Tom Giesen writes in a guest column for Informed Comment:
As our stocks of cheap and easy gas and oil diminish, we seek oil in remote places – in rock formations 10,000’ below the surface of the Gulf of Mexico; in the Arctic; and held in essentially impermeable geologic formations.
Those impermeable geologic formations are often suffused with oil and/or gas, but the oil or gas is largely unavailable because the pores in the formations are too small to allow gas or oil to move freely. To access it, wells are drilled into oil or gas-bearing formations and then turned to run horizontally, following the hydrocarbon-laden layer. “Fracking” works via high pressure hydraulic shocks to the formation, creating fractures and voids into which the oil and/or gas collects. Water use is huge – over 5 million gallons are needed per well. After the hydraulic fluids have done their work, they are slowly brought back to the wellhead, and a lot of gas (or oil) comes up with the polluted water. The gas is either vented or flared off (burned), as separation and collection is difficult until the fracking fluids are all out.
Fracking is very complex and expensive, and fracked oil and gas wells have short lives. Production declines by 80 or 90% in just three years. To maintain production, new wells must be drilled every two years or so – drilling and fracking are essentially continuous.
Fracking causes multiple problems. Methane leakage to the atmosphere occurs during well drilling and completion, and especially during hydraulic fluid removal (“flowback”). Fracking is associated with small earthquakes, and with domestic water supplies contaminated by methane. Fracking water is made toxic by fracking fluids, and it is disposed of by just pumping it underground or otherwise wasting it. The chemicals used in fracking are believed to be cancer-causing, but the industry is exempt from full disclosure – chemicals used are “trade secrets”! Fracking was exempted from the Safe Drinking Water Act in the Bush administration.
While a recent study (Allen et al. 2013) claimed that methane emissions at fracked wells were very low, that study was shown to be inadequate and misleading.
Many countries have looked into this technology and, alarmed, have banned it or declared a moratorium, including France, Germany, and South Africa.
Fracking is profitable only because it has multiple exemptions from relevant environmental laws. It is clearly an unsustainable practice, and should be banned.