UNIVERSITY OF WISCONSIN River Falls
Since 2008, oil production in the United States has risen more than 90%. Advances in horizontal drilling and hydraulic fracturing have allowed for the production of oil from tight, nonconventional formations. Hydraulic fracturing involves high pressure injection of water with sand to fracture the rock allowing oil/gas to flow more freely to a well.
Frac sand is naturally occurring high purity quartz (>99%) sand (0.1 to 2.0 mm fraction) that must meet rigorous industry specifications. Within the industry, the sand is referred to as "Northern White" or "Ottawa White" sand. Image Credit: USGS
The Upper Midwest is a principal supplier of frac sand in the United States. The majority of frac sand is mined from ultra-mature Cambrian and Ordovician sandstone bedrock formations (Mount Simon, Wonewoc, Jordan, and St. Peter formations.) Wisconsin leads the nation in frac sand production. Most of the frac sand mines are located within or near the periphery of the 'driftless' area of west-central and southwestern Wisconsin - an area that was largely unglaciated, leaving bedrock formations close to the surface. Image credit: Wisconsin Geological and Natural History Survey & Data from: USGS Mineral Commodity Statistics