CHINA imported record volumes of crude oil in September, eclipsing the United States as the world’s top buyer.

China’s September crude oil imports rose 18 percent from a year earlier to 33.06 million tonnes or 8.04 million barrels per day (bpd), customs data showed. The buying outpaced the U.S. four-week average assessed by the U.S. Energy Information Administration to be at 7.98 million bpd as at the end of September.

It also marked the second time this year but the third month in the past twelve months that China’s imports have overtaken the United States, and reflected contracts signed in July when renewed selling pressure pushed crude below $42 a barrel.

Oil has since recovered to over $50 a barrel. The shipments also arrived as Chinese refineries entered the final stretch of their annual maintenance season, which typically takes place in the third quarter.

With U.S. plants’ repair work extending into this month, the world’s largest economy could retake pole position in October, analysts said. China’s strategic reserve is preparing to start filling late this year newly-built storage tanks that can take some 19 million barrels of crude, or about three days worth of imports, traders said.

“The increase was mainly driven by stocking activities at some reserve sites,” said Harry Liu, associate director of oil markets with IHS Energy, (an information and data provider), who said August and September volumes were higher than he expected. That contrasts with earlier in the year when China’s independent refiners known as “teapots” were the driving force behind the imports. Analysts from BMI research, a Fitch Group, expected China’s crude imports to remain elevated for the rest of the year due to falling production, expanding storage capacity and a seasonal uptick in demand over the winter months.