There is no question that fracking has become the new standard for getting the most out of an oil or natural gas well. Two and a half years ago, 95 percent of wells were being fracked, and a total of about 82,000 such wells were operational in September 2013. With fracking occurring in 17 different states, the need has also multiplied for appropriate proppants, such as frac sand, to prop open those shale fractures deep underground. Fortunately, there are a number of locations around the US where frac sand is being mined and processed for use in the hydraulic fracturing of fossil fuel wells.
The Characteristics of the Best Frac Sand
The best frac sand has a number of very specific properties which make it more difficult to obtain than just taking a front loader and dump truck to the nearest beach. Frac sand must be very strong in order to withstand the pressure of gravity when the pressure of the fracking liquid is removed from the well. The sand grains must be of uniform size and round shape in order to flow easily into the shale seams when they are cracked open, without linking together and preventing the oil and natural gas from escaping into the main wellbore for extraction. The frac sand grains must also be light enough to be transported within the fracking liquid, and impervious enough not to disintegrate when immersed in that fluid.
The Locations of the Best Frac Sand
Fortunately for US fracking interests, there are a number of states with high quality frac sand in the US.
Wisconsin and Minnesota
Arguably the best frac sand in the US is found within bluffs of silica sandstone in the Upper Midwest that were once the sandy floor of an ancient ocean bed. 500 million years ago, the tidal flows slowly wore down these grains of silica, shaping them into uniform, strong, round, nearly perfect frac sand. That sea bed is now known as the St. Peter Sandstone, and, in Wisconsin alone, there were 115 frac sand mines and plants spread along the western and southern portions of the state in October 2013. In the southeastern portion of neighboring Minnesota, frac sand from the St. Peter and similar formations is being mined in nine different locations.
The frac sand mine owners in these states are quite different, however, perhaps because of the number of mines involved. In Minnesota, the mine owners are local companies, while in Wisconsin, major players from out of state have purchased multiple mines and processing sites. Superior Silica Sands, for example, is headquartered in Fort Worth, Texas, but owns plants in Clinton and New Auburn. Hi-Crush Partners of Houston, Texas, operates mines in Wyeville and Augusta, and is proceeding with plans to open a third mine location along the border between the towns of Whitehall and Independence. Houston’s EOG, which is primarily a drilling company, works a number of frac sand mining locations in Wisconsin, as well as a central processing plant. Wisconsin Industrial Sand, a subsidiary of Fairmount Minerals, owns three frac sand mining sites in the state.
The St. Peter sandstone belt extends into Illinois where, at the LaSalle anticline, the stone has been uplifted by geological forces, making it accessible to open pit mining. Sand has been mined in this area for 150 years for a variety of industrial uses. US Silica is active in this area—and in fact owns one of those historic sand mines—as is Missouri-based Mississippi Sand. Unimin, which is the largest quartz proppant producer in the world, has 44 mining and processing facilities in North America, including Illinois. With five mines in operation and three more proposed in 2013, frac sand mining is on the move in Illinois.
While Michigan ranks third in the US for industrial sand production, the frac sand boom has not been as prevalent in this area. Along the Great Lakes there are a large number of sand dunes, but these do not always contain frac sand quality granules. None of the major frac sand producers are listed amongst the eleven active sand dune mining sites, although a subsidiary of Fairmount Minerals, Technisand, owns three active sites.
Good quality frac sand is not limited to the Midwestern US. Another major source of sand is found in Texas, where the Hickory Sandstone Formation has been mined for decades by Texas Silica. Two types of sand are mined by this company. The first type, Fredonia, is comparable to much of the Midwestern frac sand. The sand grains of the second, Brady, are not as strong as the Midwestern quartz, but they are suitable for fracking situations which require slate closure pressures of less than 4500 pounds per square inch.
Both types of sand are also naturally much less expensive to transport to nearby drilling sites in the south and western US. Another major player in Texas is Fairmount Minerals, although their main presence in Texas is in the transportation business, with over a dozen terminals scattered across the state.
Activity in Other States
The hunger for frac sand has led most states to take a good look at their geological formations to ascertain whether they can join the fracking boom. Frac sand is being mined from Virginia to California, North Dakota to Florida. In fact, only 15 of the lower 48 US states have no frac sand activity. However, whenever possible, thoughtful mining companies are likely to choose established and proven frac sand grains for their fracking operations.