[Roccus]

Another question, when OPEC raises the price/bbl, are they raising the actual price, or are they raising the royalties (much as a 'severance tax')?

[aculeus]

Another question, when OPEC raises the price/bbl, are they raising the actual price

Yes.

[Ditto]

Another question, when OPEC raises the price/bbl, are they raising the actual price, or are they raising the royalties...

OPEC does not really set the price of oil. They set production quotas for their members. In general, assuming stable demand, More production = lower price. Less production = higher price.