Okay,
Professor Chaos takes the stage,

Alot of the drawbacks pointed out with other technologies are present in the production (drilling and extracting) and development (cracking and other methods) of petroleum resources.
On top of what is used "down hole" to lubricate the drill pipe and drill bit what comes back up is not always "good" for the environment or anything else for that matter. Low grade radioactives, know as normally occuring radioactive material or NORM comes up hole. Sour crude is loaded with nasty materials, of which Hydrogen Sulfide gas comes to mind. Smells like rotten eggs. You smell it and it seems to go away because it desensitizes your olfactory receivers. You can stand in a cloud of it thinking your perfectly fine, until you drop dead.
It's bad enough that the facilities storing and transporting crude and refined petroleum products have discharges all the time, but the oil platforms in and around the gulf area are always having small discharges as well.

It's the cautionary tales of the other processes that keep them from being researched and developed. It makes them sound worse than what is going on now. I can also tell you that there are lots of problems with the dangers of the platforms themselves, the offshore supply vessels that run back and forth to the different platforms and the helicopters that transport crews in and out. When it's all added together it's a wonder that petroleum is such a lucrative item. Its only because the oil comes out in thousands of barrels per day (by the way its 42 U.S. gallons to a barrel, not 55) that they make money on it.

P.S. When you control the supply you control the demand. All of the so called Oil Crises have been put ons by the petroleum industry. I have talked with tankerman who have told me that during the two previous oil crises that they sat offshore until the owner got the price he wanted for the oil in the tanker.