This article provides two pieces of information for upgrade of soa suite.
The recommendation for free table space space for upgrade is atleast 25% free space for soa.
The recommendation for free temp space for upgrade is atleast 800MB free temp space for soa.
If you want to upgrade a large number of jdeveloper projects in bulk without opening them one by one in jdeveloper, use jdeveloper tool ojmigrate installed in the 12c oracle home.
ojmigrate [option]... file...|@file
file Workspace to migrate.
@file File with workspaces to migrate (one filename per line)
-ade Connect to currnt ade view
-dry Dry run. Skips calling migrators
-failFast Stop migrating after first failure
-generateDefaults Don't migrate let. Let migrator helpers to generate
files containing dafults for migration options.
It will usually be migration.prperties file
alongside the .jws file.
For more information on upgrade best practices, look here.