Abstract: To tackle the problems of frequent steam channeling,shrinkage of steam swept volume,and low thermal-energy utilization caused by formation heterogeneity during heavy-oil steam flooding,a synergistic plugging technology combining temperature-resistant gel particles and nano-micron temperature-resistant gel was applied,and a functional plugging system with temperature resistance up to 260 ℃ was developed.Results show that the temperature-resistant gel particles have excellent thermal stability,strong deformability,and thermal coalescence behavior,allowing targeted plugging of large pore channels and high-permeability channels.The nano-micron temperature-resistant gel has low initial viscosity,strong mobility,and high plugging strength;it gels rapidly at high temperature and can effectively fill small channeling pathways.By injecting gel particles first to establish a plugging framework and then injecting nano-micron gel to fill gaps,a combined process achieves synergistic and efficient plugging of high-permeability and steam-channeling pathways.This technology was applied to a steamflood pilot well group in the Qi 40 Block of the Liaohe Oilfield.After plugging,no steam channeling occurred between steam-injection wells and surrounding production wells,and the staged cumulative incremental oil was 1 085 t,significantly improving steam utilization and thermal-recovery performance.This technology can provide effective technical support for managing steam channeling in similar heavy-oil reservoirs.

Key words: steam channeling, gel particles, nano-micron temperature-resistant gel, numerical simulation, heavy oil, steam flooding, Liaohe Oilfield