Oracle get sql redo from log_history
First of all export is not backup. You will not recover a physical copy of a database from exp-dump, only an unconsistent copy of its data (you can make them consistent but the option is rarely used). I'm really not sure you can apply the contents of logMiner on such a copy.

Your best bet would be to apply undo statements to your current copy of the DB to return it to its original state, such as described in the documentation:


  If you fully understand and take into account existing dependencies, it may be possible to perform a table-specific undo operation to return the table to its original state. This is achieved by applying table-specific reconstructed SQL statements that LogMiner provides in the reverse order from which they were originally issued. See Scenario 1: Using LogMiner to Track Changes Made by a Specific User for an example.


Unfortunately it would seem that your customer is running its DB in NOARCHIVELOG mode since the view V$ARCHIVED_LOG is empty. V$LOG_HISTORY only records the switchs of the online redo logs which all DBs have. Only databases that are setup in ARCHIVELOG mode will archive redo logs.

I'm afraid your customer is out of luck.

At this point you should probably consider contacting Oracle support.