Downhole Safety Valve
The Weatherford downhole safety valve is an annulus-pressure-activated, single-cycle ball valve that acts as a barrier to prevent the uncontrolled release of reservoir fluids. The valve is run in the ball-open position, and operating pressure is set by a rupture disk that is preselected based on well parameters. Upon rupturing the disk, hydrostatic pressure forces the valve to close. Once in the closed position, the valve cannot be reopened and isolates the formation.
With use of a slotted lower ball seat, the pump-through capability of the valve facilitates well-kill. When tubing pressure exceeds formation pressure, the ball valve is pumped off the upper seat, allowing kill fluids to be bullheaded through at a maximum rate of 4 barrels per minute. Once the tubing pressure drops below formation pressure, the ball reseals on the seat.
- Cased-hole testing operations
- Production testing
- Perforating operations
Features and Benefits
- The high-accuracy rupture disk (± 2 percent of nominal burst pressure rating) ensures controlled tool operation.
- Pump-through facility enables bull-heading of kill weight fluid.
- Full-bore ID of the valve, before ball closure, facilitates unrestricted flow and access for well interventions.
The Weatherford downhole safety valve is an annulus-pressure-operated ball valve with a pump-through feature that enables pumping well fluid back to the reservoir to regain control of reservoir fluids release.