oil industry vs refining industry

oil industry and refining industry both are nouns.

Word	Noun	Adjective	Verb	Adverb
oil industry	Yes	No	No	No
refining industry	Yes	No	No	No

As nouns, oil industry and refining industry are synonyms defined as:

oil industry and refining industry: an industry that produces and delivers oil and oil products

Other synonyms of oil industry include oil business.

oil industry (noun)	refining industry (noun)
an industry that produces and delivers oil and oil products	an industry that produces and delivers oil and oil products