there's some good material on Shell's website about the karoo project and its prospects.
"If exploration confirmed there was 20 tcf in the Karoo that could be commercially produced, this would have the potential to supply more than half of all our energy needs in South Africa for 20 years at current capacity" http://www.shell.com/zaf/aboutshell/shell-businesses/e-and-p/econometrix-report.html
Just 10% of the US EIA estimated 485 tcf (trillion cubic feet) shale resource could add R200 billion to GDP annually and create 700 000 sustainable jobs
