the definition and monitoring of reactants is not feasible in this collective approach,and therefore,the kinetic modelling is based on the fraction of maximum expelled oil generated (denoted as X)at a given time and temperature. figure 3 show the arrhenius plots that rusult when a first-order reaction rate is assumed for the generation of expelled oil.Regardless of the internalcomlexity of this overall reaction , the arrhenius plots show good linear relations that encourage their extrapolation to lower temperature regimes within the natural system.