Sand Mines Get Boost From Eagle Ford Shale
Almost every well drilled in the Eagle Ford shale is eventually completed using a method known as hydraulic fracturing. (The exception to that rule are some wells in Maverick County, drilled by Jadela, which used a new propane frac job process.) The process of hydraulic fracturing or “fracking” requires a proppant to hold the newly broken apart fissures in the shale open. Sand is one of the materials most commonly used as a frac proppant. Some oil and gas exploration companies are utilizing frac sand that is brought to the Eagle Ford Shale area by rail car from mines as far away as Wisconsin. Others are sourcing frac sand from within Texas, such as from mines near Brady. Below is a photo of a sand mine in South Texas, which is seeing an upswing in sales due to oil and gas drilling in the Eagle Ford. To be an ideal frac proppant, sand should be smooth and round, so when packed into underground fissures it does not block them.
Above: Open pit sand mine near Columbus.
One of the largest frac sand operations in Texas is located near the hill country towns of Brady and Voca. Brady frac sand, also known as hickory or brown frac sand, is a lower cost alternative to Ottawa sand. Ottawa frac sand is composed of 99.4% silica, and comes from the St. Peter sandstone formation that stretches from Minnesota to South Dakota. Brady frac sand comes from the Hickory formation, which is composed of a poorly cemented sand containing some clay, silt and other impurities. Frac sand mines such as the one in the photo below take this sand and crush it, screen out impurities, then wash and dry it for transport. Brady brown frac sand has a lower ISO crush resistance of around 5,000 pounds, but is a well rounded sand well suited for use as a proppant in most hydraulic fracturing operations. Resin coated frac sand is produced by some Texas companies. The resin coating gives the particles of sand a greater crush resistance under pressure. On any given day there is a steady stream of trucks hauling Frac sand south to the Eagle Ford Shale from the Brady. Sand companies are openly recruiting with billboards across the country to fill frac sand truck driver job openings.
It’s difficult for a photo to capture just how large this pile of sand at a frac sand mine near Brady, TX, really is. The large water truck in the lower right hand corner gives you some perspective.