U.S. patent number 3,647,174 [Application Number 05/075,360] was granted by the patent office on 1972-03-07 for blowout preventer.
This patent grant is currently assigned to Hydril Company. Invention is credited to Robert K. LeRouax.
United States Patent |
3,647,174 |
LeRouax |
March 7, 1972 |
BLOWOUT PREVENTER
Abstract
Blowout preventers of the ram-type, each having a bonnet which
is detachably connected to the preventer body, and which bonnet is
movable away from the preventer body to expose the ram therewith
for permitting removal of the ram from the preventer for
replacement or repair, wherein the ram piston and cylinder which
are operable for moving the ram to and from its open and closed
positions when the bonnet is secured to the preventer body are also
operable for moving the bonnet away from and towards the preventer
body when the bonnet is disconnected from the body. Detent means
are provided for resisting relative movement between the ram and
the body when the ram is in the open position and the bonnet is
disconnected from the body, whereby the bonnet can be moved away
from the body to the exposed ram position and then returned to
reengage the bonnet with the body. Flexible hydraulic fluid
conductor means is provided for operating the piston and for moving
the cylinder relative to the piston.
Inventors: |
LeRouax; Robert K. (Harris
County, TX) |
Assignee: |
Hydril Company (N/A)
|
Family
ID: |
22125188 |
Appl.
No.: |
05/075,360 |
Filed: |
September 25, 1970 |
Current U.S.
Class: |
251/1.3; 91/217;
251/31; 277/325; 92/128; 277/323 |
Current CPC
Class: |
E21B
33/062 (20130101) |
Current International
Class: |
E21B
33/06 (20060101); E21B 33/03 (20060101); E21b
029/00 (); F16k 003/02 () |
Field of
Search: |
;251/1,146 ;166/97,224
;277/9,127 ;91/54,217 ;92/128 ;285/138,141 ;137/315 |
References Cited
[Referenced By]
U.S. Patent Documents
Primary Examiner: Nelson; M. Cary
Assistant Examiner: Matthews; David R.
Claims
I claim:
1. A blowout preventer, comprising:
a blowout preventer body having a central bore therethrough through
which well pipe may pass, and a ram opening through the wall of
said body on at least one side of said central opening and
communicating with said central opening;
a ram for said ram opening;
a bonnet detachably connected to said body over said ram opening
and adapted to receive said ram when it has been moved to an open
position out of said central opening;
an operating cylinder connected to said bonnet and movable
therewith;
a piston operably disposed in said cylinder and having a rod
connected therefrom through said bonnet to said ram;
fluid pressure means for supplying fluid under pressure to either
side of each piston for controlling its movements to thereby
control the movements of said ram to and from a closed position
wherein said ram extends into said central opening in said
preventer body and an open position wherein said central opening is
unobstructed and said ram is disposed outwardly of said ram opening
of said body; and
resistance means for resisting relative movement between said ram
and said body when said bonnet therewith is disconnected from said
preventer body whereby said bonnet can be moved away from said body
by introducing fluid pressure into said operating cylinder
outwardly of said piston to thereby expose said ram for removal
from the preventer.
2. The structure set forth in claim 1, wherein:
said resistance means also resists relative movement between said
ram and said body when fluid pressure is introduced into said
operating cylinder inwardly of said piston to return said bonnet
from the open ram-exposed position to the closed position in
contact with said body.
3. The structure set forth in claim 1, wherein said resistance
means includes:
coacting detent means on said rod and said body which are
releasably engageable when said ram is in said open position;
said detent means providing sufficient resistance in the engaged
position to prevent movement of said rod and said ram therewith
relative to said body during outward movement of said bonnet
relative to said body; and
said detent means being releasable upon the application of fluid
pressure outwardly of said piston in said cylinder when said bonnet
is secured to said body.
4. The structure set forth in claim 3, wherein said detent means
includes:
a resiliently movable member on one of said body and said rod;
and
a detent on the other of said body and said rod.
5. The structure set forth in claim 3, wherein:
said body has an extension projecting into said bonnet and having a
portion of said detent means therewith disposed outwardly of said
ram for engagement with the other part of said detent means on said
rod.
6. The structure set forth in claim 5, wherein:
said extension of said body is disposed for supporting said ram
when said ram is in said open position.
7. The structure set forth in claim 1, including:
stop means for preventing movement of said ram relative to said
body during inward movement of said bonnet relative to said
body.
8. The structure set forth in claim 7, wherein said stop means
includes:
coacting stop surfaces on said piston rod and said body which are
engageable when said ram is in said open position.
9. The structure set forth in claim 1, wherein said fluid pressure
means includes:
two fluid conduits in said body and extending to said cylinder,
with one of said conduits establishing fluid communication with one
side of said piston and with the other of said conduits
establishing fluid communication with the other side of said
piston.
10. The structure as set forth in claim 9, wherein at least one of
said fluid conduits includes:
a flexible conduit section between said body and said cylinder
which is adapted to expand when said bonnet is moved away from said
body and to contract to its smallest dimension when said bonnet is
returned into contact with said body.
11. The structure set forth in claim 10, wherein said flexible
conduit section comprises:
a coiled hose mounted between said body and said cylinder.
12. The structure set forth in claim 10, wherein said flexible
conduit section comprises:
a hinged conduit between said body and said cylinder which is
folded to its smallest dimension when said bonnet is in contact
with said body and is expanded by unfolding when said bonnet is
moved away from said body.
13. The structure set forth in claim 10, including:
a protective member carried by said body and covering at least the
upper part of said flexible conduit section for protecting same
from damage when said bonnet is in the open ram-exposed
position.
14. A blowout preventer, comprising:
a blowout preventer body having a central bore therethrough and a
ram opening through the wall of said body on at least one side of
said central opening and communicating with said central
opening;
a ram for said ram opening;
a bonnet detachably connected to said body over said ram opening
and adapted to receive said ram when it has been moved to an open
position out of said central opening;
an operating cylinder connected to said bonnet and movable
therewith;
a piston operably disposed in said cylinder and having a rod
connected therefrom through said bonnet to said ram;
two fluid conduits in said body and extending to said cylinder,
with one of said conduits establishing fluid communication with one
side of said piston and with the other of said conduits
establishing fluid communication with the other side of said
piston; and
each of said fluid conduits having a flexible conduit section
between said body and said cylinder which is adapted to extend when
said bonnet is moved away from said body and to retract when said
bonnet is returned into contact with said body.
15. The structure set forth in claim 14, wherein said flexible
conduit section comprises:
a coiled hose mounted between said body and said cylinder.
16. The structure set forth in claim 14, wherein said flexible
conduit section comprises:
a hinged conduit between said body and said cylinder which is
extended by unfolding when said bonnet is moved away from said body
and is retracted by folding.
17. The structure set forth in claim 14, including:
a protective member carried by said body and covering at least the
upper part of said flexible conduit section for protecting same
from damage when said bonnet is in the open ram-exposed
position.
18. A blowout preventer, comprising:
a blowout preventer body having a central bore therethrough through
which well pipe may pass, and a ram opening through the wall of
said body on at least one side of said central opening and
communicating with said central opening;
a ram for said ram opening;
a bonnet detachably connected to said body over said ram opening
and adapted to receive said ram when it has been moved to an open
position out of said central opening;
an operating cylinder connected to said bonnet and movable
therewith;
a piston operably disposed in said cylinder and having a rod
connected therefrom through said bonnet to said ram;
fluid pressure means for supplying fluid under pressure to either
side of each piston for controlling its movements to thereby
control the movements of said ram to and from a closed position
wherein said ram extends into said central opening in said
preventer body and an open position wherein said central opening is
unobstructed and said ram is disposed outwardly of said ram opening
of said body; and
a pair of support members carried by said body and extending into
said bonnet for supporting said bonnet when in said open
ram-exposing position; said support members having their upper
surfaces lying in a plane substantially at or below the lowermost
surface of said ram for permitting lateral movement of said ram for
removal from said rod.
19. The structure set forth in claim 18, including:
means for releasably mounting said ram on said rod for releasable
movement therefrom in either a vertical or lateral direction.
20. The structure set forth in claim 18, wherein:
said fluid pressure means comprises a pair of flexible fluid
conduit sections each of which is adapted to expand when said
bonnet moves away from said body and assume its smallest dimension
when said bonnet is in contact with said body; and
each of said support members is disposed above one of said flexible
fluid conduit sections to protect same from damage when said bonnet
is in said open ram-exposing position.
Description
BACKGROUND OF THE INVENTION
The field of this invention is blowout preventers.
It often becomes necessary or desirable to replace the rams, or at
least the sealing components thereof, in a blowout preventer while
the preventer is in the field in its normally mounted position at a
wellhead. In the past, various efforts have been made to facilitate
such field removal of the rams for replacement and/or repair,
examples of which are shown in U.S. Pats. Nos. 2,752,119;
2,912,214; and 3,272,222. In the blowout preventer constructions of
such prior art, the rams were operated normally by the main
hydraulic system, and a separate additional hydraulic system was
required to move the blowout away from and back to the preventer
body. Such prior art constructions required telescoping tubes for
carrying the hydraulic fluid to effect the movements of the bonnet
relative to the head, which tubes had to have polished or smooth
external surfaces to maintain a fluid seal during the telescoping
movements. Such smooth surfaces were always exposed to damage such
as scratches, indentations and nicks caused by tools and parts
hitting the tubes when the bonnet and ram were in the open exposed
position. If the damage was severe enough, destruction of the seals
soon followed, with consequent leaks of hydraulic fluid, and
causing the equipment to malfunction or become inoperative.
Furthermore, because of the use of the supplemental hydraulic
system for moving the bonnet in such prior art blowout preventers,
the overall weight of the preventer was excessive, and the force
exerted in closing the bonnet in sealing contact with the head was
relatively small. Also, an excessively large number of fluid seals
was required in such constructions. Additionally, the location of
such telescoping tubes in the prior art blowout preventers
interfered with and prevented lateral removal of the rams from the
preventer, so that it was very difficult, and often impossible, to
remove the rams from a lower preventer in a vertically stacked
double preventer assembly without first extending the bonnet in the
upper preventer and removing the upper rams therefrom.
SUMMARY OF THE INVENTION
A blowout preventer of the ram-type having piston and cylinder
means for effecting normal opening and closing of the rams and for
also effecting movements of the preventer bonnet away from and back
to the preventer body when the bonnet is disconnected from the
body, whereby increased power is available for opening and closing
the bonnet, a lighter weight structure is possible and fewer seals
are required, as compared to the prior art. Additionally, the
telescoping tubes for the supplemental bonnet hydraulic system used
in the prior art are not necessary with the present invention,
thereby solving the problem of the failure of such prior art
preventers when the telescoping tubes were damaged. Preferably,
flexible hydraulic lines are utilized in the blowout preventers of
this invention rather than telescoping tubes.
The blowout preventer of this invention is also constructed so that
the rams can each be removed vertically or laterally from the
preventer, whereby the rams in a lower preventer of a vertically
stacked double preventer can be removed without opening the bonnets
and removing the rams of the upper preventer, thereby saving
man-hours and needless effort.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is an elevation of the blowout preventer of this invention,
illustrating the preventer with the left-hand bonnet in the
ram-exposed position, and the right-hand bonnet in the normal
connected position;
FIG. 2 is an end view of the blowout preventer of this
invention;
FIGS. 3, 4, and 5 are cross-sectional views of the blowout
preventer of FIG. 1, showing the left-hand portion thereof, with
FIG. 3 illustrating the preventer in the normal operating position
with the ram closed, FIG. 4 showing the preventer in the normally
operating position with the ram in the open position; and FIG. 5
showing a view taken on line 5--5 of FIG. 1 to illustrate the
bonnet in the open, ram-exposing position;
FIGS. 6A, 6B and 6C are vertical sectional views taken from the
left hand to the right-hand end of the left-hand portion of the
blowout preventer of this invention, illustrating in detail one of
the rams with its associated structure;
FIG. 7 is a sectional view taken on line 7--7 of FIG. 6C;
FIG. 8 is an enlarged sectional view taken on line 8--8 of FIG. 4,
illustrating in detail one form of the flexible fluid conduit which
is preferably utilized with the blowout preventer of this
invention;
FIG. 9 is an end view of a modified ram, with a portion of a piston
rod detachably connected thereto, and illustrating in particular
the construction of the ram to effect removal of the ram from the
piston rod either vertically or laterally;
FIG. 10 is a cross-sectional view illustrating a modified form of
the flexible fluid conduits which may be utilized in place of the
flexible fluid conduit illustrated in FIG. 8 in particular;
FIG. 11 is an elevation, partly in section, illustrating further
details of the modified flexible fluid conduits of FIG. 10; and
FIG. 12 is a view similar to FIG. 10, but illustrating the flexible
conduits in their collapsed or smallest dimension position with the
bonnet in contact with the preventer body so that the normal ram
movements may be conducted.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
In the drawings, the letter A designates generally the blowout
preventer of this which is connected in the usual way to well
casing or pipe P, using bolts 10 which extend through a flange 11
on each section of the casing P into a body B of the preventer A.
The body B is of conventional construction and includes a central
longitudinal opening 12 therethrough which is aligned with the
vertical opening through the casing or pipe P. The body B also has
laterally disposed ram openings 14 which are disposed on
diametrically opposite sides of the body B, extending entirely
through the wall of such body B, and communicating with the
longitudinal opening 12. A ram R of any suitable construction is
mounted so that it is laterally movable in one of the lateral ram
openings 14 and it has any suitable sealing assembly 15 formed of
rubber or similar material therewith in the usual manner. The rams
R are adapted to be moved laterally from the closed position (FIGS.
3 and 6C) in which position they close off fluid flow through the
central opening 12, to an open position (FIG. 4) in normal
operation, wherein the central bore 12 is open for performing
normal well operations therethrough.
Furthermore, as will be explained more in detail, the blowout
preventer A of this invention is constructed so that a bonnet H is
mounted so as to enclose each of the rams R on each side of the
blowout preventer body B. Each of the bonnets or heads H is
releasably connected to the body B with bolts 18 or any other
suitable releasable securing means in the known manner. An
operating cylinder C is secured to the bonnet H by bolts 20 or
other suitable securing means (FIG. 1) so that the cylinder C is
movable with the bonnet H. A piston D is slidably positioned within
the cylinder C (FIGS. 3, 4, 5 and 6B). Each piston D is connected
to one of the rams R by a piston rod 22 so that movements of the
piston D are transmitted to the ram R connected therewith. As will
be more fully explained, fluid pressure is supplied to the cylinder
C, preferably through fluid conduits F-1 and F-2 so as to move the
piston D within the cylinder C for moving the ram R therewith to
and from the closed and open positions. Also, when the bonnet H is
disconnected from the body B, the fluid pressure in the cylinder C
is utilized to move the cylinder C relative to the piston D (FIG.
5) for moving the bonnet H away from the preventer body B so as to
expose the ram R for removal. The fluid pressure is also utilized
for the return of the cylinder C relative to the piston D to return
the bonnet H to the closed position (FIG. 4) for connecting same to
the preventer body B for normal operations of the ram R. It will be
understood that throughout this description, the structure and
operation for only the left-hand ram R and the parts therewith are
explained in detail, since the structure and operation of the other
ram and parts therewith are generally the same.
Considering the invention more in detail, the left hand ram R (FIG.
1) is illustrated as having a generally oval shape, although it may
be cylindrical or of any other suitable shape so as to properly
function within its ram opening 14 in the body B. The ram R is
releasably connected to the piston rod 22 by means of a rod
connector pin 24 having an enlarged button 24a. The connector 24
may be integral with the rod 22, or it may be threaded thereto as
indicated at 24b (FIG. 6C). An annular projection 24c is also
formed with the connector 24 and is disposed in proximity to the
end of the piston rod 22, for a purpose to be hereinafter
explained. As best seen in FIG. 9, the ram R is formed with a
laterally extending slot 25 and a vertically extending slot 26. The
dimensions of the button connector 24a are larger than the diameter
of the shaft portion of the connector 24 so that the button 24a
fits within an enlarged channel 25a of the slot 25, or an enlarged
channel 26a of the vertical slot 26. The diameter of the shaft
portion of the connector 24 is slightly smaller than the width of
the slot 25 or the slot 26. The ram R can thus be moved
transversely relative to the connector 24 as the shaft portion of
the connector 24 moves through the slot 25 and the button 24a moves
through the enlarged channel portion 25a of the slot 25. Since the
slot 25 and its channel 25a extend entirely across the ram R, the
ram R may be removed from the connector 24 and thus from the piston
rod 22 in either lateral direction. Similarly, the ram R may be
removed by raising it vertically so that the shaft portion of the
connector 24 passes through the slot 26 and the button 24a passes
through the channel portion 26a of the slot 26. To facilitate the
positioning of the ram R at the proper central position with
respect to the connector 24, a recess 25b is formed in the upper
wall of the slot 25 to receive a part of the connector 24 (FIG. 9)
when the connector 24 is in the proper position at approximately
the midpoint of the ram R. In FIG. 9, the connector button 24a and
a portion of the shaft of the connector 24 are illustrated in
dotted lines to show the position thereof during the removal of the
ram R transversely, using the slot 25.
In the preferred form of the invention illustrated in FIGS. 6A-6C,
the body B has an extension 30 which is welded or is otherwise
secured to the body B, and which includes an upstanding resistance
member 31 having an annular recess 31a therein, which forms a part
of a detent means for resisting movement of the ram R relative to
the body B when the bonnet H is disconnected from the body B, as
will be more fully explained. The other part of the detent means or
resistance means is a flexible split ring 32 (FIGS. 6C and 7) which
is mounted at the end of the rod 22 near the ram R.
The ring 32 is split as indicated at 32a (FIG. 7) so that is can
contract in its external diameter to enter the recess 31a. Its
inherent resiliency normally urges it to a diameter which is
greater than the diameter of the rod 22 so that when the ring 32 is
in the recess 31a, it resists movement of the rod 22 relative to
the sleeve 31 and thus relative to the body B. The resilient ring
32 fits within an annular groove 22a having a plurality of stops
22b therein. However, it should be understood that any other
suitable arrangement for providing a resiliently contractable and
expansible member to enter the recess 31a to serve as the detent
means or resistance means may be utilized. It should also be noted
that the body extension 30 may serve as a shelf or additional
support for the ram R when it is in the exposed position, although
such additional support from the extension 30 is not necessary
since the bonnet H and the parts therewith including the ram R are
adequately supported by a pair of support tubes 35 when the bonnet
H is in the open ram-exposing position (FIG. 5). It should also be
pointed out that the support tubes 35 are located at the lower end
of the body B so that the upper surfaces of such support tubes 35
are substantially at or are lower than the lower part of the ram R
so that the ram R may be removed laterally from the rod 22 (FIG.
1).
Any suitable seal is provided between the bonnet H and the rod 22
to prevent the well fluid from entering the operating cylinder C,
one form of which is illustrated in FIG. 6B and includes an annular
lip type seal ring 36 formed of rubber or similar material which
normally holds the well pressure. A secondary seal 37 of
conventional construction which is energized by the injection of
plastic backs up the lip seal 36. A third seal is provided by an
O-ring 38. A weep hole 39 which has a hole 39a in communication
therewith is provided to the atmosphere between the secondary seal
and the O-ring 38 to make certain that there is no communication
between the well fluid and the operating cylinder C.
A cylinder liner 40 is mounted on the bonnet H to provide a smooth
internal cylindrical surface 40a in which the piston D may slide
during relative reciprocatory movement of the piston D and the
cylinder C. The external surface 40b of the cylinder liner 40 has a
diameter which is less than the internal diameter of the main
portion of the cylinder C so as to provide an inlet passage 41
which communicates with the interior of the cylinder liner 40 at
the outer end 40c. Thus, when it is desired to introduce fluid
under pressure into the cylinder C outwardly of the piston D, the
fluid under pressure is introduced through the fluid conduit F-2 as
will be more fully explained, from a source of the fluid pressure
(not shown), whereby the fluid under pressure is introduced through
the passage 41 at the end 40c of the cylinder 40.
When it is desired to introduce fluid under pressure into the
cylinder C inwardly of the piston D, the fluid conduit F-1 is
utilized.
Considering the fluid conduits F-1 and F-2 more specifically,
reference is made to FIGS. 3-5 and 8 for details of one form of
such conduit construction. Fluid under pressure is introduced into
the body B through an inlet passage 50 which communicates with a
flexible coiled hose 51, having one end 51a attached to the body B,
and having the other end 51b thereof attached to the head or bonnet
H. In the preferred form of the invention, the flexible conduit
section of hose 51 is formed of rubber or any other suitable
material which is capable of being expanded or extended from a
retracted position (FIGS. 3 and 4) to an expanded position (FIG.
5). The fluid conduit section 51 fits within one of the support
tubes 35 which serves as a protector for the hose 51 when the
bonnet H is in the ram-exposing position (FIG. 5).
The bonnet H has a passage 52 which leads from the end 51b of the
hose 51 to the cylinder C inwardly of the piston D so that whether
the hose or conduit section 51 is in the extended position of FIG.
5, or in the retracted position of FIG. 8, the fluid may flow under
pressure from the passage 50 through the conduit section 51 and the
passage 52 into the cylinder C.
The fluid conduit F-2 is constructed in an identical manner to the
fluid conduit F-1, except that the hose or fluid conduit section 51
of the conduit F-2 connects with a passage 53 in the bonnet H which
establishes communication with the passage 41 in the cylinder C so
as to direct the fluid under pressure to the area of the cylinder C
outwardly of the piston D. Otherwise, the parts which are the same
in the two fluid conduit systems F-1 and F-2 have like numerals and
other designations. The details of the flexible hose or conduit
section 51 which are illustrated in FIG. 8 have been specifically
taken from line 8-8 of FIG. 4, but it will be understood that such
details are likewise applicable to the flexible hose or conduit
section 51 of the fluid conduit F-2, substituting the passage 53
for the passage 52 shown in FIG. 8.
For locking the ram R in the closed position (FIG. 3), a locking
assembly is provided, the details of which are shown in FIGS. 6A
and 6B. The locking assembly includes a locking sleeve 60 which has
a nut section 60a welded or otherwise secured thereto, with
internal threads 60b in threaded engagement with external threads
61a on a lock screw rod 61. A vent hole 61b is provided in the lock
screw rod 61 for the release of fluid which is trapped when the
lock sleeve 60 is unthreaded to the locked position. Under normal
operating conditions with the head or bonnet H secured to the body
B, the lock sleeve 60 and the lock screw rod 61 are in the
telescoped or closed position illustrated in FIG. 6A and 6B and
they more together with the piston D. The sleeve 60 moves through
any suitable seals 62 (the outer one of which is a wiper) in the
operating cylinder C, and the outer end of the sleeve 60 has a
solid cap 60c which is welded or is otherwise affixed thereto
beyond the extremity of the lock screw rod 61. Such cap 60c
preferably has a square cross section so as to form wrench flats on
its external surface to facilitate the rotation of the sleeve 60
and its threaded section 60a relative to the lock screw 61, as will
be more fully explained. A protector tube 63 is welded or is
otherwise affixed to the operating cylinder C for receiving the
sleeve 60 to protect same against damage when the sleeve 60 is in
the extended position.
The lock sleeve 60 preferably is provided with an antifriction stop
ring or washer 60d (FIG. 6B) which is loosely positioned on the
lock sleeve section 60 to form an annular surface which provides
antifriction and prevents galling by contacting a machined surface
64 on the inside wall at the outer end of the operating cylinder C
when the maximum extend of outward movement of the sleeve 60
relative to the cylinder C has been reached. Thus, when the piston
D is in the inner position, with the ram R in the closed position
(FIG. 3), the cap 60c may be rotated, using a wrench or any other
suitable tool. The rotation of the sleeve 60 causes it to unthread
relative to the lock screw rod 61, since the rod 61 is integral
with, or connected with the rod 22 which is prevented from rotating
due to the square or rectangular shape of the connector button 24a
and the oval shape of the ram R. It will be appreciated that any
other suitable means for preventing the rotation of the lock screw
61 may be provided so as to obtain the relative longitudinal
unthreading of the sleeve 60. The sleeve 60 is unthreaded until the
stop ring 60d engages the annular seating surface 64, at which
point the piston D is prevented from moving outwardly from its
inner position. It is to be noted that the protector sleeve 63 is
omitted from FIGS. 1-5 for purposes of illustration, but it is
shown in FIG. 6A in its preferred embodiment. Such sleeve 63
protects the sleeve 60 when it is in the extended position.
In the operation or use of the apparatus of this invention, the
bonnet or head H is normally secured to the body B by means of the
connecting bolts 18 or other suitable attaching means. Therefore,
for normal operation of each ram R, fluid under pressure is
introduced into the cylinder C outwardly of the piston D for moving
the ram R inwardly to completely close the longitudinal central
opening 12 in the body B. It will be understood that when the ram R
is a "blind" ram, it engages a ram of the same configuration in the
diametrically opposite position for completing the closure of the
opening 12, as will be well understood by those skilled in the art.
If the ram R is shaped for fitting around the external surface of a
well pipe in the bore or opening 12, then the two opposed rams will
close off the opening 12 around such pipe, as will be understood by
those skilled in the art.
When it is desired to move each of the rams R to the open position
so as to leave the bore or opening 12 completely open, fluid under
pressure is introduced through the fluid conduit F-1 into the
cylinder C inwardly of the piston D to thereby move the piston D
outwardly to the position shown in FIG. 4 wherein the ram R is
displaced outwardly with its innermost edge beyond the edge of the
body B.
Under normal operations, the bonnet H thus remains connected to the
body B, and the ram R on each side of the body B is moved back and
forth as desired for controlling the opening and closing of the
central or longitudinal opening 12 through the body B. The piston D
and, therefore, the ram R on each side of the body B may be locked
in the closed position by the unthreading of the lock sleeve 60
relative to the threaded lock screw rod 61, as previously
explained.
When it is desired to move the ram R to the exposed position (FIG.
5) for the removal of the ram R from the preventer A, the ram R is
first moved to the open position illustrated in FIG. 4, forcing the
resilient ring 32 to enter the detent recess 31a (FIG. 4). In that
position, the ram R is displaced outwardly of the body B.
Thereafter, the bolts 18 or other suitable connecting means between
the bonnet H and the body B are disconnected, and fluid under
pressure is supplied through the fluid conduit F-2, including the
flexible conduit section 51 to the cylinder C outwardly of the
piston D. Since the resistance provided by the ring 32 in the
detent recess 31a is greater than the frictional resistance between
the bonnet H and the tubes 35, such fluid pressure acts to move the
cylinder C outwardly while the piston D remains stationary. Since
the operating cylinder C and the bonnet H are connected together by
the bolts 20 or other suitable connecting means, the outward
movement of the operating cylinder C moves the bonnet H outwardly
therewith so as to fully expose the ram R (FIG. 5). It is to be
noted that the flexible hoses or conduit sections 51 in the two
fluid conduits F-1 and F-2 are fully protected by the support tubes
35 when the ram R is exposed for removal. The bonnet H and parts
therewith are supported by the support tube 35. If desired,
supplemental support may be provided for the ram R by resting same
on the body extension 30, as previously explained.
When the ram R is in the ram-exposed position (FIG. 5), it may be
removed either laterally in either direction or vertically, as
previously explained. Since the ram R may be removed laterally, it
is possible to remove the ram R even though it is the lower ram in
a double blowout preventer with a pair of preventers in a vertical
stack, without removing the upper ram in the stack, as is required
in the prior art.
To return the bonnet H to the closed position (FIG. 4), fluid under
pressure is introduced through the fluid conduit F-1 so that such
fluid enters the operating cylinder C inwardly of the piston D.
Outward movement of the piston D is prevented by the engagement of
the projection 24c with the sleeve 31 so that the fluid under
pressure inwardly of the piston D forces the cylinder C and bonnet
H inwardly from the outer open position (FIG. 5) to the inner
closed position (FIG. 4). The bolts 18 or other suitable connecting
means are then reattached to secure the bonnet or head H to the
body B so that normal ram operations may thereafter be
continued.
It should be noted that instead of using the shoulder 24c for
engagement with the sleeve 31, when returning the bonnet H to the
closed position, the ram R itself may engage the sleeve 31 to
resist outward movement of the piston D.
FIGS. 10-12 illustrate a modified form of the blowout preventer of
this invention, with the body B-1, ram R-1, bonnet H-1, and
cylinder C-1, corresponding to the body B, ram R, bonnet H and the
operating cylinder C of FIGS. 1-9, but with certain modifications
as will be explained. The fluid conduit system F-1 and F-2
illustrated in FIGS. 10-12 may be essentially identical with those
heretofore described in connection with FIGS. 3-5 and 8, except
that the flexible conduit section 51 of such figures is replaced by
a hinged flexible conduit section 70. Each of the flexible hinged
conduit sections 70 has pivoted connections 70a and 70b, with a
hinge or pivot connection 70c joining rigid tubes 70d and 70e. The
flexible conduit section 70 communicates with a fluid passage 150
in the body B-1 through which fluid under pressure is supplied from
a source (not shown). The fluid conduit section 70 also
communicates with a passage 152 in the bonnet H-1 which corresponds
with the passage 52 in the bonnet H for supplying fluid under
pressure to the operating cylinder C-1 inwardly of a piston D in
the same manner as heretofore described in connection with FIGS.
1-9.
Support members 135 having a substantially "U" shape are connected
to the body B-1 and extend over the top of each of the sections 70
to protect same when the bonnet H-1 is in the open ram-exposing
position (FIG. 10). The bonnet H-1 has a suitable slot or recess 75
formed therein for each of the support members 135 to thereby
permit movement of such support members 135 with respect to the
bonnet H-1 when the bonnet H-1 is in the closed position (FIG. 12).
The upper surface of each support member 135 is disposed
substantially at or below the lower part of the ram R-1 (FIG. 11)
to facilitate the removal of the ram R-1 laterally in either
direction if desired. Also, the body B-1 has a recess 76 for each
of the hinge sections 70, and the bonnet H-1 has a recess 77 for
each of the hinge sections 70 so as to permit a collapse or
contraction of each of the hinge sections 70 to its smallest
dimension when the bonnet H-1 is in contact with the body B-1 (FIG.
12). It is to be noted that the support members 135 perform the
same function as the tubes 35 in FIG. 5, in that such support
members 135 support the bonnet H-1 and the parts therewith when the
bonnet H-1 is in the open ram-exposing position (FIG. 10).
Although the resistance means or detent means provided by the
resilient ring 32 and the locking recess 31a may be utilized in the
modified form of the apparatus of FIGS. 10-12 if desired, FIG. 11
illustrates such modified structure with another type of resistance
or detent means. Thus, the modified resistance or detent means of
FIGS. 10-11 includes a resiliently urged member such as a ball 80
which is urged upwardly by a spring 81 mounted at any suitable
location in the body B-1 for engagement with a portion of the ram
R-1. After the ram R-1 has been moved to the open position so as to
be outwardly of the body B-1, the ball 80 is resiliently urged
upwardly so as to provide resistance to the return of the ram R-1
inwardly (FIG. 11). Thus, when the bonnet H-1 is thereafter
disconnected from the body B-1, fluid under pressure which is
supplied through the fluid conduit F-2 into the operating cylinder
C-1 outwardly of the piston D acts to move the bonnet H-1 outwardly
to fully expose the ram R-1. The ram R-1 also has a shoulder 83
which is adapted to engage a body extension 84 when fluid under
pressure is introduced through the fluid conduit F-1 for returning
the bonnet H-1 to the closed position.
The foregoing disclosure and description of the invention are
illustrative and explanatory thereof, and various changes in the
size, shape, and materials as well as in the details of the
illustrated construction may be made without departing from the
spirit of the invention.
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