ABSTRACT
Casing and cementing have been put together because they go together. The threading of casing is much preferred as "bonding", grommets or grub screws can prove somewhat unreliable at depth. The storage of plastic casing is important because, badly done, it will "bow" and "twist" and will therefore be difficult to run down a hole in spite of its flexibility. Wrap-around tongs are always best to use for tightening casing, especially plastics, although a good set of chain tongs have been used for a century or more and cannot be ignored when using steel casing. Casing hangers are used for placing casing strings inside a hole—that is, not terminating at ground level. The "tremie" in this case can be drill-pipe provided we are using internal flush drill-pipe. Tresmie is a long rigid pipe or pipes screwed together which is connected to the cementing pump by a hose, through which cement can be pumped.
