Diamond Offshore Announces Order for Deepwater
Semisubmersible Rig


HOUSTON Jan. 9, 2012

Diamond Offshore Drilling, Inc. (NYSE:DO) today announced that a subsidiary has entered into a contract with Keppel AmFELS shipyard in Brownsville, Texas for the construction of a moored semisubmersible rig with delivery scheduled for the third quarter of 2013. Total cost, including commissioning, spares and project management, but excluding capitalized interest, is expected to be approximately $300 million and to be paid out of available funds.

The rig, to be named the Ocean Onyx, will be designed to operate in water depths up to 6,000 feet and will have a variable deck load of 5,000 long tons, a five-ram blowout preventer, and quarters capacity for 140 personnel.

“We think significant opportunity remains for new deepwater units,” said Larry Dickerson, President and Chief Executive Officer of Diamond Offshore. “No new capacity targeting the standard midwater and deepwater markets is currently under construction, and this rig should be ideally suited to meet emerging demand in this segment. When added to our three ultra-deepwater drillships under construction, this unit will continue the process of renewing Diamond’s fleet.”

“We will construct the Ocean Onyx utilizing an existing hull from a Diamond Offshore cold stacked unit, which previously operated as the Ocean Voyager. This should allow the Ocean Onyx to be built and placed into service in approximately half the time and at half the cost of current newbuilds.”

About Diamond Offshore
Diamond Offshore provides contract drilling services to the energy industry and is a leader in deepwater drilling. Diamond Offshore’s fleet of offshore drilling rigs consists of 32 semisubmersibles, 13 jack-ups, and one drillship, in addition to three ultra-deepwater drillships currently under construction. For additional information and access to SEC filings, please visit the Company’s website at www.diamondoffshore.com.

Diamond Offshore Drilling, Inc. press release