Classifications

• • E—FIXED CONSTRUCTIONS
  • E21—EARTH OR ROCK DRILLING; MINING
  • E21B—EARTH OR ROCK DRILLING; OBTAINING OIL, GAS, WATER, SOLUBLE OR MELTABLE MATERIALS OR A SLURRY OF MINERALS FROM WELLS
  • E21B33/00—Sealing or packing boreholes or wells
  • E21B33/02—Surface sealing or packing
  • E21B33/03—Well heads; Setting-up thereof
  • E21B33/06—Blow-out preventers, i.e. apparatus closing around a drill pipe, e.g. annular blow-out preventers
  • E21B33/061—Ram-type blow-out preventers, e.g. with pivoting rams
  • E21B33/062—Ram-type blow-out preventers, e.g. with pivoting rams with sliding rams
  • E21B33/063—Ram-type blow-out preventers, e.g. with pivoting rams with sliding rams for shearing drill pipes
• • E—FIXED CONSTRUCTIONS
  • E21—EARTH OR ROCK DRILLING; MINING
  • E21B—EARTH OR ROCK DRILLING; OBTAINING OIL, GAS, WATER, SOLUBLE OR MELTABLE MATERIALS OR A SLURRY OF MINERALS FROM WELLS
  • E21B29/00—Cutting or destroying pipes, packers, plugs or wire lines, located in boreholes or wells, e.g. cutting of damaged pipes, of windows; Deforming of pipes in boreholes or wells; Reconditioning of well casings while in the ground
  • E21B29/08—Cutting or deforming pipes to control fluid flow

Definitions

• the present invention generally relates to shear ram apparatus for use in blowout f preventers used for sealing off oil and gas wells during emergency situations in order to i
• the present invention is directed to shear ram apparatus for severing and sealing about a variety of borehole retrievables, more particularly,
• blowout preventers typically includes a housing having a throughway for the drill pipe.
• First and second ram assemblies are mounted in the housing
• Ram type blowout preventers are further subdivided into various types.
• One type is commonly referred to as the pipe ram.
• the ram assemblies when moved laterally inwardly to the closed position, simply seal about the outer diameter of the drill pipe, thereby sealing off the annulus between the drill pipe and the walls of the well
• Exemplary prior pipe ram assemblies are disclosed in U.S. Patent No. 3,434,729.
• a second ram type blowout preventer is commonly referred to as a shear ram.
• the ram assemblies when reciprocated inwardly, actual sever the drill pipe and subsequently
• the present invention is directed to shear ram apparatus for severing and sealing about borehole retrievables, particularly about flexible lines, and most particularly about multi-strand cable.
• the present invention provides an improved shear ram apparatus including means for preventing relative longitudinal movement of the blade member and anvil carried on opposable ram assemblies when those assembles are moved laterally inwardly to
• Shear ram apparatus in accord with the present invention offers the significant advantage of being able to shear a variety of flexible lines, most particularly multi-strand cable, which could not be cleanly sheared and sealed by
• Shear ram apparatus in accord with the present invention includes a housing body
• the apparatus further includes opposed first and second ram assemblies mounted in the housing on opposite sides of the throughway for
• the shear ram apparatus further includes a blade member carried on the
• first and second seal means carried, respectively, in the first and second ram assemblies for sealing the throughway
• the shear ram apparatus of the present invention includes means for preventing relative longitudinal movement of the blade member and anvil when the ram assemblies are moved laterally inwardly.
• the preferred means comprises a plurality of keys projecting laterally inwardly from the inward side of one of the ram assemblies for cooperation with guide means on the inward side of the other ram assembly.
• the key and guide means are disposed to the side of the blade member and the anvil and engage before the blade member contacts the anvil as the opposed first and second ram assemblies are moved laterally inward to shear and seal.
• the opposable shear ram assemblies and the shear ram apparatus of the present invention provide an improved apparatus for severing and sealing about flexible lines and particularly about multi-strand cables.
• the improved shear ram apparatus of the present invention prevents flexible lines, and particularly multi-strand cable, from guiding and longitudinally separating the blade member and anvil which would prevent clean shearing and sealing by the shear ram apparatus.
• This improved feature solves the long felt but unfulfilled need in the oil and gas industry for a rugged, shear ram device capable of severing all borehole retrievables, from rigid drill pipe to highly flexible lines, including multi-strand cables.
• FIG. 1 is a cross-sectional illustration of a prior art shear ram blowout preventer apparatus illustrating separation of the blade and anvil by a multi-strand cable and the
• Fig. 2 is a top plan illustration of the prior art shear ram blowout preventer apparatus of Fig. 1 illustrating in cross-section the separated and unsevered multi-strand cable;
• Fig. 3 is a cross-sectional illustration through a shear ram blowout preventer apparatus in accord with the present invention with the ram assemblies in the open position;
• Fig. 4 is a top plan illustration viewed from the line 4-4 of Fig. 3 of the shear ram blowout preventer apparatus in accord with the present invention illustrating the ram assemblies in the open position
• Fig. 5 is a cross-sectional illustration of the shear ram blowout preventer apparatus of the present invention illustrating the ram assemblies in the closed, sealing position with the key and guide means engaged to prevent relative longitudinal movement of the blade and anvil;
• Fig. 6 is a front elevational view of the laterally inward side of the first ram assembly along the line 6-6 of Fig. 3 illustrating a blade and guide means in accord with the present invention.
• Fig. 7 is a front elevational view of the laterally inward side of the second ram assembly through the line 7-7 of Fig. 5 and including the blade and guide means of the first
• the present invention provides shear ram apparatus for use in blowout preventers for severing and sealing about a borehole retrievable and, particularly, a flexible line.
• a rigid borehole retrievable is a string of drill pipe or a sinker bar.
• the shear ram apparatus of the present invention is particularly useful in severing and sealing
• Conventional shear ram apparatus is characterized by a blade member and an anvil formation carried on the laterally inward side of opposed first and second ram assemblies.
• the blade member and anvil formation are moved laterally inwardly to sever and seal.
• the blade and anvil may be guided into longitudinal movement and
• Figs. 1 and 2 illustrate prior art shear ram blowout preventer apparatus. These figures illustrate the undesirable longitudinal separation of the blade member and the anvil
• the shear ram apparatus of the present invention is distinguishable over such conventional apparatus in that the opposable first and second ram assemblies include means for preventing relative longitudinal movement and undesirable separation of the blade member and anvil formation when the ram assemblies are moved laterally inwardly.
• a ram-type blowout preventer more specifically, a shear ram apparatus comprising a housing 100.
• Housing 100 defines a central throughway 112, disposed generally vertically in use, for receipt of a borehole retrievable, typically a string of drill pipe or other flexible line, e.g., coil tubing, slicklme, wireline or multi-strand cable 114.
• a borehole retrievable typically a string of drill pipe or other flexible line, e.g., coil tubing, slicklme, wireline or multi-strand cable 114.
• terms such as “longitudinally” and “laterally” should be construed with reference to the centerline of throughway 112 unless otherwise indicated.
• the centerline of throughway 112 is generally coincident with that of the drill pipe or cable 114 in use.
• Housing 100 defines a pair of chambers 116 and 118 on laterally opposite sides of and
• Chambers 116 and 118 are substantially identical and
• the first ram assembly housed in chamber 116, comprises lower ram block 120 having laterally inward side 146.
• the laterally inward side 146 of ram block 120 is inset and chamfered at 146a.
• Ram block 120 includes cavity 122 having reduced diameter mouth 124 opening laterally outwardly. Cavity 122 receives flange member 126 connected by reduced diameter neck 128 to piston rod 130. Neck 128 extends through mouth 124 of cavity 122 with piston rod 130 being located outwardly thereof. Because of the reduced diameters of mouth 124 and neck 128, flange 126 and piston rod 130 form opposed shoulders abutting laterally outward portion 125 of ram block 120.
• piston rod 130 is connected to a piston housed in a cylinder integral with housing 10.
• piston rod 130 serves as a drive member whereby first ram block 120 may be reciprocated laterally inwardly and outwardly.
• Ram block 120 carries in an undercut formation 136 on its laterally inward side 146 an L-shaped shear blade 132.
• Shear blade 132 is characterized by projecting cutting portion 134 and is held within undercut formation 136 by horizontally disposed bolts (not shown).
• Ram block 120 includes an arcuate groove 142 on its upper surface, a transverse groove 144 along undercut formation 136 and vertical grooves (not shown) extending upwardly from the ends of transverse groove 144 to the ends of arcuate groove 142 for receiving a seal.
• the first ram assembly further comprises a first seal, conveniently in the
• This seal is a monolithic elastomeric body comprising an arcuate seal portion 138 connected at its inward ends by vertical seal portions (not shown) to laterally inward, transverse seal portion 140.
• the second ram assembly which is housed in chamber 118 comprises upper ram block
• the main drive means (piston rod 130 ') and its manner of connection to ram block 150 at its laterally outward portion 155 are substantially identical to those for ram block 120.
• Upper ram block 150 is characterized further by laterally inner side 148, inset and chamfered 148a and including cutting anvil formation 152 on its lower surface. Behind anvil formation 152, ram block 150 has been undercut to form recess 154. Ram block 150 further includes along its upper surface an arcuate groove 156 connected at its inward ends by vertical grooves (not shown) to the ends of the laterally inward portion of recess 154.
• groove system thus formed is configured to receive a second monolithic elastomeric seal body similar to that previously described and to that illustrated in Fig. 10 of U.S. Patent No. 4,540,046.
• This second seal includes arcuate portion 158 connected at the inward ends thereof by vertical portions (not shown) to the ends of transverse seal portion 160.
• Rigid support bar 162 bolted within recess 154 maintains the seal in place.
• Figs. 1 and 2 illustrate the longitudinal movement and separation of blade member 132 and anvil formation 152 in a conventional shear ram assembly caused by separation of a multi-strand cable 114 into its individual strands 114a.
• Shear ram blowout preventer apparatus in accord with the present invention overcomes this problem so that flexible lines,
• Housing 10 defines a central throughway 12, disposed generally vertically in use, for receipt of a borehole retrievable, preferably a multi-strand cable (not illustrated). Housing 10 further defines a pair of chambers 16 and 18 on laterally opposite sides of and
• Chambers 16 and 18 are substantially identical and house, respectively, first and second ram assemblies.
• the first ram assembly housed in chamber 16, comprises ram block 20 having laterally outward portion 22 for connection to the drive means and laterally inward portion 24 for carrying the shear blade 40.
• Lower ram block 20 includes cavity 26 having reduced diameter mouths 28 opening laterally outwardly. Cavity 26 receives flange members 30 connected by reduced diameter necks 32 to a piston rod 34. Necks 32 extend through
• piston rod 34 is connected to a piston housed in a cylinder integral with housing 10.
• piston rod 34 serves as a drive member whereby first ram block 20 may be reciprocated laterally inwardly and outwardly.
• inset 36 On the laterally inward surface of portion 24 of ram block 20 is inset 36 for receiving the borehole retrievable, e.g., pipe, cable or the like, to be sheared.
• the borehole retrievable e.g., pipe, cable or the like
• shear blade 40 Mounted on the lower portion of the laterally inward surface of ram block 20 is shear blade 40. Blade member 40
• cutting portion 42 is generally L-shaped in cross-section, having a laterally inwardly extending cutting portion 42 and a mounting shank 43 extending downwardly from the laterally outer extremity of the cutting portion 42.
• cutting portion 42 as viewed in plan, has a shallow notch 46 formed by oppositely inclined edges 44 to increase its contact area with the retrievable to be cut.
• Mounting shank 43 of blade member 40 includes a plurality of counter-
• sunk bores 56 for cooperation with a plurality of bores 58 in the laterally inward surface of ram block 20 for mounting of blade member 40 thereon with a plurality of mounting bolts
• Ram block 20 includes a seal means carried in an appropriate groove system. The disposition of the various parts of the groove system and the seal means relative to the remainder of the first ram assembly is readily understood with reference to Figs. 3, 4 and 6.
• Ram block 20 includes arcuate groove 48 on its upper surface, transverse groove 50
• the first ram assembly further comprises a first seal, preferably in the form illustrated in Fig. 9 of U.S. Patent No. 4,540,046.
• the seal is a monolithic elastomeric body comprising
• an arcuate seal portion 52 connected at its inward ends by vertical seal portions 53 to laterally inward, transverse seal portion 54.
• the second ram assembly which is housed in chamber 10 comprises upper ram block
• the main drive means (piston rod 34 ') and its manner of connection to ram block 70 at its laterally outward portion 72 are substantially identical to those for ram block 20. Therefore, these parts and their cooperation will not be described in detail, but have merely been given like reference numerals plus the symbol " '" (prime).
• Upper ram block 70 is characterized by laterally outward portion 72 and laterally
• Inward portion 74 terminating in laterally inward surface 76.
• Inward surface 76 is inset at 78 to aid in positioning a borehole retrievable, e.g., a multi-strand cable, for cutting relative to notch 46 of blade member 40.
• Inward surface 76 is inset and chamfered 82 along its top side and provides anvil formation 80 along its lower leading edge for cooperation with cutting portion 42 of blade member 40.
• Ram block 70 is undercut 94 for receiving blade member 42 and the severed cable or other borehole retrievable in the closed position.
• Ram block 70 includes arcuate groove 84 on its upper surface, transverse groove 86 along undercut formation 94 and vertical grooves 85 extending upwardly from the ends of transverse groove 86 to the ends of arcuate groove 84 for receiving a second seal means.
• the second ram assembly further comprises a second seal, preferably similar to that
• This seal is a monolithic elastomeric body comprising an arcuate seal portion 88 connected at its inward ends by vertical seal portions 89 to laterally inward, transverse seal portion 90.
• Rigid support bar 92 is disposed within recess 86 behind transverse seal portion 90 to maintain the seal in place.
• leading edges 66 of keys 64 preferably extend beyond the
• keys 64 engage retaining slots 60 before anvil formation 80 contacts cutting portion 42 of blade member 40.
• keys 64 are engaged with retaining slots 60 to prevent relative longitudinal movement of anvil formation 80 relative to blade member 40
• each assembly might include a key and retaining slot for cooperation with, respectively, a retaining slot and key on the other assembly.
• keys 64 might extend inwardly further than those illustrated to engage deeper retaining slots 60 in both the open and closed positions of the ram assemblies ensuring no possible relative longitudinal movement of the blade member and anvil formation. Therefore, the invention is not restricted to the preferred embodiment illustrated but covers all modifications which may fall within the scope of the following claims.

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• Life Sciences & Earth Sciences (AREA)
• Engineering & Computer Science (AREA)
• Geology (AREA)
• Mining & Mineral Resources (AREA)
• Physics & Mathematics (AREA)
• Environmental & Geological Engineering (AREA)
• Fluid Mechanics (AREA)
• General Life Sciences & Earth Sciences (AREA)
• Geochemistry & Mineralogy (AREA)
• Shearing Machines (AREA)

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Applications Claiming Priority (2)

Publications (1)

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Cited By (5)

Citations (6)

• 1992
  • 1992-01-17 DE DE19924290105 patent/DE4290105T1/de not_active Withdrawn
  • 1992-01-17 WO PCT/US1992/000449 patent/WO1992013170A1/en active Application Filing
  • 1992-01-17 CA CA 2079001 patent/CA2079001A1/en not_active Abandoned
  • 1992-01-17 GB GB9220054A patent/GB2257733A/en not_active Withdrawn
  • 1992-09-24 NO NO92923717A patent/NO923717L/no unknown

Patent Citations (6)

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