Maarten de Wit
OVER the past year rumours of a vast energy wealth stacked away beneath the Karoo have reached fever-pitch.
Gas (methane-CH4) from shale is apparently there for the picking – and a rich picking too, it is said. The extraction industry believes we all will benefit if we harvest it soon in what is presented as a proverbial win-win situation.
Nothing could be further from the truth.
First, it is not known for certain how much gas there is. Second, even if there is a significant amount it is uncertain whether it can be tapped without damaging other sub-surface resources, particularly scarce potable water reservoirs, and whether the inevitable surface damage around well heads can be fully rehabilitated.
Two camps have emerged in this Great Shale Debate.
Conservationists say gas extraction will leave massive, irreparable environmental scars on the Karoo’s iconic landscape, while others point to the health hazards. They argue that we would all be better off leaving the gas in the ground.
The counter argument stresses the strong correlation between energy use and wealth, and the theoretical fact that gas burns almost 50 percent cleaner than coal. It welcomes the potential bonanza of “cleaner” energy in the light of two professed SA priorities: to meet the 2015 UN-Millennium Goal target of poverty reduction and the stringent 2020 carbon-emission reduction targets. With access to local shale gas, South Africa could easily meet these goals, this argument goes.
But this heated debate is also part of a wider ethical debate about the looming global environmental challenge of climate change, building up to what has ironically been called “a perfect moral storm”. Should we not at least find out what we have in our own back yard that might help us meet the challenges posed by this perfect storm?
And this leads to another, narrower, question: how can we weigh up these issues to the satisfaction of all concerned and arrive at robust conclusions that will support sound policy outcomes?
Projections make it abundantly clear that there must be a change in energy production from the heavy CO2 polluters, coal and oil, to renewables like solar, wind and wave; perhaps hydrogen and nuclear. Shale gas, because of its cleaner burning, offers “bridging fuel” and a window of opportunity to wean society off coal.
In the past 10 years, shale gas has become the new fossil fuel resource in the US. In 2010, shale-gas output there was nearly five trillion cubic feet (TCF) – more than 10 times the production in 2000. It’s been projected that shale gas will account for about 46 percent of US natural gas production by 2035, and that the Marcellus Shale stretching from Tennessee to New York – an area about one-third the size of the Karoo – may hold enough gas to heat US homes and power electric plants for two decades. Shale gas exploitation has also rapidly gone international.
Today, it’s believed that shale gas may constitute more fossil energy than all global oil and coal combined, and even China is likely to become a major shale gas producer. Estimates of total gas global reserves range widely, from 800 to 30,000TCF. It’s estimated that the Karoo may have 500TCF, but this is a big thumb-suck because we know far too little about Karoo gas shales and, geologically, Karoo Shale appears less potent than Marcellus Shale.
The local shales were “imaged” in 2004 during a geophysical study to understand the origins of the Karoo basin and the Cape mountains, and this revealed the depth variations of these shales in a section traversing the Karoo where new exploration licenses are pending. These depth estimates were tested against shale samples retrieved from deep holes drilled by Soekor (Southern Oil Exploration Corporation) in the 1960s during the search for oil and gas.
From this academic work, we know the Karoo shales are likely to be found at a depth of 2km to 4.5km – perfect for tapping “tight” gas, should it be present in sufficient quantity.
But to evaluate the potential, rock samples will have to be brought to surface. And the final stages of determining whether gas can be liberated and economically harvested from these depths requires the limited breaking-up of the shale in situ. This is done by pumping water under immense pressures down the drill holes to cause hydraulic fracturing, or “fracking”.
Because shale deep underground is hard to break, or fracture, fracking may require some four million litres of fluid (in the order of 50 residential swimming pools) to complete. Moreover, the well has to be fractured repeatedly: horizontal wells are fracked10-to-20 times in one direction. Because the fractured area in horizontal wells extends over large distances, there are risks of the induced fractures intersecting existing vertical faults or natural fractures in the surrounding rocks, thus allowing gas and fracking fluids to escape upward, perhaps into aquifers, potentially degrading the quality of local groundwater.
Even more likely is the possibility of gas and fracking fluid escaping through broken casing in the drill-holes. To avoid leakage into the surrounding rocks and into water reservoirs, drill holes are cemented. But the long-term integrity of the casing cannot be guaranteed and poor well casing is a likely source of contamination.
However, ongoing advances in fracking technology and casing material may soon be able to overcome these drawbacks, and recently it has been found that saltwater, rather than freshwater, can be used for the fracking processes. It’s known that deep brine aquifers exist at great depths beneath the Karoo.
Also, fracking fluid, generally comprising up to 95 percent water and 4 percent sand (or ceramics), contains chemical “additives” that are a major concern because, just like in the food business, some are potentially dangerous to health. While they make up a small percentage of the mixture, their total volume is enough to constitute a threat to drinking water. Again, however, the technology has moved on and the additives needed may all be biodegradable in a few years from now.
To date, fracturing has been relatively free of accidents, and in North America fewer than 1 percent of wells have caused leakage or contamination. However, there have been worrying incidents, and well operations must be monitored continuously.
Concerns in the US and Canada about shale gas exploitation are as emotional, and at times as irrational, as they are in South Africa, yet there are basic differences.
In the US, debates are constructive, with environmental issues interactively debated “online” on a daily basis across a wide range of websites of non-government groups and government-sponsored agencies. Good, reliable scientific information and critical evaluation sustains the discourse here at a structurally sound level, facilitated through their immense well-trained workforce. This enables many sharp independent watchdogs to monitor and sound alarm bells. As a result protection, monitoring and fixing are successful in North America, by-and-large.
Here in South Africa, the debate appears more confrontational – I suspect due to lack of technical expertise and innovation – and we behave mostly in a tit-for-tat mode.
Academic studies showing some of the dangers of fracking are criticised as unscientific by industry representatives, while government agencies are powerless to evaluate the arguments. Research on shale gas gets one-sided responses from environmentalists when it does not suit agendas.
If South Africa is to benefit from a possible shale gas bonanza – there is no doubt about immense potential economic and social returns – it must be able to evaluate its options realistically. And for this it needs to build a new infrastructure that can dynamically monitor exploration activities on a number of fronts, by means of independent research and evaluation teams drawn from our academic and research institutions. This requires a new phase of science and technology investment.
The Karoo is a place of unique biodiversity and stark beauty, and no one in their right mind would set out to ruin that. But it is also a place of intense poverty, with many marginalised and unemployed people. There is a great chasm between rich landowners and those who own nothing. If alleviating poverty and climate change and avoiding social unrest are our agreed aims, we should think more deeply about the proposal by radical environmentalists to ban all potential fracking.
Allowing Shell and other companies to carry out exploration they need to complete in order to assess the risk of possible shale gas exploitation will in effect pay for determining the extent of some of the nation’s hidden wealth – something our own national agencies are unable to do.
Our ecological economists could then use this data to evaluate the real state of our natural bank account, long before any exploitation of the resource will begin. More robust decisions can then be made whether or not to “mine” any reserves.
Moreover, we could insist that, in parallel with its efforts to explore for shale gas, Shell looks for shallow water reservoirs that are poorly explored in the Karoo, and leaves a legacy of trained African professionals.
Like energy giant Petrobras in Brazil, exploration companies should be required to redistribute a more significant slice of their profits into educational and regulatory institutions.
The Cabinet has made it very clear that the environment will not be compromised. The energy industry must learn to work better with government agencies, environmental organisations and local communities to develop innovative technologies and practices that can reduce the environmental risks and impacts associated with shale gas development.
It should stimulate continued study and improved communication of these risks to allow society to make well-informed decisions about South Africa’s energy future.
Also, our universities are not focused on the moral issues of energy and the environment, and the lessons for the academic community are clear: do your homework well and focus on our grand challenges.
There are equally clear lessons for the government: provide funds for centres of excellence where such work can be done in earnest, and don’t take half measures.
l Maarten de Wit is professor of Earth Stewardship Science and science director of AEON (Africa Earth Observatory Network, http://aeon.org.za/) at the Nelson Mandela Metropolitan University in Port Elizabeth. This is an edited version of article in the latest issue of the South African Journal of Science.