Joy at Texan oil production (10)
I believe the answer is:
exaltation
'joy' is the definition.
(thesaurus)
'at texan oil production' is the wordplay.
'production' is an anagram indicator.
'at'+'texan'+'oil'='attexanoil'
'attexanoil' is an anagram of 'EXALTATION'.
(Other definitions for exaltation that I've seen before include "Larks" , "Extreme happiness" , "delight" .)