Microbial enhanced oil recovery (MEOR) methods apply injection of bacteria to depleted oil reservoirs to produce oil, which had remained unrecovered after the conventional methods of production. The ability of thermophilic anaerobic bacteria to produce gas as the main mechanism in potential MEOR in high salinities of 70–100 g/L was investigated in this study. Maximum gas production of up to 350 mL per 700 mL of salty solution was produced at a salinity of 90 g/L stably during 2–4 days of experiment. The experimental results were upscaled to the Snorre Oilfield, Norway, and simulated using ECLIPSE software for 27 months. The best scenarios showed that the increase in oil recovery on average was at 21% and 17.8% respectively. This study demonstrated that anaerobic bacteria used in biogas plants could be an attractive candidate for MEOR implementation due to their ability to withstand high temperature and salinity, and produce gas in large volumes.