A system is provided for injecting coiled tubing (CT) into and out of a wellbore. In embodiments, separate injector and reel units are provided releasing constraints on CT size and length. The injector unit is fit with an extendible mast for handling larger bottom hole assemblies and fit with a rotating gooseneck for accepting CT from alternate arrangements of the reel unit. The mast is reinforced to resist CT loading. The capacity of the reel is maximized for the reel unit transport envelope. The reel is rotated using an offset drive engaging a bounding reel flange, such as engaging drive and bull gears. A generally radial displacement of the drive from the reel permits replacement of the entire reel.