Thank you for your posting.
First of all, try to excel on your GMAT. Although you did well in your masters, the higher your score the easier your life will be.
Next, people from the oil and gas/energy sectors are very well received in the business school admissions process. Also, be sure to have compelling reasons as to why you want to transition positions/focus within this industry - you have to make a compelling case on this. This is true for anybody who wants to stay in the same industry.
As your undergraduate grades have used up all of your margin of error in this process, make sure that your applications (essays, recommendations, resume, interview, etc) are all top quality. Even a mediocre application will damage your chances much more than you can ever realize.
Lastly, I would apply to as many schools R1 as possible. I know that this may be difficult given time constraints, but I highly recommend it.
Senior Admissions Consultant Manhattan Review
Manhattan Review GMAT Prep & MBA Admissions Consulting
Web: http://www.manhattanreview.com | Phone: +1.212.316.2000
Receive 20% off Admissions Consultings as GMATClub member!