As a matter of fact, both Venezuela and Bolivia have threatened to relinquish their membership in the ICSID. What's that say for the settlements?

Not much. Apparently you have not done any arbitration and are also unfamiliar with the bilateral investment treaty, which is linked in the link library for members to review.

The settlements made are binding under international law and must be enforced by member nations. Doesn't matter it VN withdraws, every other member nation will still enforce the settlement or judgment, and as long as VN sells oil anywhere in the real world they will have assets available for judgments.

As far as VN withdrawing from ICSID, it is covered by Article 17, § 2 of the BIT:

"In respect of investments or commitments to invest made prior to the date when the termination of this Agreement becomes effective, the provisions of Articles I to XVI inclusive of, and the Annex to, this Agreement shall remain in force for a period of fifteen years." (i.e. Hugo will be dead before the treaty is null)

While my great preference is to get a good deal or a permit, arbitration is a stremlined process that generally takes 2-3 years to achieve a final decision (non-appealable). Our only real impediment is not Hugo, that is a slam dunk, the real issue is keeping the bondholders at bay until the process is complete. That is the challenge for Mr. Fung if no permit is forthcoming.

Court litigation by contrast can take a decade or more and costs a factor of ten or more to do, which gives rise to the urban myth that all legal proceeding take forever.