Physical Simulation of Wet Combustion of High Viscous Oil by Hong Qian Fire Flooding

Using the physical simulation technology of fire flooding combustion pipe, the feasibility of wet combustion was studied on high viscosity oil (μ ≥ 40000 mPa·s) in the Hong Qian 1 well area of Xinjiang Oilfield; The influence of water injection on the combustion effect is determined by calculating the combustion area and the propulsion speed of the fire line; The key parameters such as water injection time and water/air ratio of wet combustion are further optimized, and the optimal water injection water for the implementation of wet burning scheme on site is determined by combining theoretical calculation. The results showed that the minimum spontaneous ignition temperature of high viscosity oil was 220 °C, the maximum combustion temperature was 650– 700 °C; The low-temperature oxidation reaction occurred at 220–400 °C, and the high-temperature oxidation reaction occurred above 400 °C; During the dry combustion process, the dimensionless standard deviation of pressure and gas injection σ were greater than 15%, indicating that the combustion stability was poor and the blockage was easy to occur when the live wire advanced near the middle of the model (x = 42 cm); The dry firing line propel velocity vD and the wet firing line propulsion velocity vW are negatively and linearly correlated with the axial position; After water injection, vW increases rapidly and then decreases linearly along the axial position; TW > TD in the range of 20–40 cm of the combustion leading edge, and at the back of the model (x ≥ 42 cm) Tw,max > TD,max, indicating that wet combustion can effectively expand the combustion wave area and reduce viscous resistance; The maximum value of the water/air ratio wmax = 8748 L/104 m3; The best time for water injection in wet combustion is to advance the firing line to 24 cm, and the optimal water/air injection ratio is 3000 L /104 m3.