Methods and Software for Interpolating/Modelling of Stratigraphic Well Data in 2D/3D
OpendTect may do this, however getting to that stage would be a painful experience. 

Petrel can do this very easily, however, that is not anywhere near free...

If you're a student, your department may have access to a few decent programs to achieve this. If you could find out what you have available, we might be of more help!