TSHWANE (miningweekly.com) – The Council for Geoscience (CGS) has embarked on a three-year research programme involving a range of geoscientific investigations associated with the drilling of a vertical deep-core borehole to better conceptualise some of the geological issues related to potential shale gas resources in South Africa.
The study area is around the Western Cape town of Beaufort West, the largest town in the arid Karoo region, which is considered to be the most prospective area for shale gas development in the country, with technically recoverable shale gas volumes that could range from 30-trillion cubic feet (tcf) to 500 tcf, according to the Petroleum Agency of South Africa.
Speaking at the CGS 2016 conference in Tshwane on Thursday, CGS shale gas project task leader Dr Luc Chevallier informed delegates that the research programme had been under way since July 2015, and that initial studies, including geological mapping, ground geophysics and hydrogeology work, were scheduled for completion by the end of March.
He added that there was limited knowledge about the shale gas gas said to be embedded in the Karoo basin.
"Shale gas exploration in South Africa is currently facing two major unknown geological concerns. The first relates to the lack of clarity with regard to the amount of economically recoverable gas trapped in the Karoo formations,” commented Chevallier.
The second unknown geological concern included the geo-environmental problems linked to the nature and the structure of the rock, groundwater migration and microseismicity in the area.
Chevallier explained that new geological information on the Karoo was needed to define an environmental baseline and to assess the amount of recoverable gas – mainly from the Whitehill and Prince Albert formations.
The research programme would assess various geo-environmental impacts, such as groundwater dynamics, including possible contamination, and would monitor potential seismic interferences.
The programme aimed to eventually drill a 4 000-m-deep stratigraphic borehole at the pilot site. In addition, the CGS would undertake surface and groundwater investigations.
Chevallier added that, once the technical work was completed, socioeconomic studies would be conducted to assess the economic benefits against the social dynamics and environmental impact of exploring for shale gas in South Africa.
"Upon completion, the study will have interrogated the whole value chain of shale gas exploration, apart from the technology associated with the field," he concluded.