Study of the effectiveness of thermodynamic inhibitors of hydrate formation in conditions of complicated oil and gas production

Gas hydrates — crystalline compounds of water and gas (most commonly methane) that form at low temperatures and high pressures — can block flow in pipelines, posing risks to the operation of oil and gas fields. The aim of this work is to investigate the effectiveness of thermodynamic hydrate inhibitors in gas – water and gas – water – oil systems. The zones of hydrate formation and dissociation were investigated at pressures up to 200 bars and temperatures down to –40°C. The effectiveness of the inhibitors was evaluated using the isochoric method with stepwise heating; the influence of oil and gas composition on the formation of hydrate plugs was also analyzed. Thermodynamic inhibitors — methanol and monoethylene glycol (MEG) were used as hydrate formation inhibitors. Oil samples with different densities (0.78 and 0.85 g/cm³) were studied. It was found that the presence of oil reduces the hydrate formation temperature by 11°C. When 35% methanol was added to the gas – water – oil system within the studied temperature range, no hydrate formation occurred. In the case of denser oil (0.85 g/cm³), MEG showed lower efficiency compared to methanol due to poor solubility, low diffusion rate, mass transfer limitations, and other factors. The results obtained can be used to improve technologies for preventing hydrate formation during the operation of fields with complex oil and gas production.

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