Microbiologically-induced corrosion (MIC) accounts for 20-30% of all corrosion cases in the oil and gas industry [1,2]. The extended exposure of pipeline to various environmental conditions affect the integrity of pipeline leading to serious operational implications. Regular integrity assessment is required to understand and predict the pipeline’s susceptibility to microbial corrosion threat and provide proactive measures to control its impact. One case study investigated the microbiological and compositional properties of solid deposits collected from flooded pipe strings, which were subsequently exposed to the atmospheric conditions for 1-2 years. The analytical results indicated the presence of general heterotrophic bacteria at 106-107/g of deposits, and corrosive microbes (IOB+SRB+APB+MET) at 105- 106/g of deposits. The solid samples mainly comprised of Calcite [CaCO3] and various forms of silicates. In addition, iron oxides in the form of Magnetite ([Fe3O4]) were also detected, indicating corrosion as a result of pipe strings’ weathering. The results from the study provided insights for the potential microbial corrosion threat to the flooded pipes and the development of mitigation strategies to maintain the integrity of the pipe strings before construction.