Swinging Blowout Preventer Head With Fluid Connector

Abstract

A swinging blowout preventer head with fluid connector wherein the swinging head is pivotally connected to a blowout preventer body so that a hydraulic fluid system to the ram cylinder mounted with the head remains sealed off at all times, including during the swinging of the head to and from its open and closed positions. Such fluid connector is non-load bearing, and preferably is capable of lateral movement as well as arcuate movement to assure sealing abutment between the body and the swinging head in the closed position while still confining the hydraulic fluid in the fluid system.

Description

SUMMARY OF THE INVENTION

The field of this invention is blowout preventers having swing heads.

Examples of blowout preventers having swinging heads are those shown in U.S. Pat. Nos. 2,942,616 and 2,946,550. In U.S. Pat. No. 2,942,616, the hydraulic lines are opened when each head is swung to its open position so that all or part of the fluid is lost each time the head is opened. In U.S. Pat. No. 2,946,550, the hydraulic fluid flows through the load bearing hinges so that the load on the hinges causes wear on the seals for the fluid pressure with resultant leakage of the hydraulic fluid from the system.

SUMMARY OF THE INVENTION

The present invention relates to a swinging blowout preventer head with a fluid connector which solves the problems of the prior art so that it can be moved to and from its open and closed positions without losing the hydraulic fluid used for operating the ram, and which has seals which are non-load bearing so that wear thereon is minimized. The heads are arcuately and laterally movable relative to the preventer body in the preferred embodiment so that each head may approach the body in a straight line rather than being confined to the arc defined by the hinge means to assure sealing abutment between the swinging head and the preventer body without strain on the hinge means, and with the fluid connector so constructed that it maintains the fluid flow passages sealed off during such movements. Preferably, the center line of the hinges or pivots for each swinging head is in a plane which is offset relative to the plane of the body-head interface so as to provide the shortest preventer with swinging heads.

BRIEF DESCRIPTION OF THE DRAWING

FIG. 1 is an elevation of one form of the blowout preventer of this invention;

FIG. 2 is a plan view of the blowout preventer of FIG. 1, with one of the heads in the closed position and the other of the heads in the open position, and with a portion of the head in the open position being shown in section;

FIG. 3 is a view taken on line 3--3 of FIG. 2 and it illustrates in particular the upper hinge assembly and the flexible fluid connector for each of the swinging heads of the present invention;

FIG. 4 is a view taken on line 4--4 of FIG. 3 to illustrate further details of the hinge means and the flexible fluid connector for each of the swinging heads; and

FIG. 5 is a view taken on line 5--5 to illustrate in particular the offset hinge construction which is preferably used.

DESCRIPTION OF THE PREFERRED EMBODIMENT

In the drawings, the letter A designates generally the blowout preventer of this invention which has a blowout preventer body B, with at least one, and preferably two swinging heads or bonnets H-1 and H-2 connected to the body B for swinging movements to and from closed and open positions, as will be explained in detail. In FIG. 2, the head H-2 is illustrated in the closed position while the head H-1 is illustrated in the open position. The heads H-1 and H-2 have blowout preventer rams R-1 and R-2, respectively, mounted therewith for movements to and from a ram-closed position and a ram-open position, as will be more fully explained. Hydraulic fluid or other fluid under pressure is supplied to cylinders C-1 and C-2 with the heads H-1 and H-2, respectively, for controlling the movements of the rams R-1 and R-2, with such fluid being directed through flexible fluid connectors F-1 and F-2, which will be described in detail hereinafter.

Considering the invention more in detail, the blowout preventer body B is of any conventional construction for receiving one or a pair of swinging heads and it includes a central longitudinal opening 10 through which pipe may pass when the rams R-1 and R-2 are in the open or retracted position. Also, the body B includes a pair of side openings 11, each of which is adapted to receive one of the rams R-1 and R-2 (FIG. 2) as each of such rams moves to and from the closed position, which is the position shown for the ram R-2 in FIG. 2. It will be understood that the body B is connected in a wellhead above a pipe string (not shown) by upper and lower studded flanges 14 on the body B having openings 12 in which studs (not shown) are conventionally positioned. Thus, the bore of the pipe string is longitudinally aligned with the vertical or longitudinal opening 10 in the body B, so that when the heads H-1 and H-2 are in their closed position, as illustrated for the head H-2 in FIG. 2, and the rams R-1 and R-2 are in their open position, the full opening of the longitudinal bore or opening 10 in the body B is provided so that the rams do not obstruct or interfere with the movement of well pipe or tools therethrough. The rams R-1 and R-2 may be of any conventional construction and may either be blind rams which contact each other to completely close off the opening 10 when no pipe or other object is disposed in the longitudinal bore 10, or they may be pipe rams which seal around a well pipe which is disposed in the bore 10 to prevent fluid flow around the annulus surrounding such pipe, as is well understood.

The ram R-1 is connected to a piston 15 by a piston rod 16 so that fluid pressure within the cylinder C-1 acting on the piston 15 transmits its movements through the rod 16 to the ram R-1 in the known manner. Suitable O-rings or other seals 17 engage the rod 16 to confine fluid pressure within the cylinder C-1. The ram R-2 is similarly connected to a piston 15 through a piston rod 16, with the piston 15 being in the cylinder C-2.

The cylinders C-1 and C-2 are secured to their heads H-1 and H-2, respectively by any suitable securing means such as a plurality of bolts 18, in the known manner, so that the cylinders C-1 and C-2 move with their heads or bonnets H-1 and H-2 in their movements relative to the body B.

When the heads H-1 and H-2 are in the closed position, they are secured to the body B by any suitable securing means such as bolts 20, in the known manner.

Each of the heads H-1 and H-2, and the parts connected with each of such heads, is pivotally mounted on the body B by hinge means P-1 and P-2, respectively. As will be more evident hereinafter, the hinge means P-1 takes substantially all of the load of the head H-1 and the parts therewith so that the fluid connector F-1 is a non-load bearing structure. Similarly, the hinge means P-2 takes substantially all of the load of the head H-2 and the parts therewith so that the flexible fluid connector F-2 is a non-load bearing structure. The details of the upper hinge assembly of the hinge means P-2 is illustrated in detail in FIGS. 3-5, and such structure is preferably identical to that used for the upper hinge assembly of the hinge means P-1 as well as the lower hinge assemblies of the hinge means P-2 and P-1. Therefore, the detailed description of the hinge assembly illustrated in FIGS. 3-5 relates to each of the hinge assemblies in the two hinge means P-1 and P-2.

Referring now to FIGS. 3-5 in particular, the upper hinge assembly of the hinge means P-2 includes a fixed hinge member 25 which is in the form of a tongue of generally cylindrical shape with a central opening 25a through which a hinge pin 27 extends, as will be more fully explained. The fixed hinge member 25 has a base or flange 25b projecting from one portion thereof which is adapted to be welded or otherwise secured to the body B. A movable hinge member 30 which is generally in the shape of a clevis with an opening 30a to receive the fixed member or tongue 25, forms the other part of the hinge assembly and it is secured to the head or bonnet H-1 or H-2. The movable hinge member 30 has aligned openings 30b therethrough, through which the hinge pin 27 extends when such openings 30b are aligned with the opening 25a in the member 25. Washers 31 are preferably disposed above and below the member 25, with suitable O-rings 32 surrounding the washer (FIGS. 3 and 4).

The hinge pin 27 is preferably in the form of a bolt having a head 27a with a washer and O-ring 28 between the head and the upper surface of the movable hinge member 30. The hinge pin or bolt 27 has threads 27b for receiving a nut 29 and a sealing type lock nut 33, which nuts may be one-piece, and with a washer and O-ring 34 between the nut 29 and the lower surface of the movable member 30.

To provide for lateral movement of the hinge members 25 and 30 relative to each other, and particularly the movement of the hinge member 30 relative to the fixed member 25 in the form of the invention illustrated, an annular space 40 is provided between the bore 25a of the fixed member 25 and the portion of the hinge pin 27 which is within such bore. Preferably as illustrated, the diameter of the hinge pin 27 is reduced at 27c to provide such annular space 40 and to permit the relative lateral movement of the hinge member 30 relative to the hinge member 25 so that the head can move in a substantially straight line, i.e., both arcuately and laterally, to and from the open and closed positions.

A suitable opening 25c is provided for receiving a grease fitting 38 of any conventional construction so as to provide for lubricating the hinge at the hinge pin and the adjacent parts. The O-rings 32 serve to assist in confining the grease or other lubricant within the annular space 40.

The hinge means P-1 and P-2 are each disposed in a plane which is different from the plane of the interface between the head H-1 or the head H-2 and the body B, such as represented at the line 40 for such interface. Because of such offset relationship in which the plane of the hinge pins 27 is positioned relative to the plane of the head-body interface 40', the head or bonnet H-1 or H-2 has the shortest possible length, which can best be determined by trial and error location of such planes. Also, because of the lateral and arcuate movements of each of the heads relative to the body B during the closing movement thereof, there is an assurance of an abutment between the body B and the head in the final closed position.

The details of the connector F-2 are illustrated in FIGS. 3 and 4, and the following description with respect to such connector F-2 will likewise apply to the fluid connector F-1, and therefore, corresponding parts will bear the same letters and/or numeral designations for both of the connectors F-1 and F-2. Referring now to FIGS. 3 and 4, the fluid connector F-2 includes a fixed connector member or yoke 50 which is preferably secured to the body B by means of a plurality of stud bolts 51 which are threaded into the body B at threaded openings 52 (FIG. 3). The fixed connector member 50 is formed with a pocket 50a which is adapted to receive a connector arm of a movable connector member 55 which is secured to the head H-2 by any suitable means such as a plurality of stud bolts 56 (FIG. 4).

The fixed connector 50 has an inlet passage 50b which communicates with a lateral passage 50c in the connector member 50, and also with a fluid passage 57 in the body B. An inlet tube 60 is connected from any suitable source of hydraulic fluid under pressure (not shown) so as to supply hydraulic fluid to the system. A similar lower inlet flow passage 50d is provided in the fixed connector member 50 in communication with a lateral fluid flow passage 50e in the member 50 and with a fluid passage 61 in the body B. A tube 62 is connected to the passage 50d for supplying hydraulic fluid under pressure to the inlet passage 50d. As will be explained, the lines 60 and 62 are alternately used for directing fluid under pressure and for returning fluid under pressure, depending upon the direction in which the rams R-1 and R-2 are to be moved, as will be well understood by those skilled in the art.

Suitable O-rings or other seals 63 are provided around the passages 50b and 50d, between the fixed connector member 50 and the body B to prevent leakage of the hydraulic fluid at such areas.

The movable connector member 55 has lateral flow passages 55a and 55b which are in fluid communication with lateral passages 50c and 50e, respectively, and are sealed off by a suitable seal means such as O-rings 65. The fluid passage 55a in the movable connector member 55 is in fluid communication with a fluid passage 70 formed in the head H-1 or H-2. Such fluid passage 70 directs the hydraulic fluid to the area of the cylinder C-1 or C-2 which is inwardly of the piston 15 (FIG. 2). The fluid passage 55b in the connector 55 is in fluid communication with a fluid passage 71 which is disposed below the passage 70 (not visible in FIG. 2) and which is also in communication with a continuation of such fluid passage 71a in the cylinder C-1 or C-2 for introducing the hydraulic fluid under pressure to the area of the piston 15 outwardly thereof.

The fluid passages in the fixed connectors 50 of the fluid connectors F-1 and F-2 are preferably interconnected through the fluid passages 57 and 61 preferably formed in the body B (FIGS. 2 and 3), although each of the fluid connectors F-1 and F-2 may be supplied with hydraulic fluid under pressure separately without the use of interconnecting passages such as the passages 57 and 61, and therefore the rams R-1 and R-2 may be controlled separately, if so desired.

To permit the lateral movement of the movable connector member 55 relative to the fixed connector member 50 in each of the flexible fluid connectors F-1 and F-2, without losing the effectiveness of the seal provided by the O-ring 65 between the connector members 50 and 55, the diameter or size of the passage 50c is smaller than the diameter or size of the opening of the fluid passage 55a. Likewise, the size or diameter of the opening of the fluid passage 50e is smaller than the diameter or size of the opening of the passage 55b. Such relationship may be reversed, and it will be appreciated that in some instances the diameters of such adjacent openings 50c, 55a and 50e, 55b may be the same, providing that the seal by the O-rings 65 is maintained even during the relative lateral movement of the connector member 55 with respect to the fixed member 50.

Since all, or substantially all, of the load or weight of the heads H-1 and H-2 are carried by their hinge means P-1 and P-2, respectively, particularly when they are in the open position as illustrated by the head H-1 in FIG. 2, there is no weight or load on the seals 65 or any of the other portions of the connector members 50 and 55, so that the wear on the contacting parts, and particularly the seal 65 is at a minimum, thereby increasing the life of such seals and the contacting surfaces between the connector members 50 and 55. Also, regardless of the position of either head, H-1 or H-2, the fluid system remains sealed so that the rams can be actuated whether the heads are in the open position or the closed position. This is important because when the heads are moved from the closed position to the open position, the rams are in the retracted position with the rams essentially enclosed within the heads, but after the heads have been moved to the opened position such as illustrated for the head H-1 in FIG. 2, then the rams are moved to the inward position such as illustrated in FIG. 2 for the ram R-1 to facilitate the removal of the ram for replacement or repair.

In the operation or use of the blowout preventer A of this invention, each of the heads H-1 and H-2 is provided with a hinge means P-1 and P-2, respectively for taking the load or weight of the heads during their movements and when in the open position in particular. The location of the hinge pins 27 for each of the hinge means P-1 and P-2 in a position inwardly of the interface 40' between the body and the head provides for the shortest possible length of the overall blowout preventer because the arcuate path of movement of the heads to and from the closed position is minimized. Furthermore, the heads may be moved in a substantially straight line because of the lateral shifting permitted at the hinge pins between the heads and the body B. By providing the flexible fluid connectors F-1 and F-2 entirely independently of the hinge means P-1 and P-2, respectively, the fluid system remains in sealed and operative condition during the pivotal movements of the heads H-1 and H-2, even though there is the lateral play or shifting permitted at the hinge means P-1 and P-2. Therefore, the separate fluid connectors F-1 and F-2 make the lateral shifting of the hinge means P-1 and P-2 possible. It should be noted that the axis of rotation of the connector members 50 and 55 is preferably in longitudinal or vertical alignment with the axis of rotation of the hinge assemblies through the hinge pins 27 thereabove and therebelow for both of the heads H-1 and H-2.

Although the hinge pins 27 have been shown with a reduced diameter portion 27c, it should be understood that each of the pivot or hinge pins 27 may have the same external diameter throughout its length, and the annular space 40 may be provided by having the diameter of the longitudinal bore or passage 25a greater than that of the longitudinal openings 30b so as to permit the lateral relative movement between the hinge members 30 and 25.

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.

Claims

I claim:

1. A blowout preventer, comprising:

a blowout preventer body having a longitudinal opening through which a pipe string is adapted to extend;

said body also having at least one side opening in communication with said longitudinal opening;

a preventer head disposed on one side of said body for movement relative thereto from a closed position in contact with said body to an open position wherein said side opening is exposed;

a cylinder mounted on said head for movement therewith;

a ram slidably mounted in said head for movement relative to said head from a ram-closing position to a ram-open position, and having a ram piston therewith disposed in said cylinder for effecting the movements of said ram relative to said head;

hinge means pivotally connecting said head to said body for pivotal movements of said head to and from its open and closed position;

fluid passage means in said head and cylinder for directing fluid pressure to said cylinder for operating said piston to move said ram to and from its ram-closed and its open positions; and

fluid connector means for directing fluid pressure to said fluid passage means;

said fluid connector means including:

a fixed connector member mounted on said body;

a movable connector member mounted on said head; and

fluid passages through said fixed and movable connector members in fluid communication with said fluid passage means in said head at all positions of said head relative to said body.

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

said hinge means support substantially all of the load of said head and the parts therewith, whereby said fluid connector members are non-loading bearing members.

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

seal means between said fixed and movable connector members for sealing therebetween at the interconnection between said fluid passages in said members.

4. The structure set forth in claim 1, wherein said hinge means includes:

a fixed hinge member secured to said body;

a movable hinge member secured to said head; and

means connecting said hinge members together for arcuate and lateral movement of said movable hinge member to assure contact between said head and said body at their interface when said head is in the closed position.

5. The structure set forth in claim 4, wherein said means connecting said hinge members together for arcuate and lateral movement includes:

a hinge pin opening in each of said fixed and movable hinge members, aligned with each other;

a hinge pin extending through said aligned openings; and

said opening through said fixed hinge member being larger than the diameter of the portion of said hinge pin disposed within said opening for permitting lateral movement of said pin and movable hinge member therewith relative to said fixed hinge member.

6. The structure set forth in claim 4, wherein:

said movable connector member is rotatable and laterally movable relative to said fixed connector member within the limits of the lateral movement of said movable hinge member relative to said fixed hinge member.

7. The structure set forth in claim 6, including:

seal means between said fixed and movable connector members for sealing therebetween at the interconnection between said fluid passages in said members during the rotational and lateral movement of said movable connector member.

8. The structure set forth in claim 7, wherein:

the size of the openings in adjacent fluid passages in said movable and fixed connector members are both smaller than the diameter of said seal means surrounding said openings so that the seal between the connector members is maintained during lateral movement of said movable connector member relative to said fixed connector member.

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

said fixed connector member has a central pocket, with at least one of said fluid passages therein opening into said pocket;

said movable connector member has a connector arm rotatably mounted in said pocket and having at least one of said fluid passages therein opening into said fluid passage from said fixed connector member to establish fluid communication therebetween.

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

an annular seal between said connector members and surrounding the adjacent openings of said fluid passages in said connector members.

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

said fixed connector member has a central pocket, with a plurality of said fluid passages therein opening into said pocket;

said movable connector member has a connector arm rotatably mounted in said pocket and having a plurality of said fluid passages therein, each fluid passage in said fixed connector member opening into a fluid passage in said movable connector member.