Karoo shale gas deposits ‘less than expected’
THE Karoo basin probably has a 30th of the shale gas deposits that some estimates had suggested, deflating expectations of an energy bonanza, a study said.
The findings by the SA Journal of Science were published shortly before the expected award of the first shale gas exploration licences in the region.
The government had said an award could happen by the end of the month after environmental objections delayed the process.
Gas development plans have already drawn opposition from campaigners, who say they threaten the environment of the semi-arid area, famed for its rugged scenery and rare wildlife.
Geologists at the University of Johannesburg and three other institutions estimated the gas resource was probably 13 trillion cubic feet (tcf ), the bottom of a range of estimates that had put deposits between 13tcf to 390tcf, the study said.
In 2015, the US Energy and Information Administration (EIA) estimated the Karoo Basin’s “technically recoverable shale gas resource” at 390tcf, making it the eighth largest in the world and second largest in Africa, behind Algeria. At 13tcf, it ranks 34th out of 46 nations in EIA estimates.
However, the authors of the study said that “such low estimates still represent a large resource with developmental potential for the South African petroleum industry.”
“To be economically viable, the resource would be required to be confined to a small, well-delineated ‘sweet spot’ area in the vast southern area of the basin,” they wrote.
The study said previous estimates were “speculative” and had been made without measurements of gas content.
Environmentalists and farmers have staunchly opposed opening up the Karoo for development, which would require “fracking”, a technique involving pumping water and chemicals at high pressure to crack the rock and release the gas. – Reuters