Ghana will join the club of oil-producing nations this year, offering it the chance to transform the fortunes of its aid-dependent economy.

Yet other countries have seen how the blessing of oil can turn into a curse, crowding out other sectors of the economy while triggering public spending sprees, official corruption and even fuelling insecurity.

Here are some of the risk factors:

THE OIL WINDFALL

A string of discoveries in the Jubilee offshore oilfield from 2007 mean Ghana is confident of total reserves there of around 1.6 billion barrels with potentially more in adjacent sites. First oil is seen due in December 2010, with initial output put at 120,000 barrels per day (bpd) and rising to 250,000 bpd by 2013 -- squeezing Ghana into the list of the world's top 50 producers.