Oil doesn’t come from huge caverns that we could drop trees into. Oil is often deep underground, soaked into porous rock. So wood would have to be liquified bef

Oil doesn’t come from huge caverns that we could drop trees into. Oil is often deep underground, soaked into porous rock. So wood would have to be liquified before attempting to pump it into oil wells, and it ruins the well for future use. Wood is valuable and other plant material is similar carbon/kg, so the low-hanging fruit is to take agricultural waste (currently burned or left to rot) and bury it. Hauling all that straw around burns a lot of fuel, so it’s not clear how well it scales compared to other approaches.