Title:
BLOWOUT PREVENTER WITH RAM SUPPORT AND GUIDE MEANS
United States Patent 3744749


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 R
Application Number:
05/144556
Publication Date:
07/10/1973
Filing Date:
05/18/1971
Assignee:
HYDRIL CO,US
Primary Class:
Other Classes:
277/325
International Classes:
E21B33/06; (IPC1-7): E21B33/06
Field of Search:
251/1 277
View Patent Images:
US Patent References:
3642290COMPOSITE ROD WIPER1972-02-15Millsap
2942616Hinged cap, cellar production gate1960-06-28Wilde
2934148Multiple zone well completion1960-04-26Allaire
2749078Well blowout preventer1956-06-05Losey
2146470Valve1939-02-07Grantham et al.
1960592Blow-out preventer1934-05-29Nixon
1819875Safety casing head for oil wells1931-08-18Cunningham



Primary Examiner:
Schwadron, Martin P.
Assistant Examiner:
Gerard, Richard
Claims:
I claim

1. A blowout preventer, comprising:

2. The structure set forth in claim 1, including:

3. The structure set forth in claim 1, wherein said ram support means includes:

4. The structure set forth in claim 3, including:

5. The structure set forth in claim 3, wherein:

6. The structure set forth in claim 5, wherein:

7. The structure set forth in claim 1, including:

8. The structure set forth in claim 1, wherein:

9. The structure set forth in claim 8, wherein:

10. The structure set forth in claim 9, wherein:

11. The structure set forth in claim 1, including:

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.