Please consider closing some of you old questions.
0. Disable log shipping from the Primary 1. Shutdown Standby 2. Install patch on Standby software only 3. Startup Standby in recovery mode (do NOT run any SQL at the standby) 4. Shutdown Primary 5. Install patch on Primary 6. Run SQL on Primary 7. Re-enable log shipping 8. Monitor the redo apply from Primary to Standby --- this will also upgrade the Standby See Oracle support article : How do you apply a Patchset,PSU or CPU in a Data Guard Physical Standby configuration [ID 278641.1]