Kaskelot: One more thought, if a trust currently owns the minerals. Have the attorney review it to see if the trustee can receive the payments for your share of the royalties, then distribute your income to you.
Also, it is possible that a treaty between your country and the USA could contain property ownership provisions which may override the Oklahoma statute.
This post is not legal, tax or investment advice. Reading or responding to this post does not create an attorney/client relationship.