The Future of Hydraulic Fracturing

As today’s technologies expand and new ideas turn to innovation, disagreements arise. Hydraulic fracturing is a breakthrough in petroleum engineering and the method of fracking is not an exception to disagreements. How much do we know of this technology and what does the future of this innovation have in store for the world? Hydraulic fracturing, or “fracking,” is a topic that has risen to popularity over the past year. Many people outside of the petroleum industry and green community have yet to hear about this breakthrough in technology, although it has been around for approximately 70 years. The rise of new technologies has been a regulatory focus for discussion, and as with new inventions people can either accept the change, or condemn it.

To understand the debate hydraulic fracturing has brought forth, one must understand the process of fracking first. Contrary to popular belief, hydraulic fracturing is not a drilling process, but occurs after a hole is already drilled into the earth. A petroleum engineer then begins the process by sending down hundreds of gallons of water, sand, and fracking chemicals down that hole in order to create tiny fractures in the reservoir. This is achieved by systematically fracturing the rock in many small sections along the horizontal portion of the drilled hole. The tiny fractures allow the petroleum or natural gas to flow freely back up out of the well. In some cases, fracking can increase the flow rate up to hundreds of percent. To put into perspective of the depths at which these wells are drilled, the reservoir bodies are usually located at depths of 6,000-10,000 feet below the earth’s surface. Figure 1[1] (presented below) shows a representation using the Empire State Buildings as a reference for the depth of the reservoir site. In order to protect water supplies, steel casings are inserted up to 4,000 feet below the earth’s surface. As shown in Figure 1, this is to protect the aquifer, which is located approximately up to 1,000 feet below the earth’s surface. Water and sand make up 98 to 99.5 percent of the fluid used in hydraulic fracturing. The 2 to 0.5 percent remaining in the fracturing fluid is the chemical additives used and this is what makes fracking controversial. Due to patents in the industry, not all of the additives are released to the public and this is what concerns the green community. Opposition to fracking has been considerable to environmentalists and Europe in particular, with many countries banning the practice.

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Figure 1[1] shows the depths of the reservoir in comparison to the Empire State Building, which is 1,454 feet tall. As shown, there are approximately seven buildings from the earth’s surface to the reservoir. The water table can be seen at a depth of less than one Empire State Building. This is significant to the petroleum engineer’s argument against the environmentalists concerns of fracking fluid slipping into the aquifer and possibly contaminating it.
Many people in the green community are concerned about the practice of fracking, particularly because of the amount of resources required to complete a fracking job and the potential harm it can bring to the earth. Each fracturing job requires anywhere from 4-8 million gallons of water. This water is often transported by trucks, which deliver the water to the well site. The water is then treated with approximately 40,000 gallons of a specific mixture of chemicals used for extracting the oil or natural gas. The chemicals serve the purpose of preventing bacteria build up. The major concern with fracking is the concern that these potentially harmful chemicals pass the water table when going in and out of the well. Many would argue that the risk of contaminating a location is too great to justify the recovery of the oil or natural gas. Well sites are often located on private property and if the petroleum engineers do not adequately complete their job, the land that they are occupying could be contaminated, affecting the owners of the land and the location where a spill occurs. Spills of fracturing chemicals during transportation have been recorded and led to environmental impacts such as fish dying, as well as soil and irrigation ditch contamination. Only 30 to 50 percent of the fracturing fluid is recovered, while the rest is left in the ground. The waste fluid is subject to evaporate, releasing compounds into the atmosphere and potentially contaminating the ground level ozone. This can contribute to global climate change due to the natural gas containing carbon dioxide that is released during methane burning. With the new fracking technologies, more gas is being extracted, thus contributing to more climate change than previous extractions.

Oil companies have come under much scrutiny in recent history, resulting in laws and restrictions for hydraulic fracturing getting stricter. Oil companies invest millions of dollars to find the technology necessary to recover large portions of the fracturing chemicals used. Specifications for well drilling require thicker walls for the tops of the wells, making it harder for chemicals to contaminate the environment, should a failure occur. Disposal of fracking fluid has often come under fire since the current practice is to leave much of it behind, which could lead to potential harm to the environment. To compensate for this scrutiny, oil companies have been releasing more information about what chemicals are used in the fracturing liquid. There are 12 main chemicals, however, due to the specific requirements of each area, not all 12 are used at a time. Many different combinations of fracturing fluid are used for each well site that allows fracturing to occur. Despite the precautions the petroleum field has taken, and money spent to insure the well-being of the environment and drilling process, there will always be opposition to new technologies. Time will tell if the benefits of hydraulic fracturing will be the future of petroleum engineering.

References

  1. G. Baker, Hydraulic fracturing: the process.

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