Expert drilling may get him strikingly rich (6)
I believe the answer is:
oilman
'expert drilling may get him strikingly rich' is the definition.
The answer is a person as well as being a singular noun. This is suggested by the definition.
'expert drilling may get him' is the wordplay.
'expert drilling may' becomes 'oil' (I can't explain this - if you can you should believe this answer much more).
'get' is a charade indicator (letters next to each other).
'him' becomes 'Man'.
'oil'+'man'='OILMAN'
Can you help me to learn more?
(Other definitions for oilman that I've seen before include "Worker" , "Owner of company that sinks wells for fuel" , "Person involved with crude" , "One working in the "black gold" industry" .)