It is impossible to tell the whole oil story, but perhaps I can offer a few insights regarding where we are today.
 We already seem to be back to the falling oil prices and refilling storage tanks scenario.
US crude oil stocks hit their low point on January 19, 2018 and have started to rise again. The amount of crude oil fill has averaged about 365,000 barrels per day since then. At the same time, prices of both Brent and WTI oil have fallen from their high points.
Figure 1. Average weekly spot Brent oil prices from EIA website, with circle pointing to recent downtick in prices.
Many people believe that the oil problem, when it hits, will be running out of oil. People with such a belief interpret a glut of oil to mean that we are still very far from any limit.
 An alternative story to running out of oil is that the economy is a self-organized system, operating under the laws of physics. With this story, too little demand for oil is as likely an outcome as a shortage of oil.
The Peak Oil story got some things right. Back in 1998, Colin Campbell and Jean Laherrère wrote an article published in Scientific American called, “The End of Cheap Oil.” In it they said:
Our analysis of the discovery and production of oil fields around the world suggests that within the next decade, the supply of conventional oil will be unable to keep up with demand.
There is no single definition for conventional oil. According to one view, conventional oil is oil that can be extracted by conventional methods. Another holds it to be oil that can be extracted inexpensively. Other authors list specific types of oil that require specialized techniques, such as very heavy oil and oil from shale formations, that are considered unconventional.
Figure 1 shows the growth in unconventional oil supply for three parts of the world:
Figure 1. Approximate unconventional oil production in the United States, Canada, and China. US amounts estimated from EIA data; Canadian amounts from CAPP. Oil prices are yearly average Brent oil prices in $2015, from BP 2016 Statistical Review of World Energy.
Oil prices in 1998, which is when the above quote was written, were very low, averaging $12.72 per barrel in money of the day–equivalent to $18.49 per barrel in 2015 dollars. From the view of the authors, even today’s oil prices in the low $40s per barrel would be quite high. Since the above chart shows only yearly average prices, it doesn’t really show how high prices rose in 2008, or how low they fell that same year. But even when oil prices fell very low in December 2008, they remained well above $18.49 per barrel.
Clearly, if oil prices briefly exceeded six times 1998 prices in 2008, and remained in the range of six times 1998 prices in the 2011 to 2013 period, companies had an incentive to use techniques that were much higher-cost than those used in the 1998 time-period. If we subtract from total crude oil production only the production of the three types of unconventional oil shown in Figure 1, we find that a bumpy plateau of conventional oil started in 2005. In fact, conventional oil production in 2005 is slightly higher than the later values.
Figure 2. World conventional crude oil production, if our definition of unconventional is defined as in Figure 1.
For a long time, there has been a belief that the decline in oil supply will come by way of high oil prices. Demand will exceed supply. It seems to me that this view is backward–the decline in supply will come through low oil prices.
The oil glut we are experiencing now reflects a worldwide affordability crisis. Because of a lack of affordability, demand is depressed. This lack of demand keeps prices low–below the cost of production for many producers. If the affordability issue cannot be fixed, it threatens to bring down the system by discouraging investment in oil production.