The oil-field services sector is in the tough position of being the first to get hurt when oil prices plunge and the last to profit when a recovery finally happens. That lag has always existed, but this time it seems like an endless nightmare for oil services companies, both small and large.

The most obvious evidence is the recent announcement by Weatherford International of its plan to file for Chapter 11 bankruptcy protection. Weatherford, the sector’s fourth largest player, is a genuinely diversified global outfit with a hand in just about every significant business sector across the oil and gas industry.

To be sure, Weatherford’s extraordinary debt load of $7.7 billion was somewhat unique, but the forces depressing its finances were not. Share prices for bigger, stronger rivals like Schlum