Disposal of flue gases in oil reservoirs with high-viscosity oil in order to increase oil recovery and improve the environmental situation

The reserves of highly viscous oils and natural bitumen are several times higher than the stocks of light oils. In the development of such oils by thermal methods, steam is produced, the development of which is accompanied by significant emissions into the atmosphere of flue gases, including carbon dioxide. According to estimates, the extraction of high-viscosity oils annually releases about 34.5 million tons of carbon dioxide into the atmosphere. However, carbon dioxide emissions from steam generation can be reduced to zero by injecting flue gases along with steam into the formation. In addition to environmental benefits, the technology of co-injection of water vapor and combustion gases (nitrogen and carbon dioxide) has a complex (thermal and physico-chemical) effect on the formation with a synergistic effect. The article is devoted to the analysis of the mechanisms affecting the increase in oil recovery during the co-injection of steam with flue gases, the description of equipment for the injection of flue gases into the reservoir, as well as the analysis of field experience in using this technology. The calculations for one of the fields of high-viscosity oil show the high efficiency of co-injection of water steam with flue gases. © The Authors, published by EDP Sciences, 2019.