Methane and Water Contamination Associated with Shale Gas Development and Hydrofracking
-
Upload
cary-institute-of-ecosystem-studies -
Category
Technology
-
view
577 -
download
0
description
Transcript of Methane and Water Contamination Associated with Shale Gas Development and Hydrofracking
![Page 1: Methane and Water Contamination Associated with Shale Gas Development and Hydrofracking](https://reader035.fdocuments.us/reader035/viewer/2022062513/555b3f4bd8b42af36d8b479b/html5/thumbnails/1.jpg)
Methane and Water Contamination Associated with Shale Gas Development
and Hydrofracking
Avner Vengosh
Nicholas School of the Environment, Duke University
![Page 2: Methane and Water Contamination Associated with Shale Gas Development and Hydrofracking](https://reader035.fdocuments.us/reader035/viewer/2022062513/555b3f4bd8b42af36d8b479b/html5/thumbnails/2.jpg)
![Page 3: Methane and Water Contamination Associated with Shale Gas Development and Hydrofracking](https://reader035.fdocuments.us/reader035/viewer/2022062513/555b3f4bd8b42af36d8b479b/html5/thumbnails/3.jpg)
What are the environmental risks associated with shale gas drilling and
hydro-fracturing?
Water
• Does shale gas drilling and hydro-fracking cause contamination of drinking water wells?
• Does produced water disposal cause long-term ecological effects and health risks?
![Page 4: Methane and Water Contamination Associated with Shale Gas Development and Hydrofracking](https://reader035.fdocuments.us/reader035/viewer/2022062513/555b3f4bd8b42af36d8b479b/html5/thumbnails/4.jpg)
Figure from Scientific American Magazine, November 2011
Does shale gas drilling and hydro-fracking cause contamination of drinking water wells?
![Page 5: Methane and Water Contamination Associated with Shale Gas Development and Hydrofracking](https://reader035.fdocuments.us/reader035/viewer/2022062513/555b3f4bd8b42af36d8b479b/html5/thumbnails/5.jpg)
CH4
d13C – 13C/12C
d2H – 2H/H
Isotopic fingerprinting of methane source
![Page 6: Methane and Water Contamination Associated with Shale Gas Development and Hydrofracking](https://reader035.fdocuments.us/reader035/viewer/2022062513/555b3f4bd8b42af36d8b479b/html5/thumbnails/6.jpg)
Proceedings of National Academy of Sciences, May 17, 2011
![Page 7: Methane and Water Contamination Associated with Shale Gas Development and Hydrofracking](https://reader035.fdocuments.us/reader035/viewer/2022062513/555b3f4bd8b42af36d8b479b/html5/thumbnails/7.jpg)
Duke research in Pennsylvania and New York
![Page 8: Methane and Water Contamination Associated with Shale Gas Development and Hydrofracking](https://reader035.fdocuments.us/reader035/viewer/2022062513/555b3f4bd8b42af36d8b479b/html5/thumbnails/8.jpg)
Definition of active versus non-active wells: Private wells located <1km from a shale gas had typically higher methane
(based on about 60 wells)
![Page 9: Methane and Water Contamination Associated with Shale Gas Development and Hydrofracking](https://reader035.fdocuments.us/reader035/viewer/2022062513/555b3f4bd8b42af36d8b479b/html5/thumbnails/9.jpg)
Definition of active versus non-active wells: Private wells located <1 km from a shale gas had typically higher methane
(based on 91 wells)
Lockheaven FmCatskill Fm
![Page 10: Methane and Water Contamination Associated with Shale Gas Development and Hydrofracking](https://reader035.fdocuments.us/reader035/viewer/2022062513/555b3f4bd8b42af36d8b479b/html5/thumbnails/10.jpg)
Methane sources?
Active
Active
Non-active
Non-active
A distinction between active wells with a thermogenic isotopic fingerprint and non-active wells with a mixed composition
![Page 11: Methane and Water Contamination Associated with Shale Gas Development and Hydrofracking](https://reader035.fdocuments.us/reader035/viewer/2022062513/555b3f4bd8b42af36d8b479b/html5/thumbnails/11.jpg)
Thermogenic
Biogenic
Methane sources ?
![Page 12: Methane and Water Contamination Associated with Shale Gas Development and Hydrofracking](https://reader035.fdocuments.us/reader035/viewer/2022062513/555b3f4bd8b42af36d8b479b/html5/thumbnails/12.jpg)
Methane sources?
Thermogenic source
![Page 13: Methane and Water Contamination Associated with Shale Gas Development and Hydrofracking](https://reader035.fdocuments.us/reader035/viewer/2022062513/555b3f4bd8b42af36d8b479b/html5/thumbnails/13.jpg)
Possible mechanisms for leakage of stay gas to water resources
Figure from Scientific American Magazine, Nov 2011
Leakage of pressurized gas through uncompleted casing to shallow fracture systems
Migration from target formation via fracture system (could be enhanced by fracturing)
![Page 14: Methane and Water Contamination Associated with Shale Gas Development and Hydrofracking](https://reader035.fdocuments.us/reader035/viewer/2022062513/555b3f4bd8b42af36d8b479b/html5/thumbnails/14.jpg)
From Penoyer, (2011), Natural Resource Stewardship & Science
Possible mechanisms for leakage of stay gas to water resources
![Page 15: Methane and Water Contamination Associated with Shale Gas Development and Hydrofracking](https://reader035.fdocuments.us/reader035/viewer/2022062513/555b3f4bd8b42af36d8b479b/html5/thumbnails/15.jpg)
No apparent chemical contamination: no differences between active to non active wells
![Page 16: Methane and Water Contamination Associated with Shale Gas Development and Hydrofracking](https://reader035.fdocuments.us/reader035/viewer/2022062513/555b3f4bd8b42af36d8b479b/html5/thumbnails/16.jpg)
No apparent isotopic differences between active to non active wells
![Page 17: Methane and Water Contamination Associated with Shale Gas Development and Hydrofracking](https://reader035.fdocuments.us/reader035/viewer/2022062513/555b3f4bd8b42af36d8b479b/html5/thumbnails/17.jpg)
Results of the study indicate:
1. High methane concentration in active wells (<1 km from gas well) are associated with a distinguish chemical and isotopic composition identical to the Marcellus gas in production wells while wells located >1 km had lower methane and different composition;
2. Active wells were not contaminated by chemicals derived from contamination of produced waters.
![Page 18: Methane and Water Contamination Associated with Shale Gas Development and Hydrofracking](https://reader035.fdocuments.us/reader035/viewer/2022062513/555b3f4bd8b42af36d8b479b/html5/thumbnails/18.jpg)
Occurrence of saline groundwater enriched in barium in shallow aquifers
Warner, et al., Geochemical evidence for natural migration of Marcellus-like brine to shallow drinking water in Pennsylvania, submitted to PNAS)
![Page 19: Methane and Water Contamination Associated with Shale Gas Development and Hydrofracking](https://reader035.fdocuments.us/reader035/viewer/2022062513/555b3f4bd8b42af36d8b479b/html5/thumbnails/19.jpg)
1.00
10.00
100.00
1,000.00
10,000.00
Cl (mg/L)
Br (m
g/L)
Appalachian (Ordovician Silurian and Devonian) Brines
1 10100
100010000
100000
10000001
10
100
1000
10000
100000
Cl (mg/L)
Na
(mg/
L)Appalachian Brines(Ordovician Silurian and Devonian)
Mixing Line
Type D Water
Type C Water
Mixing Line
Upper Devonian Brines
Marcellus Brines
Mixing Line
1 10 100 1,000 10,000 100,000 1,000,00010
100
1,000
10,000
100,000
1,000,000
10,000,000
100,000,000
Cl (mg/L)
Ba (u
g/L)
Upper Devonian Brines
Marcellus Brines
Mixing Line
1 10 100 1,000 10,000 100,000 1,000,00010
100
1,000
10,000
100,000
1,000,000
10,000,000
Cl (mg/L)
Sr (u
g/L)
![Page 20: Methane and Water Contamination Associated with Shale Gas Development and Hydrofracking](https://reader035.fdocuments.us/reader035/viewer/2022062513/555b3f4bd8b42af36d8b479b/html5/thumbnails/20.jpg)
The strontium isotope fingerprint of the Appalachian brines
![Page 21: Methane and Water Contamination Associated with Shale Gas Development and Hydrofracking](https://reader035.fdocuments.us/reader035/viewer/2022062513/555b3f4bd8b42af36d8b479b/html5/thumbnails/21.jpg)
The strontium isotope fingerprint of the Marcellus brines
![Page 22: Methane and Water Contamination Associated with Shale Gas Development and Hydrofracking](https://reader035.fdocuments.us/reader035/viewer/2022062513/555b3f4bd8b42af36d8b479b/html5/thumbnails/22.jpg)
Deep water displacement
Hydrological connectivity between shallow aquifers and deep Marcellus brine
![Page 23: Methane and Water Contamination Associated with Shale Gas Development and Hydrofracking](https://reader035.fdocuments.us/reader035/viewer/2022062513/555b3f4bd8b42af36d8b479b/html5/thumbnails/23.jpg)
Does produced water disposal cause long-term ecological effects and health risks ?
![Page 24: Methane and Water Contamination Associated with Shale Gas Development and Hydrofracking](https://reader035.fdocuments.us/reader035/viewer/2022062513/555b3f4bd8b42af36d8b479b/html5/thumbnails/24.jpg)
Flowback from the Marcellus gas well: formation water
Days (after fracking)
Frack water
Frack water
![Page 25: Methane and Water Contamination Associated with Shale Gas Development and Hydrofracking](https://reader035.fdocuments.us/reader035/viewer/2022062513/555b3f4bd8b42af36d8b479b/html5/thumbnails/25.jpg)
• Inject underground through a disposal well (onsite or offsite),
• Discharge to a nearby surface water body,
• Haul to a municipal wastewater treatment plant,
• Haul to a commercial industrial wastewater treatment facility,
• Reuse for a future fracking job either with or without treatment.
Management of produced water
![Page 26: Methane and Water Contamination Associated with Shale Gas Development and Hydrofracking](https://reader035.fdocuments.us/reader035/viewer/2022062513/555b3f4bd8b42af36d8b479b/html5/thumbnails/26.jpg)
In 2009 about 140 million gallon were injected in Ohio;In 2011 a significant increase; nearly 50% is coming from PA where PA last May banned shipment of drilling waste to its sewage treatment plants. Ohio 181 injection wells were in full capacity.
Trigger for earthquakes ? (Oklahoma, 5.6R; Arkansas 4.7R;Youngstown, Ohio 2.7R; 4.0R (12/31/2011)
Deep well injection
![Page 27: Methane and Water Contamination Associated with Shale Gas Development and Hydrofracking](https://reader035.fdocuments.us/reader035/viewer/2022062513/555b3f4bd8b42af36d8b479b/html5/thumbnails/27.jpg)
![Page 28: Methane and Water Contamination Associated with Shale Gas Development and Hydrofracking](https://reader035.fdocuments.us/reader035/viewer/2022062513/555b3f4bd8b42af36d8b479b/html5/thumbnails/28.jpg)
Source: Cidney Christie, Duke
![Page 29: Methane and Water Contamination Associated with Shale Gas Development and Hydrofracking](https://reader035.fdocuments.us/reader035/viewer/2022062513/555b3f4bd8b42af36d8b479b/html5/thumbnails/29.jpg)
background
High salinity in the river water (up to 500m downstream)
The effects of brine disposal: (preliminary results)
background
![Page 30: Methane and Water Contamination Associated with Shale Gas Development and Hydrofracking](https://reader035.fdocuments.us/reader035/viewer/2022062513/555b3f4bd8b42af36d8b479b/html5/thumbnails/30.jpg)
background
The effects of brine disposal: (preliminary results)
High bromide in the river water (up to 500 m downstream)
background
• Long-term salinization of fresh water resources: high chloride and bromide in surface water enhance the formation of carcinogenic disinfection by-products (e.g., trihalomethane, bromodichloromethane) in potable water.
![Page 31: Methane and Water Contamination Associated with Shale Gas Development and Hydrofracking](https://reader035.fdocuments.us/reader035/viewer/2022062513/555b3f4bd8b42af36d8b479b/html5/thumbnails/31.jpg)
The effects of brine disposal: (preliminary results)
High barium in the river water (up to 500 m downstream)
background
![Page 32: Methane and Water Contamination Associated with Shale Gas Development and Hydrofracking](https://reader035.fdocuments.us/reader035/viewer/2022062513/555b3f4bd8b42af36d8b479b/html5/thumbnails/32.jpg)
The effects of brine disposal: (preliminary results)
background
Accumulation of radionuclides in river sediments (up to 300m downstream); implications for long-term radium bioaccumulation.
![Page 33: Methane and Water Contamination Associated with Shale Gas Development and Hydrofracking](https://reader035.fdocuments.us/reader035/viewer/2022062513/555b3f4bd8b42af36d8b479b/html5/thumbnails/33.jpg)
The take-home messages of this talk:
• Shale gas exploitation through hydro-fracturing may save America from foreign oil but seems to cause methane contamination in shallow drinking water wells in the Appalachian Basin.
• No evidence has shown, so far, for direct groundwater contamination from produced/flowback water; yet new data show possible hydraulic connectivity between the Marcellus and shallow aquifers in PA.
• Disposal of produced water from gas exploration directly into surface water poses a significant risks to the ecological systems and waterways in Pennsylvania.
• Sustainable and long-term shale gas developments will need to accommodate the environmental issues associated with shale gas drilling and hydro-fracturing.
![Page 34: Methane and Water Contamination Associated with Shale Gas Development and Hydrofracking](https://reader035.fdocuments.us/reader035/viewer/2022062513/555b3f4bd8b42af36d8b479b/html5/thumbnails/34.jpg)
Further reading:
Osborn, S., Vengosh, A. Warner, N. Jackson, R. (2011). Methane contamination of drinking water accompanying gas drilling and hydro-fracking. Proceedings of the National Academy of Sciences, 108, 8172-8176.
Acknowledgements:• Frank Stanback, North Carolina • National Science Foundation, Geobiology & Low-Temperature
Geochemistry Program • Nicholas School of Environment, Duke University
![Page 35: Methane and Water Contamination Associated with Shale Gas Development and Hydrofracking](https://reader035.fdocuments.us/reader035/viewer/2022062513/555b3f4bd8b42af36d8b479b/html5/thumbnails/35.jpg)
Further information:
http://sites.nicholas.duke.edu/avnervengosh/
NSF Workshop at Duke (January 9, 2011): Environmental and Social Implications of Hydraulic Fracturing and Gas Drilling in the United States: An Integrative Workshop for the Evaluation of the State of Science and Policy
http://www.nicholas.duke.edu/hydrofrackingworkshop2012/workshop