A granular substance (sand grains, aluminum pellets, or other material) that is carried in suspension by the fracturing fluid and that serves to keep the cracks open when fracturing fluid is withdrawn after a fracture treatment
O'Brien Energy Company, Oil and Gas Exploration and Production, Glossary, LA, USA 2014. http://www.obrienenergyco.com/glossary/, (Oil - Amer) {781}