Fracking is a stimulation process used to extract natural gas (and in some cases oil) from deep reserves in various rock formations below the surface. This process allows energy companies to extract natural gas and oil that was not previously attainable. The fracking process involves pumping a mixture of water, sand and chemicals into a well at a high pressure, which fractures the surrounding rock formation and opens passages and allows the gas and oil to flow more freely. Once the well is developed, some of the fracking fluid is carried back to the surface with the gas and oil, while the rest remains in the ground.
The force of the water creates a network of tiny fissures in the impermeable rock. The flow of the water forces the sand mixture into these cracks, which then holds them open to allow natural gas or oil to flow through. The average fracturing process takes 3 to 10 days to complete.
History of Fracking
The process of fracking was first discovered in the year 1866, by a Civil War veteran named Edward Roberts. Roberts observed artillery rounds during the war and came up with the idea of creating a concentrated explosion inside of an oil well in Titusville, Pennsylvania. During this process, a "Roberts Torpedo" was lowered into the well to the spot where it was thought it should be exploded. The purpose of this was to fill the borehole with water in order to fracture the oil strata. The technique was extremely successful, and production from the initial wells increased by over 1,000 percent shortly after the wells were "shot." By 1868, nitroglycerin began to be used in place of black powder.
In the 1930s, injecting a non-explosive fluid was attempted, which involved the injection of an acid substance to "acid etch" the rock strata. This process was combined with water injection and was confirmed to be successful in several drilling operations. In 1939, Ira McCullough developed a variation on Roberts's idea. His method consisted of a bullet-shot casing perforator, which sent projectiles through the casing and into the oil formation, also with the intention of fracturing the strata. This greatly enhanced the flow of oil through the well. Soon after, Floyd Farris from Stanolind Oil and Gas Corporation conceived the idea of hydraulically fracturing the formation to enhance the production in their wells. By 1949, the first commercial application of hydraulic fracturing was realized on an oil well in Duncan, Oklahoma. Fracking became the most commonly used method of stimulating wells. The technique was patented by the Pan American Oil Company, and a license was issued to the Halliburton Exploration and Production Company to use the technique in their oil drilling operations. In 1953, the license was extended to other drilling companies.
In the 1970s and 1980s, George Mitchell, owner of Mitchell Energy & Development, applied the fracturing process to the Barnett Shale in Texas, which began the current wave of shale productivity that has lasted to the present day. It was Mitchell's idea to manipulate the naturally occurring fractures in shale formations in order to allow the gas to flow more easily. Mitchell drilled the first horizontal wells and received tax credits through Section 29 of the Internal Revenue Code from the federal government in order to subsidize further well projects.
Since then, hydraulic fracturing has led to increased production from underperforming oil and gas wells. The Environmental Protection Agency (EPA) calls the process of hydraulic fracturing a well-stimulation process, which best describes the use of fracturing for wells which would otherwise be unable to produce further.
Fracking was not used on a large commercial scale until 2003, when companies began exploring natural gas reserves within the shale formations found in states such as Texas, Pennsylvania, West Virginia, Wyoming, Utah and Maryland. Hydraulic fracturing was exempted from regulation (for the most part) under the Safe Water Drinking Act in the Energy Policy Act of 2005 [PDF]. The only regulation of hydraulic fracturing found in the Act is the use of diesel fuels as part of the fracking fluid.
Currently, about 90 percent of wells in operation have been fractured, including in unconventional formations. The majority of current debates over hydraulic fracturing surround the issue of fracturing fluids. After the fracturing is completed, the fracturing fluids can be brought back to the surface; the current methods of disposal are underground injection or discharge into surface water (once properly treated). The surface waters discharged are regulated by the National Pollutant Discharge Elimination System (NPDES). Treatment for this water is done via wastewater treatment facilities.
Although California and Texas oil drillers have been using fracking in their operations for decades, hydraulic fracturing has never before received the same level of media and legislative attention as it has in New York, Ohio and Pennsylvania. Controversial issues include the treatment and disposal of fracking fluid; the possible mismanagement (such as spills, leaks, etc.) of fracking fluid; and how the process of fracturing the rock strata may create small earthquakes, which, according to the US Energy Information Administration, are almost always too small to be a safety concern.