Help with 2D simulation of carbon dioxide migration through a porous medium
 

I am trying to perform a simulation of carbon dioxide migration through a hypothetical sandstone section. This is for an investigation into Carbon Capture and Storage, where CO2 is injected into rock underground. At the moment I am trying to perform a single phase, 2D simulation (rectangle) using an axisymmetric geometry.

My problem lies in defining the axis about which the problem is symmetric.
I want to define the vertical line on the y-axis as being the axis of symmetry (i.e. centre of a well), but I then also want to define a parallel line lying 0.5m away from this axis as being the velocity inlet. How would I do that?

I am completely new to ANSYS Fluent and any help would be greatly appreciated. If anyone needs further information to help solve my problem, please ask. Thanks.