A Guide to Retarders

TABLE 1. RETARDER APPLICATIONS
RETARDERS MAXIMUM RANGE (BHCT) TYPICAL CONCENTRATION RANGE MIX-WATER COMPATIBILITY SPECIAL PROPERTIES / CONSIDERATIONS
P-TCR Up to 150 F (66 C). 0.1% to 0.3% BWOC. This retarder is effective only with Thixotrophic systems. It does not retard other cement systems.
P-LTR 125 – 310 F (85 C). 0.1 % to 0.5% BWOC. Fresh water and seawater. Usually acts as a dispersant in slurries extended with bentonite. Can be sensitive to cement quality, causing gelation or long thickening times, especially in the range above 140 F (60 C). Dispersant generally enhances this performance.
P-LTRL 85 – 185 F (85 C). 0.1 % to 0.5% BWOC. Fresh water and seawater. Usually acts as a dispersant in slurries extended with bentonite. Can be sensitive to cement quality, causing gelation or long thickening times, especially in the range above 140 F (60 C). Dispersant generally enhances this performance.
P-HTR 220 – 400 F (204 C). 0.2% to 2.0% BWOC. Fresh water, seawater and NaCl up to 37% BWOC (saturated). This retarder is less sensitive to cement quality variations than less-refined lignosulfonates such as P-LTR. It performs more reliably than P-LTR in the 200 F (93 C) range.
P-MTRF 130 to 250 F (54 to 121 C). 0.05% to 1.0% BWOC. Above 0.5% BWOC, slurry becomes very viscous. Fresh water and seawater. P-MTRF has been used successfully in salt-saturated slurries, but its performance varies widely from cement to cement. A multifunctional retarder, viscosifier and fluid-loss additive. Calcium chloride destroys the fluid-loss control. May be dry blended or dissolved in mix water.
P-HTRL 220 – 400 F (204 C). 0.05 to .5 gal/sk. (0.1 gal/sk. P-HTRL equals 0.4% P-HTR BWOC). Fresh water, seawater and NaCl up to 37% BWOC (saturated). Should be added to fresh water first, before the addition °F NaCl. This retarder is relatively insensitive to cement quality variations compared to less refined lignosulfonates such as P-LTRL. It performs more reliably than P-LTRL in the 200 F (93 C) range.
P-TCRL Alone from 175 to 300 F (79 to 149 C). Up to 375 F (191 C). 0.01 to 0.5 gal/sk. Fresh Water and seawater. May be used in Thixotrophic systems using P-TTCL.
P-RA Up TO 400 F (204 C) when used with P-UTR or up to 375 F (191 C) when used w/ P-TCRL. Approximately three parts P-RA to one part retarder. Fresh water, seawater and NaCl up to 37% BWOW (saturated). Retarder aid. Extends the effective temperature range °F P-UTR to 4000F (204 C) and P-TCRL to 375 F (191 C). °Ften has a detrimental effect on fluid-loss control. May be dry blended only: Not soluble in mix water.