SCR-500™ retarder is usually supplied as powdered form, but a liquid solution, SCR-500L™ additive, is also available. SCR-500 and SCR-500L retarders are a synthetic material designed for temperature applications above 200°F (93°C). When cement slurries are exposed to extreme temperature fluctuations across long intervals in high-temperature wells, either SCR-500 or SCR-500L retarder can provide more stable and consistent thickening times than other high-temperature retarders. As a synthetic material, either can develop strength more quickly than lignosulfonate retarders and has a better batch-to-batch reproducibility. Either is especially suitable for cementing jobs with wide temperature ranges in which compressive strength must be developed at temperatures much lower than the bottomhole circulating temperature (BHCT). Either can be used alone at BHCTs as high as 330°F (166°C), but should be intensified with HR®-25 additive if used at temperatures higher than 330°F (166°C).
When SCR-500 or SCR-500L retarder is added to a slurry, the thickening time is directly proportional to the retarder concentration (linear concentration response). The thickening time, however, of a slurry containing either retarder decreases proportionally as temperature increases (linear temperature response). The low sensitivity of either retarder makes it especially effective between 210°F (99°C) and 240°F (116°C), a range at which high-temperature retarders are very sensitive to small concentration changes and low-temperature retarders are not effective.
Both SCR-500 and SCR-500L retarders are compatible with the following additives:
A synthetic cement retarder designed for use in cement with bottomhole circulating temperatures between 200°F (93.3°C) and 330°F (165.5°C), produces a linear response between concentration and thickening time