substantially coaxial with
side valve tree body 4 and exhibits a longitudinal throughbore of
substantially similar diameter to that of the production tubing.
Actuation mandrel 74 lands above the tubing hanger 42, and its
longitudinal throughbore is coextensive with the longitudinal
throughbore of the tubing hanger 42. In addition, the actuation
mandrel 74 contains a radially drilled bore 76 that allows produced
hydrocarbons to be diverted from the longitudinal throughbore.
[0064] As seen in FIG. 1, bore 76 of actuation mandrel 74 is
relatively aligned vertically and radially with flow port 12
through side valve tree body 4. In the embodiment shown this
alignment is achieved through a cam system.
[0065] Disposed at the lower end of actuation mandrel 74 is a
depending cylinder 78 which extends into the tubing hanger 42.
Depending cylinder 78, also called a sleeve, is separate from the
actuation mandrel 74, and may be bolted as shown, or attached by
other means commonly known in the art such as threaded connections,
split ring connections, etc. Seals 79 and 80 restrict or prevent
the passage of fluid between the interfaces of cylinder 78 and the
tubing hanger 42, and between the cylinder 78 and the actuation
mandrel 74 respectively. When the actuation mandrel 74 is installed
(as shown in FIGS. 1A, 10A, and 10B) a key 82 fixed to the
depending cylinder 78 interacts with the cam surface 70, causing
the actuation mandrel 74 to rotate for orientation. The degree of
precision in the rotation and orientation is a matter of design
choice, and can be as rough or precise as operating conditions
require.
[0066] In addition, embodiments are envisioned wherein the
actuation mandrel 74 is non-oriented. In such a case, produced
fluids would be routed through an annular recess similar to that
shown by reference numeral 13 but sized to permit annular flow
without overly restricting flow velocity. Gallery seals (similar to
seal 77 below the bore 76) would be installed above and below the
bore 76 forcing flow to remain in the annular groove until exiting
at the bore 76. Additional bores similar to 76 could be added to
reduce the restriction in flow caused by radial misalignment.
[0067] The outer wall of actuation mandrel 74 contains a series of
reduced diameter steps or shoulders 83 that allow for the proper
positioning, installation and landing of pack-off seals. The upper
portion of actuation mandrel 74 contains an external profile 84
that allows the tree cap to be latched to a running tool using tree
cap attachment ring 85, as shown in FIGS. 10A and 10B. Running tool
profile 84 may match the profile at the top of the tubing hanger
42, as shown more clearly in FIG. 1, to allow the use of the tubing
hanger running tool 44 for installation and removal of the
actuation mandrel 74.
[0068] Two sets of pack-off seals 86, 90 are installed externally
around the circumference of the actuation mandrel 74. In one
embodiment, as shown in FIG. 1, pack-off seal 86 comprises seal
element 87, shown as resilient seals, to restrict and prevent the
passage of produced fluids above the production bores 76 and 12 in
throughbore 6. Pack-off seal 86 is shown coupled to actuation
mandrel 74 such that the two may be run into the tree as one unit.
Referring to FIGS. 10A and 10B, before the lower pack-off seal
assembly 86 is landed, lower seal lock down ring 88 is not engaged
in the mating profile in the throughbore of tree body 4. However,
after the actuation mandrel 74 is landed and locked, as shown in
FIGS. 1A-1C, 11A, and 11B, the seal lock down ring 88 is engaged in
the profile and prevented from moving out of the profile by lower
seal lock down sleeve 89. Lower seal lock down sleeve 89 also
contains a latching profile at its upper edge to couple to the
running tool for removal of the lower seal assembly 86 as may be
required.
[0069] Referring again to FIGS. 1A-1C, upper pack-off seal assembly
90 is shown landed and locked above the lower pack-off seal 86.
Seal element 91 is shown having metal-to-metal sealing. However, it
should be noted that the sealing elements 86 and 91 of pack-off
seals 86 and 90 can be resilient, metal-to-metal, or any
combination of both. In the embodiments of FIGS. 1A-1C, upper
pack-off seal 90 is not coupled to the actuation mandrel 74, but it
is run into the tree separate from the actuation mandrel 74 and
lower pack-off seal 86. Alternatively, as shown in FIGS. 10A and
10B, pack-off seal 90 may be coupled to actuation mandrel 74 such
that the two seal assemblies 86 and 90 and the actuation mandrel 74
may be run into the tree in one trip as a combined unit. Further,
both seal assemblies 86 and 90 and the actuation mandrel 74 could
be run individually in separate trips.
[0070] Referring to FIGS. 11A and 11B, before the upper pack-off
seal assembly 90 is landed, upper seal lock down ring 92 is not
engaged in the mating profile in the throughbore of tree body 4.
However, after the actuation mandrel 74 is landed and locked, as
shown in FIGS. 11A and 11B, upper seal assembly 90 is in place and
the upper seal lock down ring 92 is engaged in profile 10. The lock
down ring 92 is prevented from moving out of the profile 10 by
upper seal lock down sleeve 93. Upper lock down sleeve 93 also
contains a latching profile at its upper edge to couple to the
running tool for removal of the upper seal assembly 90. In
preferred embodiments, the actuation mandrel 74 and the seal
assemblies 86 and 90 are coupled to run in one trip. However, the
coupling mechanism allows the independent removal of one or both
seal assemblies, such as by coupling with shear pins.
[0071] The throughbore of actuation mandrel 74 contains two plugs
94 and 96. When installed, the plugs 94 and 96 serve as redundant
barriers to prevent the flow of hydrocarbons up the longitudinal
throughbore, and to divert the flow into the bore 76. Each plug is
locked and landed in an internal profile 95 and 97. The plugs 94
and 96 may be wireline retrievable plugs, coiled tubing plugs,
valves, or other closures, and may be mechanically or hydraulically
actuated. At least the lower plug may contain hard facing to resist
damage from the production stream, and be located so as to minimize
turbulence in the production flow stream. As shown in FIG. 10A and
10B the plugs 94 and 96 may be run with the actuation mandrel 74,
however, each plug is independently retrievable. With both of plugs
94 and 96 located in the tree cap 74, an operator may
advantageously run or retrieve a tubing hanger without setting a
plug in the tubing hanger, thereby eliminating a plug-setting
trip.
[0072] FIGS. 12A and 12B show the tree cap attachment ring 85
released from the profile 84 in actuation mandrel 74 to allow the
retrieval of the running tool.
[0073] The embodiments shown in FIGS. 1A, 1C, 2 and 13 show the
christmas tree system 2 in the production mode, with the tubing
hanger 42 and the actuation mandrel 74 installed.
[0074] While the present invention has been particularly shown and
described with reference to a particular illustrative embodiment
thereof, it will be understood by those skilled in the art that
various changes in form and details may be made without departing
from the spirit and scope of the invention. The above-described
embodiment is intended to be merely illustrative, and should not be
considered as limiting the scope of the present invention.
* * * * *