DALLAS – Kosmos Energy (NYSE: KOS) says it has made a significant, play-opening gas discovery in block C-8 offshore Mauritania.
The drillship Atwood Achiever drilled the Tortue-1 well, designed to test the Tortue West prospect, 285 km (177 mi) southwest of the capital Nouakchott in 2,700 m (8,858 ft) of water. Planned TD of the well is around 5,250 m (17,224 ft).
Early analysis of drilling results and intermediate logging to a depth of 4,630 m (15,190 ft) suggests the well intersected 107 m (351 ft) of net hydrocarbon pay, encountering a single gas pool in the primary Lower Cenomanian objective.
The Lower Cenomanian comprises three high-quality multi-Darcy reservoirs with total thickness of 88 m (288 ft) over a gross hydrocarbon-bearing interval of 160 m (528 ft).
Additionally, the well penetrated a fourth zone 19 m (62 ft) thick within the secondary Upper Cenomanian target over a gross hydrocarbon-bearing interval of 150 m (492 ft).
Andrew G. Inglis, Kosmos’ chairman and CEO, said: “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 [34.7 sq mi] that will be better defined with appraisal drilling…
“Our acreage offers substantial follow-on prospectivity including a diverse range of Cenomanian as well as deeper Cretaceous plays and fairways with strong dependency.”
Kosmos plans an appraisal program to delineate the discovery, and expects to spud the Marsouin-1 exploration well in the central part of block C-8 this summer.
It is also lining up a program to test other prospects, including Tortue East and North, in the Greater Tortue Complex which extends into the St. Louis Offshore Profond block offshore Senegal.
To support this program, a 3D seismic survey acquired over the company’s Senegal blocks last year is currently being processed and interpreted.
Chevron, which farmed into 30% of the C-8, C-12, and C-13 contract areas in March, has an option to take a 30% stake in the Tortue prospect by agreeing to pay a disproportionate share of costs related to the Tortue-1 well.
These three contiguous blocks, in water depths ranging from 1,000-3,000 m (3,281-9,842 ft), extend over a total area of around 27,000 sq km (10,425 sq mi).