This is the answer I got from Oraclke support...
• This functionality is not currently available. An enhancement request has been logged with Development for this request:
• ER / Bug 3009987 <NEED A METHOD TO ARCHIVE AND THEN DELETE OLD STUDIES>
• This ER will be reviewed and considered by Development for a future release. It will remain open until it is either incorporated into the product, or it is deemed not feasible.