Looking for Curran Somerville

Is there anyone who can tell me what the historical connection between the Currans and Somervilles might be?  I have a GG Grandmother, Sarah Eliza Somerville O'Connor, who lists her father as Curran Somerville. The only Curran Somerville I have found was born in Virginia - not in Ireland as was Sarah.   My Curran Somerville was a shipping clerk in (I believe) Belfast, Ireland.  Any and all info or suggestions will be greatly appreciated!