Because Brent crude oil is in the North Sea, and the North Sea oil field is beginning to age. The quality of Brent crude oil itself is very good, second only to Texas Intermediate crude oil (WTI), which will be transported to a place called Cushing for storage, and the oil pipeline to the Gulf of Mexico will not be completed until 20 13. So before this, the liquidity of WTI crude oil was much lower than that of Brent crude oil. Originally, the prices of these two oils were similar. On the one hand, the aging of Beihai Oilfield and the decrease of oil production make WTI less internationalized than Brent, which leads to the higher price of Brent crude oil and better quality than other oils except Brent. But Europe also depends on the quality of Brent, and the heavy oil mined in other places can't meet the requirements of some European refineries. That's why Brent stands out.