FRACKING, FLOCCING, AND FRACK-SAND MININGKelvin S. Rodolfo, Professor Emeritus

Department of Earth & Environmental Science University of Illinois at Chicago

TopicsWhat is “fracking”?Where is fracking done?What are frac sands?How did the Driftless area’s frac sands form?Environmental consequences of frac-sand miningFracking won’t happen here, so is it OK for us to provide sand for fracking elsewhere?

INTERMISSIONEnvironmental consequences of fracking Groundwater pollution Methane leakage and global warming Does fracking cause earthquakes?Consequence or staying hooked on natural gas and other fossil fuels

TRADITIONAL OIL AND GAS SITUATION

Source rock: fine-grained clay shale holding tiny dispersed oil droplets and/or bubbles of natural gas clinging to clay grains. Over millions of years, the gas and oil migrates up to traps.

Reservoir rock, porous sandstone

Impermeable cap rock

Natural gas

Most traditional oil/gas traps are now empty; fracking extracts oil and gas DIRECTLY from the source shales

Oil

Unlike traditional production from oil traps in very rare places under small areas, fracking operations are very widespread and involve many more drilling rigs.So many more people are affected.

Hydraulic fracturing; induced hydraulic fracturing; hydrofracturing; hydrofracking.Wells drilled 1-2 miles deep into fine-grained shales, then horizontally as much as 10,000 feet. Fracking fluid forced under high pressure (5,000 PSI) to fracture the shale. Fluid consists mostly of water and many chemicals, plus strong, round sand grains (“proppants”) to keep fractures propped open so gas or oil can escape and be collected.

5,000 psi

Sand grains prop fractures open for gas and oil to flow through to the well.

Each fracking well can use 2 to 3 million US gallons of water. Typical well uses 100,000 gallons of chemical additives of varying toxicity

1-2

mile

s

10,000 feet

1950

1960

1970

1980

1990

2000

2010

Oil and Gas Drilling in the U.S. Since 1950

4,000

3,000

2,000

1,000

0

Activ

e Dr

illing

Ri

gs

201

1

12

10

8

6

4

2

0

U.S. Oil Production, Millions of Barrels per Day

Frackingboom

Despite greatly increased drilling, oil production continues to decline . . .

Sources: Baker Hughes, Inc., Energy Information Administration, and Green Econometrics Researchhttp://greenecon.net/wp-content/uploads/w2008/2009/us_oil.jpg

. . . But U.S. Natural Gas Production is Booming!

http://peakwatch.typepad.com/.a/6a00d83452403c69e20133ecc4d8ef970b-800wi

Fracking produces much more gas than oil.

Oil/Gas shale prospect areas None in WI, IA, MN, but

frac sand is abundant!

Proposed

New Albin IACaledonia MN

Kickapoo Watershed geology Formations and their

ages in millions of years

CAMBRIAN: Mainly sandstones including the Jordan and Wonewoc formations 488+

ORDO

VICI

AN S

YSTE

M

Prairie du Chien Dolomite, 488-472

Platteville Limestone, 468-466

St. Peter Sandstone, 472-466

Best frack sands:

Mining these sands will pollute the Kickapoo