Annular blowout preventer

Abstract

 An annular blowout preventer having a body with a central bore therethrough, an upper plate ring, means for securing the upper plate ring to said body to form an annular packer recess therebelow surrounding and opening onto the central bore, an annular packer in said annular packer recess and means for moving said annular packer between open and closed positions, the securing means including interengaging means for engaging said body and means for moving said interengaging means between locked and unlocked positions manually or responsive to fluid pressure.

Description

Background

[0001] Annular blowout preventers have long been used to assist in controlling pressure within well bores and have generally includes a body with an inner rim, and an outer rim, an upper plate ring secured within the outer rim with a central bore extending through the body and plate ring with an annular packer recess facing onto the central bore with the plate ring forming the upper surface of the packer recess, a packer in the recess and a means to actuate the packer to closed position either on itself or on a tubular member extending through the central bore. Various means of securing the plate ring within the outer body rim have-been used, such as a threaded connection as shown in U.S. Patent No. 4,310,139; dogs which are actuated by a piston-operated cam into locking engagement with the body rim as shown in U.S. Patent No. 3,741,295.

[0002] None of the known prior art suggests a combination of both pressure responsive and manual movement from and to locked position of the plate ring in the body.

Summary

[0003] The present invention relates to an improved annular blowout preventer having a body with inner and outer upstanding rims, an upper plate ring having means for securing it to the upper portion of the outer rim which securing means is operable manually or responsive to fluid pressure, a central bore through the body and upper plate ring, a packer recess surrounding and opening onto said central bore, a resilient packer in said packer recess, and pressure responsive means for moving the packer to closed position.

[0004] An object of the present invention is to provide an improved annular blowout preventer with a top plate ring which is easily and quickly secured remotely and also manually.

Brief Description of the Drawings

[0005] These and other objects and advantages are hereinafter set forth and explained with reference to the drawings wherein:

FIGURE 1 is an elevation view of the improved annular blowout preventer of the present invention with the right half thereof in section to show the open position of its packer.

FIGURE 2 is a view similar to FIGURE 1 but showing the closed position of its packer.

FIGURE 3 is a partial sectional view showing the unlocked position of the top plate ring securing means.

FIGURE 4 is a partial sectional view showing the locked position of the top plate ring securing means.

Description of the Preferred Embodiment

[0006] Annular blowout preventer 10 includes body 12 which has lower flange 14 with upstanding inner rim 16 and upstanding outer rim 18 which is space outward from rim 16 and extends above the upper end of rim 16. Securing means 20 secures upper plate ring 22 within the upper end of outer rim 18 as hereinafter described. Central bore 24 extends through body 12 and plate ring 22.

[0007] Inner ring 26 is secured to inner rim 16 as shown and outer ring 28 is held in position between shoulder 30 on outer rim 18 and snap ring 32 positioned in groove 34 on the interior of outer rim 18. Inner ring 26 and outer ring 28 are spaced apart to receive tube 38 which connects piston 40 in chamber 42 below rings 26 and 28 to actuating plate 44 above rings 26 and 28.

[0008] Packer 46 is positioned in packer recess 48 between surface 50 of upper plate ring 22 and the upper surface 52 of inner ring 26. Packer 46 includes resilient annulus 54 with suitable support inserts 56 embedded therein and is surrounded by outer resilient annulus 58 which is engaged by actuating plate 44 as shown.

[0009] Thus as piston 40 is moved upward responsive to pressure in the lower end of chamber 42, outer resilient annulus 54 is wedged to cause packer 46 to move to its closed position shown in FIGURE 2. Pressure relieved from the lower part of chamber 42 and applied to the upper part thereof causes piston 40 to move downward to allow packer 46 and outer resilient annulus 58 to return to the position shown in FIGURE 1.

[0010] The interior of the upper end of outer rim 18 has grooves 60 therein which grooves coact with projections 62 on split ring 64 to secure upper plate ring 22 to body 12. Split ring 64 is normally in its unlocked or retracted position as shown in FIGURE 3 and has inner cam surfaces 66 which are engaged by surfaces 68 on the exterior of sleeve piston 70 so that when piston 70 is moved downward split ring 64 is cammed or wedged outward into its locking position shown in FIGURE 4. When piston 70 is moved upward split ring 64 retracts to its unlocked position. The locked position of split ring 64 with its lower end engaging upwardly facing shoulder 72 locks or secures upper plate ring 22 to outer rim 18 and thus provides securing means 20 previously mentioned.

[0011] Sleeve Piston 70 is movably positioned within split ring 64 and in surrounding relation to surface 78 on upper plate ring 22 and seal ring 80 which is secured to upper plate ring 22 by suitable fastening means such as cap screws 82. Chamber 84 between the interior of sleeve piston 70 and surface 86 on upper plate ring 22 is supplied with suitable pressure fluid, such as air. above and below piston seal 88 by ports 90 and 92. Suitable recessed fittings 90 are provided at the outer openings of ports 90 and 92. Thus air or hydraulic fluid supplied to port 90 causes piston 70 to move downward to lock securing means 20 and air supplied to port 92 causes sleeve piston 70 to move upward to unlock securing means 20. Screws 96 thread through rim 18 and are adapted to engage in groove 98 in the exterior of sleeve piston 70 to prevent inadvertent release of securing means 20 from its locked position.

[0012] Tapped holes 100 in the upper surface of sleeve piston 70 are provided to allow suitable devices such as lifting eyes 102 to provide for-the manual or mechanical lifting of sleeve piston 70 for the manual release of securing means 20. Also exerting a mechanical force on the upper surface of piston 70 moves it downward to lock securing means 20. Thus, securing means may be operated remotely by use of a pressure fluid or manually by exerting a mechanical force directly applied to piston 70 to move it in the desired direction.

[0013] Tapped holes 104 in the upper surface of upper plate ring 22 are provided to receive lifting eyes (not shown) for ease in removing and replacing upper plate ring 22.

Claims

1. An annular blowout preventer having a body having a central bore therethrough an upper plate ring, and characterized by means securing said upper plate ring to said body with an annular packer recess surrounding and facing said central bore below said upper plate ring, a resilient annular packer in said packer recess, and means for moving said resilient annular packer between open and closed positions, said securing means being movable between locked and unlocked positions manually and responsive to pressure fluid.

2. An annular packer according to claim 1 wherein said securing means includes means for engaging said body to secure said upper plate ring in its locked position.

3. An annular blowout preventer according to claim 1 wherein said securing means includes a split ring which is interengageable with said body, and a pressure responsive sleeve piston coacting with said split ring to move it to locked position and to allow it to move to unlocked position.

4. An annular blowout preventer according to claim 3 including means for retaining said piston in its position holding said split ring in locked position.

5. An annular blowout preventer according to claim 3 including means on said sleeve piston for manual movement thereof.

6. An annular blowout preventer according to claim 3 wherein said body includes an upstanding rim having grooves around its upper interior surface, and said split ring includes external projections for engaging in said grooves.

7. An annular blowout preventer according to claim 6 wherein said split ring includes a camming surface on its interior, and said sleeve piston includes a surface coacting with said camming surface on said split ring to force said split ring outward so that its projections engage in said grooves to secure said upper plate ring to said body rim.

8. An annular blowout preventer according to claim 7 wherein said split ring engaging an upwardly facing shoulder on said upper plate ring when engaged with said body rim grooves to secure said upper plate ring to said body.

9. An annular blowout preventer according to claim 1 wherein said body has an inner upstanding rim with said central bore therethrough and an outer upstanding rim having internal grooves in the upper portion of its inner surface, said upper plate ring is positioned within said outer rim and coacting with said body to define said packer recess facing inward, and said securing means includes said upper plate ring having an outer upwardly facing shoulder, a split ring positioned on said shoulder and within said outer rim and having projections on its outer periphery and a cam on its inner surface a pressure responsive locking ring positioned between the exterior of said upper plate ring and the interior of said split and having an external cam surface which coacts with the inner cam surface on said split ring, and means for supplying pressure to said pressure responsive locking ring to move it from unlocked position to locked position in which position it cams and retains split ring outward into interengagement of its projections into said internal grooves in said outer rim and from locked position to unlocked position, said locking ring having means for being mechanically engaged for manual movement between locked and unlocked positions.

Drawing