Essential reading for every Nigerian. A report by Chatham House on "Thirst for African Oil Asian National Oil Companies in Nigeria and Angola"

Oil-for-infrastructure deals have been successful elsewhere in Africa, notably in Angola and Sudan. This suggests that the concept per se is not at fault. But in Nigeria the scheme went wrong because it was not properly conceived and there were no inbuilt guarantees
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Looking at the oil-for-infrastructure deals as a whole, the projects were vague and lacking in technical or financial detail. Subsequent negotiations were slow. Repeated visits by Nigerian officials to Asian capitals produced little clarity or progress and no timetables for delivery were ever announced. The projects chosen by Nigeria for Asian investment were high-cost and high-value, and offered the opportunity for
high commission payments, but they were not properly considered in the context of wider national economic planning. The political context also exposed the weakness of the arrangements. In retrospect, this was an ill-thought-out, half-baked ad hoc exercise dressed up in fine words

http://www.chathamhouse.org.uk/publications/papers/download/-/id/768/file/14524_r0809_africanoil.pdf