Abstract
The Paris Agreement established global ambitious targets for reducing carbon dioxide (CO2) emissions, requiring the rapid and extensive development of low carbon technologies, and one of the most efficient is CO2 geological storage. Among the deep geological formations used for CO2 storage, the shale layers have been a new emerging topic showing to be efficient because they are abundant and have a high content of organic matter, being favorable for CO2 retention. However, one of the challenges in evaluating a location for possible reservoirs is the adequate geological characterization and storage volume estimates. This research evaluated the Irati Formation of the Paraná Basin, through the information from hydrocarbon exploration wells in Southeastern Brazil, where most stationary sources of carbon emissions are located. Three-dimensional (3D) implicit modeling techniques were applied not only for the volume calculation purpose, but also in the site selection stage, generating thematic 3D models of thickness, depth, structures, and distance to aquifer systems. The limestones, shales, and black shales of the Irati Formation were locally divided into six units according to geological composition and spatial continuity. The E black shale unit was considered for CO2 geological storage indicating a theoretical capacity of 1.85 Gt of CO2. The potential of the achieved capacity is promising not only for been greater than the total of CO2 locally produced but also for supporting the implantation of new projects in this region.
CO2 Geological storage in saline aquifers: Paraná Basin caprock and reservoir chemical reactivity
