I should elaborate anyway . . .
The high price of oil is not by itself any kind of a statement on whether there is "free market capitalism" in energy. It probably has a lot more to do with so-called inelastic supply-demand, which--according to simple economics--makes for a volatile clearing price. (This, incidentally, means that it is "just as easy" for oil to drop to $50 as go to $230 from today's $140)
Second, the extent to which oil may be distorted by perverse incentives (those that kill capitalism, for example) has IMO really nothing at all to do with the companies in the sector being large. As mentioned above, they have to be large because it is a scale business--in the extreme.
Supply should not be so inelastic in a capitalist system. There is more oil to be explored/discovered. But the incentives for that to happen are blunted by various geopolitical risks (see Venezuela, Russia, Nigeria, The Gulf) which makes it an unfortunately poor risk reward trade for the boss of BP to invest what would otherwise be a sensible amount in finding the next few North Seas.
I would suppose/hope that the long term effect of this is good for alternative energy (and the oil giants will re-invent themselves that way anyway). In the shorter term it is a lot more problematic.