Sensitivity analysis on polymer Solution theory modeling parameters of asphaltene precipitation

Thermodynamic models have not resulted in a global solution for asphaltene precipitation, therefore detailed study of model parameters to understand their effect on the results is necessary. A set of experiments have been conducted to study precipitation of asphaltene due to pressure drop. The precipitation tests include a set of PVT tests to characterize fluid samples, a set of filtration tests held at several pressures followed by IP143 standard test of asphaltene precipitation to measure the amount of asphaltene precipitation at different pressures with a new method. The tests have been done on two distinguished Iranian reservoir petroleum samples. The data have been used to model and investigate asphaltene precipitation in porous media. Effect of pressure on asphaltene precipitation has been studied using thermodynamic models. The experimental data were used to develop a thermodynamic regular polymer solution model to predict asphaltene precipitation due to pressure drop. As solubility parameter is the essential parameter in this model, Sensitivity analysis on effective parameters on asphaltene precipitation along with effect of changing EOS on asphaltene solubility parameter has been done. Moreover, Statistical nonlinear correlation has been used to predict asphaltene solubility parameter and find effective parameters in prediction of asphaltene solubility parameter in regular polymer solution models.