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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 150⁰F (66⁰C).

0.1% to 0.3% BWOC.

This retarder is effective only with Thixotrophic systems. It does not retard other cement systems.

P-DISS

Dependent on cement system and application.

1.0 to 3.0% BWOC in micro silica-extended slurries.

Fresh water and seawater and NaCl up to 37% BWOW (saturated).

This retarder is used in salt slurries requiring no fluid-loss control: P-DISS has a detrimental effect on fluid-loss control. P-DISS has a tendency to lead to premature viscosification (tertiary gel or false set). A dispersant alternative when unable to overcome secondary gelation in salt systems using conventional dispersants (P-DIS/P-DISL or P-EDISL).

P-LTR

Up to 200⁰F (93⁰C).

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 140⁰F (60⁰C). Dispersant generally enhances this performance.

P-LTRL

Up to 200⁰F (93⁰C).

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 140⁰F (60⁰C). Dispersant generally enhances this performance.

P-HTR

Alone from 125 to 250⁰F (52 to 121⁰C). Up to 310 ⁰F (154⁰C) with retarder aid P-RA.

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 200⁰F (93⁰C) range. It is less sensitive than P-UTR in the 200 to 220⁰F (93 to 104⁰C) range.

P-MTRF

130 to 250⁰F (54 to 121⁰C).

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

Alone from 125 to 250 ⁰F (77 to 146⁰C). Up to 310⁰F (154⁰C) with retarder aid P-RA.

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 of 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 200⁰F (93⁰C) range. It is less sensitive than P-UTRL in the 200 to 220 ⁰F (93 to 104⁰C) range.

P-TCRL

Alone from 175 to 300⁰F (79 to 149⁰C). Up to 375⁰F (191⁰C) with retarder aid P-RA.

0.01 to 0.5 gal/sk.

Fresh Water and seawater.

May be used in Thixotrophic systems using P-TTCL. May be detrimental to fluid-loss control at high temperature when used with retarder aid P-RA.

P-UTR

Alone from 200 to 300⁰F (93 to 149⁰C). Up to 350 ⁰F (177⁰C) with retarder P-HTD. Up to 400⁰F (204⁰C) with retarder aid P-RA.

0.05% to 1.0% BWOC.

Fresh water and seawater and NaCl up to 37% BWOW (saturated).

A powerful retarder. At the lower end of temperature range, thickening time is very sensitive to small variations in P-UTR concentration. May be dry blended or dissolved in mix water.

P-UTRL

Alone from 200 to 300⁰F (104 to 149⁰C). Up to 350⁰F (177⁰C) with retarder P-HTD. Up to 400⁰F (204⁰C) with retarder aid P-RA.

0.02 to 0.4 gal/sk. (0.1 gal/sk. P-UTRL equals 0.25% P-UTR BWOC).

Fresh water, seawater and NaCl up to 37% BWOW (saturated).

A powerful retarder. At the lower end of the temperature range, thickening time sensitive to small variations in P-UTRL concentration.

P-HTD/

P-HTDL

From 300 to 350⁰F (149 to 177⁰C) as a retarder aid.

Two parts P-HTD to one part P-UTR in difficult to disperse cements. One part P-HTD to two parts P-UTR in easy to disperse cements.

Fresh water, seawater and NaCl up to 37% BWOW (saturated).

This additive acts as a retarder and a dispersant. It extends the effective range of P-UTR to 350⁰F (177⁰C). P-HTD has good application in high-density slurries. May be dry blended or dissolved in mix water.

P-RA

Up TO 400⁰F (204⁰C) when used with P-UTR or up to 375⁰F (191⁰C) 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 of P-UTR to 400⁰F (204⁰C) and P-TCRL to 375⁰F (191⁰C). Often has a detrimental effect on fluid-loss control. May be dry blended only: Not soluble in mix water.

TABLE 1. RETARDER APPLICATIONS
RETARDERS	MAXIMUM RANGE (BHCT)	TYPICAL CONCENTRATION RANGE	MIX-WATER COMPATIBILITY	SPECIAL PROPERTIES/ CONSIDERATIONS
P-TCR	Up to 150⁰F (66⁰C).	0.1% to 0.3% BWOC.		This retarder is effective only with Thixotrophic systems. It does not retard other cement systems.
P-DISS	Dependent on cement system and application.	1.0 to 3.0% BWOC in micro silica-extended slurries.	Fresh water and seawater and NaCl up to 37% BWOW (saturated).	This retarder is used in salt slurries requiring no fluid-loss control: P-DISS has a detrimental effect on fluid-loss control. P-DISS has a tendency to lead to premature viscosification (tertiary gel or false set). A dispersant alternative when unable to overcome secondary gelation in salt systems using conventional dispersants (P-DIS/P-DISL or P-EDISL).
P-LTR	Up to 200⁰F (93⁰C).	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 140⁰F (60⁰C). Dispersant generally enhances this performance.
P-LTRL	Up to 200⁰F (93⁰C).	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 140⁰F (60⁰C). Dispersant generally enhances this performance.
P-HTR	Alone from 125 to 250⁰F (52 to 121⁰C). Up to 310 ⁰F (154⁰C) with retarder aid P-RA.	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 200⁰F (93⁰C) range. It is less sensitive than P-UTR in the 200 to 220⁰F (93 to 104⁰C) range.
P-MTRF	130 to 250⁰F (54 to 121⁰C).	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	Alone from 125 to 250 ⁰F (77 to 146⁰C). Up to 310⁰F (154⁰C) with retarder aid P-RA.	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 of 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 200⁰F (93⁰C) range. It is less sensitive than P-UTRL in the 200 to 220 ⁰F (93 to 104⁰C) range.
P-TCRL	Alone from 175 to 300⁰F (79 to 149⁰C). Up to 375⁰F (191⁰C) with retarder aid P-RA.	0.01 to 0.5 gal/sk.	Fresh Water and seawater.	May be used in Thixotrophic systems using P-TTCL. May be detrimental to fluid-loss control at high temperature when used with retarder aid P-RA.
P-UTR	Alone from 200 to 300⁰F (93 to 149⁰C). Up to 350 ⁰F (177⁰C) with retarder P-HTD. Up to 400⁰F (204⁰C) with retarder aid P-RA.	0.05% to 1.0% BWOC.	Fresh water and seawater and NaCl up to 37% BWOW (saturated).	A powerful retarder. At the lower end of temperature range, thickening time is very sensitive to small variations in P-UTR concentration. May be dry blended or dissolved in mix water.
P-UTRL	Alone from 200 to 300⁰F (104 to 149⁰C). Up to 350⁰F (177⁰C) with retarder P-HTD. Up to 400⁰F (204⁰C) with retarder aid P-RA.	0.02 to 0.4 gal/sk. (0.1 gal/sk. P-UTRL equals 0.25% P-UTR BWOC).	Fresh water, seawater and NaCl up to 37% BWOW (saturated).	A powerful retarder. At the lower end of the temperature range, thickening time sensitive to small variations in P-UTRL concentration.
P-HTD/ P-HTDL	From 300 to 350⁰F (149 to 177⁰C) as a retarder aid.	Two parts P-HTD to one part P-UTR in difficult to disperse cements. One part P-HTD to two parts P-UTR in easy to disperse cements.	Fresh water, seawater and NaCl up to 37% BWOW (saturated).	This additive acts as a retarder and a dispersant. It extends the effective range of P-UTR to 350⁰F (177⁰C). P-HTD has good application in high-density slurries. May be dry blended or dissolved in mix water.
P-RA	Up TO 400⁰F (204⁰C) when used with P-UTR or up to 375⁰F (191⁰C) 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 of P-UTR to 400⁰F (204⁰C) and P-TCRL to 375⁰F (191⁰C). Often has a detrimental effect on fluid-loss control. May be dry blended only: Not soluble in mix water.