MXPA00008452A - Blade seal for a shearing blind ram in a ram type blowout preventer - Google Patents

Abstract

A blade seal for a shearing blind ram designed for use in a standard ram-type blowout preventer used in oil and gas drilling operations is disclosed. 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 blade seal includes a generally planar shaped central member that tapers from one end to the other and is constructed of rubber. A pair of metal caps are bonded to the lateral edges of the blade seal to aid in preventing extrusion. The lower face of therubber central member includes a groove adjacent to the metal cap to aid in preventing extrusion of the rubber. A pair of the blade seals is used in the upper ram of the shearing blind ram assembly. The opposing lower ram has a upwardly facing surface that seals against the pair of blade seals after the pipe is sheared.

Description

IMPROVED BLADE SEAL FOR A BLIND CUTTING ARIETTE IN AN ARIETE BALL PREVENTOR BACKGROUND OF THE INVENTION 1. FIELD OF THE INVENTION This invention relates to an improved blade seal for use in a blind cutting ram for a ram-type burst preventer used in oil and gas drilling operations. Preventers burst ram type are part of a system pressure control used in drilling oil and gas to control the points or "jerking" pressure unexpected in the wellbore as they are commonly referred to in the industry . The burst preventer has a body with a vertical hole and a pair of opposed bonnet assemblies laterally disposed. Each bonnet assembly includes a piston which is capable of moving laterally within the bonnet assembly by pressurized hydraulic fluid. The replaceable sealing elements called "packers" are mounted on the ends of the pistons, which extend into the hole of the burst preventer. When these pistons move towards, commonly referred to as "closed preventer burst" or "closing the rams," the vertical bore closed position preventer burst is sealed and contains the "bob". These "packers" are available in a variety of configurations designed to seal the hole preventer burst when the opposing pistons move toward its closed position A type of packer has tips designed to seal around pipe of a specific size in the hole of the pop-up preventer when the pop-up preventer is "closed". Other rams are designed to cut through a drill pipe that extends through a vertical hole and seal the hole. It is this type, commonly referred to as "blind cut" rams and the blade seal to be used in the same to which the present invention is directed. These blind-cut rams face a formidable task. These must be able to cut through a piece of the drill pipe into the hole of the burst preventer and then seal against each other to contain the pressure of the drill hole during the "shake". Blind-cut rams should form a pressure-tight seal during a shake until the wellbore pressure can be controlled. The pressure of the drill hole can reach several thousand pounds per square inch during a "shake". The blind cutting ram has several rubber seal elements attached to it to ensure a complete seal of the bursting preventer orifice. These seal elements, including the blade seal of the present invention, are exposed to tremendous pressures from the drill hole. The blade seal of the present invention offers a substantial improvement by offering a simple, easy-to-manufacture blade seal that minimizes wear and tear of the elastomeric seal member. 2. Description of Related Art Various types of blind cutting rams with different blade seals have been shown and used. U.S. Patent No. 4,537,250 to J. N. Troxell, Jr., shows a cutting ram that uses a portion of hardened stitches to assist in the initiation of the cutting action. A rectangular flat seal acts like a blade seal The ramming device shown in the United States patent AGT ^ ^^^ ßjgg igg ^ & B ^^^ ^^ j gi ggI ^^^^ ^^^ No. 4,540,046 gs SW Granger et al discloses a seal with the blade rubber element attached to a metallic member. U.S. Patent No. 5,360,061 to L. M. Womble shows a burst preventer with pipe cutting rams designed to control the shape 5 of the cut end of the pipe. Patent No. 5,713,581 US Carlson D. W. et al, shows a seal of nitrile rubber blade with non-cellulosic fibers, synthetic, uniformly dispersed, to assist avoid rolling seal.

BRIEF DESCRIPTION OF THE INVENTION The blade seal for a blind cutting ram of the present invention is designed for use in a normal ram-type burst preventer used in oil and gas drilling operations. The bursting preventer has a body with an axial bore, a pair of opposing bonnet assemblies and a pair of opposing rams capable of laterally moving within the bonnet assemblies via a source of pressurized fluid to control the flow of well fluids through the axial bore of the body of the bursting preventer. The blade seal includes a central member formed generally flat that tapers from one end to the other and is built of rubber. A pair of metal covers are attached to the side edges of the knife seal to help prevent extrusion. The lower face of the central rubber member includes a slot adjacent to the metal cover to help prevent extrusion of the rubber. A pair of blade seals are used in the top ram of the blind cutting ram assembly. The opposite lower ram has a surface that faces up that seals against the blade seal torque after the pipe is cut. ^^ iíYY ^^ ¿> ii ^ i SM ^^^ ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ A principal object of the present invention is to provide an improved blade seal for use in blind cutting rams having an improved life cycle and which adjusts in the existing burst preventers. These and other objects and advantages of the present invention are set forth with specification in the appended claims to this and form a part of this disclosure.

A complete and complete understanding of the invention can be had with reference to the accompanying drawings and to the description of the preferred embodiments.

BRIEF DESCRIPTION OF THE DRAWINGS These and other objects and advantages of the present invention are set forth below and made more clear by reference to the drawings, wherein: Figure 1 is a perspective view with a section cut away of a blind cutting ram assembly using the seal of blade of the present invention, installed in a typical ram-type burst preventer used in oil and gas drilling operations. Figure 2 is an exploded view of the blind cutting ram assembly. Figure 3 is a partially exploded view of the upper ram of a blind cutting ram assembly, shown partially inverted. Figure 4 is a perspective view of the knife seal of the present invention.

DESCRIPTION OF THE PREFERRED MODALITY With reference to the drawings, and particularly to Figure 1, there is shown a somatic view of a burst preventer of ram type 10 used in the A & * sé **? T? & amp; *? oil and gas drilling operations. The ram-type burst preventer 10 includes a body or housing 12 with a vertical hole 14 and water guide passages 16 laterally disposed. The bonnet assemblies 18 are mounted to the body 12 with bolts 20 and aligned with laterally disposed guide passageways 16. Each bonnet assembly 18 includes an actuator means 22, including a piston 24 and a connecting rod 26 (shown in phantom) . Although only one guide passage 16 and one actuating means 22 are shown, it is understood by those of ordinary skill in the art that there are a pair of opposed guide passageways 16 and actuator means 22. Each connecting rod 26 is connected to an assembly of blind cutting ram 28. The The blind cutting ram assembly 28 includes a pair of knife seals 30 of the present invention. The actuating means 22 allows the ram and the blind cutting ram assembly 30 to be reciprocating movement within the guide passageways 16. The blind cutting ram assembly 28 is shown in exploded view in FIG. a view exploited in Figure 2 to help understand the relationship between the parts. The blind cutting ram assembly 28 includes a lower ram 32 and an upper ram 34. The lower ram 32 includes an upper seal 36 and side seals 38 sealing against the guide passageways 16. The lower ram 32 includes a blade seal 40 placed on its leading edge and the seal surface 42. The upper ram 34 includes an upper seal and side seals 46 sealing in the guide passageways 16 in a manner similar to the lower ram 32. The blade seals 30 are placed on the underside of the upper ram 34. Referring to FIG. 3, the upper ram 34 is shown reversed from its position of Figure 2 to better illustrate the placement of the knife seals 30 in the same. A pair of tapered slots 48 are machined in the lower face 50 of the ram upper 34. Tapered grooves 48 include orientation slots 52 in their side walls for alignment and positioning with knife seals 30. As best seen in Figure 4, knife seal 30 is a generally flat rubber member 54. having a first end 56 and a second end 58. The first end 56 and the second end 58 are connected by an upper surface 60 and a lower surface 62 (the knife seal 30 is shown inverted from its normal orientation). The side sides 64 taper from the first end 56 to the second end 58. The outer covers 66 are attached to the side sides 64 with shoulders 68 formed therein and sized to adjust the slots 52 as shown in Figure 3. longitudinal grooves 70 are formed in the member 54 parallel and adjacent to the outer covers 66. The longitudinal grooves help to prevent extrusion of the rubber flat member 54 during operation. A typical operation sequence is as follows. With the blind cutting ram assembly 28 installed in the burst preventer 10, the rams are closed. This causes the pipe 32 to be cut and the lower face 50 of the upper ram 34 and the seal surface of the lower ram 32 to slide over each other in a tight fitting relationship. The continuous movement causes the seal surface 42 of the lower ram 32 to contact and seal against the lower surface 62 of the knife seals 30. The upper seals 36 and 44 and the side seals 38 and 46 also seal against the guide passages. 16 to ensure a complete seal of vertical hole 14 after cutting. The construction of my improved blade seal for a blind cutting assembly will be readily understood from the foregoing description and it will be noted that I have provided an improved blade seal that has an improved life cycle and adjusts in existing burst preventers. In addition, although the invention has been shown and described with respect to certain preferred embodiments, it is obvious that they will occur alterations and modifications equivalent to other experts in the art when reading and understanding the description. The present invention includes all these alterations and equivalent modifications, and is limited only by the scope of the appended claims.

Claims (12)

1. A ram-type burst preventer for oil and gas drilling operations including a blind-cut ram, characterized in that it comprises: a body with a vertical orifice; a pair of opposing bonnet assemblies laterally disposed within said body; a pair of opposing blind cutting rams capable of moving laterally within the bonnet assemblies; and a pair of blade seals for sealing against an opposite blind cutting ram disposed in one of said blind cutting rams.

2. A ram-type burst preventer for oil and gas drilling operations that includes a blind cutter ram, in accordance with claim 1, further characterized in that: each of said blade seals is a generally planar member having a first end and a second end; said first end and said second end of the generally flat member connected by an upper surface and a lower surface and a pair of lateral sides; said side flanges tapering from said first end of the generally planar member toward the second end of said generally planar member; and each of said pair of lateral sides having an outer cover.

3. A ram-type burst preventer for oil and gas drilling operations that includes a blind-cut ram, in accordance with the claim 2, further characterized in that said generally planar member is rubber molded; and said lower surface of the generally planar member includes a longitudinal groove parallel to said lateral sides.

4. A ram-type burst preventer for oil and gas drilling operations including a blind cutter ram, according to claim 3, further characterized in that said outer casing is formed of metal.

5. A ram-type burst preventer for oil and gas drilling operations that includes a blind-cut ram, in accordance with the 10 claim 4, further characterized in that the outer cover includes a shoulder formed therein for engagement with a complementary groove formed in said blind cutting ram.

6. A blind-cut ram assembly for a ram-type burst preventer used in oil and gas drilling operations, characterized 15 because it comprises: an upper ram and a lower ram; said upper ram and said lower ram including upper seals and sides to seal in a guide passage of a ram-type burst preventer; a plurality of blade seals positioned on the underside of said upper ram; and said lower ram including a seal surface for engagement with said plurality of blade seals when the blind cutting ram assembly is closed.

7. A blind cutting ram assembly for a ram-type burst preventer 25 used in oil and gas drilling operations, in accordance with claim 6, further characterized by: each of said blade seals is a generally planar member having a first end and a second end; said first end and said second end of the generally flat member connected by an upper surface and a lower surface and a pair of 5 lateral sides; said side flanges tapering from said first end of the generally planar member toward the second end of said generally planar member; and each of said pair of lateral sides having an outer cover.

8. A blind cutting ram assembly for a ram-type burst preventer used in oil and gas drilling operations, in accordance with claim 7, further characterized in that said generally planar member is molded of rubber; and said lower surface of the generally planar member includes a longitudinal groove parallel to said lateral sides. 15

9. A blind-cut ram assembly for a ram-type burst preventer used in oil and gas drilling operations, according to claim 8, further characterized in that said outer cover is formed of metal.

10. A blind-cutting ram assembly for a ram-type preventer 20 used in oil and gas drilling operations, in accordance with claim 9, further characterized in that the outer shell includes a shoulder formed therein for the coupling with a complementary groove formed in said blind cutting ram.

11. A blade seal for a blind cutting ram for a ram-type burst preventer 25 used in oil and gas drilling operations, characterized in that it comprises: ^^^ X ^ 7 ^^? ¿^ M¡7 ^^ If ^ a generally flat member having a first end and a second end, said first end and said second end of said generally flat member connected by a surface upper and a lower surface and a pair of lateral sides; said side flanges tapering from said first end of the generally planar member toward the second end of said generally planar member; and each of said pair of lateral sides having an outer cover.

12. A blade seal for a blind cutting ram for a ram-type burst preventer used in oil and gas drilling operations, in accordance with claim 11, further characterized in that said generally planar member is molded of rubber; and said lower surface of the generally planar member includes a longitudinal groove parallel to said lateral sides. 13 A blade seal for a blind cutting ram for a ram-type burst preventer used in oil and gas drilling operations, in accordance with claim 12, further characterized in that said outer shell is formed of metal. 14. A blade seal for a blind cutting ram for a ram-type burst preventer used in oil and gas drilling operations, in accordance with claim 13, further characterized in that the outer shell includes a shoulder formed therein. for coupling with a complementary groove formed in said blind cutting ram. SUMMARIZES A blade seal for a blind cutting ram designed for use in a normal ram-type burst preventer used in oil and gas drilling operations is described. The burst preventer has a body with an axial bore, a pair of opposing bonnet assemblies and a pair of opposing rams capable of laterally moving within the bonnet assemblies via a source of pressurized fluid to control the flow of the fluid from the bore. well through the axial hole of the body of the burst preventer. The blade seal includes a central member formed generally flat that tapers from one end to the other and is constructed of rubber. A pair of metal covers are attached to the side edges of the knife seal to help prevent extrusion. The underside of the central rubber member includes a groove adjacent to the metal cover to help prevent extrusion of the rubber. A pair of knife seals are used in the upper ram of the blind cutting ram assembly. The opposite lower ram has an upward facing surface that seals against the blade seal torque after the pipe is cut.