Integrated environmental risk assessment and climate resilience framework for water-saturated reservoirs: A petrophysical approach with cross-continental applications

¹ Peoples' Friendship University of Russia named after Patrice Lumumba, Moscow, Russia
² Nnamdi Azikiwe University, Awka, Anambra State, Nigeria
³ Pan African University of Life and Earth Science, Ibadan, Nigeria
⁴ Chukwuemeka Odumegwu Ojukwu University, Anambra State, Nigeria

^* Corresponding author: okeke_s@pfur.ru

Abstract

This study explores the dual benefits of carbon capture and storage (CCS) and geothermal energy from water-saturated reservoirs in the Seloken field, Chad Basin, Nigeria. A relative analysis with insights from Russia’s West Siberian Basin was made. Petrophysical analyses used well-log data to characterize three formations. CO₂ storage capacity, geothermal output, and seal integrity were analyzed. Porosity (Ø = 22–31%), water saturation (Sw = 96–100%), and shale volume (Vsh = 1.3–6.5 API) were obtained. The Kerri-Kerri Formation is the best CCS option with high porosity (31%) and net thickness (270–500 m), though its storage capacity is lower than the Achimov Formation (West Siberia) due to thinner seals. Geothermal potential (1.2-2.0 MW/km²) was identified in reservoirs with high bulk volume water (0.277-0.299). Microbial-induced calcite precipitation (MICP) was recommended to enhance sealing units. The Kadaru-1 well was identified as suitable for hydrogen storage. These findings highlight the role sedimentary basins could play in GHG reduction. The work provides actionable insights to help achieve Nigeria’s Nationally Determined Contribution (NDC) by adopting relevant Russian Federation best practices for sustainability.