Biocorrosion causes huge economic losses to the oil and gas industry. Microbes such as sulphate-reducing bacteria (SRBs), acid-producing bacteria (APBs), methanogens, iron-reducing bacteria (IRBs), sulphate-oxidizing bacteria (SOB) are the critical drivers of souring, biofouling, clogging, pitting and bio filming. The use of seawater and wastewater for enhanced oil recovery further exacerbates biocorrosion. This increased biocorrosion is primarily observed in injection wells using the wastewater-seawater. Significant concentrations of biocides are injected to address this. These biocides eventually impose selective pressure on the inherent microbial community and result in the development of resistance against the active compounds. Hence never resulting in total clearance of microbes. Lower biocide efficacy is widely observed in oil and gas industries; however, this is seldomly studied. Molecular approaches are likely to play a significant role in identifying genes conferring biocide resistance and the genetic elements involved in their transfer across other microbial communities.