U.S. patent application number 10/671357 was filed with the patent office on 2005-03-31 for radial penetrator assembly and method.
Invention is credited to Buckenham, Richard, Hall, Douglas D., Herd, David P..
Application Number | 20050067167 10/671357 |
Document ID | / |
Family ID | 34376122 |
Filed Date | 2005-03-31 |
United States Patent
Application |
20050067167 |
Kind Code |
A1 |
Hall, Douglas D. ; et
al. |
March 31, 2005 |
Radial penetrator assembly and method
Abstract
Radial penetrator assembly 10 conducts fluid through the
passageway in the wall to a wellhead housing 18 and into a port in
a tubular hanger 14 positioned within a central bore 19 in the
wellhead housing. The flexible tube 22 extends between the
passageway in the wellhead housing and the port in the inner
member, while sleeve-shaped adapter 30 extends radially from the
wellhead housing and has an adapter bore sealed to a radial
passageway in the wellhead housing. A radial outer seal 64 seals
between the radial outer portion of the adapter 30 and a radially
outer portion of the flexible tube 22. The flexibility of the tube
permits an inner portion axis with the tube to be offset or slanted
with respect to an outer portion axis of the tube.
Inventors: |
Hall, Douglas D.; (Houston,
TX) ; Herd, David P.; (Houston, TX) ;
Buckenham, Richard; (Singapore, SG) |
Correspondence
Address: |
LOREN G. HELMREICH
BROWNING BUSHMAN, P.C.
SUITE 1800
5718 WESTHEIMER
HOUSTON
TX
77057
US
|
Family ID: |
34376122 |
Appl. No.: |
10/671357 |
Filed: |
September 25, 2003 |
Current U.S.
Class: |
166/379 ;
166/305.1; 166/90.1 |
Current CPC
Class: |
E21B 33/038
20130101 |
Class at
Publication: |
166/379 ;
166/305.1; 166/090.1 |
International
Class: |
E21B 043/16 |
Claims
1. A radial penetrator assembly for sealingly conducting fluid
through the passageway in a wall of a wellhead housing having a
central bore and into a port in an inner member positioned within
the central bore of the wellhead housing, the radial penetrator
assembly comprising: a flexible tube extending radially between the
passageway in the wellhead housing and sealingly engaging the port
in the inner member; a sleeve-shaped adapter extending radially
from the wellhead housing and having an adapter bore sealed to the
passageway in the wellhead housing; and a radially outer seal
between a radially outer portion of the adapter and a radially
outer portion of the flexible tube, such that the flexibility of
the tube permits an inner portion axis of the tube to be axially
offset or slanted with respect to an outer portion axis of the
tube.
2. A radial penetrator assembly as defined in claim 1, wherein the
radially outer seal is a metal-to-metal seal between an outer
sealing surface on the flexible tube and an inner sealing surface
on the adapter.
3. A radial penetrator assembly as defined in claim 2, wherein the
inner sealing surface on the adapter is tapered for sealing with a
tapered surface on the outer seal.
4. A radial penetrator assembly as defined in claim 2, wherein the
outer sealing surface on the flexible tube is substantially
cylindrical for sealing engagement with a substantially cylindrical
inner surface on the outer seal.
5. A radial penetrator assembly as defined in claim 1, wherein the
inner member comprises a tubular hanger for suspending a tubular
string in a well, and the port in the tubular hanger is a
throughport which extends to an end surface of the tubular
hanger.
6. A radial penetrator assembly as defined in claim 1, wherein the
inner member is positioned on a landing shoulder of the wellhead
housing to be at a selected axial position within the central bore
of the wellhead housing.
7. A radial penetrator assembly as defined in claim 6, further
comprising: a radial alignment member for selectively aligning the
inner member within the central bore of the wellhead housing.
8. The radial penetrator assembly as defined in claim 1, wherein
the wellhead housing has a generally cylindrical bore.
9. A radial penetrator assembly as defined in claim 1, wherein the
inner member has a generally cylindrical outer diameter.
10. A radial penetrator assembly as defined in claim 1, wherein the
port in the inner member includes a throughport extending to an end
surface of the inner member.
11. A radial penetrator assembly as defined in claim 10, wherein an
axis of the passageway in the wellhead housing is substantially
aligned with an axis of the end port.
12. A radial penetrator assembly as defined in claim 1, wherein the
adapter bore is substantially aligned with the passageway in the
wellhead housing.
13. A radial penetrator assembly as defined in claim 1, wherein the
outer member has a generally cylindrical outer surface.
14. A radial penetrator assembly as defined in claim 1, wherein the
flexible tube has a substantially cylindrical outer surface along
substantially its axial length.
15. A radial penetrator assembly as defined in claim 1, wherein the
radially inner end of the flexible tube is removably sealed with
the inner member by an inner plug.
16. A radial penetrator assembly as defined in claim 15, wherein
the inner seal is removably secured to the inner members by
threads.
17. A radial penetrator assembly as described in claim 16, further
comprising: an outer seal for sealing between the flexible tube and
the adapter, the outer seal being removably secured to the adapter
by threads.
18. A radial penetrator assembly as defined in claim 1, wherein a
radial spacing between a radially inner end of the flexible tube
and a radially outer end of the flexible tube is in excess of about
30% greater than a radial spacing between a radially inner end of
the flexible tube and a radially outer end of the passageway in the
wall of the outer member.
19. The radial penetrator assembly as defined in claim 1, further
comprising: a flange assembly sealed to the outer housing and
having a port in fluid communication with a cavity in the cover
flange which receives an outer portion at the adapter.
20. A radial penetrator assembly for sealingly conducting fluid
through the passageway in a wall of a wellhead housing having a
generally cylindrical bore and into a port in a tubular hanger
positioned within the central bore of the wellhead housing for
suspending a tubular string in a well, the radial penetrator
assembly comprising: a flexible tube extending radially between the
passageway in the wellhead housing and the port in the inner
member; a sleeve-shaped adapter extending radially from the
wellhead housing and having an adapter bore sealed to the
passageway in the wellhead housing; a radially outer metal-to-metal
seal between a radially outer portion of the adapter and radially
outer portion of the flexible tube, such that the flexibility of
the tube permits an inner portion axis of the tube to be axially
offset or slanted with respect to an outer portion axis of the
tube.
21. A radial penetrator assembly as defined in claim 20, wherein
the tubular hanger is positioned on a landing shoulder of the
wellhead housing to be at a selected axial position within the
central bore of the wellhead housing and is rotationally aligned
with the outer member by an alignment member.
22. A radial penetrator assembly as defined in claim 21, further
comprising: a rotational alignment member for rotationally aligning
the tubular hanger within the central bore of the wellhead
housing.
23. A radial penetrator assembly as defined in claim 10, further
comprising: an outer seal for sealing with the outer sealing
surface on the flexible tube and the inner sealing surface on the
adapter
24. A radial penetrator assembly as defined in claim 23, wherein
the inner member comprises a tubular hanger for suspending a
tubular string in a well and the port in the tubing hanger is a
throughport which extends to an end surface of the tubular
hanger.
25. A radial penetrator assembly as defined in claim 23, wherein
the outer sealing surface on the flexible tube is substantially
cylindrical for sealing engagement with a substantially cylindrical
inner surface on the outer plug.
26. A radial penetrator assembly as defined in claim 20, wherein
the port in the inner member includes a throughport extending to an
end surface of the inner member.
27. A radial penetrator assembly as defined in claim 20, wherein an
axis of the passageway in the wellhead housing is substantially
aligned with an axis of the end port.
28. A radial penetrator assembly as defined in claim 20, wherein
the adapter bore is substantially aligned with the passageway in
the wellhead housing.
29. A radial penetrator assembly as defined in claim 20, wherein
the radially inner end of the flexible tube is removably sealed
with the tubular hanger by an inner seal.
30. A radial penetrator assembly as defined in claim 29, wherein
the inner seal is removably connected to the tubular hanger by
threads.
31. A radial penetrator assembly as defined in claim 29, further
comprising: an outer seal for sealing between the flexible tube and
the adapter, the outer seal being removably sealed to the adapter
by threads.
32. A radial penetrator assembly as defined in claim 20, wherein a
radial spacing between a radially inner end at the flexible tube
and a radially outer end of the flexible tube is in excess of about
30% greater than a radially spaced between a radially inner end of
the flexible tube and a radially outer end of the passageway in the
wall of the outer member.
33. A radial penetrator assembly as defined in claim 20, further
comprising: a flange removably sealed to the outer housing and
having a port in fluid communication with a cavity in the flange
which receives an outer portion of the adapter.
34. A method of sealingly conducting fluid through the passageway
in a wall of a wellhead housing having a central bore and into a
port in an inner member positioned within the central bore of the
wellhead housing, the method comprising: radially extending a
flexible tube between the passageway in the wellhead housing and
the port in the inner member; providing a sleeve-shaped adapter
extending radially from the wellhead housing and having an adapter
bore sealed to the passageway in the wellhead housing; and forming
a radially outer seal between a radially outer portion of the
adapter and radially outer portion of the flexible tube, such that
the flexibility of the tube permits an inner portion axis of the
tube to be axially offset or slanted with respect to an outer
portion axis of the tube.
35. A method as defined in claim 34, wherein the radially outer
seal is a metal-to-metal seal formed between an outer sealing
surface on the flexible tube and an inner sealing surface on the
adapter.
36. A method as defined in claim 34, wherein the inner member is
positioned on a landing shoulder of the wellhead housing to be at a
selected axial position within the central bore of the wellhead
housing.
37. A method as defined in claim 36, further comprising: providing
a rotational alignment member for rotationally aligning the inner
member within the central bore of the wellhead housing.
38. A method as defined in claim 34, further comprising: providing
an outer seal for sealing with the outer sealing surface on the
flexible tube and the inner sealing surface on the adapter.
39. A method as defined in claim 30, further comprising: tapering
the inner sealing surface on the adapter for sealing engagement
with a tapered surface on the outer seal.
40. A method as defined in claim 38, wherein the outer sealing
surface on the flexible tube is substantially cylindrical for
sealing engagement with a substantially cylindrical inner surface
on the outer seal.
41. A method as defined in claim 34, wherein an axis of the
passageway in the wellhead housing is substantially aligned with an
axis of the end port.
42. A method as defined in claim 34, wherein the radially inner end
of the flexible tube is removably sealed with the inner member by
an inner seal.
43. A method as defined in claim 34, wherein an inner seal is
removably sealed to the inner member by threads.
44. A method as defined in claim 43, further comprising: providing
an outer seal for sealing between the flexible tube and the
adapter, the outer seal being removably secured to the adapter by
threads.
45. A method as defined in claim 34, wherein a radial spacing
between a radially inner end of the flexible tube and a radially
outer end of the flexible tube is in excess of about 30% greater
than a radial spacing between a radially inner end of the flexible
tube and a radially outer end of the passageway in the wall of the
outer member.
46. A method as defined in claim 34, further comprising: removably
sealing a flange to the outer housing and having a port in fluid
communication with a cavity in the flange which receives an outer
portion of the adapter.
47. A method as defined in claim 34, wherein the port in the inner
member includes a throughport extending to an end surface of the
inner member.
48. A method as defined in claim 34, wherein test fluid is
introduced to verify holding of a selected working pressure.
Description
FIELD OF THE INVENTION
[0001] The present invention relates to a radial penetrator
assembly and, more particularly, to a radial penetrator assembly
with metal-to-metal seals and a sleeve-shaped adapter extending
radially from a wellhead housing.
BACKGROUND OF THE INVENTION
[0002] Some oilfield applications involve conducting high pressure
fluids through a tubing hanger, through a bridge across an annular
gap, then through an outer wellhead housing, such as a tubing spool
or wellhead body, with all critical seals being metal-to-metal
seals. A conduit may be attached to the inner body to seal internal
pressure within the conduit, while the opposing outer end of the
conduit may be sealed with the outer wellhead housing. However, the
two end attachments to which the conduit ends are affixed and pass
through typically possess some misalignment, either vertically or
laterally (circumferentially). Past practice has typically employed
small diameter OD, thin walled conduit tubing that could easily be
bent to compensate for any misalignment, while still maintaining
sufficient straightness to achieve the conditions necessary to
ensure that the pressure fittings could perform their sealing
functions at each end of the conduit. The conduit and fittings
extending between the hanger and the outer wellhead housing are
commonly referred to as a radial penetrator, since the fluid is
directed radially through the housing wall. Numerous patents have
been directed to radial penetrator assemblies, including U.S. Pat.
Nos. 6,047,776, 6,050,338, 6,119,773, and 6,470,971, and many of
the references cited in these patents.
[0003] For a larger diameter, thicker walled conduit, the above
methods work neither consistently nor well. It is much more
difficult to bend large diameter, thick walled tubing, which begins
to resemble small diameter pipe. Side loads sufficient to flex the
pipe sideways to complete make-up of the fittings may cause the
tube to assume an elliptical shape, which makes it difficult to
assure a reliable external seal. These side loads are also
difficult to generate manually, as required for field make-up
operations.
[0004] Past practices include making up the first end fitting
exiting from the top of a tubing hanger with a pre-bent conduit
which directs the flow to a substantially horizontal plane.
Feedthrough of continuous conduits is conventionally through the
tubing hanger axially, then the conduit may be bent and manually
fed through the wellhead wall. This fairly simplistic and reliable
operation conventionally may only be accomplished with small
diameter, thin-wall tubing with sufficient flexibility to manually
bend the lines. Passage of the bent conduit through the wellhead
wall from the outside may also require a very large port through
the wellhead wall. Substantial offsets, both vertically and
laterally, may occur and may be compensated for externally.
[0005] The disadvantage of the prior art are overcome by the
present invention, and an improved radial penetrator assembly and
method are hereinafter disclosed.
SUMMARY OF THE INVENTION
[0006] A radial penetrator assembly is provided for sealingly
conducting fluid through the passageway in a wall of a wellhead
housing having a central bore, with the fluid passing into a port
in an inner member positioned within the central bore of the
wellhead housing. The radial penetrator assembly includes a
flexible tube extending radially between the passageway in the
wellhead housing in the port and the inner member, a sleeve-shaped
adapter extending radially from a wellhead housing to an adapter
bore, sealed to the passageway in the wellhead housing, and a
radially outer seal between a radially outer portion of the adapter
and the radially outer portion of a flexible tube, such that the
flexibility of the tube permits an inner portion axis of the tube
to be axially offset or slanted with respect to an outer portion
axis of the tube. In a suitable embodiment, the radially outer seal
is a metal-to-metal seal between an outer sealing surface on the
flexible tube of the inner sealing surface on the adapter.
[0007] In one embodiment, the inner member may comprise of a
tubular hanger for suspending a tubular string in the well, and the
port in the tubular hanger and a throughport which extends to an
end surface of the tubular hanger. The radially alignment member
may be used for selectively aligning the inner member with the
central bore of the wellhead housing. A radial spacing between a
radially inner end of a flexible tube and a radially outer end of a
flexible tube preferably is in excess of about 30% greater than the
radial spacing between a radially inner end of the flexible tube
and radially outer end of the passageway in the wall of the outer
member.
[0008] A method of the invention includes radially extending the
flexible tube between the passageway and the wellhead housing and
the port in the inner member, and providing a sleeve-shaped adapter
extending radially from the wellhead housing and having an adapter
bore sealed to the passageway of the wellhead housing. The radially
outer seal is formed between a radially outer portion of the
adapter and the radially outer portion of a flexible tube, such
that the flexibility of the tube permits an inner portion axis of
the tube to be axially offset or slanted with respect to an outer
portion axis of the tube.
[0009] A particular feature of the invention involves the use of
seals such that test fluid may be introduced to verify the holding
of a selected working pressure. This test operation may be
performed at the surface, thereby providing assurance to the
operator prior to downhole installation that the system will
perform as intended.
[0010] A significant advantage of the present invention is that the
technique is relatively simple and involves highly reliable and
commercially available components.
[0011] These and further features and advantages of this invention
will become apparent from the following detailed description,
wherein reference is made to the figures in the accompanying
drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0012] FIGS. 1-6A illustrate the wellhead assembly during various
stages of installation.
[0013] FIG. 1 illustrates the wellhead housing with a tubing hanger
above a landing shoulder, prior to being sealed within the bore of
the wellhead housing.
[0014] FIGS. 2 and 3 illustrate the wellhead housing with a tubing
hanger in a subsequent stage of installation. FIG. 3A illustrates
in greater detail the radial penetrator assembly shown in FIG.
3.
[0015] FIG. 4 illustrates the wellhead housing with a tubing hanger
in another stage of installation, while FIGS. 4A and 4B illustrate
in greater detail, the radial penetrator assembly shown in FIG.
4.
[0016] FIG. 5 illustrates the radial penetrator in a wellhead
housing in another stage of installation.
[0017] FIG. 6 discloses the wellhead housing with a tubing hanger
and a pair of radial penetrators in another stage of installation,
with the penetrator shown in greater detail in FIG. 6A.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
[0018] A radial penetrator assembly as shown in detail in FIG. 5
may be used for sealingly conducting fluid through a passageway in
a wall of a wellhead housing 18, as shown in FIG. 6, with the
wellhead housing 18 conventionally having a central bore 19 and a
lower end with a flange 17 for sealing engagement with other
oilfield equipment. The radial penetrator assembly 10 as shown in
FIG. 5 extends from the wellhead housing 18 radially inward to an
entrance/egress port 15 in an inner member, such as the tubular
hanger 14 shown in FIG. 1, with a hanger 14 having a throughport
16, conventionally extending downward to one or more tubing lines
12 extending further downward through the wellhead housing 18 and
typically into the well. The interior of tubing 12 as shown in FIG.
6 is thus in sealed fluid communication with the radially outward
end 22 of the flexible tube 20, as shown in FIG. 5. The wellhead
housing 18 as shown in FIG. 1 may also have an inner cylindrical
bore 19. The tubular hanger 14, which acts as the inner member, may
have a generally cylindrical outer diameter.
[0019] The radial penetrator assembly of the present invention is
particularly suitable for providing the desired flow path between a
wellhead housing 18 and a tubular hanger for suspending a tubular
string in a well. In other embodiments, the tubular hanger may be
replaced by a plug or other inner member for landing in the central
bore of the wellhead housing 18 and having a port in general
alignment with the radial passageway in the wall of the wellhead
housing. The port may not continue through the inner member in a
downward manner as shown for the tubular hanger, and instead may
extend axially upward from the port to a top surface of the plug,
or may extend to some other surface of the inner member. Also, the
passageway in the wall of the wellhead housing may supply fluid to
a port in an inner member which has no outlet, and instead may, for
example, supply an opening pressure or a closing pressure to a
valve within the inner member 14. Also, it should be understood
that the term "wellhead housing" as used herein refers to the outer
housing or spool of oilfield equipment which has a central bore for
receiving the inner member and one or more passageways in the wall
of the outer member each for receiving the radial penetrator
assembly as disclosed herein.
[0020] A feature of the invention is that the various metal seals
required for the penetrator assembly are not formed by threads, and
instead threads are preferably used to removably attach and detach
the radial penetrator assembly from the wellhead housing and the
inner member. Also, the flexible tube which extends radially
between the wellhead housing and the throughport in the inner
member is preferably of the type which has a substantially fixed
axial length, i.e., the flexible tube itself is not constructed in
a manner such that its axial length may be easily stretched or
reduced in the manner of an elongate bellows. High reliability and
low cost are thus achieved with the uniform diameter metal flexible
tube as disclosed herein, which may be fabricated from steel,
inconel, copper, or other flexible yet high burst pressure
material.
[0021] The radial penetrator assembly as disclosed herein
preferably includes three metal-to-metal seals which allows the
assembly to be reliably installed, easily removed, then again
installed in the wellhead housing and the tubular hanger. As shown
in FIG. 5, a first, inner seal is formed by the tapered nose 21 of
tube 20 in contact with a contact seat 32 in the tubing hanger body
14. This first, inner seal is energized and retained by the
threaded gland 64. A second, radially intermediate seal, which
optionally may be supplemented by an elastomeric seal 38, seals
between the inner portion of the adapter 30 and the wellhead
housing 18. Finally, a third, outer metal-to-metal seal is
energized by a threaded gland 66, sealing between the outer end of
the adapter 30 and the outer end of the flexible tube 20. This
construction allows a cover flange 52 as shown in FIG. 6A to be
easily installed, so that fluids may be reliably transmitted
between the control or injection line 42 as shown in FIG. 6A and
the flow line 12 as shown in FIG. 6.
[0022] The tubular hanger 14 as shown in FIG. 6 includes a central
bore 24 in fluid communication with and extending above the bore 19
in the wellhead housing 18. The upper end 25 of the tubular hanger
14 as shown in FIG. 2 may be provided with one or more seals 26 for
sealing engagement with the lower end (not shown) of a tubular
spool adapter which may be stabbed over the top of the tubing
hanger and locked to the wellhead housing 18.
[0023] Those skilled in the art will appreciate that the tubing
hanger 14 as shown in FIG. 1 is shown raised from its landed
position on the wellhead housing, and has been landed on shoulder
28 of housing 18 in FIG. 2, with seals 29 providing a static seal
between an outer diameter of the tubular hanger and an inner
cylindrical bore of the wellhead housing. Once landed, the tubular
hanger may be locked axially within the wellhead housing by a
C-ring 85 which engages grooves provided in the wellhead housing.
The upper end of the wellhead housing may also include one or more
outer grooves 88 for receiving a locking member to structurally
connect with the wellhead housing 18 with a tubing spool adapter
(not shown) or other housing.
[0024] FIG. 2 illustrates a conventional threaded plug 87 secured
to the tubular hanger 14 for closing off the throughport 15 in the
hanger, and another conventional threaded plug 89 secured to the
wall of the wellhead housing to close off the radially extending
passageway 88 through the housing wall, as shown in FIG. 1. Still
referring to FIG. 2, the radial penetrator assembly as disclosed
herein conveniently accomplishes its desired goal of sealingly
conducting fluid even though the central axis 86 of the plug 87,
and thus the central axis of the throughport 15 in the tubular
hanger, is not in alignment with the central axis 90 of the plug
89, and thus the central axis of the radial passageway 88 in
wellhead housing 18.
[0025] A suitable sequence for installing the radial penetrator
assembly at the surface may thus start with the assumption that the
tubing hanger 14 has already landed on the shoulder 28 of the
wellhead housing 18 as shown in FIG. 2, and that the axis 86 of the
radially outer port in the outer surface of the tubular hanger may
not be in precise alignment with the axis 90 in the radial
passageway in the wellhead housing.
[0026] Various forms of a conventional alignment members on one of
the housing and tubing hanger may be used in cooperation with a
groove on the other of the wellhead housing and the tubing hanger
to automatically align the tubing hanger 14 within the wellhead
housing, so that the landed tubing hanger is properly positioned
when lowered onto the shoulder 28. In most cases, misalignment
between the axes 86 and 90 as shown in FIG. 2 may be slight once
the tubing hanger is properly landed on the wellhead housing.--Even
a slight misalignment may, however, make it difficult to obtain the
desired metal-to-metal seals for fluid communication between the
one or more tubes 12 and the corresponding radial passageways in
the wall of the wellhead housing 18.
[0027] Referring again to FIG. 5, the radial penetrator assembly 10
includes three primary components. Elongate flexible tube 20
preferably has a substantially uniform diameter outer surface 21
along substantially its entire length. A generally sleeve-shaped
adapter 30 is positioned within a passageway 88 of the wellhead
housing 18, extending radially from the wellhead housing 18 to an
adapter passageway 33 of the adapter 30. The seal 38 seals the
passageway 88 between the adapter 30 and the wellhead housing 18.
The flexibility of the tube 20 permits an inner portion axis 92 of
the tube 22 to be axially offset or slanted with respect to an
outer portion axis 94 of the tube 20. More particularly, a
re-sealable metal-to-metal seal is preferably obtained between an
outer sealing surface of the flexible tube 20, which preferably is
the outer substantially uniform diameter cylindrical surface 21,
and the inner sealing surface 34 on the adapter 66, which energizes
the seal. In a preferred embodiment, the inner threaded plug 64 as
shown in FIG. 5 may be threaded to the tubular hanger 14 to
energize the seal between the tapered nose 21 of the flexible 20
and the contact seat 32 in the tubing hanger body 14. The threaded
glands 64, 66 thus allow the adapter assembly to be easily
installed between the tubular hanger, but also allow the adapter
assembly to be easily removed. Thus, for example, the tubing hanger
subsequently may be raised above the wellhead housing after the
seal assembly as shown in FIG. 2 has been retracted, thereby
allowing the tubular suspended in the well from the tubing hanger
14 to be retrieved through the wellhead housing 18.
[0028] Still referring to FIG. 5, it should be understood that the
purpose of the adapter 30 is to lengthen the axial spacing between
the threaded plugs 64 and 66 from that which would conventionally
be provided if the inner plug 64 were between the inner end 65
between an outer end 22 of the tube 20 in the wellhead housing 18.
More particularly, the axial length of the adapter 30 is preferably
controlled so that a radial spacing between a radially inner end 65
of a metal tube 22 and a radially outer end 67 of the metal tube is
at least about 30% greater than the radial spacing between the
radially inner end 65 of the tube 20 and the radially outer end 95
(FIG. 3) of the passageway in the wall of the wellhead housing 18.
Adapter 30 thus results in a substantial increase in the length of
the flexible tube 70, thereby providing the flexibility between the
ends of the tube to achieve the desired sealing functions, as
disclosed herein. In most applications, this radial spacing between
the inner end of the tube will be about 30% or more, and in many
applications at least about 40%, greater than the spacing between
the end of the flexible tube and the outer end of the passageway in
the wall of the outer housing.
[0029] A tapered nose 21 of tube 20 and inner threaded gland 64 as
shown in FIG. 3A may be installed with the centerline 72 of the
threaded gland 64 aligned with the cetnerline 92 of the throughport
in the hanger 14. The threaded gland 64 may be tightened to the
desired torque using a sleeve-shaped threading tool 76 as shown in
FIG. 3A that allows a deep enough reach to perform the task.
Installation of the threaded gland 64 and the tapered nose 21 of
tube 20 may result in vertical and/or lateral (circumferential)
offset of the centerline 92 with respect tot he centerline 94, as
shown in FIG. 5. Conventional wrench flats 77 on tool 76 allow the
tool and thus the inner socket end of the tool to make-up or
break-out the threaded gland 64 from the hanger 14.
[0030] A sleeve-shaped adapter 30 as shown in FIG. 4 may then be
installed over the protruding end of the tube 20. The adaptor 30
preferably incorporates a long internal taper 36 as shown in FIG. 5
that allows easy installation over the tube 20 without generating
prohibitive bending loads, and also provides precision final
centralization of the tube 20 as it exits the adapter 30. This
feature counteracts the lateral offset and some of the angular
misalignment. The adapter 30 may then be tightened, creating a
metal seal with the outer housing 18. This static metal-to-metal
seal between the adapter 30 and the housing 18 may be supplemented
with an elastomeric, e.g., rubber O-ring seal 38, as shown in FIG.
5.
[0031] In order to allow tightening of the adapter, it may first be
necessary to apply a side load to the threaded gland 22 using an
alignment tool 82 to straighten the threaded gland into sufficient
lateral and angular alignment with the adapter 30.
[0032] As shown in FIG. 4A, an alignment tool 82 may be again
employed to correct any final angular misalignment between the
threaded gland 66 and the adapter 30 by applying a corrective side
load, as needed. As the side load is applied, simultaneously the
outer threaded gland 66 may be tightened to a desired final torque
level. The radial penetrator assembly thus forms a conduit with one
secured by threaded gland 64 to the hanger 14, and the opposing end
sealed by adapter 30 to the housing 18.
[0033] Once the penetrator assembly has been installed as shown in
FIG. 5, a cover flange 52 as shown in FIG. 6 may be installed
pressure-tight over the outer end of the penetrator assembly
protruding from the outside of the outer body, with a bore in
tubing line 12 in fluid communication with the tube 20. In one
embodiment, this flange 52 is used with an internal valve 54 as
shown in FIG. 6A communicating with the through passageway in the
tube 20 to control fluid flow to a respective line 12. The flange
52 may be used with an external conduit or tubing 42 through which
fluids may be transferred. Static seal 58 may seal the flange 52 to
the housing 18, while conventional bolts 59 allow the flange to be
easily installed and removed from the wellhead housing. The entire
flow circuit thus desirably employs metal-to-metal seals
throughout.
[0034] FIG. 6A illustrates one embodiment of the assembly in a test
configuration. An alternate embodiment may conduct the fluid
through the test flange without using an integral valve. Once the
cover flange 52 has been placed over the radial penetrator
subassembly, the flange ring gasket may be tested to verify
pressure integrity. FIG. 6A shows the adapter 30 with an O-ring
seal 100, which allows the introduction of test fluid between the
O-ring and the metal gasket 58 through test port 101 by removing
plug 102. This ensures the sealing integrity of seal 58 without
introducing test fluid into port 16 via tube 20.
[0035] The radial penetrator assembly of the present invention is
particularly suited for providing a desired fluid path between a
wellhead housing and a tubular hanger for suspending a tubular
string in a well. In other embodiments, the tubular hanger may be
replaced by some type of plug or other inner member which is landed
in the central bore of the wellhead housing and has a port in
general alignment with the radial passageway in the wall of the
wellhead housing.
[0036] The radial penetrator assembly as disclosed herein
preferably includes three metal-to-metal seals which allow the
assembly to be reliably installed, easily removed, and then again
installed between the wellhead housing and the tubular hanger: (1)
a radial inner seal energized by the gland 64 sealing between the
radially inner end of the tube 20 and the tubular hanger 14, (2) a
radially intermediate seal, which optionally may be supplemented by
an elastomeric seal, between the inner portion of the adapter 30
and the wellhead housing 18, and finally (3) a radially outer
metal-to-metal seal energized by the threaded gland 66 sealing
between the outer end of the adapter 30 and the outer end of the
flexible tube 20.
[0037] A preferred new design includes an O-ring on the body of the
adaptor or gland 30. This allows test fluid to be introduced
through the port 101 shown in FIG. 6A, thereby allowing a
verifiable demonstration that the gasket 58 holds pressure without
introducing test fluid into port 16. The user may then be shown
that the connection meets all regulations.
[0038] While preferred embodiments of the present invention have
been illustrated in detail, it is apparent that other modifications
and adaptations of the preferred embodiments will occur to those
skilled in the art. The embodiments shown and described are thus
exemplary, and various other modifications to the preferred
embodiments may be made which are within the spirit of the
invention. Accordingly, it is to be expressly understood that such
modifications and adaptations are within the scope of the present
invention, which is defined in the following claims.
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