First line supervisor whose main duties are to control the activities of his crew and to train those crew members in the proper way to perform their assigned tasks. The driller is responsible for operation of the drilling and hoisting equipment. This person is also referred to as the “crew chief” or “rig operator” in well servicing operations.
Source: API RP 54, Recommended Practice for Occupational Safety for Oil and Gas Well Drilling and Servicing Operations, Third Edition, August 1999 (2007). Global Standards