wildcat well vs oil well

wildcat well and oil well both are nouns.

Word	Noun	Adjective	Verb	Adverb
wildcat well	Yes	No	No	No
oil well	Yes	No	No	No

As nouns, oil well is a hypernym of wildcat well; that is, oil well is a word with a broader meaning than wildcat well:

wildcat well: an exploratory oil well drilled in land not known to be an oil field
oil well: a well that yields or has yielded oil

Other hypernyms of wildcat well include oiler.

wildcat well (noun)	oil well (noun)
an exploratory oil well drilled in land not known to be an oil field	a well that yields or has yielded oil