indonesia psc details, page-3

I think you're confusing their interest in the block (presently 40%, but in dispute) with the net take in an indonesia PSC

The way an Indonesian PSC works is basically this:
From production
first 10% goes to the government
of remaining 90%, all can be offset against costs, both existing exploration and dev and opertaing.
the remaining production is split say 33% to contractor, 67% to government.
Then contractor pays 44% tax on their 33%, resulting in approx 15% net to contractor.

The cost recovery is basically getting money back that you have spent.

Therefore the SALES VALUE of a discovery is 40% of 15% of reserves.

The qustion is do the reserves cover the cost of development? then you can work out an NPV.