Gazpromneft discovered the Neptune field in the Sea of Okhotsk in October 2017. The discovery well was drilled on the Ayashki licence, which is part of Sakhalin-3. The operator is currently reviewing the acquired data, ahead of further appraisal works planned for 2019. A detailed assessment of the field is planned to be released in late 2018. In-place resources have been reported at 1.86 billion barrels of oil equivalent. Current reserve estimate stands at 511 million barrels of oil.