The main problem I had with that was that wherever the oil companies go they are followed by civil war, aids, degradation of the environment, and not even a helpful road infrastructure in most cases goes with the oil, since they take it off the coasts.
Prostitutes follow around the people who do get low paid jobs. The higher paid expats do not spend their earnings in the villages buying their products. They buy Nescafe etc in the shiny new capitals that come with oil businesses in Nigeria etc.
In some countries oil security firms go around killing villagers, and raping the women. It is to displace them, as is happening in Columbia with the 'war on drugs' now handily changed title to 'war on terror' which is actually war against the rebels trying to defend the natives.
I have not come to the corruption of the oil industry, bribes etc. It should be more transparent but some hope under Bush.