sueco6 there are a large number of lounges at DOH but only four are of any use to QR/OW travelers.

Al Safwa is a First Class lounge for the exclusive use of QR First class passengers.
Al Mourjan is a lounge for the exclusive use of QR and OW Business and First class passengers only.
First class lounge is for the use of QR Platunum and OW Emerald members.
Business class lounge is for QR Gold and silver and OW Sapphire members.
There are also paid lounges.

Access to Al Safwa and Al Mourjan is strictly by cabin class. Rule of thumb: Cabin class as stated on the boarding pass for your departing flight.