The Asphaltene Stability Evaluation and Artificial Lift Timing Analysis for B Oilfield, Iraq

Abstract

During the oilfield development process, asphaltene may be destabilized and subsequently precipitate due to changes in temperature, pressure and the chemical composition of the crude oils, which can negatively affect oil production and reduce ultimate oil recovery factor. Hence conducting an accurate evaluation on the asphaltene stability during production operations has been very crucial to avoid the development issues caused by asphaltene precipitation. In this study, series of evaluation methods are first used to assess the asphaltene stability of Iraq B Oilfield and the results show that the asphaltene will easily precipitate as the formation pressure decreases. Furthermore, three sets of iso-thermal depressurization tests are performed in order to determine the specific asphaltene onset pressure (AOP). The asphaltene precipitation envelope (APE) is then plotted and tuned to match the AOP. Finally, the APE graph is used to determine the reasonable artificial lift timing for natural flow wells by nodal system analysis method. This new method to determine artificial lift timing can effectively maintain oil production and avoid asphaltene precipitation in reservoir.KeywordsAsphaltene stability evaluationAsphaltene precipitation envelopeArtificial lift