Corrupt oil rig mob in a dilemma (9)
I believe the answer is:
imbroglio
'a dilemma' is the definition.
(I've seen this before)
'corrupt oil rig mob' is the wordplay.
'corrupt' is an anagram indicator (a corrupted spelling of the word).
'oil rig' becomes 'oilrig' (synonyms).
'oilrig'+'mob'='oilrigmob'
'oilrigmob' with letters rearranged gives 'IMBROGLIO'.
'in' acts as a link.
(Other definitions for imbroglio that I've seen before include "Intricate and confusing heap or situation" , "Confused mess" , "Confusion" , "quandary" , "Dilemma" .)