Extraído de: un-earthed
Fracking Fears Run Deep in the Karoo
During the 1960s, with the hopes of finding oil, the state-owned company, Soekor, embarked on a series of exploration wells in the Karoo region of South Africa. In 1967, one was drilled on Skietfontein, a farm in the Aberdeen district. According to Andre Els, a former Soekor employee who worked on this site, after reaching a depth of 4000 metres, they lost the drilling fluid that contained compounds such as bentonite, chrome lignosulfonate and caustic soda. Six weeks later, over 30 km away on a farm near Klipplaat, a farmer noticed a discoloration in his borehole. Responding to the complaint, Els visited the farm to inspect. The water contained chrome lignosulfonate. With no possibility for this powerful deflocculant to be naturally occurring nor any other drilling taking place in the area, the drilling fluid had swiftly migrated over 30km and made its way to a water source. The unexplored deep geology of the Karoo briefly made itself known.
Fast-forward around 50 years and you’ll find the same area currently being eyed out for “fracking”, or, to avoid falling into the wordplay trap, more accurately referred to as shale gas extraction.
Why is the correlation between the Soekor wells of yesteryear and today’s applications for unconventional gas extraction important?Meet Professor Gerrit van Tonder, a leading geohydrologist from the UFS Institute for Groundwater Studies who is better known in recent months as the Pro-fracking Professor who did a U-turn. Originally optimistic about shale gas extraction, van Tonder backtracked in June to warn that fracking would severely impact underground water supplies. Together with his doctoral student, Fanie de lange, they looked at the Soekor wells in order to anticipate the outcomes of shale gas extraction in the same region. In the area that Shell, Falcon and Bundu, have applied for drilling rights, there are 14 Soekor holes. Thus far, five of those are leaking fluids to the surface.
How is this possible? Don’t fluids stay put underground the way
well-behaved dinosaur juice should?
Strangely enough it seemed as though few had yet to put two and two together in the fracking debate. To fracture the rock and release the gas, companies would be drilling horizontally at depths of around 3-5 km, using roughly 22 – 26 million litres of water per frack job, tons of fine grain silica sand (declared a “Health Alert” by US government agencies who are warning workers that exposure could lead to silicosis, an incurable lung disease, and the mining of which is a enormous issue in itself) and 60 – 330 tons of chemicals…and here’s the pickle: doing all of that into an artesian basin.
The SA 1/66 Soekor well is a prime example of the latter and a case study of what Van Tonder and de Lange are highlighting. Found on Sjambokkraal, a farm outside Merweville, drilling started on this well in 1966 but, unsuccessful in finding oil at 11 000ft, Soekor closed the well with a large steel tap and moved on.
A few weeks ago, I joined van Tonder to visit and reopen SA 1/66 which is an eyesore on the Karoo veld. The natural vegetation which was cleared for the well pad has never fully restored itself for a large radius around the well. Within seconds after Oom Boetie Botes, the farmer on Sjambokkraal, threw his strength behind the rusty tap, a burst of air shot through the pipe and was followed by lukewarm, grey foul-smelling water. We held a matchstick to the end of the tap and a large flame formed on the water. Judging by the heat of the water and the strength of the flame, the contents spewing out of the pipe emerged from deep below the earth’s surface.
Water samples revealed a salt reading of 8029 ppm for the old Soekor well. While boreholes closer to the farmhouse read 780 and 800 ppm, a borehole situated downstream from the Soekor hole, roughly 1km away, read 5480 ppm. With a salt concentration more than 8 times that of other boreholes further away on the farm, van Tonder is convinced the Soekor well is leaking and impacting the surrounding water source. Working with his students, van Tonder plans on carrying out further water analysis in the area. Thus far, it seems that they are onto something. Remember the aforementioned Skietfontein borehole near Aberdeen? The water well closest to the Soekor borehole has double the salt concentration compared to others on the property and the farmer has complained that his sable get sick when grazing in the fields surrounding the hole.
So, what is the significance behind these revelations? Essentially, the companies who are seeking to exploit possible shale gas reserves in the Karoo have just been dealt another enormous hurdle in any attempt to safely extract gas.
Let us quickly look at all those hurdles.
Here is a quick checklist that outlines how to best avoid contaminating underground water resources upon which the entire Karoo so heavily depends:
- SURFACE SPILLAGE OR EXPOSURE
With the list of additives including chemicals that are capable of contaminating millions of litres of water in minute concentrations and others that are carcinogenic or known to impact the nervous and endocrine system, it would be best to avoid any possibility of these chemicals reaching the ground or being dispersed in the air.
While most of the water remains in the shale, around 30-60% of the fluid returns to the surface once the well has been drilled and fracked. This flowback is laced with the injected chemicals and elements found naturally in the shale: concentrated salts; heavy metals such as lead, arsenic, barium and naturally occurring radioactive materials including uranium, radium and radon. In addition – because there’s always more to the fracking footprint – a triple whammy is formed in a chemical interaction between added chemicals and compounds found in the shale. As nasty to human health as it is complicated to pronounce, 4-nitroquinoline-1-oxide (4-NQO) is one of the most potent carcinogens known to man and while it is not a chemical additive nor a shale resident, it has been discovered in shale flowback fluids.
The effective rehabilitation of this fluid to its original standard has yet to be achieved and companies are still experimenting with possible disposal methods. Thus far, attempts have yet to prove successful. Storing the fluid in enormous open ponds has led to severe health impacts. Sewerage systems are not designed to treat the chemical compounds or radioactive elements. Efforts of injecting the fluid back into the earth immediately reintroduces a major risk of contaminating water sources while this process of deep well injection has induced earthquakes in areas such as Ohio, Oklahoma and Texas.
- ALTERNATIVE UNDERGROUND PATHWAY
No chemicals or hazardous elements found in the rock should find an alternative pathway via a natural fracture in the rock or, a possible curveball unique to the Karoo that the gas industry is yet to encounter elsewhere in the world: the hefty dolerite dykes and sills.
- UNDERGROUND MOVEMENT OF WATER
It would also not be ideal for foreign fluids to wind up catching a surf in the natural horizontal movement of underground water that many geologists, Karoo farmers and the aforementioned, Andre Els, will attest to. The slightest accident on one out of a thousand wells will not be isolated to that area. Unfortunately, according to independent hydrologists, it seems as though reservoir engineers working in the oil and gas industry fail to take this risk into account. According to Professor Shlomo Neuman from the Department of Hydrology and Water Resources at the University of Arizona, one could open any reservoir engineering text and “find nothing about leaky aquifers or cross-formation flow”. Perhaps a reservoir engineer with this departure point contributed to the governmental task team because the Executive Summary Report states that “potable aquifers are expected to be far removed from shale gas target formations and safe from contamination from injected fracking fluids because the latter are immobile under normal conditions”.
Alarmed, I am tempted to say something about the blind leading the blind but I am not going to.
- ARTESIAN AREAS
The artesian geology introduces a further risk of encountering vertical movements of brine to the surface. As was seen on SA1/66, Van Tonder is most concerned about this upward migration once the well is abandoned and pressure increases in the reservoir resulting in the fluid rising toward water sources. By this stage, the company has abandoned the area just as, 44 years after Soekor’s activities, Boetie Botes is left with a barren area around the wellhead and salt concentrations 10 times beyond what is considered safe for human or animal consumption.
- LEAKAGE AROUND THE WELLHEAD
The cement and steel casing around the wellhead, where the borehole meets the surface, needs to be designed and implemented to ensure that no drilling additives, brine or hydrocarbons exit the well – not while drilling or fracking or when producing gas or when the well is declared exhausted and forever abandoned. Current capping technology uses steel that will rust away and concrete that breaks down over time in the same way that roads or bridges do. But, while the latter are maintained and monitored, old oil and gas wells become a forgotten series of ticking time bombs.
According to Dr Ron Bishop, the US Environmental Protection Agency estimates that 1 out of 6 abandoned oil and gas wells are already leaking toxins to the surface. In the wake of the Deepwater Horizon blowout in the Gulf of Mexico, EcoHearth commissioned accomplished journalist Steven Kotler to investigate the extent of the problem on land and across the planet. Kotler found that out of a minimum of 2.5 million abandoned oil and gas wells littering the US and an estimated 20-30 million around the world, due to fatally flawed capping technology and lax industry and government oversight, hundreds and thousands are “hemorrhaging oil, brine and greenhouse gases into the environment”. James Northrup, a former energy investor and planning manager for Atlantic Rich Field, agrees: “All gas wells will eventually rust out and leak; it is not a matter of if, only a matter of when and how much.”When the previous government embarked on the Soekor exploration in the 60s, many probably anticipated considerable reserves, economic prosperity and widespread employment opportunities. Fifty years later the Karoo is left with deteriorating well casings, possible underground water contamination and roads and well pads that have never disappeared in the semi-arid veld.
Would the shale gas industry introduce the same scenario and perhaps even raise the stakes? Would it present a short term energy solution that eventually dissolves into thousands of abandoned wells? Would economic gain and temporary job creation come at the longterm expense – health costs, permanent environmental damage, disruption to local economies and decreasing property values – of those in the Karoo and outlying areas? And outside of groundwater contamination and failed cement casings, what if the shale gas is not a heralded ‘transition fuel’ and merely a distraction from responsibly transitioning to a low carbon future and a threat to the growing concerns of irreversible climate change?
It is of upmost importance that the many governments around the world who are currently considering shale gas extraction adopt this longterm perspective. While global priorities seem focussed on repairing struggling economies and favoring the first venture that touts job creation, we cannot afford to invest in today by sacrificing tomorrow.
Jolynn Minnaar is the director of Unearthed, an upcoming independent feature documentary that investigates the global shale gas boom and the potential plans for gas extraction in South Africa. Committed to thorough research and widespread consultation, Jolynn has interviewed over 400 people on all sides of the fracking debate while filming across South Africa, Canada, the US and UK in order to gain an international perspective on the matter. At the forefront of information on the topic, while the film is in post-production, Jolynn has presented her findings at various meetings both locally and abroad.