Preparation of CO₂ responsive nanocellulose gel for mobility control in enhanced oil recovery

Abstract

The carbon dioxide (CO₂) injection is the promising enhanced oil recovery technique used in low permeability reservoirs. The presence of high permeability fractures along the matrix leads to poor sweep efficiency and gas channeling effect. The CO₂ responsive mobility control gels could be a potential solution to mitigate the gas channeling effects. This work showcases the straightforward method to prepare a CO₂ responsive gel by mixing aqueous suspension of nanocellulose and ethylenediamine. The addition of CO₂ leads to protonation of amine which enhances the ionic strength of the solution. This promotes the agglomeration of nanocellulose to form gel. The rheological properties of the gel were studied and found to have interesting mechanical property. And the micromodel is used to visualize the mobility control phenomenon of the as prepared gel. The core flooding experiment proves that the synthesized gels were effective in low permeable cores.

Graphical abstract

Keywords:

• Nanocellulose
• mobility control
• CO₂ responsive gel
• enhanced oil recovery
• core flooding

Additional information

Funding

This work was financially supported by national natural science foundation of China (grant number 21427812) and the “111 Project” (B13010).