With RET you can calculate rate or flowing pressure in the three types of flow regimes:

-Steady-state flow
-Pseudosteady-state flow
-Unsteady-state flow

Also you can do examples of reservoir simulation considering the follow features:

-One dimension
-One phase (oil)
-Incompressible or Slightly compressible fluid
-Rock porosity constant or depending of pressure
-5 different types of boundary conditions
-One well (specified production rate or specified flowing pressure)

You could check your result of your calculation by hand or your own code
Check it and tell us wath you think
Enjoy it