Winterfell was designed to test a sub-salt Upper Miocene prospect. The well encountered about 26 m (85 ft) of net oil pay in two intervals.
The Winterfell well is in about 1,600 m (5,300 ft) of water and was drilled to a total depth of approximately 7,000 m (23,000 ft).
An affiliate of Beacon Offshore Energy LLC is the operator of the Winterfell well. Additional interest owners include Red Willow Offshore LLC, Ridgewood Monarch North LLC, CSL Exploration, LP, CL&F Offshore LLC, Houston Energy, L.P., Beacon Offshore Energy Exploration LLC, and Beacon Asset Holdings LLC.
Kosmos said it will now work with the partners on an appraisal plan and development options. The discovery is located within tieback distance to several existing and planned host facilities.
The company also plans to drill the Zora infrastructure-led exploration well in the Gulf of Mexico later in the year.