There are sections on this site for Surveyors but it is not used.
Norwegian tax rules are dependant on which country you are a vitizen of, I have no idea of the tax agreement between Australia and Norway.
Norwegian companies are one of the best to work for, they really do treat people well and working conditions tend to be the best. The tax is not something they can deal with, basically see if you can find out how much you will end up with in your pocket to work out whether its worth your while. I also thought Ozzies had to pay Ozzie tax no matter where in the world they live?
Fugro Survey in Aberdeen seem to be trying to take over the Survey worls, they have offices all over, might be woth speaking to them?