Do agree that it's a complicated mess Hank and we need intelligent unbiased people to explain it. I trust Senator Wielochowski's judgement and knowledge of oil revenue legislation. This is part of his May,2016 press release:

"Under Alaska’s current tax credit and deduction system, oil companies can claim up to 75% of their costs for new exploration, and up to 65% of their costs for new development. If you gave someone 65% of the costs to run their business, you’d probably expect a pretty good return on that investment, right? Well, we used to have a windfall profits tax that did just that – provided a fair return to Alaskans as oil prices rose, but only after the oil companies made massive profits. That’s the provision that allowed us to save $15 billion between 2007 and 2012 – the savings we are currently surviving on today."