* rock porosity and migration pathways for abiogenic petroleum [13]
* ocean floor hydrothermal vents as in the Lost City hydrothermal field;
* Mud volcanoes and the volatile contents of deep pelagic oozes and deep formation brines
* mantle peridotite serpentinization reactions and other natural Fischer-Tropsch analogs
* Primordial hydrocarbons in meteorites, comets, asteroids and the solid bodies of the solar system
o Primordial or ancient sources of hydrocarbons or carbon in Earth [14][15]
+ Primordial hydrocarbons formed from hydrolysis of metal carbides of the iron peak of cosmic elemental abundance (Cr, Fe, Ni, V, Mn, Co) [16]
* isotopic studies of groundwater reservoirs, sedimentary cements, formation gases and the composition of the noble gases and nitrogen in many oil fields
* the geochemistry of petroleum and the presence of trace metals related to Earth's mantle (Ni, V, Cd, As, Pb, Zn, Hg and others)

Similarly, research into the deep microbial hypothesis of hydrocarbon generation is advancing as part of the attempt to investigate the concept of panspermia and astrobiology, specifically using deep microbial life as an analog for life on Mars. Research applicable to deep microbial petroleum theories includes

* Research into how to sample deep reservoirs and rocks without contamination
* Sampling deep rocks and measuring chemistry and biological activity [17]
* Possible energy sources and metabolic pathways which may be used in a deep biosphere [18][3]
* Investigations into the reworking primordial hydrocarbons by bacteria and their effects on carbon isotope fractionation

A 2006 review article by Glasby presented arguments against the abiogenic origin of petroleum on a number of counts.[1]

A paper on abiogenic hydrocarbon production in a February 2008 issue of Science used data from experiments at Lost City (hydrothermal field) to report how the abiotic synthesis of hydrocarbons in nature may occur in the presence of ultramafic rocks, water, and moderate amounts of heat.