Sorry, no idea what a senior process engineer might make in Doha but it should be more than you are making in Canada plus housing, transportation, insurance and, if you have kids, definitely full education expenses. You are usually given housing but if not you will need 12-20,000 QR/mo for housing for you and your family. Usually you are given a one-time furniture buying allowance and/or shipping costs for a certain weight.
Mandi