Reposting as I found a bit on refineries in one of the URLs (editing had timed out).
Two webinars back, AP was indeed questioned about this (specifically Block 9). The question had been phrased as 'should US-Cuba normalise relationships, what is the risk for legal action on block 9' - or words to that effect. The implication being the Helms-Burton Act.
MAY's response was that they had investigated, and in-ground resources were always the sovereign property of Cuba and that they did not believe it would be an issue.
Attempts to sue using the Act, including one concerning oil infrastructure (see Exxon in immediate below URL), have not all worked favourably for the plaintiff:
The relevant Title III of the Act can also be, as has been on numerous occasions, suspended by the US President in the interest of US-Cuban relations.
Relations between the US and Cuba were beginning to normalise from 2015 when Obama visited Cuba; this was later undone by Trump's National Security Presidential Memorandum (2017-20-10).
Sherritt has/had a claim over its nickel / cobalt project for some $80+m (at one time exceeding its market cap). Also, because of the Act, Sherritt's CEO is unable to travel to the US (curious to know if this is the case for MAY senior management). Canada clearly considers the Act a crock.
(20min delay)