Study On Factors Affecting Combustion Stability Of THAI Fire Flooding

THAI fire flooding is a new type of thermal recovery technology with great potential,but due to its complex oil displacement mechanism,it is difficult to maintain stable combustion for a long time in mine experiments.Relevant data show that many factors have a great impact on the combustion stability of fire flooding,but the law of its influence is still unclear.Therefore,this paper has carried out preliminary exploration on this issue.In this paper,the one-dimensional combustion tube and three-dimensional THAI fire flooding experimental device are used respectively.The single factor analysis method is used to conduct experimental research on the factors such as permeability,oil saturation,injection-production well spacing and gas injection velocity.The experimental data of temperature field change,output gas component content change and recovery factor in the process summarize the effects of various factors on the combustion stability of fire flooding,and the numerical simulation software(CMG)is used to simulate the physical model experiment.Through the results of one-dimensional combustion tube experiments,it can be seen that under too low permeability and oil saturation conditions,high-temperature combustion reactions of fire flooding cannot be stably occurred,within a certain range,large permeability and large oil saturation is more conducive to the combustion stability during fire flooding;through the results of three-dimensional THAI fire-flooding experiments and numerical simulation experiments,it can be seen that in the THAI fire-flooding process,the appropriate injection-production well spacing is selected.And gas injection speed is the key to ensure stable combustion.Under the THAI fire flooding experimental device and experimental conditions,the length of X range from 6cm to 8cm and length of Y range from 9cm to 12 cm,which is the best value range of injection-production well spacing.The best gas injection rate is about 10L/min.The research results of this paper have certain reference significance for the design of on-site development schemes.