Abstract: The channel sand reservoirs in the Tarim Basin are categorized as ultra-deep,high-temperature,and high-salt reservoirs,characterized by strong reservoir heterogeneity.Injected water tends to channel along the central part of the channel with better physical properties.To address this issue,physical simulation studies on swelling emulsion flooding were conducted using visualized micro-models and heterogeneous long-core models.The study analyzed the characteristics and mechanisms of flooding,optimized the flooding parameters and slug combination methods,and implemented in-situ applications.The results indicate that the remaining oil distribution types after water flooding in channel sand reservoirs mainly include multi-branch cluster,parallel throat,corner concave,dispersed isolated droplet,and contiguous blocky types.The flooding mechanism of the swelling emulsion involves deep migration+viscosity increase and pressure enhancement,swelling plugging+deformation migration and stripping oil film+push-pull dragging.The optimized flooding parameters are as follows:injection volume is 0.30 times the pore volume,mass fraction is 8%,emulsion particle size is in the micrometer range,injection rate is 0.52 mL/min,and the injection slug combination is 0.15 times the pore volume of small-particle-size lotion particles+0.15 times the pore volume of large-particle-size emulsion particles.In-situ applications demonstrate significant flooding effects,with the daily oil production of the flooding well group increasing to a maximum of 26.4 t and the water content decreasing to a minimum of 32.1%.The research achievement is of great significance for tapping the remaining oil potential in ultra-deep,high-temperature,high-salt channel sand reservoirs with strong heterogeneity.

Key words: swellingemulsion, profile control and flooding, ultra-deep reservoir, high temperature, high salinity, heterogeneity, channel sand