Barrel and ton are two commonly used units of crude oil. The crude oil unit of western countries such as the Organization of Petroleum Exporting Countries, Britain and the United States is usually expressed in barrels, while the crude oil unit of China and Russian countries is usually tons. The conversion relationship between tons and barrels is: 1 ton is about 7 barrels; if the oil quality is light (thin), 1 ton is about 7.2 barrels or 7.3 barrels. Gas stations in the United States and Europe are usually in gallons, while gas stations in China are priced in liters.

1 barrel = 158.98 liters =42 gallons. American l gallon =3.785 liters, British 1 gallon = 4.546 liters. If the volume is converted into weight, it is related to the density of crude oil.

Assuming that the density of crude oil in a local area is 0.99 kg/L, the weight of a barrel of crude oil is158.98x0.99 =157.3902kg..

Judging from the actual situation in 2005, there was no imbalance between supply and demand in the international crude oil market. After March 2005, the demand of crude oil market basically decreased month by month. However, the use of speculative funds to reduce the excess production capacity of the Organization of Petroleum Exporting Countries has caused the market to worry about the supply of crude oil, and has wantonly made many international crude oil futures, resulting in high oil prices. On February 28th, 2005, Xinhua News Agency reported that the Iranian oil minister suggested that the Organization of Petroleum Exporting Countries (OPEC) should consider reducing production, which led to a sharp rise in crude oil futures prices in the international market on February 28th. The futures price of low-sulfur light crude oil for delivery in the New York Mercantile Exchange in February this year rose by 1.66 USD per barrel, and the closing price rose to 59.82 USD. February futures price of Brent crude oil in North Sea on London International Petroleum Exchange rose 1.35 USD per barrel to close at 57.64 USD.