Why did the international oil price fall?

The main reasons for the decline in international oil prices are:

In recent years, the world economy has been hit successively, and the demand side of oil has been suppressed; At the same time, shale oil production in the United States broke out, hitting record highs year after year. In this way, the increase of the supply side, the limited demand side and the oversupply are the reasons for the sharp drop in oil.

Foreign refined oil price adjustment mechanism is based on the real-time fluctuation of international crude oil price, but China is very lazy in this respect. China's refined oil price adjustment mechanism is adjusted once every 10 day, that is to say, even if the international oil price falls wildly in the first nine days, as long as it rises back on 10, China's oil price will stand firm.