Preserving Jobs in the Oilfield Act of 2013 - Directs the Secretary of Transportation (DOT) to ensure that, with respect to maximum hours of service for drivers, on-duty time does not include waiting time at a natural gas or oil well site for operators of commercial motor vehicles transporting supplies, equipment, or materials (including produced fluids, drilling and completion fluids, and any other fluids or materials used in the drilling, completion, and production of an oil or gas well) to or from a natural gas or oil well site.

Applies this exclusion regardless of whether operators have received special training or operate vehicles specially constructed to service wells.