Hydraulic fracturing is a proven technological advancement that allows natural gas and oil producers to safely recover natural gas and oil from deep shale formations. This technique has been used by the industry since the 1940s. Today, hydraulic fracturing is used in nearly all natural gas wells drilled in the United States. Most importantly, it has the capacity to significantly reduce our dependence on foreign fuel imports.
Hydraulic fracturing stimulates production from new and existing oil and gas wells. Through use of fluid and material we create or restore small fractures in a formation. This creates paths that increase the rate at which fluids can be produced from the reservoir formations, in some cases by many hundreds of percent.
It is not a “drilling process.” Hydraulic fracturing is a technique used after the drilled hole is completed. The process includes thorough steps to protect water supplies.
Steel surface or intermediate casings are inserted deep into the well between 1,000 and 4,000 feet. This incredibly protective safeguard ensures neither the fluid that will eventually be pumped through the well, nor the oil or gas that will be collected, enters the water supply.
The annulus – which is the space between these casing “strings” and the drilled hole – is filled with cement. Once the cement has set, drilling continues from the surface bottom or intermediate cemented steel casing to the next depth. The process is repeated, using smaller steel casing each time, until the oil and gas-bearing reservoir is accessed (generally 6,000 to 10,000 ft). A more detailed look at casing and its role in groundwater protection is available HERE.
With these and other precautions taken, high volumes of fracturing fluids are pumped deep into the well at pressures sufficient to create or restore the small fractures in the reservoir rock needed to make production possible.