Although the pro-south bias leaking through this article wouldn’t have anything to do with the fact that the oil is in the south? No, of course not.
There's a school of thought that the only thing preventing Nigeria breaking up is that they are too divided to form a strong enough movement to do so.
Often people look at Nigeria and break it down into North (Hausa & Fulani), South East (Igbo), and South West (Yoruba). But that ignores the many thousands of tribal groups, communities, and factions that make up the three regions.
Earlier it was posited that Warri, a small town in the South East, could have turned around it's port into being top notch - It has large bases for Chevron and Shell. But the fighting between the different tribal groups makes it a very unattractive prospect.
If the South East tried to break away again (Biafra style), the theory is that they would be so riven by in-fighting that they would fail.