LIGNOSULFONATE-ACRYLIC ACID GRAFT COPOLYMERS AS SACRIFICIAL AGENTS FOR CARBON DIOXIDE FOAMING ABENTS

摘要

The invention is a method for improving conformanceduring a carbon dioxide foam flood, which comprises injectinginto the formation an aqueous solution of about 0.05% to about 5%by weight of a carbon dioxide foaming surfactant, and about 0.05%to about 5% by weight of a lignosulfonate-acrylic acid graftcopolymer having about 2% to about 70% by weight of acrylic acid,and injecting into the formation carbon dioxide to sweep thehydrocarbons towards a production well for recovery.