Millions of barrels of Nigerian and Angolan crude remain unsold in the December and January loading programs, as they struggle to compete with ample supply and cheaper cargoes, traders and analysts have told Reuters. Nigeria alone had about 20 million unsold cargoes as of December 17, two traders told the publication. In addition, there are a lot of Angolan cargoes still waiting for buyers for the December and January loadings. As many as 26 cargoes remain unsold, signaling that there is a lot of supply from other producers and much…