Is it reasonable for me to pursue MSc petroleum engineering? What is the projected job prospect for 2012?

Hi, I'm a mechanical engineering graduate and a nigerian with 5 years experince (come October 2011) in maintenance management-maintenance planning, failure analysis, preventive maintenance, condition-based maintenance- and the project management using SAP ERP based computerised maintenance and project management system (SAP MM, PM and PS Modules). Now, I want to pursue my long term degree of becoming a petroleum engineer and I already have an offer from Heriot Watt for MSc Petroleum Eng.. I will be 32 by the time i graduate if I enroll. I would like to know from experienced oil and gas professionals if I would have a good chance of getting a good job in the industry and if my experience would count (since it was not gained strictly in the O &G industry)? This is a big decision for me. Definitely I love pet eng. but would like to know what to expect and whether it is a sensible decision to take. I also have an offer from leeds for Msc oilfield corrosion engineering and MSc advanced mechanical engineering which I think are more closely related to my experience and background, however I prefer petroleum engineering career but would not mind if these other options are better for me.Also which gives a better prospect in terms of pay and career development? Expecting your kind guidance and advice