The Ande Ande Lumut oil field was discovered in 2000 and is located in the Natuna Sea close to the Malaysia Indonesia maritime border. It has lain undeveloped due to the challenges associated with developing the field's heavy crude. The development plan approved in 2011 includes a wellhead platform linked to an FPSO vessel and long reach horizontal wells with electric submersible pump (ESP). The initial development plan only considered the development of the K Sand reservoir. In June 2016 the Ande Ande Lumut 4XST1 appraisal well proved that further reserves upside could be unlocked from the G sand reservoir. Sanction of the project initially expected in 2014 has been delayed due to the low oil price environment. In February 2016 Santos announced its intention to farm out part of its stake in North West Natuna while maintaining its operatorship.