Steps in the following metalink documents should be followed to do the database upgrade from 11.1.0.7 to 11.2.0.4.
Interoperability Notes EBS 12.0 and 12.1 with Database 11gR2 (Doc ID 1058763.1)
Complete Checklist to Upgrade the Database to 11gR2 using DBUA (Doc ID 870814.1)