U.S. patent number 3,924,678 [Application Number 05/488,430] was granted by the patent office on 1975-12-09 for casing hanger and packing running apparatus.
This patent grant is currently assigned to Vetco Offshore Industries, Inc.. Invention is credited to Arthur G. Ahlstone.
United States Patent |
3,924,678 |
Ahlstone |
December 9, 1975 |
**Please see images for:
( Certificate of Correction ) ** |
Casing hanger and packing running apparatus
Abstract
Casing hanger and packing running apparatus is lowered on a
tubular running string to locate the casing hanger and packing in a
surrounding housing beneath a body of water. The apparatus is
responsive to fluid pressure to expand the packing in the annular
space between the hanger body and the housing, and to actuate a
wedge-type lock which retains the packing in the packed off
condition. The apparatus is releasable from the casing hanger and
the packing for retrieval.
Inventors: |
Ahlstone; Arthur G. (Ventura,
CA) |
Assignee: |
Vetco Offshore Industries, Inc.
(Ventura, CA)
|
Family
ID: |
23939679 |
Appl.
No.: |
05/488,430 |
Filed: |
July 15, 1974 |
Current U.S.
Class: |
166/120; 166/208;
285/84; 166/124; 285/18 |
Current CPC
Class: |
E21B
33/043 (20130101) |
Current International
Class: |
E21B
33/043 (20060101); E21B 33/03 (20060101); E21B
023/06 (); E21B 033/035 () |
Field of
Search: |
;166/120,124,182,208,212,87 ;285/18,84 |
References Cited
[Referenced By]
U.S. Patent Documents
Primary Examiner: Brown; David H.
Attorney, Agent or Firm: Kriegel; Bernard
Claims
I claim:
1. Apparatus for effecting a seal between a wellhead and a hanger
disposed in the wellhead for supporting a tubular pipe string
extending into the well bore comprising; a running tool having a
body structure connectable to a running pipe string; means for
releasably connecting said body structure to said hanger; packing
means; means releasably connecting said packing means to said body
structure to enable said packing means to be set in sealing
relation to said hanger; locking means for locking said packing
means in sealing relation to said hanger including a locking member
actuatable longitudinally to lock said locking means; said body
structure having means responsive to fluid pressure supplied
through said running pipe string to set said packing means in
sealing relation to said hanger; and said body structure having
means responsive to fluid pressure outside of said running pipe
string for actuating said locking member longitudinally.
2. Apparatus as defined in claim 1, wherein said means for
releasably connecting said body structure to said hanger includes a
threaded connection.
3. Apparatus as defined in claim 1, wherein said means for
releasably connecting said body structure to said hanger includes
latch means carried by said body structure including latch elements
engageable with said hanger, and means for releasing said latch
elements.
4. Apparatus as defined in claim 1, wherein said means for
relaeasably connecting said body structure to said hanger includes
latch means carried by said body structure including latch elements
engage latch elements engageable with said hanger, and means for
releasing said latch elements in response to fluid pressure
supplied through said running pipe string.
5. Apparatus as defined in claim 1, wherein said locking means
comprises a resiliently deformable locking ring engageable with a
downwardly facing surface of said hanger upon deformation of said
locking ring to lock said packing means to place.
6. Apparatus as defined in claim 1, wherein said locking means
comprises a resiliently deformable locking ring engageable with a
downwardly facing surface of said hanger upon deformation of said
locking ring to lock said packing means in place, said locking
member and said locking ring having means for deforming said
locking ring upon longitudinal movement of said locking member.
7. Apparatus as defined in claim 1, wherein said locking means
comprises a resiliently deformable locking ring engageable with a
downwardly facing surface of said hanger upon deformation of said
locking ring to lock said packing means in place, said locking
member being in the form of a wedge shaped ring for deforming said
locking ring upon longitudinal movement of said locking member.
8. Apparatus as defined in claim 1, wherein said locking means
comprises a resiliently deformable locking ring engageable with a
downwardly facing surface of said hanger upon deformation of said
locking ring to lock said packing means in place, said locking
member being in the form of a wedge shaped ring for deforming said
locking ring upon longitudinal movement of said locking member,
said locking ring and said locking member having coengageable
locking wedge surfaces.
9. Apparatus as defined in claim 1, said packing means comprising a
support sleeve, a resilient elastomeric packing element supported
on said support sleeve, means releasably connecting said locking
member to said support sleeve, and said locking means including a
resiliently deformable lock ring carried by said support sleeve and
engageable by said locking member to be deformed thereby.
10. Apparatus as defined in claim 1, said packing means comprising
a support sleeve, a resilient elastomeric packing element supported
on said support sleeve, means releasably connecting said locking
member to said support sleeve, and said locking means including a
resiliently deformable lock ring carried by said support sleeve and
engageable by said locking member to be deformed thereby, said
locking member and said lock ring having companion wedge surfaces
formed on locking wedge angles for deforming said lock ring upon
longitudinal movement of said locking member.
11. Apparatus as defined in claim 1, wherein said means responsive
to fluid pressure supplied through said running pipe string to set
said packing means in sealing relation to said hanger includes
piston means longitudinally shiftable in said body structure.
12. Apparatus as defined in claim 1, wherein said means responsive
to fluid pressure supplied through said running pipe string to set
said packing means in sealing relation to said hanger includes
piston means longitudinally shiftable in said body structure, and
means initially holding said piston means against movement relative
to said body structure.
13. Apparatus as defined in claim 1, wherein said means responsive
to fluid pressure supplied through said running pipe string to set
said packing means in sealing relation to said hanger includes a
cylinder sleeve carried by said body structure, said cylinder
sleeve and said body structure having means defining a piston
chamber, a piston on said cylinder sleeve exposed to the pressure
of fluid in said piston chamber, and passage means for establishing
communication between said piston chamber and said running pipe
string.
14. Apparatus as defined in claim 1, wherein said means responsive
to fluid pressure supplied through said running pipe string to set
said packing means in sealing relation to said hanger includes a
cylinder sleeve carried by said body structure, said cylinder
sleeve and said body structure having means defining a piston
chamber, a piston on said cylinder sleeve exposed to the pressure
of fluid in said piston chamber, and passage means for establishing
communication between said piston chamber and said running pipe
string, said means responsive to fluid pressure outside said
running pipe string for actuating said locking member
longitudinally including an actuator piston engageable with said
locking member.
15. Apparatus as defined in claim 1, wherein said means responsive
to fluid pressure supplied through said running pipe string to set
said packing means in sealing relation to said hanger includes a
cylinder sleeve carried by said body structure, said cylinder
sleeve and said body structure having means defining a piston
chamber, a piston on said cylinder sleeve exposed to the pressure
of fluid in said piston chamber, and passage means for establishing
communication between said piston chamber and said running pipe
string said means responsive to fluid pressure outside said running
pipe string for actuating said locking member longitudinally
including an actuator piston engageable with said locking member,
said cylinder sleeve having means supporting said actuator piston
for longitudinal movement relative to said cylinder sleeve.
16. Apparatus as defined in claim 1, wherein said means responsive
to fluid pressure supplied through said running pipe string to set
said packing means in sealing relation to said hanger includes a
cylinder sleeve carried by said body structure, said cylinder
sleeve and said body structure having means defining a piston
chamber, a piston on said cylinder sleeve exposed to the pressure
of fluid in said piston chamber, and passage means for establishing
communication between said piston chamber and said running pipe
string, said means responsive to fluid pressure outside said
running pipe string for actuating said locking member
longitudinally including an actuator piston engageable with said
locking member, said cylinder sleeve having means supporting said
actuator piston for longitudinal movement relative to said cylinder
sleeve, and means for normally holding said actuator piston against
such longitudinal movement.
17. Apparatus as defined in claim 1, wherein said means responsive
to fluid pressure supplied through said running pipe string to set
said packing means in sealing relation to said hanger includes a
cylinder sleeve carried by said body structure, said cylinder
sleeve and said body structure having means defining a piston
chamber, a piston on said cylinder sleeve exposed to the pressure
of fluid in said piston chamber, and passage means for establishing
communication between said piston chamber and said running pipe
string, said means responsive to fluid pressure outside said
running pipe string for actuating said locking member
longitudinally including an actuator piston engageable with said
locking member, said cylinder sleeve having means supporting said
actuator piston for longitudinal movement relative to said cylinder
sleeve, said cylinder sleeve and said actuator piston having means
defining a chamber containing a compressible fluid for normally
holding said actuator piston against such longitudinal
movement.
18. Apparatus as defined in claim 1, wherein said means responsive
to fluid pressure outside said running pipe string for actuating
said locking member longitudinally including an actuator piston
engageable with said locking member.
19. Apparatus as defined in claim 1, wherein said means responsive
to fluid pressure supplied through said running pipe string to set
said packing in sealing relation to said hanger including piston
means carried by said body structure, said body structure having
passage means for controlling the application of fluid pressure to
said piston means.
20. Apparatus as defined in claim 1, said means responsive to fluid
pressure in said running pipe string to set said packing in sealing
relation to said hanger including a cylinder sleeve shiftably
carried by said body structure, said packing means including a
support sleeve, said means releasably connecting said packing means
to said body structure connecting said support sleeve to said
cylinder sleeve.
21. Apparatus as defined in claim 1, said means responsive to fluid
pressure in said running pipe string to set said packing in sealing
relation to said hanger including a cylinder sleeve shiftably
carried by said body structure, said packing means including a
support sleeve, said means releasably connecting said packing means
to said body structure connecting said support sleeve to said
cylinder sleeve annd including shear pins shearable upon removal of
said body structure from said hanger.
22. Apparatus as defined in claim 1, wherein said body structure
comprises an inner body having seal means engageable in said casing
hanger.
23. Apparatus as defined in claim 1, wherein said means responsive
to fluid pressure supplied through said running pipe string to set
said packing means in sealing relation to said hanger includes
means responsive to pressure fluid supplied through said running
pipe string to pull said packing means from sealing relation to
said hanger.
24. A running and operating tool for setting a packing and locking
assembly between a wellhead housing and a hanger for a tubular well
conduit comprising: a body having means at its upper end
connectable to a running pipe string; means at the lower end of
said body; means adapted to releasably connect said last-mentioned
means to the hanger; a cylinder sleeve reciprocable relative to
said body; said cylinder sleeve and said body having means defining
a piston chamber; a piston on said cylinder sleeve and in said
piston chamber; passage means for admitting fluid under pressure to
said piston chamber; said cylinder sleeve having means enabling
releasable connection with said packing means; and actuator means
responsive to fluid pressure outside of said tool including an
actuator member shiftable longitudinally of said cylinder
sleeve.
25. A running and operating tool as defined in claim 24, including
means for initially holding said actuator member against movement
relative to said cylinder sleeve.
26. A running and operating tool as defined in claim 24, including
means for initially holding said actuator member against movement
relative to said cylinder sleeve including means on said actuator
member and said cylinder sleeve providing a pressure chamber, said
actuator member having an area in said pressure chamber exposed to
the pressure therein.
27. A running and operating tool as defined in claim 24, including
means for initially holding said actuator member against movement
relative to said cylinder sleeve including means on said actuator
member and said cylinder sleeve providing a pressure chamber, said
actuator member having an area in said pressure chamber exposed to
the pressure therein, said cylinder sleeve having inlet means for
supplying pressure to said pressure chamber.
28. A running and operating tool as defined in claim 24, wherein
said body has inlet passages at both sides of said piston.
29. A running and operating tool as defined in claim 24, including
shearable means releasably connecting said cylinder sleeve to said
body.
30. A running and operating tool as defined in claim 29, wherein
said means defining said piston chamber comprises a cylinder head
threaded on said body, said cylinder sleeve and said body and
cylinder being sealingly and slidably engaged at opposite sides of
said piston, said actuator member including a differential area
piston sleeve disposed about said cylinder sleeve, and an outer
sleeve disposed about said cylinder sleeve and threaded thereon.
Description
The present invention relates to well apparatus, and more
particularly to apparatus for running a casing hanger into a
wellhead housing and effecting a seal in the region between the
hanger body and the surrounding wellhead housing disposed at the
upper end of the well bore.
In the drilling and completion of subaqueous or subsea well bores
extending downwardly from the floor of a body of water, apparatus
has been provided for lowering a casing string through a wellhead
housing at the top of the well and into the well bore, and for
landing a hanger body secured to the upper end of the casing string
in the wellhead housing. A sealing region or space is present
between the hanger body and housing. The casing string is cemented
in place and a suitable seal structure is then disposed in the
sealing region to provide an effective seal between the hanger body
and the surrounding wellhead. An apparatus employed in the
performance of the above operations is illustrated and described in
U.S. Pat. No. 3,492,026.
In the present invention, the casing hanger and the packing
assembly are lowered from a drilling barge or platform into
position within the wellhead through use of a running string
secured to a running and setting tool apparatus releasably
connected to the casing hanger and to the packing assembly. Fluid
pressure is operable on the setting and running tool to effect
deformation of the packing to form a seal between the housing and
the casing hanger and the locking of a wedge-lock device which
prevents the packing from recovering and breaking the seal.
Thereafter, the running and setting tool is released from the
casing hanger and from the packing and wedge-lock for recovery or
retrieval to the drilling rig.
In accordance with the present invention the setting and running
tool enables the use of fluid pressure applied through the usual
kill line or choke of the subsurface blowout preventer to test the
efficacy of the packing. Fluid pressure applied through the running
string acts on the setting and running tool to set the packing, and
the test pressure releases the locking wedge ring from its support
and actuates the wedge-lock mechanism.
More particularly, the wedge-lock device for holding the packing
packed off comprises a normally expanded resiliently contractable
locking ring engageable with a tapered shoulder externally of the
casing hanger body and a wedge ring normally held in a position
allowing the lock ring to be in its expanded position, but
releasable to be moved axially to circumferentially deform the lock
ring inwardly into locking co-engagement with a locking recess or
tapered shoulder of the casing hanger. The wedge ring and the lock
ring have cooperative locking wedge surfaces whereby the locking
action is maintained to hold the packing in a packed off
condition.
In the event it becomes necessary to release the packing the
locking wedge ring can be pulled from its locking position, for
example, by the pulling tool which is the subject of my copending
application for Pat. Ser. No. 475,586, filed June 3, 1974, for
"RETRIEVING TOOL FOR WELLHEAD PACKING."
Among the objectives of the invention is the provision of a tool or
apparatus for running a casing hanger and a packing and a locking
wedge device for holding the packing in a packed off condition in
the annular space between a casing hanger and the surrounding
wellhead or housing. Another objective of the invention is to
provide a running and setting tool operable in response to the
pressure of fluid supplied through the running string to initially
deform the packing and packoff the annular space and thereafter in
response to applied test pressure to actuate the wedge lock to the
locked position prior to removal of the setting and running tool
from the casing hanger.
This invention possesses many other advantages, and has other
purposes which may be made more clearly apparent from a
consideration of the forms in which it may be embodied. These forms
are shown in the drawings accompanying and forming part of the
present specification. They will now be described in detail, for
the purpose of illustrating the general principals of the
invention; but iit is to be understood that such detailed
descriptions are not to be taken in a limiting sense.
Referring to the drawings:
FIG. 1 is a view partly in longitudinal section and partly in
elevation showing one form of the running tool and packing
apparatus connected to the casing hanger which has been lowered
into a subaqueous wellhead housing on a running pipe string, but
prior to operation of the running tool;
FIG. 2 is an enlarged fragmentary detail view in longitudinal
section, as taken on the line 2--2 of FIG. 1;
FIG. 3 is a detail transverse section, as taken on the line 3--3 of
FIG. 2;
FIG. 4 is a detail transverse section, as taken on the line 4--4 of
FIG. 2;
FIG. 5 is a fragmentary view in vertical section, as taken on the
line 5--5 of FIG. 3;
FIG. 6 is a fragmentary view in vertical section, as taken on the
line 6--6 of FIG. 3;
FIG. 7 is a fragmentary view in trasverse section, as taken on the
line 7--7 of FIG. 5;
FIG. 8 is a view in longitudinal section, generally corresponding
with FIG. 2, but showing the packing packed off by fluid pressure
applied to the running tool through the running string;
FIG. 9 is a view generally corresponding with FIG. 8, but showing
the packing locking means actuated to the locking condition in
response to test pressure applied to the housing;
FIG. 10 is a view in longitudinal section, generally corresponding
with FIG. 2, showing the packing setting means held in an upper
position by fluid pressure; and
FIG. 11 is a view partly in elevation and partly in longitudinal
section, showing another form of the running tool.
In the drilling and completion of wells, such as oil and gas wells,
form vessels on a body of water, the blowout preventer equipment
and casing hanger equipment are located and supported on in a base
mounted on the floor of a body of water. The well casing is
supported by a wellhead housing, and a marine riser pipe extends
downwardly from the vessel to the blowout preventer which is
connected to the wellhead housing, all as is well known.
As seen in the drawings, referring first to the embodiment of FIGS.
1 through 7, the wellhead housing H has a casing hanger body C
landed therein and supported upon an upwardly facing seat or
shoulder 10. The casing hanger C has suitable passages 13 whereby
circulating and cementing operations can be conducted in the usual
manner by the displacement of cement downwardly through the casing,
fluid in the well being displaced upwardly through the passages 13
and through an annular space 14 defined between the cylindrical
inner wall 15 of the housing H and the opposing cylindrical wall 16
of the casing hanger C.
A seal is provided between the opposing cylindrical walls 15 and 16
after the cementing operation is completed by setting a packing P
in the annular space 14 in sealing engagement between the opposing
cylindrical walls 15 and 16 and securely locking the packing in
packed off condition by locking means L. The casing hanger C, the
packing means P, and the locking means L are lowered from the
drilling vessel on a running and setting tool T which is connected
at 17 to a running pipe string R.
The casing hanger C supports at 18 a string of casing 19 which is
adapted to extend downwardly into the well and be supported by the
casing hanger on a support collar 20 threadedly connected at 21 to
the casing hanger body and engageable with an upwardly facing
tapered seat 22 in the wellhead housing H. Above the seat 22 the
wellhead housing H has a circumferentially extended locking groove
23 adapted, as will be later described, to receive a locking ring
24 above the seating collar 20, whereby the casing hanger is locked
against upward movement in the housing H. Typically, the casing
hanger C comprises a main body 25 provided with an internal
cylindrical bore 26 above which is a left hand thread 27. Another
thread 28 extends about the upper end of the upper body section 29
of the casing hanger C. Either of the threads 27 or 28 is adapted
for engagement by suitable running tools. In the present case, the
running tool T has a lower body section 30 provided with a thread
31 engaged with the internal left hand thread 27 within the casing
hanger C, whereby, as will be later described, the casing hanger
with the casing 19 depending therefrom can be lowered into the well
and seated in the wellhead housing H on the running tool T. The
body section 30 of the tool T also has a cylindrical section 30a
provided with side ring seals 32 engageable in the bore 26 of the
casing hanger C.
The running tool T not only supports the casing hanger C, but also
the packing means P and the locking means L as more particularly
shown in FIG. 2.
The packing P includes a lower abutment ring or collar 33 and an
annular body 34 of resiliently deformable elastomeric sealing
material connected by a dove-tailed connection 35 to the lower ring
33, and by a corresponding upper dove-tailed connection 36 with a
packing support sleeve 37. The packing body 34 is deformable
outwardly and inwardly into sealing engagement with the opposed
cylindrical walls 15 and 16, respectively, of the housing H and the
casing hanger C upon axial deformation of the packing body. Such a
packing is more fully disclosed in U.S. Pat. No. 3,797,864, granted
Mar. 18, 1974, for COMBINED METAL AND ELASTOMER SEAL.
The packing support sleeve 37, at a location above the packing 34,
has an internal upwardly facing shoulder or seat 38 on which rests
a split resilient lock ring 39 which is normally of such diameter
as to pass downwardly over the upwardly extended annular section 29
of the casing hanger C. This casing hanger section 29 is undercut
on its outer periphery at 40 to provide a groove, or, as shown in
this specific embodiment, a downwardly and inwardly tapered annular
surface adapted to receive the correspondingly downwardly and
inwardly tapered side 41 of the lock ring 39, when the latter is
deformed inwardly from its normally expanded condition of FIG. 2 to
its contracted or locking position of FIG. 9. In order to effect
locking contraction of the lock ring 39 a lock ring actuator 42 is
provided. This lock ring actuator is in the form of an annular
wedge having an outer cylindrical wall 43 slidably disposed within
the packing support sleeve 37 and an inner downwardly and outwardly
tapered wedge surface 44 opposed to and engageable with the outer
downwardly and outwardly tapered surface 45 of the lock ring 39,
whereby upon downward movement of the actuator 42 within the
support sleeve 37 the lock ring 39 will be wedged or cammed
circumferentially inwardly to the locking position with the locking
surface 40 of the casing hanger C. The angles of the surfaces 44
and 45 of the actuator ring 42 and the lock ring 39, respectively,
are selected to be locking wedge angles, so that once the wedge
action has deformed and locked the lock ring in place, the actuator
42 must be forcefully retracted before the lock ring can be
released. Accordingly, the actuator 42 has an internally undercut
neck 46 at its upper extremity and an internal fishing or
retrieving shoulder 47 adapted to be engaged by a pulling tool,
such as the wedge lock pulling tool of my copending application
Ser. No. 475,586, filed June 3, 1974, for RETRIEVING TOOL FOR
WELLHEAD PACKING.
During the lowering of the packing and the locking assembly through
the riser pipe and into the wellhead housing H, and during the
initial packing off of the packing P, the actuating wedge 42 is
held in an upper inoperative position by releasable means such as
one or more shear pins 48 which interconnect the actuator 42 to the
packing support sleeve 37. These shear pins are selected so that
they will retain the actuator 42 in the initial position until the
packing is fully set, and a downward force is applied to the
actuating wedge 42 to shear the pins 48 enabling downward locking
movement of the actuator wedge 42.
Referring more particularly to the running tool T, it has a tubular
neck 50 extending upwardly from a make-up shoulder 51 above the
lower body section 30. An inner body section or cylinder 52 extends
upwardly from the neck 50 and has the threaded connection 17 with
the running string R. An outer body assembly 53 is carried by the
inner body section 52 and includes a supporting sleeve and cylinder
head 54 fixedly or threadedly connected at 54a to the inner body
52, and an external cylinder sleeve 55 which carries a packing
actuator sleeve 56 threaded at 57 to the outer cylinder sleeve
55.
The cylinder head 54 has an inner side ring seal 58 engaged with
the inner body 52 and an outer side ring seal 59 engaged within an
upper bore 60 of the outer cylinder sleeve 55 above a number of
circumferentially spaced upper ports 61 which extend from the bore
62 in the tool inner body into the space or piston chamber 63
defined between the inner body section 52 and the outer cylinder
sleeve 55. At the lower end of the chamber 63 the body section 52
has a side ring seal 64 slidably engaged with the inner cylindrical
wall of the cylinder sleeve 55 below a number of circumferentially
spaced lower ports 65 which also extend between the body bore 62
and the chamber 63. Reciprocable in the chamber 63 is an annular
piston 66 carried by the cylinder sleeve 55 and having a side ring
seal 67 slidably engaging the body section 52.
As previously indicated, fluid circulation and casing cementing
operations are performed by displacing fluid and cement downwardly
through the running string R and the tool T. In order to protect
the piston chamber 63 from dirty or cementitious fluids, a
protector sleeve 68 is disposed in the body bore 62 and spans the
ports 61 and 64 to normally close the ports. This protector sleeve
has an external seating shoulder 69 engageable with an internal
shoulder in the bore 62 and an upper seal ring 70 engageable in the
bore 62. When it is desired to operate the tool T, as will be later
described, the protector sleeve 68 is pulled by the usual wireline
fishing tool (not shown) having gripping means engageable with an
internal fishing shoulder 71 adjacent to the upper end of the
sleeve 68.
As previously indicated, the outer body assembly 53 includes the
packing actuator sleeve 56 which has a cylindrical skirt portion 75
extending downwardly and disposed in abutting engagement with the
upper end 76 of the packing supporting sleeve 37. This upper end 76
of the sleeve 37 is releasably connected to the lower end of the
cylinder sleeve 55 by a number of circumferentially spaced shear
pins 77a which normally connect the packing supporting sleeve 37 to
the cylinder sleeve 55 for simultaneous movement as the cylinder
sleeve 55 moves downwardly in response to the application of fluid
under pressure to the piston chamber 63 above the piston 66, as
will be later described. Disposed between the packing actuator
sleeve 56 and the outer periphery of the outer cylinder sleeve 55
is a differential actuator piston 77 of annular form, this piston
having an upper section 78 of major diameter disposed between the
inner cylindrical wall 79 of the sleeve 56 and the outer
cylindrical wall 80 of the cylinder sleeve 55 and a lower minor
diameter section 81 disposed between the actuator sleeve wall 79
and an enlarged diameter section 82 of the cylinder sleeve 55.
Depending from the differential piston 77, as best seen in FIGS. 2,
3 and 11, is a plurality of circumferentially spaced fingers 83
which extend downwardly through correspondingly circumferentially
spaced and longitudinally extended slots 84 formed on the outer
periphery of the cylinder sleeve 55. The lower ends 85 of the
fingers 83 extend into abutting engagement with the upper end of
the locking wedge ring 42 so that upon downward actuation of the
piston 77 the fingers 83 will be forced downwardly, forcing the
wedge ring 42 downwardly, to lock the packing in sealing condition,
as will be later described.
A pressure chamber 86 is defined between the actuator piston 77 and
the cylinder sleeve 55 between an upper seal ring 87 and a lower
seal ring 88, respectively, disposed between the upper large end
section 78 of the piston 77 and the smaller diameter lower section
81 of the piston 77 and the cylinder sleeve 55, whereby a
differential area 89 is provided on the piston 77, facing downardly
and exposed to pressure in the chamber 86 to normally hold the
piston 77 in its upper position. The piston 77 is adapted to be
actuated downwardly under the influence of pressure fluid action on
its larger upper end area which is exposed through a suitable
number of apertures 90 in the upper end of the actuator sleeve 56.
Such pressure fluid is applied to the upper end of the piston 77,
as will be later described.
As previously indicated, the casing hanger C and the packing P are
landed in the wellhead housing H in the initial condition as seen
in FIGS. 1 through 7, and thereafter fluid is circulated downwardly
through the running string R, the casing 19, and thence upwardly
through the passages 13, bypassing the running tool T. To
facilitate such fluid bypass the running tool T is provided with a
number of circumferentially spaced bypass flow passages. In the
present form, such flow passages are formed at 91 through the
cylindrical sleeve 55. One of such flow passages 91a as seen in
FIG. 3, 5 and 7 is plugged by a suitable plug 92 at its upper end
and has a filler valve 93 at its lower end, whereby the passage 91a
is adapted, while the apparatus is on the drilling rig platform, to
be filled with a compressible fluid, such as air, such pressurized
air finding access through a radial port 94 in the cylinder sleeve
55 to the previously described chamber 86, so as to act upwardly on
the differential area 89 of the actuator piston 77 to hold the
latter in its upper position. It is apparent that the air in the
chamber 86 acts as an air spring which must be overcome before the
actuator piston 77 can be moved downwardly.
In operation, when it is desired to set the packing P, as shown in
FIG. 8, and lock the packing in place as shown in FIG. 9, the
apparatus functions as follows. Initially, the cylinder sleeve 55
is held in the upper position of FIG. 2 by a suitable number of
shear pins 55a which releasably interconnect the cylinder sleeve 55
with the cylinder head 54. Following the conduct of the cementing
operations, the protector sleeve 68 is pulled, and a dart 100, as
seen in FIG. 8, is dropped into the running string R and lands upon
the shoulder 69 formed within the body shore 62. The dart has
suitable side ring seals 101 sealingly engageable in the bore 62
below an annular groove 102 formed in the body of the dart and
communicating with a flow passage 103 which opens at the top of the
dart. When the dart 100 is seated the groove 102 communicates with
the ports 61 through the body section 52 above the actuator piston
66. Thus, with the dart seated fluid pressure supplied through the
running string R is applied to the piston 66 in the piston chamber
63 to force the cylinder sleeve 55 downwardly after shearing the
upper shear pins 55a. The cylinder sleeve 55 and the actuating
sleeve 56, together with the packing supporting sleeve 37 move
downwardly simultaneously to the position of FIG. 8, at which the
packing sleeve 34 is deformed into sealing engagement between the
opposing housing and hanger walls 15 and 16. As the packing sleeve
34 is being deformed, the lower ring 33 thereon engages and cams
the casing hanger locking ring 24 outwardly into the locking groove
23.
With the apparatus in this condition a preliminary pressure check
can be made by closing the blowout preventer on the running string
R and supplying test pressure fluid to the wellhead housing H
through the usual kill or choke line of the blowout preventer. This
test pressure is applied to the packing while the initial pre-load
which deformed the packing is maintained by holding the pressure in
the running string which is applicable to the packing actuator
piston 66.
As the test pressure is increased, the pressure acts on the
differential area of the locking actuator sleeve or piston 78
overcoming the pressure in chamber 86 acting upwardly on the piston
area 89, and overcoming the shear pins 48 which connect the locking
wedge or actuator ring 42 to the packing support sleeve 37. When
the pins 48 are sheared, the locking wedge ring 42 is shifted
downwardly to the position of FIG. 9, from the position of FIG. 8.
The opposed wedge surfaces 44 and 45 on the wedge ring and the lock
ring 39 deform the split lock ring circumferentially inwardly into
the locking position in engagement with the locking shoulder or
surface 40 on the casing hanger C, whereby the packing means P is
securely locked in place by the locking means L.
Thereafter, the running tool T is disconnected from the casing
hanger by right hand rotation of the running string R which will
break left hand threaded connection 27, 31 between the casing
hanger and the body of the tool. The running string and tool are
then lifted. When the inner body neck 50 shoulders against and
picks up the actuator piston 66, the outer cylinder sleeve 55 will
be pulled free from the packing support sleeve 37, as the shear
pins 77a are sheared.
It may occur that, due to cement or other material being present in
the annular space 14 between the casing hanger and the wellhead
housing, the packing does not properly seal and resist pressure
testing. Under these circumstances, it may be desirable to pull the
packing means free from the annulus 14, and possibly retrieve the
running tool T with the packing thereon to allow remedial washing
or cleaning operations.
To accomplish this a release dart 200 is provided, as shown in FIG.
10. The dart 200, like the dart 100, has a retrieving head adapted
to land on the shoulder 69 in the bore of the tool body section 52.
The release dart 200 is elongated so as to span the ports 61 and 65
in the body section 52. Above the ports 61, the dart 200 has upper
side ring seals 201 sealingly engageable in the body in the body
bore 62. Below the lower ports 65, the dart 200 has side ring seals
202 sealingly engaged in the body bore 62. Between the ports 61 and
65, the dart 200 has intermediate side ring seals 203 which
sealingly engage in the body bore 62. An annulus 204 in the dart
200 communicates with the lower body ports 65, and a passage 205
leads from the annulus 204 to the top of the dart, whereby pressure
fluid supplied through the running string is applicable to the
piston chamber 63 below the actuator piston 66 of the cylinder
sleeve 55. To enable the exhaust of fluid from the chamber 63 above
the piston 66, the dart 200 has another annulus 206 communicating
with the upper body ports 61, and a discharge passage 207 leads
from the annulus 206 downwardly to the bottom of the dart.
Upon completion of remedial or washing work, the tool T is again
operable, upon removal of the dart 200 and seating of the dart 100,
to set and lock the packing means in place in the annulus 14, after
pressure testing.
It will be recognized that the threaded joint 27, 31 between the
running tool lower body 30 and the casing hanger C is a connection
which is easily released by rotation of the running string R. In
FIG. 11 a modified connector means 300 is shown for connecting the
tool T with the casing hanger C. This connection means 300 is
releasable without requiring rotation of the running string R.
In FIG. 11 the casing hanger C is landed in the wellhead housing.
The connector means 300 includes a lower conical nose 301
threadedly connected at 302 to a reduced section 303 extending
downwardly from the setting tool body. The lower nose 301 has an
upstanding hollow body 34 which carries the side ring seals 305
sealingly engageable in the bore 26 of the casing hanger C. At its
upper end, the body section 304 has one or more longitudinally
extended keys 306 engageable in a key way 307 extending through the
internal threads 27 of the casing hanger. Above the seals 305 the
body section 304 has a number of circumferentially spaced radial
windows or openings 308 in which are reciprocable a corresponding
number of latching dogs 309. These latching dogs are adapted, upon
outward movement, to engage in a locking groove 310 formed in the
casing hanger body. The locking groove 310 would be used for the
locking ring or lockdown dogs of a tubing hanger, as is well known,
to lock it to the casing hanger or such groove may be used when
running the hanger on the running tools. A piston sleeve 311 is
disposed about the tool body section 303 and has a central flange
312 engageable with the dogs 309 to hold them outwardly in the
locking position of FIG. 11.
A lower piston chamber 313 is formed below the piston sleeve 311 by
a side ring seal 314, engaged between the outer periphery of the
piston sleeve and the body 304 of the connector, and a seal 315 in
the threaded connection 302. The tool body section 303 has a lower
plurality of circumferentially spaced ports 316 leading from the
tool body bore 62 to the annular clearance 317 between the piston
sleeve 311 and the tool body section 303. An upper piston chamber
318 is formed by an upper seal ring 319 between the bodies 303 and
304, a lower seal ring 320, between the body 304 and the piston
sleeve 311, and another seal ring 321 between the body 303 and the
inside diameter of the piston sleeve 311. An upper plurality of
circumferentially spaced ports 322 lead from the body bore 62 to
the upper chamber 318.
During the running and cementing operations previously described,
the ports 316 and 322 are closed by a downward extension 368 of the
protector sleeve 68. When the protector sleeve 68 is pulled, the
ports 316 and 322 are open. Since the piston sleeve 311 is a
balanced piston, its position is not affected by fluid entering
both piston chambers 313 and 318.
As is apparent, without requiring further description or
illustration, when it is desired that the running tool T be
released from the casing hanger c following setting and locking of
the packing P in the annulus 14, a dart (not shown) can be landed
on a seating shoulder 323, such dart having suitable seals and
porting to allow discharge from the upper piston chamber 318 and to
enable the application of operating fluid pressure to the lower
chamber 313, so that the piston sleeve 311 will be shifted to an
upper position at which the dogs 309 are free to be shifted
inwardly by camming surface 324 when the tool is pulled
upwardly.
* * * * *