The Petroleum Agency SA (Pasa) has modelled a higher potential for shale gas in the Karoo than the previous conservative estimates of about 36 trillion cubic feet (tcf).
But a second new study by the Karoo Research Initiative (Karin) based on two drill holes, showed only limited shale gas potential.
Conflicting views provide scant reassurance for communities in the Karoo that are fighting shale gas‚ fearing fracking in an area of stark beauty and scarce water.
A lot more drilling will be needed to determine if economically viable shale gas is present‚ but drilling is less invasive than fracking‚ which involves injecting a chemical solution into deep rock to release trapped gas.
Science adviser to the Southern African Faith Communities Environment Institute Stefan Kramer said the strategic environmental Assessment into the effects of Karoo shale gas by the Department of Environmental Affairs was expected to release its findings for public comment in June-July‚ but the public would have only a limited period in which to digest these highly scientific studies and comment on them.
Final policy recommendations would take place behind closed doors.
Principal geologist at Pasa Selwyn Adams which licenses onshore and offshore gas exploration‚ said on Wednesday at the Fossil Fuel Foundation workshop on unconventional gas that‚ after new modelling‚ Pasa had estimated there was 183tcf of technically recoverable gas in place in the Whitehill formation.
This is the most prospective deposit for shale gas‚ taking into account a wider area and improvements in extraction technology.
But there was still considerable uncertainty about the porosity‚ permeability and gas content.
Pasa has concluded that the most prospective area of the Karoo for shale gas is about 78000km²‚ but the area of lowest risk within that is only about 5000km².
Falcon and Bundu have both updated the environmental management plans needed for shale-gas exploration licences but Shell‚ which has the largest concession in the Karoo‚ has not.
A director of the Centre of Excellence for Integrated Mineral and Energy Resource Analysis‚ Nic Beukes‚ said the centre’s Karin project had drilled two holes focusing on shale gas for scientific purposes‚ one near Ceres in the Tankwa Karoo and the second in Willowvale.
The Ceres drill hole found pure artesian water at about 670m‚ but minimal shale-gas potential.
The Willowvale drill hole only intercepted the Whitehill formation at about 2300m‚ and found it was intersected by dolerite sills.
Although carbon was present in both holes‚ the residual gas content was at the low limit of what might be exploitable‚ Beukes said.
If the rocks were too old‚ the carbon would become graphite‚ not fuel.
The study therefore suggested shale gas potential in the southern Karoo was limited, Beukes said.
Adams said once Falcon and Bundu were granted exploration permits‚ they would conduct seismic studies first and then exploration drilling.
Fracking would not take place before about five years. — BDLive
Pasa ups estimate for Karoo shale gas
But a second new study by the Karoo Research Initiative (Karin) based on two drill holes, showed only limited shale gas potential.
Conflicting views provide scant reassurance for communities in the Karoo that are fighting shale gas‚ fearing fracking in an area of stark beauty and scarce water.
A lot more drilling will be needed to determine if economically viable shale gas is present‚ but drilling is less invasive than fracking‚ which involves injecting a chemical solution into deep rock to release trapped gas.
Science adviser to the Southern African Faith Communities Environment Institute Stefan Kramer said the strategic environmental Assessment into the effects of Karoo shale gas by the Department of Environmental Affairs was expected to release its findings for public comment in June-July‚ but the public would have only a limited period in which to digest these highly scientific studies and comment on them.
Final policy recommendations would take place behind closed doors.
Principal geologist at Pasa Selwyn Adams which licenses onshore and offshore gas exploration‚ said on Wednesday at the Fossil Fuel Foundation workshop on unconventional gas that‚ after new modelling‚ Pasa had estimated there was 183tcf of technically recoverable gas in place in the Whitehill formation.
This is the most prospective deposit for shale gas‚ taking into account a wider area and improvements in extraction technology.
But there was still considerable uncertainty about the porosity‚ permeability and gas content.
Pasa has concluded that the most prospective area of the Karoo for shale gas is about 78000km²‚ but the area of lowest risk within that is only about 5000km².
Falcon and Bundu have both updated the environmental management plans needed for shale-gas exploration licences but Shell‚ which has the largest concession in the Karoo‚ has not.
A director of the Centre of Excellence for Integrated Mineral and Energy Resource Analysis‚ Nic Beukes‚ said the centre’s Karin project had drilled two holes focusing on shale gas for scientific purposes‚ one near Ceres in the Tankwa Karoo and the second in Willowvale.
The Ceres drill hole found pure artesian water at about 670m‚ but minimal shale-gas potential.
The Willowvale drill hole only intercepted the Whitehill formation at about 2300m‚ and found it was intersected by dolerite sills.
Although carbon was present in both holes‚ the residual gas content was at the low limit of what might be exploitable‚ Beukes said.
If the rocks were too old‚ the carbon would become graphite‚ not fuel.
The study therefore suggested shale gas potential in the southern Karoo was limited, Beukes said.
Adams said once Falcon and Bundu were granted exploration permits‚ they would conduct seismic studies first and then exploration drilling.
Fracking would not take place before about five years. — BDLive
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