Shell Rival is a term used to describe the three major oil companies that compete with Shell Oil Company. These companies are Hess Corporation, ExxonMobil Corporation, and Mobil Corporation. Hess Corporation is a global integrated energy company based in New York City. ExxonMobil Corporation is an American multinational oil and gas corporation headquartered in Irving, Texas. Mobil Corporation is a subsidiary of ExxonMobil Corporation and is also based in Irving, Texas. All three companies are major competitors of Shell Oil Company.