The amount of shale gas that is commercially viable in the Karoo is way below the current estimate and nowhere near the oft-quoted fifth biggest reserve in the world.
This has emerged from the early part of the government-appointed strategic environmental assessment (SEA) study looking into issues around shale gas fracking in the Karoo.
Bob Scholes, who heads the team, said yesterday there were seven studies on gas reserves in the Karoo that had been reviewed.
While the amount of gas was still an area of great uncertainty, current estimates were that there were 70-150 trillion cubic foot in the Karoo, Scholes said.
“Then you have to look at what is technically extractable, so the amount comes down. Then you have to look at what is economically extractable and it is usually an order of magnitude lower. The actual resource is probably closer to the 5-20 trillion cubic foot range.”
However, this was still significant as it was five to 20 times bigger than Mossgas, Scholes said. “But reserves are nowhere near the ‘we’ve got the fifth biggest reserve in the world’ take.”
One of the reasons reserves are probably at the lower level estimates are because during the break-up of Gondwanaland there was a large amount of hot lava intrusion which may have “cooked off the gas”. This is probably why no oil was found during Soekor’s drilling in the 1960s to 1980.
Many civic groups have expressed concern that the SEA – designed to inform government about the pros and cons of fracking in the Karoo – would not be completed before government allowed oil companies to carry out exploration drilling in the Karoo. They have said government should put exploration on hold until the two-year study had been completed.
However, Scholes said it was “highly unlikely” that any drilling would take place for the next two years, and probably no exploration fracking for the next two to five years.
Although legally exploration could go ahead, as government had published the exploration regulations in June, no company had yet been given a licence to drill. The regulations required that companies must first do a year of monitoring a range of matters, and after that they could do drilling, if given the licence. “Initially this won’t involve fracking at all. It is just making very deep holes in the ground.”
The drill samples were examined and companies would determine whether the gas content was worth pursuing. Only then would the exploration work involve fracking.