Oil from the Bakken shale has increasingly become the preferred oil over West Texas Intermediate, or WTI, by refineries all over the world. And, because there is so much explosive growth in production in the Bakken and the midstream oil transport capacity can't keep up, the oil is selling at a premium. In this video, Motley Fool energy analyst Joel South talks about what this means for WTI, and why he thinks Bakken oil will soon be the U.S. standard.