The question of claiming unclaimed property is very difficult, and it is central to any theory of property rights. I am fully aware of the need to systematize it, and in fact was preparing a theoretical article on this, that after 9/11 needed major reworking. We'll return to that if you keep yourself from getting banned :)))
Here is a short outline. Oil under someone else's desert is unclaimed property. The property right to oil go to the one with technology to extract it. The only way to argue otherwise is to say that the government claims the property just by the virtue of a national border, a dubious proposition.
Balogney. I own the mineral and water rights to my property and I have no technological ability to drill for oil. Nobody may enter my property and drill for oil simply because they own the technology. That would be theft. What you and Piekoff are advocating is a justification for theft which has no basis in property rights but an imagined absence of property rights.
Wait a minute. Oil under someone's desert belongs to the person who owns the desert.
What you just said would mean that if there's oil under my house, the first person who has the ability to drill can claim it, and he now owns the oil. Owning oil implies the right to drill it, which would mean having a right to set up an oil rig on my land without my permission and perhaps even a right to demolish my house to make room for it. Surely you can't mean that.