I must be having a dull day. How are drilling rights a subsidy?
You have to pay for an exploration permit, spend massive amounts of money looking for oil, then spend billions more in drilling and exploitation. Quite a lot of that cost is in direct payments to governments at all levels for licensing, permits, impact assessments, regulatory compliance and now more than ever, public relations.
I just have a picture of old Wishbone in '49 climbing down off his mule and staking his claim. As he starts piling wash gravel, exercising his digging rights, Nelson Muntz walks past pointing "Ha Ha, subisidised bastard!"