Sonatrach is the national state-owned oil company of Algeria. Founded in 1963, it is known today to be the largest company in Africa with 154 subsidiaries, and often referred as the first African oil "major". It is the largest oil and gas company in Africa by revenue, with $US 39 billion in 2018.
Sonatrach is the 12th largest oil consortium in the world, with 154 subsidiaries operating over the entire oil value-chain from upstream, to midstream, and downstream activities.
Sonatrach operates the largest oil field in Algeria, Hassi Messaoud, which produced around 440,000 bbl/d (70,000 m3/d) of crude in 2006. Sonatrach also operates the Hassi R'Mel field (north of Hassi Messaoud, south of Algiers), which produces around 180,000 bbl/d (29,000 m3/d) of crude.
Other major fields operated by Sonatrach include Tin Fouye Tabankort Ordo, Zarzaitine, Haoud Berkaoui/Ben Kahla, and Ait Kheir.
According to en.wikipedia