from biogenic coalbed gas in Ohio drinking water wells near shale gas extraction
Univ_Cinn_Groundwater_Study_CC_Presentation_2016
Univ_Cinn_Groundwater_Study_CC_Presentation_2016
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Elevated methane levels<br />
<strong>from</strong> <strong>biogenic</strong> <strong>coalbed</strong> <strong>gas</strong> <strong>in</strong> <strong>Ohio</strong> dr<strong>in</strong>k<strong>in</strong>g <strong>water</strong><br />
<strong>wells</strong> <strong>near</strong> <strong>shale</strong> <strong>gas</strong> <strong>extraction</strong><br />
Claire Botner, Amy Townsend-Small, and David Nash<br />
Department of Geology, University of C<strong>in</strong>c<strong>in</strong>nati<br />
Paul Feezel<br />
Carroll Concerned Citizens
Natural Gas<br />
• Recent glut <strong>in</strong> natural<br />
<strong>gas</strong> production <strong>in</strong> U.S.<br />
• Is natural <strong>gas</strong> a bridge<br />
between traditional<br />
fossil fuel sources and<br />
renewable energy?<br />
• Primary component is<br />
methane (CH 4 ) – a<br />
greenhouse <strong>gas</strong> 34x<br />
more powerful than CO 2<br />
warriorpublications.wordpress.com
Coal/Oil-To-Gas Transition<br />
United States Energy Information Adm<strong>in</strong>istration
Conventional vs. Unconventional Drill<strong>in</strong>g
How Frack<strong>in</strong>g<br />
Works<br />
1. Vertical drill<strong>in</strong>g ~3 km +<br />
horizontal drill<strong>in</strong>g up to 1<br />
km<br />
1. Detonation of explosives<br />
<strong>in</strong> well after drill<strong>in</strong>g<br />
1. A mix of <strong>water</strong>, sand,<br />
and chemicals are<br />
pumped at very high<br />
pressure <strong>in</strong>to the well to<br />
release <strong>gas</strong> <strong>from</strong> fissures<br />
Photo credit: Casey White
Potential Pathways of NG Contam<strong>in</strong>ation<br />
Darrah et al., 2014
Methane: Where can you f<strong>in</strong>d it?<br />
• Natural <strong>gas</strong>: ~95% CH 4<br />
• Two ma<strong>in</strong> forms of CH 4<br />
– Thermogenic (created <strong>from</strong> <strong>in</strong>tense heat and<br />
pressure of organic matter deep <strong>in</strong> the Earth;<br />
i.e. natural <strong>gas</strong>, oil)<br />
– Biological (created <strong>from</strong> microbial<br />
methanogensis; i.e. landfills, rum<strong>in</strong>ant<br />
animals, wetlands, rice paddy agriculture)<br />
• Acetate fermentation<br />
• Carbonate Reduction
Stable Isotope Primer<br />
• Isotope: Atom of a specific element that differs <strong>in</strong> the<br />
number of neutrons <strong>in</strong> the nucleus<br />
• Isotopes with an extra neutron have the same chemistry but<br />
are slightly heavier than other atoms of the same element<br />
• Stable isotopes of methane:<br />
• Hydrogen<br />
– Hydrogen-1 (99.98% of all H atoms)<br />
– Hydrogen-2 (deuterium or D) (0.01%)<br />
• Carbon<br />
– Carbon-12 (98.9%)<br />
– Carbon-13 (1.1%)<br />
Carbon-13<br />
Carbon-12
D (‰)<br />
C and H stable isotopes of CH 4<br />
! D (‰ )<br />
0<br />
- 50<br />
- 100<br />
- 150<br />
- 200<br />
- 250<br />
- 300<br />
- 350<br />
cows<br />
oil fi eld<br />
power plant<br />
tra! c<br />
manure biofuel<br />
landfi ll emissions<br />
landfi ll biofuel<br />
- 400<br />
- 70 - 60 - 50 - 40 - 30<br />
! 13 C (‰ )<br />
Townsend-Small et al., 2012
What is the problem?<br />
• Is hydraulic fractur<strong>in</strong>g contribut<strong>in</strong>g to methane found <strong>in</strong><br />
ground<strong>water</strong> resources of the Utica Shale?<br />
• Previous studies (Osborn et al., 2011; Jackson et al.,<br />
2013) found that natural <strong>gas</strong> was present <strong>in</strong><br />
ground<strong>water</strong> resources after the onset of frack<strong>in</strong>g <strong>in</strong> the<br />
Marcellus Shale<br />
– Utilization of stable carbon isotope analysis<br />
• Our study aims to measure methane and its sources <strong>in</strong><br />
ground<strong>water</strong> before, dur<strong>in</strong>g, and after the onset of<br />
frack<strong>in</strong>g
Osborn et al., 2011<br />
z<br />
Jackson et al., 2013
Frack<strong>in</strong>g and <strong>water</strong> resources<br />
• Each well takes several million gallons of <strong>water</strong> to<br />
“frack”<br />
– Additives<br />
• Sand<br />
• Acids<br />
• Biocides<br />
• Salts<br />
• Antifreeze<br />
• Corrosion <strong>in</strong>hibitors<br />
– Some specific chemicals are proprietary and drillers<br />
need not disclose their formulas, although many do<br />
voluntarily
Frack<strong>in</strong>g and <strong>water</strong> resources<br />
• After fractur<strong>in</strong>g, <strong>water</strong> is returned to the<br />
surface with additional solutes <strong>from</strong><br />
<strong>in</strong>teractions with the <strong>shale</strong>s<br />
– Salts<br />
– Methane<br />
– Hydrocarbons (benzene, etc.)<br />
– Radioactive materials<br />
• Disposal or reuse
youtube.com<br />
Highly viewed YouTube<br />
video show<strong>in</strong>g dr<strong>in</strong>k<strong>in</strong>g<br />
<strong>water</strong> with high levels of<br />
methane
Study<br />
Area<br />
Permitted<br />
Drill<strong>in</strong>g<br />
Drilled<br />
Produc<strong>in</strong>g
Methods<br />
• Teamed with Carroll<br />
Concerned Citizens to<br />
recruit participants<br />
• Private ground<strong>water</strong> well<br />
sampl<strong>in</strong>g <strong>in</strong> Carroll<br />
County, <strong>Ohio</strong> and<br />
surround<strong>in</strong>g area<br />
– 23 <strong>wells</strong> sampled <strong>from</strong> 2012<br />
to Feb. 2015 three to four<br />
times a year<br />
• 191 samples total<br />
– Larger campaign <strong>in</strong> May<br />
2014
What was measured?<br />
• CH 4 Concentration<br />
• Stable isotope<br />
composition of<br />
methane<br />
– δ 13 C and δD<br />
• pH and Conductivity<br />
– Indicators of frack<strong>in</strong>g<br />
fluid contam<strong>in</strong>ation<br />
• Δ 14 C analysis
University of<br />
C<strong>in</strong>c<strong>in</strong>nati’s Stable<br />
Isotope Facility<br />
Carbon and hydrogen<br />
isotope analysis performed<br />
with an isotope ratio mass<br />
spectrometer
pH<br />
Results<br />
pH vs. Conductivity of Ground<strong>water</strong> Wells <strong>in</strong> Eastern <strong>Ohio</strong><br />
10<br />
9<br />
8<br />
Distance to <strong>near</strong>est active<br />
<strong>gas</strong> well<br />
With<strong>in</strong> 1 km<br />
With<strong>in</strong> 1-2 km<br />
7<br />
With<strong>in</strong> 2-5 km<br />
With<strong>in</strong> 5-10 km<br />
> 10 km<br />
6<br />
5<br />
4<br />
100 1000 10000<br />
Conductivity (μS)
Numer of Wells<br />
60<br />
Dissolved CH 4 Concentration <strong>in</strong> Participant Wells, May 2014<br />
50<br />
48<br />
• Methane data histogram<br />
Total Number of Wells<br />
Sampled: 96<br />
40<br />
30<br />
20<br />
15<br />
10<br />
8<br />
7<br />
10<br />
3<br />
4<br />
0<br />
1<br />
Below 1 μg/L 1 - 10 μg/L 10 - 100 μg/L .1 - 1 mg/L 1 - 5 mg/L 5 - 10 mg/L Above 10 mg/L<br />
Concentration of Dissolved CH 4
Dissolved CH 4 Concentration (mg/L)<br />
Time Series of CH 4 Levels <strong>in</strong> Ground<strong>water</strong> Well “C”<br />
0.06<br />
Ground<strong>water</strong> Well C<br />
0.05<br />
0.04<br />
February 2014:<br />
Natural <strong>gas</strong><br />
well drilled<br />
with<strong>in</strong> 1 km of<br />
<strong>water</strong> well<br />
0.03<br />
0.02<br />
0.01<br />
0<br />
Dec-12 Apr-13 Aug-13 Dec-13 Apr-14 Aug-14 Dec-14<br />
Date
Dissolved Methane Concentration (mg/L CH 4 )<br />
Dissolved CH 4 Concentration vs. δ 13 C CH 4 of Ground<strong>water</strong> Wells<br />
Biogenic<br />
Thermogenic<br />
30.0<br />
Distance to <strong>near</strong>est<br />
active <strong>gas</strong> well<br />
25.0<br />
20.0<br />
Isotope figures<br />
Jackson et<br />
al. (2013)<br />
Ground<strong>water</strong><br />
Samples<br />
0 - 1 km 1 - 2 km<br />
2 - 5 km 5 - 10 km<br />
> 10 km<br />
15.0<br />
10.0<br />
5.0<br />
0.0<br />
-95.0 -90.0 -85.0 -80.0 -75.0 -70.0 -65.0 -60.0 -55.0 -50.0 -45.0 -40.0 -35.0 -30.0<br />
δ 13 C CH 4 (‰ VPDB)
δ 13 C-CH 4 (‰ VDPD)<br />
δ 13 C-CH 4 vs. δ 2 H-CH 4 of Ground<strong>water</strong> Samples and Previously Reported<br />
Appalachian Natural Gases<br />
-90.0<br />
Dissolved CH 4<br />
-80.0<br />
< 1 mg/L<br />
1 - 5 mg/L<br />
5 - 10 mg/L<br />
-70.0<br />
> 10 mg/L<br />
NG Appalachia (Jenden et al. 1993)<br />
-60.0<br />
CBM Appalachia (Laughrey and<br />
Baldassare 1998)<br />
-50.0<br />
-40.0<br />
-30.0<br />
-350 -300 -250 -200 -150 -100 -50 0<br />
δ 2 H-CH 4 (‰ VSMOW)
odnr.gov
Radiocarbon Primer<br />
• Sun 14 N to 14 C 14 CO 2 Plants Animals<br />
• “Modern” carbon: conta<strong>in</strong>s measureable 14 C<br />
• Positive Δ 14 C values<br />
• Methane orig<strong>in</strong>at<strong>in</strong>g <strong>from</strong> bacteria<br />
• “Dead” carbon: undetectable levels of 14 C<br />
• Reach<strong>in</strong>g close to -1000 ‰<br />
• Coalbed CH 4<br />
Carbo<br />
n
D 14 C - CH 4 (‰)<br />
Δ 14 C vs. δ 13 C of various CH 4 sources<br />
200<br />
0<br />
-200<br />
-400<br />
Natural <strong>gas</strong><br />
Anaerobic organic matter<br />
respiration<br />
Carbonate reduction <strong>in</strong> coal<br />
beds<br />
Ground<strong>water</strong> Samples<br />
-600<br />
-800<br />
-1000<br />
-1200<br />
-80 -70 -60 -50 -40 -30 -20<br />
13 C - CH 4 (‰)<br />
Figure credit: Amy<br />
Townsend-Small
Conclusions<br />
• Some <strong>water</strong> <strong>wells</strong> conta<strong>in</strong> very high levels of<br />
CH 4<br />
– Explosive range ~10 – 24 mg/L CH 4<br />
• δ 13 C values <strong>in</strong>dicate that CH 4 found <strong>in</strong><br />
ground<strong>water</strong> has biological orig<strong>in</strong>s<br />
• Ground<strong>water</strong> contam<strong>in</strong>ation <strong>from</strong> frack<strong>in</strong>g has<br />
happened, but it isn’t the norm<br />
• Normal pH and conductivity values show that<br />
frack<strong>in</strong>g fluid is likely not present <strong>in</strong> sampled<br />
ground<strong>water</strong> resources
Conclusions & Future Work<br />
• Δ 14 C analysis of four select <strong>wells</strong> <strong>in</strong>dicates<br />
high levels of CH 4 can be attributed to<br />
<strong>biogenic</strong> <strong>coalbed</strong> <strong>gas</strong>es <strong>in</strong> at least three of<br />
the <strong>wells</strong><br />
• Further characterization of <strong>coalbed</strong> <strong>gas</strong> <strong>in</strong><br />
eastern <strong>Ohio</strong> ground<strong>water</strong><br />
• Long-term monitor<strong>in</strong>g necessary
Acknowledgements<br />
• Dr. Amy Townsend-Small<br />
• Dr. David Nash<br />
• Paul Feezel, Carroll Concerned Citizens<br />
• Krist<strong>in</strong>e Jimenez<br />
• Deer Creek Foundation<br />
• Alice Weston Foundation
Questions?
Mart<strong>in</strong>i et al. 1998