1. n. [Drilling Fluids]
Also known as polyphosphate, a polymer made from an orthophosphate by dehydration with heat. Orthophosphates are phosphoric acid (H3PO4) salts, where one, two, or three of the hydrogen ions are neutralized. Sodium acid pyrophosphate (SAPP) is a clay deflocculant and treatment for cement contamination. For clay deflocculation, polyphosphates are limited by the temperature at which they hydrolyze back to orthophosphates, although several that performed up to 280 degF [138 degC] have been documented in the literature (see reference).
Reference: Sikorski CF and Weintritt DJ: "Polyphosphate Drilling-Mud Thinners Deserve Second Look," Oil & Gas Journal 81, no. 27 (July 4, 1983): 71-78.
Alternate Form: polyphosphates