The Seaway pipeline, the joint venture between Enterprise Products Partners (EPD -0.10%) and Enbridge (ENB -0.73%), has taken on a life of its own, as speculators are trying to gain access to the last bit of capacity to sell the space on a secondary market. In this video, Fool.com contributor Aimee Duffy explains what is going on and why this pipeline matters so much to oil producers and investors alike.