3D implicit modeling applied to the evaluation of CO₂ geological storage in the shales of the Irati Formation, Paraná Basin, Southeastern Brazil

Abstract

The Paris Agreement established global ambitious targets for reducing carbon dioxide (CO 2 ) emissions, requiring the rapid and extensive development of low carbon technologies, and one of the most efficient is CO 2 geological storage. Among the deep geological formations used for CO 2 storage, the shale layers have been a new emerging field with higher efficiency because they are abundant and have a high content of organic matter that is favorable for CO 2 retention. However, one of the challenges in evaluating a location for potentials reservoirs is the adequate geological characterization and storage volume estimation. The study evaluates the Irati Formation of the Paraná Basin based on wireline logs information within Southeastern Brazil, where most stationary sources of carbon emissions are located. Three-dimensional (3D) implicit modeling techniques were applied not only for volume calculation purpose, but also in the site selection stage, generating thematic 3D models indicating thickness, depth, structures, and distance to aquifer systems. The limestones, shales, and black shales of the Irati Formation were locally grouped into six units considering the geological composition and spatial continuity. Based on the 3D model and reservoir parameters, the organic-rich shale Unit E with a theoretical capacity of 1.85 Gt is considerable for CO 2 storage. The estimated CO 2 storage capacity is promising because it is higher than the total CO 2 locally produced, and it could support the implantation of new projects in this region.

Assessing the potential for CO2 storage in saline aquifers in Brazil: Challenges and Opportunities

“…26, , 27 Therefore, several CCS studies have already been developed in the Paraná Basin focusing on different types of geological reservoirs. Studies considering geological storage of CO 2 in the Paraná Basin focusing on the black shales of the Irati Formation were conducted by Weber, 28 Abraham‐A and Tassinari, 29,30 de Oliveira et al., 3,31 Rocha 32 . The Rio Bonito Formation composed of sandstones and shales 33 has most recently focused on CCS studies.…”

“…Although this number may vary significantly according to technological assumptions and changes in production from the considered sectors and even the introduction of new technologies (such as blue hydrogen), it is relatively simple to identify the order of magnitude of the capture potential. However, the Brazilian storage potential estimates remain unclear, with only a few studies focused on specific areas 3–5 or reservoir type 6 …”

“…2 Although this number may vary significantly according to technological assumptions and changes in production from the considered sectors and even the introduction of new technologies (such as blue hydrogen), it is relatively simple to identify the order of magnitude of the capture potential. However, the Brazilian storage potential estimates remain unclear, with only a few studies focused on specific areas [3][4][5] or reservoir type. 6 Identifying suitable geological contexts for CO 2 storage necessitates a set of properties: sufficient depth, sealing integrity, adequate storage capacity, and effective petrophysical reservoir properties.…”