Located about 5 km (3 mi) south of the basin-opening Tortue-1 gas discovery (renamed Ahmeyim) in approximately 2,700 m (8,858 ft) of water, Guembeul-1 was drilled to a total depth of 5,245 m (17,208 ft).
The well encountered 101 m (331 ft) of net gas pay in two excellent quality reservoirs, including 56 m (184 ft) in the Lower Cenomanian and 45 m (148 ft) in the underlying Albian. No water was encountered.
The company says the well demonstrated reservoir continuity as well as static pressure communication with the Tortue-1 well in the Lower Cenomanian, suggesting a single, large gas accumulation. Moreover, the well has significantly de-risked adjacent prospectivity, including proving the existence of excellent quality reservoirs in the Albian.
Based on the integration of the Guembeul-1 well results, the Pmean gross resource estimate for the Tortue West structure has increased to 11 tcf from 8 tcf as a result of greater reservoir (net to gross) confidence in the Cenomanian, as well as the inclusion of volumes in the Albian. The Pmean gross resource estimate for the Greater Tortue Complex has increased to 17 tcf from 14 tcf.
The company has also entered into a memorandum of understanding (MOU) with Pétroles du Sénégal (Petrosen) and Société Mauritanienne Des Hydrocarbures et de Patrimoine Minier, the national oil companies of Senegal and Mauritania, respectively. The MOU sets out the principles for an intergovernmental cooperation agreement for the development of the cross-border Greater Tortue resource.
Kosmos holds 60% interest in the Guembeul-1 well, along with Timis Corp. Ltd. at 30% and Petrosen at 10%.
Chairman and CEO Andrew G. Inglis said: “We are pleased to have delivered another major discovery with our first exploration well offshore Senegal. Guembeul-1 confirms the presence of a world-class gas resource that extends into both Senegal and Mauritania. With our successful appraisal program and support of both governments, the initial gas development is gaining momentum.
“The Guembeul-1 well continues our 100% success rate in the outboard Cretaceous petroleum system offshore Senegal and Mauritania, which we believe is a strategically important new oil and gas province and we are focused on unlocking the basin’s full potential.”
The Atwood Achiever drillship will now proceed to Mauritania to drill the Ahmeyim-2 delineation well in the southern part of block C-8. This will test the downdip limits of the field and is expected to complete appraisal of the Tortue West structure.