Improving oil prices over the past few months are fueling many investors and analysts to ask at what oil price drillers will start adding back rigs. That was the very first question an analystasked ConocoPhillips' management team on its last quarterly conference call. However, instead of pointing to a particular oil price as some of his counterparts did, Al Hirshberg, ConocoPhillips' executive vice president of production, drilling, and projects, had this to say: