Novel Polymer Encapsulated Silica Nanoparticles for Enhanced Water Control in Tight Carbonate Oil Reservoirs

Strategic Insights -

Researchers at the China University of Petroleum (East China) have developed a novel polymer encapsulated silica nanoparticles (CM-NPs) that can effectively reduce water-cut in tight carbonate oil formations with multistage hydraulic fractures. The CM-NPs were prepared by graft polymerization and quaternization and were evaluated through various experiments, including SEM, XPS, wettability measurements, and core flooding experiments. The results showed that the CM-NPs can irreversibly alter the wettability of the core surface from hydrophobicity to hydrophilicity, leading to a significant reduction in water relative permeability by up to 60% and a minimal decrease in oil relative permeability at different stages of water saturation.

Key Takeaways:

  • The CM-NPs were prepared by graft polymerization and quaternization, resulting in a novel polymer encapsulated silica nanoparticles.
  • The CM-NPs showed excellent acid resistance and strong adsorption on the core surface, maintaining a long-term period of water control after acid fracturing in tight carbonate oil reservoirs.
  • The experiments demonstrated a disproportionate permeability reduction on relative permeability of the oil-water systems, with water relative permeability decreasing by up to 60% and oil relative permeability decreasing by less than 15%.
  • The CM-NPs were identified by SEM, XPS, wettability measurements, and core flooding experiments, which showed changes in the element compositions and microstructure of the core surface after introducing CM-NPs on the reservoir rock surface.
  • The research was funded by the National Natural Science Foundation of China (NSFC) and the Natural Science Foundation of Shandong Province.
  • The CM-NPs have the potential to improve the efficiency of oil recovery in tight carbonate oil reservoirs.

Statistics:

  • 60% reduction in water relative permeability
  • Less than 15% decrease in oil relative permeability at different stages of water saturation
  • 31191-31201 pages in the International Journal of Hydrogen Energy publication
  • 46 volumes in the International Journal of Hydrogen Energy
  • The CM-NPs have been evaluated through various experiments, including SEM, XPS, wettability measurements, and core flooding experiments.

Sources:

  • A Novel Polymer Encapsulated Silica Nanoparticles for Water Control In Development of Fossil Hydrogen Energy-tight Carbonate Oil Reservoir By Acid Fracturing. International Journal of Hydrogen Energy, 2021;46(61):31191-31201.
  • International Journal of Hydrogen Energy: www.journals.elsevier.com/international-journal-of-hydrogen-energy/
  • China University of Petroleum (East China): Ministry of Education, Key Lab Unconvent Oil & Gas Dev, Qingdao 266580, Shandong, People's Republic of China.