You don't mention Oracle Version or OS and version, but I guess it doesn't matter in this case.
Do you have any tools at your disposal. I would use TOAD to make quick work of this problem.
Otherwise, you could write a query against the DBA_SYNONYMS view in the test database to generate the create synonym commands you need, spool the ouput to a text file and then run this against the production database.
Something along the lines of:
SELECT 'CREATE SYNONYM '||synonym_name||' for '||table_owner||'.'||table_name||';'
WHERE owner = 'user1';