Computational Fluid Dynamics (CFD) has been used to model fluid behaviour in reservoirs, near wellbores and wells. More recently the CFD has been applied to more diverse challenges such as sand transport, coupled mechanical modelling of failing wellbores and gas well clean-up. CFD has been applied to model the crushed zone around perforation tunnels and also to predict well performance base on laboratory testing. Where the reservoir is involved in these models they are fully coupled and flow is enabled deep in the reservoir and in to every point along the well.
Capturing the simultaneous flow of fluids in the reservoir and in the well is essential to predict performance in wells and reservoirs with complex geometry. Cross flow between reservoir layers and the flow of fluids through and along the well length are real phenomena which if ignored, can lead to poor prediction of well performance. CFD modelling relies on fundamental physical properties and enables changes in flow restriction such as formation damage or matrix stimulation to be captured. This paper presents some recent case histories where model results are verified by real well performance and where traditional analytical model results are compared to fully coupled CFD reservoir and well models. The impact of formation damage is observed to produce very different results, depending on the model applied.
Case histories illustrating the application of innovative, rigorous modelling of formation damage from different drilling and completion fluids and practices are presented. Further advances that enable sand failure and sand transport to be modelled are also illustrated. The case is made for use of CFD or similar modelling processes where complex reservoirs or complex wells are considered.