Modelling Well Performance in Niger Delta Reservoir using Tuned Vertical Lift Performance (VLP) Correlation

Abstract

Well performance modelling is an intrinsic part of petroleum engineering study. It is a combination of the produced fluid PVT model, the reservoir IPR model and the VLP model. It involves modelling the pressure losses encountered by the reservoir fluid as it flows from the bottomhole to the surface. Many investigators have developed different correlations to model these pressure losses but none has been found to be the most accurate because fluid flow in the tubing is usually multiphase and very complex. In this work multiphase flow correlations were modified by tuning to fit the measured downhole pressure and rate from the production test using prosper in order to model the performance of the well under study. Thus, results from production tests are required to tune the correlation to match the observed behaviour. Results showed that the well performance is dependent on the reservoir pressure, tubing head pressure (THP), tubing size and water cut. From the case study, it was observed that the well will not flow if left at its present condition (250psig THP, 30%water cut, 2.875” tubing size) at reservoir pressures below 2900psig. Reducing the THP (to about 200psig) as well as the tubing size results in increase in production.