HR®-4 cement retarder is a calcium lignosulfonate derived from wood. It can be used to retard all API classes of cement as well as Pozmix® cement.
HR-4 retarder is effective in wells with bottomhole circulating temperatures (BHCTs) up to 170°F (76.7°C). It can also withstand static temperatures up to 260°F (126.7°C). This broad performance range allows HR-4 retarder to be used in wells as deep as 12,000 ft.
Although HR-4 cement retarder has a dispersing effect on the cement slurry, it does not change slurry weight, volume, or water ratio. In addition, HR-4 retarder can provide the following benefits:
- Extended pumping time
- Early cement-strength development
- More predictable thickening time
- Improved slurry displacement rates at steady pressures