The university published a series of technical reports assessing the shale oil and natural gas potential in Michigan. The U.S. Energy Department said Michigan has the largest natural gas reserves of any state in the Great Lakes region.
The university said about 12,000 oil and natural gas wells have been drilled in the state since the 1940s using hydraulic fracturing without any contamination issues. Most of those were in shallow wells.
The reports, published Thursday, said the potential impact of hydraulic fracturing may be significant. Risks include erosion, chemical runoff, chemical spills and aquatic contamination. U of M researchers said surface spills were more likely than groundwater contamination.
The report said the high cost of drilling deeper shale wells, the absence of new oil discoveries in the state and the low price of natural gas means the near-term environmental threat is minimal.
The Energy Department said Michigan's natural gas production peaked in 1997 at 305 billion cubic feet. Production in 2011, the last full year for which data is available, was reported at 138 billion cubic feet.
The report said the gas extraction industry in the state is not enough to "make or break" its economy.