This is the 13759th most frequent Russian word.
нефтекомпании
Oil companies.
In this sentence, 'нефтекомпании' is used as a plural noun referring to oil companies in general, emphasizing their economic significance.
Нефтекомпании играют важную роль в экономике России.
Oil companies play an important role in Russia's economy.
Here, 'нефтекомпания' is used as a singular noun, referring to a specific oil company that achieved the discovery.
Эта нефтекомпания недавно открыла новое месторождение.
This oil company recently discovered a new oil field.
In this context, 'нефтекомпании' refers to a group of international oil companies collectively engaged in market competition.