(n.) Drilling Fluids. The stress that must be applied to a material to make it begin to flow (or to yield). Yield stress is a parameter in the Herschel-Bulkley rheological model. See: Herschel-Bulkley fluid, yield point
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}