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 1, 2 or 3 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°F [138°C] 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.