There is a well known problem that must first be overcome.

When the first wells were drilled they were drilled until they hit oil. Then everyone bought big houses and fancy cars. Then the money ran out.

So old fields were reopened with the theory that there was more than one pay zone under the ground. And this theory was correct. First: A pay zone is a layer of sand, or today it might be shale, that is laid over by a layer of (usually) limestone. Drill into the pay zone, suck out the oil. Drill through the pay zone, through the limestone beneath it, and sometimes (Actually usually) there is another pay zone beneath it. Yeh! More big houses! More fancy cars!

Then drill to the next and to the next until you reach depths where the temp and pressure is beyond anything a current drilling rig can penetrate. And that's where you stop.

So deeper hydrocarbons are nothing new. What needs to be new is a cost effective way to reach them.

And I wonder what blowout preventer could deal with the forces found in a volcano?