Coarse-Grained Simulations of Polymer-Grafted Nanoparticles: Structural Stability and Interfacial Behavior

Area of Science:

• Petroleum Engineering
• Materials Science
• Computational Chemistry

Background:

• Polymer flooding enhances oil recovery but faces polymer degradation from shear, ions, and high temperatures.
• Polymer-grafted nanoparticles (PNPs) show promise for improved viscosity and stability compared to linear polymers.

Purpose of the Study:

• To simulate oil-PNP-water systems using dissipative particle dynamics (DPD) at the mesoscale.
• To assess the stability and behavior of PNPs in brine conditions relevant to oil reservoirs.
• To guide experimental research on PNPs for enhanced oil recovery.

Main Methods:

• Mesoscale simulation using dissipative particle dynamics (DPD).
• Studied linear and branched polyelectrolytes' response to salinity.
• Parameterized polymer-oil and polymer-water interactions for PNPs at the oil-water interface.

Main Results:

• PNPs achieve viscosity enhancement at lower concentrations than linear polymers.
• Graft morphology and interfacial behavior are sensitive to solvent conditions and salinity.
• Equilibrium location of PNPs in oil-brine systems is determined by grafting density and salinity.

Conclusions:

• PNPs demonstrate superior stability and efficiency for enhanced oil recovery compared to traditional polymers.
• DPD simulations provide valuable insights into PNP behavior under reservoir conditions.
• Grafting density and salinity are critical factors controlling PNP performance in oil-brine systems.