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Shale Gas ExtractionApril 12, 2012

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The Utica and Marcellus Plays

Utica and Marcellus Shale are in the Appalachian Basin

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Relative & Approximate Depth

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Drilling

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Typical Gas Well X-Section

Multiple Layers ofSteel Casing and Cement Grout

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Vertical & Horizontal Drilling

Well typically drilled vertically to 500 above Marcellus Shale

Curve from vertical to horizontal approximately 1,200 linear feet

Continues horizontally for several thousand feet

Final casing string cemented in place at end of well bore

Approximately 15 to 30 days required to drill a horizontal Marcellus well

Example illustrates 7,000 depth to shale (Typical for Pennsylvania)

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Multiple Wells from a Single Pad

Line = 1,000 feet

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Hydraulic Fracturing

Intensive 24-hour operation, typically taking place over several days to stimulate the entire horizontal wellbore.

High-volume fracturing used for horizontal well development

Process begins by perforating casing, cement and shale with perforating gun

Charge from gun opens fissures in shale to release natural gas, sand necessary to expand and prop open fissures

Water & additives injected under high pressure to carry sand into fractures

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Hydraulic Fracturing

• Perforate the well casing & grout in sections

• Pressure & Volume highly dependent upon local geology

• Proppant (typically sand) keeps the fractures open

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Hydraulic Fracturing

> 1.2 Million wells hydraulically fractured in the US since 1949

“Typical” Fracture Fluid ~ 99.5% Water & Sand Remaining ~0.5%

▪ Surfactant▪ Gelling Agent▪ Friction Reducers▪ Acid▪ Biocide & Others

500,0000 to 4.0M gallons water/Marcellus well

20% – 30% returns as “Flow-back” water within a few days; “produced water” follows

Recycling or T&D

Pennsylvania AMD Re-use??

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Water Consumption

5,930

1,6801,550

268

6,000

5,000

4,000

3,000

2,000

1,000

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Shale Drilling

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