Mother Earth is manufacturing more petroleum through abiotic means. Supercritical carbon dioxide and superheated water, under the conditions of temperature and pressure, are forming hydrocarbon molecules at an enormous rate, on a scale unimaginable for even the largest and most advanced industrial thermal pyrolysis plant that could be conceived.
And here you thought petroleum was just some kind of dinosaur soup.
You need a lesson in hydrocarbon generation, migration, and accumulation. Maybe even a junior high science class. You really, really, think that oil is stable within the earth where the temperature is over 1000 degrees? Ever heard of a refinery?