The price of crude oil briefly touched $100 per barrel Wednesday. By the end of the day, West Texas Intermediate for February delivery closed up $3.64 at $99.62 per barrel on the New York Mercantile Exchange.

For more than a month, analysts have been predicting the new record nearly double the cost of only a year ago.

This week violence in Africa added urgency to investors' calculations. On Tuesday, armed gangs invaded Port Harcourt, Nigeria, a key source of oil. On the same day, a U.S. diplomat was shot and killed in Sudan.

The U.S. Energy Information Administration said Thursday that domestic crude inventories fell 4 million barrels last week. It was the seventh consecutive weekly decline and much greater than the 1.7 million barrel drop that was expected. By midday Thursday, oil futures were already well above $100 per barrel.