A correlation approach for prediction of crude oil viscosities

Abstract

The role of reservoir fluid viscosity for reservoir evaluation in performance calculations, planning thermal methods of enhanced oil recovery, evaluation of hydrocarbon reserves and designing production equipment and pipelines makes its accurate determination necessary. Reservoir oil viscosity is usually measured isothermally at reservoir temperature. However, at temperature other than reservoir temperature these data are estimated by empirical correlations. High dependency of oil viscosity on fluid nature and fluid source causes the unique application of these correlations to special cases from which they have been derived. Here, based on Iranian oil reservoirs data; new correlations have been developed for prediction of dead, saturated and under-saturated oil viscosities. These correlations have been derived using so many oil viscosity data. Validity and accuracy of these correlations have been confirmed by comparing the obtained results of these correlations and other ones with experimental data for so many Iranian oil samples. In contrast to other correlations which need so many specific parameters for oil viscosity prediction, this type of correlations need only some field data which always are available. Checking the results of these correlations shows that the obtained results of Iranian oil viscosities in this work are in agreement with experimental data compared with other correlations.