In US federal lands and waters, a licensee has commercial rights to any oil and gas production for the period of his lease (and conditioned on his fulfilling performance requirements, like paying royalties to federal and state governments). It would be a stretch to call the set of commercial rights and obligations “ownership,” a word we use in reference to homes and cars.
The oil company needs to be able to report discounted future revenue from his discovered proved reserves in order to balance future revenue against the amount of investments to date. The “ceiling test” is a key indicator for investors, who would like to see estimates of $2 of discounted future revenue for every $1 deployed in current investments.
These proved reserves may be either “producing” or “non-producing.” At present, Mexican rules prohibit even a statistical relationship by a contractor to oil in situ, be it from producing or non-producing reservoirs.
This is the circle that the energy reform must square.