The Petrojack IV rig was delivered from Jurong Shipyard, Singapore, in January 2009 and is currently operating for PTTEP offshore Thailand under a long-term contract.
Remaining contract period is 3.5 years, lasting until the end of second quarter of 2014, Seadrill said.
The total purchase price for the rig is approximately $180m and the contract value for the 3.5-year remaining assignment is about $165m.
The rig, to be renamed West Cressida, is a high specification drilling unit and is based on the Baker Marine Pacific Class 375 design.
The rig has the capability to operate in water depths up to 375ft and drill to depths of 30,000ft.
