Relevance. The efficient use of liquefied natural gas in the transportation sector is considered a key factor for achieving economic and ecological success, which can be ensured by accurate prediction of ageing under drainless storage. Aim. To develop a model to predict overall composition of weathered liquefied natural gas, its density and the boil off gas rate, in addition to estimate the required time to reach the maximum allowable working pressure in liquefied natural gas tanks, for a 57.2 m³ tank used in refueling stations without fuel delivery in drainless storage. Methods. The model used vapor-liquid equilibrium equations, material and energy balance equations with employing the Peng–Robinson equation of state to simulate the multicomponent two phases system under wide range of conditions. Results. Indicated that heavier hydrocarbons increase the boil-off gas generating because in the final stages of weathering the heavier hydrocarbons govern the dynamics of boil off gas, accelerating pressure growth rate, thus shortening the drainless storage period. Nitrogen concentration beyond 0,5% will generate more boil-off gas and increase nitrogen presence in boil off gas composition, which reduces its commercial quality while a slight increase in storage duration was noticed. The thermal mass of storage plays a crucial role in storage, initial filling levels up to 80% significantly extended the drainless storage duration and reduced boil-off gas formation in comparison with 50% initial filling levels, while the effect of liquefied natural gas composition is unnoticeable. Ultimately, this study provides a simple applicable mathematical model for the management of liquefied natural gas storage, reduces boil-off gas, and strengthening the safety through liquefied natural gas supply chain.