The well is situated in the Cayar Offshore Profond block about 65km northwest of Dakar in nearly 1,800m of water.
Kosmos drilled the well to a total depth of 4,485m and encountered 31m of net gas pay in good quality reservoir in the Lower Cenomanian objective.
The company said results confirm that an inboard gas fairway extends about 200km from the Marsouin-1 well in Mauritania via the Greater Tortue area on the maritime boundary to the Teranga-1 well.
Kosmos has to date drilled five consecutive exploration and appraisal wells in the fairway and discovered a gross Pmean resource of about 25 Tcf.
The fairway is estimated hold over 50 Tcf of resource potential.
Kosmos Energy chairman and CEO Andrew Inglis said: "Given the scale and quality of the gas resource discovered along the inboard trend, our focus is to move this resource through to development.
"Our forward exploration plan is to mature the two independent tests with oil potential in northern Mauritania and in the outboard of Mauritania and Senegal for drilling in 2017."
Kosmos owns a 60% stake in the Teranga-1 well. Timis Corporation and Société des Pétroles du Sénégal hold 30% and 10% interests respectively.
Since 2014, Kosmos held rights to carry out exploration in the St. Louis Offshore Profond and Cayar Offshore Profond license areas under production sharing contracts with the Government of Senegal.
