Well Dominator
'Well Dominator is Schlumberger's test tool for carrying out positive pressure test on liner top. After cementing the liner, the conventional sequence of operations requires multiple trips for cleaning out cement inside the liner, scrapping, and carrying out a positive and negative pressure test to ensure the integrity of the liner top. Well Dominator is run in the string in a combination of another Schlumberger tool Well Commissioner to complete all operations in a single run thus saving rig time.
It is a ball drop tool that remains hydraulically inactive while cleaning-out the casing. Dropping a ball activates pads of Well Dominator for carrying out a positive pressure test of liner top. Once the pressure test is successfully completed, dropping another ball deactivates it. A negative pressure test can be performed by Well Commissioner, which is part of the same string.