U.S. patent number 3,744,749 [Application Number 05/144,556] was granted by the patent office on 1973-07-10 for blowout preventer with ram support and guide means.
This patent grant is currently assigned to Hydril Company. Invention is credited to Robert K. Le Rouax.
United States Patent |
3,744,749 |
Le Rouax |
July 10, 1973 |
BLOWOUT PREVENTER WITH RAM SUPPORT AND GUIDE MEANS
Abstract
A blowout preventer having new and improved means for supporting
and guiding each ram in its travel to and from the open and closed
positions whereby more uniform support, anti-cocking, and
anti-heeling of the ram during such travel are accomplished.
Inventors: |
Le Rouax; Robert K. (Houston,
TX) |
Assignee: |
Hydril Company (Houston,
TX)
|
Family
ID: |
22509117 |
Appl.
No.: |
05/144,556 |
Filed: |
May 18, 1971 |
Current U.S.
Class: |
251/1.3;
277/325 |
Current CPC
Class: |
E21B
33/062 (20130101) |
Current International
Class: |
E21B
33/06 (20060101); E21B 33/03 (20060101); E21b
033/06 () |
Field of
Search: |
;251/1
;277/73,126,127,129 ;166/82,84,86 |
References Cited
[Referenced By]
U.S. Patent Documents
Primary Examiner: Schwadron; Martin P.
Assistant Examiner: Gerard; Richard
Claims
I claim:
1. A blowout preventer, comprising:
a blowout preventer body having a longitudinally extending opening
through which a well pipe is adapted to extend and also having a
laterally extending ram opening in communication with said
longitudinally extending opening and having a lower wall;
a blowout preventer head mounted adjacent to said body and having a
ram cavity in alignment with said ram opening in said body;
a blowout preventer ram disposed for movement in said ram opening
and said ram cavity to and from a closed position wherein the ram
extends into said longitudinally extending opening to assist in
closing flow therethrough and to and from an open position wherein
the ram is retracted from said longitudinally extending
opening;
means with said ram for effecting the ram movements to and from
said closed and open positions;
ram support means with said head and extending into said ram
opening of said body for supporting said ram as said ram travels to
and from its open and closed positions;
ram rail engaging surface on the lower surface of said ram
engageable with said ram support means;
said ram rail engaging surface being formed at the inner end of
said ram and terminating inwardly of the inner end of said ram
support means when said ram is in the closed position;
said ram having a ram recess in longitudinal alignment with said
ram rail engaging surface for receiving said ram support means when
said ram is in the closed position; and
said ram having a lower surface engageable with said lower wall of
said ram opening when said ram is in the closed position.
2. The structure set forth in claim 1, including:
guide means co-acting with said ram for preventing misalignment of
said ram during said travel.
3. The structure set forth in claim 1, wherein said ram support
means includes:
a pair of laterally spaced longitudinally extending support rails
disposed in said head and extending into said ram opening.
4. The structure set forth in claim 3, including:
co-acting guide surfaces on said rails and on said ram for
preventing said rams from rolling and yawing during travel of said
ram on said rails.
5. The structure set forth in claim 3, wherein:
said ram has a pair of said ram rail engaging surfaces, each
engageable with one of said rails upon a predetermined amount of
travel of said ram outwardly from its closed position to lift said
ram upwardly so that the ram is supported solely by said rails upon
continued outward movement of the ram.
6. The structure set forth in claim 5, wherein:
said ram has a pair of said ram recesses, each being aligned with
one of said ram rail engaging surfaces and disposed outwardly of
each of said rail engaging surfaces, which recesses are disposed
over said rails when said ram is in said closed position.
7. The structure set forth in claim 1, including:
means for preventing pitching of said ram when pressure or forces
act on the ram in the closed position.
8. The structure set forth in claim 1, wherein:
the wall of said ram opening has an upper curved section and a
lower curved section; and
the curvature of the external surface of said ram and said curved
sections are substantially the same so that regardless of the
direction of any pressure or force acting on said ram, the external
surface of said ram will be coincidental with one of said curved
sections to thereby prevent pitching of said ram.
9. The structure set forth in claim 8, wherein:
said curved sections are vertically spaced from each other to
permit vertical movement of said ram in said ram opening while
still effecting said coincidental engagement of said external
surface of the ram with each of said curved sections.
10. The structure set forth in claim 9, wherein:
said ram rail engaging surfaces each also provides ram-lifting
means with said ram support means for lifting said ram a distance
approximately equal to said vertical distance between said curved
sections as said ram travels outwardly from the closed position
towards the open position.
11. The structure set forth in claim 1, including:
seal means on said ram engageable with the wall of said ram opening
for sealing therewith when said ram is in said closed position;
and
wiper means for wiping off the wall of said ram opening as said ram
travels to its closed position.
Description
BACKGROUND OF THE INVENTION
The field of this invention is blowout preventers.
In blowout preventers, it is customary to move each ram inwardly to
a closed position and outwardly to an open position using hydraulic
power means. During such inward and outward movements, when the ram
is subjected to misalignment or non-uniform support, a binding of
the ram in the body and/or head may occur, which results in
excessive wear and even malfunctioning.
SUMMARY OF THE INVENTION
The present invention relates to a blowout preventer having new and
improved means for supporting and guiding each ram as it travels
inwardly and outwardly in the blowout preventer body and head,
whereby the ram is uniformly supported during such travel, and
cocking and heeling of the ram are prevented so that the ram
remains properly aligned to avoid binding or malfunctioning of each
ram in the blowout preventer.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a vertical sectional view, partly in elevation, of the
blowout preventer of this invention, illustrating the ram in the
closed position with upward fluid pressure acting thereon;
FIG. 2 is a view similar to FIG. 1, but illustrating the ram in
elevation and in the open position;
FIG. 3 is an enlarged fragmentary view of a portion of the ram and
body illustrated in FIG. 1;
FIG. 4 is an end view taken on line 4--4 of FIG. 1 but with the ram
in a lowered position in FIG. 4 as compared to FIG. 1 to illustrate
in FIG. 4 the position of the ram when there is no upward fluid
pressure acting on the ram; and
FIG. 5 is an end view taken on line 5--5 of FIG. 2.
DESCRIPTION OF THE PREFERRED EMBODIMENT
In the drawings, the letter A designates generally the blowout
preventer of this invention which includes a blowout preventer body
B, a blowout preventer head or bonnet H, a ram R, and means C for
moving the ram R from a closed position (FIG. 1) to an open
position (FIG. 2) and vice versa. As will be explained in detail
hereinafter, the blowout preventer A of this invention provides
means for uniformly supporting the ram R during its travel to and
from the closed and open positions. Also, means are provided for
preventing tilting or cocking of the ram R with respect to the
horizontal central axis of the ram R. Additionally, means are
provided for preventing heeling or tilting of the ram R about the
vertical central axis of the ram R, all of which will be explained
more in detail hereinafter.
Considering the invention more in detail, the blowout preventer
body B is provided with a longitudinally extending bore or opening
10 through which well pipe, wire lines or well tools may pass in
the known manner. The body B also has a laterally extending ram
opening 11 which is of special construction as described
hereinafter. Basically, the ram opening 11 is in alignment with a
ram cavity 12 in the bonnet or head H.
The head or bonnet H is releasably connected to the body B by
releasable bolts 14 which extend through the head H and into the
body B, or by any other suitable attaching means. The head or
bonnet H may be mounted with any known type of support so that it
either swings arcuately with respect to the body B after the bolts
14 are released from the body B so as to expose the ram R when the
ram R is in the closed position (FIG. 2), or the head H may move
outwardly on suitable supports (not shown) after the bolts 14 are
released and with the ram R in the opening position (FIG. 2) to
expose the ram R for the replacement of the ram or its parts. Such
constructions for mounting and supporting the head or bonnet H are
known and form no specific part of the present invention.
The moving means C which is utilized for moving the ram R may be
hydraulic, mechanical, manual or of any other suitable type. As
illustrated in the drawings, such means C includes a cylinder 15
which is connected by bolts (not shown) or any other suitable
securing means to the bonnet or head H in the known manner so that
under normal operating conditions, the cylinder 15 moves with the
head H. A cylinder liner 16 is suitably mounted within the cylinder
15 in the preferred form of the invention, with a piston 17 movable
within such liner 16 in the known manner. The piston 17 is moved
inwardly by hydraulic fluid pr other fluid pressure introduced
through a fluid pressure line 18 into an annular space 19 between
the liner 16 and the cylinder 15 in the known manner. It will be
understood that the hydraulic line 18 is only partially illustrated
and it connects with a source of hydraulic fluid under suitable
pressure. For moving the piston 17 outwardly or in a direction to
the left as viewed in FIG. 1, hydraulic fluid or other fluid under
pressure is introduced through a line 20, a portion of which is
illustrated in the drawings and which is suitably connected to a
source of hydraulic fluid under pressure in the known manner. A
lock screw 22 of known construction is preferably mounted with the
piston 17 for locking the ram R in the closed position, as is well
understood by those skilled in the art. Such lock screw 22 has
threads (not shown) internally of a ram rod 23 which is on the
other side of the piston 17 and which extends into the head or
bonnet ram cavity 12.
The ram rod 23 extends through suitable conventional seals 24, 25
and it has at its inner end a connecting button 26 which is joined
to the rod 23 by a reduced diameter rod portion 27. The shape of
the button 26 is illustrated as being round with a notch 26a in
which a pin 30a extends for preventing relative movement between
the button 26 and the ram R, but the button 26 may be rectangular,
square, or of any other shape so long as it is adapted to fit
within a corresponding slot 30 in the ram R. Thus, the connecting
button 26 is adapted to fit within the slot 30 on the ram R for
holding the ram R during the travel of the piston 17 and the rod 23
therewith. Movements of the piston 17 are directly transmitted to
the ram R through the connecting button 26, but when the bonnet or
head H has been separated from the body B after a release of the
bolts 14 or other connecting means, as is well understood, the ram
R may be removed from the connecting button 26 for replacement or
repair, and a new or repaired ram R may then be placed upon and
connected with the piston 27 through the button 26 in the known
manner.
The ram R has a ram body 40 formed of metal such as steel and it is
formed with a conventional recess 40a for receiving a ram sealing
member 41 formed of rubber with metal retainer plates 42 above and
below the rubber seal 41 for preventing extrusion of the rubber
when it is in the sealing or closed position in engagement with a
corresponding ram seal (not shown) on the opposite ram of the
blowout preventer as will be understood.
The ram body 40 is also formed with a ram groove 40b for receiving
a conventionally shaped ram rubber seal 44 (FIGS. 1 and 2) which
extends over the upper portion of the ram body 40 and extends
downwardly along the sides thereof for engagement with the ends of
the seal 41.
As the ram R is viewed from the end (FIGS. 4 and 5) it has a
generally oval shape in the preferred form of the invention,
although the shape may be round or otherwise suitably shaped as
will be well understood by those skilled in the art. The ram R has
a horizontal central axis indicated by center line 45 and its side
surfaces 40c are formed with a radius from such center line 45. It
is to be noted that the center line 45 has shifted upwardly from
FIG. 4 to FIG. 5 which results from the upward movement of the ram
R as it travels outwardly from its closed position (FIG. 1) to its
open position (FIG. 2), as will be more fully explained
hereinafter.
For supporting the ram R during its travel to and from its opened
and closed positions and for accomplishing the lifting of the ram
R, a pair of horizontally spaced support rails 50 are connected to
the bonnet or head H by means of screws 51 or any other suitable
retaining means. To facilitate construction and mounting of such
rails 50, they preferably are formed integrally with each other
with a connecting plate 50a therebetween (FIGS. 4 and 5). Each of
the guide rails 50 has an upper guide rail supporting surface 50b
which is adapted to engage a corresponding ram guide surface 40d
after the ram R has moved a predetermined distance outwardly from
its closed position so as to effect a lifting of the ram R from the
position shown in FIG. 4 to the position shown in FIG. 5, in which
position the ram R moves outwardly to the open position (FIG. 2). A
recess surface 40e (FIGS. 1, 4 and 5) is provided outwardly of the
rail engaging surfaces 40d so that when the ram R is in the closed
position (FIG. 1), the ram R is supported in the bore of the body
B, as will be more fully explained rather than having any contact
between the recess surface 40e and the rails 50. It should be noted
that the recess surface 40e extends inwardly to a shoulder 40f
which is between the recess surface 40e and the rail engaging
surface 40d. The distance from the inner ends 50c (FIG. 1) of the
guide rails 50 to the shoulder 40f is a predetermined distance
which determines the amount of outward travel of the ram R before
lifting of the ram R occurs as a result of the riding up of the
rail engaging surfaces 40d on the rails 50.
To prevent rolling and yawing of the ram R during its travel, the
rails 50 have substantially vertical or upright surfaces 50d which
engage inner guide surfaces 40g (FIGS. 4 and 5). Also, as
explained, the connecting button 26 is prevented from rotating
about its longitudinal central axis by the engagement of the wall
of the slot 26a with the pin 30a (FIGS. 1, 4 and 5).
To permit the vertical movement of the ram R from the position
shown in FIG. 4 to the position shown in FIG. 5 while still
maintaining full contact between the ram R and the wall of the ram
opening 11 so as to prevent heeling or pitching of the ram R, the
wall of the ram bore 11 is formed in a special manner as
hereinafter described. Thus, the wall of the ram opening 11 is
formed with lower curved sections 11a which are formed with a
radius from the center line 47 which is the same radius as the
radius of the ram curved side surfaces 40c formed from its center
line 45. Thus, in the position shown in FIG. 4, the external side
surfaces 40c of the ram R are coincidental and fully contact the
lower curved sections 11a of the wall of the ram bore 11. This is
the position of the ram R when the ram R is in the closed position
of FIG. 1 and when there is a pressure or force downwardly acting
on the ram due to the weight of the pipe engaged by the ram seal 41
or pressure from fluid above the ram R.
In the event the rams R are in the closed position of FIG. 1 and
the fluid pressure below the rams R exceeds the pressure thereabove
so that there is a resultant upward force acting on the rams R,
each ram is then urged upwardly so that the center line 45 of the
ram R shifts upwardly to a position corresponding closely to the
position shown in FIG. 5, except of course the ram R is in the
closed position at that time rather than the open position of FIG.
5, and in such closed position, the external end surfaces 40c
engage upper curved wall sections 11b. The upper curved wall
sections 11b are formed with the same radius as the ram end
surfaces 40c, but on a center line 46 which is spaced above the
center line 47. The center point for the radius of curvature of
each of the upper curved wall sections 11b is on the center line 46
(FIG. 4) which is spaced above the center line 45 when the ram R is
in the lower seated position of FIG. 4. When the ram R is raised
upwardly as shown in FIG. 5, then the center line 45 of the ram R
becomes coincidental with the center line 46. The center point for
the radius of curvature of each of the lower curved wall sections
is on the center line 47 in FIG. 5 which is below the center line
45 of the ram R when it is in the raised position of FIG. 5, but
which is coincidental therewith when the ram R is in the lower
position of FIG. 4. The distance between the lines 46 and 47
represents a spacing between the sections 11a and 11b on each side
thereof which is the distance of movement of the ram R from its
lower position of FIG. 4 to its upper position of FIG. 5 and vice
versa. It can thus be seen by comparing FIGS. 4 and 5 that the ram
R remains in full engagement with a portion of the wall of the ram
opening 11 in the body B at all times and heeling or pitching of
the ram R is prevented because of such contact.
It should also be noted that the ram R is in the position of FIG. 5
after the rail engaging surfaces 40d have been moved outwardly and
into engagement with the rail surfaces 50b of the rails 50. Since
each of the rails 50 extends as a single surface 50b throughout the
full length of travel of each ram R, there is uniform support of
each ram R throughout its travel on such rails 50 rather than on
the walls of the ram opening 11 of the body B. It should also be
pointed out that the ram opening 11 has an enlarged upper portion
11c which is preferably in alignment with the upper surface 12a of
the ram cavity 12 so that after the ram R has moved outwardly so as
to locate the ram seal or packing 44 to the left of the surface
11d, there is substantially no contact between the ram R and the
body B or the head H. Therefore, there is a minimum of frictional
resistance to the movement of the ram R as it moves outwardly on
the rails 50.
A pair of wipers 60 formed of rubber or the like, and preferably
formed integrally with the rubber of the ram seal 41, are disposed
for wiping engagement with the lower curved wall sections 11a so as
to facilitate a re-seating of the ram R when it is returned from
the open position to the closed position. Additional wipers 63 are
preferably provided in conjunction with the seal 44 (FIG. 3) and
such wipers 63 serve to wipe the wall surfaces 11b and 11d to
assure proper seating of the seal 44 with such surfaces upon a
return of the ram R from the open position to the closed position.
The wipers 63 are preferably formed of rubber or any other suitable
material which is softer than steel and is harder than the rubber
of the seal 44. Additionally, anti-extrusion strips 65 formed of
hard rubber or other suitable material which is harder than the
rubber of seal 44, may be positioned at the upper corner edges of
the seal 44 to facilitate the sealing action by such seal 44.
However, if the wipers 63 are utilized, the extrusion strips 65 may
be omitted.
The operation or use of the blowout preventer A of this invention
is believed to be apparent from the foregoing description. It will
be understood that FIGS. 1 and 2 illustrate only one-half of the
normal blowout preventer, with the other half being a mirror image
thereof, as is well known. The body B is of course mounted in a
casing or well pipe so that the longitudinal opening 10 of the body
B is aligned with and forms a continuation of the opening through
the well pipe or casing above and below the body B. The rams R may
be blind rams which completely seal off the opening 10 when they
are both in contact with each other at the closed position, or they
may be of the type which is adapted to seal around the pipe or a
wire line in the closed position. The illustrated ram seal 41 is of
the blind ram type having a flat inner surface 41a, which surface
would be curved to accommodate a pipe if such were not a blind ram,
as is well understood by those skilled in the art.
The head or bonnet H may be either of the swinging type which
swings in an arcuate path as it moves away from the body B, or it
may move in essentially a straight line path, both forms of which
are well known in the art. In either event, the support rails 50
are connected with or are formed integrally with the bonnet or head
H so that they move with such bonnet or head H. The rails 50 are
not joined to the body B but are positioned thereabove.
Under normal operating conditions with the rams R in the closed
position shown in FIG. 1, the curved side surfaces 40c rest upon
the lower curved wall sections 11a (FIG. 4). Should the pressure
below the ram R act to exert an upward force thereon which would
otherwise cause a heeling or pitching of the rams R, such heeling
is prevented because the rams R move upwardly so that the surfaces
40c fully contact the upper wall sections 11b . At this point, it
should be noted that FIG. 5 not only illustrates the apparatus in
the open position of FIG. 2, but it also accurately shows the
position of the apparatus when the ram R is in the closed position
of FIG. 1 with upward pressure urging it upwardly so that the
surfaces 40c engage the surfaces 11b. Thus, the blowout preventer A
has an automatic anti-heeling action.
When the rams R are moved by the power moving means C from the
closed position of FIG. 1 outwardly towards the open position of
FIG. 2, the rams R are moved upwardly by the engagement of each
surface 40d with each corresponding rail surface 50b after the rams
R have moved a predetermined outward distance as determined by the
distance between the ends 50c and the shoulders 40f as previously
explained. Thus, continued outward movement of each ram R is
accomplished with the ram supported only on the rails 50 as that
there is uniform spaced support with the weight of the ram R being
entirely on the rails rather than on any of the wall portion of the
body B or on the wall portion of the bonnet H.
Also, as previously explained, the rams R are prevented from
rolling and yawing by reason of the engagement of the surfaces 40g
of the rams and the surfaces 50d of the rails 50 (FIGS. 4 and
5).
It should be understood that the radius of curvature of the curved
wall sections 11a and 11b may be formed on the same center line, in
which case the upper and lower portions of the curved ram surface
40c would be formed on different center lines, so that the vertical
movements of the ram R as illustrated in FIGS. 4 and 5 is
accomplished. Additionally, the curved wall sections 11a and 11b
may be formed on different center lines such as lines 46 and 47,
and the upper and lower portions of the curved ram surface 40c may
also be formed on different center lines spaced a different
distance apart than the center lines for the radii of the curved
wall sections, so long as the vertical movements of the ram R as
illustrated in FIGS. 4 and 5 are accomplished while still obtaining
full engagement between the ram R and the wall of the body in both
the upper and lower positions.
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.
* * * * *