Nigeria's oil finishes in 41years-World bank

The report which was presented by the World Bank’s chief economist for Africa, Shantayanan Devarajan, on Thursday said Nigeria’s and Angola’s oil reserves will be depleted in 41 and 21 years respectively.
“Nigeria, the largest regional producer, can keep supplying at 2011 levels for another 41years, while Angola, the second largest producer in the region, has about 21 years remaining at current production levels before its known reserves are depleted.
“Given the size of these reserves, it is likely that the dependence on oil resources in these countries are likely to continue in the near to medium term. Production in newly oil-rich countries such as Ghana and Ugandacould also last for several years.”
According to the World bank’s chief economist, Mineral wealth in African countries including Nigeria don’t translate toprosperity because the money accruing fromit doesn’t pass through the citizens, and the citizens don’t see the wealth as theirs.

So after oil finish, what next?