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1 Opportunities and Challenges of Shale Gas Development Mark D. Zoback Professor of Geophysics Director
1
Opportunities and Challenges
of Shale Gas Development
Mark D. Zoback
Professor of Geophysics
Director
Global Energy and
Environment Challenge
How Do We Provide Twice As Much Accessible, Affordable, and
Secure Energy While Protecting the Planet?
Society
Economy
Environment
National Security
The World in 2050
~ 9 Billion People
Growing Demand for Energy Services
3• Increasing at 2.1% per year
Energy
Consumption
(Quads)
0
100
200
300
400
500
600
2004 2006 2008 2010 2012
Source: Enerdata, 2014.
2014 Symposium | Moving the Clean Energy Agenda Forward
Coal Use Continues to Grow
4
0
20
40
60
80
100
120
140
160
180
2004 2006 2008 2010 2012
Coal Consumption
(Quads)
Source: EIA International Energy Statistics 2014.
Growth ~ 3.7%/year
Shanghai, January
Air Pollution Linked to 1.2 Million Premature
Deaths in China Each Year
April 2013
In the U.S , the health effects from coal-fired
power plants cost the nation about
$62 billion per year. (NRC, 2010)
Global Shale Gas ~ 200 Years of Supply
source | EIA based on Advanced Resources International Inc. data, BPgraphic | Catherine Trevethan, Reuters
6
Horizontal Drilling and Multi-Stage
Slick-Water Hydraulic Fracturing
Induces Microearthquakes (M ~ -1 to M~ -3)
To Create a Permeable Fracture Network
SHmax
Multi-Stage Hydraulic Fracturing
Dan Moos et al.
SPE 145849
U.S. Natural Gas Production
(billions of cubic feet per day)
Shale Gas
Non-Shale Gas
20
30
40
50
60
70
2000
2003
2006
2009
2012
Unconventional
Conventional
2005
Source: U.S. Department of Energy, Energy Information Administration (EIA)
Air Pollution and Energy Source*
CO2 117,000 164,000 208,000
CO 40 33 208
NOx 92 448 457
SO2 0.6 1,122 2,591
Particulates 7.0 84 2,744
Formaldehyde 0.75 0.22 0.221
Mercury 0 0.007 0.016
EIA, 1998
CH4 Oil Coal
*Pounds/Billion BTUSource: U.S. Energy Information Administration, Monthly Energy Review.CO2 emissions from coal were down 18% to 387 million metric tons in the January-March 2012 period.
~20% Reduction in CO2
Emissions From Coal Since 2006
Horizontal Drilling and Multi-Stage Frac’ing Are
Large-Scale Industrial Processes
Opportunities and Challenges of
Shale Gas Production
The Bridge (U.S. National Academy of Engineering), 2014
Opportunities and Challenges of
Shale Gas Production
The Bridge (U.S. National Academy of Engineering), 2014
Does Vertical Hydrofrac
Growth Affect
Water Supplies?
NO!
(No Evidence of HF
Causing Contamination After ~2M HF’s)
Evidence for Stray Gases in a Minority of Houses <1km away
Jackson et al.2013 PNAS
Courtesy George King, Apache Corp.
C
To Prevent Leakage, Casing and
Cementing are CriticalCoal Seam
Saline Aquifer
Minor Gas Producing Shales
Surface Casing at 500 ft.
Aquifers
Top of Cement
Secondary Casing
Production Casing
Additional Casing at 2000 ft.
Provides Secondary Barrier
to Leakage
API Recommended Practice
Best Practice
Well Construction
Well Construction
Well Construction
Opportunities and Challenges of
Shale Gas Production
The Bridge (U.S. National Academy of Engineering), 2014
EPA Natural Gas Inventory
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Total leakage fraction = ~1.5% (2013 inventory)
The Impact of “Super-Emitters”
• Bottom-up studies suggest that unintentional
leakage rates vary greatly between devices
– Most devices do not leak
– A small fraction of components or devices
leak excess gas (1 - 4%)
– A very small fraction (<1%) leak a large
amount. These super-emitters often contribute
a large fraction of the total leakage
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Example Hydrocarbon Leak
19Source: Englander, Wang, Brandt, Jackson (2015)
Boston (~3,400 leaks; 800 road miles)
#1 predictor – miles cast iron pipes; P<0.001
Red = roads driven; Yellow = leaksPhillips et al. 2013 Env Pollution
Opportunities and Challenges of
Shale Gas Production
The Bridge (U.S. National Academy of Engineering), 2014
Shale Development Operations In
Pennsylvania
Some of its changes:
1) Restrict drilling within 1000 ft of a public water supply.
2) Double the distance from 250 feet to 500 feet to separate
a gas well from a private water well,
3) Extend a well operator's presumptive liability for pollution
or water loss from 1,000 feet to 2,500 feet.
February, 2012
Opportunities and Challenges of
Shale Gas Production
The Bridge (U.S. National Academy of Engineering), 2014
Earthquakes in the Mid-Continent
Ellsworth (2013)
Earthquakes in the Mid-Continent
Ellsworth (2013)
25,000’
BASEMENT
SHALE
TRIGGERED SEISMICITY
WATER DISPOSAL WELLWATER DISPOSAL WELL HORIZONTAL SHALE WELL
SAND
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Earth
Stress
EARTH April, 2012
Seismological Research Letters, 2015
I. Be Proactive
M 2.3 Earthquake During HF in
Bowland Basin
II. Avoid Injection Near Potentially Active Faults
III. Consider Water Recycling As in Pennsylvania
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Thank you
