As planned with the customer, commencement of operations began by spudding the initial well followed by a short period of final acceptance testing (estimated 7-10 days at zero rate in October 2009) before recommencing operations. No similar planned downtime is anticipated going forward.

Chairman, President and Chief Executive Officer, Dan Rabun commented, “We have achieved another important milestone with ENSCO 8501 commencing operations. Ensco International already has invested more than half of the $3 billion committed to the ENSCO 8500 Series newbuild program, and we are well on our way toward having the world’s largest fleet of ultra-deepwater semisubmersibles capable of drilling in water depths of 7,500’ or deeper.” Rabun added, “We now have three ultra-deepwater semisubmersibles in our active fleet to complement our premium jackups around the globe.”

Senior Vice President, Carey Lowe stated, “Recent major discoveries in the ultra-deepwater golden triangle of the Gulf of Mexico, Brazil and West Africa highlight the growing need for ultra-deepwater drilling. ENSCO 8500 Series semisubmersibles are ideally suited to drill in these regions, as well as Australia, Southeast Asia and many other ultra-deepwater markets.

ENSCO 8502 and ENSCO 8503 are scheduled for delivery in the first and fourth quarters of 2010, respectively, each with two-year contracts in the Gulf of Mexico. ENSCO 8504 is scheduled for delivery in 2011. ENSCO 8505 and ENSCO 8506 are scheduled for delivery in 2012. Keppel FELS Limited is the builder of the ENSCO 8500 Series seven-rig fleet.