All four of BHP's US shale datarooms are now open and the global Australian says it is likely to attract up to 50 authentic investors to the sale process for the two oil-rich corners of its portfolio.

BHP petroleum president Steve Pastor confirmed on Wednesday that "two dozen" potential bidders had executed the necessary confidentiality commitments that opened the door to diligence on the place where BHP's shale failed experiment in shale started – the dry gas shales of Fayetteville in Arkansas.