I can remember when my dad was working for George E. Failing Company as a salesman and troubleshooter. He usually hung out at Failing Plant No. 2 in South Enid, Okla., where the original Failing drill sat outside for many years. That rig was my playground.
The distinguishing feature of the dual-rotary (DR) drill rig is a lower rotary drive, which is used to independently advance casing up to 40 inches, depending on the drill model.
In normal mud rotary drilling, it is not unusual for solids content to approach 20 percent of returns during fast-hole drilling. This is good; it means fast penetration and thus, a quicker, more profitable hole. The trick is to get the solids out of the mud before it is returned to the hole.
