Hydraulic Fracturing
Hydraulic Fracturing, or fracking, is a well completion process that is different than brine injection.
Fracking is used in wells intended to produce gas and oil. After the well is drilled, fracking fluid is injected under pressure down into the well and out into the shale zone through holes drilled in the casing. The fluid is mostly made up of salt and water, and a small percentage is chemical additives.
The forced injection is intended to fracture the shale, and the cavities created will fill with gas or oil, which can then be pumped to the surface.
Brine Injection
Brine is mostly fracking fluid that is left from the fracking process. When a well is fracked, 15 to 20 percent of the water used in the process returns to the surface. This water then is either treated and discharged or it's injected deep into the earth for permanent storage in an injection well.
Injection wells are vertical wells drilled down to a level of porous sandstone. The process is to inject the brine under pressure where it will be forced into the porous sandstone and slowly spread away from the well allowing room for the next injection.
Brine injection is not fracking, but used fracking fluid is a large component of brine.
For more information on the hydraulic fracturing process,
click here. For more information on injection wells,
click here.
