Note: Descriptions are shown in the official language in which they were submitted.
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TITLE OF THE INVENTION:
Blow Out Preventer with Telescopic Conductor Tube Assembly
FIELD OF THE INVENTION
The present invention relates to a blow out preventer used to stem the flow of
fluids
from an oil or gas well.
BACKGROUND OF THE INVENTION
Movement of rams and closure doors of a blow out preventer is effected through
the
use of a hydraulic pump that pumps hydraulic fluids through hydraulic lines. A
first set of
hydraulic lines supply hydraulic fluid to move the rams between an open
position and a
closed position. A second set of hydraulic lines supply hydraulic fluid to
move the closure
door providing access for purpose of servicing and inspection between an open
position and
a closed position.
SUMMARY OF THE INVENTION
According to the present invention there is provided a blow out preventer
which
includes body having an interior cavity defining an axial flow passage and at
least one
pair of radial ram receiving passages intersecting the axial flow passage. A
ram passage
closure is provided for a remote end of each of the ram receiving passages.
Each closure has
an exterior face, an interior face, and a passage that extends between the
exterior face and
the interior face. A closure lock is provided having a locking position and a
release position.
In the locking position, the closure is locked to the body. In the release
position, the closure
is free to move relative to the body. A hydraulic cylinder is mounted on the
exterior face of
each closure. The hydraulic cylinder has an interior side wall defining an
interior cavity. A
piston is disposed within the interior cavity of the hydraulic cylinder and
divides the
hydraulic cylinder into a first chamber and a second chamber. The piston has a
first face
facing the first chamber and a second face facing the second chamber. A first
hydraulic
fluid port is adapted to permit hydraulic fluid to enter the first chamber and
exert a force
against the first face of the piston in order to cause the piston to move in a
first direction. A
second hydraulic fluid port is adapted to permit hydraulic fluid to enter the
second chamber
and exert a force against
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the second face of the piston in order to cause the piston to move in a second
direction. A ram
is disposed in the passage of the closure. The ram has a first end and a
second end. The first
end extends into one of the ram receiving passages of the body. The second end
is secured to
the piston, such that movement of the piston results in movement of the ram. A
telescopic
conductor tube assembly is provided having a dual walled first conductor tube
which
telescopically interacts with a dual walled second conductor tube. The first
conductor tube is
connected to the body and has an inner tube defining an inner passage and an
outer sleeve
defining an outer annular passage. The second conductor tube is connected to
the closure and
has an inner tube defining an inner passage and an outer sleeve defining an
outer annular
passage. Upon relative telescopic extension of the conductor tube assembly,
the closure is
carried by the second conductor tube away from the body. The conductor tube
assembly
defines a first tlow path along the inner passage of the first conductor tube
and then along the
outer annular passage of the second conductor tube to the first hydraulic
fluid port. The
conductor tube assembly also defines a second flow path along the outer
annular passage of
the first conductor tube and then along the inner passage of the second
conductor tube to the
second hydraulic fluid port. The conductor tube assembly has a first operating
mode when the
closure lock is in the locking position and a second operating mode when the
closure lock is
in the release position. In the first operating mode, when hydraulic fluid is
supplied to the
first flow path, the closure lock prevents telescopic movement of the
conductor tube assembly
and hydraulic fluid flows along the first flow path into the first hydraulic
fluid port acting
against the first face of the piston to cause the piston to move in the first
direction, with
hydraulic fluid being concurrently exhausted from the second chamber through
the second
fluid port passing along the second flow path. In the first operating mode,
when hydraulic
fluid is supplied to the second flow path, hydraulic fluid flows along the
second flow path into
the second hydraulic fluid port acting against the second face of the piston
to cause the piston
to move in the second direction, with hydraulic fluid being concurrently
exhausted from the
first chamber through the first fluid port passing along the first flow path.
In the second
operating mode, when hydraulic fluid is supplied to the first flow path,
hydraulic fluid
flowing along the first flow path telescopically moves the conductor tube
assembly carrying
the closure away from the body to an open position while concurrently
supplying hydraulic
fluid to the hydraulic cylinder. In the second operating mode, when hydraulic
fluid is
supplied to the second flow path, hydraulic fluid flowing along the second
flow path
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telescopically moves the conductor tube assembly carrying the closure toward
the body to a
closed position, while concurrently supplying hydraulic fluid to the hydraulic
cylinder.
BRIEF DESCRIPTION OF THE DRAWINGS
These and other features of the invention will become more apparent from the
following description in which reference is made to the appended drawings, the
drawings are
for the purpose of illustration only and are not intended to in any way limit
the scope of the
invention to the particular embodiment or embodiments shown, wherein:
FIG. 1 is a side elevation view of a blow out preventer constructed in
accordance with
the teachings of the present invention.
FIG. 2 is a side elevation view, in section, of the blow out preventer
illustrated in
FIG. 1 with hydraulic fluid being supplied to the second fluid path when the
conductor tube
assembly is in the first operating mode with the closure lock in the locking
position.
FIG. 3 is a side elevation view, in section, of the blow out preventer
illustrated in
FIG. 1 with hydraulic fluid being supplied to the first fluid path when the
conductor tube
assembly is in the first operating mode with the closure lock in the locking
position.
FIG. 4 is a side elevation view, in section, of the blow out preventer
illustrated in
FIG. 1 with hydraulic fluid being supplied to the first fluid path when the
conductor tube
assembly is in the first operating mode with the closure lock in the locking
position.
FIG. 5 is a side elevation view, in section, of the blow out preventer
illustrated in
FIG. 1 with hydraulic fluid being supplied to the second fluid path when the
conductor tube
assembly is in the first operating mode with the closure lock in the locking
position.
FIG. 6 is a side elevation view, in section, of the blow out preventer
illustrated in
FIG. 1 with hydraulic fluid being supplied to the first fluid path when the
conductor tube
assembly is in the second operating mode with the closure lock in the release
position.
FIG. 7 is a side elevation view, in section, of the blow out preventer
illustrated in
FIG. 1 with hydraulic fluid being supplied to the second fluid path when the
conductor tube
assembly is in the second operating mode with the closure lock in the release
position.
FIG. 8 is a first detailed side elevation view, in section, of the blow out
preventer
illustrated in FIG. 1, showing flow restrictor operation to slow opening of
closure.
FIG. 9 is a second detailed side elevation view, in section, of the blow out
preventer
illustrated in FIG. 1. showing flow restrictor operation to slow opening of
closure.
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FIG. 10 is a third detailed side elevation view, in section, of the blow out
preventer
illustrated in FIG. 1. showing flow restrictor operation to slow opening of
closure.
DETAILED DESCRIP'I'ION OF THE PREFERRED EMBODIMENT
The preferred embodiment, a blow out preventer generally identified by
reference
numeral 10, will now be described with reference to FIGS. 1 through 10.
Structure and Relationship of Parts:
Referring now to FIG. 1, there is shown blow out preventer 10, including a
body
12 having an interior cavity 14 defining an axial flow passage 16 and at least
one pair of
radial ram receiving passages 18 intersecting axial flow passage 16. There is
also a ram
passage closure 20 for a remote end 22 of each ram receiving passage 18.
Referring to FIG.
2, each ram passage closure has an exterior face 24, an interior face 26, and
a passage 28 that
extends between exterior face 24 and interior face 26. A closure lock (shown
as bolts 29) has
a locking position where closure 20 is locked to body 12, and a release
position (when bolts
29 removed) where closure 20 is free to move relative to body 12. Mounted
between exterior
face 24 and interior face 26 of each closure 20 is a hydraulic cylinder 32
that has an interior
side wall 34 defining an interior cavity 36.
Referring to FIG. 2 through 5, a piston 38 is disposed within interior cavity
36 of
hydraulic cylinder 32. Piston 38 divides interior cavity 36 of hydraulic
cylinder 32 into two
chambers depending upon the relative positioning piston 38 with interior
cavity 36. When
piston 38 is in the position illustrated in FIG. 4, a first chamber 40 is
fonned. When piston
38 is in the position illustrated in FIG. 2, a second chamber 42 is fonned.
Referring to FIG.
4, piston 38 has a first face 44 facing first chamber 40. Referring to FIG. 2,
piston 38 has a
second face 46 facing second chamber 42. Referring to FIG. 3, a first
hydraulic fluid port
48B is adapted to permit hydraulic fluid to enter first chamber 40 and exert a
force against
first face 44 of piston 38 in order to cause piston 38 to move in a first
direction, as indicated
by arrows 49. Referring to FIG. 5, a second hydraulic fluid port 50B is
adapted to permit
hydraulic fluid to enter second chamber 42 and exert a force against second
face 46 of piston
38 in order to cause piston 38 to move in a second direction, as indicated by
arrows 51. A
ram 52 that has a first end 54 and a second end 56 is disposed in passage 28
of closure 20.
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First end 54 extends into one of the ram receiving passages 18 of body 12.
Piston 38 is
secured to ram 52 toward second end 56, such that movement of piston 38
results in
movement of ram 52. Referring to FIG. 1, a ram block 55 is attached to first
end 54. Ram
block 55 is adapted to pass through ram receiving passage 18 and is used to
selectively block
5 axial flow passage 16.
Refen ing to FIG. 2 through 8, there is a conductor tube assembly 58 that has
a dual
walled first conductor tube 60 (consisting of an inner tube 61 and an outer
sleeve 63)
connected to body 12 and a dual walled second conductor tube 62 (consisting of
an inner tube
69 and an outer sleeve 71) connected to closure 20. Referring to FIG. 3,
conductor tube
assembly 58 defines a first flow path 64 indicated by arrows 65. First flow
path 64 is shown
as commencing at 48A, to confirm the fact it is in fluid communication with
first hydraulic
fluid port 48B. Referring to FIG. 2, conductor tube assembly 58 also defines a
second flow
path 66 indicated by arrows 67. Second flow path 66 is shown as convnencing at
50A, to
conflrm the fact it is in fluid communication with second hydraulic fluid port
50B.
Referring to FIG. 6 and 7, conductor tube assembly 58 is capable of telescopic
extension. Upon relative telescopic extension of conductor tube assembly 58,
closure 20 is
carried away from body 12. Conductor tube assembly 58 has a first operating
mode when
the closure lock (bolts 29) is in the locking position and conductor tube
assembly 58 is
precluded from telescoping and a second operating mode when the closure lock
is in the
release position (by removing bolts 29) and conductor tube assembly 58 is &+ee
to telescope.
The first operating mode will now be discussed. Referring to FIG. 4, when
hydraulic
fluid is supplied at 48A it flows along first flow path 64 as shown by arrows
65, passes into
first hydraulic fluid port 48B and acts against first face 44 of piston 38 to
cause piston 38 to
move in the first direction 49. Referring to FIG. 3, as piston 38 moves in
first direction 49
the area of second chamber 42 diminishes, with hydraulic fluid being
concurrently exhausted
from second chamber 42 through second fluid port 50B (best seen in FIG. 5)
passing along
second flow path 66 and out 50A to a hydraulic fluid source (not shown).
Referring to FIG.
2, when hydraulic fluid is supplied at 50A, it flows along second flow path 66
as shown by
arrows 67, passes into second hydraulic fluid port 50B and acts against second
face 46 of
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piston 38 to cause piston 38 to move in the second direction 51. Referring to
FIG. 5, as
piston 38 moves in second direction 51 the area of first chamber 40
diminishes, with
hydraulic fluid being concurrently exhausted from first chamber 40 through
first fluid port
48B passing along first flow path 64 and out 48A to a hydraulic fluid source
(not shown).
The second operating mode will now be discussed. Referring to FIG. 6 and 7, in
this
second operating mode, the closure lock is released (by removing bolts 29) and
conductor
tube assembly 58 is free to telescope. Referring to FIG. 6, when hydraulic
fluid is supplied at
48A to first flow path 64, the hydraulic fluid telescopically moves conductor
tube assembly
58 and carries closure 20 away from body 12 to an open position, as shown by
arrows 65.
Once conductor tube assembly 58 has been extended, the continued supply of
hydraulic fluid
will pass to hydraulic cylinder 32 at first hydraulic fluid port 48B to cause
piston 38 to move
in first direction 49, as previously described with reference to FIG. 3.
Referring to FIG. 7,
when hydraulic fluid is supplied at 50A to second flow path 66, as shown by
arrows 67, the
hydraulic fluid first moves piston 38 in the second direction 51, as described
with reference to
FIG. 5. The continued supply of hydraulic fluid moves conductor tube assembly
58 carrying
closure 20 toward body 12 back to a closed position.
Referring to FIG. 2 through 5, as depicted, first conductor tube 60 and second
conductor tube 62 are each dual walled tubes having inner passages 68 and 70,
and outer
annular passages 72 and 74, respectively. Referring to FIG. 4, first flow path
64 has
hydraulic fluids entering at 48A passing along inner passage 68 of first
conductor tube 60 and
then along outer annular passage 74 of second conductor tube 62 to first
hydraulic port 48B.
Referring to FIG. 2, second flow path 66 has hydraulic fluids entering at 50A
passing along
outer annular passage 72 of first conductor tube 60 and then along inner
passage 70 of second
conductor tube 62 to second hydraulic port 50B.
Referring to FIG. 8 through 10, a hydraulic flow restrictor 75 is provided
along
second flow path 66 that is adapted to restrict the speed at which conductor
tube assembly 58
telescopically extends to open closure 20. Referring to FIG. 8, conductor tube
assembly 58 is
slowed by flow restrictor 75, as conductor tube assembly 58 approaches full
extension. Port
76 is in fluid communication with second chamber 42 until it enters
restriction 75, which
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abruptly restricts fluid flow providing a braking action. Referring to FIG. 9,
as extension
continues due to forward momentum, port 76 enters flow restrictor cavity 78
and a limited
flow is restored as conductor tube assembly 58 comes to rest. FIG. 10 shows
the final resting
position of conductor tube assembly 58 and flow restrictor 74, with conductor
tube assembly
58 fully extended.
In this patent document, the word "comprising" is used in its non-limiting
sense to
mean that items following the word are included, but items not specifically
mentioned are not
excluded. A reference to an element by the indefinite article "a" does not
exclude the
possibility that more than one of the element is present, unless the context
clearly requires that
there be one and only one of the elements.
It will be apparent to one skilled in the art that modifications may be made
to the
illustrated embodiment without departing from the spirit and scope of the
invention as
hereinafter defined in the Claims.
