Abstract: Knowledge of reservoir fluid properties is very important in reservoir engineering calculations such as reserve estimates and numerical reservoir simulations. Laboratory measurements are the most dependable methods for pressure-volume-temperature (PVT) analysis of reservoir fluid properties. Under circumstances, the absences of such measurements are unavailable, hence, resorted to use empirical PVT correlations. Within the current research, a new correlation for estimating oil formation volume factor at bubblepoint pressure of Egyptian crude oils using nonlinear multiple regression technique has been developed. In developing the correlation, 162 PVT data sets from Egyptian crude oils were used. The data were collected from different fields in Egypt and covered a wide range of crude oils ranging from heavy to volatile oils. The data consisted of oils with oil formation volume factor at bubblepoint pressure ranging from 1.068 to 2.43 bbl/stb, oAPI of 17 to 46, solution gas oil ratio of 52 to 2254 scf/stb, gas gravity of 0.6 to 1.474 and temperature of 107 to 310oF. The developed correlation was taken as a function of solution gas oil ratio, oil gravity, gas relative density and reservoir temperature. Statistical and graphical analyses have been used to evaluate the performance of the developed correlation. Correlation performance was also compared with published correlations. It was found that the new correlation estimates oil formation volume factor at bubblepoint pressure of Egyptian crude oils much better than the published ones. The obtained outcomes include an average relative error (ARE) of 0.06, an average absolute error (AARE) of 2 and coefficient of regression (R2) of 0.98.In the current research, PVT data sets were collected from Egyptian reservoirs and regression analysis were used to obtain oil FVF correlation.
Keywords: PVT Correlations; Oil Formation Volume Factor; Egypt.