This past October Lockheed Martin announced that it has found a way to build a nuclear fusion power plant. Physicists may be skeptical, but let's say this or some other technology develops sufficiently to supplant oil. There is no reason to think that that is impossible, for the Saudis are acting as though that may be the case. Of course, other explanations are possible for the Saudis' aggressive refusal to restrict production in the face of falling oil prices. For instance, the Saudis may want to retaliate against Iran or to help the US by putting Putin in his place. Also, they may want to blow high-cost producers like the North Dakota shale frackers out of the fracking well. If I knew the true reason, I would be in the oil market now, but I pulled out of all of my oil-related holdings, including midstream MLPS, which have not suffered so much yet.
If, however, the Saudis are, as Hinckley suggests, anticipating an end to the age of oil, and if they are now behaving as monopolist profit maximizers rather than holders of an appreciating asset, then their plan will be to equate the present value of the marginal costs of production from now until the anticipated end of the oil age to the present value of the marginal revenue. The marginal cost of the Saudi's oil production is much lower than the current price. According to a recent Business Insider article,
If the declining oil prices are a precursor to the invention of lower-cost energy sources, we may yet see curing of the harm that American voters and their politicians have done to the economy for the past 125 years.