U.S. patent number 3,766,978 [Application Number 05/060,964] was granted by the patent office on 1973-10-23 for remote controlled oil well pipe shear and shut-off apparatus.
This patent grant is currently assigned to Shaffer Tool Works. Invention is credited to Edward T. Cugini, Valdek J. Orund.
United States Patent |
3,766,978 |
Orund , et al. |
October 23, 1973 |
REMOTE CONTROLLED OIL WELL PIPE SHEAR AND SHUT-OFF APPARATUS
Abstract
In an offshore oil well production system including a surface
platform, a submerged wellhead, and a pipe string interconnecting
the wellhead and platform, the provision of a pipe shear and
shut-off apparatus between the platform and wellhead having a
housing with a through-bore with an enlarged intermediate chamber
and end bores for receiving a section of the pipe and means within
the apparatus for shearing the pipe and closing the fluid passage
through the apparatus when the pipe is severed, means for selective
actuation of the apparatus and remote control means for the
actuating means which is operative at a remote location from the
wellhead notwithstanding the loss of physical connection between
the platform and wellhead through the pipe string, such as when the
pipe string is ruptured.
Inventors: |
Orund; Valdek J. (Anaheim,
CA), Cugini; Edward T. (Brea, CA) |
Assignee: |
Shaffer Tool Works (Brea,
CA)
|
Family
ID: |
26740573 |
Appl.
No.: |
05/060,964 |
Filed: |
July 2, 1970 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
Issue Date |
|
|
806516 |
Mar 12, 1969 |
3590920 |
Jul 6, 1971 |
|
|
Current U.S.
Class: |
166/361; 166/55;
166/363 |
Current CPC
Class: |
E21B
29/12 (20130101); E21B 34/04 (20130101); E21B
29/08 (20130101) |
Current International
Class: |
E21B
29/08 (20060101); E21B 29/00 (20060101); E21B
34/04 (20060101); E21B 29/12 (20060101); E21B
34/00 (20060101); E21b 029/00 () |
Field of
Search: |
;166/.5,.6,.55,53,55.2,72 ;175/7 |
References Cited
[Referenced By]
U.S. Patent Documents
Foreign Patent Documents
Primary Examiner: Champion; Marvin A.
Assistant Examiner: Favreau; Richard E.
Parent Case Text
This is a division of application Ser. No. 806,516 filed Mar. 12,
1969, now U.S. Pat. 3,590,920 issued July 6, 1971.
Claims
We claim:
1. In an offshore oil well production system, comprising a surface
platform, an undersea wellhead, and a pipe string connected to the
wellhead and the platform, the provision of:
a submerged pipe shear and shut-off apparatus between said platform
and said wellhead including, a housing having a through-bore with
an enlarged intermediate chamber and end bores for receiving the
pipe, means within said chamber for shearing said pipe, closing
means within said chamber for preventing fluid passage through said
housing after said pipe is severed;
said sumbmerged pipe shear and shut-off apparatus shearing means
including slidably mounted blade means for movement transverse to
said pipe to effect cut-off and said closing means includes a
shut-off plug slidably mounted for movement transverse to said pipe
to an operative position, said apparatus additionally including
means urging said shut-off plug into sealing relation with said
housing through-bore;
means for selective actuation of said apparatus; and
remote control means for said actuating means operative at a remote
location from said wellhead.
Description
The present invention relates to an apparatus for use in connection
with oil well offshore production systems wherein a surface
platform is stationed with respect to a wellhead and is
interconnected with the wellhead through at least one pipe string.
Generally, the platform or floating vessel is maintained in its
relative position to the wellhead by suitably securing the floating
vessel to the floor of the ocean or sea through mooring lines.
In the above-described system, as well as in various other types of
offshore oil well production systems, there may be provided an
apparatus for shearing the pipe string and shutting off the fluid
passage in the event of rupture of the pipe string so as to prevent
blowout of the well. In operation, it is necessary to actuate such
apparatus so as to perform the shearing and shut-off functions.
Such operation may be manual, such as by sending down a diver, but
the disadvantages of such operation are apparent. In the prior art,
the operation of shear and shut-off apparatus has been controlled
from the surface platform. However, the defect in such prior art
systems is that if the surface platform moves relative to the
wellhead so as to rupture the pipe string, it will also likely
rupture any other physical means interconnecting the platform and
the apparatus to be controlled. For example, if the anchor lines of
the surface platform are severed by another vessel, or break
because of heavy seas, there is no longer any physical connection
between the surface platform and the apparatus.
In the pipe shear and shut-off apparatus known to the prior art,
there is also the difficulty of reliably assuring that the fluid
flow passage will be completely shut off because of the possibility
that the pipe will not be properly severed. In other words, in some
prior art apparatus, the shearing means may result in crushing or
deforming of the pipe which would interfere with the effective
shut-off of the flow passage.
Accordingly, it is a general object of the present invention to
provide a remote controlled oil well pipe shear and shut-off
apparatus that avoids all of the foregoing disadvantages of similar
types of apparatus and offshore oil well production systems used
heretofore.
It is another object of the present invention to provide an
offshore oil well production system including a surface platform, a
submerged wellhead, an interconnecting pipe string, a submerged
pipe shear and shut-off apparatus, with means for remotely
controlling the actuation of the apparatus so that the fluid flow
passage may be shut off in the event of pipe string rupture and
movement of the platform relative to the wellhead.
It is still another object of the present invention to provide an
offshore oil well production system of the above-described type,
wherein the remote control means may include signal transmitting
and receiving apparatus carried by the platform and the pipe shear
and shut-off apparatus for selective operation by an operator
aboard the platform.
It is yet another object of the present invention to provide an
offshore oil well production system of the above-described type
wherein the remote control means may include fixed length means
physically interconnecting the platform and wellhead when the
platform is in a preselected location relative to the wellhead
which is ruptured when the platform is moved from such preselected
location so as to automatically actuate the pipe shear and shut-off
apparatus.
One more object of the present invention is to provide a submerged
pipe shear and shut-off apparatus wherein a pipe string may be
simultaneously sheared and shut off and wherein the shut-off means
is maintained in sealing relation to prevent fluid passage
flow.
It is yet one more object of the present invention to provide an
apparatus of the last-described type wherein the seal is maintained
without physical contact between a surface platform and the
wellhead which was interconnected by the pipe string prior to
rupture.
Other objects and advantages of this invention will be readily
apparent from the following description when considered in
connection with the appended drawings.
IN THE DRAWINGS
FIG. 1 is a schematic view of an exemplary offshore oil well
production system including the present invention;
FIG. 2 is a detailed view of the apparatus shown in FIG. 1
illustrating components of the system schematically;
FIG. 3 is a detailed view as in FIG. 2 showing alternate components
for use in the system;
FIG. 4 is a side sectional view of the apparatus shown in FIGS. 2
and 3;
FIG. 5 is a side sectional view as in FIG. 4 showing apparatus in
shut-off position;
FIG. 6 is a sectional view taken along the plane VI--VI of FIG.
4;
FIG. 7 is a sectional view taken along the plane VII--VII of FIG.
4;
FIG. 8 is a sectional view taken along the plane VIII--VIII of FIG.
4; and
FIG. 9 is a sectional view taken along the plane IX--IX of FIG.
5.
Referring now to FIGS. 1 through 3, there is shown in FIG. 1 an
offshore oil well production system generally comprising a surface
platform or vessel 20, a wellhead indicated generally at 21, and a
production line or pipe string generally indicated at 22. The
platform 20 may be fixed or supported by the floor of the body of
water, or may be a floating vessel such as that illustrated at 20.
The wellhead 21 is submerged or undersea and is mounted to the
floor of the sea in a manner well known in the art. While a
plurality of production lines or pipe strings may interconnect the
wellhead and surface platform, there is shown for purposes of
illustration a single pipe string 22 comprising a plurality of pipe
sections which may extend generally vertically from the wellhead to
the platform.
The platform 20 may be secured in its relation or position to the
wellhead by means of anchor lines 23 which may be connected to a
sub-surface buoy 24 connected through a cable 25 to an anchor 26 on
the ocean floor. Obviously, other means for maintaining the
floating platform 20 in relation to the wellhead 21 may be provided
as are well known in the art.
In the present invention, the offshore oil well production system
is also provided with a submerged pipe shear and shut-off apparatus
generally indicated at 30, means for selective actuation of the
apparatus indicated generally at 80, and remote control means
generally indicated at 110. The pipe shear and shut-off apparatus
is submerged and may be mounted adjacent the wellhead between the
platform and the wellhead. The means 80 for selective actuation of
the apparatus may be carried by such apparatus as in the exemplary
embodiment.
Remote control means, indicated generally at 110, in the exemplary
embodiment illustrated in FIG. 2, may comprise a signal
transmitting means 111, such as a radio transmitter, carried by
floating platform 20. The remote control means also includes signal
receiving means 112, as seen in FIG. 2, carried by means 80 for
selective actuation of pipe shear and shut-off apparatus 30. There
is shown a second exemplary embodiment of means for remote control
of the apparatus actuating means which comprises a fixed length
physical means such as a fluid pressure line 115 in operative
communication with the means 80 when the pipe string 22 is
intact.
In operation, each of the above-described remote control means
automatically renders the actuating means operative, or maintains
operative connection between the apparatus and surface platform,
upon movement of the platform from its preselected position
relative to the wellhead. In the first embodiment, rupture of the
pipe string 22 which could occur when platform 20 has broken away
from its anchor line 23, severs all physical connection between the
platform 20 and the pipe shear and shut-off apparatus 30. However,
an operator aboard floating vessel 20 may manually transmit a
signal from transmitting means 111 to signal receiving means 112 so
as to render actuating means 80 operative thereby shearing pipe
string 22 and providing fluid flow shut-off. In the second
embodiment, movement of the surface platform 20 so as to rupture
pipe string 22 will simultaneously cause rupture of fixed length
fluid pressure line 115 opening such line to ambient pressure which
will render the actuating means operative so as to shear and shut
off pipe string 22.
The submerged pipe shear and shut-off apparatus 30 of the present
invention generally comprises a housing 32, carrier means indicated
generally at 40, pipe shearing means indicated generally at 50,
closing means indicated generally at 60, means axially urging a
shut-off plug into sealing relation indicated generally at 65, and
the actuating means indicated generally at 80.
Referring now to FIGS. 4 through 9, there is shown an exemplary
embodiment of a pipe shear and shut-off apparatus in accordance
with the present invention wherein the housing 32 includes a
through-bore 33 which defines a work chamber 34 and top and bottom
end bores 35, 36 respectively. Chamber 34 is intermediate the end
bores 35, 36 and is enlarged and disposed laterally of the
longitudinal axis of the pipe passing through housing 32 and
indicated at P. Pipe P comprises a first pipe section P1 connected
to the platform 20 and a second pipe section P2 connected to the
wellhead 21. The intermediate enlarged chamber 34 may also include
a second laterally disposed portion indicated at 34a for receiving
the cutting blade and any portions of the pipe which may be crushed
after the shearing operation is complete.
Carrier means 40 is slidably mounted for movement transverse to the
axis of pipe P and is normally disposed in a zone to one side of
the axis of pipe P. In the exemplary embodiment, such carrier means
may comprise carrier member 41 having a downwardly directed opening
42 for receiving the actuating rod of the actuating means described
hereinafter. Carrier member 41 has a generally cylindrical opening
43 for receiving a shut-off plug and has parallel sidewalls 44, 45
as seen best in FIG. 9. The carrier member 41 is slidably supported
on longitudinally extending tracks 46, 47 disposed transversely to
the axis of pipe P and within chamber 34 and preferably integral
with housing 32, as seen in FIG. 9 Housing 32 also includes
guideways 37, 38 integral with the vertical walls adjacent the
tracks 46, 47 respectively, and extending longitudinally parallel
with the tracks on opposite sides of carrier member 41 and in
sliding engagement with carrier member sidewalls 44, 45 to guide
transverse movement of the carrier member.
The pipe shear and shut-off apparatus 30 also includes pipe
shearing means indicated generally at 50 which comprises blade
means 51 and anvil means 55. Blade means 51, in the exemplary
embodiment, is carried by carrier member 41 for movement transverse
to pipe P. The blade means comprises a blade or cutting edge 52
fixedly mounted on the forward end of carrier member 41 with
fasteners 53. The cutting edge 52 has a width greater than the
diameter of pipe P and has an upper edge in the same horizontal
plane as the upper surface of the carrier member 41, as seen in
FIGS. 4 and 5. In the preferred embodiment, the cutting edge 52 is
straight and is angularly oriented with respect to the direction of
movement.
The anvil means in the exemplary embodiment is fixedly mounted in
the housing 32 and comprises an annular member 56 of hardened steel
retained in the housing at the upper surface of the chamber by
studs 57. Annular anvil member 56 is mounted at the periphery of
through-bore portion 35 and is sealed within the chamber housing by
means of annular sealing ring 58. The lower plane of anvil member
56 is coplanar with the upper plane of carrier member 41 and
cutting edge 52 so as to define a shear plane.
The pipe shear and shut-off apparatus 30 also includes closing
means 60 for preventing fluid passage through housing 32 when pipe
P has been severed. In the exemplary embodiment, such closing means
comprises a shut-off plug 61 carried by carrier member 41 in
opening 43 for transverse movement into an operative position (as
seen in FIG. 5) axially aligned with through-bore 33. Shut-off plug
61 comprises a substantially cylindrical, solid, metallic body 62
having an axis sustantially parallel to the axis of pipe P. The
shut-off plug 61 carries an annular sealing member 63 on the
peripheral edge of the upper surface for sealing engagement with
anvil member 56 when the shut-off plug is in the operative
position.
Means 65 for axially urging the shut-off plug 61 is provided in
apparatus 30 and in the exemplary embodiment comprises ramp or cam
means 66 carried by housing 32 in the path of carrier member 41.
Ramp means 66 includes a pair of ramp members 67, 68 positioned on
opposite sides of through-bore 35 within chamber 34 and integral
with tracks 46, 47, as seen best in FIG. 9. The means for axially
urging the shut-off plug into sealing relation with the anvil
member 56 mounted in housing 32 also includes ramp surfaces 69, 70
on the lower side of shut-off plug body 62 defined by cut-out
portions thereof. The ramp surfaces 69, 70 have the same slope and
are complementary with the ramp members 67, 68. Preferably, the
ramp members and ramp surfaces have a slope so as to provide
substantial friction through the metal-to-metal contact thereof so
as to maintain the shut-off plug and anvil member in sealing
relation.
The pipe shear and shut-off apparatus 30 includes actuating means
80 which in the exemplary embodiment comprises an actuator housing
81 defining a cylindrical chamber 82 open at one end and sealed by
an end plate 83 through a plurality of fasteners 84. The opposite
end of housing 81 is secured through studs and nuts 85 to the end
of housing 32 of the apparatus. The engaging wall 86 of actuator
housing 81 is provided with an opening 87 for receiving the
actuator member 88 of a piston 89 slidably mounted in chamber 82.
Piston 89 carries annular sealing members 90 while end wall 86 of
housing 81 carries sealing members 91 for sealing engagement with
actuator rod 88. The actuating means also comprises a high pressure
fluid source 92 as seen in FIGS. 2 and 3, in fluid communication
with piston chamber 82 through a conduit 93, valve 94, and conduits
95, 96.
In the embodiment illustrated in FIG. 2, the valve 94 may be a
simple single gate valve controlled by signal receiving means 112
so as to allow the high pressure gas to flow from source 92 through
the valve through conduit 95 thereby moving piston 89 and carrier
member 41 to the right, as viewed in FIGS. 4 and 5. Conduit 96 is
provided for relief and for returning the carrier means to the
inoperative position after the shear and shut-off apparatus has
been used. In the embodiment illustrated in FIG. 3, the valve 94 is
actuated by rupture of the fluid pressure line 115 opening such
line to ambient pressure so that the high pressure gas source may
open the gate allowing the high pressure gas to pass through
conduit 95 and to move piston 89 as previously described.
In operation, when the carrier means is moved transverse to the
pipe, the blade or cutting edge 52 severs the pipe P into portions
P.sub.1 and P.sub.2. Simultaneously the shut-off plug 61 is moved
into axial alignment with the through-bore 33 and pipe sections
P.sub.1 and P.sub.2 and is axially urged through ramp members 67,
68 and ramp surfaces 69, 70 into sealing relation with anvil member
56 so as to prevent fluid flow through the apparatus thereby
preventing blow-out of the well. The shut-off plug is maintained in
the sealing relation by virtue of the low slope and high friction
between the ramp members and ramp surfaces which maintains the
shut-off plug and anvil member in contact. Moreover, it is an
important feature of this invention that the shut-off plug is
maintained in sealing relation by the differential in pressure
across the shut-off plug. Specifically, if pipe section P.sub.2 is
connected to the wellhead whereas pipe P.sub.1 is connected to the
platform and is the pipe that will be ruptured, the pressure acting
on the underside of the shut-off plug will be the well pressure
whereas the pressure acting on the upper surface will be ambient
pressure. This difference in pressure will tend to maintain the
shut-off plug in sealing relation with anvil member.
It is also to be understood that the drill string pipe section
connections are not easily severable by the apparatus of the
present invention, and it is therefore comtemplated that a pair of
such apparatus may be employed in spaced relation such that one of
such apparatus will necessarily be positioned on a non-connection
portion of the drill string.
It will now be seen that all of the above-mentioned objects are
accomplished by the invention and the preferred embodiment
described and illustrated herein. Other modifications and
variations of the present invention are possible in light of the
above teachings and it is therefore to be understood that within
the scope of the appended claims, the invention may be practiced
otherwise than as specifically described.
* * * * *