If one blows up, you can have $1 billion lawsuits (people killed, windows blown out, destroyed equipment).
I think the oil companies had to pay hundreds of millions of dollars in damages to refineries (and oil platforms) because of Hurricane Katrina and Hurricane Rita.
If the government ran oil platforms and refineries, the cost might be an additional 50 cents a gallon (IMHO).
We've went from something like 225 refineries to around 150...