On the Advection-Upstream-Splitting-Method Hybrid Scheme: A Simple Transient-Flow Model for Managed-Pressure-Drilling and Underbalanced-Drilling Applications

Abstract

Summary Transient flow models play an important role in the planning and follow-up of advanced well operations such as managed pressure drilling (MPD) and underbalanced operations. The most recent trend is a situation whereby flow models and control-engineering algorithms are combined in various settings to control flow parameters. This requires robust flow models and an in-depth understanding of uncertainties in the modeling process. This paper presents a simple and robust transient model that can handle highly dynamic flow systems. The model, the Advection-Upstream-Splitting-Model hybrid scheme, was developed for academic and training purposes. With the model, students can investigate different flow scenarios and pressure-control challenges encountered in general well control, MPD, underbalanced drilling, and automation. The capability of this model to handle highly changing flow scenarios is demonstrated with examples taken from MPD and underbalanced operations. The effect of numerical dissipation on the model predictions is briefly discussed.