Indonesia is offering three new unconventional oil and gas blocks on the islands of Sumatra and Kalimantan to potential bidders, an energy ministry official said on Oct. 31.

The assets on offer are one shale gas block in East Kalimantan, with potential resources of 7 trillion cubic feet of gas and 21 million barrels of oil, as well as two coalbed methane blocks in South Sumatra.

Bidders can propose a production split or make an upfront payment for the right to develop the block, Tunggal, an upstream director at the directorate-general of oil and gas who goes by one name, told reporters.

Previously, any split in production was predetermined by the Indonesian government.