What buildings already have animation? Can you work backwards from there?
I've found a lot of interesting tidbits in the LPlot (sp?) XML files for terrain and city layout. (For example, that's where the many states of wineries -- unimproved/unworked, unimproved/worked, improved/unworked, improved/worked). I suggest start by looking there.
What happens if you put a structure that you KNOW is animated (e.g., the oil well) in as a city building?