Model ID: 472
Analysis of fluid flow into wells often begins with the assumption that the intake fluid is uniform along the entire length of wellbore. This assumption runs into trouble when applied to the modeling of perforated wells. When these wells are emplaced, the deep bore hole is lined by impermeable materials. Later a machine pierces the lining intake fluids in the productive reservoir zones and nowhere else. The perforations are relatively small, typically less than 0.5 m long and with a diameter of less than 5. They typically are oriented at regular intervals cycling down the casing axis.
The ability to describe how fluids funnel into tiny perforations oriented about a well bore is the subject of a rapidly growing number of analyses. In that the perforations are isolated piercings as opposed to rings, the flow field is not suited for axisymmetric analyses - fully 3-D simulations are required.
This example demonstrates several useful COMSOL Multiphysics features. Included are instructions for using Lagrange multipliers to calculate a high accuracy flux on a relatively low density mesh. The model also shows how to set up boundary integration coupling variables to automate the flux calculations.