U.S. patent number 3,675,713 [Application Number 05/023,864] was granted by the patent office on 1972-07-11 for method and apparatus for separating subsea well conduit couplings from a remote floating vessel.
This patent grant is currently assigned to Regan Forge and Engineering Company. Invention is credited to Bruce J. Watkins.
United States Patent |
3,675,713 |
Watkins |
July 11, 1972 |
METHOD AND APPARATUS FOR SEPARATING SUBSEA WELL CONDUIT COUPLINGS
FROM A REMOTE FLOATING VESSEL
Abstract
A plurality of hydraulic drive means, each including a piston,
piston rod and cylinder for driving the associated piston rod
relative to the associated cylinder upon introduction of hydraulic
fluid under pressure, are provided at a subsea well conduit
coupling having hydraulically actuated latching means therein
including latching dogs cammed out of latching engagement upon
pulling of the conduit upwardly when the latching means is
deactivated, means are provided for mounting each of such drive
means to one of the coupling members, means are provided for
introducing hydraulic fluid from the floating vessel above the well
and coupling into each of the drive means for driving the
associated piston rod relative to the associated cylinder and an
annular drive ring mounted about said one of said coupling members
is connected to each of the hydraulic drive means so that upon
actuation thereof the drive ring is moved coaxially down about said
one coupling member into engagement with the other of said coupling
members and, on continued actuation of such hydraulic drive means,
said drive ring separates the coupling members by forcing them in
coaxial but opposite directions, the associated latching means dogs
being cammed out of latching position and the coupling members
being released to allow raising of the subsea conduit and
consequent release of the vessel from the subsea well. Additional
hydraulic drive means are also provided in association with an
additional drive ring mounted coaxially about and slidable relative
to the aforementioned drive ring for disconnecting hydraulic line
coupling portions connected to said additional drive ring
preparatory to releasing the main coupling members and raising the
associated marine conductor or conduit.
Inventors: |
Watkins; Bruce J. (Palos Verdes
Estates, CA) |
Assignee: |
Regan Forge and Engineering
Company (San Pedro, CA)
|
Family
ID: |
21817649 |
Appl.
No.: |
05/023,864 |
Filed: |
March 30, 1970 |
Current U.S.
Class: |
166/340;
285/18 |
Current CPC
Class: |
E21B
33/038 (20130101); E21B 17/01 (20130101) |
Current International
Class: |
E21B
33/03 (20060101); E21B 17/01 (20060101); E21B
33/038 (20060101); E21B 17/00 (20060101); F21b
033/035 () |
Field of
Search: |
;166/.5,.6 ;285/18 |
References Cited
[Referenced By]
U.S. Patent Documents
Primary Examiner: Leppink; James A.
Claims
I claim:
1. In a subsea well conduit coupling apparatus including a first
coupling member comprising an upstanding wellhead gib means mounted
to wellhead equipment at a subsea well and providing entry to said
well, a second coupling member mounted to a conduit running to an
overhead floating vessel, hydraulically operated latching means for
latching said first and second members together including latch
dogs, a latch dog receiving means, and caming means therebetween
for caming said dogs out of said receiving means upon uncoupling
movement of said members, the improvement comprising the provision
of:
coupling separater means mounted to said coupling apparatus for
moving said members axially away from one another in an uncoupling
direction to back said second coupling member off of said wellhead
gib means and associated wellhead equipment to facilitate pulling
of said conduit and second coupling member from said well upon
actuation thereof; and
actuating means for actuating said coupling separater means from
said vessel.
2. In a subsea well conduit coupling apparatus as in claim 2
further having hydraulic fluid control line couplings provided with
one of said coupling members, said hydraulic line couplings
including male and female coupling portions, the further provision
of:
additional separator means for separating said hydraulic line male
and female coupling portions upon actuation thereof; and
means for actuating said additional separator means from said
vessel to uncouple said portions.
3. In a marine conductor coupling, for a marine conductor run from
a floating vessel to a subsea wellhead, having an upper coupling
member and means for mounting it to the lower end of the marine
conductor conduit, said upper coupling member having a socket
portion, and a lower coupling member comprising an upstanding gib
means at said wellhead upon which said upper coupling member and
marine conductor are landed for providing entry to the subsea well
through said conductor conduit, latch means including latch dogs
mounted on one of said members and means on the other of said
members for receiving said dogs on actuation of said latching means
when said members are coupled and caming means for caming said dogs
outwardly thereof when said latching means is deactivated and said
coupling members are forcibly separated, the improvement comprising
the provision of:
coupling separater means on said coupling for forcibly moving said
upper coupling member and marine conductor conduit axially away
from said wellhead in an uncoupling direction upon actuation
thereof for caming said latching dogs outwardly of said dog
receiving means and at least partially separating said coupling
members to allow pulling of said marine conductor conduit away from
said wellhead and gib means by raising said conductor after said
latch dogs are released; and
actuating means for actuating said coupling separator means from
said vessel.
4. The method of positively releasing a marine conductor conduit
and the associated vessel from which it is run from a subsea well
wherein a coupling member is mounted to a conductor conduit and has
hydraulically actuated latching means for latching said member to
an upstanding gib means at said subsea wellhead, said method
comprising the steps of:
relieving hydraulic pressure holding said latching means in latched
relation;
releasing said marine conductor conduit and associated vessel from
said wellhead by forcing said coupling member back off of said
upstanding gib means by means operable from said floating vessel
above the wellhead sufficiently to cause unlatching of said
latching means and thereafter pulling said conductor conduit
upwardly toward said vessel.
Description
BACKGROUND OF THE INVENTION
In subsea well drilling, production and work over operations it is
generally necessary to run a marine conductor, conduit or riser
from the floating vessel to the subsea wellhead. Such connection of
a riser or marine conductor and additional subsea conduits between
a floating vessel and a subsea wellhead apparatus is illustrated in
my prior U.S. Pat. No. 3,332,484 entitled "Subsea Well Control Tube
Methods and Apparatus." An exemplary form of marine conductor
coupling for coupling such conduits, risers or conductors is
disclosed in my prior U.S. Pat. No. 3,333,870. Heretofore, such
couplings have been separated at their remote subsea locations,
generally adjacent the wellhead, by pulling the associated
conductor, conduit or riser upwardly toward the overhead floating
vessel after associated latching means have been released. In the
latching mechanism of the marine conductor coupling of my U.S. Pat.
No. 3,333,870, and in other present coupling constructions, a
plurality of latching dogs are wedged or blocked into latching
engagement with circumferential notches in a mating connector
element. The release of the associated hydraulically actuated
blocking or wedging means generally merely releases the blocking or
wedging forces applied to the dogs and the actual release of the
latching members or dogs from the complimentary coupling member is
effected through a camming action occurring therebetween when the
coupling members are pulled apart due to the pulling of the
conductor casing or conduit upwardly of the well from the overhead
vessel. Such release of subsea couplings is generally workable
where the floating vessel is positioned directly over the wellhead
so that the pull applied to the conductor or casing from the vessel
acts in a straight line generally running through the vertical axis
of the coupling members.
However, a vessel or platform floating at sea, particularly where
very deep subsea well formations are being drilled or produced,
cannot be maintained directly over the wellhead and tend to drift
or ride laterally away from the wellhead as seen in FIG. 1 of the
appended drawings. When this condition occurs, it can become
impossible to release the vessel from the subsea well by the
present methods of merely pulling the conductor or conduit upwardly
after releasing the associated coupling latching mechanism because
the pull applied to the upper coupling member is at an angle to the
axis of the lower coupling member. The coupling members generally
must be pulled in coaxially but opposite directions in order to cam
the associated latching dogs out of locking engagement and to
release the coupling members. When the pulling forces on the upper
coupling member are at an angle to the axis of the lower coupling
member, a binding, tight condition occurs between the coupling
members, particularly where latching dogs as aforenoted are
employed, which prevents uncoupling of the coupling members located
beneath the sea and perhaps at such a remote or deep area thereof
that it is not possible to send a diver or other equipment down to
effectuate a release of the coupling members. This is particularly
disadvantageous when emmergency conditions demand an immediate
release of the floating vessel from the subsea well and the
coupling members bind and will not release. In such situations the
only recourse for the drilling or production crew on the floating
vessel may be to drop the entire marine conductor or riser from the
vessel and thus loose valuable equipment and create a difficult
re-entry situation.
SUMMARY OF THE INVENTION
It is therefore a primary object of the present invention to
disclose and provide a method and apparatus for separating subsea
well conduit couplings positioned generally adjacent the wellhead
beneath the sea in a positive and forceful manner from the remote
floating vessel so that subsequent drawing or pulling of the marine
conductor or riser upwardly of the well can be effected and the
floating vessel can be assured of being able to disconnect from the
wellhead even under emmergency conditions when the vessel may be
positioned laterally offset of the well with the associated
conductor or conduits running at an angle to the vertical between
such vessel and wellhead.
It is a further object of the present invention to disclose a
method and apparatus as in the foregoing object wherein the
coupling separator apparatus includes means and provision for
positively disconnecting or uncoupling any associated hydraulic
line couplings mounted in association with the conduit or conductor
coupling prior to drawing the conductor or conduit away from the
wellhead apparatus.
Generally stated, the method and apparatus for separating subsea
well conduit couplings, according to the present invention,
includes the provision of coupling separator means associated with
the separable coupling members for moving such members axially away
from one another in an uncoupling direction upon actuation thereof
and actuating means operable from a floating vessel above the
subsea well and coupling for actuating such coupling separator
means from such remote location. It is contemplated within the
present invention that such coupling separator means includes a
plurality of hydraulically actuated drive means, each having at
least two relatively movable parts thereof that are driven relative
to one another by introduction of hydraulic fluid under pressure
into the drive means. The actuating means associated therewith
includes hydraulic fluid line means run from the vessel to the
individual drive means for introducing hydraulic fluid under
pressure from the vessel when it is desired to positively separate
the coupling members.
More particularly, the plurality of hydraulic drive means each
include a piston, piston rod and cylinder with means for mounting
each such drive means to one of the coupling members. Means,
including an annular drive ring in the preferred exemplary
embodiment, are also associated with each of the hydraulic drive
means and are movable in response to actuation of such drive means
to engage and forcibly push the other of said coupling members
axially away from the first noted coupling member to uncouple the
same.
The present invention also contemplates the provision of additional
hydraulic drive means associated with one of the coupling members
and with portions of a plurality of associated hydraulic line
coupling members for separating or uncoupling such line couplings
upon actuation of such additional hydraulic drive means. The
release of the hydraulic line couplings is preferably accomplished
according to the present invention prior to actuating the main
hydraulic drive means to uncouple the conductor or conduit coupling
members.
A more complete understanding of the methods and apparatus of the
present invention will be attained by those skilled in the art and
various additional objects and advantages of the methods and
apparatus of the present invention will become apparent to those
skilled in the art from a consideration of the following detailed
explanation of a preferred exemplary embodiment of an apparatus for
separating subsea well conduit couplings, including marine or
conduit couplings, hydraulic line couplings and the like. Reference
will be made to the appended sheets of drawings in which the
various elements of the preferred exemplary apparatus will be
referred to by the same numerals throughout the various
figures.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is an elevational view depicting a floating platform or
vessel over a subsea well site or formation with an apparatus for
separating subsea conduit couplings according to the present
invention incorporated in the otherwise conventional drilling
hook-up apparatus as the well for separating the conduit coupling
particularly under conditions where the vessel is not directly over
the well as illustrated;
FIG. 2 is an enlarged view of the apparatus for separating subsea
conduit couplings according to the present invention and the
drilling hook-up apparatus of FIG. 1;
FIG. 3 is a plan view, partially in section, of the apparatus of
FIG. 2 taken therein along the plane III--III;
FIG. 4 is a sectional view of the apparatus of FIG. 3 taken therein
along the plane IV--IV showing the associated couplings in coupled
condition;
FIG. 5 is a detailed view of the apparatus of FIG. 4 showing the
hydraulic control line coupling portions separated by means of the
apparatus for separating conduit couplings according to the present
invention;
FIG. 6 is a detailed view of the apparatus of FIG. 4 showing the
apparatus for separating subsea conduit couplings, in accordance
with the present invention, in an initially actuated position
preparatory to moving the main conduit coupling members axially
away from each other in an uncoupling direction; and
FIG. 7 is a detailed view of the apparatus of FIGS. 4 and 6 showing
the main conduit coupling members separated by means of the
apparatus for separating subsea conduit couplings in accordance
with the present invention.
Referring first to FIG. 1, a floating vessel or platform, such as
the ship indicated generally at 10, is shown floating on a body of
water or sea 11 generally above, but offset of, a subsea well
indicated generally at 12. The vessel or ship 10 is provided with a
conventional drilling rig, indicated generally at 13, positioned
over a cellar or slot through the center of the vessel provided in
known manner. A generally conventional wellhead apparatus for
drilling is illustrated generally at 14 with an exemplary
embodiment of the subsea well conduit coupling separator apparatus,
indicated generally at 24 in FIG. 2, provided therewith.
In normal drilling operations, a marine conductor or riser 15 is
connected between the floating vessel and the wellhead apparatus by
a marine conductor coupling. One such conductor coupling suitable
for use with the apparatus of the present invention is disclosed in
my prior U.S. Pat. No. 3,333,870. The release of such coupling is
normally effected by relieving hydraulic pressure on the associated
latching means and pulling the conduit or riser 15 vertically
upwardly, causing a camming of associated locking dogs out of the
lower member of the coupling associated with the wellhead
equipment, and a separation of the upper and lower coupling
members. Such separation is easily effected when vessel 10 is
generally vertically directly above the well and riser or conduit
15 is in a generally vertical orientation as shown in dotted line
in FIG. 1. However, when vessel or platform 10 rides off to the
side of the well, as seen in FIG. 1, it frequently becomes
difficult if not impossible to pull the coupling apart because of
the binding thereof when the pulling force of conduit or riser 15
is at an angle to the axis of the coupling. As is particularly
contemplated within the present invention, apparatus for positively
separating the couplings is provided at the subsea well conduit
coupling which is actuated by hydraulic line means, as lines 16 and
17, prior to pulling the conduit or riser 15 upwardly, as will be
explained more fully hereinafter.
Referring to FIG. 2, the wellhead drilling apparatus is shown with
a drill string 18 run therethrough for purposes of drilling a well
beneath the template or table 19 upon which the wellhead casing 20
is mounted. Casing 20 may be provided with a plurality of rams 21,
22 and 23 for use in conventional drilling operations, each of
which is hydraulically operated by means of associated hydraulic
control lines described hereinafter. It is contemplated that line
means 16 and 17 illustrated in FIG. 1 may each include a plurality
of hydraulic hoses or lines bundled together to provide whatever
number of hydraulic lines may be necessary for operating the
various wellhead control devices and the hydraulic means employed
in the apparatus of the present invention.
Still referring to FIG. 2, the marine conductor coupling for
coupling conduit or riser 15 to wellhead casing 20 includes a lower
body portion 25 mounted on casing 20 and an upper body portion 26
connected to riser or conduit 15. As seen in FIGS. 2, 3 and 4, the
lower marine conductor coupling body 25 is provided with a flange
27 while the upper coupling body 26 is provided with a flange 28.
The coupling members 25 and 26 separate along a line or plane lying
between flanges 27 and 28. The associated hydraulic control lines
for operating the various wellhead controlled devices, such as rams
21, 22 and 23, are provided with connectors suitable for coupling
and uncoupling between flanges 27 and 28. As is also contemplated
within the apparatus of the present invention, means are provided
as hereinafter more fully explained for positively separating the
hydraulic control line couplings, such as coupling 30 joining
hydraulic lines 29 and 31 in FIG. 2, preparatory to uncoupling the
main marine conductor coupling members 25 and 26.
As will be described more fully in detail subsequently herein, the
exemplary apparatus of separator means for uncoupling the main
conduit coupling members 25 and 26 includes a plurality of
hydraulically actuated piston and cylinder means 32, 33 and 34, as
best seen in FIGS. 2 and 3, with the piston rod members thereof
fixedly secured to flange 35 provided on upper coupling member 26.
In the exemplary embodiment of separator means for separating the
hydraulic control line couplings 30, a plurality of hydraulic
cylinder and piston means 36, 37 and 38 are employed, as seen in
FIGS. 2 and 3, and as more fully explained hereinafter. It is
contemplated within the present invention that by selective
actuation of the hydraulic piston and cylinder means noted herein,
that the hydraulic line couplings 30 may be first disconnected and
the main marine conductor coupling members 25 and 26 thereafter
disconnected prior to pulling the casing or riser 15 upwardly
toward the vessel for releasing it from the wellhead apparatus.
Since the exemplary embodiment of conduit coupling separator
apparatus of the present invention is disclosed herein with an
exemplary form of marine conductor coupling, the marine conductor
coupling and its associated latching mechanism will now be
described in detail prior to completing the detailed description of
the apparatus of the present invention. While the marine conductor
coupling illustrated is more fully disclosed in my prior U.S. Pat.
No. 3,333,870, and reference is made thereto for the operation of
such coupling, an explanation thereof will be made here to
facilitate the further explanation and understanding of the
apparatus of the present invention.
Referring to FIG. 4, the lower marine conductor coupling member 25
is provided with an upstanding gib means or male coupling member 40
which has a pair of spaced circumferential notches 41 and 42 having
inwardly convergent inclined side walls. Gib means or coupling
member 40 is thereby adapted to be received within a socket portion
provided in association with the upper coupling member 26 and
latched therein as will now be explained.
Again referring to FIG. 4, the upper member 26 of the marine
conductor coupling in the exemplary embodiment includes a central
ring portion 43 and a lower body or socket portion 44 secured to
the riser or marine conductor or conduit 15 by means of
conventional bolts 47. Surrounding housing portions, including the
upper housing portion 45 and the lower housing portion 46 are
secured, as by welding, or other conventional means to the ring
member 43. An elastic type seal 48 is provided within the socket
member 44 to seal against the outside surface of the end of gib
means 40 while the metal seal ring 49 is provided for sealing at
the end of gib means 40 about an inner chamfered surface thereof,
as more fully explained in my U.S. Pat. No. 3,333,870.
Latching means are provided in the exemplary embodiment of marine
conductor coupling including a plurality of horizontally slidable
or movable latch elements or dogs, such as dog 50 illustrated in
FIG. 4. Each of the plurality of dogs 50 is adapted to be wedged or
forced into latching engagement with the associated gib means by
downward movement of the associated wedge or force transmitting
ring 51. Conventional hydraulic piston and cylinder means, such as
cylinder 52 are provided within the housing 45 and mounted on ring
43 with the piston rod 53 extending down within housing 46 into
engagement with the ring 51, the threaded end of rod 53 being held
thereto by a conventional nut 54. Hydraulic fluid pressure lines 55
and 56 are connected to cylinder 52, and supplied with hydraulic
fluid via the bundle of hydraulic hoses 16 or 17 for actuating the
enclosed piston upwardly or downwardly therein to selectively
either wedge dogs 50 into engagement with gib means 40, as seen in
FIG. 4, or release them as seen in FIG. 6. As seen in FIG. 6, when
dogs 50 have been released by the wedging or force transmitting
ring 51, they are moved out of locking engagement with gib means 40
due to a camming action applied thereon between the inclined mating
surfaces of the dog and notches 41 and 42 when the conduit 15 and
associated upper coupling member, including housings 45 and 46,
ring 43, socket 44 and associated parts, are pulled upwardly toward
the vessel. However, if the pull on conduit 15 and the associated
upper coupling member is not generally vertically straight
upwardly, but is in a direction inclined to the axis of the gib
means 40, a binding of the coupling members has been found to
exist, the dogs 50 do not release and the coupling members 25 and
26 cannot be released.
Means are provided, in accordance with the present invention, for
positively moving or forcing the coupling members 25 and 26 away
from each other in coaxial but opposite directions to cam latching
dogs 50 out of engagement with gib means 40 and effect a release of
the coupling members 25 and 26 preparatory to pulling conduit or
riser 15 and the upper coupling member 26 away from the well and
thus release vessel 10 from the subsea well. As is contemplated
within the present invention, such means may include a plurality of
hydraulic drive means, each including a piston, piston rod and
cylinder for driving the associated piston rod relative to the
associated cylinder upon introduction of hydraulic fluid under
pressure therein, means for mounting each of such drive means to
one of the coupling members, means for introducing hydraulic fluid
from the vessel 10 into each of such drive means for driving the
associated pistons rods relative to the associated cylinders and
means associated with each of the drive means for moving the other
coupling members in an uncoupling direction coaxially away from the
first coupling member in response to relative movement between the
cylinder and associated piston rods. Such method of disconnecting
couplings and apparatus may be employed within the present
invention for uncoupling either a main conduit coupling, such as
coupling members 25 and 26 or such a main coupling and a plurality
of hydraulic fluid control line couplings associated therewith as
well. A preferred exemplary embodiment of such coupling separator
apparatus will now be explained.
Conduit coupling separator apparatus, in the exemplary embodiment,
include the plurality of hydraulic cylinder and piston means 32, 33
and 34 and are in part illustrated generally at 60 in FIGS. 4, 6
and 7. Referring to FIGS. 4, 6 and 7, the construction of one of
the plurality of hydraulic cylinder and piston means, hydraulic
cylinder 33, will be explained, it being understood that the other
exemplary cylinders 32 and 34 are similarly constructed and
operated in association with the common members to be described. As
seen in FIG. 4, cylinder 33 is provided with a piston and piston
rod in conventional manner with a rod end fitting 61 pivotally
mounted by pin 62 to the flange 35 provided on lower housing member
46. Pin 62 is mounted in a slot 63 formed in flange 35. The
hydraulic cylinder and associated piston and piston rod means are
thereby fixed to the upper coupling member 26 so that upon
actuation thereof the cylinder 33 of each such hydraulic drive
means will move downwardly relative to the upper coupling member
26. As seen in FIG. 4, each cylinder, as cylinder 33, passes
through a port or opening 28' in flange 28 and has a cylinder base
flange 64 secured, either by being integral with or being welded
to, a drive ring or annular member 65 mounted about and coaxially
of the housing 46 and socket member 44 of upper coupling member 26.
Ring or annular member 46 thus serves as a guide for directing each
of the cylinder portions 32, 33, and 34 downwardly about coupling
member 26 into uncoupling engagement with the lower coupling member
25, or as in the preferred exemplary embodiment, also acts as a
drive ring with its lower surface 67 engaging the upper surface 68
of lower coupling member 25. Suitable hydraulic lines, as hydraulic
line 66, connected to the hydraulic line bundles 16 or 17 run from
the vessel 10 are provided for introducing hydraulic fluid under
pressure into the respective hydraulic cylinders 32, 33 and 34 to
selectively force drive ring or annular member 65 downwardly from
the inactive position of FIG. 4 into the initially actuated lower
coupling member contacting position of FIG. 6 and the coupling
separator position of FIG. 7. Annular member or ring 65 is provided
with a slide block 69' positioned in spline 69 formed in the outer
surface of housing 46 to prevent relative rotation therebetween
while allowing coaxial linear movement therebetween.
As can be seen from a comparison of FIGS. 6 and 7, the actuation of
hydraulic piston and cylinder means 32, 33 and 34 causes the
coupling members 25 and 26 to move in opposite, but coaxial,
directions to cam the locking dogs 50 out of gib means 40 and
separate and uncouple the coupling members without any binding or
twisting of the coupling members. When the coupling members 25 and
26 are separated into the uncoupled position of FIG. 7, the conduit
15 and associated hydraulic lines 16 and 17 may be pulled upwardly
away from the well releasing the vessel from the wellhead. Where
hydraulic control lines for operating devices at the portion of the
wellhead remaining at the subsea location are not included, it can
be seen that the hydraulic lines associated with the latching means
hydraulic cylinders, as cylinder 52 and the hydraulic drive means
of the apparatus of the present invention, including cylinders 32,
33 and 34, are all released and readily drawn upwardly away from
the wellhead casing and associated lower coupling member 25 when
the couplings have been released into the uncoupled position of
FIG. 7.
It is also contemplated within the present invention that in
certain subsea well installations, a plurality of hydraulic fluid
control lines, as lines 29, 31, may also be provided for
controlling various devices associated with the wellhead apparatus
or equipment below the marine conductor coupling. In such
installations, it is considered desirable to be able to release the
associated hydraulic line connectors 30 prior to releasing the main
marine conductor coupling members 25 and 26. The method and
apparatus of the present invention allows such prereleasing of the
hydraulic line couplings prior to the positive separation of the
coupling members 25 and 26 as will now be explained in detail.
Conduit coupling separator apparatus for uncoupling hydraulic fluid
line couplings 30, in the exemplary embodiment, includes the
plurality of hydraulic drive means, including hydraulic cylinder
means 36, 37 and 38, and is in part illustrated at 70 in FIGS. 4
and 5. As seen in FIGS. 2 and 3, a plurality of hydraulic drive
means are employed in the apparatus of the present invention for
disconnecting the hydraulic line couplings. The exemplary hydraulic
cylinder means 38, as seen in FIGS. 4 and 5, will be explained in
detail, it being understood that the other hydraulic means 36 and
37 are of similar construction and operate in cooperation with
cylinder 38 and the commonly associated members for releasing the
couplings 30 as explained herein. Referring to FIGS. 4, hydraulic
cylinder means 38 includes a piston and piston rod 71 of
conventional nature with a rod end fitting 72 mounted by pin 73 to
a bracket or flange 74 mounted on the exterior surface of annular
member or ring 65. Each hydraulic cylinder, as cylinder 38, is
provided with a base flange, as flange 75, bolted as shown, or
otherwise secured, to flange 28 which in turn is formed integrally
with a second drive or guide ring 76 mounted coaxially about and
slidable relative to the annular member 65. Annular member 65 is
provided with a spline 77 on its outer surface in which slide block
78, fixed to ring 76, is slidable for limiting guide ring 76 and
integral flange 28 to vertical coaxial movement relative to the
annular member 65, inner housing 46, inner socket member 44 and,
when the coupling members are in coupled condition as shown in FIG.
4, the gib means 40. As seen in FIG. 4, each of the hydraulic
cylinders 36, 37 and 38 has its associated internal piston at the
upper end of the associated cylinder when the apparatus is in the
coupled condition of FIG. 4. The associated hydraulic lines, as
line 79, are connected to the upper end of each cylinder so that
upon introduction of hydraulic fluid into each of the cylinders,
the cylinders, guide ring 76 and associated flange 28 will all be
drawn straight vertically upwardly in a direction coaxial to the
center line of the coupling members 25 and 26. By providing the
hydraulic line coupling body portions 80 on the lower flange 27, in
the exemplary coupling 30' in FIG. 4, with the center line thereof
parallel to the center line of the main coupling members 25 and 26,
the aforedescribed raising of flange 28 draws the male line
coupling portion 82 directly out of the associated socket portion
80 and its associated internal seal 81, as seen in FIG. 5. The male
portion 82 of each hydraulic line coupling 30, 30' is preferably
connected by a fitting portion 83 to the movable flange 28 and
integral guide ring portion 76 so that upon actuation of the
hydraulic cylinder means 36, 37 and 38, all of the associated upper
hydraulic line portions 29, 29' are coupled from the lower
hydraulic line portions 31, 31'.
According to the preferred method of releasing subsea well conduit
couplings of the present invention, the hydraulic drive means
including cylinders 36, 37 and 38 are initially operated to
uncouple the line couplings 30, as seen in FIGS. 4 and 5, prior to
releasing the main coupling members 25 and 26. The hydraulic means
in the coupling latching apparatus, including cylinder 52, as seen
in FIG. 6, may then be operated to a release position so that the
associated latching dogs 50 are released and ready to be cammed
outwardly of the associated gib means notches 41 and 42 upon
actuation of the main hydraulic drive means including cylinders 32,
33, and 34. The extent of travel of flange 28 during the release of
line couplings 30 as seen in FIGS. 4 and 5 is sufficiently great so
that upon the initial downward movement of annular means 65, and
thus the associated brackets 74 mounting the cylinders 36, 37 and
38, a recoupling of line coupling portions 80 and 82 is not
effected, such initial actuating position for annular member 65
being illustrated in FIG. 6. Thereafter, continued actuation of the
hydraulic drive means including cylinders 32, 33 and 34 causes
further separation of such line couplings and a separation or
uncoupling of the main coupling members as seen in FIG. 7.
From the foregoing detailed explanation of a preferred exemplary
embodiment of the method and apparatus for separating subsea
conduit couplings, according to the present invention, the method
and apparatus of the present invention provide for a positive
uncoupling or separation of subsea couplings, including marine
conductor couplings, hydraulic line couplings or other subsea
conduit couplings, to positively release a floating vessel from a
subsea well even where the vessel has floated to an offset position
from that directly over the well and a binding non-releasable
condition would otherwise exist. It should be understood by those
skilled in the art that various modifications, adaptations and
alternative embodiments of the method and apparatus of the present
invention may be made within the scope of the present invention
which is defined in the following claims.
* * * * *