What is Hydraulic Fracturing

What is Hydraulic Fracturing?

Hydraulic Fracturing, or more commonly known as fracking, is a method of underground well stimulation that is used to extract underground resource deposits such as oil, water, and natural gas.  Gas and oil companies use fracking because it is currently the most time and cost efficient way to draw natural gas from the deep shale rock formations underground.  There has been a recent boom of natural gas production in Pennsylvania with the development of hydraulic fracturing technology as well as the discovery of the Marcellus Shale formation ranging from West Virginia to Western New York State.

What is the Natural Gas Extraction Process?

The first step in natural gas production is the identification of underground rock formations containing natural gas deposits.  Following the identification of available resources is the land acquisition process.  If the target land is vacant the industry is likely to purchase the land for drilling.  If the land is occupied the drilling company will offer royalties to the owner of the property.  Land Lease holders have not been known to receive more than a small fraction of the overall production of shale gas wells.  From the purchase or lease of surface land above natural gas deposits gas and oil companies initiate the well drilling process.

Site construction begins with the leveling of the environment surrounding the well.  Not only is the drill site leveled but there is the clearing of trees and development of the infrastructure required for the heavy truck traffic that occurs during hydraulic fracturing operations.  The wells drilled often travel hundreds to thousands of feet vertically and then, depending on the scale of resource deposits, up to a mile or more horizontally.

Well Casings

In order to protect drinking water sources there are a series of well casings installed in the first few hundred feet below the surface.  The well casings are layers of cement and steel implemented with the purpose of shielding fragile aquifers that may lie between the surface and the underground resource deposits.  Following the installation of well casings is the high pressure fracturing of rock formations with millions of gallons of water and thousands of gallons of chemicals.

EPA: Hydraulic Fracturing

“Fluids, commonly made of of water and chemical additives, are pumped into a geologic formation at high pressure during hydraulic fracturing.  When the pressure exceeds the rock strength, the fluids open or enlarge fractures that can extend several hundred feed away from the well.  After the fractures are created, a propping agent is pumped into the fractures to keep them from closing when the pumping pressure is released.  After fracturing is completed, the internal pressure of the geologic formation cause the injected fracturing fluids to rise to the surface where it may be stored in tanks or pits prior to disposal or recycling.  Recovered fracturing fluids are referred to as flow-back fluid.  Disposal options for flow-back fluid include discharge into surface water or underground injection.”

American Petroleum Institute: Hydraulic Fracturing

“Hydraulic fracturing is a proven technology used safely for more than 60 years in more than a million wells. It uses water pressure to create fissures in deep underground shale formations that allow oil and natural gas to flow.  First used in the U.S. in 1947, the technology has been continuously improved upon since that time.  Recent innovations combining this technology with horizontal drilling in shale formations has unlocked vast new supplies of natural gas, allowing the nation to get to the energy it needs today, and transforming our energy future.”

TEDX Natural Gas Drilling Operations from a Human Health Perspective

“The technology to recover natural gas depends on undisclosed types and amounts of toxic chemicals. A list of 944 products containing 632 chemicals used during natural gas operations was compiled. Literature searches were conducted to determine potential health effects of the 353 chemicals identified by Chemical Abstract Service (CAS) numbers. More than 75% of the chemicals could affect the skin, eyes, and other sensory organs, and the respiratory and gastrointestinal systems. Approximately 40-50% could affect the brain/nervous system, immune and cardiovascular systems, and the kidneys; 37% could affect the endocrine system; and 25% could cause cancer and mutations. These results indicate that many chemicals used during the fracturing and drilling stages of gas operations may have long-term health effects that are not immediately expressed. In addition, an example was provided of waste evaporation pit residuals that contained numerous chemicals on the CERCLA and EPCRA lists of hazardous substances. The discussion highlights the difficulty of developing effective water quality monitoring programs. To protect public health we recommend full disclosure of the contents of all products, extensive air and water monitoring, coordinated environmental/human health studies, and regulation of fracturing under the U.S. Safe Drinking Water Act.”