http://www.atwd.com/fleet/rigs/RigDisplay.aspx?rigId='Atwood+Beacon'&classId='beaconpage'
If you look at the contract status of the Atwood Beacon it says that it is contacted to drill 4 wells with the option of 1 more (Corentyne) and this option must be exercised by 10 days after the start of the second firm well