Why Is Shale Gas Development
“Unconventional”
• Because it requires 3 technologies only recently
combined to make gas production from shales
technically and economically feasible.
• Directional drilling: needed to access a thin layer of
shale with long laterals.
• High frac fluid volumes: needed to stimulate gas
release from many existing fractures.
• Slickwater: needed to control the amount of power
needed to pump large volumes of frac fluids, at high
pressures, quickly, over long distances, through small
diameter casing.
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High Volume, Slickwater Fracing from
Long Laterals: The Concept
Not to scale
~ 5000 feet
Cap rock
Cap rock
The Lateral
~ 100 feet
Pay zone
2
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Early Joints at Taughannock Falls
Gas Producing Shales are Heavily Fractured Naturally
J1
J2
Geneseo-Burket (Devonian black shale)
Taughannock Falls State Park, Trumansburg, N.Y.
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Photo Courtesy T. Engelder3
Why Is Slickwater, High-Volume Fracing
from Long Laterals a Higher
Risk to Human Health?
• Requires much higher well density, many wells per
square mile.
• Requires much more industrial development over large
areas, heavy equipment operating 24/7/365.
• Requires much higher volumes of fracing fluid, millions of
gallons per well.
• Produces much higher volumes of waste fluids and solids
containing hazardous materials: frac fluid chemicals,
heavy metals, NORMS.
• Produces much higher volumes of fugitive emissions of
methane.
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Example: Dallas/Fort Worth Airport Property,
Barnett Shale Play
• 53 pads on 18,076 acres
•Each red line is a well
• Almost complete
coverage
• Patchwork, mostly ideal
units
• One developer
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Ideal Arrangement of Spacing Units
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Why Is Slickwater, High-Volume Fracing
from Long Laterals a Higher
Risk to Human Health?
• As number of wells and volumes of waste increase,
probability of accidental releases of hazardous
materials into air and groundwater increases.
• Cumulative effects on air and water from purposeful
emissions into the atmosphere and releases into
groundwater are unknown.
• Increased production and burning of natural gas and
its liquid companions (e.g. ethane, propane, butane)
increases emission of GHG’s.
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