As of today, fracking continues to be a topic of interest both here in the U.S. and other countries. My first post on this topic, Fracking and the Geology Behind It, provided the reader with a brief understanding of the earth’s geology and some of those difficult and hard to mine energy sources, e.g. shale gas, that are found below the surface. As shown in the figure below, the U.S. has an abundance of shale gas formations.
According to the Energy Information Administration (EIA), shale gas is found in shale “plays” – shale formations containing significant accumulations of natural gas and that share similar geologic and geographic properties. Until recently, the cost of mining and bringing shale gas to the surface was cost prohibitive, or at best not cost effective.
This post continues the discussion of fracking with the intent of helping the reader better understand the process, related terminology, its evolution and early history. As a reminder, from the last post we learned that shale is an organic rich rock, and shale gas is natural gas that is trapped within this rock.
Fracking is often described as a process of drilling downward and creating tiny explosions to shatter and crack hard shale rocks to release the gas inside. Water, sand and chemicals are injected into the rock at high pressure that allows the gas to flow out to the head of the well. This post provides some general information to ensure that the reader is aware of the different types of activities that are additional information on terminology as well as a short history of the early technology and steps associated with the process.
First, we differentiate between onshore and offshore fracking, then hydraulic and non-hydraulic fracking. Why? Because most of the news that is reported in the media pertains to onshore, hydraulic fracking.
Onshore vs. Offshore Fracking
Fracking takes place both onshore (on land) and offshore (in the ocean). Most of the news about fracking relates to the activities on land. However, offshore fracking has occurred with little attention in sensitive coastal waters where for decades new oil leases have been prohibited. According to the Associated Press and The Huffington Post, regulators have permitted fracking in the Pacific Ocean at least 12 times since the late 1990s, and have recently approved a new project. [Ref 1] Only recently government regulators have begun to question if this practice should require a separate permit and be subject to stricter environmental review?
As an update to the above, Congresswoman Lois Capps (D-California) called for a moratorium on offshore fracking in federal waters on November 19, 2013. [Ref 2] The primary reason was to request a comprehensive study of its environmental and public health impacts. “I have been seriously concerned about offshore fracking since recent reports first brought it to light,” Capps said in a statement. She also stated that many of the drilling activities had been approved with “overly broad and outdated plans” that do not adequately account for the risks.
Many opponents of onshore fracking complain that even less is known of the problems and risks associated with offshore fracking.
Hydraulic vs. Non-hydraulic Fracking
During the hydraulic fracking process, water, chemicals, and sand are pumped into the well to unlock the hydrocarbons trapped in shale formations by opening cracks (fractures) in the rock and allowing natural gas to flow from the shale into the well. When used in conjunction with horizontal drilling, hydraulic fracturing enables gas producers to extract shale gas economically. Without these techniques, natural gas does not flow to the well rapidly, and commercial quantities cannot be produced from shale.
Many opponents of conventional hydraulic fracking complain about the enormous volumes of water that are used in the process and post-extraction issues associated with contaminated water seeping into groundwater. Instead of water, non-hydraulic fracking uses liquefied petroleum gas (LPG), liquid natural gas (LNG), or other non-water mixtures. As an example [Ref 3], Gasfrac of Calgary, Alberta (Canada) fracked its first well in 2008 using LPG or propane gel instead of water.
Early History and Technology
The principles or concepts of fracking date back to the 1800s. Even back then, those in the oil drilling business knew that oil or natural gas was buried below the surface, however, extracting it would prove extremely challenging if the fossil fuels were embedded in rock. Innovation and invention was also not new to those who worked in the business. During the 1860s, it is reported that an experimental solution was created utilizing a person or well shooter to drop an explosive charge down a well. [Ref 4] The idea was to deliver a powerful force at a selected underground depth. In doing so the explosions would rubblize the hard rock formations around the well and release the oil or gas trapped within.
The well shooter’s original tools of choice were gunpowder and, later, liquid nitroglycerin, delivered down the well within an “exploding torpedo” patented by Lt. Col. Edward A. Roberts in 1865-1866 [Ref 4]. He first introduced his technique in the oil fields around the industry’s Titusville, PA, birthplace, and it quickly spread to the surrounding states of New York, West Virginia, Kentucky, and parts of Ohio. Roberts pumped large amounts of water down the well to achieve what he called “superincumbent fluid tamping” to concentrate the power of the explosion as it sent cracks through the formations below.
Needless to say, the practice of fracking was very risky, especially after nitroglycerin replaced gun powder in the process. Putting risks aside, when reports of up to 1,200 percent production increases began to circulate, those engaged in the early petroleum industry took note of Robert’s Torpedo and the company’s coffers increased tremendously!
A Safer Process
While Roberts exploding torpedo gained in popularity, the actual use of it was also a very dangerous proposition with very little room for error or slippery fingers on the part of the well shooter. The idea of non-explosive alternatives to nitroglycerin took root in the 1930s. Experiments through the next decade paved the way for the first industrial-scale commercial uses of the modern patented Hydrafrac process in1949, with Halliburton holding an exclusive license in the early years.
The first fracking experiment was conducted in 1947 and was based on the studies of Floyd Farris at Stanolind Oil and Gas Corporation. [Ref 4,5] The test was conducted at the Hugoton Gas Field in Grant County, Kansas. One thousand gallons of gelled gasoline (or napalm) and sand were injected into gas-producing limestone formation at 2,400 feet. Although the test was not considered very successful, a patent was issued for this process in 1949, and an exclusive license was granted to the Halliburton Oil Well Cementing Company. The first commercial applications of fracking were conducted by Halliburton in 1949.
You will hear more about Halliburton in the next two posts on this topic. However, before closing out this discussion, you will be interested to know that in the early years of fracking, a typical process included the use of 750 gallons of fluid (water, gelled crude oil, or gelled kerosene) and 400 pounds of sand, and the average power needed to pump the fracking materials was about 75 hydraulic horsepower (hhp). [Ref 4]
According to MacRae, modern methods can use up to 8 million gallons of water and 75,000 to 320,000 pounds of sand. Fracking fluids can take the form of foams, gels, or slickwater combinations and often include benzene, hydrochloric acid, friction reducers, guar gum, biocides, and diesel fuel. Likewise, the power needed to pump fracking material has risen average of more than 1,500 hhp today, with big jobs requiring more than 10,000 hhp.
The large volumes of water and chemicals used in the process have drawn much criticism from the opponents of the fracking process.
- Offshore Fracking Off California Coast Under Review, Drawing Calls For Increased Regulation, Associated Press, Jason Dearen and Alicia Chang, August 3, 2013, http://www.huffingtonpost.com/2013/08/03/offshore-fracking_n_3700574.html
- California Congresswoman Seeks Offshore Fracking Moratorium, Jared Gilmour, The Huffington Post,
- Fracking Study Finds Methane Emissions Lower Than EPA Estimates, by EDI Editors, September 17, 2013, http://www.ediweekly.com/tag/hydraulic-fracturing/
- Fracking: A Look Back, by Michael MacRae, ASME, December 2012, https://www.asme.org/engineering-topics/articles/fossil-power/fracking-a-look-back
- Fracking, www.wikipedia.org