Abstract: In view of the severe heterogeneity of thermal stimulation with steam injection in heavy oil reservoirs, the poor development conditions of low-and medium-permeability layers, and the serious interference of steam channeling in high-permeability layers, a new KWF compound plugging agent was developed independently by indoor experiments where curing agent (inorganic salt), dispersant (bentonite) and coagulant (caustic soda) were added to the produced sand of the oilfield through. The new plugging agent was featured by adjustable curing time (3 to 300 h), and resistance to pressure of greater than 6 MPa and temperature of greater than 350 ℃. After the plugging agent was injected into the high-permeability steam channeling, the system was cemented with the formation rock and the sealing rate was more than 85%, without any damage to the low-and medium-permeability layers. The field application showed that the system effectively blocked the big pores and enhanced the oil production, and the cumulative oil production was increased by 1 057 t. The produced sand profile control technology not only solves the environmental pollution caused by produced sand, but also reduces the cost of thermal recovery of heavy oil, with great significance for improving the final recovery efficiency and commercial benefits of the oilfield.

Key words: ultra-heavy oil, produced sand, profile control, curing agent, steam channeling interference, development degree