U.S. patent number 3,779,313 [Application Number 05/160,407] was granted by the patent office on 1973-12-18 for releasable connecting apparatus for subsea wellhead.
This patent grant is currently assigned to Regan Forge & Engineering Company. Invention is credited to Albert Michael Regan.
United States Patent |
3,779,313 |
Regan |
December 18, 1973 |
RELEASABLE CONNECTING APPARATUS FOR SUBSEA WELLHEAD
Abstract
The apparatus has inner and outer members nonrotatably
telescoped together with a driving ring therebetween which in an
extended position of the members is locked to the inner member for
rotation therewith, which in a contracted position of the members
is freed from the members, and which has lower teeth mating with
teeth on a casing hanger whereby when the casing hanger is
suspended over its landing shoulder in a subsea wellhead, in order
to maintain the apparatus in the extended position, right hand
rotation of the string drivingly rotates the casing despite a left
hand threaded attachment between the hanger and the outer member
when the casing hanger engages the landing shoulder, but when the
apparatus contracts to free the drive ring, right hand rotation of
the string unscrews the left hand threaded attachment to release
the apparatus from the casing hanger for withdrawal of the
apparatus.
Inventors: |
Regan; Albert Michael
(Huntington Beach, CA) |
Assignee: |
Regan Forge & Engineering
Company (San Pedro, CA)
|
Family
ID: |
22576782 |
Appl.
No.: |
05/160,407 |
Current U.S.
Class: |
166/360;
166/208 |
Current CPC
Class: |
E21B
33/0415 (20130101); E21B 33/035 (20130101) |
Current International
Class: |
E21B
33/04 (20060101); E21B 33/035 (20060101); E21B
33/03 (20060101); E21b 007/12 () |
Field of
Search: |
;166/.5,208,181,177,135 |
References Cited
[Referenced By]
U.S. Patent Documents
Primary Examiner: Champion; Marvin A.
Assistant Examiner: Favreau; Richard E.
Claims
I claim:
1. An apparatus for releasably connecting an oil well tool to a
tubing string or the like to rotate said tool in a well prior to
landing thereof and which is locked against release of said tool
until said tool is landed at the well, said apparatus
comprising:
inner and outer tubular members mounted together in non-rotative
telescoping relation normally biased into relatively extended
positions thereof, said inner member being connected to a tubing
string and said outer member being threadably connected to an oil
well tool and threadably releasable therefrom upon relative
rotation therebetween;
means for preventing said relative rotation between said outer
member and said tool when said members are relatively extended and
for allowing said relative rotation therebetween when said members
are telescoped inwardly of each other due to lowering of said
tubing string and inner member on the landing of said tool and
outer member so as to cause said outer member to be threadedly
released from said tool upon said relative rotation.
2. An apparatus for releasably connecting an oil well tool to a
tubing string or the like to rotate said tool in a well prior to
landing thereof and which is locked against release of said tool
until said tool is landed at the well, said apparatus
comprising:
a first member having means thereon for connecting to tubing to be
supported and rotated thereby;
a second member mounted to said first member for limited axial
movement relative thereto and to be rotated thereby and having
means thereon for releasably connecting to said tool, said last
named means being releasable from said tool upon relative rotation
therebetween;
torque transmitting means for normally engaging said tool with said
first member in rotative drive relation and for releasing said tool
from said rotative drive relation upon relative axial movement
between said first member and said second member due to landing of
said tool.
3. The apparatus of claim 2 wherein said torque transmitting means
comprises:
a drive ring mounted about said first member for limited axial
movement thereon and having a lower surface provided with means for
drivingly engaging said tool;
spline means provided between said ring and first member for
holding them in non-rotational relation only for a first axial
position of said ring relative to said first member and being
disengaged in a second axial position for said ring relative to
said first member caused by the landing of said tool.
4. The apparatus of claim 3 wherein:
means are provided for normally biasing said first and second
members into a relatively extended relation by which said drive
ring is biased into said first axial position.
5. An oil well tool coupling and running tool assembly for rotating
an oil well tool in a subsea well while supporting the weight of
the tubing and providing for automatic release of the coupling upon
subsequent landing of the tool, said assembly comprising:
a running tool having a landing surface and being rotatably
connected to a tubing string to support the same when landed at a
well;
a coupling member connected to said tubing below said running tool
and releasably coupling to an oil well tool to be rotated and
landed in a well, said coupling having a landing surface
thereon;
a first landing shoulder means at the subsea well for receiving
said running tool and supporting the same during rotation of said
tubing to rotate said tool in the well, said first landing shoulder
means being selectively movable to allow passage of said running
tool thereby;
a second landing shoulder means at said well below said first
landing shoulder for receiving and supporting said running tool
when it is lowered past said first landing shoulder;
a third landing shoulder means at said well below said second
landing shoulder a distance less than the spacing of the landing
surface on said coupling member below the landing surface on said
running tool; and
means associated with said coupling member for allowing release of
said oil well tool from said coupling upon relative rotation
therebetween only when said coupling is landed on said third
landing shoulder.
6. An oil well tool coupling and running tool assembly as in claim
5 wherein:
said coupling member comprises inner and outer telescoping members
normally in protracted relation when said running tool is landed on
said first landing shoulder and retracted relative to each other
when said coupling member is landed on said third landing shoulder
and said running tool is landed on said second landing
shoulder.
7. An oil well tool coupling and running tool assembly as in claim
6 wherein said means associated with said coupling member comprises
a latching means for latching said oil well tool to said tubing to
be rotated thereby when said coupling members are in protracted
position and releases said oil well tool from said tubing when said
members are in said retracted position to allow release of said oil
well tool from said coupling by relative rotation therebetween.
8. An oil tool coupling comprising:
a body member with means for connecting to tubing for rotation
thereby in a given direction;
a tubular member mounted to said body member for limited axial and
non-rotative movement relative thereto having means for connecting
to an oil well tool which is disconnected by rotation of said
tubular member in said given direction relative to said tool;
unthreaded drive ring means for releasably engaging said body
member and said tool to rotate together and for disengaging from
said tool on landing of said tool in a well and consequent relative
axial movement between said body member and tubular member to allow
release of said tubular member from said tool upon further rotation
of said tubing in said given direction.
9. A casing hanger connecting tool adapted to be mounted on the end
of a tubing string run from a floating vessel to a remote subsea
well for rotating an associated casing in the subsea well prior to
landing of the casing hanger at the well and which is automatically
rendered releasable from said casing hanger upon such landing, said
connecting tool comprising:
a tubular body having means at an upper end thereof for mounting
said body on a tubing string;
an outer sleeve member and means for mounting the same on said body
for non-rotative and limited axial movement relative thereto, said
sleeve member having a lower end provided with means for connecting
to or disconnecting from the casing hanger upon relative rotation
therebetween;
a torque transmitting ring for engaging between said body and
casing hanger to rotate said casing hanger in response to rotation
of said body by said tubing string without turning said sleeve
member relative to said casing hanger; and
means for mounting said torque transmitting ring on said body for
limited axial movement between a first position in which said ring
is locked against relative rotation with said body and a second
position in which said ring is free to rotate relative to said
body, said ring being moved relative to said body into said second
position by said casing hanger as said tool is lowered on landing
said casing hanger in the well, selective rotation of said tubing
string thereafter causing release of said sleeve member and said
tool from said casing hanger.
10. A method of releasing an oil well tool from the end of a tubing
string run into a subsea well comprising the steps of:
rotatively threading the oil well tool to a first portion of a
coupling rotatably driven by a tubing string through a
non-rotatable telescoping interconnection therebetween;
locking said oil well tool against relative rotation with said
first portion by interlocking said tool and the tubing string by an
unthreaded second portion of the coupling which is rotatable with
respect to said first portion;
axially displacing said tubing string relative to said second
portion to unlock said tool and first portion by the setting of the
tubing string down upon said coupling when said tool is landed in
said well; and
rotating said tubing string and first portion relative to said
landed tool to rotatively unthread and release the tool form the
coupling.
Description
BACKGROUND OF THE INVENTION
This invention relates to subsea oil well tools and more
particularly to a releasable connecting apparatus for releasable
connecting a casing hanger to a rotatable drill string for rotation
therewith and release therefrom by rotation in the same
direction.
In oil wells, a casing must often be inserted into the hole after
it is drilled, and before production can be started. The purpose of
such a casing is to prevent the wellhole from collapsing during
production. Such a casing will be smaller in diameter than the
drilled wellhole and so after the casing is inserted into the
larger wellhole, the space between the casing outside and the
drilled hole sides is usually filled with concrete. During the
filling of this space with concrete, it is desirable to rotate the
casing in the wellhole to evenly distribute the concrete around the
casing and uniformly fill the space between the casing and the
holes. If this space is not uniformly filled, portions of the
casing will not be supported thereby and may burst upon being
pressurized to halt the oil production of the well while expensive
repairs are made.
The above problems exist in both surface and subsea wells, but in a
subsea well, the upper end of the casing is not directly accessible
and any tool used to rotate the casing must also hold the casing
while it is being lowered into the wellhole and must be releasable
once the casing is positioned to permit removal of the tool from
the subsea well.
BRIEF DESCRIPTION OF THE INVENTION
Therefore it is the primary object of this invention to provide a
novel releasable connecting apparatus for use in a subsea well to
releasably connect a casing or other oil well tool.
Other and additional objects of this invention are to provide such
a releasable connecting apparatus which rotates and releases in the
same direction, to provide such an apparatus which is usable in a
subsea well, to provide such an apparatus which rotates a casing or
other oil well tool as long as the casing is suspended thereby and
which releases the casing when the casing is supported by other
means, and to provide such an apparatus which is inexpensive to
manufacture, easy to assemble, dependable to operate and generally
better than other apparatus for accomplishing this result.
Generally, the apparatus, according to this invention, for
releasably connecting an oil well tool to a string or the like, to
rotate this tool in a well prior to landing thereof and which is
locked against release of said tool until the tool is landed in the
well, includes inner and outer tubular members mounted together in
non-rotative telescoping relationship with the inner member being
connected to the string and with the outer member being threadably
connected to the oil well tool for release therefrom upon relative
rotation therebetween, and means for preventing relative rotation
between the outer member and the tool when the members are
relatively extended and for allowing relative rotation therebetween
when said members are telescoped inwardly due to lowering of the
tubing string and inner member on the landing of the tool. The
means may be a torque transmitting means including a drive ring
mounted about the inner member and having a lower surface for
drivingly engaging the tool, and including spline means between the
ring and the inner member for non-rotatably holding in a first
axial postion and for being disengaged in a second axial position
caused by landing of the tool. A running tool may be provided for
maintaining the tool above its landing position for rotation
thereof.
Generally the method, according to this invention for releasing an
oil well tool from the end of a string run into a subsea well
includes the steps of connecting the oil well tool to a first
portion of a coupling member mounted to and driven by a string for
release by relative rotation therebetween, locking the tool against
relative rotation with said first portion by interlocking the tool
and string by a movable second portion of the coupling, moving the
second portion to unlock the tool and first portion by setting the
tubing string down upon said coupling when the tool is landed in
the well, and rotating the first portion relative the landed tool
to release the tool from the coupling member.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1a and 1b together, are a side elevational view, partially in
section, of a subsea well and wellhead, with a string therein
having the releasable connecting apparatus according to this
invention, and with the casing hanger of the string shown suspended
over its landing shoulder by latch dogs extending from the wellhead
to engage a casing running tool.
FIG. 2 is an enlarged fragmentary side cross-sectional view taken
along the plane II--II of FIG. 1 showing the apparatus in the
extended position and the casing hanger secured thereto suspended
over its landing shoulder for rotation of the casing in the
wellhole.
FIG. 3 is a view similar to FIG. 2 but showing the apparatus in the
contracted position after the casing hanger has landed on its
landing shoulder for rotation of the apparatus to release the
casing hanger therefrom.
FIG. 4 is a fragmentary cross-sectional view taken along the plane
IV--IV of FIG. 2 showing the splining of the drive ring between the
inner and outer members.
FIG. 5 is a fragmentary cross-sectional view taken along the plane
V--V of FIG. 2 showing the splining of the inner and outer members
of the releasable connecting apparatus, according to this
invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring now to the drawings and particularly to FIG. 1, the
releasable connecting apparatus according to this invention is
generally denoted by the number 10. The apparatus 10 is for use
with a subsea wellhole 11 drilled in the ocean floor 12 beneath the
ocean 13 from a ship or barge (not shown) at the surface of the
ocean 13, as is conventional.
The wellhole 11 has located thereover a conventional wellhead 15
which typically includes a drilling template 16 having a central
bore 17 with an upper cup shaped shoulder 18, and lateral passages
19 therethrough to the ocean 13 which have already been filled with
concrete. The drilling template 16 has thereover, a guide post
frame 20 with a downwardly extending cylindrical outer casing 21
joined at the upper end to an intermediate portion 22 having an
outer bowl shaped surface 23 for seating on the shoulder 18 of the
template, and having an inner shoulder 24 for receiving a casing
hanger thereon. The intermediate portion 22 is joined to an upper
rectangular shaped portion 25. The upper portion 25 has vertically
extending guide posts 26 with conical guides 27 therearound and
with cable anchors 28 on the upper ends thereof for anchoring
cables 29 from the ship (not shown) on the surface of the ocean
13.
A Christmas tree unit 30 has lower guide 31 with a lower tubular
protrusion 32 and with central bore 33. The unit 30 also has a seal
34 seated on the upper end of the guide 31 and with a string of
blow-out preventers 35, 36 and 37 mounted thereover and under an
upper guide 38. The lower blow-out preventer 35 has a fluid supply
line 39 and a fluid return line 40 extending therefrom. This unit
30 is lowered from the ship down the cables 27 and onto the guide
post 26 to be centered by the conical guides 27 while the lower
tubular protrusion 31 extends into thhe central bore of the guide
post frame 20.
The upper end of the upper guide 38 has located thereover a pair of
lower guide arms 41 which together with the guide 38, mount
blow-out preventer fluid control lines 42 which control the opening
and closing of the blowout preventers 35, 36 and 37 from the ship
on the surface of ocean 13.
A coupling 43 is provided through the lower guide arms 41 to mount
the upper blow-out preventer 37 to the lower end of a hanger
supporting tool 44. The hanger supporting tool 44 has a two
diameter central bore 45 with the lower portion thereof generally
the same diameter as the bore 32 and the upper portion of a greater
diameter to provide a landing shoulder 46 therebetween. The hanger
supporting tool 44 has a hydraulically operated latch dog 47 near
the upper end thereof. The upper end of the tool 44 is joined to
the lower end of riser 48 from the ship (not shown). A bracket 49
is located around the riser 48 for mounting the fluid lines 39 and
40 to the riser 48.
Extending down the center of the riser 48 and the wellhead
apparatus 15 is a rotatable string 50 including pipes 51 with right
hand threads 52 for connecting together. The lower end of the
lowermost pipe 51 of the string 50 is threaded into a casing
running tool 53 for receiving the latch dog 47 to temporarily
axially locate the casing running tool 53 as is more fully
explained in my copending U.S. Pat. application Ser. No. 160,399,
filed July 7, 1971 and entitled CASING RUNNING TOOL FOR SUBSEA
WELL, filed concurrently herewith. A short length of pipe 54 is
threaded into the lower end of the casing running tool 53 and has
its lower end threaded into the apparatus 10, according to this
invention.
The apparatus 10 has releasably secured thereto as will be more
fully explained later, a casing hanger 55 having a circumferential
rib 56 provided a shoulder 57 for landing on the cup shaped
shoulder 24 of the guide post frame 20. The casing hanger 55 also
has a plurality of grooves 58 in the rib 56 for permitting fluid to
pass between the hanger 55 and the guide post frame 20. The casing
hanger 55 supports a depending inner casing 59 therefrom to extend
down into the wellhole 11 for receiving concrete between the casing
59 and the wellhole 11 to fill the space therebetween. In order to
insure that concrete fills the space between the casing 59 and the
wellhole 11, it is desirable to rotate the casing 59 while the
concrete is being poured into this space. When the concrete has
set, the apparatus 10 of this invention will release the casing
hanger 55 to permit removal of the apparatus 10 and the string 51,
leaving the casing 59 in the wellhole 11.
Generally, the apparatus 10, according to this invention, for
releasably connecting an oil well tool to a string 51 or the like,
to rotate the tool 55 in a well 11 prior to the landing thereof,
and which is locked against release of the tool 55 until the tool
55 is landed in the well 11, includes an inner tubular member 60
and an outer tubular member 70 mounted together in non-rotative
telescoped relation for movement between an extended position and a
contracted position, with the inner number 60 attached to the
lowermost pipe 54 and the outer member 70 rotatably releasable
attached to the tool 55, and includes means 85 for preventing
relative rotation of the tool 55 until the tool 55 has landed and
then for permitting relative rotation to release the tool 55, and
said means 85 having a drive ring 90 between the members 60 and 70
and spline means 105 between the inner member 60 and the drive ring
90 for driving the ring 90 with the inner member 60 in the extended
position and for releasing the drive ring 90 in the contracted
position whereupon the outer member 70 rotates relative the hanger
55. Biasing means 110 including a spring 119 between the members 60
and 70 may be provided for cushioning inward telescoping movement
of the members 60 and 70.
Referring now to FIG. 2 wherein the apparatus 10 is shown in the
extended position, and to FIG. 3 wherein the apparatus 10 is shown
in the contracted position, the inner tubular member 60 has an
outside diameter essentially equal to the outside diameter of the
short pipe 54. The inner tubular member 60 has a central bore 61
having right hand internal threads 62 sized to mate with the
threads of the pipe 54 for threadably attaching the apparatus 10
into the string 50. The upper end of the member 60 has exterior
vertical splines 63 extending downwardly to end midway of the
member 60 in an external, circumferential rib 64. The rib 64 has a
pair of O-ring grooves 65 in the outer surface thereof, in which
are located O-ring seals 66. The external surface of the member 60
has an external groove 67 therein directly below the rib 64. The
member 60 is completed by provision of a circumferential external
notch 68 in the lower end thereof. The inner tubular member 60 is
for being telescoped into an outer tubular member 70.
The outer tubular member 70 of the apparatus 10 is of a diameter
slightly less than the central bore 33 and 45 of the wellhead 15 to
pass therethrough. The member 70 has an upper circumferential
external lip 71, with passages 72 therethrough, for engaging the
sides of bores 33 and 45 as the apparatus 10 passes therethrough to
centrally locate the apparatus 10. The member 70 has a central bore
73 sized to receive the rib 64 of the member 60 snuggly therein and
has an inwardly extending rib 74 with inner splines 75 which as
shown in FIG. 5 mate with the splines 63 of the inner tubular
member 60 for non-rotatably telescoping the members 60 and 70
together. The lower shoulder of the rib 74 engages the upper
shoulder of the rib 64 in the extended position as seen in FIG. 2
to prevent the members 60 and 70 from sliding apart. The outer
member 70 has an inner lower notch 76 with a pair of O-ring grooves
77 therein containing O-ring 78. The lower end of the inner tubular
member 70 has left hand internal threads 79 for threadably mating
with left hand external threads 80 on the upper end of the inner
casing hanger 55 for mounting the hanger 55 and the casing 59
carried thereby to the apparatus 10.
The apparatus 10 is provided with means 85 for preventing relative
rotation of the outer member 70 and the tool 55 when the members 60
and 70 are in the extended position and for permitting relative
rotation therebetween when the members 60 and 70 are telescoped
into the contracted position. In the preferred embodiment of this
invention, the means 85 include torque transmitting means 86 for
normally engaging the tool 55 with the inner member 60 in rotative
drive relation and for releasing the tool 55 from said rotative
drive relation upon relative axial movement of the members 60 and
70 due to the landing of the tool 55.
In the apparatus 10, the torque transmitting means 86 includes a
drive ring 90 having a lower surface 91 with a plurality of
downwardly protruding teeth 92 for mating with teeth 93 formed in
the upper surface of the inner casing hanger 55 to non-rotatively
secure the two together. The drive ring 90 also has an inner upper
notch 94 providing an upwardly facing shoulder 95, and an outer
upper notch 96 sized to mate with the lower notch 76 of the outer
member 70 to locate the drive ring therein. Adjacent the upper end
of the ring 90 is a circumferential upper groove 97. A retainer
ring 98 has a lower flange 99 which mates with the groove 97 to
hold the ring on the upper end of the drive ring 90. Above the
retainer ring 98 are located two ring bearings 100 made of teflon
or other suitable bearing material for separating the ring 90 from
the rib 64 of the inner member 60 when the members 60 and 70 are in
the contracted position as shown in FIG. 3.
The apparatus 10 is provided with spline means 105 between the ring
90 and the inner member 60 for holding them in non-rotational
relation in the extended position of the apparatus 10 and for
disengaging them in the contracted position due to the landing of
the tool 55, to permit relative rotation between the ring 90 and
the inner member 60. The spline means 105 as best seen in FIGS. 2,
3 and 4, includes radially outwardly extending splines 106 on the
inner member just below the groove 67 and radially inwardly
extending mating splines 107 in the drive ring 90 adjacent the
upper end thereof. The splines 107 are of such a length that when
the members 60 and 70 are in the extended position of FIG. 2 that
the splines 107 mate with splines 106 to be locked together and
where the members 60 and 70 are in the contracted position of FIG.
3, the splines 107 are spaced above the splines 106 in the groove
67 to free the ring 90 from the members 60 and 70.
The apparatus 10 may be completed by the provision of biasing means
110 for biasing the members 60 and 70 to the extended position. The
provision of a biasing means 110 is primarily for attaching the
apparatus 10 to the hanger 55 at the surface on the ship (not
shown) as the weight of the hanger 55 and casing 59, supported by
the apparatus 10, will bias the apparatus 10 to the extended
position once the apparatus 10 is positioned in the riser 48. The
biasing means 110, of the illustrative embodiment, includes the
provision of external threads 111 on the upper end of member 60
above the splines 63. An extension 112 has a central bore 113
slightly larger than the pipe 52 and the outer diameter of the
inner member 60. The extension 112 has internal threads 114 on the
lower end thereof mating with the threads 111 adjacent the upper
end of member 60. The extension 112 has an upper outwardly
extending shoulder 115 with a radial threaded hole 116 for set
screw 117 to lock the extension 112 to the short pipe 54 extending
upwardly from the inner member 60. The outer tubular member 70 is
provided with an upper inner notch 118 to provide a space for
receiving the lower end of spring 119, the upper end of which seats
against the shoulder ll5 to bias the inner and outer members 60 and
70 to the extended position of FIG. 2. The biasing of the spring
119 must be overcome for the members 60 and 70 to move to the
contracted position of FIG. 3.
The apparatus 10 is assembled by sliding the bearings 100 and the
drive ring 90 over the lower end of the inner member 60 before the
retainer ring 98 is snapped around the drive ring 90 for engaging
the splines 107 and preventing the drive ring 90 from dropping from
the inner member 60. The O-rings 66 are inserted into the O-ring
grooves 65 and the outer tubular member 70 telescoped down over the
inner tubular member 60 and the drive ring 90 therearound. The
spring 119 is inserted into the notch 118 and the extension 112 is
threaded onto the inner tubular member 60 to bias the members to
the extended position and prevent the outer tubular member 70 from
sliding upwardly off the inner tubular member 60. The assembly of
the apparatus 10 is completed by the insertion of O-rings 78 in
O-ring grooves 77.
The assembled apparatus 10 is attached to the inner casing hanger
55 on the ship while the casing hanger 55 is held at the upper end
of the riser 48, to locate the casing 59 depending therefrom in the
riser 48. The apparatus 10 has the lower end thereof placed on the
upper end of the hanger 55 and the left hand threads 79 and 80
threaded together until interference begins between the teeth 92
and 93. When the interference begins between the teeth 92 and 93,
the inner tubular member 60 is pressed downwardly into the
contracted position, permitting the inner and outer tubular members
60 and 70 to rotate relative to the hanger 55 and the drive ring
90, secured thereto by the interlocking of teeth. When the outer
tubular member 70 is threaded onto the casing hanger 55, the spring
119 is permitted to return the apparatus 10 to the extended
position of FIG. 2 which locks the inner tubular member 60 to the
drive ring 90 locked to the hanger 55.
The short pipe 54 has the lower end thereof threaded into the upper
end of the inner tubular member 60. The set screw 117 is turned
until it engages the pipe surface to lock the pipe 54 to the member
60. The upper end of the short pipe 54 has the casing running tool
53 threaded thereon. The upper end of the casing running tool 53
has threaded therein the lowermost pipe 51 of the rotatable string
50. These tools are now ready to be lowered into the riser 48 and
into the wellhead 15 to locate the inner casing 59 in the wellhole
11.
Initially, the string 50 is lowered until, as seen in FIG. 1, the
groove in the casing running tool 53 is aligned with the latch dog
47. The latch dog 47 is extended into the groove in the tool 53 to
hold the string 50 in a first axial position. In the first axial
position, the shoulder 57 of the inner casing hanger 55 is spaced a
distance above the landing shoulder 24 of the guide post frame 20,
to maintain the apparatus 10 in the extended position of FIG. 2.
The inner casing 59 extends into the wellhole 11, ready for
receiving concrete therearound. The concrete is pumped down both
the supply line 39 into the central bore of the blowout preventor
35, through the passages 72 of the apparatus 10 and through the
grooves 58 in the hanger 55 to pass into the hole 11 around the
casing 59.
In order to assure a uniform filling of the space between the
casing 59 and the wellhole 11 with concrete, the string 51 is
rotated, rotating the apparatus 10 in a right hand direction. Such
right hand rotation of the apparatus 10 would unscrew the left hand
threads 79 and 80 between the outer tubular member 70 and the
hangar 55, except that, as seen in FIG. 2, the splines 106 and 107
are interlocked to rotate the drive ring 90 which is locked by
teeth 92 and 93 to the hanger 55 to prevent such relative rotation.
The rotation of the strings 51 is continued until the space is
uniformly filled with concrete, whereupon the string 50 is raised
slightly and the latch dogs 47 are released. The string 50 is now
lowered until the shoulder 57 of the hanger 55 seats on the
shoulder 24 of the guide post frame 20 where the hanger 55 will be
left to hang the inner casing 59 in the well hole 11
permanently.
To release the apparatus 10 from the hanger 55 after being landed,
the string 50 is allowed to lower until the shoulder of the running
tool 53 seats on the shoulder 46 of the hanger supporting tool 44
whereby the weight of the string 50 moves the apparatus 10 from the
extended position of FIG. 2 to the contracted position of FIG. 3
against the biasing of spring 119. This movement slides the inner
member 60 relative the outer member 70 and the drive ring 90 to
move the splines 107 upwardly out of meshing engagement with the
splines 106 and into the groove 67 to release the drive ring 90
from the inner member 60. This movement also slides the rib 64 down
onto the bearing rings 100, but maintains the driving connection
between the splines 63 and 75 of the inner and outer tubular
members 60 and 70. Continued right hand rotation of the string 50
rotates the inner and outer members 60 and 70 relative the hanger
55 and the released drive ring 90 to unscrew the left hand threads
79 and 80 and separate the hanger 55 from the apparatus 10. Once
the apparatus 10 is unscrewed, it is raised with the drill string
51 up the riser 48, leaving the hanger 55 and the concrete
surrounded inner casing 57 in the wellhole 11. The wellhole 11 is
now ready to receive production tools which will pump the oil
therefrom.
Thus, the releasable connecting apparatus, according to this
invention, is located in a pipe string for a subsea well to secure
a tool therebelow for rotation in one direction before landing and
for release of the tool by rotation in the same direction upon
landing in the wellhead.
* * * * *