"...Since the nineteenth century, knowledgeable physicists, chemists, thermodynamicists, and chemical engineers have regarded with grave reservations (if not outright disdain) the suggestion that highly reduced hydrocarbon molecules of high free enthalpy (the constituents of crude oil) might somehow evolve spontaneously from highly oxidized biogenic molecules of low free enthalpy. Beginning in 1964, Soviet scientists carried out extensive theoretical statistical thermodynamic analysis which established explicitly that the hypothesis of evolution of hydrocarbon molecules (except methane) from biogenic ones in the temperature and pressure regime of the Earth’s near-surface crust was glaringly in violation of the second law of thermodynamics. They also determined that the evolution of reduced hydrocarbon molecules requires pressures of magnitudes encountered at depths equal to such of the mantle of the Earth..."
Several oil fields have already refilled in just a few decades and the reason we're seeing oil so cheap right today is because Russia is putting the theory to the test.
"The modern Russian-Ukrainian theory of abyssal, abiotic petroleum origins is not controversial nor presently a matter of academic debate. The period of debate about this extensive body of knowledge has been over for approximately two decades(Simakov 1986). The modern theory is presently applied extensively throughout the former U.S.S.R. as the guiding perspective for petroleum exploration and development projects. There are presently more than 80 oil and gas fields in the Caspian district alone which were explored and developed by applying the perspective of the modern theory and which produce from the crystalline basement rock.(Krayushkin, Chebanenko et al. 1994) Similarly, such exploration in the western Siberia cratonic-rift sedimentary basin has developed 90 petroleum fields of which 80 produce either partly or entirely from the crystalline basement. The exploration and discoveries of the 11 major and 1 giant fields on the northern flank of the Dneiper -Donets basin have already been noted. There are presently deep drilling exploration projects under way in Azerbaijan, Tatarstan, and Asian Siberia directed to testing potential oil and gas reservoirs in the crystalline basement."
I've been involved in drilling wells that were nearly 5 miles deep and I can assure you that they don't get better the deeper you go.