I would look at the ranking of top MBA's worldwide. A top ranking MBA in europe is almost always cheaper, in a lot of cases in English, and it will give you abroad experience as well. Which would definately help out in the oil industry.
As you mention the MBA doesn't directly help your carreer but you're doing this for the experience as well, that's just one extra reason to look elsewhere. And if you ever go to a different company where MBA's do matter more it's as simple as adding a line ' one of the top 10 MBa's worldwide' to your resume.
I can recommend Nyenrode in the Netherlands (it is the university I went to myself) it has scored #1 as the best MBA worldwide for your carreer. Admission fees are ' only' 32.500 for the entire MBA. There's on campus living and such and an active student live. And, not unimportantly, the entire program is in English.
That's even if you add living expenses, and travel a lot less than the 250.000 you're looking at now. The price is so 'cheap' because there's hardly any private education in the Netherlands. Normal universities cost 1.300 per year. So if you need to compete with that as a private university you need to keep your costs quite low as well. http://www.nyenrode.nl/Education/MBA/IM ... fault.aspx
Please contact me if you have any questions about Nyenrode.