Oil Companies

The oil companies or agencies involved in the oil industry can be broadly classified into 3 groups:

1. Host Authorities
2. Operating Company or Operators
3. Service Providers

The "Host Authorities" are the ministries or the government agencies that officially administer the hydrocarbon asset of a state or country. They assign "Operating Company" to operate an asset and then monitor and authorize their activities. e.g. Directorate General of Hydrocarbon (DGH, India), ADNOC (Abu Dhabi), PETRONAS MPM (Malaysia) etc.

The "Operating Company" or "Operators" are the companies that the host authorities allow to explore and extract a hydrocarbon asset. They may refine and then distribute the produced hydrocarbon OR sale it to other companies that refine and distribute them. e.g. BP, ExxonMobil, Shell, Chevron, Hess, ONGCL, OIL, ADCO, ADMA, ZADCO, PETRONAS, PETROBRAS, PEMEX etc. A longer list can be found here.

The "Service Providers" provide a wide range of services to the "Operating Companies". e.g. Schlumberger, Halliburton, Weatherford, Baker Hughes etc.