A third ultra-deepwater drillship has been ordered by Atwood Oceanics at an estimated cost of US $635 million, with the unit to be identical to its sister ships the Atwood Advantage and Atwood Achiever.

The Atwood Admiral will be built by Daewoo Shipbuilding and Marine Engineering Co. in South Korea under a turnkey construction contract. The drillship is expected to be delivered by March 31, 2015, with the total cost that includes two blowout preventers (BOPs), project management, drilling and handling tools, and spares.

Atwood recently increased the accordion under its senior secured credit facility by $200 million to a total of $550 million which, together with available cash and cash flows from operations, is expected to fully fund the construction of the Atwood Admiral. Upon delivery, the drillship will become the 16th mobile offshore drilling unit owned by the drilling contractor.

Its design will be identical to the previously ordered Atwood Advantage and Atwood Achiever – all three are DP-3 dynamically-positioned, dual derrick ultra-deepwater drillships rated to operate in water depths of up to 3,658 m (12,000 ft) and drill to a well depth of up to 12,192 m (40,000 ft).

The Atwood Admiral also will offer two 7-ram BOPs, three 100-ton knuckle boom cranes, a 165-ton active heave “tree-running” knuckle boom crane, and accommodation for up to 200 people.

This order comprises the execution of the option that was set to expire Sept. 30.

Atwood also has now secured an option to construct a fourth ultra-deep drillship at a similar cost to the Atwood Admiral and with an expected delivery in December 2015, which requires commitment by June 30.

At this time, the company has made no determination as to whether the option will be exercised, it said.