Diamond Offshore Drilling has bought the PetroRig II semi-submersible offshore drilling unit for $490m.

Diamond will rename the 7,500ft facility, which is being built at Jurong Shipyard, Ocean Valor.

The payment does not include initial mobilisation costs, final commissioning, drillstring or necessary spares.

In June, Diamond Offshore bought the new-build dynamically positioned semi-submersible offshore drilling unit PetroRig I and renamed the facility Ocean Courage.