ENSCO 8504 Ultra-Deepwater Semisubmersible Contracted in Brunei

Ensco plc (NYSE: ESV) announced today that a subsidiary of the Company has entered into a drilling contract for ENSCO 8504 with TOTAL E&P Deep Offshore Borneo B.V. Delivery from the shipyard in Singapore is planned for the end ofJuly 2011 and the contract commencement will follow sea trials and mobilization to Brunei.

Chairman, President and Chief Executive Officer Dan Rabun commented, "We are very pleased that TOTAL has chosen ENSCO 8504 for its drilling program. Our ENSCO 108 jackup drilling rig currently is working for TOTAL in Brunei and we appreciate the opportunity to expand our relationship with our latest 8500 Series rig. Brunei is an emerging deepwater basin and we look forward to entering this market with one of our deepwater rigs for the first time.”

The initial contract term is for drilling three exploration wells for a minimum of 180 days with a base day rate of $423,500. TOTAL may extend the term by exercising up to four options. The first two options may be exercised to complete up to three additional wells at the same day rate. The third and fourth options may be exercised to complete up to six additional wells at an escalated day rate. The fee for rig mobilization from Singapore to Brunei is $3.5 million.

When ENSCO 8504 commences operations later this year, it will become the sixth ultra-deepwater rig in the active fleet. Ensco’s other deepwater rigs are contracted in Brazil, the U.S. Gulf of Mexico and French Guiana. Two additional ENSCO 8500 Series^® rigs are under construction with deliveries scheduled in the first and second half of next year.

Ensco plc (NYSE: ESV) brings energy to the world as a global provider of offshore drilling services to the petroleum industry. With a fleet of ultra-deepwater semisubmersible and premium jackup drilling rigs, Ensco serves customers with high-quality equipment, a well-trained workforce and a strong record of safety and reliability. Ensco recently earned the top rating for overall customer satisfaction in the leading independent survey conducted by EnergyPoint Research with #1 rankings in eleven separate categories. To learn more about Ensco, please visit our website at www.enscoplc.com. Ensco plc is an English limited company (England No. 7023598) with its registered office and corporate headquarters located at 6 Chesterfield Gardens, London W1J 5BQ.

Ensco uses its website to disclose material and non-material information to investors, customers, employees and others interested in Ensco. To receive regular updates on Ensco news or SEC filings, please sign-up for Email Alerts on the website.

Statements contained in this news release that state Company or management intentions, hopes, beliefs, anticipations, expectations or predictions of future events are forward-looking statements. Such forward-looking statements include references to the expected delivery dates of ENSCO 8504, ENSCO 8505 and ENSCO 8506, mobilization, revenue, commencement and term of the ENSCO 8504 contract with TOTAL.

It is important to note that the Company's actual results could differ materially from those projected in such forward-looking statements. The factors that could cause actual results to differ materially from those in the forward-looking statements include the following: (i) changes or delays in the anticipated rig construction, sea trials, mobilization and commencement, (ii) changes in the actual drilling contract revenues or term, (iii) renegotiation, cancellation, or breach of contracts, (iv) shipyard risks, (v) force majeure events, and (vi) the operational and other risks described from time to time in the Company's SEC filings. Copies of such SEC filings may be obtained at no charge by contacting our Investor Relations Department at 214-397-3045 or by referring to the Investor Relations section of our website atwww.enscoplc.com.

The Company disclaims any obligation or undertaking to disseminate any updates or revisions to any forward-looking statements to reflect any change in Company or management expectations or any change in events, conditions or circumstances on which any such statements are based.

Source: Ensco plc