KIKO Locked-Open Test Valve
Test valve that opens and closes repeatedly and locks open without holding annulus pressure
Description
The KIKO locked-open test valve is a full-opening, annulus pressure-operated close/open valve used in cased holes. It can close and open the well repeatedly, and the ball valve can be locked in the open position at any step during the testing period. Operating sequence: apply operating pressure to open the well, release the pressure to lock the well open, then apply and release pressure again to close the well.
The valve consists of four parts: the ball valve operating section, ratchet section, nitrogen power section and oil chamber metering section.
Features
- Transposition section (ratchet case, ratchet mandrel, ratchet sleeve and ratchet guide ball) keeps the well locked open for long periods after pressure is released — suitable for long operations such as tubing gas-lift drainage and hydraulic pump discharge
- No annulus pressure needs to be held while the well is open, which avoids long-term stress on the casing and reduces the workload for field crews
- Oil chamber metering section ensures reliable opening and closing and provides a pressure relief differential (nitrogen pressure higher than annulus pressure), so annulus pressure fluctuations cannot affect the locked-open condition
- Collet fingers keep the tool locked open for long periods
- Four shear pins provide a 1,000 psi shear value, preventing premature opening while running in
Operation
Before running in, charge nitrogen according to surface temperature, downhole temperature and hydrostatic column pressure (see the nitrogen charge table). To open the well, apply annulus pressure (operating pressure from the nitrogen charge table), hold it for a while and then release it: the well is locked open. To close the well, apply operating pressure, hold it for a while and release it. Repeat these steps to open and close the well as many times as required.
