Lifting-lowering mechanically operated test tools, catalog page 55
Open Hole Bypass Valve
Weight-operated bypass for open-hole testing with delayed opening
Description
This bypass valve is connected below the tester and has the following functions:
- When running in or pulling out, if there is hole shrinkage, kill fluid can flow through the bypass to reduce piston and swab forces
- After the test, it equalizes the pressure above and below the packer to help unset the packer
Features
- Operated only by lifting and lowering — simple structure and easy operation
- Bypass ports provide a flow channel
- Slacking off weight to set the packer closes the bypass ports quickly
- When lifting to unset the packer, the time-delayed opening of the bypass ports provides a safety margin
Operation
The bypass valve is operated by lifting and lowering the string. Lowering the string closes the bypass quickly; lifting the string opens the bypass ports after a time delay.
