A lot of people are concerned with Peak Oil together with the rising internal demands of oil exporting countries. While some of the Peak Oil enthusiasts are, perhaps, way out in left field, there are definitely some potential supply concerns in our future.
Nigeria, generally considered Africa's biggest oil producer, just announced they are importing oil. See http://www.bloomberg.com/apps/news?pid=20601207&sid=aUL6cdVxk_GU.
Is the beginning of the end? Probably not, as the Nigeria problem is more about refining capacity that crude. On the other hand, Nigerian production is constrained by pipeline damage, rebels, and domestic terrorists.
One of my pet theories is that when Russia feels poor, they will need to increase the price of oil. I think Putin can with impunity disrupt Nigeria, since Nigeria is not a particularly close friend of the USA. Nigeria has a lot of AK-47s (Google AK-47 and Nigeria, 350,000 hits), http://www.mynaijanews.com/content/view/2207/228/ claims that 50,000 guns were imported "just in case" for the election. http://www.mynaijanews.com/content/view/2207/228/ claims thousands of these guns were sold to militants a few months later. Could Comrade Vladimir be providing a little export assistance?