Galp

ExxonMobil is a parent company to ExxonMobil Exploration Company, ExxonMobil Development Company, ExxonMobil Production Company, and many other companies.

KazMunaiGas Exploration Production - AO - was created in 2004.

Continental Resources is an American petroleum and natural gas exploration and production company. They primarily focus on the exploration and production of oil and natural gas reserves in North Dakota and Oklahoma, with a particular emphasis on unconventional resources such as shale formations.