Depleted oil and gas fields are favorable targets for Carbon capture and storage (CCS) projects. Wellbore cement serves as a barrier between different zones in the subsurface and between surface and subsurface as well. The fractures inside wellbore cement sheath impair the effective sealing of the wellbore cement. Hence, the existence of microfractures poses a risk for CCS. The purpose of this experimental study is to gain understanding about the effect of acidic brine on the behavior of cement fracture and porosity. Two experiments were conducted. There were 2 mechanisms working...