Fracking, also known as hydraulic fracturing, is a drilling technique used to extract natural gas or petroleum (oil) from thousands of feet beneath the Earth’s surface. It involves creating fractures or cracks in and below the Earth’s surface by injecting a high-pressure mixture of water, chemicals, and sand into a wellbore. This process allows the release and extraction of natural gas or oil trapped in rock formations, particularly in shale rock. Natural gas producers can dig previously untapped sources when combined with another technology known as horizontal drilling.
The fracking process typically begins with the drilling of a wellbore vertically into the ground. Once the desired depth is reached, the wellbore is then turned horizontally, extending through the gas or oil-bearing formation. This horizontal section is perforated, and then a fluid mixture, known as fracking fluid, is pumped into the well at high pressure.
The fracking fluid is primarily composed of water, but it also contains various chemical additives to enhance the extraction process. These additives can include substances like gels to increase fluid viscosity, acids to remove debris from the wellbore, biocides to prevent bacterial growth, surfactants to make the water slick, and scale inhibitors. The fluid also contains proppants, usually sand or ceramic particles, which help keep the fractures open once the pressure is released.
When the fracking fluid is injected into the well, it creates fractures in the surrounding rock, allowing the trapped natural gas or oil to flow more freely. The proppants hold the fractures open, enabling the gas or oil to flow through them and into the wellbore. The mixture of released gas or oil, along with some of the fracking fluid and naturally occurring subsurface salts and compounds, is then brought to the surface.
The Fracking Industry in Pennsylvania
Pennsylvania’s Department of Environmental Protection is promoting the use of tainted water coming from hundreds of abandoned coal mines for hydraulic fracturing, or fracking, the industrial process that has propelled the state to the forefront of natural gas production. A white paper was issued in January outlining how acid mine drainage (AMD), or metal- and salt-laden water, can be treated and subsequently exploited as a source of fracking water. The state intends to achieve a twofold benefit by reducing the flow of tainted water from mines into rivers and reducing the amount of freshwater required in fracking.
Pennsylvania, long a top energy-producing state due to coal and oil, is now riding the natural gas wave. The state’s Marcellus shale formation has become an energy jackpot because of directional drilling. This maintains a well within the gas-bearing shale layer, and fracking, which blasts a mixture of water, sand, and chemicals to split the rock and extract the gas. Since 2008, the state’s gas production has more than tenfold increased, propelling it from 14th to sixth in the nation. At the same time, shale gas’s coronation has been tainted by widespread concern about the possible harm to the environment and human health from the procedures used to extract it and the act of burning it as a fuel.
The industry coined “fracking,” which refers to a particular oil and gas extraction stage. However, due to the increased media attention encompassing the country’s oil and gas boom, the word fracking is often considered connected to all that is linked to the exploration and extraction of these resources, like the building of good pads and all the associated work necessary for supporting the industry, including building pipelines and truck traffic.
Fracking Operations and Costs
Fracking and horizontal drilling have increased domestic oil and gas production. Horizontal drilling enables a single surface well to tap gas trapped across hundreds of acres. When a standard vertical drill strikes a shale rock, it rotates horizontally. Drilling can then occur in multiple directions, similar to the spokes of a wheel. The well is encased in steel and cement to prevent gas and frack water from spilling out. To perforate the steel casing, explosives are put at regular intervals throughout the horizontal part of the well. These openings permit gas trapped in restricted strata to travel up the well’s vertical section.
Under extreme pressure, a mixture of water, sand, and chemicals is injected deep into the Earth, causing cracks and fissures in the shale rock. The sand opens the notches, allowing natural gas to flow through the fractures, into the well bore, and up to the surface. The wastewater is polluted with some compounds, subsurface salts, and naturally existing radioactive substances. That wastewater must be treated or buried deep underground using injection wells.
Requirements of Fracking a well
Fracking a well can cost between $3 and $5 million. Land must be cleared, levelled, and readied for a good pad before a well may be fracked. Each wellhead requires approximately 5 acres. Although a wellhead may be located on a single leased piece of property, gas extraction may occur beneath the land of multiple property owners. Drill mud and drill cuttings are produced during the initial drilling process. Some soil can be reused, but the cuttings must often be disposed of.
After a well has been cased and cemented, a separate team arrives to frack the well, which involves several stages. These include perforation of the horizontal section, administration of forced frack water, connecting that region of the well, and continuing to the next section. To keep the fractures open, the frack water contains a proppant, usually sand. It also has chemical additions, which are the most contentious elements. Gels to increase viscosity, acids to remove muck from the wellbore, biocides to kill bacteria, surfactants to make the water slick, and scale inhibitors are among the additives.
Environmental and Health Impacts
The industry is exempt from the Safe Drinking Water Act and is not required to declare the chemicals it uses. Critics argue these chemicals could pollute water supplies via surface spills or leaks from poorly constructed wells. Once the well begins producing, not all frack water moves back to the surface. Some are concerned that even frack water left over a mile underground may migrate and pollute water supplies over time.
The Endocrine Disruption Exchange has produced a website with information on drilling chemical exposure’s health and environmental effects. The safety of hydraulic fracturing is being debated. According to industry and certain elected authorities, fracking chemicals have never contaminated water systems. Although cases of methane migration due to poor casing construction have been confirmed, the industry frequently claims methane was present in drinking water before drilling. And according to them, methane migration is not caused by “fracking.”
Aside from water contamination, some people are concerned about the water required to frack a well. Here are the overall environmental and health implications of hydraulic fracturing:
Well-pad building in rural communities increases traffic, noise, and air pollution.
Drilling requires tremendous water and chemical additives, which must be processed and disposed of when recovered as flow back water.
Flow back water is stored in on-site ponds, impoundments, and above-ground tanks.
Air pollution is caused by compressor stations and recovered oil and gas flaring.
Fracking can cause minor earthquakes along fault lines due to the injection of fluids into the ground. However, the primary source of earthquake concern has been the disposal of used frack water in deep injection wells.
Large amounts of sand are extracted during the hydraulic fracturing and transported to hydraulic fracturing sites for drilling operations.
The Bottom Line
Fracking has revolutionized the energy industry by enabling the extraction of natural gas and oil from previously inaccessible reserves. However, it has also sparked significant debate and concerns due to potential environmental and health impacts. The media has focused heavily on hydraulic fracturing. The complex process of extracting oil and gas from shale rock formations includes multiple potential human exposure pathways.
Regulations and oversight of fracking practices vary by region and country. Some jurisdictions require disclosure of the chemicals used in fracking fluid, while others may exempt the industry from certain environmental regulations. Ongoing research and monitoring are essential to understand better and mitigate the potential risks associated with fracking and hydraulic fracturing.