Tubing pressure balanced well safety valve
A well safety valve for controlling the fluid flow through a well conduit having a tubular housing and valve closure member moving between open and closed positions by a longitudinally tubular member telescopically movable in the housing. A piston and cylinder assembly is positioned in the housing, connected to the tubular member, and actuated by hydraulic fluid from the well surface for moving the valve to an open position. The valve prevents pressure in the well conduit from affecting the opening or closing of the valve by providing first and second spaced seal means between the tubular member and the housing for preventing fluid pressure in the tubular member from communicating with the piston and cylinder assembly. The outside diameter of the tubular member on which the first and second seals engage are of the same diameter whereby the tubular member is pressure balanced. The second side of the piston and cylinder assembly is vented through the housing whereby hydrostatic pressure in the well acts to close the valve. The first and second seals each include two circular seals and a vent passageway leading from between the two circular seals to the exterior of the housing for further isolating the piston and cylinder assembly from the well pressure.
- Assignee:
- Camoco, Incorporated
- Patent Number(s):
- US 4495998
- OSTI ID:
- 5877884
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
020300* -- Petroleum-- Drilling & Production
03 NATURAL GAS
030300 -- Natural Gas-- Drilling
Production
& Processing
CONTROL EQUIPMENT
CYLINDERS
EQUIPMENT
FLOW RATE
FLOW REGULATORS
FLUIDS
HYDRAULIC FLUIDS
HYDROSTATICS
NATURAL GAS WELLS
OIL WELLS
OPERATION
PISTONS
PRESSURE DEPENDENCE
RESERVOIR PRESSURE
TELESCOPES
VALVES
WELL PRESSURE
WELLS
WORKING FLUIDS