Hydraulic fracturing, or “fracking”, has been used since the 1950s to stimulate oil and gas wells. The process involves pumping a sand-laden slurry into a well and subjecting it to enough pressure that the rocks in the productive formation fracture, or break. The purpose of the sand is to prop open the fracture, so it stays in place. The carrying fluid can then flow back out of the well, along with oil and gas if it’s been a successful frac. The technique of hydraulic fracturing is used to increase or restore the rate at which fluids, such as oil, gas or water, can be produced from a reservoir, including unconventional reservoirs such as shale rock or coal beds.
Hydraulic fracturing enables the production of natural gas and oil from rock formations deep below the earth’s surface (generally 5,000-20,000 feet or 1,500-6,100 m). At such depth, there may not be sufficient porosity and permeability to allow natural gas and oil to flow from the rock into the wellbore at economic rates. For example, creating conductive fractures in the rock is essential to produce gas from shale reservoirs because of the extremely low natural permeability of shale. The fracture provides a conductive path connecting a larger area of the reservoir to the well, thereby increasing the area from which natural gas and liquids can be recovered from the targeted formation.
The key risks and impacts of shale gas and shale gas processes and development can be divided as follows: contamination of groundwater by fracturing fluids/mobilised contaminants arising from wellbore/casing failure; and/or subsurface migration; pollution of land and surface water (and potentially groundwater via surface route) arising from:o spillage of fracturing additives; and spillage/tank rupture/storm water overflow from liquid waste storage, lagoons/pits containing cuttings/drilling mud or flowback water. water consumption/abstraction; waste water treatment; land and landscape impacts; impacts arising during construction: noise/light pollution during well drilling/completion; flaring/venting; and local traffic impacts.
Plains for Camdeboo, part of the vast Karoo hinterland, where dinosaurs once roamed, are under threat. 200 000 Square kilometres, a massive 15% of South Africa’s total land mass, is up for grabs for exploration to extract natural gas, trapped in the shale formation of the Karoo basin.Behind the plans – three oil companies: Royal Dutch Shell, Falcon Oil and Gas and Bundu Oil & Gas. Karoo residents are angry. They may own their land, but according to South African law they don’t own the minerals that lie beneath them.
Hydraulic fracturing – ‘fracking’ – is a mining technique developed in the United States which releases natural gas trapped in shale. These pictures show horizontal drilling in the United States. It allows the shale layer to be penetrated for kilometres underground. Underground explosions then fracture the shale, and by injecting water, sand and highly toxic chemicals at high pressure, gas is released. But it’s a controversial method of mining and has major environmental side effects, still under investigation in the US.
“The hydraulic fracturing process has to be done on a very large scale. It takes upwards of 25 million litres of water and chemicals to perform this hydraulic fracturing process. That 25 million litres of water is for one well – there could be many wells… 6, 8, 10, 12, 16 wells drilled from one spot.”
Just one hydraulic fracture uses the same amount of water as the town of Graaff-Reinet would use in about three days. But water consumption isn’t the only issue in this arid region: fracking chemicals are also very toxic, and not all of them can be brought to the surface and safely disposed of. Thousands of wells over a very short time… the probability of there being accidental spills, leaks from pipelines, leaks from valves, breakage in compressor stations, overturned trucks, leaking tanks, all these things happen. Those spills can lead to contamination of surface waters.This dam, which is the main source of water supply for the town of Graaff-Reinet, has been known to empty in times of severe drought. So, it is not just the farmers who depend on the underground aquifers – it is also the towns.” Shell has proposed using seawater, or brackish water from aquifers, as one of the ways of addressing this massive water requirement.One cannot directly use seawater in hydraulic fracturing because – it is too salty. It does not work well with the other chemicals that have to be added to the water for the hydraulic fracturing process to work. It’s quite possible that the toxic fracking water left in the shale could contaminate the surface aquifers. And worse: there is no legislation currently that regulates fracking.
Graaff-Reinet lawyer Derek Light represents farmers in the area, including Princess Irene and billionaire Johann Rupert, and a growing number of interested parties. He successfully opposed the last two exploration applications by Bundu Oil & Gas and says the legal process is failing us. Applicants have 120 days to inform and consult the public and come up with an Environmental Management Plan for a technique no-one fully understands. But the public, spread out on isolated Karoo farms, have only 30 days to respond. He says none of the three companies is giving the public the full facts.
If you can envision over a relatively large area thousands of wells – each of which has its own pipeline going to some central location… roads, pipelines, compressor stations, noise, dust, air pollution, light pollution, noise pollution… you have to get used to it and accept it, or not.
We know they will take all the precautions to do their utmost not to pollute the water and not to pollute the earth, but there is always a risk. And we have seen in the Gulf of Mexico and we have seen in Nigeria. American environmental health analyst, Dr Theo Colburn, says in this US documentary that most chemicals used in fracking fluid are harmful, causing a myriad of disorders.