Model ID: 459
This model defines transient flow to a well of finite radius in a confined aquifer. The results from this analysis are compared to the well known Theis solution for flow to a point well. What distinguishes this model from the Theis problem is the well geometry.
Since the analytic solution describes the well as a point source which produces unphysical results inside the wellbore. The COMSOL Multiphysics analysis produces a physically based solution in the well using extrusion coupling variables to extend the results at the well edge over the well interior.
Apart from the well geometry, assumptions underlying the Theis problem apply. The reservoir is of infinite horizontal extent and is confined above and below by impermeable layers. As the well fully penetrates the reservoir, withdrawals are uniform along its length, making flow entirely horizontal. Storage in the well is neglected. Fluids are released instantaneously from storage in the aquifer. Prior to pumping, the flow field is at steady state. Flow is horizontal, does not vary with depth, and equipotentials are axisymmetric about the wellhead.