US Energy Information Administration (EIA) reports that North Korea imported 15,000 barrels per day of crude oil from China in 2016, plus 6,000 bpd of refined products. This is about 1% of UK oil consumption. The EIA mentions that some trade may go unreported and therefore, the actual figures may be higher. The real question, in order to assess North Korea’s oil vulnerability and China’s leverage, is not how much North Korea consumes but how much of that consumption it could replace.
North Korea would need to liquefy about six million tonnes of coal to cover all of its 2015 reported oil imports. North Korea produces more than enough coal to do this; its total anthracite-coal exports, mostly to China, were reported to be 25 million tons in 2015, making North Korea the largest anthracite exporter in the world.
Beginning in 2006, North Korea carried out major building and upgrading work at the Namhung Youth Chemical Complex. North Korea built and expanded a major coal-gasification plan. Coal liquefaction amounts to coal gasification plus an added step. It is the very same technology.
An Oil Embargo plus sabotage of key facilities like Namhung would cause problems
Combining an oil embargo with action to sabotage or destroy key facilities would cause serious problems for North Korea.
North Korea can keep scraping by but there goes not a lot of redundancy or extra capacity in critical facilities or critical operations.