There are many question marks about shale gas exploitation in the Karoo, writes Sarah Wild.
|||What is fracking?
Hydraulic fracturing, otherwise known as “fracking”, is a method to extract gas from shale rock. The gas, which is mainly composed of methane, is trapped in the rock and, in order to liberate it, a fracking fluid (which is a mixture of chemicals, water and sand) is injected at high pressures into the rock. This creates fissures in the rock, which are held open by the sand in the fluid, which allows the gas to escape.
Fracking is a controversial practice. Some say that fracking-acquired shale gas is better for the climate than burning coal. Others say that it damages ground water.
Read: Official warns of fracking pollution
However, since there is no precedent for this in South Africa, the strategic environmental assessment task team’s reports will focus on these issues in later chapters.
There are many question marks about shale gas exploitation in the Karoo: we do not know if there is gas and, if there is, whether it is economically viable to exploit it. The government’s strategic environmental assessment offers four futures, ranging from no exploration at all through to a glut of gas.
No exploration
Even without the discovery of shale, the Karoo is going to change. Climate models show that temperatures in southern Africa are going to increase disproportionately compared to the rest of the world, with semi-arid areas growing. At the moment the annual rainfall in the Karoo ranges from 100mm in the west and 400mm in the east, and water will become scarcer. The higher temperatures, as well as the increased frequency of extreme weather events, mean that land use in the Karoo will change – more game farming (as game is more resilient to drought and disease than other livestock) and a greater reliance on groundwater. This aridity and the lack of development in large tracts of the eastern Karoo will stymie economic development.
Scenario 1
It is 2050 and “shale gas” is a memory in the Karoo. When the exploration began in 2018, there was a great deal of excitement and a number of Karoo towns, especially in the central Karoo Basin, grew plump on the activity. The seismic surveys and drilling activities brought many people through the towns: international experts, trucks hauling equipment to and from the well sites, as well as setting up its infrastructure for crew and waste treatment. It created jobs for unskilled locals but these work opportunities only lasted a few years at most. The activity did trickle down to local businesses, though, and money concentrated in these towns, along with people from surrounding areas.
There were 30 wells drilled in total, split between five different spots. With climate change, water has become scarcer in the Karoo.
But by 2025, no one had discovered shale reserves that were economically viable to exploit. About 5 trillion cubic feet of gas was technically recoverable in the Karoo, substantially less than the 485 trillion cubic feet assumed. So after a period of relatively intensive exploration, companies packed up their equipment, put in place plans to rehabilitate the sites where they had drilled, and left.
Scenario 2
In the central Karoo, a gas-fuelled power station adds a bit of diversity into the Western Cape’s energy supply mix. The 1 000MW open cycle gas turbine is the only downstream application to come of the search for shale gas in the Karoo. The exploration boom of the late 2010s uncovered a relatively modest amount of gas (5 trillion cubic feet) trapped in the shale rock in the Karoo Basin.
All of the production activities take place in an area slightly larger than Stellenbosch municipality (900km²), connected via a pipeline backbone to the power station. Transmission lines had to be installed to link the power station to the Western Cape grid. The power station, with its 150 permanent positions, is a welcome employer in the region, which struggles with unemployment.
New wells are drilled regularly, as the amount of gas that comes out of a well declines quite rapidly over time. At any given point, there are about 600 wells spread out over the production area. These wells have to be linked up, not just to the power plant, but also the water treatment facility, which processes, cleans and reuses some of the water. At best, 50 percent of the water is reused. At worst, none of it is.
Because shale gas exploitation was new to South Africa, initially one in five people involved in the drilling and exploration was a skilled expat. But, over time, the country’s unconventional gas expertise has increased.
Scenario 3
The Central Karoo is a hub of shale gas production following the discovery of about 20 trillion cubic feet of economically viable gas in the area – enough to sustain production demand for several decades. In total, the production area takes up more than double the area of Pretoria (3 600km²). This area is split up into four production blocks, each the size of Stellenbosch, which are distributed around the Karoo.
In the late 2020s, South Africa built a 2 000MW open cycle gas turbine power station, mainly in response to the country’s electricity constraints. This was followed by another 2 000MW station about a decade later. New wells are constantly being drilled to compensate for the older wells that are drying up, creating temporary employment in addition to the permanent jobs at the power stations.
There is also a new gas-to-liquid plant at the coast, fed gas via a pipeline from the central Karoo. It took about five years to build, which included a great deal of haggling over whether it would be located in Gauteng, at the Coega Industrial Development Zone in the Eastern Cape or in Mossel Bay in the Western Cape. Ultimately, it ended up creating 900 permanent positions, excluding the temporary opportunities to lay the pipelines and infrastructure.
CAPE TIMES
