Over the last, what, decade or so there have been mergers and consolidations of oil companies, resulting in fewer companies and less competition.
The fact that there are fewer companies in the U.S. does not necessarily mean there is less competition. In the industry I work in, there are only two companies of appreciable size, and we compete intensely. Economies of scale are a reason why companies merge. Furthermore, the cost of refining is a small part of the overall cost we pay at gas station. 75% of the cost goes to the crude producers, most of whom are run by foreign governments.
And because oil is allowed, or treated as a speculative commodity on the open market, the prices are artificially driven up by non oil industry profit seekers.
Are you ignorant of the fact that traders also speculate that prices drop? And from everything I've read in the finacial news, people seeking only to preserve their wealth due to a declining dollar are most responsible for the very recent oil price hikes.
The current 'free market' system isn't working for anyone but the oil producers and speculators.
If one person wants to buy oil and finds someone who wants to sell, who the hell are you (or the government) to step in and say they can't do so?
The best solution to a shortage is to wait. When prices rise, harder to reach oil becomes economically viable to extract, but unfortunately it takes years to develop oil fields. All the government can do is get out of the way--do away with regulation on expansion of oil fields.