Y Hamedi Shokrlu - Department of Chemical & Petroleum Engineering, Sharif University of Technology
R. Kharrat - Tehran Research Center, Petroleum University of Technology
M. H. Ghazanfari - Department of Chemical & Petroleum Engineering, Sharif University of Technology-Tehran Research Center, Petroleum University of Technology
S Saraji - Tehran Research Center, Petroleum University of Technology

In this paper a screening criterion for asphaltene deposition, de-Boer method, is modified and generated in a separate form for different reservoirs including oils with different API gravity, asphaltene content and extremity. The concept of refractive index is used to calculate the solubility parameter with the aid of PVT data and in consequence to improve the accuracy of stability predictions. Moreover, accuracy of the predictions was confirmed by colloidal instability index (CII) and Asphaltene/Resin ratio using SARA analysis data and also by the single point ASphaltene InStability Trend (ASIST) technique using titration data obtained from empirical/theoretical correlations. The results show good agreement between predictions and reality. Meanwhile, predictions were extended to the whole production life of these reservoirs.

Asphaltene, Resin, Onset, Screening criteria, Solubility parameter