Evaluation of the pre-existing fracture surface profilometry and mineral alterations on wellbore cement affected by CO2-Rich brine

Effective implementation of Carbon Capture and Storage (CCS) technology requires containment of injected CO2. The performance of structural closures overlying reservoirs targeted for CO2 storage relies upon the integrity of well-bore cements which is affected by CO2 interfaces. Microfractures within the well-bore cement and micro-annulus at the casing-cement and formationcement may cause to CO2 leakage through the surface and/or the aquifers. Thus, understanding CO2-induced changes to the imperfections in the cement matrix is vital for riskless and operative imposition of CCS. This evaluation correlates the mineral alteration and surface profilometry of wellbore cement affected by CO2. This paper presents an evaluation covering an interpretation and an association of the results of the previous studies performed on the same experimental apparatus. This evaluation depicts the relationship of artificial fractures’ surface profilometry and the mineral alterations of the cement matrix after exposing it to CO2-rich acidic brine flow. Surface profilometry results allowed quantification of changes of the roughness of fracture surface. XRD (X-ray Diffraction), ESEM (Environmental Scanning Electron Microscopy) and surface profilometry analyses results are consistent and indicate that the chemical processes taking place on the fracture surface upon contact with acidic brine resulting in the widening of the fracture.