Years ago — well, it was the ’80s — we received a call from a West Coast customer who was having thread problems on his new Driltech rig. After a couple of months, some of his threads were becoming damaged to the point that they would no longer shoulder, and some were really difficult to break. I made arrangements to meet the local Driltech rep at the Sacramento airport.
Meanwhile, all the possibilities were running through my head. Was this a case where we made a bunch of bad threads? Or, maybe we made one bad thread whose damage was migrating through the entire drill string? Maybe the threads were good, but we damaged them during the welding, cleaning and painting process. Maybe the operator damaged the threads. Maybe they were using generic grease instead of a good grade of tool joint compound. What if I cannot find the cause?