I think CanadianforQatar made a good decision by not accepting the offer.
My first year in Qatar was quite interesting as everything was new, but after that Qatar is very boring compared to home (and anywhere else in the world for that matter). Most Western expats I speak with that have been here more than a year count the days until their next vacation out of the Country. Therefore, it becomes the money as the only incentive to stay.
The other poster was also correct that QP is not a good choice for a career move. It is quite disfunctional and very bureaucratic compared to a Western company. QP currenlty has around 1800 vacncies and some departments are sitting with as much as 40% vacancy because of low offers so you can imagine how ineffective and frustrating it would be to work in that department.
If you want work in Qatar in O&G, I would choose all the Western Oil Companies first, then the JV's such as QatarGas and RasGas, then lastly QP.