Fly Ash 1 : (n). Drilling Fluids. The noncombustible residue from the burning of pulverized coal. Fly ash is pozzolanic and is frequently used to replace a portion of the cement and reduce its density
Schlumberger Ltd. (The World's Leading Supplier Of Technology, Integrated Project Management And Information Solutions to Customers Working in The Oil and Gas Industry Worldwide), Schlumberger Oilfield Glossary Cedex, France 2014. http://www.glossary.oilfield.slb.com/en/Terms/sym/ a.aspx, (Ergo - Brit) {766}