Valving apparatus for downhole tools
A valving apparatus supplies increased fluid pressure to a downhole tool having fluid pressure actuated expandable packing elements. The valving apparatus includes upper and lower annular sealing surfaces and a shuttle valve which, in its normal spring surfaces and a shuttle valve which, in its normal spring biased position, engages the upper sealing surface and maintains a connection between the bore of the downhole tool and the casing annulus, thereby equalizing pressure therebetween. When pressure in the work string is increased through dropping of a ball on a seat contained in the valving apparatus, the increased fluid pressure is bypassed around the ball valve to impinge upon a piston surface incorporated on the shuttle valve, moving the shuttle valve downwardly into sealing engagement with the lower annular sealing surface and thus transmitting increased pressure to the downhole tool. Upon release of the increased pressure, The shuttle valve returns to its normal position in sealing engagement with the upper annular sealing surface and opens the fluid flow connection between the interconnected bores of the valving apparatus and the downhole tool and the casing annulus.
- Assignee:
- Baker Oil Tools Inc.
- Patent Number(s):
- US 4485876
- OSTI ID:
- 5908647
- Country of Publication:
- United States
- Language:
- English
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