Blair's alternative source of oil (6)
I believe the answer is:
orwell
'blair's' is the definition.
(I've seen this before)
'alternative source of oil' is the wordplay.
I cannot really see how this works, but
'alternative' could be 'or' and 'or' is found in the answer.
'source' could be 'well' (well is a kind of source) and 'well' is found within the answer.
No letters remain.
This may be the basis of the clue (or it may be nonsense).
Can you help me to learn more?
(Other definitions for orwell that I've seen before include "Writer of 1984" , "George --, British author" , "George -, nineteen eighty four author" , "River" , "banker" .)