Do not let the title of this post fool you. This post has nothing to do with abiotic oil generation.
While discussing EOR and CO2 sequestration with a co-worker, we both had noticed a note in a paper that we needed to be mindful of destroying newly discovered or undiscovered microbes and viruses present in the earths crust. What is ironic is that those organisms were discovered because of the oil and mining industry.
How much biomass do microbes contribute at depth, and are they sufficiently concentrated to be a significant contributor to oil and gas generation? I have seen several claims that the biomass of microbes in the crust could easily exceed the biomass of organisms on the surface or near surface. I’m not going to make any wild speculations, but it seems that there could certainty be some new target formations for oil and gas development.
Microbes may even source gas in igneous rocks. Unfortunately there is likely no way for the gas to be trapped in such a situation. Shallow biogenic gas is already targeted in many regions around the world. New consideration may need to be made for regions that have been overlooked in much deeper rock. Keep in mind the process for gas generation would likely not be the same. Shallow biogenic gas forms as a consequence of microbes metabolizing organics in the ground, and the deep gas targets could have some combination of microbes metabolizing minerals or organics (each other).
I really don’t have the time to research this subject properly, but if anyone happens to have seen any papers on the subject, please pass them along to me.