Drop Ball Flapper Sub
The WellEnTech Drop Ball Flapper Sub is a tool which contains two flapper check valves. These check valves are held open until required. Ideally suited for reverse circulation operations where check valves are not required during circulation but are required when tripping out of hole so that the retrieved tubing sting incorporates a double barrier against well fluids. When activated the flappers permit flow down through the tubing but prevents flow back up through the tubing.
Description
Features
- Flappers held open
- Fully retained shear screws
- Drop ball activated
- Fluid flow down thru’ tool when flapper activated
- Double barrier to well bore fluids when activated
- No specialist assembly tools required
- Fully adjustable activation pressure
- Easily redressed
Applications
- Reverse circulation applications
- Any Well operations where a double barrier is required
Operation
The WellEnTech Drop Ball Flapper Sub is configured at surface to the required shear value. The tool is attached to the Bottom Hole Assembly and remains redundant in the tubing string until required. When the reverse circulation operation is complete. A drop ball is pumped down the tubing sting until it lands off on the ball seat in the stinger. Pressure is then applied, which shears the shear screws and drives the stinger down which activates the Flapper Check Valves. From this point on, no flow is permitted back up the tubing string enabling safe retrieval of the tool sting to surface.
