1. Hydraulic Fracturing in the Barnett Shale
Samantha Fuchs
GIS Water Resources
November 17th, 2015

2. Why are we concerned?
for methane, for texas

3. Hydraulic Fracturing: “Fracking”
Chemical Mix:
Surfactants
Biocides
Friction Reducers
Corrosion Inhibitors
Buffers
Proppants
Water risk:
Water consumption
Aquifer contamination
Incomplete treatment and byproducts
The process of fracking occurs to remove natural gas from shale within the subsurface. First, large volumes of water are taken from ground or surface water sources and mixed with different chemical additives. The EPA hydraulic fracturing study plan lists 25 pages of 40 chemicals per page – 1000 known chemical additives. They are surfactants (1-undecanol), corrosion inhibitions, buffers (acetic acid), polymers, friction reduction and other without specified functions, like cadmium. The fracking fluid mix is injected into the well at high pressure to crack geological formations and allow oil or gas to escape to the well for collection. However,
Image courtesy of EPA:

4. Shale Plays
These are Shale Plays of the United States. Shale is a sedimentary rock formed from particles settling in calm waters, and is typically high in organic content. This is not a list of all shale formations in the US – a Play is a specific term used by the oil and gas industry to highlight an area with an “economic quantity” of oil or gas present. Normally, heat and pressure cause these gases to rise into porous rock, creating conventional reservoirs. When the gas gets stuck, we have unconventional oil and gas, and unconventional methods like fracking are needed to retrieve them

5. Barnett Shale Features 5000 mi2 2.1-30 x1012 ft3 gas (estimate)
23 counties and Dallas-Fort Worth
The Barnett Shale is 5000 square miles, crossing 17 counties in Texas. It lies under several cities like Brownwood and Stephenville, but most significantly, the Dallas-Fort Worth Metroplex.Barnett shale is considered a tight reservoir, where most of the natural gas is inaccessible by traditional drilling and requires fracking. A lot of the drilling is complicated due to urban cover, so horizontal drilling is needed to expand under the city.

6. Major Aquifers of Texas
The Trinity aquifer is the major aquifer which occurs beneath the Barnett shale area. However, that doesn’t mean there’s no groundwater, it’s just that there are minor aquifers or smaller, individual areas that people can get their water from. There is both good and bad to this. A spill in a local area can be contained if a small aquifer is separated from other water resources by an aquitard.

7. Groundwater Wells
Zoomed in to the Barnett shale and Ft. Werth area. WE have a huge clustering of wells around Brownwood in the lower left and across the Dallas-Fort Worth. There’s way too much. So we’ll narrow it down to just a dozen counties in the Forth Worth Area.

8. Major Production Counties
5.75 million people, 4.4 million from Dallas and Tarrant counties
4165 groundwater wells
Narrow the focus to the Fort Worth and Dallas regions with Barnett Shale Fracking. Down to 4675 wells.

9. Gas Production County Totals per year 2001: 220 million Mcf
Map of percentage of gas retreival. Mcf is millions of cubic feet of natural gas.
County Totals per year
2001: 220 million Mcf
2006: 783 million Mcf
2011: 2185 million Mcf
2014: 1839 million Mcf

10. Future Work Population Risk
Analyze urban growth and water demand over time
Determine number of households in the major counties

11. Conclusions Thank you! Questions?
Fracking in the Barnett Shale may cause contamination to groundwater
Over 1.8 billion ft3 of natural gas was produced in Texas in 2014
5.75 million people live in these counties and get their drinking water mostly from the Trinity Aquifer
Thank you! Questions?