Cooperation as in oil production (7)
I believe the answer is:
liaison
'cooperation' is the definition.
(I've seen this before)
'as in oil production' is the wordplay.
'production' indicates an anagram.
'as'+'in'+'oil'='asinoil'
'asinoil' is an anagram of 'LIAISON'.
(Other definitions for liaison that I've seen before include "Intermediary" , "Intimate relationship" , "An affair or mediation" , "Naughty affair?" , "A contact or affair" .)