Direct adjustment of wax thermodynamic model parameter to micro Differential Scanning Calorimetry thermograms

Among the flow assurance subjects, wax deposition plays a major role. As exploration an oil production moves towards deeper water frontiers, longer tiebacks increase the risk of wax deposition, which is assessed through modeling. In modeling schemes, the phase behavior of solid wax is essential and it is available through either a measured solubility curve or through thermodynamic models. These thermodynamic models normally need tuning and, due to the experimental difficulties of measuring solubility curves for real fluids, are tuned to the wax appearance temperature (WAT). To reduce the uncertainties of adjusting a model to just one point, a procedure to directly simulate DSC curves from a liquid-solid thermodynamic model is proposed. This new strategy allows a full thermogram adjustment without going through the empirical integration of the experimental DSC. Experimental DSC thermograms and simulated curves are presented for five standard single wax mixtures. Then, the solubility curves obtained from the model are compared to the experimental literature data and the difference between simulated wax disappearance temperature (WDT), experimental WDT and experimental wax appearance temperature (WAT) are discussed.