Page 176 - Geology and Geochemistry of Oil and Gas

ROLE OF ENERGY IN THE OIL GENERATION PROCESS 145
the sedimentary cover. Sh. F. Mekhtiyev, B. A. Sokolov, etc. (in: Eremenko and
Chilingar, 1996) allow some participation of the convection energy in the oil gen-
eration. This is quite plausible based on what we know about the Earth’s coats/
covers. The proponents of inorganic origin insist that the petroleum accumulations
form by convection only. This statement is ruled out by the majority of scientists
although neither side has a convincing proof.
It will be very hard to prove that the (gas, liquid?) flows that exist can form
hydrocarbon accumulations with a pressure of 50 MPa or greater. At least, there are
no known gas deposits associated with subcrustal sources and containing enough
hydrocarbons at a sufficient pressure. A concept developed long ago by Stadnikov
(1931, 1937) suffered from the fact that there is insufficient amount of hydrogen in
the Earth’s crust. Crude oil differs from the living matter in its absence of oxygen
and over-abundance of hydrogen. Thus, Stadnikov (1937) had to introduce the
concept of hydrogenation by the hydrogen migrating from great depth.
Molchanov and Gontsov (1992) suggested that hydrocarbons can be synthesized
at room temperature and normal pressure in a medium capable of generating hy-
drogen. Hydrogen forms from the interaction between water and oxidizing minerals
that contain the sulfide of sulfur and protoxide of iron. Atomic hydrogen reacts with
the carbon (i.e., prior to the formation of H 2 molecules). The energy source is the
dispersed mineral mass.
Molchanov and Gontsov (1992) consider the oil generation as a chain conjugate-
radical reaction initiated by the hydrogen at the moment of its ‘‘release’’. The
mechanism of radical reactions was first suggested by Maksimov et al. in 1959. This
proposal was later supported by the discovery of free radicals in crude oils (this was
not known in 1959). This concept was developed further by Galimov (1973). He
concluded that the reactions, which are thermodynamically impossible at given
temperatures, may actually take place. Thus, heat is not necessary and is not a
required precondition for the oil and gas generation (Galimov, 1973, p. 223). Price et
al. (1985), Rohrback et al. (1984), and Nesterov and Shpilman (1987) also stressed
the importance of radical reactions in the formation of hydrocarbons.