I was reading in my Alma Mater’s magazine about the fracking, and the guy said that yes there are hundreds of various chemicals used, but that it is primarily water, the propants (sp?) and a FEW chemicals that are designed to work in the environment of each specific well (I imagine things like temperature, pH, etc.).
Pretty much what your research has also shown.
Chemical Use In Hydraulic Fracturing
http://fracfocus.org/water-protection/drilling-usage