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Abbreviation for sodium polyacrylate. SPA is the result of neutralizing a linear, anionic polymer made from the monomer acrylic acid, CH2=CHCOO- H+, with sodium hydroxide (NaOH). Polyacrylates are best utilized in soft water with low salinity to achieve the best dispersion and full chain elongation. Even low concentrations of hardness ions, for example, Ca+2, precipitate polyacrylates. Low molecular-weight polyacrylates are used as clay deflocculants. High molecular weight polymers are used for fluid-loss control and as a clay extender. As an extender, SPA is added to bentonite at the grinding plant. It is also used at the rig in low-solids mud. Divalent cations can negate its benefits as a clay extender. SPA is highly efficient when used to flocculate colloids in native-solids muds, clear-water muds and wastewater cleanup. The polymer chain links together colloidal solids that can be removed by gravity settling in shallow pits or by applying hydrocyclonecentrifuge or filtration techniques.

Alternate Form: sodium polyacrylate

See: acrylamide polymeracrylamide acrylate polymeracrylate polymeranioncalcium contaminationclear-water drillingdeflocculantdeflocculated mudflocculanthardness ionlow-solids, nondispersed mudnative-solids mudpeptized claypeptizing agentPHPA mudpolyacrylatepotassium mudsodium bicarbonatesodium carbonatesoft watervinyl polymerwater clarification