Product Introduction Crosslinkable PHPA Powder Candidate for Lost-Circulation Control The TDS describes possible crosslinking with multivalent ions and blocking of formation gaps, but reaction and placement are formulation-specific. BLUFLOC powder PHPA is described in the supplied family TDS as a water-soluble copolymer of anionic character used in drilling-fluid and selected oilfield applications. The four powder grades span very-high and ultra-high molecular-weight classes