The Water Footprint of Fracking: Probably Only an Issue in Arid Areas with Scarce Groundwater AND Immature Oil & Gas Water Management Systems and Practices: Also the Reasons for Increased Water Usage

The Water Footprint of Fracking: Probably Only an Issue in Arid Areas with Scarce Groundwater AND Immature Oil & Gas Water Management Systems and Practices: Also the Reasons for Increased Water Usage

A recent paper by researchers at Duke University emphasizes the increasing water usage and wastewater generation of fracking. The study designer and co-author, Abner Vengosh, was lead author in some earlier papers that were somewhat misleading and partially debunked about the extent and sources of methane migration early in horizontal well fracking history. Yes, water usage has increased quite a bit due to higher pumping rates (early on) and longer well laterals. However, there is no shortage of water in areas like the U.S. Northeast. Areas in the U.S. Southwest can be affected by water usage and water well drawdown. According to the paper (referenced below) the water usage per well in the Marcellus region only increased 20% from 2011 to 2016. Part of the reason for this small increase is that the region was at the time working toward the highest percentage of wastewater treating, recycling, and reuse. The Permian Basin region of West Texas had the highest increase from 2011 to 2016 (770%) in part due to longer wells being drilled requiring more water. The paper shows that both the West Texas Permian region and the South Texas Eagle Ford region show the most potential for both increased water usage and subsequently increased flowback and produced water.

Water management – both of freshwater draw and flowback and produced water is a big issue in oil and gas these days and there are many solutions coming forward. Texas has many saltwater injection wells capable of handling wastewater. I predict that as water reuse becomes more common there the increase will become less through time. However, anti-fossil fuel advocates like Climate Progress founder Joe Romm put their own spin on the Duke researcher’ paper. Note their headline involving the same paper: “Fracking is destroying U.S. water supply, warns shocking new study: Toxic wastewater from fracking jumps 14-fold from 2011 to 2016 — and it may get 50 times bigger by 2030.” He calls it a game-changing study but most reasonable people would see it as a manageable problem. Even Popular Science headlined their coverage of the paper to seem as if the increase of water per well was a big issue. Actually, there are two issues. 1) A well twice as long as another will use twice as much water, and 2) a well with more closely-spaced frac stages will use more water than one with further-spaced frac stages. Both of these things have occurred and have drastically increased the amounts of gas and oil extracted per well. The paper does not seem to mention point number 2, which mainly accounts for the strong increase in production per rig from late 2014 through early 2016. In 2011 the Permian region was just getting started and shorter laterals were drilled to test the viability and define the extents of the play. I speculate that this is a strong factor in the increase in the Permian as longer laterals with close-spaced frac stages were adapted quickly in the second half of the study period. This has also occurred in the Marcellus region and makes one wonder why they didn’t see a bigger increase of water usage there. As previously mention, perhaps the increase in water reuse in the Marcellus region (thought to be the highest of the shale plays) is a strong contributing factor as the amount of water recycled increased in that time period. Quite a bit of acreage in the more populated Marcellus area is constrained by lease boundaries so that even though wells got longer, on average the Permian area was able to increase well length, and thus water usage, faster. It is unclear sometimes in reading the paper and the reporting about it – whether one is talking about water use per well, which would be a function of longer laterals and more closely-spaced frac stages which means more frac stages per well and so more water usage per well vs. water use per foot, which is more a function of just more closely-spaced frac stages, regardless of length of well.

The Duke paper suggests that water usage per well and per foot drilled will continue to increase in the future. Well, water usage per well will likely increase for a few years (since the data they use is 2 years behind) as well lengths continue to increase but each play will have a maximum safe well length and it is thought that the longest current laterals are close to that max safe well length. I would guess 5-10 years  from 2016 we will begin seeing max avg. well lengths level out. Water use per frac stage is probably currently at optimum levels. Frac stage spacing is also close to optimum levels as getting closer will yield diminishing returns per stage. Therefore, it is likely that after max safe well lengths are worked out the water usage per well and water usage per foot will cease to rise.  

Wastewater management and recycling systems have become the norm in the northeast and other places. The industry has advanced in the last decade in handling the increased water volumes. There is room for improvement in efficiency of recycling. The paper also points out that coal mining is more water intensive than gas and oil drilling per energy unit and that coal burning is more water intensive than gas burning per unit of energy so any overall water usage increase is partially offset by producing and burning more gas relative to coal. The Duke authors also point out that “the overall water withdrawal for hydraulic fracturing is negligible compared to other industrial water uses on a national level…” The paper also rightly points out that water scarcity is nearly always a local issue so the arid west, particularly the Permian and Eagle Ford areas, are most vulnerable. I have heard that the state of New Mexico, part of the Permian Basin, is currently limiting water use for fracking in some areas. 

Many studies of fracking impacts are ongoing at the federal level. The National Science Foundation has an ongoing study integrating food, water, and energy systems in the northern Great Plains where the population is low but energy and especially agricultural production are high. Both are water intensive. Other federal agencies such as the USGS, the EPA, and the DOE are investigating things like the composition of flowback and produced water (USGS), potential impacts from spills and gas migration on drinking water sources (EPA), and possible exposure routes of fluids and chemicals from wellbores and tanks (DOE). There are also well sites being used as 'testing laboratories' by the DOE where all systems are monitored including water use,  possibility of contamination, possible leaching of heavy metals and radioactivity of drill cuttings, etc.

References:

The Intensification of the Water Footprint of Hydraulic Fracturing – by Andrew J. Kondash, Nancy E. Lauer, and Avner Vengosh, in Science Advances Vol. 4, No. 8, Aug. 15, 2018

Fracking is Destroying U.S. Water Supply, Warns Shocking New Study – by Joe Romm, in Think Progress, Aug. 17, 2018

Alarmist Headlines Obscure Context of Duke Study on Water Use and Fracking – by Dan Alfaro, in Energy In Depth, Aug. 17, 2018

New Fracking Wells are Using Many Times More Water Than Their Predecessors – by Kat Eschner, in Popular Science, Aug. 15, 2018

When oil and water mix: Understanding the environmental impacts of shale development – by Daniel J. Soeder and Douglas B. Kent, in Geological Society of America, GSA Today, Vol 28, Issue 9, September 2018