I did a lazy ask google, and it thinks less than 3% of crude oil is used for energy. The vast bulk of oil being used: 'transportation (gasoline, diesel, jet fuel), heavy machinery, and non-energy uses like asphalt and plastics rather than power plants'.

That is of course, one of the big problems of 'going green' - electricity production is low hanging fruit and understood by the general public.

When that's 'solved' (solar, wind, geo, nuclear), how do we solve the other 97%?

Oil really isn't going anywhere. It will be a slow tail, perhaps too slow to stop emissions.

https://www.iea.org/world/oil

Around 50% is used for road transport, though, which is poised to be replaced and was one of the parent poster's main points.

We knew how to make synthetic hydrocarbon one hundred years ago. Nazi Germany used the Fischer Tropsch process to make synthetic fuel after the Royal Navy blockaded their oil import. The only reason we're still digging up fossil fuel is because it's cheap. According to some calculation, green hydrocarbon from atmospheric CO2 and electrolytic hydrogen could be commercially viable when fossil petroleum reaches $200/barrel , which is really not that far off.