Thermodynamic Analysis of Alternating Steam and Flue Gas Injection Process in Application to Heavy Oil Fields in Colombia
This paper presents the thermodynamic analysis of the cyclic steam and flue gas injection process in application to heavy oil production for Colombian oilfields in order to improve oil recovery as well as reduce the environmental impact. The process comprises two subsystems: the steam generation subsystem and flue gas compression process. Working fluid parameters were selected based on the depth of the producing wells and the experimental data provided for Colombian oilfields. As part of the thermodynamic analysis, exergy losses were calculated for the subsystems operating separately as well as together in the cyclic flue gas-steam alternating injection process. The analysis was conducted for varying ratio between the duration and steam and flue gas injection over a five-day cycle. Is was determined that the efficiency of the subsystems operating together in the process (which is achieved by minimizing the total exergy losses) is drastically different depending on whether centralized power or local power generation is used for energy supply. It was concluded that an economic analysis is required in addition to the thermodynamic analysis. The varying part of the relative costs for the cyclic steam-flue gas injection process was assessed and it was shown that the optimal solution would be steam-flue gas injection with an injection ratio of 4.5:0.5 (for a five-day cycle) that uses a centralized power source.