nonassociated
adjective
non·as·so·ci·at·ed ˌnän-ə-ˈsō-shē-ˌā-təd 
-sē-
: not associated with someone or something else : unassociated
especially, of natural gas : not found in the same reservoir with petroleum deposits
When wells are drilled along this coast, they commonly encounter "nonassociated" gas—natural gas not associated with oil—under very high pressure. 
Barry Commoner
Barry Commoner 
Word History
First Known Use
1695, in the meaning defined above