Evaluation of Empirically Derived PVT Properties for Iranian Crude Oils

PVT properties are important parameters in reservoir engineering. Correlations are used whenever experimentally derived PVT data are not available and data from local regions are expected to give better approximation to estimated PVT values. This paper evaluates the most frequently used empirical black oil PVT correlations for application in Iran. As it will be discussed Empirical PVT Correlations for Iranian crude oils have been compared as a function of commonly available PVT data. Correlations have been compared for: • Bubble point pressure, • Solution gas oil ratio at bubble point pressure, • Oil formation volume factor at bubble point pressure, Often, these properties are required for oil field computations when there are no experimental or laboratory measurements available. When only oil and gas gravities, reservoir pressures, and temperature are available, it is imperative to use published correlations for making accurate estimates of the fluid’s physical properties. For comparison correlations, we have covered a wide range of data. More than three hundred pressure-volume-temperature (PVT) reports from Iran have been used in the comparison correlations. Some of the published correlations, Standing, Petrosky and Farshad, Glaso, Marhoun, Hanafy, Dokla, and Dindorak were tested using data set. The PVT correlations can be placed in the following order with respect to their accuracy: (1) For bubble point pressure; Al-Marhoun, Standing, Hanafy, Dindoruk (2) For the oil formation volume factor; Petrosky, Standing, Glaso, Dokla, Al-Marhoun, Hanafy (3) For solution gas oil ratio; Standing, Al-Marhoun, Dindorak, Glaso, Petrosky Error bounds of the obtained correlations are calculated and compared to Iranian crude oils. All reservoir fluid property correlations available in the petroleum engineering literature were compared with this database.

Keywords:

PVT correlations , bubble point pressure , solution gas oil ratio , oil formation volume factor