perhaps relevant here?

http://www.ft.com/intl/cms/s/0/3568c456-2a6c-11e1-9bdb-00144feabdc0.html#axzz1jEWGXeIK

You need to register to view the above FT article, but it is free (and well worth while!)

...“To join an exploration well is a few million dollars – but if you have success, you may be left with a development bill which could be hundreds of millions of dollars,” Mr Rose said.

Financing constraints for companies that are part of successful exploration ventures is making them “vulnerable to low-ball bids” from better-positioned operators, he added. “It’s just more difficult for single-asset exploration companies to get finance than it was a few years ago.”...