Multi-component mixtures that exhibit a liquid–liquid miscibility gap are of utmost importance for the oil and gas industries because of the prevalence of hydrocarbons and water in many processes. Here we present configurational-bias Monte Carlo simulations in the Gibbs ensemble to investigate the liquid-liquid and liquid-liquid-liquid equilibria for binary and ternary mixtures containing water/(n-decane or n-dodecane)/(2-butoxyethanol or ethanol). Analysis of the simulation trajectories yields a wealth of information on self-assembly and other microheterogeneous features present in the different liquid phases.