One doesn't convert coal to oil. Coal to energy yes. And coal is very nice and important. Which is why china keeps its own reserves and imports so that if coal is limited due to depletion or price volatility, it uses some of its own.
China imports only 2/3 of its energy? That's amazing. India imports nearly 3/3 of its energy use lol just for a comparison. And this is china barely even using its own coal reserves.
Notice that china's energy security is stronger than Europe and US. It has better relations, ties, and mutual dependence with Iran, KSA, Russia!, And coal producers around the world. China also has more renewable sourced energy than almost the rest of the world combined. Those project goals are not even close to being met and already china produces more joules and watts from solar, hydro, and wind then what Europe or US does. Combine those and you'll get around how much energy china produces from renewables. Pipelines go through neutral to friendly countries as well.
what does Russia's equity overseas have to do with china? Those countries can try to block Malacca strait and honestly china can let them and those countries will collapse under the weight of just inflation within years. They would socially collapse within months. It would be these supply chain issues multiplied by 1000.
do you realise that the western world is begging china to restart production and let ships flow? They are in reality more dependent on china providing them with all those goods that make the world run on a dime. Without that they can pick either 500% inflation or surviving like it is the 19th century.
on tech, the west is actually just about as dependent on china than the other way around. China can make chips down to 14nm nodes already and has been for some time. Aircrafts too. They will just be less efficient and economical than leading western ones. But everything from designing the next consumer product to a transformer, is done in china. All the leading edge stuff is more Asian than it is western and in more domains than people realise, it's china.