Diesel fuel fracking—fracturing rock formations with a fluid containing diesel—has a long history in the oil and gas industry. The first frack job actually did not involve fluid of any kind. Instead, it involved explosives. Oil and gas bearing formations were first fractured by dropping explosives down a wellbore. The first “fracking” patent was issued to Lt. Col. Edward Roberts in 1865 for the “Roberts Torpedo”—literally an iron torpedo filled with 15-20 pounds of gunpowder and designed to explode when dropped down a well4. Soon after, nitroglycerin joined gunpowder as a major player in the fracking industry4.
In comparison, when drillers first began to experiment with fluid fracturing, gelled petroleum and diesel fuels were seen as pretty safe options. However, modern fracking is done with over 90% water, making diesel fuel fracking now seem like a risky business. In today’s atmosphere of environmental scrutiny, diesel fuel fracking has become a source of contention and regulatory debate.
Diesel fuel fracking: a regulatory debate
While diesel fuel is not a major component of modern fracking fluids, its use was further discouraged with the implementation of the 2005 Energy Policy Act. The Act has since become infamous due to its creation of the “Halliburton Loophole”. The language known as the “Halliburton Loophole” essentially exempts fracking from EPA regulation under the Safe Drinking Water Act—unless that fracking involves diesel. According to the 2005 Energy Policy Act, the Safe Drinking Water Act
(i) the underground injection of natural gas for purposes of storage; and
(ii) the underground injection of fluids or propping agents(other than diesel fuels) pursuant to hydraulic fracturing operations related to oil, gas, or geothermal production activities.
This “exemption to the exemption” incentivizes diesel-free fracking by allowing companies to duck federal regulation as long as they don’t use diesel.
Around the same time, federal government under the Bush administration took a second step to curb diesel fuel fracking in the United States. The administration signed a voluntary agreement with the three largest contractors in the country, who then performed 95% of all fracturing jobs in the nation. Halliburton, Schlumberger, and BJ Services (now owned by Baker Hughes) all committed to stop adding diesel to the fracking fluid used to extract coalbed methane5. Diesel fuel fracking in coalbeds was of particular concern due to their proximity to freshwater aquifers.
However, despite these measures, Representative Henry Waxman of the House Energy and Commerce Committee made news in early 2011 when he announced that a congressional investigation had uncovered illegal diesel fuel fracking5. Waxman reported that drilling companies including Halliburton, Schlumberger, and BJ Services had injected around 32 million gallons of diesel fuel into the ground between 2005 and 2009 without notifying the EPA3. Waxman and the democratic investigation committee accused the companies of violation of both EPA authority as well as their voluntary agreement.
While the case against industry seemed fairly clear, the three operators in question argued that they had not overstepped any legal bounds. Representatives of Halliburton emphasized the fact that they had agreed not to use diesel in coalbed fracking but were free to use it elsewhere at their own discretion5. As a result, industry criticized Waxman’s report as overblown and alarmist.
‘While Waxman focuses attention on the volumes of diesel fuels that may have been used in this unregulated period, he fails to report that no incidents of groundwater contamination have been reported — with or without diesel fuels being used,’ said Lee Fuller, executive director of Energy in Depth.5
Furthermore, industry argued that while the 2005 Energy Policy Act gave the EPA the authority to regulate diesel fuel fracking, they had not actually taken any action or implemented any legislation to do so. In response, the EPA quickly entered into the drafting phase of a set of guidelines and procedures for permitting diesel fuel fracking1. Currently, the EPA has published a final draft of these guidelines, signaling that the federal government plans to take the lead in diesel regulation rather than leaving restrictions and permitting up to the states.
While environmental groups continue to push for prosecution of what they see as illegal diesel use, the impact and significance of diesel fuel fracking is still a subject of debate.
What are the concerns with diesel fracking?
Concerns associated with diesel fuel fracking are two-fold. First, diesel fuel is flammable. There is concern that its addition to fracking fluid could cause increased risk of accidental fires and explosions, making for unsafe conditions at fracking sites.
A more prominent fear is that of BTEX chemicals and water contamination. The acronym BTEX refers to several organic chemicals with similar properties—benzene, toluene, ethylbenzene, and xylene. These chemicals are naturally found in crude oil and petroleum products such as diesel and gasoline. They also have known health effects such as skin irritation, nervous system disruption, and liver and kidney damage with prolonged or concentrated exposure. The main concern with the use of diesel as a chemical additive is that BTEX chemicals could contaminate drinking water or air at sufficient levels to be a health risk.
Diesel fuel fracking vs. produced water
Produced water is certainly a source of these risks that must be managed. When fracking fluid travels down a wellbore and back again, it picks up underground chemicals and contaminants from the rock around it. Among these are oil and gas and organic compounds. As a result, untreated produced water is both flammable and contains BTEX chemicals. Due to the necessity of handling produced water over the last 60 years, the infrastructure and technology for dealing with flammable fluids is well established. However, because crude oil naturally contains BTEX, release of these chemicals is an inevitable effect of oil and gas production.
So how much is diesel fuel fracking contributing to this effect? Let’s take a look at some numbers. Rep. Henry Waxman’s 2011 report cites the use of 32 million gallons of diesel fluid over a four year period with 10 million gallons being pure diesel and 22 being “at least 30% diesel”3. That adds up to a maximum volume of 17.33 million gallons of diesel in 4 years—or 4.33 million gallons annually. In the US, around 135 billion gallons of water are used in fracking jobs each year.
What do these calculations tell us? Only around .003% of fracking fluid used annually is diesel.
This means that either diesel is only used very rarely, or that it is used at extremely low concentrations. Furthermore, on average, BTEX compounds make up less than .1% of diesel fuel.
While the toxicity of BTEX—particularly benzene—should always be a concern, modern diesel fuel fracking seems to be a negligible source in comparison to produced water and oil and gas production itself. Although regulatory battles are an efficient way to generate press, focus on produced water management may be a more efficient way to control BTEX contamination and effects.
1) Environmental Protection Agency, Office of Water. (2012).Permitting guidance for oil and gas hydraulic fracturing activities using diesel fuels – draft(UIC Program Guidance
2) Irwin, R. National Park Service, (1997). Environmental contaminants encyclopedia entry for btex and btex compounds
3) Lustgarten, A. (2011, February 2). Drilling industry says diesel use was legal. ProPublica,
4) MacRae, M. (2012, December). Fracking: A look back.American Society of Mechanical Engineers,
5) Soraghan, M. (2011, January 31). Fracking companies injected 32m gallons of diesel, house probe finds. New York Times