Wellhead Safety Valve
The wellhead safety valve is used during well testing and production operations conducted on platform, jackup, or land rigs. The nitrogen-precharged, fail-closed ball valve installed in the BOP stack immediately shuts in the well if an uncontrolled escape of fluids occurs at the surface between the BOP and the flowhead—a situation that is possible in both flowing and stimulation modes.
The pipe rams are closed around a ported slick joint above the valve. The valve is operated from surface by hydraulic control lines. It is opened and closed by the application and bleed off of control-line pressure. In case of emergency, the shear rams can be closed above the valve. In the event that the valve cannot be re-opened or that emergency shearing has occurred, the valve has pump-through capability for bullheading kill-weight fluids into the formation.
The amount of nitrogen precharge in the valve can be set to enable the valve to cut through 5/16-in. wireline and 1 1/2-in. coiled tubing with the assistance of hydraulic control-line pressure.
- Drillstem testing
- Production testing
- Perforating operations
Features, Advantages and Benefits
- The compact valve is compatible with all blowout preventer (BOP) stacks for added operational flexibility.
- The dual-function, ported slick joint/handling sub enhances operational efficiency.
- Pump-through capability promotes more effective well-kill operations and enhances safety and efficiency.
- The fullbore ID of the valve facilitates unrestricted flow and access for well interventions.