U.S. patent number 3,592,489 [Application Number 04/807,730] was granted by the patent office on 1971-07-13 for housings with contractable well casing hanger seats.
This patent grant is currently assigned to Vetco Offshore Industries, Inc.. Invention is credited to Benton F. Baugh, Carl F. Huntsinger, Bobby H. Nelson.
United States Patent |
3,592,489 |
Baugh , et al. |
July 13, 1971 |
**Please see images for:
( Certificate of Correction ) ** |
HOUSINGS WITH CONTRACTABLE WELL CASING HANGER SEATS
Abstract
A housing having a seat for a casing hanger, which seat is
initially in an outer or expanded position to avoid restrictions
projecting into the housing. Fluid pressure acts on a piston device
to effect contraction or constriction of the seat, causing it to
project into the housing and serve as a landing shoulder for a
casing hanger.
Inventors: |
Baugh; Benton F. (Houston,
TX), Nelson; Bobby H. (Houston, TX), Huntsinger; Carl
F. (Ojai, CA) |
Assignee: |
Vetco Offshore Industries, Inc.
(Ventura, CA)
|
Family
ID: |
25197068 |
Appl.
No.: |
04/807,730 |
Filed: |
March 17, 1969 |
Current U.S.
Class: |
285/18; 285/315;
285/321; 285/123.3 |
Current CPC
Class: |
E21B
33/043 (20130101) |
Current International
Class: |
E21B
33/043 (20060101); E21B 33/03 (20060101); F16l
055/00 () |
Field of
Search: |
;166/.6,86,88
;285/18,141,315,321 |
References Cited
[Referenced By]
U.S. Patent Documents
Foreign Patent Documents
Primary Examiner: Arola; Dave W.
Claims
We claim:
1. In hanger apparatus for suspending a casing string in a well
bore: a housing having a passage through which the casing string
can be run and lowered in the well bore, said housing having
axially spaced upper and lower guide surfaces normal to the axis of
said housing; a hanger seat in said housing between said surfaces
and having upper and lower guide surfaces normal to the axis of
said housing a slidably engaging said housing guide surfaces to
confine said seat for nonaxial radial movement, said seat initially
occupying an outer position substantially completely free from the
housing passage; and means for shifting said hanger seat radially
along said housing guide surfaces partially inwardly of said
passage to provide a support for a hanger connected to the upper
portion of the casing string; said hanger seat comprising a split
ring structure including an outer ring and an inner ring coupled to
said outer ring.
2. In hanger apparatus as defined in claim 1; wherein said hanger
seat comprises an inherently expandable split ring structure.
3. In hanger apparatus as defined in claim 1; wherein said shifting
means comprises cylinder and piston means, and means for conducting
fluid under pressure into said cylinder and piston means to actuate
the same.
4. In hanger apparatus for suspending a casing string in a well
bore: a housing having a passage through which the casing string
can be run and lowered in the well bore, said housing having
axially spaced upper and lower guide surfaces normal to the axis of
said housing; a hangar seat in said housing between said surfaces
and having upper and lower guide surfaces normal to the axis of
said housing and slidably engaging said housing guide surfaces to
confine said seat for nonaxial radial movement, said seat initially
occupying an outer position substantially completely free from the
housing passage; and means for shifting said hanger seat radially
along said housing guide surfaces partially inwardly of said
passage to provide a support for a hanger connected to the upper
portion of the casing string; said shifting means including an
actuator having axially spaced cam surfaces thereon axially
separated from one another and engaging said seat and shiftable
axially of said housing and seat to shift said seat laterally
inwardly of said housing passage, one of said cam surfaces being
disposed under the other of said cam surfaces.
5. In hanger apparatus as defined in claim 4; wherein said hanger
seat comprises a split ring structure; said cam surfaces engaging
said split ring structure and shiftable axially of said housing and
split ring structure to shift said split ring structure laterally
inwardly of said housing passage.
6. In hanger apparatus as defined in claim 4; wherein said shifting
means further comprises a cylinder in said housing, a piston in
said cylinder operatively associated with said actuator, and means
for conducting fluid under pressure to said cylinder to shift said
piston and actuator axially of said housing and seat and cause said
actuator to shift said seat laterally inwardly of said housing
passage.
7. In hanger apparatus as defined in claim 4; said actuator and
seat having surfaces substantially parallel to the housing axis
which coengage upon axial shifting of said actuator to retain said
seat inwardly of said housing passage.
8. In hanger apparatus as defined in claim 4; wherein said hanger
seat comprises a split ring structure; said cam surfaces engaging
said split ring structure and shiftable axially of said housing and
split ring structure to shift said split ring structure laterally
inwardly of said housing passage; said actuator and split ring
structure having surfaces substantially parallel to the housing
axis which coengage upon axial shifting of said actuator to retain
said split ring structure inwardly of said housing passage.
9. In hanger apparatus as defined in claim 4; wherein said hanger
seat comprises a split ring structure; said cam surfaces engaging
said split ring structure, a cylinder in said housing, a piston in
said cylinder operatively associated with said actuator, and means
for conducting fluid under pressure to said cylinder to shift said
piston and actuator axially of said housing and split ring
structure and cause said actuator to shift said split ring
structure laterally inwardly of said housing passage.
10. In hanger apparatus as defined in claim 4; wherein said hanger
seat comprises a split ring structure; said cam surfaces engaging
said split ring structure, a cylinder in said housing, a piston in
said cylinder operatively associated with said actuator, and means
for conducting fluid under pressure to said cylinder to shift said
piston and actuator axially of said housing and split ring
structure and cause said actuator to shift said split ring
structure laterally inwardly of said housing passage; said actuator
and split ring structure having surfaces substantially parallel to
the housing axis which coengage upon axial shift of said actuator
to retain said split ring structure inwardly of said housing
passage.
11. In hanger apparatus for suspending a casing string in a well
bore: a housing having a passage through which the casing string
can be run and lowered in the well bore, said housing having
axially spaced upper and lower guide surfaces normal to the axis of
said housing; a hanger seat in said housing between said surfaces
and having upper and lower guide surfaces normal to the axis of
said housing and slidably engaging said housing guide surfaces to
confine said seat for nonaxial radial movement, said seat initially
occupying an outer position substantially completely free from the
housing passage; said housing having an annular cylinder; an
annular piston in said cylinder; an annular actuator in said
housing operatively associated with said piston and hanger seat;
and means for conducting fluid under pressure into said cylinder to
shift said piston axially in said cylinder and said actuator
axially of said seat to shift said seat radially along said housing
guide surfaces partially inwardly of said passage to provide a
support for a hanger connected to the upper portion of the casing
string; said hanger seat comprising an inherently expandable split
ring structure; said actuator encompassing said ring structure and
having one or more cam surfaces thereon engaging said structure to
constrict said split ring structure inwardly of said housing
passage upon axial movement of said actuator along said split ring
structure, said split ring structure inherently expanding to said
outer position prior to axial movement of said actuator to
constrict said split ring structure. 12In hanger apparatus as
defined in claim 11; said actuator and split ring structure having
surfaces substantially parallel to the housing axis which coengage
upon axial shifting of said actuator to
retain said split ring structure inwardly of said housing passage.
13. In hanger apparatus for suspending a casing string in a well
bore: a housing having a passage through which the casing string
can be run and lowered in the well bore, said housing having
axially spaced upper and lower guide surfaces normal to the axis of
said housing; a hanger seat in said housing between said surfaces
and having upper and lower guide surfaces normal to to the axis of
said housing and slidably engaging said housing guide surfaces to
confine said seat for nonaxial radial movement, said seat initially
occupying an outer position substantially completely free from the
housing passage; and means for shifting said hanger seat radially
along said housing guide surfaces partially inwardly of said
passage to provide a support for a hanger connected to the upper
portion of the casing string; said shifting means including an
actuator having axially spaced cam surfaces thereon axially
separated from one another and engaging companion axially spaced
cam surfaces on said seat axially separated from one another, said
actuator being shiftable axially of said housing and seat to cause
said actuator cam surfaces to slide along said seat cam surfaces
and shift said seat radially inwardly of said housing passage, one
of said actuator cam surfaces being disposed under another of
said actuator cam surfaces. 14. In hanger apparatus as defined in
claim 13; said actuator occupying a lower position with said seat
in its outer position, said actuator being shiftable upwardly of
said housing and seat to cause said actuator cam surfaces to slide
upwardly along said seat cam surfaces and shift said seat radially
inwardly of said housing passage.
In hanger apparatus as defined in claim 13; said actuator and seat
having surfaces substantially parallel to the housing axis which
coengage upon axial shifting of said actuator to retain said seat
inwardly of said
housing passage. 16. IN hanger apparatus as defined in claim 13;
said actuator occupying a lower position with said seat in its
outer position, said actuator being shiftable upwardly of said
housing and seat to cause said actuator cam surfaces to slide
upwardly along said seat cam surfaces and shift said seat radially
inwardly of said housing passage; said actuator and seat having
surfaces substantially parallel to the housing axis which coengage
upon axial shifting of said actuator to retain said
seat inwardly of said housing passage. 17. In hanger apparatus for
suspending a casing string in a well bore: a housing having a
passage through which the casing string can be run and lowered in
the well bore, said housing having axially spaced upper and lower
guide surfaces normal to the axis of said housing; a hanger seat in
said housing between said surfaces and having upper and lower guide
surfaces normal to the axis of said housing and slidably engaging
said housing guide surfaces to confine said seat for nonaxial
radial movement, said seat initially occupying an outer position
substantially completely free from the housing passage; said
housing having an annular cylinder; an annular piston in said
cylinder; an annular actuator in said housing operatively
associated with said piston and hanger seat; and means for
conducting fluid under pressure into said cylinder to shift said
piston axially in said cylinder and said actuator axially of said
seat to shift said seat radially along said housing guide surfaces
partially inwardly of said passage to provide a support for a
hanger connected to the upper portion of the casing string; said
hanger seat comprising an inherently expandable split ring
structure; said actuator encompassing said ring structure and
having axially spaced cam surfaces thereon engaging companion
axially spaced cam surfaces on said ring structure, said actuator
being shiftable axially of said housing and ring structure to cause
said actuator cam surfaces to slide along said ring structure cam
surfaces and constrict said split ring structure radially inwardly
of said housing passage, said split ring structure inherently
expanding to said outer position prior to axial movement of
said actuator to constrict said split ring structure. 18. In hanger
apparatus as defined in claim 17; said actuator occupying a lower
position with said split ring structure in its outer position
substantially free of said housing passage, said actuator being
shiftable upwardly of said housing and ring structure to cause said
actuator cam surfaces to slide upwardly along said ring structure
cam surfaces and constrict said ring
structure radially inwardly of said housing passage. 19. In hanger
apparatus as defined in claim 17; said actuator and split ring
structure having surfaces substantially parallel to the housing
axis which coengage upon axial shifting of said actuator to retain
said split ring structure
inwardly of said housing passage. 20. In hanger apparatus as
defined in claim 17; said actuator occupying a lower position with
said split ring structure in its outer position substantially free
of said housing passage, said actuator being shiftable upwardly of
said housing a ring structure to cause said actuator cam surfaces
to slide upwardly along said ring structure cam surfaces and
constrict said ring structure radially inwardly of said housing
passage; said actuator and split ring structure having surfaces
substantially parallel to the housing axis which coengage upon
axial shifting of said actuator to retain said split ring structure
inwardly of said housing passage.
Description
The present invention relates to well bore apparatus, and more
particularly to apparatus for hanging casings from a housing at the
top of the well bore.
Present housings for hanging casing string in well bores,
particularly those employed in offshore drilling, have a landing
shoulder that reduces the bore diameter through the housing to a
substantial extent. This requires the well bore to be underreamed
before the desired diameter of casing can be run through the
housing into the well bore and supported properly from the housing.
In the absence of underreaming, it has been necessary to run
smaller casing through the housing and into the well bore than the
desired size.
The foregoing difficulties are solved by virtue of the present
invention. The casing hanger seat is initially carried in the
housing in an outer or expanded condition, thus effecting only a
slight restriction, if any, through the housing passage, and
thereby allowing a hole opener of an appropriate diameter to be run
with the customary well drilling bit. Accordingly, a well bore
diameter is drilled that is large enough to permit running of the
desired diameter of casing through the housing and into the well
bore, the casing being of a larger diameter than was heretofore
obtained when underreaming was not performed.
Following the drilling of the hole to the desired larger diameter,
the hanger seat is contracted or constricted to the required seat
diameter to provide a landing shoulder through which the desired
diameter of casing can be run and on which the hanger body can be
landed for the purpose of supporting the well casing in the well
bore. With the casing so supported, it can be cemented in place,
appropriate circulating fluid being bypassed around the constricted
hanger seat until the bypass passage is to be closed by devices
that, per se, constitute no part of the present invention.
The hanger seat can be positively locked in its contracted or
constricted position. It can be contracted or constricted
hydraulically to form a rigid landing shoulder. After the seat has
been constricted, the apparatus is so constructed and arranged that
the well bore pressure cannot shift the contracted seat from its
constricted position projecting into the well head housing.
For the purpose of reducing the stresses in the seat, it can be
made of a composite construction, such as an inner ring and an
outer ring, for the purpose of allowing standard materials to be
used and to reduce the force required to effect constriction of the
inner and outer rings to the desired internal diameter.
This invention possesses many other advantages, and has other
purposes which may be made more clearly apparent from a
consideration of several forms in which it may be embodied. Such
forms are shown in the drawings accompanying and forming part of
the present specification. These forms will now be described in
detail for the purpose of illustrating the general principles of
the invention; but it is to be understood that such detailed
description is not to be taken in a limiting sense, since the scope
of the invention is best defined by the appended claims.
Referring to the drawings:
FIG. 1 is a longitudinal section through an embodiment of the
apparatus, with its hanger seat in expanded condition;
FIG. 2 is a view similar to FIG. 1, with the seat contracted;
FIG. 3 is an enlarged fragmentary longitudinal section through a
portion of the apparatus of FIG. 1, disclosing the seat in expanded
condition;
FIG. 4 is a view like FIG. 3, illustrating the seat in the
contracted condition of FIG. 2;
FIG. 5 is a longitudinal section through a portion of a modified
form of apparatus, with its seat structure in expanded condition;
and
FIG. 6 is a view like FIG. 5, with the seat structure in contracted
position.
The apparatus illustrated in the drawings is particularly adapted
for use in the drilling of well bores underlying a body of water.
Such well bores may either be drilled from a drilling platform
resting on the ocean floor or from a drilling barge floating in the
water above the well site. For purposes of clarity conventional
well equipment that may have already been installed in the well
bore and at the ocean floor have been omitted from the drawings. In
the present case, a housing 10 is provided which is lowered into
appropriate supporting engagement with a companion housing (not
shown) which will encompass it, the housing having a downwardly
tapering shoulder 11 adapted to engage a companion shoulder in the
housing surrounding it and being locked in set position by an
external split lock ring 12. The housing 10 is disclosed as having
a plurality of inherently contractable split lock rings 13 disposed
in grooves 14 in longitudinal spaced relation to each other, but
such lock ring arrangement forms no part of the present invention,
being shown since they will serve to lock certain equipment run in
the well bore to the housing.
The housing 10 also contains an inherently expandable split seat
ring 15, the inside diameter of which is initially substantially
the same as or only slightly less than the minimum inside diameter
through the housing itself. This split ring is disposed in a
longitudinal space 16 formed between a lower housing section 17,
which is threadedly secured to an upper housing section 18. As
described hereinbelow, the split ring 15 is adapted to be
contracted or constricted so that it projects laterally inwardly of
the inner housing wall 19 and thereby provides a solid seat on
which a casing hanger (not shown) can be supported with casing
suspended therefrom.
The housing sections 17, 18 define an annular cylinder space 29 by
virtue of the fact that the lower section has a cylindrical skirt
21 in spaced relation to a cylindrical wall 22 of the upper housing
section, the cylindrical skirt terminating in an inwardly directed
cylinder head 23 engaging the inner wall 22 of the upper section
18. The upper end 24 of the skirt forms a lower guide shoulder
against which the lower surface 25 of the split seat ring bears and
along which it is laterally slidable. An opposed upper guide
shoulder 26 is formed on the upper section and along which the
upper side 27 of the split seat ring is in slidable engagement.
As was stated above, the split seat ring 15 is initially in its
expanded position, as illustrated in FIGS. 1, 3, being disposed
substantially entirely outwardly of the inner wall 19 of the
housing. Encompassing the split seat ring is a constrictor ring 28
that extends downwardly initially within the upper portion of the
annular cylinder space 29, and which has an inwardly directed upper
flange 30 received within a circumferential external groove 31 in
the split seat ring, the lower portion 32 of the split seat ring 15
projecting into an internal circumferential groove 33 in the
constrictor ring. The upper side 34 of the external ring groove is
inclined in an upward and outward direction and is engaged by a
companion inclined surface 35 of the constrictor ring flange 30.
Similarly, the lower side 36 of the internal constrictor ring
groove 33 is inclined in an upward and outward direction, engaging
a companion external cam surface 37 on the split seat ring. Above
its upper cam surface 34, the split seat ring terminates in an
upwardly facing shoulder 38 located at the lower end of a
longitudinal cylindrical surface 39 of the split seat ring of
smaller diameter than the external diameter of the shoulder 38.
For the purpose of contracting the seat ring 15, the constrictor
ring 28 is shifted upwardly along the split seat ring. Such upward
shifting occurs as a result of hydraulically moving an annular
piston 40, in the annular cylinder space 29 and located below the
constrictor ring 28, in an upward direction, this piston being
separate from the constrictor ring, although in engagement with its
lower end. Fluid under pressure from the drilling platform or
drilling barge is conducted through a suitable line 41 into an
operating port 42 in the housing, which is in communication with a
longitudinal fluid pressure passage 43 that terminates in an inlet
port 44 leading into the lower portion of the cylinder space 29.
The fluid is prevented from leaking upwardly past the piston 40 by
an external seal ring 45 on the piston slidably and sealingly
engaging the inner wall 22 of the outer housing section, and by a
seal ring 46 in the cylinder skirt slidably and sealingly engaging
the inner surface of the piston. Leakage of fluid in a downward
direction from the cylinder space is prevented by a seal ring 47 in
the cylinder head 23 sealingly engaging the inner wall 22 of the
upper housing section.
Initially, the split seat ring 15, which is inherently expandable,
occupies the position disclosed in FIG. 1, in which the constrictor
ring 28 and piston 40 are in their lower positions, and in which
the minimum inside diameter through the split seat ring 15 is only
slightly less than, or no less than, the minimum inside diameter
through the housing 10. The absence of restriction in the housing
(the various lock rings 13 will automatically expand outwardly into
their respective grooves 14 when objects bear against them) permits
the driller to run the appropriate size drilling equipment, such as
drill bits and hole openers, through the seat ring 15 of a much
larger diameter than if the seat projected into the housing, to
drill a well bore of a diameter that will accommodate the required
diameter of casing to be subsequently lowered into the drilled
hole. As an example, if the bore diameter of the housing is 163/4
inches and a landing seat is to be provided of an internal diameter
of 15 5/16 inches, such a landing seat, if provided initially,
would prevent the well bore to be drilled to the desired diameter
to accept 133/8-inch casings, unless the well bore diameter were
enlarged by a subsequent underreaming operation, or the driller
would be forced to run casing smaller than the 133/8-inch diameter
required. In the resent case, the initial inside diameter of the
split seat ring 15 can, by way of example, be 161/2 inches in
diameter, which allows the proper size bit to be run with a
161/4-inch hole opener thereabove, which will provide a hole large
enough to run the desired 133/8-inch casing in the drilled
hole.
When the driller is ready to run the casing, he causes fluid under
pressure from the drilling platform or drilling barge to pass
through the pressure line 41 into the operating port 42 and
longitudinal passage 43, and through the inlet port 44 into the
lower end of the cylinder, which drives the piston 40 upwardly,
forcing the constrictor ring 28 upwardly and camming or
constricting the seat ring 15 inwardly to the extent at which the
upper constrictor ring flange 30 rides past the shoulder 38, at
which time the inner surface 50 of the flange is disposed behind
the ring surface 39 above the shoulder 38, and the lower inner
surface 51 of the constrictor ring 28 is disposed behind the
external surface 52 of the ring below its external groove 31. The
surfaces 39, 50 and 51, 52 are longitudinal and parallel to the
housing axis and will preclude outward expansion of the split seat
ring 15, the shoulder 38 preventing the constrictor ring 28 from
moving downwardly. The upper extent of movement of the constrictor
ring 28 under the action of the hydraulic piston is limited by
engagement of its upper end 53 with housing 10. Thus, a solid
landing shoulder 54, which may taper in a downward direction, is
provided by the upper portion of the seat ring 15, the lower inner
surface 55 of the ring also being tapered or beveled in an upward
direction to permit devices to be moved therethrough without
hanging up on the ring.
After the ring 15 is constricted, the desired diameter casing is
run in the well bore and the casing hanger will land and come to
rest on the tapered landing surface or shoulder 54 of the seat
ring, the lock ring 13 thereabove snapping over the hanger body
(not shown) to preclude its upward movement.
The casing that has been run in the well bore can now be cemented
in place. Circulating fluid may be pumped down the casing string
followed by cement, the circulating fluid passing upwardly around
the casing string and through bypass ports 60 in the lower housing
section 17 communicating with an annular groove or channel 61
formed between the upper and lower housing sections, and thence
through the bypass passages 62 and through upper ports 63 to the
interior of the housing above the lock ring 13 immediately above
the seat ring 15.
After the constrictor ring 28 has been shifted upwardly
hydraulically to its position in which it has contracted the split
seat ring 15 and holds it in such contracted position, the fluid
pressure in the line 41 and the fluid passages 42, 43, 44 and
cylinder space 29 can be relieved, the constricted ring 15
remaining locked in its contracted position. Since the piston 40 is
disconnected from the constrictor ring 28, any fluid pressure in
the housing that might act on its upper surface can do nothing more
than move it downwardly to its lower position in the cylinder 29,
without having any pulling action or effect on the constrictor ring
28, which remains in its upper locking position.
In the form of the invention illustrated in FIGS. 5 and 6,
essentially the same apparatus is illustrated as in the embodiment
described specifically above. However, the split seat ring 15a is
made in two parts; that is, an outer split ring 70 and an inner
split ring 71, both of which are inherently expandable. The outer
split ring 70 bears the same relation to the constrictor ring 28 as
in the other form of the invention, and the minimum bore through
the inner split ring 71 is the same as in the other form of the
invention. The two rings 70, 71 are interlocked to one another by
external teeth 72 on the inner ring meshing with internal teeth 73
of the outer ring, the teeth engaging each other at a slightly
upwardly tapering angle so that downward force imposed on the inner
ring 71 tends to maintain it locked to the outer ring 70, and
upward force on the outer ring tends to maintain it locked to the
inner ring. Downward force on the inner ring 71 is transmitted to
the outer ring 70, and through the latter to the lower guide
shoulder 24 at the upper end of the lower housing section 17.
In all respects, the composite inner and outer rings 70, 71
initially occupy an expanded or lateral outward position, as
illustrated in FIG. 5. Fluid pressure imposed through the port 42
and longitudinal housing passage 43 will move the annular piston 40
and constrictor ring 28 upwardly to expand the composite inner and
outer split rings 70, 71 in an inward direction. If desired, a
check valve 80 can be disposed in the inlet port 44, consisting of
a valve seat 81 engaged by a ball 82 and urged thereagainst by a
helical compression spring 83. Fluid under pressure shifts the ball
82 inwardly against the force of the compression spring 83, the
fluid then passing into the cylinder space 29. Should the fluid
under pressure attempt to leave the cylinder space, the check valve
ball element 82 engages its seat 81 to prevent such reverse
flow.
By making the seat ring 15a of two pieces, that is, of an inner
split seat ring 71 and an outer split seat ring 70, the stresses in
the rings are reduced, to permit standard material to be employed,
since the force required to constrict each of the rings is less
than the force required to constrict an integral ring, as
illustrated in FIGS. 1 to 4.
* * * * *