In 1998, Marathon discovered the East Orovinyare field. The discovery well encountered a 100-metre oil column in the Upper Cretaceous sandstones of the Batanga Formation. Marathon relinquished the licence in 2000, following an unsuccessful farm-out attempt. Bowleven gained ownership of the East Orovinyare field in 2007 when it acquired FirstAfrica Oil. In March 2012, Bowleven sold East Orovinyare for US$35 million to Perenco.