China's commercial crude stocks fell in December to their lowest level in 20 months, and dropped roughly 3 percent last year, according to Reuters calculations, as the world's second-largest oil consumer continues to build its strategic reserves.
The commercial stocks - which exclude strategic reserves - were down 0.7 percent at the end of December from the previous month, and refined fuel stocks were up 5.3 percent, the official Xinhua News Agency reported on Monday.
Diesel stocks grew 2.9 percent in December on weak industrial activity and infrastructure building, China Oil, Gas & Petrochemicals (OGP), a Xinhua oil and gas newsletter reported.
Gasoline recorded a 6.9 percent jump, to end the year at its highest level since September 2014, due to cold weather, the newsletter said.
Kerosene, used mostly as aviation fuel, also jumped, up 8.7 percent from the previous month on reduced travel demand.
Stocks for each of the three fuels were up in full-year 2015, according to Reuters calculations, with the combined inventories rising roughly 10 percent.
Last month, China imported a record 7.82 million barrels per day (bpd) of crude oil, and processed a record 10.79 million bpd, following a more than 70 percent slump in oil prices since mid-2014.
That left the country with an implied surplus of 185 million barrels in 2015, according to Reuters calculations, or 193 million barrels if changes in commercial inventories are factored in.
China rarely releases information on its strategic reserves, but did say they reached 190.5 million barrels by the middle of last year, an amount that exceeding some analyst estimates of the country's stockbuilding.