Compositions and methods for well completions

摘要

Cement retarders for well cements are based on hydrophobins. Hydrophobins are proteins or polypeptides that form hydrophobic coatings on surfaces. The size of the hydrophobins is preferably between about 100 and 350 amino acids, and the preferred hydrophobin concentration is between about 0.001% and 1.0% by weight of cement. Portland cement is the preferred well cement. Cement slurries containing hydrophobins are useful for both primary and remedial cementing applications.

主权项

1. A pumpable well-cementing composition, comprising an inorganic cement, water and a retarder, wherein said retarder comprises at least one hydrophobin;
wherein the hydrophobin concentration is between 0.001% and 1.0% by weight of cement.