Method for reducing fluid loss from oilfield cement slurries using vinyl grafted wattle tannin

摘要

A process for forming an oil well cement composition comprising: mixing cement and a vinyl grafted wattle tannin fluid loss additive, the vinyl grafted wattle tannin comprising a wattle tannin grafted with at least one vinyl monomer selected from the group consisting of: 2-acrylamido-2-methylpropanesulfonic acid and acrylamide, wherein the wattle tannin is present in an amount of between about 0.05 to about 14 weight percent based on actives, the 2-acrylamido-2-methylpropanesulfonic acid is present in an amount of between about 68 to about 99.95 percent, and acrylamide is present in an amount of between about 0 to about 18 percent, to form a cement blend; and mixing the cement blend with water.