CO2 Storage Site Assessment in the Mugrosa Formation, Middle Magdalena Valley Basin: An Integrated Geocellular, Geomechanical, and Fault Seal Modeling Workflow

Abstract

Geological CO2 storage represents one of the main strategies for mitigating greenhouse gas emissions within the framework of global energy transition. This study presents an integrated workflow for assessing the geological CO2 storage potential of the Mugrosa Formation in the Middle Magdalena Valley Basin (Colombia). The methodology integrates multicriteria analysis, seismic interpretation, sedimentological and petrophysical characterization, three-dimensional geocellular modeling, geomechanical analysis, and fault seal evaluation using Shale Gouge Ratio (SGR) approach to assess reservoir-seal integrity and storage feasibility. Based on regional evaluation, two targets were selected: North and Central Structures. Seismic interpretation identified faulted anticline traps associated with reverse faults within a compressional regime, revealing different degrees of reservoir compartmentalization. Petrophysical characterization showed a predominance of clay-rich facies, with shale volume > 90% in some intervals, limiting reservoir quality and restricting storage potential to discrete sandy bodies. Reservoir intervals exhibit effective porosity from 13–15% and permeability between 500–800 mD. Geomechanical analysis allowed the evaluation of system stability under injection conditions, main faults are close to critical reactivation conditions, although they remain stable under moderate injection pressures. High SGR values (>0.75) suggest favorable fault-sealing capacity. Storage feasibility is controlled by the balance between reservoir quality, structural integrity, and geomechanical behavior. The integrated workflow provides a robust framework for subsurface integrity assessment and early-stage screening of geological CO2 storage prospects in structurally complex sedimentary basins.