Even if someone succeeds with cold fusion, oil will still be in great demand for at least 30 years because it is an excellent transportation fuel that holds a great deal of energy per liter of volume. Our transportation infrastructure is also designed around oil and it will take decades to convert this infrastructure over to an electricity-based infrastructure starting at the time that electricity could become extremely cheap. Nigeria doesn't have anything to worry about as far as selling it's oil at a good price during the next 30 years.
Plastic.