CO2-Reactive Polymer Surfactant for Gas Channeling Control

The patent changes the chemical nature of the profile control agent from conventional water-soluble polymers to CO2-reactive polymers containing basic functional groups (amino, amidine, guanidine groups). These polymers undergo chemical parameter changes when reacting with CO2, forming carboxylate salts that increase viscosity and provide long-term stable plugging under CO2 flooding conditions, resolving the contradiction between duration and reliability of control.

The patent employs composite polymer structures combining hydrophobic segments (for CO2 reactivity and micelle formation) and hydrophilic segments (for water solubility and viscosity enhancement). This composite structure enables the material to simultaneously achieve long-term gas channeling control and stability in the harsh CO2 flooding environment by leveraging the synergistic effects of both components.

The patent extracts the unstable non-covalent physical association mechanism and replaces it with stable covalent chemical bonds. The CO2-reactive polymer contains basic functional groups that form covalent carboxylate salt bonds with CO2, creating a chemically stable viscosification system that is not susceptible to external factors such as mineralized formation water or residual oil dissolution, thereby achieving both strong plugging and system stability.

The patent introduces CO2 as a chemical intermediary that mediates between the polymer and the formation environment. The CO2 reacts with basic functional groups on the polymer to form stable carboxylate salt intermediates, which then self-assemble into worm-like micelles and three-dimensional networks. This intermediary mechanism provides stable covalent bonding while enabling controlled viscosification that resists external destabilizing factors.