A Nano-SiO₂-Based Core-Shell Hybrid as a Dual-Functional Viscosity Reducer and Pour Point Depressant for Heavy Oil

Area of Science:

• Materials Science
• Petroleum Engineering
• Chemical Engineering

Background:

• Heavy oil flow is hindered by high viscosity, poor mobility, and low-temperature behavior, particularly in waxy crude oils.
• Conventional polymer additives lack thermal stability, dispersibility in crude oil, and multifunctionality.
• Existing flow improvers face limitations in addressing the complex challenges of heavy oil transport.

Purpose of the Study:

• To develop a novel organic-inorganic hybrid flow improver for heavy oil.
• To enhance thermal stability, oil-phase dispersibility, and flow properties of heavy crude oil.
• To investigate the performance of a nano-SiO2-based nanohybrid in improving heavy oil viscosity and pour point.

Main Methods:

• Synthesis of a nano-SiO2-based organic-inorganic hybrid (NSDA) via in situ free-radical copolymerization.
• Modification of silica surfaces with 3-(trimethoxysilyl)propyl methacrylate (KH-570).
• Characterization of the nanohybrid structure, thermal stability, and dispersion in xylene.

Main Results:

• The synthesized NSDA exhibited a core-shell nanohybrid structure with enhanced thermal stability and oil-phase dispersibility.
• A viscosity reduction rate of 90.2% was achieved with 0.5 wt% NSDA in Liaohe heavy oil.
• A pour point depression of 11°C was observed, indicating improved low-temperature flow behavior.

Conclusions:

• The nano-SiO2-based organic-inorganic hybrid (NSDA) effectively improves heavy oil flow properties.
• The nanohybrid structure provides synergistic benefits for wax crystal regulation and viscosity reduction.
• NSDA offers a promising solution for enhancing heavy oil production and transportation efficiency.