1. We drill in Purni formation where Sub-bituminous coal is well...

1. We drill in Purni formation where Sub-bituminous coal is well developed (Pedrica Basin)

http://dbforms.ga.gov.au/pls/www/geodx.strat_units.sch_full?wher=stratno=15684


2. Sub-bitomius coal:


http://en.wikipedia.org/wiki/Sub-bituminous_coal

http://money.ninemsn.com.au/article.aspx?id=983406


3. Ash content must be below 60%.
We have to wait for that info!!!!!!!!!!


But if you do your research Sub-bitomius coal is high in Ash conten, hoever from what i can find it is normally below 60%! (PLEASE CONTRIBUTE ON THIS POINT)

http://en.wikipedia.org/wiki/Underground_coal_gasification



Other intersting paper:
http://criepi.denken.or.jp/en/e_publication/pdf/den355.pdf