Retarded cement compositions and methods for well completions

摘要

Cement retarders are based on blends of lignosulfonate compounds, borate compounds and gluconate compounds. The compounds are present in certain ratios that allow the retarders to operate at temperatures and pressures up to and exceeding about 176°C and 152 MPa. The retarders may also be provided in liquid form, improving their suitability for use at offshore wellsite locations.