Qatar govt. will not allow dual RP, you must cancel the UAE RP, otherwise you will not get residence permit in QATAR.

You may get entry visa while your UAE RP is valid but at the time of stamping Qatar RP in your passport they will return it to cancel.

As i'm working in petroleum company immigration section we have practiced the same issues many times. before two weeks there was a case with us. the employee's UAE RP was cancelled by writing on it with a pen, but the Qatar immig. returned it and asked to get cancel seal on it.

Note: around 8month, or more, i don't remember well, we sent a passport to immig. to stamp RP and the passport was holding a valid uae rp, but we get it back stamped with new Qatar RP, it means if they notice a valid UAE RP they will definitly return the passport to cancel it.

regards,

Akber