It could still bear a weird sort of fruit. We don't want to burn even all of our existing already-being-extracted oil fields, but chances are we'll always be e

It could still bear a weird sort of fruit. We don't want to burn even all of our existing already-being-extracted oil fields, but chances are we'll always be extracting some oil. So what's the highest quality, cheapest to extract, least environmentally damaging oil we could extract? Should we extract as much oil as we can from our current fields or shut them down and go elsewhere? Should we drain any field we are using completely dry or should we just take some from a lot of sites before shutting each down? Is it better to frack site A or put a deepwater rig at site B or a conventional well at site C? I could imagine a golden future where petroleum is a relatively minor but important resource, and where all the exploration now is a valuable dataset for deciding the most ethical way to extract it.