Title:
Blowout preventer ram
United States Patent 2090206


Abstract:
My invention relates to blowout preventers, and more particularly to the rams which are employed in blowout preventers to engage about the pipe or drill stem and form a seal therewith. Blowout preventers of this general character are well known in the art. Two opposing rams or pistons are mounted...



Inventors:
King, Walter E.
Application Number:
US66694833A
Publication Date:
08/17/1937
Filing Date:
04/20/1933
Assignee:
King, Walter E.
Primary Class:
International Classes:
E21B33/06
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Description:

My invention relates to blowout preventers, and more particularly to the rams which are employed in blowout preventers to engage about the pipe or drill stem and form a seal therewith. Blowout preventers of this general character are well known in the art. Two opposing rams or pistons are mounted on the well casing so as to be moved toward the pipe or drill stem extending into the casing and close off the escape of fluid between the interior pipe or drill stem and the casing. The forward faces of the rams are formed with semi-cylindrical recesses to fit about the pipe or drill stem. It has been found, however, that occasionally the inner pipe or drill stem will not be in concentric position with the casing, but will be fallen over to one side thereof, so that when the rams are moved together, the pipe or drill stem will not be engaged within the recesses, but will be to one side thereof and the rams will contact with the pipe without closing and forming a seal therewith.

To avoid accidents of this kind, it is an object of my invention to provide means at each side of the semi-cylindrical recess in each ram which will tend to engage the pipe and move it toward the center where it will be received within the recess in the rams.

I desire to form, upon the forward end of each ram, an inclined projection which, when it engages the inner pipe will, because of its inclined face, tend to move the pipe toward a middle or concentric position in the casing.

The general object of the invention is to provide blowout preventer rams with means which tend to center the inner pipe so that the rams may properly engage therewith and seal off the space around said pipe.

In the drawing herewith, Fig. 1 is a top plan view of an ordinary type of blowout preventer 10 showing my improved rams therein.

Fig. 2 is a side elevation of the two cooperating rams removed from the housing of the blowout preventer.

Fig. 3 is a perspective view of the two rams 15 shown separated from each other to expose the mating surfaces of the rams.

Fig. 4 is a longitudinal section through one of the rams taken approximately on the line --4 of Fig. 3.

i0 The type of blowout preventer In which my rams are to be used may vary somewhat in structure, but as such structures are old and well known in the art, I have shown the same somewhat diagrammatically.

5 In Fig. 1 the housing I of the blowout preventer is shown as mounted on the body 2 which has a vertical passage therethrough for the drill stem or tube 3. The housing I is cylindrical in shape and is adapted to receive the two opposed rams 4 operating therein. In the present form a pressure operated blowout preventer is shown.

There is a cylinder 5 beyond the housing I for each ram, and connections are shown at 6 whereby pressure fluid may be introduced to operate the adjacent ram. The ram is also provided with a stem or shaft 7 which projects beyond the housing and is squared at its end 8 to receive a wrench or hand wheel whereby the shaft may be screwed inwardly or outwardly to engage the ram and hold the same in fixed position. The particular construction of the rams forms the improvement in the present invention. Referring to Figs. 2, 3 and 4, the structure of said rams will be more clearly understood. Each ram 4 is cylindrical on its outer periphery to fit within the cylindrical casing or housing I. Each ram forms a fluid tight fit within the housing by means of a strip of packing material 9, which extends around the outer end of the ram and longitudinally along the horizontal face thereof to the forward end of said ram, and it there extends across the face of the ram and then rearwardly, as shown. This arrangement of packing on the ram is also old and well known.

The present invention lies largely in the manner in which the forward mating faces of the two rams are constructed. I form the said faces to interfit, but on each ram at the upper side, the forward face at one side is projected forwardly from the ram as shown at 10 and the forward face of the projection is inclined rearwardly from the outer edge so as to provide a cam face II which may engage the pipe when the pipe is out of its normal central position.

Also, on the lower side of each ram there is a forwardly projecting portion 12. This will be understood particularly from Fig. 3 where the upper projection 10 is at one side of the semi-cylindrical recess 13 and the lower projection 12 is on the opposite side of the central semi-cylindrical recess. The lower projection 12 Is also formed with a forward cam surface 14 which is directed toward the recess 13 so as to tend to move the pipe toward the recess.

Between the two projections 10 and 12 the forward face of each ram is flattened off at 15 to engage evenly with the forward face of the opposite ram and the sealing strip 9 is extended diametrically across the flattened area 15. It will be understood from the drawing that the 2 9,090 faces of the two rams are recessed opposite the projection on the opposite ram so that when the two rams are moved together they will interfit as shown best n Fig. 2.

Each ram may be formed for engagement with the operating device in any preferred manner.

I have shown in Fig. 4 that the ram 4 is made of hollow material, the outer end being provided with a recess at 16 to receive a plate upon the end of the operating stem or shaft which connects it with the piston. There are a series of openings 17 in the end of the piston whereby the same may be connected with the operating means, but as this forms no part of the present invention it is not more particularly disclosed.

Each of the pistons or xams has a key-way I thereon to receive a pin or key in the wall of the housing to hold the ram in aligned position and prevent any rotation of the same in the cylinder which would tend to move the same from aligned position.

In the operation of the device, the rams are normally in retracted position away from the central opening through the preventer. When danger of a blowout occurs, however, the rams are moved forwardly to engage about the pipe 3. If the pipe is at one side of the center somewhat as shown in Fig. 1, the forward inclined or cammed surfaces I upon the rams will contact with the pipe and tend to direct it inwardly toward the center. The sectional view of the ram shown in Fig. 4 will tend to more clearly illustrate this point. The pipe will, therefore, be pushed toward the center as the rams are closed and will be engaged within the semicylindrical recess 13 in each of the rams whereby a seal can be formed about the pipe closing off the passage of the fluid upwardly outside of the pipe.

By the use of this invention, I am sure that there will be no accidental failure of the rams to center the pipe within the recess 13 where a proper closure can be made. If the pipe should be out of its normal position concentric with the casing it will be immediately forced into the central recess where a sealing engagement therewith may be made as the rams are forced tightly together in the usual manner.

What I claim" as new is: 1. In a blowout preventer, a housing having a central vertical opening to receive a pipe, two opposed chambers in said housing, rams in said chambers movable toward and away from sealing engagement with said pipe and each other, packing material on the forward meeting faces of said rams, and means on the meeting faces of said rams projecting forwardly beyond said packing, to engage said pipe and move it toward a central position in said housing and also acting to protect said packing.

2. In a blowout preventer, a housing having a central opening to receive a pipe, opposed rams in said housing movable toward and away from said opening, the meeting surfaces of said rams having semi-cylindrical recesses to fit about said pipe, packing material on the forward meeting faces of said rams, and means projecting forwardly beyond said packing, to move said pipe toward said recesses as said rams are closed toward each other and also acting to protect said packing.

3. In a blowout preventer, a housing having a central opening to receive a pipe, opposed rams in said housing movable toward and away from said opening, the meeting surfaces of said ranm, ,206 having semi-cylindrical recesses to fit about said pipe, packing on the forward faces of said rams and cam-shaped projections on said rams at each side of said recesses to engage said pipe and spaced from said packing, to force said pipe Into said recesses as said rams are moved toward each other.

4. In a blowout preventer, a housing having a central vertical opening to receive a pipe therein, rams in said housing, movable relative to 11 each other to and from end contact with each other and having recesses in their meeting ends to engage about said pipe, sealing means on said meeting ends, and projections on the meeting faces of said rams at each side of said recesses 1 shaped to interfit, said projections being shaped to engage said pipe and center the same in said recesses.

5. In a blowout preventer, a housing having a vertical opening adapted to receive a pipe, op- 2 posed rams movable transversely of said opening into end abutting contact with each other and with the pipe, the meeting ends having recesses to fit about the pipe, packing means on the meeting faces of said rams, each ram having upper and lower projections, one on each side of said recesses, said projections being shaped to center said pipe and protect said packing means.

6. In a blowout preventer, a housing having a central opening to receive a pipe, opposed rams in said housing, movable toward and away from said opening, the meeting faces of said rams having semi-cylindrical recesses to fit about said pipe, and upper and lower cam shaped projections on each of said rams to engage said pipe and move it toward said recesses, the upper projection being on the opposite side of said recess from said lower projection, said projections engaging said pipe in response to the forward movement of said rams.

7. In a blowout preventer, a housing having a central opening to receive a pipe, opposed rams in said housing movable toward and away from said opening, the meeting surfaces of said rams having semi-cylindrical recesses to fit about said pipe, a packing strip transversely of said recess on each ram, and cam-shaped projections on said rams above and below said packing strip adapted to contact with said pipe and center It in said recesses in response to the forward movement of said rams, said projections acting to prevent contact of said pipe with said strip on each side of said recess.

8. In a blowout preventer having a housing provided with a vertical opening adapted to receive a pipe, opposed rams movable transversely of the opening into abutting relation with each other and with the pipe, the abutting parts of the rams having recesses to fit about the pipe, packing means carried by the rams at their meeting faces, each ram having upper and lower projections, one on each side of said recesses, said projections being shaped to center the pipe.

9. In a blowout preventer having a housing provided with a vertical opening to receive a pipe, oppositely disposed rams movable transversely of the opening into abutting relation and whose abutting ends are shaped to surround the pipe, packing means on said ends, said abutting ends including projecting guides shaped to engage and Scenter the pipe in said opening upon movement of the rams about the pipe.

WALTER E. KING.