Hello Jharna,
Since you do not have any other ETL like Data Services.
If you have BW 7.4 OR BW 7.3 with HANA only then you can configure the Oracle DB connection in the T-code DBCON and then choose the Open Hub setting to write to a "Database table".
If you are in a BW version which is less than the above ones that I specified, then I am afraid there is no option available till your system is upgraded.
Thanks,
Sundeep