How to patch long strip on drywall?
Sounds like you tore off some of the paper on the face of the drywall. This is cosmetic damage and if it wasn't over a seam it doesn't need tape. Scrape the glue (go ahead and damage the wall a little), apply spackle, sand it, (repeat?), paint.

Anywhere with crumpled up paper sticking-out (will not sand flat) needs to be bashed in (using the corner on the butt of a small trowel) and filled; circles with a wet sponge never worked for me. Which is the trick for dealing with the fuzzies where the paper has delaminated and you're looking at a brown spot. Attempt to sponge these types of areas and then apply a skim coat of plaster or it will show in the finish paint. Use a damp sponge, DO NOT saturate the wall, or the entire section may bubble.

An 8-12" trowel makes doing large patches much easier, try not to leave too much at the edges where it meets the old work (this is the most important area to bevel sand). While sanding it, you should begin to feel a nice feather once the old paint starts showing through in spots. 



This is kind you want, not a flat trowel with an in-line handle. Those require a bit more experience to use and you still need one of these. If you do buy both, a good tip is to bend the flat trowel a tiny bit, making it ever so slightly concave. This facilitates a nice build-up along the center and gives you an already good taper at the edges.