U.S. patent number 3,590,920 [Application Number 04/806,516] was granted by the patent office on 1971-07-06 for remote-controlled oil well pipe shear and shutoff apparatus.
This patent grant is currently assigned to Shaffer Tool Works. Invention is credited to Edward T. Cugini, Valdek J. Orund.
United States Patent |
3,590,920 |
Orund , et al. |
July 6, 1971 |
REMOTE-CONTROLLED OIL WELL PIPE SHEAR AND SHUTOFF 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
shutoff apparatus between the platform and wellhead having a
housing with a throughbore 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: |
25194217 |
Appl.
No.: |
04/806,516 |
Filed: |
March 12, 1969 |
Current U.S.
Class: |
166/55; 166/361;
166/364; 166/363; 251/1.3 |
Current CPC
Class: |
E21B
29/08 (20130101); E21B 34/04 (20130101) |
Current International
Class: |
E21B
34/00 (20060101); E21B 29/00 (20060101); E21B
34/04 (20060101); E21B 29/08 (20060101); E21b
029/00 () |
Field of
Search: |
;166/.5,.6,55 |
References Cited
[Referenced By]
U.S. Patent Documents
Primary Examiner: Champion; Marvin A.
Assistant Examiner: Favreau; Richard E.
Claims
We claim:
1. A combination pipe shear and shutoff apparatus for use in well
operations to sever a pipe string and provide immediate complete
shutoff in the event of pipe string rupture, comprising:
a housing defining a work chamber and including a through bore for
receiving a pipe;
carrier means slidably mounted in said work chamber for movement
transverse to said pipe;
pipe-shearing means including blade means carried by said carrier
means to effect cutoff of said pipe;
a shutoff plug carried by said carrier means in a direction
transverse to said pipe into an operative position;
means axially urging said shutoff plug into sealing relation with
said housing through bore when in the operative position; and
actuating means for selective movement of said pipe-shearing blade
means and said shutoff plug.
2. The apparatus of claim 1 wherein said means axially urging said
shutoff plug into sealing relation with said housing through bore
comprises ramp means carried by said housing within said work
chamber in the path of slidable movement of said shutoff plug and
said plug includes complementary ramp surfaces whereby transverse
sliding movement of said plug into sealing relation with said
chamber through bore.
3. The apparatus of claim 1 wherein said actuating means comprises
an actuator housing defining a cylinder, a piston slidably mounted
in said cylinder and in operative engagement with said carrier
means, a high-pressure fluid source in fluid communication with
said piston cylinder, and valve means for selectively controlling
fluid flow to and from said piston cylinder.
4. The apparatus of claim 1 wherein said pipe-shearing means
additionally includes annular anvil means fixedly supported by said
housing and at the periphery of said through bore.
5. The apparatus of claim 1 wherein said shutoff plug, after cutoff
of said pipe, is in sealing relation with said housing through bore
portion receiving that section of the pipe extending away from a
wellhead, the other through bore portion receiving that section of
the pipe connected to the wellhead, whereby said shutoff plug
surface in sealing relation is exposed to ambient pressure when
said pipe section extending away from the wellhead is ruptured and
the opposite surface of said shutoff plug is exposed to well fluid
pressure thereby urging said shutoff plug into further sealing
relation with said housing through bore.
6. The apparatus of claim 1 wherein said shutoff plug comprises a
substantially cylindrical solid metallic body having an axis
substantially parallel to the axis of said housing through bore and
carries an annular sealing member for engagement with said annular
anvil means when said shutoff plug is in the operative
position.
7. The apparatus of claim 1 wherein said housing includes
longitudinally extending tracks disposed transversely to said pipe
and within said work chamber for slidably supporting said carrier
means, and longitudinally extending guide ways substantially
parallel to said tracks and within said chamber disposed on
opposite sides of said carrier means.
8. In a combination pipe cutoff and shutoff apparatus for use in
well operations for severing a pipe having a longitudinal axis, the
combination of:
a housing having an internal chamber disposed laterally of said
pipe axis and having a through bore extending along said axis for
receiving a portion of said pipe in said chamber;
carrier means guidably mounted within said chamber in a zone
transverse to and at one side of said axis for cutting said pipe
and sealing said through bore by movement of said carrier means in
one direction in said zone;
said carrier means including a fixed cutting edge and a shutoff
plug behind said fixed cutting edge and movable relative to said
carrier means in the axial direction of said pipe;
and actuating means for said carrier means whereby movement of said
carrier means in said one direction is adapted to cut said pipe
portion within said chamber and to immediately thereafter move said
plug to seal said through bore.
9. An apparatus as stated in claim 8 wherein said internal chamber
includes a chamber portion on the opposite side of said axis for
receiving said fixed cutting edge on said carrier means and the
crushed severed end of said pipe.
10. An apparatus as stated in claim 8 including cam means on said
housing engageable by said plug during movement of said carrier
means to move said plug into sealing relation with said through
bore.
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 shutoff 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 shutoff 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 shutoff 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
shutoff of the flow passage.
Accordingly, it is a general object of the present invention to
provide a remote-controlled oil well pipe shear and shutoff
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 shutoff 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 shutoff 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 shutoff
apparatus.
One more object of the present invention is to provide a submerged
pipe shear and shutoff apparatus wherein a pipe string may be
simultaneously sheared and shut off and wherein the shutoff 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
shutoff 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
subsurface 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 shutoff 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 shutoff apparatus is
submerged and may be mounted adjacent the wellhead between the
platform and the wellhead. The means 60 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 shutoff 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 shutoff 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 shutoff. 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 shutoff 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
shutoff 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 shutoff 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 shutoff 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 shutoff 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 shutoff 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 shutoff 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. Shutoff plug 61
comprises a substantially cylindrical, solid, metallic body 62
having an axis substantially parallel to the axis of pipe P. The
shutoff 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 shutoff plug is in the operative
position.
Means 65 for axially urging the shutoff 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 shutoff plug into sealing relation with the anvil member
56 mounted in housing 32 also includes ramp surfaces 69, 70 on the
lower side of shutoff plug body 62 defined by cutout 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 shutoff plug and anvil member in sealing relation.
The pipe shear and shutoff 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 shutoff 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 shutoff 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 blowout of the well. The shutoff 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
shutoff plug and anvil member in contact. Moreover, it is an
important feature of this invention that the shutoff plug is
maintained in sealing relation by the differential in pressure
across the shutoff 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 shutoff 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
shutoff plug in sealing relation with the 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 contemplated that a pair of
such apparatus may be employed in spaced relation such that one of
such apparatus will necessarily be positioned on a nonconnection
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.
* * * * *