The invention relates to a method and system of preparing a lean methane-containing gas stream (22), comprising: —feeding a hydrocarbon feed stream (10) into a separator (100); —withdrawing from the separator (100) a liquid bottom stream (12); —passing the liquid bottom stream (12) to a stabilizer column (200); —withdrawing from the stabilizer column (200) a stabilized condensate stream (13) enriched in pentane, —withdrawing from the stabilizer column (200) a stabilizer overhead stream (14) enriched in ethane, propane and butane; —splitting the stabilizer overhead stream (14) according to a split ratio into a main stream portion (15) and a slip stream portion (16), —passing the slip stream portion (16) to a fractionation unit (300) to obtain an ethane enriched stream (17) and a bottom stream enriched in propane and butane (18).