Casing while drilling (CWD) has been around in the rotary business for only 20 to 30 years, but cable tool drillers have been using this method since about day one. In overburden and soft formations, drill and drive has been the standard method forever. When the driller reaches a competent or hard rock formation, he can seat the casing in the rock and continue without worrying about losing his hole.
In rotary drilling, there are several different reasons for CWD. Unstable formations, flowing sand and high pressure are good reasons to consider this method. The first method is to attach the bit permanently to the drill pipe. This is probably the cheapest and simplest method. You drill with the casing, and when you have reached total depth, you perforate the casing where you want production. It doesn’t require a special casing shoe. The downside is that you can’t drill below the casing without milling up the bit. No fun.