Comparison of the Performance of Empirical Models Used for the Prediction of the PVT Properties of Crude Oils of the Niger Delta

Abstract

A review of the literature has revealed the lack of a formal analysis of the performance of empirical methods for the prediction of pressure volume temperature (PVT) properties of Niger delta crude oils. This study presents an assessment of the predictive accuracy of five bubble-point pressure (P _b ) correlations and five bubble-point oil formation volume factor (B _ob ) correlations against a large measured PVT data bank from Niger Delta crude oils. Statistical analysis techniques were used to evaluate the performance and the accuracy of the commonly used empirical models for estimating PVT properties of Niger crude oil in order to guide designers and operators in selecting the best correlations for their particular applications. Agreement between calculated and measured P _b and B _ob values for the various models was very poor. The model predictions of P _b and B _ob can be different from the measured values by 56% and 242%, respectively. Development of improved models for predicting the PVT properties of Niger delta crude oils is urgently required.

Keywords:

• empirical models
• Niger delta crude oil
• PVT properties
• statistical analysis

ACKNOWLEDGMENT

The authors are grateful to the management of the Department of Petroleum Resources (DPR) Nigeria, for providing the data used in this study.