It’s a controversial subject at best, but there may be solid reasons to regulate hydraulic fracturing, or fracking, in areas like the Marcellus Shale site. In addition to the numerous other environmental concerns, such as the unknown chemicals seeping into groundwater supplies, the concentration of radionuclides in the water, pipes, and equipment of a fracking site present a danger to workers and local residents.
The process of extraction of natural gas from black shale has been around a long time, but public concern has increased in recent years. Both public and private figures are calling for stricter regulations on hydraulic fracturing, also known as hydro-fracking. In states that allow this process, there have been cases of environmental pollution, including: contaminated ground water and increased levels of illness. In addition, the companies may provide no plan for efficient waste handling or accident mitigation, and potentially-harmful concentrations of radioactivity are released into the environment.
The Marcellus Shale site is located in the north-eastern region of the United States. This area spans underground from Ohio and West Virginia northeast into Pennsylvania and southern New York. Small areas of gas-shale also exist in areas of Maryland, Kentucky, Tennessee and Virginia.
Marcellus is a black shale with a detectable radioactive signature, which has become a major natural gas supplier, referred to as a super gas field. Low density, and organically rich, the depth spans to more than a mile below the earth’s surface. Recent estimates put the natural gas potential at 500 trillion cubic feet. A comparison for just how large this is; New York uses about 1.1 trillion cubic feet of gas per year. With new technology for fracking and the construction of a pipeline, interest in exploiting this resource has increased dramatically.
Hydraulic Fracturing: Chemistry of Fracking
The basis for this process is horizontal drilling. A vertical well is drilled down to the appropriate depth, containing the gas-containing shale, and then is curved horizontally within the subject rock.
Providing maximum exposure to the gas-bearing rocks, a solution of water, sand, and chemicals are pumped through the shale at high pressure to create fracturing in the rock. This process releases the gas. The proprietary chemicals used in this process might include: a biocide, gel, friction reducer, other agents to prevent corrosion of the pipes, and a material such as sand, to keep the fracture open for gas release.
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