Any degree'd engineer in the oil field with a strong work ethic will make more than enough money to pay back any student loans that you may stack up. There is a lot of money to be made in the oilfield if you are willing to do the work.
I have been working for a "major" service company for only two years and will top 6 figures. It is not MD type money but more than I ever imagined I would make when I was in college. I will be stepping away from that career field in the near future to pursue something else but it is not a "not enough" money issue.
Things can always change in the industry, but from everything I have seen we will remain busy for the foreseeable future.