Study on the technique of flue-gas detection and combustion state identification of in-situ combustion process.

In this study, the relationship between the flue gases and combustion state of In-Situ Combustion(ISC) were systemically studied by analysis of combustion mechanism, simulate static and dynamic oil flooding experiments. On-site detection gas method was established and used for the detection the content of O₂, CO₂, H₂S, CO, CH₄ in the flue gases. The results showed that the CO₂ content was higher than 10%, the O₂ content was lower than 3%, and the range from 70-85% of N₂ in the flue gases, it can be evaluated as high temperature burning state. The CH₄ content in the flue gases was higher than 30%, the heavy oil reservoir would undergo hydro-thermal cracking reaction and the corresponding wells were in the combustion preheating stage. The gases content was conducted to evaluated the combustion state and ensure the safety of underground production Well. Based on that, the identification of combustion state and application in the fire flooding industrial pilot area of Hongqian-1 Wellblock was further explained. The results showed that 67% of ignition wells were in high temperature combustion state, and other 25% wells were evaluated as stalled. This study provided technique support for scheme formulation and production dynamic control. [ABSTRACT FROM AUTHOR]