Have to confess you are into areas I have little knowledge about. I think $20 might be a bit low, and it's not clear whether those posters mean value to the company after costs of extraction. So, roughly 20 X 20million = 400 million = $1 per share. Common sense tells me that the value should go up with the size of the reservoir, since some of the infrastructure costs involved would be the same whether it were 20million barrels or 200million. But this is just my guesswork, I don't really know.
Regards
Dunnock