Synergistic Effect of Salts and Methanol in Thermodynamic Inhibition of sII Gas Hydrates

•New data on gas hydrate phase equilibria in the presence of methanol, salts or mixtures of both inhibitors were obtained.•20 wt% methanol solution in water possesses inhibition power close to brine (18 wt% of salts).•20 wt% methanol + brine solution provides the same thermodynamic inhibition as 50 wt% of methanol.•Synergism allows the consumption of methanol to be significantly reduced in fields with highly mineralized brine.•It is necessary to take into account the possible precipitation of salts from concentrated methanol solutions.