Making products from oil — some pretty rich, possibly (14)
I believe the answer is:
petrochemistry
'making products from oil' is the definition.
I can't judge whether this definition defines the answer.
'some pretty rich possibly' is the wordplay.
'possibly' indicates anagramming the letters.
'some'+'pretty'+'rich'='someprettyrich'
'someprettyrich' with letters rearranged gives 'PETROCHEMISTRY'.
Can you help me to learn more?
(Other definitions for petrochemistry that I've seen before include "Study of the rocky" , "testing for oils" .)