Presentation on theme: "FRACKING, FLOCCING, AND FRACK-SAND MINING Kelvin S. Rodolfo, Professor Emeritus Department of Earth & Environmental Science University of Illinois at Chicago."— Presentation transcript:
FRACKING, FLOCCING, AND FRACK-SAND MINING Kelvin S. Rodolfo, Professor Emeritus Department of Earth & Environmental Science University of Illinois at Chicago
Topics What is “fracking”? Where is fracking done? What are frac sands? How did the Driftless area’s frac sands form? Environmental consequences of frac-sand mining Fracking won’t happen here, so is it OK for us to provide sand for fracking elsewhere? INTERMISSION Environmental 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 miles 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 Active Drilling Rigs 2011 12 10 8 6 4 2 0 U.S. Oil Production, Millions of Barrels per Day Fracking boom Despite greatly increased drilling, oil production continues to decline... Sources: Baker Hughes, Inc., Energy Information Administration, and Green Econometrics Research http://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!
Kickapoo Watershed geology Formations and their ages in millions of years CAMBRIAN: Mainly sandstones including the Jordan and Wonewoc formations 488+ ORDOVICIAN SYSTEM 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