What is hydraulic fracturing (fraccing)?
Fraccing involves stimulating fractures in a rock layer in order to increase the flow of gas or oil.
Fluid is pumped down the well at high pressure to produce tiny cracks in the target rock reservoir.
The well is cased in steel and concrete so that the fluid enters only the target zone. “Proppants”, such as sand or tiny ceramic beads, in the fluid are used to hold the fissures open and improve the flow of gas or oil.
The injected fluid is typically more than 99% water and sand plus a very small amount of chemicals. The chemicals are needed to reduce friction, remove bacteria, dissolve some minerals and enhance the fluid’s ability to transport sand.
Chemicals used in Australian fraccing operations include sodium hypochlorite and hydrochloric acid (both used in swimming pools), cellulose (used to make paper), acetic acid (the active part of vinegar) and small amounts of disinfectants.