Two semi-empirical models of gas-liquid mass transfer in gas-liquid-liquid systems are presented, one for the case where the dispersed liquid phase has a positive spreading coefficient S>0, the other for S<0. The models are based on mathematical expressions inspired by assumed mass transfer mechanisms, which are different depending on the oil spreading characteristics. Model simulations compare well with experimental data (up to oil phase holdup phi similar to 0.1), managing to simulate the shape of the experimental curves of oxygen mass transfer enhancement factor E vs. phi for the air-water-heptane (S>0) and air-water-dodecane (S<0) systems, better than other models available in the literature.