Oil exploration companies include Anadarko Petroleum Corporation, Apache Corporation, Chevron Corporation, ConocoPhillips, Continental Resources, Devon Energy, ExxonMobil, and Greka Energy. For a more exhaustive list, see the Wikipedia article "List of oil exploration and production companies."

Suncor Energy, Imperial Oil, and others, many of which are listed in this linked page.

Lots of companies drill for petroleum, It's one of the biggest industries in the world.

Cell phones are not allowed in petroleum companies because the cellphone signals can easily cause fire and result in devastation. 

They r engineered by oil companies