LIFO is illegal in some countries but is acceptable under GAAP. The Oil industry is not special here.
Percentage depletion is the IRS standard for non-renewable resources. Again, oil is given the same percentage as copper: https://www.law.cornell.edu/uscode/text/26/613
Passive loss exception is also standard: https://www.irs.gov/taxtopics/tc425
The IRS maintains a nicely detailed guide on how tax deductions work: https://www.irs.gov/publications/p535 Almost no one would say a business deducting COGS would be a "subsidy".