Dear Nabil,
Please perform Export-import using sapinst from PRD to test system, bcoz Exp-imp is independent of OS & DB Platform:-
1) First take Export of PRD (assuming, in PRD you have oracle10g).
2) Then , while importing, System ask which DB,kernel you want to import on. At this moment, browse path for oracle11g, new kernel. So , by this your test system will get PRD data and DB upgrade to 11g.