In the oil and gas industry, counting is everywhere—active rigs, barrels produced, dollars earned (or lost) and, of course, wells drilled.
Counting wells is a fairly straightforward exercise until you reach the drilled but uncompleted, or DUC, phase.
DUCs are counted for several reasons, the most prominent of which is to gauge size and timing of the domestic supply response to changes in oil prices, with or without significant changes in the number of active drilling rigs. The more DUCs there are, the faster reaction time the industry can have to increase production. Fewer DUCs mean less opportunities for swift supply additions.