 Based on horsepower, Calfrac is one of the largest hydraulic fracturing companies in the world.Calfrac Well Services Ltd. (CWS) was founded in June 1999 as a private corporation by Ronald P. Mathison, Douglas Ramsay, Gordon Dibb, and Robert (Robbie) Roberts.At that time, Calfrac had a single coiled tubing unit and was based in Medicine Hat, Alberta.