New correlations for prediction of viscosity and density of Egyptian oil reservoirs

Abstract

Density and viscosity are of the most important governing parameters of the fluid flow, either in the porous media or in pipelines. Ideally, viscosity and density determined experimentally in the laboratory on actual fluid samples taken from the field under study. However, in the absence of experimentally measured data, especially during the prospecting phase, or when only invalid samples are available, one can resort to empirically derived PVT correlations. Correlations are also needed for the calculation of multiphase flowing pressure gradients which occur in pipe. These calculations require the prediction of fluid properties at various pressures and temperatures. Even though laboratory measurements of these properties may be available as a function of pressure, they are usually measured under isothermal conditions. The behavior of these properties as a function of temperature is usually predicted by using empirical correlations. So it is of great importance to use accurate correlations to calculate the crude oil density and viscosity at various operating conditions. During the last decades, several correlations have been developed to estimate density and viscosity of oil at different reservoir conditions. However, these correlations may be useful only in regional geological provinces and may not provide satisfactory results when applied to crude oils from other regions since oil properties differ according to its source, origin and core type .Also, crude oil composition is complex and often undefined. Therefore, based on Egyptian oil reservoirs data; new correlations have been developed for predicting density and viscosity of dead and live crude oil. Validity and accuracy of these correlations have been confirmed by comparing the obtained results of these correlations and other ones with experimental data for Egyptian oil samples. Checking results of these correlations show that correlations developed by this study revealed more accurate results than the literature correlations.