HR®-7 retarder is a sodium lignosulfonate that can be used as a retarder and dispersant in all API classes of cement as well as Pozmix® cement.
HR-7 retarder can be used in wells with bottomhole circulating temperatures (BHCTs) between 110°F and 170°F (43°C and 77°C). This retarder’s dispersing capabilities are particularly useful in cements containing high gel percentages. In these slurries, HR-7 retarder decreases air entrainment. It can also be used to help control fluid loss in slurries that are subjected to high shear rates. Small amounts of HR-7 retarder can extend a slurry’s temperature range and yield a smoother, more uniform slurry. In addition, HR-7 retarder can provide the following benefits:
- Extended pumping times
- Early cement-strength development
- More predictable thickening times
- Improved slurry displacement rates at steady pressures