An Illinois State University geologist says the furor over possible hydraulic fracturing to liberate oil and natural gas deposits in central Illinois is misdirected. Anti-fracking groups have held several demonstrations against the practice in Bloomington-Normal and the county board has been asked to gather information about the practice to determine whether regulation on a local level is in order. Pro-business interests have also suggested easing regulations on test drilling. Skip Nelson says that's because to make methane, propane, and crude oil, New Albany Shale must be held at the right temperature. And Nelson says temperature is created by the pressure of the rock above the shale.
"Typically it takes a depth of about 4,500 feet to get it hot enough to reach the magic temperature. Too much hotter than that and it burns off everything. So there's a sweet zone from about 4,500 feet to about 6,000 feet."
Nelson says McLean County has only a tiny amount of the shale under the southwest corner of the county. In the 1980s the State Geological Survey did a thorough study of the shale in central Illinois and Nelson says they found McLean and Tazewell County pieces of the New Albany layer are at only 2000 feet, not enough to have deposits that are commercially exploitable.
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