drilling platform vs offshore rig

drilling platform and offshore rig both are nouns.

Word	Noun	Adjective	Verb	Adverb
drilling platform	Yes	No	No	No
offshore rig	Yes	No	No	No

As nouns, drilling platform and offshore rig are synonyms defined as:

drilling platform and offshore rig: drilling rig consisting of an offshore platform (floating or fixed to the sea bed) from which many oil wells can be bored radially

drilling platform (noun)	offshore rig (noun)
drilling rig consisting of an offshore platform (floating or fixed to the sea bed) from which many oil wells can be bored radially	drilling rig consisting of an offshore platform (floating or fixed to the sea bed) from which many oil wells can be bored radially