Synthesis and Migration-Plugging Performance of a Novel High-Temperature Resistant Epoxy-Based Profile Control Agent...

Severe steam channeling in heterogeneous heavy oil reservoirs severely restricts thermal recovery efficiency, as conventional conformance control materials cannot simultaneously achieve long-term high-temperature resistance and deep reservoir penetration. This work develops a high-temperature-resistant epoxy-based liquid microsphere system for deep profile control in heavy oil steam flooding. A triple thermal-stabilization strategy is constructed: imide chain extension to enhance backbone rigidity, benzoxazine-phthalonitrile grafting to form dense triazine crosslinked networks, and KH-550-functionalized nano-silica for synergistic reinforcement. FT-IR and ¹H NMR verify the successful incorporation of rigid imide and triazine structures. TGA confirms the optimal formulation exhibits less than 5% mass loss at 350 °C. Multi-segment sand-packed tube tests demonstrate favorable deep migration capacity with inter-stage pressure ratios below 4 across 5000-15,000 × 10^-3 μm² permeability, and the cured network retains over 95% plugging efficiency after 350 °C steam scouring. Dual-tube heterogeneous flooding delivers 12.05% incremental oil recovery, outperforming rigid inorganic particles. This system provides a high-performance candidate for deep steam channeling mitigation in heavy oil thermal recovery.