U.S. patent number 3,918,747 [Application Number 05/401,510] was granted by the patent office on 1975-11-11 for well suspension system.
This patent grant is currently assigned to Norman A. Nelson. Invention is credited to Samuel W. Putch.
United States Patent |
3,918,747 |
Putch |
November 11, 1975 |
Well suspension system
Abstract
A well tubular suspension system, particularly adaptable for
underwater support of casings and well completions. A casing hanger
assembly which eliminates threads from the top portion of the
hanger and which may be engaged by a well tool telescopically
engaging the exterior of the hanger and releasably connected
thereto. The well tool includes locking means which may be actuated
by longitudinal movement. The well tool may be disconnected from
the hanger by rotational movement. Wash ports are eliminated from
the wall of the hanger by providing the ports in the wall of the
well tool. The well tool may be mechanically or hydraulically
actuated. Sealing means between the well tool and the hanger may be
utilized including a metal seal and a testing line may be included
in the well tool behind the seals for testing and/or monitoring
seal integrity. The hanger body may include a male hub which makes
it possible to install a squeeze seal packoff between hangers
without adding additional members to the system. An improved hanger
assembly for connection to a second tubular member is provided in
which a locking ring is provided having shearable holding means
intermediate the ends of the locking ring for reducing the tendency
of the ring to cock when locked. The locking ring also includes
improved tapered surfaces for positively expanding, and locking the
ring between the tubular members.
Inventors: |
Putch; Samuel W. (Houston,
TX) |
Assignee: |
Nelson; Norman A. (Houston,
TX)
|
Family
ID: |
23588061 |
Appl.
No.: |
05/401,510 |
Filed: |
September 27, 1973 |
Current U.S.
Class: |
285/4; 166/208;
166/217; 285/18; 285/39; 285/315; 285/330; 285/920; 285/123.2 |
Current CPC
Class: |
E21B
33/043 (20130101); Y10S 285/92 (20130101); E21B
2200/01 (20200501) |
Current International
Class: |
E21B
33/043 (20060101); E21B 33/03 (20060101); E21B
33/00 (20060101); F16l 035/00 () |
Field of
Search: |
;285/321,3,4,307,39,141,140,330,142,143,18,24,27,133R,133A,93,DIG.21,315
;166/208,217,131,149,150,184,224,123 |
References Cited
[Referenced By]
U.S. Patent Documents
Primary Examiner: Arola; Dave W.
Attorney, Agent or Firm: Fulbright & Jaworski
Claims
What is claimed is:
1. A pipe hanger assembly for connecting a casing hanger to a pipe
comprising,
an elongated tubular hanger body with upper and lower ends, said
lower end adapted for releasable connection to a pipe, said upper
end having an annular engaging notch on the outside diameter,
a well tool adapted to be connected to the pipe and lowered for
connection and release from the exterior of the hanger body, said
tool having a lower end adapted to telescopically engage the
outside of the end of the hanger body,
a resiliently expandable and contracting locking ring carried by
and facing inwardly from the well tool and adapted to engage the
notch on the hanger body for connecting the tool to the body,
a tapering member carried by the tool for axial slidable movement
relative to said ring for locking said ring and for releasing said
ring from the notch upon axial movement of the member, said hanger
includes axial extending groove means on the exterior and rotative
means for axially moving the tapering member away from the locking
ring including,
a thread on said well tool,
a threaded nut coacting with the thread on said tool, said nut
including longitudinal extending spline means for engaging said
hanger groove means whereby rotation of the well tool will provide
axial movement of the well tool and tapering member for releasing
the ring from the notch.
2. The apparatus of claim 1 wherein the body includes an external
upwardly facing shoulder and the well tool includes a seal at the
lower end thereof for seating on said shoulder and sealing off
between the outside of the body and the inside of an outer pipe
surrounding said body.
3. The apparatus of claim 1 including,
said well tool including a double acting fluid piston and cylinder
assembly connected to the tapering member for axially moving the
member relative to the ring.
4. The apparatus of claim 3 including a fluid conduit in said tool
connected to the cylinder and a port connected to the cylinder and
extending externally of said tool for actuating the piston.
5. The apparatus of claim 1 including an improvement in an assembly
for connecting the tubular hanger body to a third pipe coaxially
surrounding the hanger in which the body includes an annular recess
in its peripheral surface adjacent the third pipe, a radially
extending stop shoulder on the body at each end of the recess, a
resiliently expandable and contractible locking ring positioned in
said recess and axially slidable between said stop shoulders,
locking means on the body for locking the ring in an expanded
position, and a locking notch on the third pipe for receiving the
expanded and locked ring, the improvement comprising,
said locking notch including a locking shoulder at its lower end,
said locking shoulder tapering upwardly toward the hanger body,
said annular recess including a tapered shoulder at its upper end
extending toward the third pipe and extending to the peripheral
surface of the body adjacent the third pipe,
the top of the locking ring consisting of a tapered surface for
coacting with the tapered shoulder at the upper end of the recess,
and
the locking ring including a tapered locking surface for coacting
with the tapered locking shoulder on the third pipe.
6. The apparatus of claim 1 including, seal means on the interior
of the well tool for sealingly engaging the exterior of the hanger
body.
7. The apparatus of claim 2 wherein the seal is connected to the
well tool by a rotatable connection.
8. A pipe hanger assembly for connecting a casing hanger to a pipe
comprising,
an elongated tubular hanger body with upper and lower ends, said
lower end adapted for releasable connection to a pipe, said upper
end having an annular engaging notch on the outside diameter,
a well tool adapted to be connected to the pipe and lowered for
connection and release from the exterior of the hanger body, said
tool having a lower end adapted to telescopically engage the
outside of the upper end of the hanger body,
an inwardly biased resiliently expandable and contracting locking
ring carried by and facing inwardly from the well tool and adapted
to engage the notch on the hanger body for connecting the tool to
the body,
a tapering member carried by the tool for axial slidable movement
relative to said ring for locking said ring and for releasing said
ring from the notch upon axial movement of the member,
the well tool including a receiving recess positioned above the
tapering member for normally receiving the locking ring whereby the
well tool may be moved longitudinally downwardly over the upper end
of the body until the ring is resiliently biased into and engages
the notch on the body after which an upper pull on the well tool
moves the tapering member against the back of the ring thereby
locking the tool to the body without requiring rotative movement,
and
said well tool including rotative means for axially moving the
tapering member above the locking ring for unlocking the ring from
the notch.
9. In an assembly for connecting first and second tubular members
to and from each other in a well by longitudinal movement of the
first member, said first member including an annular recess in its
peripheral surface adjacent the second member, a radially extending
stop shoulder on the first member at each end of the recess, a
resiliently expandable and contractible locking ring positioned in
said recess and axially slidable thereon between said stop
shoulders, locking means on the first member for locking said ring
in an expandable position, a locking notch on the second member in
its peripheral surface adjacent the first member for receiving the
expanded and locked ring, the improvement comprising,
shearable holding means intermediate the ends of the locking ring
which when sheared by downward longitudinal movement of the first
member allows the upper portion of the ring to releasably lock the
first and second members together, said locking ring includes upper
and lower sections and the shearable means includes a shear pin
interconnecting said sections.
10. In an assembly for connecting first and second tubular members
to and from each other in a well by longitudinal movement of the
first member, said first member including an annular recess in its
peripheral surface adjacent the second member, a radially extending
stop shoulder on the first member at each end of the recess, a
resiliently expandable and contractible locking ring positioned in
said recess and axially slidable thereon between said stop
shoulders, locking means on the first member for locking said ring
in an expandable position, a locking notch on the second member in
its peripheral surface adjacent the first member for receiving the
expanded and locked ring, the improvement comprising,
shearable holding means intermediate the ends of the locking ring
which when sheared by downward longitudinal movement of the first
member allows the upper portion of the ring to releasably lock the
first and second members together, said shearable means includes a
thin walled section in said locking ring.
11. In an assembly for connecting first and second tubular members
to and from each other in a well by longitudinal movement of the
first member, said first member including an annular recess in its
peripheral surface adjacent the second member, a radially extending
stop shoulder on the first member at each end of the recess, a
resiliently expandable and contractible locking ring positioned in
said recess and axially slidable thereon between said stop
shoulders and including an opening in the back of said ring,
locking means on the first member for locking said ring in an
expandable position, a locking notch on the second member in its
peripheral surface adjacent the first member for receiving the
expanded and locked ring, the improvement comprising,
shearable holding means intermediate the ends of the locking ring
which when sheared by downward longitudinal movement of the first
member allows the upper portion of the ring to releasably lock the
first and second members together, said shearable holding means
including,
a shoulder on the first member, and
shear means positioned on the end of the shoulder and extending
into said opening on the back of said locking ring.
12. In an assembly for connecting first and second tubular members
to and from each other in a well by longitudinal movement of the
first member, said first member including an annular recess in its
peripheral surface adjacent the second member, a radially extending
stop shoulder on the first member at each end of the recess, a
resiliently outwardly biased expandable and contractible locking
ring positioned in said recess and axially slidable thereon between
said stop shoulders, locking means on the first member for locking
said ring in an expandable position, a locking notch on the second
member in its peripheral surface adjacent the first member for
receiving the expanded and locked ring, the improvement
comprising,
said locking notch including a locking shoulder at its lower end,
said locking shoulder tapering upwardly toward the first
member,
said annular recess including a tapered shoulder at its upper end
extending upwardly and toward the second member and extending to
the peripheral surface of the first member adjacent the second
member,
the top of the locking ring including a tapered surface for
coacting with the tapered shoulder at the upper end of the recess,
and
the locking ring including a tapered locking surface extending
outwardly and downwardly for coacting with the tapered locking
shoulder on the second member when the first member moves
downwardly relative to the second member and the ring is positioned
adjacent the locking notch.
13. A pipe hanger assembly for connecting a casing hanger to a
coaxial pipe positioned about the casing hanger comprising,
an elongated tubular hanger body with upper and lower ends, said
body including means for connecting the hanger to the interior of
coaxial pipe, said lower end adapted for a releasable connection to
a pipe, said upper end having an annular engaging notch on the
outside diameter of the body,
a well tool adapted to be connected to a pipe and lowered for
connection and release from the exterior of the hanger body, said
tool having a lower end adapted to telescopically engage the
outside of the upper end of the hanger body,
a resiliently expandable and contracting locking ring carried by
and facing inwardly from the well tool and adapted to engage the
notch on the hanger body for connecting the tool to the body,
a tapering member carried by the tool for axial slidable movement
relative to said ring for locking said ring and for releasing said
ring from the notch upon axial movement of the member,
rotative means for axially moving the tapering member toward and
away from the locking ring including,
axial extending groove means on the exterior of the hanger
body,
a thread on the well tool,
a threaded nut coacting with the thread on the tool, said nut
including longitudinal extending spline means for engaging said
hanger groove means whereby rotation of the well tool will provide
axial movement of the tapering member relative to the ring,
a packoff seal rotatably carried by the well tool, said seal
adapted to seal between the exterior of the hanger body and the
interior of the coaxial pipe, and
said hanger body including an external upwardly facing shoulder on
which the seal may seat and set and released by the well tool.
14. The apparatus of claim 13 including,
a longitudinal engagable and releasable connection at the top of
the well tool.
15. The apparatus of claim 13 including,
a second well tool adapted to be connected to a pipe and lowered
for connection and release from the exterior of the hanger
body,
a second annular notch on the outside of the diameter of the hanger
body,
a second resiliently expandable and contracting locking ring
carried by the second tool for engaging the second notch,
a second tapering member carried by the second tool for axially
slidable movement relative toward the second ring for locking said
second ring and movement away from the second ring for releasing
said second ring from the notch,
means for longitudinally but nonrotatably moving said second
tapering member relative to the said ring for locking said second
ring into the second notch.
16. The apparatus of claim 13 wherein the means for longitudinally
but nonrotatatively moving the second member includes a double
acting fluid piston and cylinder assembly connected to the second
member for longitudinally moving the second member relative to the
second ring.
17. The apparatus of claim 13 wherein the means for longitudinally
but nonrotatively moving the second member wherein the well tool
includes a ring receiving recess positioned above the second
locking ring for normally holding said second ring and said second
tapering member tapers downwardly and towards said hanger body
whereby upward pull on the second well tool will move the second
ring into the second annular notch on the hanger body.
Description
BACKGROUND OF THE INVENTION
The present invention is directed to a well suspension system, and
primarily, an underwater mudline suspension system for supporting
casing near the ocean mudline with improved reliability. Various
improvements to the present suspension system are provided. One is
an improved locking mechanism between adjacent tubular members
which is weight sensitive so that the weight helps energize or
expand the locking mechanism so that it will positively expand and
seat, and reduce the chance of collapsing and dropping of pipe.
Other improvements are directed to improved sealing mechanisms,
improved casing hangers, and provide alternate ways of connecting
onto the casing hangers.
The present suspension system can be used to drill a well,
temporarily abandon the well, re-enter the well, extend the well to
the surface for completion, or complete the well underwater.
SUMMARY
The present invention is directed to a well suspension system
having various improvements providing greater reliability and
flexibility by providing improved underwater connectors, seals,
locking assemblies and casing hangers while simplifying the
equipment.
One feature of the present invention is the elimination of the
usual threads on the top portion of a casing hanger because such
threads must be engaged remotely, and, if damaged, cause problems
of connection. The present invention provides a re-connecting
mechanism in which the casing hanger has an upwardly directed male
member having non-threadable connecting means on its outside
diameter which may be connected to a telescoping female well tool.
The connection may be made by a longitudinal downward movement for
actuating a resiliently expandable and contracting locking ring
between the casing hanger and the well tool. Rotative means may be
provided for rotatively releasing the well tool from the casing
hanger.
Another feature of the present invention is the elimination of wash
ports through the wall of the casing hanger thereby eliminating
possible leaks, simplifying the equipment and adding flexibility
and versatility by providing wash ports in the wall of the well
tool which is removable. The effectiveness of the wash ports may be
increased by directing their discharge downwardly.
A still further feature of the present invention is the provision
of a well tool for connection to a well casing hanger which may be
either manually actuated to provide a longitudinal stab-on
connection and a rotatable releasing connection or by providing a
well tool which includes a double acting fluid piston and cylinder
assembly for providing a hydraulic connection to and release from
the casing hanger.
Yet a still further object of the present invention is the
provision of a resilient seal means connected to the well tool for
engaging the casing hanger body, and a metal seal connected to the
well tool for engaging the casing hanger body which may be readily
changed when damaged, but yet provide a rugged and superior seal. A
testing conduit may extend from the exterior of the well tool to a
point intermediate the resilient seal and the metal seal for
testing the seal.
A still further object of the present invention is the provision of
a well suspension system having improved annulus packoff by
providing a squeeze seal packoff about the upstanding male hub of
the casing hanger to provide a seal between the hanger and an outer
tubular member without requiring additional members to be connected
to the system. In addition, the seal packoff may be connected to
the well tool and positioned about the hanger at the same time the
well tool is connected to the hanger.
Still a further object of the present invention is the provision of
a packoff seal assembly between the exterior of the well hanger and
the concentric tubular member which includes latching means for
connecting the seal assembly to the outside of the hanger body and
rotative means for actuating and releasing the seal assembly.
Still a further object is the provision of an improved locking
assembly for connecting first and second tubular members together
which includes a resiliently expandable and contractible locking
ring axially movable on one of the members for engagement with the
second member in which shearable holding means is provided
intermediate the ends of the locking ring which is sheared by
downward longitudinal movement of the first member for allowing the
upper portion of the ring to releasably lock the first and second
members together. The intermediate holding means insures that the
locking ring does not cock but will uniformly be actuated and
locked.
Still a further object of the present invention is the improvement
of a locking assembly for connecting first and second tubular
members together including a resiliently expandable and contracting
locking ring having tapered surfaces at the top of the ring and
under the locking shoulder for coacting with the first and second
members for positively and securely providing a weight sensitive
locking mechanism which will, when expanded and seated, reduce the
chance of collapsing and dropping of the casing.
Still other and further objects, features and advantages will be
apparent from the following description of presently preferred
embodiments of the invention, given for the purpose of disclosure
and taken in conjunction with the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is an elevational view, partly in cross section, showing a
landing sub connected to a fluted casing hanger assembly which
supports an inner string of pipe inside of a drive pipe,
FIG. 2 is a cross-sectional view taken along the line 2--2 of FIG.
1,
FIG. 3 is a fragmentary elevational view, partly in cross section,
showing the wash ports on the landing sub of FIG. 1 in the open
position while attached to the casing hanger,
FIG. 4 is an elevational view, partly in cross section, showing an
expanding casing hanger being run through casing and into the
fluted casing hanger of FIG. 1,
FIG. 5 is an elevational view, partly in cross section,
illustrating the expanding casing hanger of FIG. 4 in position
inside the fluted casing hanger to prevent further downward
movement,
FIG. 6A is an enlarged view of a portion of the expanding casing
hanger shown in FIG. 5 illustrating the hanger locking mechanism
being run inside of a casing,
FIG. 6B is a view similar to that of FIG. 6A showing the hanger
locking mechanism in locked position in the fluted casing
hanger,
FIG. 7A is an enlarged view of a modified casing hanger locking
mechanism being run inside of a casing,
FIG. 7B is a view similar to that of FIG. 7A showing the locking
mechanism locked in the fluted hanger,
FIG. 8A is an enlarged view of a portion of an expanding casing
hanger showing another modified hanger locking mechanism being run
inside a casing,
FIG. 8B is a view similar to that of FIG. 8A showing the locking
mechanism positioned in the locked position in a second casing
hanger,
FIG. 9A is an enlarged view of a portion of an expanding casing
hanger showing a still further modified version of a hanger locking
mechanism being run inside a casing,
FIG. 9B is a view similar to that of FIG. 9A showing the modified
hanger locking mechanism of FIG. 9A locked in place in a second
casing hanger,
FIG. 10 is an elevational view, in cross section, of an expanding
casing hanger set inside a fluted casing hanger and a seal packoff
assembly installed between the two hangers,
FIG. 11 is an enlarged cross-sectional view of the seal packoff
assembly of FIG. 10,
FIG. 12 is an enlarged elevational cross-sectional view showing a
modified packoff assembly locked into place on the body of an
expanding casing hanger,
FIG. 13 is an elevational view, in cross section, of a casing
hanger having the packoff assembly of FIG. 12 connected thereon,
and a remote control hydraulic operated connecting well tool locked
onto the expanding casing hanger,
FIG. 14 is a view similar to FIG. 13 showing the remote control
hydraulic connector well tool unlocked from the expanding casing
hanger,
FIG. 15A and 15B are continuations of each other and are enlarged
fragmentary elevational views in cross section showing the remote
hydraulic connector well tool and pack off of FIGS. 13 and 14,
FIG. 16 is an elevational view, in cross section showing a remote
stab-on mechanical connector locked into the expanding casing
hanger,
FIG. 17 is a view similar to FIG. 16 showing the remote stab-on
mechanical connector unlocked from the expanding casing hanger,
and
FIG. 18 is an enlarged elevational view, in cross section, showing
the remote stab-on mechanical connector locked onto the top of the
expanding casing hanger.
DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring now to the drawings, and particularly to FIG. 1, in the
drilling of an oil and/or gas well, a drive pipe 10 is drilled,
jetted or otherwise driven into place, and a butt weld sub 12 is
installed at the desired location in the drive pipe 10. In
underwater applications, the drive pipe 10 would extend upwardly to
the drilling rig.
A drill bit is run inside the drive pipe 10 and drilled to the
required depth for the first casing string. After the hole is
drilled, the bit is removed and a casing 14 is run inside the drive
pipe 10 and suspended from a fluted casing hanger assembly 16 by a
landing sub assembly 18. A shoulder 20 on the outside diameter of
the fluted casing hanger assembly 16 engages the seat 22 in the
butt weld sub and supports or hangs the casing 14. Cement is pumped
through the inside and out of the bottom of the casing 14 and comes
up the annulus 24 between the casing 14 and the drive pipe 10.
Returning cement passes up through the flutes 26 and back up to the
drilling rig. The above-named description of initially suspending a
casing hanger is generally conventional.
However, casing hangers frequently have an upstanding threaded
female member which must be engaged remotely in various operations.
However, if the threads on the hanger become damaged, connecting
equipment to the hanger causes problems. One of the features of the
present invention is the provision of a well tool such as the
landing sub 18, which includes a downwardly directed female member
for engaging a non-threaded upper male end 28 of a casing hanger
16, and connects to the outside diameter of the end 28. The
non-threaded connection may include an annular engaging notch 30 on
the outside diameter of the upper end 28 of the casing hanger 16.
The landing sub 18 includes an actuating nut 32 threadably secured
to the body of the landing sub 18. A recess 34 is provided in the
landing sub for initially holding a resiliently expandable and
retracting locking ring 36 prior to connecting the landing sub 18
to the upper end 28 of the hanger assembly 16. A tapered surface 38
is provided which is axially movable relative to the ring 36 for
forcing the ring 36 inwardly and into the notch 30. The axial
movement may be provided by rotation of the landing sub 18 relative
to the actuating nut 32. In order to provide for the rotation
between the actuating nut 32 and the skirt 19, the lower end of the
actuating nut 32 engages stop lugs 40 on the outside diameter of
the upper end 28 of the hanger 16. Therefore, connection and
disconnection of the landing sub 18 and the hanger assembly 16 may
be provided by rotative movement therebetween.
In addition, in the past, it has been a general practice to provide
wash ports in the casing hanger assembly to wash out cement from
the annulus above the hanger assembly 16 and the pipe 10. However,
such wash ports create possible leaks. The present invention
provides the wash ports 42 in the well tool 18 between seals 44.
Therefore, in order to insure that the landing sub 18 is not
cemented into the drive pipe 10, the landing sub 18 is rotated, as
best seen in FIG. 3, a sufficient number of turns, exposing the
wash ports 42 through the interior of the landing sub 18. Fluid can
now be pumped down the inside of the landing tool 18 out the wash
ports 42 and back up the annulus 24 between the landing sub 18 and
the drive pipe 10 washing out the cement. It is noted in FIG. 3
that the landing sub 18 is only backed off sufficiently for the
wash ports 42 to clear the upper end 28 of the casing hanger
assembly 16 but not sufficiently so that the taper 38 is removed
from the back of locking ring 36 which would inadvertently release
the connection between the landing sub 18 and the hanger assembly
16. It is also noted that it is preferable to have the wash ports
42 directed downwardly when washing out to increase the washing
action in the annulus 24. After washing out, the landing sub 18 is
rotated back to its initial position as best seen in FIG. 1.
After washing out and the cement has set, a bit is run inside the
casing 14 and a hole drilled to the depth required for the next
smaller size casing string. After the hole is drilled, the bit is
removed, and as best seen in FIGS. 4 and 5, casing 46 is run inside
of the casing 14 and supported from an expanding casing hanger
assembly 50 and a landing sub 51. The expanding casing hanger
assembly 50 includes a resiliently expandable and contracting
locking ring 52 and is shown in a contracted position in FIG. 4 as
the casing hanger 50 is being run through casing 14 and the fluted
casing hanger assembly 16. A locking notch 54 is provided in the
fluted casing hanger assembly for engagement by the locking ring
52, as best seen in FIG. 5, for supporting the expanding casing
hanger assembly 50 from the fluted casing hanger assembly 16. In
addition, the expanded casing hanger assembly 50 may include on its
interior a locking notch 56 for landing a still smaller string of
casing in another expanding casing hanger assembly therein.
One of the features of the present invention is the provision of
various improvements in a resilient locking ring. Referring now to
FIGS. 6A and 6B, an enlarged view of the resilient locking ring 52
of FIGS. 4 and 5 is best seen. The casing hanger assembly 50
includes an annular recess 60 for carrying the resilient locking
ring 52. An upward radially extending stop shoulder 62 is provided
at the top of the recess 60 and a lower radially extending stop
shoulder 64 is provided at the bottom end of the recess 60. The
recess 60 carries the locking ring 52 and allows it to contract
inwardly into the recess 60 as the hanger assembly 50 is moved
downhole through a casing 14, as best seen in FIG. 6A. The ring 52
includes an upper locking portion 66 and a lower key portion 68 for
coacting with the locking notch 54 in the casing assembly 16, as
best seen in FIG. 6B. The locking notch 54 includes an upper
locking portion 71 and a lower key receiving portion 73. The key 68
prevents the locking portion 66 of the ring 52 from expanding
outwardly and engaging shoulders in the well string until the key
68 is located adjacent the key receiving portion 73. The locking
notch 71 includes a locking shoulder 76 at its lower end which
tapers upwardly toward the casing hanger 50. The recess 60 includes
a locking surface 78 having a tapered shoulder at its upper end
extending toward the casing assembly 16 and directed upwardly and
extending to the outer peripheral surface of the casing assembly
50. The locking portion 66 of the locking ring 52 includes coacting
tapered surfaces 70 and 72 which coact with the tapered shoulders
78 and 76, respectively, whereby when the locking portion 66
becomes positioned adjacent the portion 71 of the locking notch 54
in the casing assembly 16, the ring 52 will be urged outwardly, the
tapered shoulder 78 will engage the tapered surface 78 on the upper
portion 66 of the locking ring urging the upper portion 66
outwardly and holding it in an outward position so long as weight
is exerted downwardly on the casing assembly 50. In addition, the
tapered locking surface 72 will coact with the tapered locking
shoulder 76 on the casing assembly 16 to securely hold the casing
assembly 50 suspended and seated in the casing assembly 16 so that
so long as the weight of the casing hanger assembly 50 and its
connected string is maintained on the locking ring 52, the locking
ring will be expanded and seated and reduce the chance of
collapsing and dropping the string.
Other and further modifications of a locking ring mechanism may be
provided as best seen in FIGS. 7A, 7B, 8A, 8B, 9A and 9B where like
character references refer to like parts with the addition of the
suffix "a", "b", and "c". Referring now to FIGS. 7A and 7B, a
resiliently expandable and contractible locking ring 52a is carried
in a recess 60a in the casing hanger 50 and is retractable therein
when moving through a casing 14 and is expandable for engaging a
locking notch 54a in the casing hanger assembly 16. The ring 52a
includes a transversely extending opening 80 which initially fits
over a holding shoulder 82 on the casing assembly 50 for allowing
limited radial and axial movement of the expandable and retracting
ring 52a on the shoulder 82 as the assembly 50 is moved downhole. A
ring 84 is connected to the shoulder 82 by a shear pin 86 for
initially restricting the longitudinal or axial movement of the
locking ring 52a relative to the recess 60a. When the locking ring
52a is brought into alignment with the locking notch 54a on the
casing hanger assembly 16 a locking shoulder 72a on the ring 52a
engages locking shoulder 76a on the casing assembly 16. Further
downward force shears pin 86. Tapered surface 88 on hanger assembly
50, upon further downward movement, contacts and engages taper 90
on the back of locking ring 52a forcing upper portion 66a of the
locking ring 52a into the locking notch 54a. Further downward
movement of the casing hanger assembly 50 brings locking shoulder
92 against the back 94 of the locking ring holding the upper
portion 66a in the expanded and locked position. While releasable
locking rings, such as shown in U.S. Pat. No. 3,420,308, have been
used in the past, the present ring 84 and shear pin 86 are provided
intermediate the ends of the locking ring 52a which has the
advantage that the locking ring 52a is not subject to cocking and
misalignment in the latching mechanism.
Referring now to FIGS. 8A and 8B, a modified locking ring 52b is
provided having a transverse opening 80b coacting with a shoulder
82b on the casing hanger assembly 50 for allowing transverse
movement of the locking ring 52b into and out of the recess 60b. In
this embodiment the shear means consists of a shear pin 100
initially securing upper portion 66b and key portion 68b together.
When the locking shoulder 72b on the ring 52a encounters and
engages the locking shoulder 76b on the casing hanger assembly 16,
further downward movement of the casing hanger assembly 50 will
shear the shear pin 100 allowing the locking shoulder 92b to move
downward behind the back 94b of the locking ring 52b holding the
casing assembly 50 locked to and supported from the casing assembly
16.
Still a further modification of the locking ring is best shown in
FIGS. 9A and 9B in which the locking ring 52c is retractable and
expandable in a recess 60c in the casing hanger assembly 50 for
engagement in a locking notch 54c in the casing hanger 16. The
locking ring 52c may include a transverse opening 80c for
transversely moving relative to a shoulder 82c on the casing hanger
assembly 50 into and out of the recess 60c. In this embodiment, the
shear means intermediate the ends of the ends of the locking ring
52c includes a thin walled section 102 which parts in tension when
the locking shoulder 72c engages the locking shoulder 76c on the
outer casing hanger assembly 16 allowing the locking shoulder 92c
to move behind the back 94c of the locking ring 52c for hanging the
casing hanger assembly 50 from the casing hanger assembly 16.
Referring now to FIG. 5, the landing sub 51 may be removed by
rotation from the expanding casing hanger assembly 50. The landing
sub is connected to the expanding casing hanger assembly 50 with a
connection similar to that between the landing sub 18 and the
fluted casing hanger assembly 16, as more fully described in
connection with FIG. 1. Referring now to FIG. 10, after the landing
sub assembly 51 has been removed, a packoff assembly generally
indicated by the reference number 110 may be installed on the
expanding casing hanger assembly 50 by rotation by a suitable
connecting tool (not shown). Generally, the connecting assembly for
connecting the downwardly extending female member of the packoff
assembly 110 to the upstanding male upper end 28 of the casing
hanger assembly is similar to that of FIG. 1. Another feature of
the present invention is the availability of using a squeeze seal
packoff between the male upper end 28 of the casing hanger assembly
50 and the fluted casing hanger assembly 16. This is accomplished
by providing, as best seen in FIGS. 10 and 11, an upwardly directed
shoulder 114 on the casing hanger 50 and a squeeze seal packoff
generally indicated by the reference numeral 116 which is connected
to the packoff assembly 110. The packoff assembly 116 includes a
body 118 which is secured to the packoff assembly 110 by a ring 120
and has attached thereto a supporting ring 122 connected by bolts
124 and includes the seal member 126. As previously noted, the
packoff assembly 110 is longitudinally inserted over the upper end
28 of the hanger assembly 50 and right-hand rotation of the packoff
assembly 110 causes the latching ring 36b to be forced into the
engaging notch 30b as the taper 38b is rotated behind the ring 36b.
With the ring 36b locked in the engaging notch 30b further rotative
movement of the packoff assembly 110 will cause the skirt 19b to
rotate downwardly against the packoff assembly 110 squeezing the
packoff seal 126 between the hanger assembly 50 and the hanger
assembly 16 to provide an annulus seal.
If desired, a squeeze packoff seal may be inserted in the casing
hanger 50 and the casing hanger 16 independently of a connecting
type packoff assembly 110, as best seen in FIG. 12. The modified
compact packoff assembly 110a includes a body 121 having a skirt
connection 119 for connection to a suitable tool (not shown) for
attachment thereto to provide a rotative movement of the body 121
for actuating and/or release of the seal assembly 116a. The hanger
assembly 50 includes a locking notch 128 for securing the packoff
assembly 110a thereto. The packoff assembly 110a includes an
actuating nut 130 threadably connected to the body 121, and a seal
126a. The body 121 includes a tapered surface 133 for forcing a
locking ring 132 outwardly into the locking notch 128 and a recess
134 for initially receiving the locking ring 132 in an expanded
position. Downward movement of the packer assembly 110a will bring
the actuating nut 130 into engagement with coacting lugs on the
casing assembly 50 and position the locking ring 132 adjacent the
locking notch 128. Rotative movement of the body 121 will move the
tapered surface 133 behind the locking ring 132 for securing it in
the notch 128 thereby securing the packer assembly 116a to the
casing assembly 50. Also rotative movement of the body 121 will
then compress the seal 126a between the casing hanger assembly 50
and the casing hanger assembly 16 to provide the desired annulus
seal.
The use of the compact packoff assembly 110a allows increased
flexibility and versatility by allowing various types of
connections to be made to the upper end 28 of the casing hanger
assembly 50. As best seen in FIGS. 13, 14 and 15A, a remote control
hydraulic connector generally indicated by the reference numeral
136 may be provided. The connector 136 includes a body 138 carrying
a locking ring 140 for connection to the locking notch 30 of the
upper end 28 of the casing hanger assembly 50, a hydraulic piston
and cylinder assembly having a cylinder 142 with a piston 144
movable therein having an actuator sleeve 146 for moving relative
to the resilient locking ring 140 for moving ring 140 into and out
of the engaging latch 30. Fluid ports are provided at either end of
the hydraulic cylinder 142 such as port 148 which may lead to the
well surface for supplying fluid therefrom for moving the actuator
sleeve 146 into a locking position and a second port 150 which may
also lead to the well surface for supplying fluid therefrom for
supplying fluid to actuate the actuator sleeve 146 to a retracted
position. The hydraulic connector 136 may be suitably sealed to the
upper end 28 of the casing hanger assembly 50 by providing a
flexible seal 152 and a metal seal 154. A fluid conduit 156 may be
provided leading to a position between the seals 152 and 154 for
leading to the well surface for testing and/or monitoring the
seals. The seals 152 and 154 may be readily changed when damaged
since they are attached to the removable hydraulic connector 136.
FIG. 13 shows the hydraulic connector connected to the upper end 28
of the casing hanger assembly 50 by applying fluid through the port
148. FIG. 14 shows the hydraulic connector 136 being disconnected
from the casing hanger assembly 50 by applying fluid through the
port 150 and retracting the actuator sleeve 146.
The flexibility and versatility of the present system is also shown
in which another type of connector is provided for connecting to
the upper end 28 of the well casing hanger assembly 50, such as a
manual stab-on connector generally indicated by the reference
numeral 160 and shown in FIGS. 16, 17 and 18. The connector
operates by a straight longitudinal downward movement to connect
onto the casing hanger 50 and can be disconnected by rotation. The
stab-on connector 160 includes a body 162, a threaded actuator 164
which may, if desired, be shear pinned by pin 166 to the body 162
and may include an actuating pin 167 which will prevent rotation
when engaged in a spline connection such as 168 in the top of
packoff assembly 110a. A locking ring 172 is provided which is
initially positioned within a recess 174 and a tapered member 176.
The resilient locking ring 172 is initially carried in the recess
174 until the body 162 telescopes over the upstanding male upper
end 28 of the hanger assembly 50 and the ring 172 becomes
positioned adjacent and engages the locking notch 30 in the casing
hanger 50. Upward movement of the body 162 moves the sleeve surface
178 behind the locking ring 172 securely engaging the stab-on
connector 160 to the casing hanger assembly 50. To release, the
weight is slacked off of the body 162 so that the pin 167 engages
spline connection 168 in the packer assembly 110a. Rotation of the
body 162 to the right will break shear pin 166 allowing the body
162 to move upwardly moving the sleeve surface 178 upwardly from
behind the resilient locking ring 172 and into a second recess 170.
The connector 160 is then in the position shown in FIG. 17 and can
be longitudinally moved off of the well hanger assembly 50.
The present invention, therefore, is well adapted to carry out the
objects and attain the ends and advantages mentioned as well as
others inherent therein. While presently preferred embodiments of
the invention are given for the purpose of disclosure, numerous
changes in the details of construction and arrangement of parts may
be made which will readily suggest themselves to those skilled in
the art and which are encompassed within the spirit of the
invention and the scope of the appended claims.
* * * * *