Re: Its Oilfield Casing

More nits; that pipe is spiral weld line pipe not production casing. Casing has threads on both ends and with a "collar" or one or the other. The collar allows the joints to be "made up" or screwed together as they are run in the hole.
Spriral weld pipe is very difficult to cut threads on, in particular the round type of threads used on casing and production tubing. The heat created during the welding process hardens the metal in the area of the weld. This causes the cutting tools to chatter when they encounter the harder metal.
The other issue with using any type of welded pipe as casing is the seam can create problems with internal clearance for down hole tools such as isolation tools such as packers. This problems is reduced by running a "drift mandrel" or "rabbit" through the casing immediately before it is run. Casing that does not drift is set out for use as cattle guards and fence posts.
Spiral welded pipe is sometimes used to line rat holes and mouse holes when a drilling rig is over the hole.