Japan consumes about 4 million barrels per day
NHK reports that Japan will release 'several days' worth of reserves. The nation is the world's fifth largest consumer of oil, at around 4 million barrels per day. So that's somewhere in the 12-24 million barrel range based on that stat. That sounds high but Japan has around 324 million barrels in reserves so they can swallow it.
A separate report says China is 'selling at least 7.3 million barrels from reserves' but a Global Times report earlier today said China should take a cautious approach because its own reserves aren't sufficient.
China might help the US curb soaring oil prices and fears of inflation by releasing its own crude oil reserves to a certain extent as a favor, experts said on Tuesday. But the US must return the favor with sincerity in pushing for a better environment for China-US cooperation, particularly it should refrain from heaping ungrounded pressure and crackdown on China in areas where they don't need China's help, experts said.
Here's a 30 minute chart of WTI. Let's just say the oil market isn't impressed:
