As oil production has soared, the U.S. frac sand mining industry has boomed over the past 18 months. Yet one frac sand operation in Shakopee was recently idled and another one in western Wisconsin was partly shut down.
The cutbacks may be part of a fundamental shift in U.S. frac sand production away from the Midwest, home to the highest quality Northern White, to lesser-grade sands. As a result, Northern White's market share is expected to be 43 percent in 2019, down from 75 percent in 2014, according to global consulting firm Rystad Energy.
"That is the reality of things," said Thomas Jacob, a senior analyst at Rystad.
Oil producers in Texas and eastern New Mexico — by far the nation's largest shale oil-producing region — have increasingly switched from Northern White to sand produced at a growing number of regional mines.
"Some of this is definitely a structural change," said Kent Syverson, a geology professor at the University of Wisconsin-Eau Claire and a sand industry consultant.
Regional sands mined in places like Texas are inferior to Northern White, but they are far cheaper since transportation costs are minimal. And so far, oil production hasn't suffered from using lesser-quality sand, analysts say.
Regional sand has turned out to be "good enough" for the oil industry, Syverson said.
The shifting sand market doesn't portend the end of frac sand mining in Wisconsin and Minnesota. Northern White is still the staple sand used in North Dakota's fields, the second-largest producer of oil in the U.S. Even in the Southwest, there will still be some demand for Northern White, as some oil wells — due to local geology — will require a superior quality sand. But the frac industry in the Midwest may have peaked, the data show.