U.S. patent number 3,732,923 [Application Number 04/679,858] was granted by the patent office on 1973-05-15 for remote underwater flowline connection.
This patent grant is currently assigned to Rockwell Manufacturing Company. Invention is credited to John H. Fowler.
United States Patent |
3,732,923 |
Fowler |
May 15, 1973 |
REMOTE UNDERWATER FLOWLINE CONNECTION
Abstract
A method and apparatus related thereto for remotely connecting
flowlines to an underwater wellhead. A connector support cradle is
mounted to a well conductor. A guide system is provided to guide
into place a remotely operable underwater tree, flowline loops, and
connector tree hub which is connected to the flowline loops. The
tree hub is guided and latched into one end of the support cradle.
Then one end of underwater flowlines attached to a flowline
connector hub is lowered with the aid of the guide system into
engagement with the opposite end of the support cradle. Finally, a
hydraulically operable connector is guided into the cradle between
the tree hub and flowline hub. Pressure is supplied to the
connector through conduits to cause the connector to sealingly
engage the hubs providing flow communication between the tree and
flowlines.
Inventors: |
Fowler; John H. (Houston,
TX) |
Assignee: |
Rockwell Manufacturing Company
(Houston, TX)
|
Family
ID: |
24728667 |
Appl.
No.: |
04/679,858 |
Filed: |
November 1, 1967 |
Current U.S.
Class: |
166/340; 166/339;
166/344; 166/347; 285/315 |
Current CPC
Class: |
E21B
43/013 (20130101) |
Current International
Class: |
E21B
43/013 (20060101); E21B 43/00 (20060101); E21b
033/035 () |
Field of
Search: |
;166/.5,.6
;285/31,32,18,10,DIG.21 ;175/7 |
References Cited
[Referenced By]
U.S. Patent Documents
Foreign Patent Documents
Other References
Rigg, A. M. et al., A Subsea Completion System For Deep Water, in
Journal of Petroleum Technology. Sept. 1966, Society of Petroleum
Engineers of AIME, pgs. 1049-1055, TN 860 J6..
|
Primary Examiner: Champion; Marvin A.
Assistant Examiner: Favreau; Richard E.
Claims
I claim:
1. A method of connecting an underwater flowline to a tree assembly
positioned in a wellhead near the floor of a body of water, said
tree assembly having a flow connection thereon, said method
comprising the steps of:
independently of said tree assembly, guiding connector means
through said body of water into a space between one end of said
flowline and said flow connection, said one end of said flowline
and said flow connection being in coaxial alignment and
remotely causing said connector means to engage said flowline and
said flow connection for fluidtight flow communication therebetween
without disturbing the position of said flowline and said flow
connection.
2. The method of claim 1 in which said tree assembly is remotely
guided through said body of water and positioned in said wellhead
independently of said flowline.
3. The method of claim 1 in which said flowline is guided through
said body of water independently of said tree assembly and
positioned for nonengaging alignment with said flow connection
independently of said tree assembly.
4. A method of connecting an underwater production wellhead
positioned near the floor of a body of water to an underwater
production flowline comprising,
providing a first flow connection means on said production
wellhead,
providing a second flow connection means on said underwater
production flowline in coaxial alignment with said first flow
connection means,
remotely guiding from above the surface of said body of water,
flowline connector means down through said body of water into close
proximity with said first and second flow connection means, and
remotely engaging said first and second flow connection means with
said flowline connector means in fluidtight flow communication
therebetween without disturbing the position of said first and
second flow connection means.
5. The method of claim 4 in which said flowline connector means is
guided down through said body of water along a guide connection
established between said wellhead and the space above the surface
of said body of water.
6. The method of claim 4 in which said engagement of said first and
said second flow connection means is accomplished through
telescopic expansion of a portion of said connector means.
7. A method of installing production equipment at an underwater
wellhead positioned near the ocean floor, said method
comprising,
guiding a production tree assembly down through a body of water
into register with an underwater wellhead, said tree having a fluid
flowline connection thereon,
seating said production tree assembly on and securing it to said
underwater wellhead,
remotely guiding, from above the surface of the water, the end of
an underwater production flow-line down through said body of water
and securing said end near to said underwater wellhead in coaxial
alignment with the end of said fluid flowline connection,
remotely guiding, from above the surface of the water, flowline
connector means down through said body of water into close
proximity with said fluid flowline connection and said end of an
underwater production flowline, and
remotely causing said connector means to telescopically engage said
fluid flowline connection and said end of an underwater flowline
without disturbing the position of either and providing fluidtight
flow communication therebetween.
8. A method of installing production equipment at an underwater
wellhead positioned near the ocean floor, said method
comprising,
establishing a guide connection between said wellhead and the space
above the surface of a body of water along which equipment may be
guided to said wellhead,
guiding a production tree assembly down through said body of water
along said guide connection into register with said wellhead, said
production tree having a fluid flowline connection extending
therefrom,
seating said production tree assembly on and securing it to said
underwater wellhead,
guiding the end of an underwater production flow-line along said
guide connection and securing it in close proximity with and in
coaxial alignment with said fluid flowline connection,
guiding flowline connector means along said guide connection into
close proximity with said fluid flowline connection and said end of
an underwater production flowline, and
through remote means, engaging said flowline connection and said
end of an underwater production flowline with said connector for
fluidtight flow communication therebetween without disturbing the
position of said flowline connection or said end of an underwater
production flowline.
9. The method of claim 8 in which said engagement of said flowline
connection and said production flowline end is accomplished through
telescopic expansion of said connector means.
10. A method of installing an underwater flowline for connection to
an underwater production wellhead positioned near the floor of a
body of water comprising,
establishing a guide connection between said wellhead and the space
above the surface of said body of water,
affixing, above the surface of said water, connection means to the
end of a flowline,
guiding said flowline and said connection means down through said
body of water along said guide connection into register with
support means fixed at said wellhead, said support means acting as
a fulcrum on which a portion of said connection means comes to
rest,
applying a downward force to the end of said connection means to
cause it to pivot on said fulcrum into fixed engagement with said
support means,
guiding a flowline connector down through said body of water along
said guide connection into register with said connection means and
flow exit means extending from said underwater production wellhead,
and
remotely engaging said connection means and said flow exit means
with said flowline connector for fluidtight flow communication
therebetween and without altering the relative positions of said
connection means, and said flow exit means.
11. The method of claim 10 wherein said downward force is applied
through a string of pipe other than said flowline passing from
above the surface of said body of water downwardly to said
connection means.
12. The method of claim 10 wherein said guiding and said engagement
of said connection means is accomplished through remotely operable
means, said remotely operable means being remotely disengageable
and reengageable with said connection means for subsequent removal
thereof.
13. The method of claim 10 wherein sections of said flowline are
coupled together by flexible means to reduce the magnitude of said
downward force applied to the end of said connection means.
14. The method of claim 13 in which said flexible means comprises
ball and socket joint means, said ball means and socket means being
non-axially rotatable with respect to each other.
15. A method of removing production equipment from an underwater
well which includes a production tree assembly with a fluid
flowline connection thereon, an underwater production flowline, and
flowline connector means providing fluidtight flow communication
between said fluid flowline connection and one end of said
production flowline which are in coaxial alignment, said method
comprising the steps of,
remotely disengaging said connector means from said fluid flowline
connection and said production flowline without disturbing the
position of either, and
independently of said tree assembly and said flowline, raising said
connector means to the space above a body of water.
16. The method of claim 15 and the additional steps of,
detaching said production tree assembly from said underwater well,
and
independently of said flowline, raising said production tree
assembly to the space above said body of water.
17. The method of claim 15 and the additional step of,
independently of said production tree assembly, raising said
flowline to the space above said body of water for replacement,
removal, or repair thereof.
18. The method of claim 15 and the additional steps of,
remotely guiding said connector means back down through said body
of water into the space vacated by said connector means on its
removal, and
reengaging said flowline connection and said production flowline
with said connector means in fluidtight flow communication
therebetween and with disturbing the position of either.
19. Apparatus for remotely connecting the ends of a pair of
conduits submerged within a body of water for fluidtight flow
communication therebetween, said apparatus comprising
first connection means connected to the end of one of said
conduits,
second connection means connected to the end of the other of said
conduits and in fixed coaxial spaced relationship with said first
connection means, and
connector means adapted to be lowered through said body of water
between the ends of said first and second connection means and in
juxtapositional relationship therewith, said connector means
comprising engagement means adapted for remote operation to engage
said first and second connection means for fluidtight flow
communication therebetween without disturbing said fixed spaced
relationship.
20. The apparatus of claim 19, and
guide means in fixed relationship with said first and second
connection means engageable with said connector means to guide said
connector means from above said body of water to said
juxtapositional relationship with said connection means.
21. The apparatus of claim 19 in which a portion of said engagement
means is telescopically extendable to engage said connection means
in said fluidtight flow communication therewith.
22. The apparatus of claim 19 and a remote power source
communicable with said connector means for remote operation
thereof.
23. Apparatus for remotely coupling the ends of a pair of conduits
submerged in a body of water, said apparatus comprising,
guide means stationarily fixed near the floor of said body of water
and extending upwardly to the space above said body of water,
first coupling means secured to the end of one of said
conduits,
second coupling means secured to the end of the other of said
conduits and in coaxial alignment with said first coupling
means,
connector means engageable with said guide means and adapted to be
lowered from above said body of water to a point in juxtaposition
with said first and second coupling means, said connector means
comprising slidable engagement means, remotely operable to engage
said first and second coupling means for fluidtight flow
communication therebetween without disturbing the relative
positions of said first and second coupling means.
24. The apparatus of claim 23 in which said connector means
comprises flow passage means slidably received within a portion of
said connector means for extension to sealingly engage other
passage means in said first and second coupling means so that
fluidtight flow communication exists between said pair of
conduits.
25. The apparatus of claim 23 in which said engagement means
comprises latch means adapted to engage said first and second
coupling means, said latch means lying within the minimum distance
between said coupling means before said engagement and being
extendable on said engagement to contact a portion of said first
and second coupling means in disengageable engagement
therewith.
26. The apparatus of claim 23 and
remote power means connected to said connector to move said
engagement means into said contact with said first and second
coupling means.
27. Apparatus for remotely connecting underwater production
equipment to a wellhead submerged in a body of water, said
apparatus comprising,
guide means affixed to said wellhead and extending upwardly through
said body of water to a working position above said body of
water,
production tree means engageable with said guide means and adapted
to be guided thereby into register with said wellhead, said tree
means comprising flow exit means,
connection means affixed to said tree means and said wellhead for
remote connection thereof in fluid flow relationship
therebetween,
first coupling means affixed to said flow exit means,
second coupling means attached to one end of an underwater
flowline, said second coupling means being engageable with said
guide means and adapted to be lowered into stationary
juxtapositional relationship with said first coupling means with a
space therebetween,
flowline connector means engageable with said guide means and
adapted to be guided thereby into said space independently of said
flowline, said connector means being remotely operable for engaging
said first and second coupling means in fluidtight flow
communication therebetween and without disturbing the stationary
juxtapositional relationship between said first and second coupling
means.
28. The apparatus of claim 27 in which said first and second
coupling means comprise hub-like means with flow passages
therethrough and flange means on the adjacent ends of each coupling
means.
29. The apparatus of claim 28 in which said connector means
comprises passage means and latch means slidably mounted in a
portion of said connector means for engagement with said coupling
flange means.
30. Apparatus for connecting an underwater flowline to a wellhead
with flow exit means submerged in a body of water, said apparatus
comprising
support means affixed near the floor of said body of water in fixed
relationship with said wellhead,
first coupling means connected in flow relationship with said flow
exit means and supported by said support means
second coupling means connected to one end of said underwater
flowline in flow relationship therewith, said second coupling means
and said flowline end being adapted for lowering through said body
of water to a position whereby at least one end of said second
coupling means contacts a portion of said support means at a
contact point thereon,
said second coupling means and said flowline end being adapted to
pivot about said contact point into coaxial alignment with said
first coupling means leaving a space therebetween, and
coupling connector means adapted to be remotely lowered through
said body of water independently of said first and second coupling
means into said space to provide fluidtight flow communication
therebetween.
31. The apparatus of claim 30 in which said coupling connector
comprises flow means telescopically mounted therein, said flow
means being adapted to extendably engage in sealing flow
relationship flow passages in said first and second coupling
means.
32. The apparatus of claim 30 in which said coupling connector
means comprises engagement means slidingly retained in a portion of
said connector means, said engagement means being adapted for
remote operation to engage a portion of said first and second
coupling means.
33. The apparatus of claim 32 in which said engagement means
comprises cylinder and piston means, pressure operable to cooperate
with said engagement means for said remote operation to engage said
first and second coupling means.
34. The apparatus of claim 31 in which said coupling connector
means comprises pressure operable cylinder and piston means
cooperating with said flow means to extendably engage said flow
passages in said first and second coupling means.
35. Apparatus for connecting an underwater flowline to flow exit
means in a wellhead submerged in a body of water, said apparatus
comprising
first coupling means connected to said flow exit means stationarily
fixed near said wellhead,
second coupling means connected to the end of said flowline, said
second coupling means being adapted for lowering through said body
of water into a stationary position co-axially aligned with said
first coupling means with a space therebetween,
coupling connector means adapted to be remotely lowered through
said body of water independently of said first and second coupling
means into said space, said connector means having flow passages
therethrough and engagement means adapted for remote operation from
a retracted position to a position engaging said first and second
coupling means for fluidtight flow communication therebetween.
36. The apparatus of claim 35 in which said flowline comprises pipe
sections connected by flexible joints to reduce the resistance to
said co-axial alignment of said first and second coupling
means.
37. The apparatus of claim 36 in which said flexible joints are
adapted to prevent axial rotation of adjacent pipe sections
relative to each other.
38. The apparatus of claim 37 in which said flexible joints
comprise limiting means to limit co-axial disalignment of adjacent
said pipe sections to a degree small enough to permit passage of
in-line flow tools.
39. The apparatus of claim 37 in which said joint comprises ball
and socket means.
40. The apparatus of claim 39 in which said ball and socket means
comprise cooperating key and key slot means to prevent said
relative axial rotation of said adjacent joints.
41. Apparatus for remotely connecting an underwater wellhead to an
underwater flowline in a body of water, said apparatus
comprising,
flow exit means connected to said wellhead,
first coupling means connected to said flow exit means,
second coupling means connected to one end of said flowline, said
coupling means and end of said flowline being adapted for lowering
through said body of water into a predetermined position relative
to said first coupling means with a space therebetween,
connector means adapted to be lowered through said body of water
independently of said first and second coupling means into said
space between said coupling means, said connector means having flow
passage means therethrough and engagement means thereon, said
engagement means being remotely operable to engage a portion of
each of said coupling means for fluidtight flow communication
therebetween, without altering said space between said coupling
means.
42. The apparatus of claim 41 in which said engagement means is
adapted for remote disengagement from said coupling means, without
disturbing their positions, and for removal from said body of water
independent of said first and second coupling means.
43. The apparatus of claim 41 in which said connector means
comprises cylinder means and piston means reciprocally mounted
therein, said cylinder means being connected to a pressure source
to translate operating movement of said engagement means through
said piston means.
44. The apparatus of claim 43 in which said second coupling means
and said end of flowline are adapted for remote removal from said
body of water independent of said first coupling means.
45. Apparatus for remotely connecting an underwater flowline to
flow exit means in a wellhead submerged in a body of water, said
apparatus comprising
first coupling means connected in flow relationship with said flow
exit means in a stationary position;
second coupling means connected to one end of said underwater
flowline in flow relationship therewith, said second coupling means
and said flowline end being adapted for lowering through said body
of water to a position of support in close proximity with said
first coupling means,
pivot means affixed at said support position, said second coupling
means and said end of said flowline being adapted to pivot about
said pivot means into coaxial alignment with said first coupling
means, and
connector means independently lowerable from above said body of
water to a position between the ends of said first and second
coupling means, said connector means being remotely operable to
engage the ends of said first and second coupling means for
fluidtight flow communication therebetween without altering the
said stationary position of said first coupling means.
46. The apparatus of claim 45 and
force transmitting means engageable with said second coupling means
and said end of said flowline for said pivoting thereof.
47. The apparatus of claim 45 in which said flowline comprises pipe
sections connected by flexible joints to reduce the resistance of
said co-axial alignment of said second coupling means.
48. The apparatus of claim 49 in which said flexible joints
comprise ball and socket means adapted to limit co-axial
non-alignment of adjacent said pipe sections to an amount small
enough to allow passage of in-line flow tools.
49. The apparatus of claim 47 in which said flexible joints are
adapted to prevent axial rotation of adjacent pipe sections
relative to each other.
50. The apparatus of claim 49 in which said flexible joints
comprise ball and socket means, said ball and socket means being
provided with key and key slot means for said prevention of
relative axial rotation of said adjacent pipe sections.
Description
BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates to petroleum production methods and
apparatus and more particularly to methods and apparatus for
remotely connecting underwater flowlines to underwater production
trees.
2. Description of the Prior Art
Underwater drilling for oil and gas has been practiced for a good
many years. However, completing these wells with an underwater
wellhead assembly near the ocean floor has become common only in
the past few years. Underwater wellhead assemblies offer the
advantage of safety from collision by oceangoing vessels and from
damage by hurricanes, high winds, and ocean currents.
However, underwater well completions present many problems. One
such problem is the connection of production flowlines to the
underwater production tree. Until recently this was accomplished by
divers. However, divers are limited to relatively shallow water.
Such installations require diver assistance any time it becomes
necessary to pull the production tree or to disconnect the flowline
for any other reason.
The desire to drill in deeper water and to operate without diver
assistance has led to development of remotely operable underwater
connectors such as the one disclosed in U.S. Pat. No. 3,233,666.
These connectors allow remote connection and separation of
flowlines and production trees.
Generally these connectors are hydraulically or pneumatically
engageable devices affixed to the production tree which is also
remotely engaged in the wellhead. As is the case in any piece of
equipment with working parts, occasionally the connectors
malfunction and require removal for repair. With the presently
known connectors, this requires the removal of the production tree
also, which is quite a costly operation.
It is also quite difficult to design a connector for easy handling
of the flowlines during connection operations. Since the flowlines
tend to lay rigidly along the ocean floor they exert large forces
at their ends when the ends are raised or lowered in the water.
This presents difficult alignment problems for the connectors
presently in use.
SUMMARY OF THE INVENTION
The present invention presents methods and apparatus for remotely
connecting underwater flowlines to an underwater wellhead
independent of wellhead and flowline installation. In the present
invention support means for connection equipment is lowered along
with the well conductor casing in the initial drilling stages. The
wellhead, production tree and flow loops attached to a connection
hub are remotely guided and lowered into place and installed as
completion progresses. Then the ends of flowlines attached to
another connection hub are remotely lowered into position in the
support means. A special tool permits a downward force to be
applied at such a point in relationship to the flowline ends so
that the moment produced by flowline weight is counterbalanced for
easier alignment and attachment to the support means leaving a
space between the end of the flowline hub and the end of the flow
loop or tree hub. Finally a connector is remotely lowered into this
space and actuated from a remote power source to engage both hubs
providing fluidtight flow communication between the flow loops and
flowlines.
All of the connection parts which are normally susceptible to
malfunction are contained in the connector. Thus, if necessary, the
connector, independently of the flowlines and wellhead, may be
remotely disengaged and removed for inspection, repair, or
replacement. In addition, the production tree and other wellhead
equipment may be removed or worked on without disturbing the
flowline or vice versa.
The present invention therefore, incorporates the advantages of
remote flowline connection without the usual disadvantages of
removing either or both the production tree and flowline when
connector repair is necessary. It also allows independent placement
and removal of both the production tree and flowlines without
disturbing the other.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a schematic view of an underwater wellhead connected to
underwater flowlines by a connector in accordance with one
embodiment of the invention;
FIG. 2 is a cut-away perspective view of one embodiment of support
means utilized in the invention;
FIG. 3 is a vertical sectional view of a latch means employed in
the invention;
FIG. 4 is a top plan view of a flowline hub which may be used in
the present invention;
FIG. 5 is a vertical sectional view of the hub shown in FIG. 4
taken along lines 5--5;
FIG. 6 is a vertical elevational view of the right end of the hub
shown in FIG. 5;
FIG. 7 is a representative sectional view of the hub of FIGS. 4 and
5 taken along line 7--7 of FIG. 5;
FIG. 8 is a perspective view of one embodiment of a guide frame
which may be used in the installation of the present invention;
FIG. 9A is an elevational view of the guide frame of FIG. 8
connected to a running tool and a flowline hub similar to the hub
shown in FIG. 4;
FIG. 9B is an elevational view in section of a flowline joint which
may be used in the present invention;
FIG. 9C is a vertical cross section of the joint shown in FIG.
9B;
FIG. 10 is a detailed vertical section of the running tool shown in
FIG. 9A;
FIG. 11 is a vertical end view of the tool of FIG. 10 shown in its
relationship with a flowline hub and latch means;
FIG. 12 is a vertical section view of a joint to be connected
between a running string and the guide frame of FIG. 9A;
FIG. 13 is an elevational view of the guide frame of FIGS. 8 and 9A
connected to one embodiment of a flowline connector of the
invention;
FIG. 14 is an exploded perspective view of one embodiment of a
flowline connector for use in the invention;
FIG. 15A is a top view, partially in section, of the flowline
connector of FIG. 14 shown in a disengaged position;
FIG. 15B is a top view in section of the righthand portion of the
flowline connector shown in FIG. 15A in a partially engaged
position;
FIG. 15C is a top view similar to FIG. 15B showing the connector in
a fully engaged position;
FIG. 16 is a vertical section of a portion of the flowline
connector, running neck, and tool of FIG. 13 taken along line
16--16 of FIG. 13; and
FIG. 17 is an elevational view of a portion of the running neck and
tool of FIG. 16 taken along line 17--17 thereof.
DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring first to FIG. 1, an underwater wellhead and related
equipment is shown for well completion near the ocean floor 1. A
conductor casing 2 is shown with a support base 3 welded thereto.
Guide columns 4, firmly affixed to support base 3, extend upwardly
from base 3, their axes being parallel to the axis of the well
bore. Guide cables 5, attached to the ends of guide columns 4,
extend to the surface (not shown) where they are attached to a
floating platform during drilling, completion, or work-over
operations. After completion of the well, cables 5 may be removed
or buoyed for future use. If removed they may be reinstalled for
future use.
A production tree, designated generally at 10, is shown lowered
into position and remotely connected to the well by remote wellhead
connection means 20. Several remote wellhead connection means are
available. One is described in U.S. Pat. No. 3,186,486. To guide
the tree 10 and connection means 20 into position, guide tubes 21
are connected by structural supports 22 to connection means 20.
Cables 5 pass through the tubes 21 and initially guide the tree 10
and connection means 20 as they are lowered toward the ocean floor.
Bell bottoms 23 provide final alignment as tubes 21 engage guide
columns 4. The upper ends of tubes 21 are tapered inwardly to
accommodate means for guiding other equipment to be subsequently
described.
Production tree 10, as shown, is a dual completion tree. A single
completion or other multiple completion may just as easily be
performed with the present invention, the dual tree being used only
for description purposes. Production tree 10 includes master valves
11, swab valves 12, diverter valves 13, and a valve selector 14
which is connected to a remote control station to control operation
of the various valves shown. A valve selector suitable for such use
is described in copending patent application U.S. Ser. No. 587,892
filled by John H. Fowler and David P. Herd on Oct. 19, 1966, and
assigned to the assignee of the present application.
Connected to the dual strings of production tree 10 are flow loops
25 with wye valves 26 and cross over valve 27. Cross over valve 27
is normally closed. However, during "pigging" operations to clean
out flowlines it may be opened to allow reversal of flow in flow
loops 25 so a "pig" which has entered the flow loops may be
returned to its launching point on shore.
Welded to support base 3 is connector support cradle 30 which is
naturally lowered into place along with support base 3 and
conductor 2 during the early stages of drilling. Supported by
cradle 30 is connector tree hub 31, connector flowline hub 32, and
flowline connector 33. Flow loops 25 terminate in a threaded
connection with tree hub 31. Connected to flowline hub 32 are
flowlines 35 which are run to production collection facilities on
shore or at a platform some distance away. Connector 33 and hubs 31
and 32 provide flow communication between flowlines 35 and flow
loops 25. The cradle 30, hubs 31, 32, and connector 33 comprise the
flowline connection means which will be described in more
detail.
Referring also now to FIG. 2, a perspective cutout view of the
connector support cradle 30 is shown. Base rails 51 and bed plate
52 make up the lower framework. A pair of vertical hub yoke pieces
53 are spaced apart and attached at each end of the cradle to rails
51. A rectangular slot 54 open at the upper end is cut in each yoke
piece. Inclined surfaces 55 connect the vertical sides of slot 54
to the upper edge 56 of the yoke pieces. A pair of vertical
connector yoke pieces 61 are spaced apart and attached to rails 51
and plate 52. A semicircular cutout presents an upwardly facing
curved surface 62. The inner edge of surface 62 is beveled at 63.
Lying midway between yokes 61 are channel guide pieces 65, one
extending upwardly from each rail 51. Angle iron braces 66, 67, and
68 provide rigidity to the whole cradle assembly. Two hub latch
housings 70 are attached to each hub yoke, one on each side of the
cradle facing each other. Metal plates 69 are welded to inclined
surfaces 55 to protect the latch housings 70, and to aid in guiding
hubs 31 and 32 (FIG. 1) into place within cradle 30.
FIG. 3 is a detail of the entire hub latch assembly to be mounted
in latch housings 70. A portion of hub yoke 53 is shown with latch
housing 70 in section. The interior of housing 70 is cylindrical
and receives helical spring 71, cylindrical latch shaft 72 and
thrust ring 73. Attached to the outwardly facing ends of housing 70
is plate 74 which has a hole slightly larger than the diameter of
shaft 72 and concentric therewith. Shaft 72 projects through
another hole in the inward face of housing 70. O-rings 75, 76, 77
seal the interior of housing 70 against the underwater environment
to which it will be subjected. The end of shaft 72 is provided with
a latch key 78 which has an upwardly facing inclined surface 79. In
its innermost position, key 78 lies within the projection of slot
54. A rectangular object lowered into slot 54 will contact inclined
surface 79 causing key 78 to move back toward housing 70 against
the force of spring 71. After the object downwardly passes key 78,
shaft 72 will spring back, locking the object into place by virtue
of horizontal surface 80. The bottom edge of key 78 has a slight
lip bevel 80a to aid in removal of the latched in object on camming
key 78 out of engagement as will be more fully understood
hereafter.
Referring now also to FIGS. 4, 5, 6 and 7 flowline hub 32 will be
described. FIG. 4 is a top view of the hub 32. It has cylindrical
end portions 81 and 82 connected by a generally square cross
section portion 83. Tapped holes 84 are provided for connection of
a running and pulling tool to be subsequently described.
From FIG. 5, a sectional view, it can be seen that four identical
guide slots indicated generally at 85 are machined, two each at the
junctions of portions 81 and 83 and portions 82 and 83. These slots
are formed by dihedral surfaces 86, 87 and 88. (See FIG. 6 also).
Guide slots 85 aid in guiding and aligning hub 32 into one pair of
hub yokes 53 of cradle 30 (See FIG. 2) which will be better
understood subsequently.
Dual flow bores 90 and dual hydraulic fluid bores 91 pass
longitudinally through the entire length of hub 32. Looking now at
FIG. 7, bores 90 and 91 terminate in connection threads 92 and 93
on the outboard end of hub 32. At the inboard end they terminate in
counterbores 94 and 95. The opening of each counterbore 94 and 95
is beveled at 96 and 97. Cylindrical portion 81 has an integral
locking flange 98 and a frustoconical sealing ring counterbore 99
which communicates with counterbores 94 and 95.
Tree hub 31 (FIG. 1) is a mirror image of flowline hub 32. To
install tree hub 31 it would be lowered along with the production
tree 10, flow loops 25 being connected to the threads on the
inboard side (similar to threads 92 described in flowline hub 32).
Tree hub 31 can be rigidly attached at the proper location to tree
10 so that it can be guided into cradle 30 and positioned in
rectangular slots 54 of the pair of hub yoke pieces 53 (See FIG. 2)
nearest the well bore at the same time remote connection means 20
engages the wellhead. The guide system including columns 4, tubes
51 and cables 5 provide initial alignment. Final alignment is
accomplished by means including the dihedral surfaces 86, 87, 88 of
guide slots 85 (FIGS. 4, 5 and 6). If desired, hub 31 will be
latched in the cradle by the latch assembly affixed to the yoke
pieces 53 or rigidly attached to the well conductor and base.
The installation of flowline hub 32 requires a special guide frame
100, a perspective view of which is shown in FIG. 8. It includes a
triangular frame 101, guide tubes 102 with bell bottoms 103, a box
104 with a fixed cylindrical passageway 105 therethrough and a
running string connection cylinder 106.
In FIG. 9A, an elevational view partially in section, guide frame
100 and running and pulling tool 120 are shown with flowline hub 32
seated in the outboard pair of yoke pieces 53 of support cradle 30
(FIG. 2). Flowlines 35 are connected to hub 32.
To install hub 32, guide tubes 102 are placed at the water surface
around the two cables 5 which are attached to guide columns 4
nearest cradle 30 (FIG. 1). A running pipe string 107 is connected
to cylinder 106 by tool joint 110, to be more fully described
subsequently. Running and pulling tool 120 is attached to cylinder
106 at joint 109. Flowline hub 32 is connected to tool 120, which
will be more fully described later. Flowlines 35 are connected to
hub 32. The whole assembly is then lowered by running string 107
toward the wellhead and support cradle 30. The lowering of
flowlines 35 must be coordinated with this operation and may be
done from pipeline lay barges or from the drilling vessel itself by
use of a plurality of ball joints, to be described later, to impart
flexibility to the lines. As the whole assembly descends it is
guided by guide tubes 102, cables 5, and running string 107.
Nearing bottom, bell bottoms 103 guide tubes 102 onto guide tubes
21. Flowline hub 32 begins to enter yoke pieces 53 and is guided
into final alignment by inclined surface 55 and the dihedral
surfaces 86, 87, 88 of guide slots 85 in the bottom of the hub (See
FIGS. 4, 5, and 6). Since flowlines 35 are exerting a downward
force on the right end of hub 32 (as viewed in FIG. 1) there is a
tendency to prevent the left end from properly seating in yoke
piece 53. However, since running string 107 is offset to the left
end of hub 32 a downward force may be exerted to counterbalance the
moment exerted by these flowlines. If the hub 32 is not properly
aligned this force may cause it to pivot at a contact point on
outer yoke 53 into alignment. When hub 32 is properly seated the
latching means 70 attached to yokes 53 snap into place locking hub
32 into the cradle (See FIG. 3). Tool 120 may then be released and
removed along with guide frame 100 by raising running string
107.
To reduce the resistance to alignment caused by the moment exerted
by the weight of flowline 35 a flexible joint may be used between
flowline sections. A suitable joint is shown in FIG. 9B. The joint
comprises three basic parts, socket 185, ball 190, and socket
coupling 195.
Socket 185 is provided with threads 186 for connection to a
flowline section and external threads 187 for connection to
coupling 195. The internal face of joint 185 is machined with a
spherically shaped band 188 for mating with ball 190. Lying
intermediate of band 188 and cylindrical flow passage 189 is
frustoconical surface 189a to allow passage of in-line tools, which
may be sent through flowlines from time to time, even though the
axes of ball 190 and socket 185 are not concentrically aligned.
Connecting spherical band 188 and surface 189a is a series of
radial key slots 188a which may be formed by milling into an
annular shoulder 188b and cylindrical band 188c (See FIG. 9C).
Ball 190 has threads 191 for connection to a flowline joint, flow
passage 192 and a spherical ball 193 on its inner end. Flow passage
192 enlarges through frustoconical portions 192a and 192b through
the interior of ball 193 to cooperate with surface 189a of socket
185 in allowing tool passage during nonalignment. A portion of
spherical ball 193 mates with socket surface 188, O-ring seal 194
assuring a fluid tight sliding joint. Milling out radial slots 193a
between surface 192b and the exterior of spherical ball 193
provides ball 193 with keys which mate with key slots 188a of
socket 185 to prevent relative axial rotation of ball 190 with
respect to socket 185. This facilitates the operation of screwing
the ball joint onto joints of flowline, and decreases the tendency
for coupling 195 to work loose. Although the mating keys and key
slots of ball 190 and socket 185 prevent axial rotation they do not
prevent angular disalignment. Thus, the force required to pivot hub
32 and the ends of flowlines 35 about the support yoke is
substantially reduced.
Coupling 195, threaded at 196 to connect to socket 185 and provided
with spherical surface at 197, couples all joint pieces together.
Frustoconical surface 198, which has a taper of 5.degree. in one
preferred embodiment, limits the deflection of the joint to
5.degree. to assure passage of in-line tools. O-rings 199 along
with ball O-rings 194 and 194b assure a fluidtight sliding
junction. A lubricating port 195a allows joint lubrication and
packing for trouble-free service.
To fully understand tool 120, reference is now made also to FIGS.
10 and 11 which show the tool connected to hub 32 in position
within yoke pieces 53. Tool 120 is generally cylindrical in shape.
It has a cylindrical interior 121 into which a fishing neck 122
projects through a vertical hole 123 on its lower side. Fishing
neck 122 is cylindrical and is attached by flange 124 and bolts 125
to hub 32. The tapped holes 84 for bolts 125 are shown in FIG. 4.
Passing horizontally through neck 122 perpendicular to the axis of
hub 32 is a cylindrical pin 126 which projects out of each side of
neck 122. To allow pin 126 to enter tool 120, vertical slots 127
are machined on interior 121. A frustoconical surface 128 on neck
122 and the upper interior of tool 120 is provided to allow passage
of debris which might prevent proper seating of neck 122 in tool
120.
Neck 122 is held in tool 120 by a piston assembly which includes
piston 130, rod 131, circular plate 132, and fork 133. "U" shaped
fork 133 which is attached to plate 132 has a pair of horizontal
prongs which pass around neck 122 under the projecting ends of pin
126 to lock hub 32 to tool 120. Piston 130 operates in cylinder 134
to move fork 133 in and out of engagement with neck 122. In the
position shown fork 133 is fully engaged. To move the fork and hold
it in this position fluid pressure is supplied to cylinder 134
through conduit 135 which forces piston 130 to the right as shown.
To disengage tool 120 pressure is applied on the rod side of piston
130 through conduit 136 causing the fork 133 to move to the left,
freeing tool 120 to move upwardly from neck 122. Cylinder 134 is
closed by annular plug 137. O-rings 138 are provided at necessary
sealing points.
A yoke rest 140 provides a support for the left end of tool 120.
Latch retractors 141 may be provided on the bottom of tool 120 just
inside yoke pieces 53 to cam key 78 of the latching means, mounted
in enclosures 70, out of engagement with hub 32. Normally,
retractors 141 are only used when hub 32 is being removed and would
not be installed during running operations.
Connection elbow 142 and collar 143 are nonrotatingly connected
through joint 109 (See FIG. 9A) to the guide frame 100. The axis of
collar 143 is the direction of force applied through the running
string to counterbalance the moment resulting from the weight of
the flowline at the outboard end of hub 32.
Tool joint 110 (See FIG. 9A) can be more fully understood with
reference to FIG. 12, which shows the joint 110 connected to guide
frame cylinder 106. Tool joint 110 is made up of an upper
cylindrical portion 150, an intermediate cylindrical portion 151,
and a lower cylindrical portion 152 of decreasing diameters. Upper
portion 150 is provided with means such as internal threads 154 for
connection to running string 107 (See FIG. 9). Joint 110 is
connected to cylinder 106 by threads 155 and has a conduit 156
which, in the position shown, communicates with port 157 drilled in
cylinder 106. Halfdog set screws 159 aid in aligning joint 110 in
this position by running shoulder 160 of the joint back up against
the set screws. For running operations joint 110 is held in this
position by shear screw 158. Port 157 is connected by an external
conduit 157a to port 135 in tool 120 (See FIG. 10). Thus, fluid
pressure may be applied to the left side of piston 130 through the
running pipe string.
As stated before, when the flowline hub has been latched in place,
to remove tool 120, it is necessary to move piston 130 to the left
of the position shown in FIG. 10. To accomplish this, tool joint
110 is screwed further down into cylinder 106 by applying torque to
the running string to first shear screw 158 and then turning the
running string. Joint 110 will bottom up in cylinder 106 so that
conduit 156 now communicates with cylinder port 161 which is
connected by another external conduit 161a to port 136 (FIG. 10) on
the rod side of piston 130. Bleed port 162 and vent 163 prevent
pressure build up under the lower portion of joint 110. Fluid
pressure may now be applied from the surface through the running
string and joint 110 to release tool 120 from hub 32, as previously
explained with reference to FIG. 10. To pull hub 32, the external
conduits 157a, 161a would be interchanged so that port 157 is
connected to port 136 in tool 120, and port 161 is connected to
port 135. The same procedure described for running operations would
then be used for pulling operations.
The installation of all equipment shown in FIG. 1 except flowline
connector 33 has been described. With tree hub 31 and flowline hub
32 securely installed in cradle 30, it is now necessary to install
connector 33 between hubs 31 and 32 to provide flow communication
between flowlines 35 and flow loops 25. The installation and
construction of connector 33 will now be explained.
To completely understand the installation of connector 33 reference
is now made to FIG. 13. For running connector 33, the same guide
frame 100 shown in FIGS. 8 and 9 is used. However, tool 120, tool
joint 110 and running string 107 shown in FIG. 9 are removed.
Instead, a rotating union 300 is installed in the cylindrical
passageway through box 104. Running string 107 is now connected by
a conventional threaded connection to union 300. Connected to the
lower end of union 300 is connector running and pulling tool 320,
which is connected also to running neck 203. Running neck 203 is
fastened to running sleeve 202, a portion of connector 33. A full
description of running and pulling tool 320 and running neck 203
will follow.
With connector 33 attached through tool 320 to guide frame 100 and
running string 107 at the water surface, rotating union 300 is
shear pinned at 300a to prevent rotation of connector 33, and the
whole assembly is lowered toward the underwater wellhead and cradle
30, to position connector 33 for engagement with tree hub 31 and
flowline hub 32 (See FIG. 1). Guide cables 5, guide tubes 102, and
running string 107 provide initial guidance. As bell bottom 103
reaches tube 21 further alignment is attained which is also aided
by running sleeve 202 entering guide channels 65, attached to
cradle 30. Final alignment is accomplished by connector yoke pieces
61, retainer ring 229 and the beveled ends 240 of cylinder 200. In
this fully supported and aligned position connector 33 may be
engaged and disengaged with hubs 31 and 32 as described
hereafter.
Looking now at FIG. 14, an exploded view, the components of
connector 33 may be seen. The exploded pieces to the left of piece
210 are typical of the pieces which lie in an opposite manner to
the right of piece 210.
Connector 33 comprises a cylinder 200 surrounded by annular running
sleeve 201 which has a flange portion 202 for connecting to running
neck 203 with bolts 204. Running neck 203 and its function will be
subsequently described. Three vertical holes 205 are drilled
through flange 202 and cylinder 200 to receive fluid nipples 206.
O-rings 207 and 208 seal around flange 202 and nipples 206
respectively.
Nipple receptacle 210 has a circular flange portion 211 with
smaller diameter hub portions 212 projecting from each side. Three
holes 213 are drilled in rib 211 so that they will line up with
holes 205 in sleeve 201 when receptacle 210 is centered inside of
cylinder 200. Tapped radial holes 209 are provided in sleeve 201
and cylinder 200 to communicate with flat bottom radial holes 214
in rib portion 211. Half dog set screws 200 may then be inserted to
affix sleeve 201, cylinder 200 and receptacle 210 to one another. A
pair of flow bores 215 and a pair of hydraulic fluid bores 216 pass
longitudinally through receptacle 210. Pressure conduits 217 also
pass through receptacle 210. Each one of these conduits 217 is in
communication with one of the outside holes 213. Middle hole 213 is
in communication with pressure conduit 218 which passes through
flange portion 211.
Other components of connector 33 include tube retainer plate 222,
pressure ring 223, a set of latch keys 224, latch cylinder 225, a
pair of flow tubes 226, a pair of hydraulic tubes 227, and a pair
of pressure tubes 228. Also included is retainer ring 229, ram 230,
seal ring 231, various bolts, nuts, and O-rings for sealing.
To understand the function of the various components of connector
33 reference is now made to FIGS. 15A, 15B and 15C top sectional
views, which show connector 33 seated on connector yoke pieces 61.
Tree hub 31 and flowline hub 32 are latched in place within the
support cradle. Channel guide pieces 65, previously described, are
also shown.
Connector cylinder 200 lies between yokes 61 abutting the inner
face of each yoke. The ends of cylinder 200 are beveled at 240,
cooperating with yoke bevels 63 to aid in alignment of connector 33
as it is installed. Each end of cylinder 200 is threaded at 241 to
receive retainer ring 229. Retainer ring 229 provides the bearing
surface for supporting connector 33 on the curved surface 62 (FIG.
2) of yoke pieces 61. As previously explained running sleeve 201,
cylinder 200, and nipple receptacle 210 are fixedly attached to
each other by set screws 220. Running sleeve 201 cooperates with
guide channels 65 for initial alignment of connector 33 as it is
installed.
A latch cylinder 225 is slidingly disposed in cylinder 200 one on
each side of receptacle 210. The outside diameter of latch cylinder
225 is slightly less than the inside diameter of retainer ring 229,
allowing latch cylinder 225 to slide back and forth within cylinder
200. An annular shoulder 242 is provided to cooperate with retainer
ring 229 to retain latch cylinder 225 within cylinder 200. An inner
annular lip 243 engages latch keys 244, the function of which will
be more fully understood subsequently.
Cylindrical ram 230, pressure ring 233, flow tubes 226, tube
retainer plate 222 and hydraulic tubes 227 and pressure tubes 228
(FIG. 14) are slidingly disposed within latch cylinder 225 and
receptacle 210. Retainer plate 222 is attached by bolts to ram 230.
Annular grooves, such as 244, are machined on the exterior of flow
tubes 226, hydraulic tubes 227 and pressure tubes 228, retainer
plate 222 being split to facilitate mounting around these tubes at
annular grooves 244. Thus, the tubes 226, 227 and 228, ram 230,
pressure ring 233, and retainer plate 222 are all fixed for
movement together. Ram 230 has a flange lip 245 and a frustoconical
inner flange surface 246 in which the seal ring 231 is placed.
Latch key 224 comprises a shank portion 250, an inwardly projecting
lip portion 251, an inwardly projecting foot portion 252, a
outwardly projecting heel portion 253, and an outer groove 254.
Latch keys 224 are held in position by latch cylinder 225, ram 230,
pressure ring 233, and sliding latch ring 255. Ring 255 is spring
loaded by compression coil springs 255a, preventing latches 224
from prematurely moving around the outer end of ram 230. Springs
255a are mounted in sockets 2306 drilled in face 230a of ram 230,
and over pins 255b attached to ring 255.
For running and installing connector 33, its components are first
positioned as shown in FIG. 15A. In this position all tubes 226,
227 and 228 lie within the face to face dimension between the
flange of hubs 31 and 32, preventing interference when lowering
connector 33. Once the connector has been lowered into its resting
position on yokes 61 in the support cradle, pressure is applied
through center nipple 206 and conduit 218 (FIG. 14) of receptacle
210 into area 260. This pressure forces latch cylinder 225, ram
230, pressure ring 233, latches 224, and tubes 226, 227 and 228
outwardly first to the position shown in FIG. 15B. At this point
flange lip 245 of ram 230 and locking flange 98 of hub 32 are
abutting one another, seal ring 231 is compressed for sealing and
flow tubes 226 and hydraulic tubes 227 have sealingly engaged hub
32 (See FIG. 7 also).
Since ram 230 can move outwardly no further, only latch cylinder
225 and latches 224 will continue to react to pressure within area
260. They will continue to move outwardly, compressing springs
255a, until latch lip 251 falls behind locking flange 98, as shown
in FIG. 15C, where latch keys 224 will become stationary since
latch foot 252 and latch ring 255 are abutting the back of flange
lip 245. Continued pressure will move latch cylinder 225 further
outward, lip 243 disengaging groove 254 and engaging the inclined
surface 260 on the back of lip portion 251. This finally locked
position is shown in FIG. 15C. The angles of the inclined surfaces
of lip 243 are self-locking, so that pressure may be relieved from
area 260 without fear of disengaging latch keys 224.
As will be noticed from FIG. 14 pressure tubes 228 are shorter than
tubes 226 and 227. Due to their shorter lengths, pressure tubes 228
do not engage hubs 31 and 32. On full engagement of connector 33
tubes 228 terminate in the area around tubes 226 and 227 enclosed
by seal ring 231. As was previously described, one tube 228 at each
end of connector 33 communicates with an outer hole 213 in the rib
portion 211 of receptacle 210. The other set of pressure tubes 228
communicate with the other outer hole 213. Thus, pressure may be
applied through one set of pressure tubes to check for leaks around
ring seal 231 and O-ring seals 259 which surround flow tubes 226
and hydraulic tubes 227. The other set of pressure tubes 228 may be
used for return of test fluids or to allow circulation around ring
seal 231 to displace salt water which may be present.
To release connector 33 from engagement with hubs 31 and 32,
pressure is applied in area 265, through a port (not shown) in
cylinder 200. This forces latch cylinder 225, ram 230, latch keys
224, tubes 226, 227, and 228 etc. eventually back to the fully
disengaged position shown in FIG. 15A.
To fully understand the construction and function of tool 320 and
neck 203 (FIG. 13) reference also is now made to FIG. 16. This
drawing shows tool 320, running and pulling neck 203, flange 202 on
the running sleeve 201, connector cylinder 200, and connector
nipple receptacle 210.
Neck 203 has a flange portion 301 which is attached to flange 202
by bolts 302. A tubular prong portion 303 extends upwardly from
flange 301. The upper end of prong 303 is provided with
frustoconical surface 304. Four V-bottom grooves 305 are
circumferentially cut on the interior of prong portion 303. Drilled
longitudinally through the walls of neck 203 are four holes 306,
only two of which can be seen in the drawing, each one
communicating through ports 307 with a different groove 305. Three
of holes 306 connect with conduits 26 which sealingly engage holes
213 in receptacle 210 for supplying engaging pressure and test
fluid to connector 33 as previously described with reference to
FIGS. 13 and 14. The fourth hole 306 communicates with port 307
which may in turn be connected by a hydraulic line (not shown) to a
port (not shown) in cylinder 200 to supply pressure in area 265
(FIG. 15C) for disengagement of connector 33.
The interior of prong 303 slidingly receives a groove protection
cylinder 308 the lower interior of which accommodates a spring 309.
An upper annular shoulder 310 is provided with O-ring 311. The
length of groove protector 308 is such that when tool 320 is
removed, cylinder 308, being spring biased, will cause O-ring 311
to be placed above the uppermost V-groove 305 in prong 303. This
will seal the V-grooves 305 against sea water and debris which
might plug up the ports. A lower annular shoulder 312 and half dog
set screw 313 limit the upward movement of cylinder 308 and prevent
it from being lost. A vent hole 308a allows free movement of
cylinder 308 by preventing pressure build-up.
Tool 320 has a generally cylindrical body and is provided with
connection means such as internal threads 321 for connection to
union 300. (See FIG. 13). At its lower end, tool 320 has a smaller
diameter prong portion 322. A downwardly facing annular shoulder
323 joins prong 322 to the body of tool 320. External threads are
machined at 324 to receive cylindrical sleeve 325.
The lower end of sleeve 325 has a frustoconical surface 326. The
internal diameter of sleeve 325 is slightly larger than the
external diameter of neck prong 303. Looking also at FIG. 17 sleeve
325 has a J-slot 327 which opens at its lower end to receive a pin
328 which projects outwardly and is affixed to neck prong 303. To
engage tool 320 and running and pulling neck 203, J-slot 327 and
pin 328 must be aligned as the sleeve 325 of tool 320 is lowered
around prong 303. Frustoconical surfaces 304 and 326 aid in
concentric alignment. When the upper surface 329 of J-slot 327
contacts pin 328 tool 320 may be rotated until pin 328 engages the
closed end 330 of J-slot 327. Naturally there is a limited amount
of axial freedom at this point between running neck 303 and tool
320. When the tool 320 is pushed all the way down onto neck 303 it
is engaged as shown in FIG. 16. However, when it moves up such that
pin 328 is in the bottom of slot 330 the pairs of O-rings 331a on
prong 322 seal off grooves 305 so that the handling lines do not
fill up with sea water.
Tool prong 322 is provided with circumferential V-grooves 331 which
in the fully engaged position mate with the internal V-grooves 305
of neck prong 303. Each one of V-grooves 331 is connected by a port
332 to a separate vertical passage 333 drilled in prong 322. These
passages 333 in turn are connected by internal ports 334 to
external outlets 335 around the exterior of tool 320. These outlets
may in turn be fitted with hydraulic hoses (not shown) which are
run to the surface to a pressure source at the working boat or
platform.
From the description of tool 320, neck 203, and guide frame 100, it
can readily be understood that not only can connector 33 be lowered
into engagement with hubs 31 and 32, but it may also be disengaged
and returned to the surface.
In summary, with reference to FIG. 1, it has been shown how
underwater flowlines 35 may be remotely connected to flow loops 25
of an underwater production tree 10. The construction of a
preferred embodiment of flowline connection means comprising
support cradle 30, tree hub 31, flowline hub 32, and connector 33
has been explained. A method of installing the flow line connection
means has been described. A unique method of handling the
installation of flowlines 35 has also been disclosed. As can now be
understood from the disclosure, a remote flowline connector may be
installed or removed independently of production tree and flowline
installation.
Many other variations and uses of the described methods and
constructions may be made by one skilled in the art without
departing from the spirit of the invention. It is, therefore,
intended that the invention be limited only by the scope of the
claims which follow.
* * * * *