GoM: BHP divests ownership interest in Neptune 24 May 2021 EnVen Energy Ventures to transfer its 35 per cent ownership interest and operatorship of the Neptune field in the deepwater Gulf of Mexico. Neptune is structured as a joint venture and is operated by BHP (35 per cent) with co-owners EnVen Energy Ventures (30 per cent), W&T Energy VI (20 per cent) and 31 Offshore (15 per cent). BHP President Petroleum Operations, Geraldine Slattery said: 'As a reputable operator with deepwater experience in the Gulf of Mexico, EnVen is ideally-placed to take operatorship of Neptune and we’re committed to a safe and smooth transition of operations.