Shale and tight gas mining uses huge quantities of chemicals. The fracking industry stresses that fracking fluids are mostly water (around 99%), and that chemical additives make up just a tiny proportion of fracking fluids: typically between 0.5 and 2.0%.
While 0.5 to 2 percent is a small proportion relative to the large volumes of water used, it translates into very large quantities of chemical additives.
Data from the US indicates that a typical 4 million gallon fracking operation uses between 80 tons and 330 tons of chemicals.
The conversion from imperial to metric measurements for Australian relevance is:
- 4 million gallons = 15,151,650 litres of water
- 80 tons = 81,285 kg of chemicals
- 330 tons = 335,295 kg of chemicals
Of course, this calculation assumes a weight to weight conversion. The figures vary if we're converting tons to litres, because a ton is a unit of weight and litre is a unit of volume. To accurately convert between tons and litres, we'd need to know the density of the substance we're trying to convert. Gas companies don't publicly disclose the precise quantities of all the different chemicals used in each frack, which means that arriving at accurate figures is exceedingly difficult.
Using a figure at the low end of the scale of what the industry says it uses per frack, and the amount non-industry sources claim is the truer figure, a low-ball estimate of 15 million litres of water per frack is indicated.
Each frack rams somewhere between 80,000 to 335,000 kgs of chemicals into the earth, a staggering quantity when each well is fracked approximately 10 times. This massive amount of chemicals is what the industry would have us believe is 'tiny'.
In addition to the chemicals used in other types of fracking, tight gas also requires acidation to achieve commercial flow rates. Acidation is the practice of pumping acids into tight gas formations to dissolve the cements between rock grains. Techniques to map out tight gas deposits include exploding dynamite and vibroseis (measuring the vibrations produced with seismic equipment).