I havent made any reasech on the topic but i believe that a fall on oil price at this time period is to increase the demand for oil in europe. Most oil companies think they are American ones. This period Russia tries to supply the european market with gas instead of oil, and they succeed it in Greece. I believe that both usd and euro are having critical time, so for America the European market is ideal. I think we can clearly see some kind of competition there.