Aiming at the problem of high water content and low degree of recovery of low permeability heavy oil reservoir in Guan128 block of Dagang Oilfield, the microscopic seepage law and residual oil characteristics of viscosity reducers flooding were studied through indoor experiments, and the planar wave and characteristics and residual oil distribution law were quantitatively analysed with the help of AI intelligent recognition. The experimental results show that after the viscosity reducer emulsification of crude oil, the emulsion aggregates and can block the water-driven flux channels, the advantageous transport channels of oil droplets increase, improve the wave and reach coefficient, and reduce the oil saturation. AI image identified pore throat droplets of oil, the wall membrane oil, the residual oil in the dead corner and the residual oil without wave and flake oil and other types of residual oil distribution, and the formation mechanism was analyzed, and measures of surfactants injection and encryption of the network of wells were put forward, and the blocking of high seepage channels was adjusted. Adding viscosity-reducing agent system can reduce the starting pressure gradient and improve the fluidity of heavy oil. After the conversion of water drive to chemical drive, the oil washing effect of residual oil in the pores and throat and residual oil in the dead space is improved, and the recovery rate is increased by 15.28%. The research results provide important theoretical reference for the research on the mechanism of efficient oil enhancement and field application of viscosity-reducing agent injection in the late stage of water-drive development of low-permeability heavy oil reservoirs.
| 科 Family | 属数 Number of genus | 种数 Number of species | 占总种数比例 Percentage of total species (%) | 属 Genus | 种数 Number of species | 占总种数比例 Percentage of total species (%) |
|---|---|---|---|---|---|---|
| 鹅膏菌科Amanitaceae | 2 | 11 | 5.26 | 鹅膏菌属 Amanita | 10 | 4.78 |
| 小菇科 Mycenaceae | 2 | 12 | 5.74 | 丝盖伞属 Inocybe | 5 | 2.39 |
| 多孔菌科 Polyporaceae | 8 | 14 | 6.70 | 蜡蘑属 Laccaria | 5 | 2.39 |
| 红菇科 Russulaceae | 3 | 23 | 11.00 | 小皮伞属 Marasmius | 6 | 2.87 |
| 小菇属 Mycena | 11 | 5.26 | ||||
| 光柄菇属 Pluteus | 5 | 2.39 | ||||
| 红菇属 Russula | 17 | 8.13 | ||||
| 栓菌属 Trametes | 5 | 2.39 |