When using asynchronous mode, the user connecting to the instance must be granted admin authorization on Oracle Streams. This is done using the DMBS_STREAMS_AUTH.GRANT_ADMIN_PRIVILEGE procedure when logged in with a user already having this privilege (for example the SYSTEM user).
When using the AUTO_CONFIGURATION option, the logged-in user must also have the DBA role to grant other users with privileges and change instance parameters.
The work schema must be granted the SELECT ANY TABLE privilege to be able to create views referring to tables stored in other schemas.
For detailed information on all other prerequisites, refer to the Oracle documentation (Data Warehousing Guide - Change Data Capture)
Knowledge Modules Reference Guide