I just posted something to this effect, but I'm not aware of any special tax breaks just for the oil industry -- at least not any significant ones.
There is a domestic manufacturing credit, which is available to everyone that is manufacturing anything in the US. Excluding Oil/Gas from that tax credit would be penalizing them in particular.
There is also a depletion allowance that effectively writes down the value of the asset (the oil/gas well) as it is depleted. Think of it as a form of depreciation. But, that's also available to all resource extraction industries (mining for coal, precious metals, minerals, rare earths, etc). All businesses do the same thing with their capital assets, so it's not anything unusual.
This is a talking point, and nothing more. On average, the large integrated oil companies (Shell, ExxonMobil, etc.) have a net profit margin of only 8%. See for yourself:
http://biz.yahoo.com/p/1conameu.html
Compare it to all industries:
http://biz.yahoo.com/p/sum_qpmu.html
In comparison, Apple has a net profit margin of about 28%. I'm not begrudging Apple, but just pointing out the hypocrisy of people who gripe about "big oil", but can't wait to give their money to Apple.
Excellent information.