Earlier discussions on the fracking process produced four posts on this blog. Recapping some earlier information, In Fracking’s Early History, the first fracking experiment was conducted in 1947 and based on the studies of Floyd Farris at Stanolind Oil and Gas Corporation in the Hugoton Gas Field of Grant County, Kansas. However, fracking didn’t become more widely used by energy companies until the 1990s when new equipment and technology made the process more efficient and cost effective.
One thing that may have been furthest from anyone’s thoughts in the Hugoton Gas Field almost 70 years ago was the environmental impacts that may have resulted from this test experiment. As the fracking process and technology associated with it have improved over the last 50 years, so have concerns about the volume of chemicals, water, and waste that are left behind and their impacts on air, water, and climate change.
As a reminder, the fracking process involves injecting water with a mix of chemical additives into rock formations deep underground to promote the release of natural gas or oil from shale formations. One of the negative complaints about fracking is the large volumes of water used to complete the process. Using data collected from the Bakken, Barnett, Denver, Fayetteville, Haynesville, Marcellus, and Woodland shale plays, an average of 14,500,000 liters ( 3,800,000 gallons) of frack water being used per well with a range of 8.7 to 21.5 million liters (2.3 to 5.67 million gallons) is reported. [Ref 1]
However, the report also notes that up to 80,000 cubic meters (20 million gallons) of water, proppants such as sand, and chemicals have been pumped underground at pressures sufficient to crack impermeable rock formations (10,000–20,000 psi). The composition of fracking fluid also varies from state to state and driller to driller.
It is also noted that during the early years of fracking, a typical process included the use of 750 gallons of fluid (water, gelled crude oil, or gelled kerosene), 400 pounds of sand, and the average power needed to pump the fracking materials was about 75 hydraulic horsepower (hhp). Fast forward to today and the larger volume of water, chemicals, and high back pressure work together to help free the trapped oil or gas in the shale formations.
The United States Geological Survey (USGS) also provides the following caveat for water usage in fracking wells: There may not be a “typical” fractured well because the water used depends on the rock formation, the operator, whether the well is vertical or horizontal, and the number of portions (or stages) of the well that are fractured. In addition, some water is recycled from fluids produced by the well so the net consumptive use may be smaller at sites that do not recycle.
The table below (Source: USGS [Ref 2]) shows the statistics of data on water-based fluid volumes used to hydraulically fracture oil and gas wells drilled from 1947 through 2010:
One conclusion that can be drawn from these limited data points is that the volume of water used in the fracking process varies, and perhaps the higher numbers that have been reported in the media and elsewhere (hundreds of millions of gallons to 1 billion gallons) represent the maximum vs average volumes for most fracking operations.
A comparison of fracking’s water usage to other energy production processes like electric power plants or traditional oil and gas wells may be worth taking a look at in the future, along with agricultural and other industrial operations.
In the next post on this topic, the composition of fracking fluids will be discussed.
- The Environmental Costs and Benefits of Fracking, Jackson, Robert B. et.al., published in the Annual Review of Environmental Resources, http://news.stanford.edu/news/2014/september/fracking-costs-benefits-091214.html, August 2014
- Trends in Hydraulic Fracturing Distributions and Treatment Fluids, Additives, Proppants, and Water Volumes Applied to Wells Drilled in the United States from 1947 through 2010— Data Analysis and Comparison to the Literature, Scientific Investigations Report 2014–5131 U.S. Department of the Interior – U.S. Geological Survey, By Tanya J. Gallegos and Brian A. Varela, Table 2