Modeling Reservoir Fluid Behavior near the Well Bore and its Implications for Sampling

Abstract

PVT properties are critical to petroleum reservoir characterization and management. They are a major requirement for the selection of production strategy, for production facility design, for reservoir simulation, and in enhanced oil recovery projects. This study investigates reservoir fluid phase behaviour at different pressure drawdown conditions in the near-wellbore region using modern reservoir simulation techniques and tools such as CMG and Eclipse. Khalifa University has a different set of PVT studies and reservoir information from an abandoned oilfield in the UAE and this was used as the basis of this study. After initial work with a compositional model, this research used CMGs WinProp package and Eclipse PVT Package (PVTi) to analyse the phase behaviour of the data set and simulate laboratory experiments in order to compare fluid samples for consistency. Then generate component properties for compositional simulations using GEM. Four different PVT lab reports were used in this research. The purpose of using more than one PVT report is to check the quality and consistency of the data that was measured in the lab then applied in different simulators. WinProp was found to be more accurate in matching the laboratory results. But PVTi was found to produce unacceptably high errors in this work. The two simulators used regression to tune the equation of state to match experimental results. Three of the PVT reports still had big differences between the gas oil ratio (GOR) reported by the lab and the gas oil ratio (GOR) calculated by the simulators before and after regression. The calculated GORs in both simulators were comparable in both cases, so it is suspected there were errors on the PVT data. Further work with CMG reservoir simulator showed that inaccurate PVT results and/or poor sample quality could affect modeling near wellbore fluid behavior.

Date of Award	Mar 2019
Original language	American English