The Process of Fracing Sand
Fracing sand refers to small materials (such as sand) used in the process of hydraulic fracturing. Hydraulic fracturing is a method for extracting natural gas found underground in shale gas formations. The sand is used as a proppant to prop open the underground cracks from which natural gas is harvested during the process. Some of these gases include natural gas liquids, oil, and natural gas that are found in the rock units. Fracing is necessary because many of the rock units do not have enough pore space to allow fluids to flow to an oil well. Proppants are shot under high pressure into a shale gas well with large quantities of industrial fluids and water to stimulate gas production and allow gas to flow to the well.
What is Frac Sand?
Sand and high-quality quartz sand are used as proppants. The sand must be very roundly grained and durable due to the high pressure that is used in the fracing process. The sand to be used for fracing is then coated with ceramic crystals, resin, or other materials to create a resin-enhanced sand. Some providers choose to use sandstone, sintered bauxite or small beads made from aluminum. The material used for fracing is typically between 0.1mm-0.2mm in width.
How is Frac Sand Used?
Underground rock often lacks permeability, which prevents oil from flowing to a well. Organic shale contains large amounts of oil and natural gas, so hydraulic fracturing was used to help solve this issue. By drilling a well into the rock, pumping water under high pressure into the well, and sealing the portion of the well in a petroleum-bearing zone, fractures in the rock will be generated so oil can be extracted. The water that is used for blasting is often treated with guar gum (as a thickening agent) and other chemicals to create a suspension for the frac sand to be suspended in.
Frac Sand Statistics
It is estimated that each shale gas well requires around 5 million pounds of sand or other proppants for the hydraulic fracturing process. Depending on the specific geological variations and characteristics of a shale formation, this number can range from 2.5 million to 7 million pounds. It is estimated that over 100 billion pounds of frac sand were pumped into the ground in the United States in 2018 alone.