Paul,
Interesting question! I know our workflows ae just being formalised as this is a relatively new problem. I believe the main problem lies in the fact that most static modeling (and dynamic) packages relly on GRV (contacts & structure) and some rock properties (N/G,
POR, Sat, recovery factor related mostly to permeability) to estimate the recoverable reserves for hydrocarbons. For unconventionals contacts are no longer important, GRV can be irrelevant (very extensive 'reservoirs'), porosity is off the scale and permeability relies on what one does to the wells (fracking). Packages will need to be able to model large extensive fields while maintaining resolution around the well. Apart from that temperature starts playing an important role. I have also not seen a good 3D modeling suite that can incorporate all this and also allows one to model fractures accurately.
In the end I believe volumes and reserves for unconventionals cannot be estimated using static models, but require complex dynamic models. Often flow is fast at first, but may decline very fast as one basically is working with two permeabilities: one for the fractures and one for the shales itself.
To answer your question... I can not suggest a tool (I know off) that handles shale gas reservoirs in such a way that is currently used/proven for conventionals.