Side retainer plate for variable bore ram packer for a ram type blowout preventer

Abstract

A variable bore ram packer including a ram body, a top seal and a packer member designed for use in a standard ram-type blowout preventer used in oil and gas drilling operations is disclosed. A side retainer plate is molded into the edges of the packer member. The side retainer plate includes a depending lip portion to minimize extrusion of the elastomeric material between the packer member and the guideways of the blowout preventer.

Description

BACKGROUND OF THE INVENTION

[0001] 1. Field of the Invention

[0002] This invention relates to a side retainer plate for use in variable bore ram packers for a ram-type blowout preventer used in oil and gas drilling operations. The side retainer plate is intended to contain rubber in the variable bore ram packers to prevent excessive rubber loss which can lead to premature wear. This allows the packer to operate within the ram guideways of the blowout preventer for a longer period of time without damaging the ram guideway and prevents pressurized well bore fluid leaking.

[0003] Ram-type blowout preventers are part of a pressure control system used in oil and gas drilling operations to control unexpected well bore pressure spikes or “kicks” as they are commonly referred to in the industry. The blowout preventer has a body with a vertical bore and a pair of laterally disposed opposing bonnet assemblies. Each bonnet assembly includes a piston which is laterally moveable within the bonnet assembly by pressurized hydraulic fluid. Replaceable sealing elements called “packers” are mounted within rams attached to the ends of the pistons which extend into the blowout preventer bore. When these pistons are moved to a closed position, commonly referred to as “closing the blowout preventer” or “closing the rams”, the vertical bore of the blowout preventer is sealed and the kick is contained. These packers are available in a variety of configurations designed to seal the blowout preventer bore when the opposing rams and pistons are moved to their closed position.

[0004] One type of ram with packer has ends designed to seal around pipe of a specific size in the blowout preventer bore when the blowout preventer is closed. Other rams with packers are configured to seal around a range of pipe sizes. It is the type designed to seal around a range of pipe sizes, called variable bore ram packers to which the present invention is directed. The ram packers form a pressure tight seal during a kick until the well bore pressure can be controlled. The well bore pressure can reach several thousand pounds per square inch during a kick. Each ram packer has a semicircular opening in its front face to form a seal around 1800 of the outer periphery of the pipe. When the rams are closed as described above, the opposing ram packers meet and seal the entire 360° periphery of the pipe. The novel side retainer plate of the present invention is designed for use in a variable bore ram packer and has a depending edge or lip to prevent excessive rubber loss of the side block seals of the ram packer which can lead to premature wear. This allows the packer to operate within the ram guideways of the blowout preventer for a longer period of time without damaging the ram guideway and prevents pressurized well bore fluid leaking

[0005] 2. Description of Related Art

[0006] The use of metal inserts in a conical-type blowout preventer is disclosed in U.S. Pat. No. 2,846,178 to B. S. Minor.

[0007] U.S. Pat. No. 3,897,038 to R. K. Le Rouax shows a ram type blowout preventer using metal inserts as an anti-extrusion means.

[0008] The use of metal inserts in an annular blowout preventer to control the stress level in the elastomeric packer unit is shown in U.S. Pat. No. 3,917,293 to G. E. Lewis et al.

[0009] U.S. Pat. No. 4,099,699 to H. Allen shows the use of irising metal inserts in an annular blowout preventer.

[0010] Another example of metal inserts in a variable bore blowout preventer in disclosed in U.S. Pat. No. 4,229,012 to B. C. Williams, III.

[0011] U.S. Pat. No. 4,444,404 to G. C. Parks, Jr. shows an example of a variable bore ram packer with interlocking anti-extrusion metal inserts.

[0012] Another example of a variable bore ram packer with interlocking anti-extrusion metal inserts is disclosed in U.S. Pat. No. 4,458,876 to G. R. Schaeper et al.

[0013] U.S. Pat. No. 4,550,895 to D. U. Shaffer shows an early version of a variable bore ram packer. This apparatus utilizes a plurality of annular segments embedded in the elastomeric rubber to aid in effectuating a seal.

[0014] U.S. Pat. No. 6,367,804 B1 to G. D. Watts discloses variable bore ram packer utilizing a pillar insert with top and bottom plates that are rotatable with respect to one another to allow sealing on taper tool joint connections.

SUMMARY OF THE INVENTION

[0015] The side retainer plate of the present invention is designed for use in a variable bore ram packer in a standard ram-type blowout preventer used in oil and gas drilling operations. The blowout preventer has a body with an axial bore, a pair of opposing bonnet assemblies and a pair of opposing rams laterally moveable within the bonnet assemblies by a pressurized fluid source to control flow of well fluids through the blowout preventer body axial bore. The variable bore ram packer includes a ram body, a top seal and a packer member. The packer member is molded of an elastomeric material having a central opening sized to fit closely about a tubular member when the blowout preventer is closed. The packer member includes a plurality of packer inserts molded within the elastomeric material surrounding the central opening of the elastomeric material. The packer member and the plurality of packer inserts are molded into a unitary structure allowing the plurality of packer inserts to move and seat against different diameter tubular members to prevent extrusion of the elastomeric material between the packer inserts and the tubular member.

[0016] The unitary structure includes a pair of side block seals molded integrally therewith. The side block seals have an upper and lower face with a side retainer plate of the present invention within each of the upper and lower faces. The side retainer plate includes a planar portion, positioned parallel to the upper and lower faces, and a depending outer portion that is molded below the surface of the side block seals to conform to the ram guideway of the blowout preventer.

[0017] The packer inserts include a top plate, a bottom plate and a central web positioned therebetween and integrally formed therewith. The top and bottom plates are a substantially triangular shape and each of the top and bottom plates includes a guide lip and a guide shoulder. The guide lips and guide shoulders of adjacent top plates and the guide lips and guide shoulders of adjacent bottom plates coact to provide an irising motion to the top and bottom plates as the top and bottom plates move and seat against different diameter tubular members. The simultaneous movement of the top and bottom plates of the insert allows the top and bottom plates to move and seat against the tubular member.

[0018] A principal object of the present invention is to provide a side retainer plate for use in a variable bore ram packer that minimizes rubber extrusion around the sides of the ram packer.

[0019] A further object of the present invention is to provide a side retainer plate for use in a variable bore ram packer that can maintain the rubber in the variable bore ram packer and minimize premature wear.

[0020] These with other objects and advantages of the present invention are pointed out with specificness in the claims annexed hereto and form a part of this disclosure. A full and complete understanding of the invention may be had by reference to the accompanying drawings and description of the preferred embodiments.

BRIEF DESCRIPTION OF THE DRAWINGS

[0021] These and other objects and advantages of the present invention are set forth below and further made clear by reference to the drawings, wherein:

[0022] FIG. 1 is a perspective view illustrating a cutaway section of a typical ram-type blowout preventer used in oil and gas drilling operations with the side retainer plate of the present invention in a variable bore ram packer shown installed within.

[0023] FIG. 2 is an exploded view of a variable bore ram packer with the side retainer plates of the present invention.

[0024] FIG. 3 is a sectional view, taken along lines 3-3 of FIG. 2, showing the relationship between the side retainer plates of the present invention and the packer pins.

[0025] FIG. 4 is a perspective view of a side retainer plate of the present invention.

DESCRIPTION OF THE PRESENTLY PREFERRED EMBODIMENT

[0026] With reference to the drawings, and particularly to FIG. 1, an isometric view of a ram type blowout preventer 10 used in oil and gas drilling operations is shown. The ram type blowout preventer 10 includes a body or housing 12 with a vertical bore 14 and laterally disposed ram guideways 16. Bonnet assemblies 18 are mounted to the body 12 with suitable securing means such as studs or bolts 20 and aligned with laterally disposed guideways 16. Each bonnet assembly 18 includes an actuation means 22, including a piston 24 and connecting rod 26. While only one guideway 16 and actuation means 22 is shown, it is understood by those of ordinary skill in the art that there is a pair of opposed guideways 16 and actuation means 22. Each connecting rod 26 is connected to a ram 28 which includes variable bore ram packer 30. Side retainer plates 32 of the present invention are positioned within variable bore ram packer 30. Actuation means 22 allows ram 28 and variable bore ram packer 30 to be reciprocated within guideways 16 or “opening and closing the rams” as it is referred to in the industry.

[0027] Variable bore ram packer 30 is shown in an exploded view in FIG. 2 to aid in understanding the relationship between the parts. Variable bore ram packer 30 includes packer member 34 of an elastomeric material with suitable rheological characteristics and packer inserts 36 molded into one unitary structure with packer inserts 36 arranged around a central opening 38 to form an insert array 40 that is sized to fit closely about a tubular member. Packer pins 42 are molded into variable bore ram packer 30 for connecting variable bore ram packer 30 to ram 28. Packer member 34 is molded to form side block seals 44 on its lateral edges. Ram 28 includes top seal 46 on its upper face. Top seal 46 and side block seals 44 combine to seal ram 28 in guideways 16 of ram type blowout preventer 10 in a manner well known to those of ordinary skill in the art. When rams 28 are closed around a tubular member disposed in bore 14 of ram type blowout preventer 10, packer members 34 seal around the tubular member.

[0028] Side block seals 44 have a curved outer surface 48 to conform to the shape of guideways 16 to allow reciprocation therein and aid in sealing. Side block seals 44 include upper face 50 and lower face 52 with side retainer plates 32 molded therein. As best seen in FIG. 4, side retainer plate 32 includes planar portion 54 and depending portion or lip 56. Planar portion 54 includes elongated pin slot 58 for engagement with packer pin 42 in a manner to be explained hereinafter. Depending portion or lip 56 is shaped to approximate the curvature of curved outer surface 48 and be molded therein as seen in FIG. 2. The shape and positioning of depending portion or lip 56 within side block seal 44 aids in preventing excessive rubber extrusion when side block seal 44 and variable bore ram packer 30 are in the closed position and subjected to well bore pressure or test pressure.

[0029] Referring to FIG. 3, the interaction of packer pins 42, wing retainer plates 32 and side block seal 44 is shown. Packer pins 42 include horizontal portion 60 and vertical portion 62 in the perpendicular orientation shown. Horizontal portion 60 includes slot 64 for engagement with pins 66 molded into top seal 46. Vertical portion 62 includes reduced diameter end segments 68 that engage elongated pin slots 58.

[0030] Referring back to FIG. 2, packer inserts 36 include top plate 70, bottom plate 72 and central web 74. Top plate 70 and bottom plate 72 are substantially triangular in shape with central web 74 positioned thereon. Central web 74 is integrally formed with top plate 70 and bottom plate 72 by suitable means as casting. Top plate 70 and bottom plate 72 are mirror images of one another and include guide lip 76 and guide shoulder 78 formed on top plate 70 and guide lip 80 and guide shoulder 82 formed on bottom plate 72. Thus, when packer inserts 36 are molded into packer member 32, guide lips 76 and guide shoulders 78 of adjacent top plates 70 overlap. Similarly, guide lips 80 and guide shoulders 82 of adjacent bottom plates 72 overlap. Thus, as seen in FIG. 2, the assemblies of top plates 70 and bottom plates 72 are arranged to form semi-circular steel arcs similar to that of an “iris” shutter of a camera that acts to prevent extrusion of the elastomeric material of packer member 32 in use.

[0031] The construction of my side retainer plate for use in a variable bore ram packer will be readily understood from the foregoing description and it will be seen that I have provided a side retainer plate for use in a variable bore ram packer that minimizes rubber extrusion around the sides of the ram packer. Furthermore, while the invention has been shown and described with respect to certain preferred embodiments, it is obvious that equivalent alterations and modifications will occur to others skilled in the art upon the reading and understanding of the specification. The present invention includes all such equivalent alterations and modifications, and is limited only by the scope of the appended claims.

Claims

1. A variable bore packer used in a ram-type blowout preventer for oil and gas drilling operations, comprising:

a packer member moveable within a ram guideway of a blowout preventer, said packer member molded of elastomeric material having a central opening sized to fit closely about a tubular member upon closure of said blowout preventer;

a plurality of packer inserts molded within said elastomeric material into a unitary structure to form an insert array to move and seat against different diameter tubular members to prevent extrusion of said elastomeric material between said packer inserts and the tubular member;

said unitary structure is molded to form a pair of side block seals integral with said packer member, said side block seals having an upper and lower face; and,

a pair of wing retainer plates molded within each of said upper and lower faces of said side block seals to prevent extrusion of said side block seals within said ram guideway of said blowout preventer.

2. A variable bore packer used in a ram-type blowout preventer for oil and gas drilling operations according to claim 1, wherein:

said side block seals substantially conform to said ram guideway of said blowout preventer.

3. A variable bore packer used in a ram-type blowout preventer for oil and gas drilling operations according to claim 2, wherein:

said wing retainer plates include a planar portion and a depending outer portion, said depending outer portion positioned below the surface of said side block seals and adjacent said ram guideway of said blowout preventer.

4. A variable bore packer used in a ram-type blowout preventer for oil and gas drilling operations according to claim 3, including:

an elongated slot in said planar portion of said wing retainer plates.

5. A variable bore packer used in a ram-type blowout preventer for oil and gas drilling operations according to claim 3, further including:

a packer pin molded within each of said side block seals, said packer pin including horizontal and vertical portions, said vertical portion including reduced diameter end segments that engage said elongated slots in said planar portion of said wing retainer plates.

6. A variable bore packer used in a ram-type blowout preventer for oil and gas drilling operations according to claim 5, wherein:

said horizontal portion of said packer pin includes a slot for securing said packer member of said variable bore packer to a ram.

7. A variable bore packer used in a ram-type blowout preventer for oil and gas drilling operations according to claim 6, wherein:

said plurality of packer inserts molded within said elastomeric material surround said central opening of said packer member.

8. A variable bore packer used in a ram-type blowout preventer for oil and gas drilling operations according to claim 7, wherein:

said packer inserts include a top plate, a bottom plate and a central web positioned therebetween; and,

said top plate, said bottom plate and said central web are integrally formed.

9. A variable bore packer used in a ram-type blowout preventer for oil and gas drilling operations according to claim 8, wherein:

each of said top and bottom plates includes a guide lip and a guide shoulder; and,

said plurality of packer inserts coact to provide an irising motion to move and seat against different diameter tubular members.

10. A ram-type blowout preventer used in oil and gas drilling operations having a variable bore ram assembly, comprising:

a body with a vertical bore;

a pair of opposing bonnet assemblies laterally disposed in said body;

a pair of opposing variable bore rams laterally moveable within said bonnet assemblies;

said variable bore rams providing a seal around a tubular member having a diameter within a predetermined range, said tubular member disposed within said vertical bore upon closing of said variable bore rams;

said pair of variable bore rams each includes a ram body, a top seal and a packer member;

a packer member moveable within a ram guideway of a blowout preventer, said packer member molded of elastomeric material having a central opening sized to fit closely about a tubular member upon closure of said blowout preventer;

a plurality of packer inserts molded within said elastomeric material into a unitary structure to form an insert array to move and seat against different diameter tubular members to prevent extrusion of said elastomeric material between said packer inserts and the tubular member;

said unitary structure is molded to form a pair of side block seals integral with said packer member, said side block seals having an upper and lower face; and,

a pair of wing retainer plates molded within each of said upper and lower faces of said side block seals to prevent extrusion of said side block seals within said ram guideway of said blowout preventer.

11. A ram-type blowout preventer used in oil and gas drilling operations having a variable bore ram assembly according to claim 10, wherein:

said side block seals substantially conform to said ram guideway of said blowout preventer.

12. A ram-type blowout preventer used in oil and gas drilling operations having a variable bore ram assembly according to claim 11, wherein:

said wing retainer plates include a planar portion and a depending outer portion, said depending outer portion positioned below the surface of said side block seals and adjacent said ram guideway of said blowout preventer.

13. A ram-type blowout preventer used in oil and gas drilling operations having a variable bore ram assembly according to claim 12, including:

an elongated slot in said planar portion of said wing retainer plates.

14. A ram-type blowout preventer used in oil and gas drilling operations having a variable bore ram assembly according to claim 13, further including:

a packer pin molded within each of said side block seals, said packer pin including horizontal and vertical portions, said vertical portion including reduced diameter end segments that engage said elongated slots in said planar portion of said wing retainer plates.

15. A ram-type blowout preventer used in oil and gas drilling operations having a variable bore ram assembly according to claim 14, wherein:

said horizontal portion of said packer pin includes a slot for securing said packer member of said variable bore packer to a ram.

16. A ram-type blowout preventer used in oil and gas drilling operations having a variable bore ram assembly according to claim 15, wherein:

said plurality of packer inserts molded within said elastomeric material surround said central opening of said packer member.

17. A ram-type blowout preventer used in oil and gas drilling operations having a variable bore ram assembly according to claim 16, including:

said packer inserts include a top plate, a bottom plate and a central web positioned therebetween; and,

said top plate, said bottom plate and said central web are integrally formed.

18. A ram-type blowout preventer used in oil and gas drilling operations having a variable bore ram assembly according to claim 17, including:

each of said top and bottom plates includes a guide lip and a guide shoulder; and,

said plurality of packer inserts coact to provide an irising motion to move and seat against different diameter tubular members.