SENSITIVITY STUDY OF THE RESERVOIR FLUIDS PVT PROPERTIES CALIBRATION ON SUPERFICIAL VELOCITIES AND LIQUID HOLDUP

Abstract

The upward two-phase flow is encountered in many applications in petroleum industry as it is in nuclear and chemical industries. This kind of flow depends on several factors as flowing pressure and temperature, PVT properties of reservoir fluids, trajectory of well, well completion etc. The PVT properties of fluids can be determined in laboratory based on oil and gas samples or can be estimated with different correlations. However, these correlations often lead to different results that are far from the measured data. The good practice is to calibrate a PVT correlation based on measured data in order to obtain a model which matches these data. In our paper, we investigate how the calibrated and non calibrated PVT properties of reservoir fluids influence the superficial velocities of fluids and holdup fraction in the case of the upward two-phase flow through the tubing string. In the first stage, we study the differences between calibrated and non calibrated values of oil PVT properties which influence the superficial velocities and liquid holdup. Then, we determine the superficial velocity of the fluids and the liquid holdup based on of the calibrated and non calibrated PVT properties of fluids. The general conclusion in our studied case is that the differences between the values of the superficial velocities and the liquid holdup calculated with the calibrated, respectively non calibrated PVT properties of fluids are not very large. However, it is better to calibrate the PVT properties of the fluids in order to minimize the errors that will propagate in the calculation of the pressure gradient.

Keywords

• holdup fraction
• upward two-phase flow
• superficial velocity
• pvt properties