Kosmos Energy announced that the Tortue-1 exploration well, drilled to test the Tortue West prospect, which forms part of the Greater Tortue Complex, in Block C-8 offshore Mauritania has made a significant, play-opening gas discovery.
Based on the preliminary analysis of drilling results and intermediate logging to a depth of 4,630 m, Tortue-1 has intersected 107 m of net hydrocarbon pay. A single gas pool was encountered in the primary Lower Cenomanian objective. The Lower Cenomanian is comprised of three excellent quality multi-Darcy reservoirs totaling 88 m in thickness over a gross hydrocarbon bearing interval of 160 m. A fourth zone, 19 m thick, was penetrated within the secondary Upper Cenomanian target over a gross hydrocarbon-bearing interval of 150 m.
“Volumetrically, the Tortue-1 well has far exceeded our pre-drill expectations and has discovered a large scale gas resource. Our seismic imaging indicates the areal extent of Tortue West could cover approximately 90 sq km that will be better defined with appraisal drilling,” Andrew Inglis, Chairman and Chief Executive Officer, said. “Importantly, given the results and excellent well-to-seismic calibration, the Tortue-1 well has significantly de-risked our large and under-explored 27,000 sq km deepwater position in Mauritania. Our acreage offers substantial follow-on prospectivity including a diverse range of Cenomanian as well as deeper Cretaceous plays and fairways with strong dependency.”
An appraisal program is being planned to delineate the Tortue West discovery. In addition, the Marsouin-1 exploration well, located in the central part of Block C-8, is expected to spud in Q3 2015. An exploration program is also being formulated to test the other prospects in the Greater Tortue Complex, which extends into the St. Louis Offshore Profond Block in Senegal, including the Tortue East and Tortue North prospects. In support of this program, a 3D seismic survey acquired over our Senegal blocks in 2014 is currently being processed and interpreted.
“Our results demonstrate that our organic deepwater exploration business model, which targets early access to build large acreage positions with significant follow-on dependent prospectivity, can deliver significant value for our shareholders,” Brian Maxted, Chief Exploration Officer, said.
Located approximately 285 km southwest of Nouakchott in 2,700 m of water, and drilled with the Atwood Achiever drillship, the Tortue-1 well is now drilling to the planned total depth of approximately 5,250 m. Kosmos currently owns a 90% interest in the Tortue Prospect, along with Société Mauritanienne Des Hydrocarbures et de Patrimoine Minier (SMHPM) at 10%. Since 2012, Kosmos has held rights to conduct exploration in the C-8, C-12 and C-13 contract areas under production sharing contracts with the Government of Mauritania.
In March 2015, Chevron Mauritania Exploration, a wholly owned subsidiary of Chevron Corporation, acquired a 30% non-operated interest in the C-8, C-12 and C-13 contract areas under production sharing contracts. Chevron has an option to elect to participate at a 30% interest in the Tortue Prospect, subject to Chevron paying a disproportionate share of their costs related to the Tortue-1 exploration well. The blocks are contiguous, range in water depth between 1,000 and 3,000 m, and have combined acreage of approximately 27,000 sq km.