Annulus pressure operated test tools, catalog page 16
Locked-Open Test Valve for Shallow Wells
Simple lock-open test valve for wells with hydrostatic pressure below 5,500 psi
Description
This test valve was specially designed to customer requirements for shallow wells with hydrostatic pressure below 5,500 psi. It is operated by annulus pressure, can open and close the well repeatedly, and locks the well open after the pressure is released.
Features
- Consists of a ball valve mechanism, operating and rotation mechanism and nitrogen power mechanism; without an oil chamber metering mechanism, the structure is simpler and easier to maintain than other test valves
- Operating mode: apply pressure to open the well, release to lock it open, then apply and release again to close. In the locked-open position no annulus pressure needs to be held, so the tubing and casing are not under pressure for long periods
- Without a metering mechanism there is no need to wait for nitrogen pressure to balance when applying and releasing pressure, so operation is simple
- There is no pressure-compensation piston in the nitrogen chamber; the shut-in force comes from the nitrogen charged at surface
