What Is Fracking Sand in Hydraulic Fracturing?

Definition & Examples of Fracking Sand

Man pumping down lines on an oil drilling pad on a sunny day


Hoptocopter / Getty Images 

Fracking sand, or frac sand, refers to sand and similar small materials used during the process of hydraulic fracturing. It helps to prop open underground cracks in order to more easily extract oil and natural gas.

Fracking sand itself is a highly sought-after commodity these days, due to increases in hydraulic fracturing ("fracking") with advancements in technology. It's important to understand the role that frac sand plays in our current energy economy, along with some of the challenges it presents

What Is Fracking Sand?

Fracking sand is a proppant—a material used to prop open the underground cracks from which the oil and natural gas can then be harvested during the fracturing process. These rocky areas don't have enough pore space to allow fluids to flow to a wellhead and be brought to the surface. The fracking proppants are blasted under pressure into a shale well along with large quantities of water and other industrial fluids. This process allows oil and gas to break through the rock. 

Fracking is a method for extracting underground oil and natural gas from shale gas formations. It combines drilling techniques with the application of fracking fluid (which includes frac sand) at extremely high pressure to fracture underground shale formations and release oil.

Typical proppants include actual sand crystals, such as high-quality quartz sand with very durable and very round grains. Most frac sand is made from high-purity sandstone. The sand is then industrially coated with resin, ceramic crystals, or other suitable materials. It then is known as resin-enhanced sand.

An alternative to sandstone is tiny ceramic beads made from sintered bauxite or small metal beads made from aluminum. Most grains, or beads, of fracking ​sand are between 0.1 millimeters and 2 millimeters wide.

How Is Fracking Sand Used?

Some underground rock structures are not permeable enough to let the poll or natural gas trapped inside to flow freely. This is particularly common with shale rock, so drilling in shale or similar materials for these trapped hydrocarbons requires different methods.

Hydraulic fracturing has not only to create fractures and fissures in the rock but to keep those fissures open to allow the oil and natural gas to flow freely. In order to accomplish this, a specially treated water must be pumped into the rock under high pressure. The water is treated with chemicals and thickeners in order to allow it to carry frac sand. With frac sand in suspension, the water can crack open rocks and allow the oil to flow freely

According to the most recent numbers published by the U.S. Geological Survey, the average amount of proppant used for each well was between 4.1 million and 5 million pounds, on average. In some cases, this reached as high as 18 million pounds.

An estimated 69 billion pounds of fracking sand was pumped into the ground in the U.S. over the last three quarters of 2013 and the first quarter of 2014.

Health Side Effects of Fracking Sand

According to government warnings, exposure to high levels of fine quartz fracking sand can lead to silicosis and other respiratory problems for workers. The fracking industry acknowledges the hazards. The Occupational Safety and Health Administration (OSHA) updated new standards that became enforceable in June of 2018.

The new standards require employers to implement practices such as wetting down work operations to limit silica-containing dust that could be inhaled. Exposure is also is limited to permissible exposure limit (PEL) of 50 micrograms per cubic meter on average over an eight-hour shift.

Other Concerns With Fracking

As a whole, fracking is a highly controversial practice. Health concerns extend beyond immediate exposure of workers to silica to possible contamination of drinking water supplies and damage to local air quality. These can cause health problems for the population around the fracking site, including eye irritation, respiratory problems, and potential chemical exposure.

Environmental groups have expressed many concerns with fracking, as well. The sheer amount of water needed (often millions of gallons) for one well means diverting freshwater from other uses. Waste and pollution from the process can damage the land, making the soil uninhabitable for plant life. The process has also been tied to increases in methane in the atmosphere, a major contributing factor, scientists have noted, in relation to climate change.

Finally, many in communities where mining for frac sand occurs complain about the destruction of their land. Mining operations often level vast areas of bluffs, leaving behind enormous holes and disturbing local populations with construction noise.

Proponents of fracking, on the other hand, argue that many of these risks are relatively low. Many have also noted that the net environmental effect of mining natural gas resources is positive because it significantly reduces coal mining. These debates aren't likely to be resolved any time soon. Hydraulic fracturing currently accounts for the vast majority of oil and natural gas drilling in the U.S.

Key Takeaways

  • Fracking sand is an extremely durable, pressure-resistant sand used to prop open underground cracks in order to more easily extract oil and natural gas.
  • Fracking a single well can require millions of pounds of sand.
  • Hydraulic fracturing, or fracking, is a very controversial practice but now represents the primary means of oil and natural gas drilling in the U.S.