I have watched a lot of changes in the years I have been around the drilling industry, both in the water well business and the oilfield. When I was a kid, most of the well drilling was done with cable tool rigs. There were a few rotaries around, but we looked askance at those “new-fangled” rigs, wondering how they could possibly drill a good well in half a day, and do any quality work. They were obviously drilling so fast that they probably missed the water, just to make footage! The error of our ways was made obvious when economic reality set in. People no longer wanted to get on a six-month waiting list when they could have a well by tomorrow night. And even though those rigs were expensive, they paid for themselves many times over. Don’t get me wrong: There are still plenty of places that a cable tool rig is the right rig to use, but the choices are vast now.
Originally, almost all rotary rigs were table drive. Drillers got used to them, and they worked great. Still do. Now, almost all rigs are tophead drive. This gives great control and fast drilling, but takes some getting used to for a rotary-table driller.