Multiphase CFD Analysis of a Subsea Intervention System

In this study, a computational fluid dynamics (CFD) analysis was conducted to evaluate a new design of an intervention system. A multiphase analysis was performed to understand the mixing characteristics as the cement is pumped into the well and the degree to which the cement could be contaminated with spacer fluid. A transient multiphase analysis was conducted to examine the flow and the mixing behavior through the various sections of the intervention system. A combination of 2D and 3D CFD models was used, depending upon the geometry in each section. The results indicated that the intervention system operates efficiently without diluting the cement. Non-Newtonian methods used in CFD were validated using available theoretical and experimental data. In a large-scale yard test, good agreement was obtained for resin and water; however, cement did not show good agreement as the flow rate increased over 1 bbl/min.