Qatar is getting friendlier and there are more avenues to spend every day.You can save around 12K for sure. If you are targetting 15K savings(which is ambitious), Deduct 2-3K for the Comfort/fun factor. Since you wont have a great social life Why not spend a bit on weekends,dinings,outings and splurging?? After all you would want to save with fun.

If you really want to save 15K, Find a housing not more than 8-9K . That will save you 15K.