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.
Artesian basins are formed when underground water is stored under
pressure and if drilled into, wells would naturally produce an upward
flow of fluid. In some cases you find a luxurious natural hot spring
like those in Calitzdorp or Aliwal North, in other cases, the rising
water would be unfit for human, animal or plant consumption because it
contains high salt concentrations and possible heavy metal or
radioactive elements inherent in the deep rock.
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.
Household water containing glutaraldehyde, a powerful biocide used in drilling operations in Pennsylvania.
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.
- 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.
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.
Remnants of Soekor activity on Skietfontein outside Aberdeen.
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.
