Accumulated domestic crude oil supply/demand balance, that deducts processing volume from the total supply of net imports and productions, reached 23.4 million metric tons in Jan-May 2018, according to the government stats. That throughout 2017 was 44.6 million mt. The monthly balance rarely shows negative figures and total accumulation since Jan 2006 attains 270 million mt.
However, China's National Bureau of Statistics said that strategic petroleum reserves in the nation are only 37.73 mt as of mid-2017. This volume was higher than a year ago by 4.48 million mt and the International Energy Agency estimated that China's SPR stood at 39.2 million mt as of end-2017.
Meanwhile, commercial crude oil inventories in China as of end-2017 were estimated at 27 million mt by Xinhua News. The latest figure as of end April 2018 was 27.4 million mt. The commercial crude oil inventories have been swung between 25 and 35 million mt during the 2010's. It is basically under the downward tendency after peaked in Sep 2014. Petroleum products inventories are also indicating a seasonal cycle and no significant upward trend is seen.
Therefore, the statistically calculated crude oil surplus is clearly larger than the actual increase in the stockpile. It is a mystery where the surplus is gone. Many people believe that Chinese stats are not reliable, but even that, the discrepancy looks too large.
Crude oil processing volumes released by the NBS are about 50 million mt recently. These figures are the sum of collected data from enterprises that have more than 5 million RMB of annual sales. Since oil refiners are unlikely to have less than US$0.8 million of annual sales, the processing volume could cover all eligible firms. Additionally, it is not realistic to estimate that those firms report much smaller production than they actually do.
Current estimated total of the strategic petroleum reserves and commercial oil inventories in China are close to 90 million mt. It equivalents to about 55 days of the nation's recent consumption volume. Although this level is still far from 90 days that is recommended by the OECD, a significant progress is seen as Chinese petroleum demand has doubled from a decade ago when its stockpile only covered less than a month of consumption.
On the other hand, China may have equipped nearly its 170 days of consumption equivalent petroleum stockpiles based on the above surplus calculation. However, we can't find their storage facilities for such large volume. Thus, it is reasonable to guess that import figures are overblown. Based on the discrepancy among estimated stockpiles, China's actual crude oil imports are likely to be below the customs reported volume by about 10%. Chinese influence in the global crude oil market should be discounted.