Delayed Swelling Polymer Microspheres for CO₂ Channeling Control under High-Temperature and High-Salinity...

Area of Science:

• Petroleum Engineering
• Materials Science
• Polymer Chemistry

Background:

• Gas channeling during CO2 flooding reduces oil recovery and CO2 storage efficiency.
• Existing polymer microspheres swell rapidly and uncontrollably, hindering deep transport and plugging in high-temperature, high-salinity environments.
• There is a need for advanced materials to manage gas channeling in challenging subsurface conditions.

Purpose of the Study:

• To develop CO2-triggered and delayed swelling polymer microspheres (DVP) for effective gas channeling control.
• To investigate the influence of monomer composition and cross-linker content on DVP properties.
• To evaluate the performance of DVP in enhancing oil recovery and CO2 storage.

Main Methods:

• Synthesized DVP using inverse microemulsion polymerization with DMAPMAm, NVP, and MBA.
• Investigated DVP morphology and swelling behavior in aqueous solutions under varying conditions.
• Evaluated gas channeling control capacity in an artificial core under simulated reservoir conditions.

Main Results:

• DVP swelling ratio increases with DMAPMAm and cross-linker content, up to 0.5% MBA.
• Aged DVP (8 days, 140°C, 15,000 mg/L brine) showed a swelling ratio of 2.50 (280 to 701 nm).
• DVP achieved 99% plugging efficiency in a fractured core (10 mD permeability) after in-situ aging.

Conclusions:

• Developed CO2-triggered, delayed swelling polymer microspheres demonstrate excellent performance in harsh environments.
• DVP effectively controls gas channeling, offering a promising solution for enhanced oil recovery and CO2 storage.
• This research provides a novel approach for designing advanced materials for subsurface applications.