Thermodynamic Analysis of Alternating Cyclic Steam and Flue Gas Injection for Colombian Heavy Oils

Thermodynamic efficiency indicators of equipment for alternating cyclic steam and flue gas injection to increase oil recovery and reduce adverse environmental impact were analyzed applied to Colombian heavy oils production. The equipment consisted of two subsystems: steam generation and flue gas compression. The energy carrier parameters were chosen based on the depth of the producing wells and the experimental data provided by the Colombian partner. The thermodynamic analysis involved estimation of exergy losses of the subsystems operating both separately and jointly to ensure alternating cyclic steam and flue gas injection. Various steam to flue gas injection ratios were examined over a five-day cycle. It was found that the efficiency of integrated subsystems, which is determined by minimum total exergy losses, differs drastically, depending on whether centrally or locally generated electric power is used. It was concluded that, in addition to the thermodynamic analysis, it is essential to conduct an economic analysis of the variable part of the reduced costs for implementation of the alternating cyclic steam and flue gas injection process. Economic calculations showed that the optimum technological solution would be use steam and flue gas injection ratios of 4.5:0.5 in a 5-day cycle as well as a centrally generated power supply source is used.