What will the price of oil be?

Analysts disagree over whether the price of oil is going to increase substantially or remain at its current low value (WSJ, July 2020). Some of the analysts argue that low prices are depressing investment so much that prices will increase in the future. Others argue that the demand will remain low. Let's use economics to investigate. Remember that a decrease in investment is equivalent to exit and an increase in investment is equivalent to entry.

1. How does a decrease in demand affect the price of oil in the short run?
2.  How does a decrease in investment affect the price of oil in the long run?
3. If the industry is competitive and the minimum average total cost is $60, is $150 a sustainable price?
4. If the industry is competitive and the minimum average total cost is $60, is $40 a sustainable price?
5. If the industry is competitive and price in the short run falls below the minimum average total cost, what happens to price in the long run?
6. If the industry is competitive and price in the short run rises above the minimum average total cost, what happens to price in the long run?