Investigation of Compositional Grading Models in Petroleum Reservoirs

Mohammad Hossain Nikpoor
Supervisor: Dr. John Chen


In this work the author use a non-isothermal model to predict compositional variation in a petroleum fluid column. At the same time, a non-isothermal model will be used to predict change of plus fraction molecular weight (and as a result all other its properties) with depth. The author investigates effect of several factors as mode of characterization, binary interaction coefficients, volume shifts and near-criticality on the change of physical properties like bubble point pressure, solution gas-oil ratio and oil formation volume factor. A computer program will be used to predict location of gas-oil contact and finally author shows how neglecting compositional grading (CG) can lead to serious errors in the calculated initial oil in place.Conclusively, a new algorithm for non-isothermal CG is developed and validated based on previous works in the literature. A new model for plus fraction change in the reservoir is developed and validated