In April 2013, the Ocean Rig Olympia started drilling a first well at 1700 metres of water depth to test the pre-salt potential of Diaba, an oil block located in Gabon’s southern basin and owned by Total Gabon (42.5%), Marathon Oil (21.25%), Cobalt International Energy (21.25%) and the government of Gabon (15%). This is the first deepwater or ultra-...