Page 27 - Geology and Geochemistry of Oil and Gas

6 SYSTEMS APPROACH IN SCIENCE

Earth’s crust. For this set (‘‘minerals’’) even its very volume is difficult to define due
to continuous evolution in nature. Some minerals combine to form a new mineral.
Therefore, the total volume of the set decreases. In some other cases, a mineral may
decompose into several minerals, and the volume of the set would increase. Upon
transformation, some minerals can acquire new properties (or transfer into other sets
located at different rungs of the hierarchical ladder). For instance, either chemical
elements (a rung down) or a rock may form (a rung up).
A set of bituminous minerals (beginning with antraxolites at the one end and
ending with oil and gas, at the other end) may be considered as an ‘‘open popu-
lation’’ in petroleum geology. In general, ‘‘open population’’ is a population (or set)
that can be expanded or reduced to some extent. It is distinguished from the ‘‘open
system’’ the main property of which is the exchange of the matter, energy, and
information with environment.
It is very difficult to select a significant parameter that could be used for a clas-
sification of such ‘‘open population’’ in compliance with the laws of formal logic.
The reasons for that are numerous: (1) complex interrelations; (2) different genesis;
(3) formation of different minerals (such as oil and gas) in the same environment;
conversely, one mineral (such as gas) can form in totally different environments; (4)
complex alterations and transformations when natural temperature and pressure
change. Even if, in order to create an accumulation type classification ‘‘by the com-
position’’, one narrows down the above ‘‘open population’’ to just three elements
(oil, gas, and condensate), the development of a natural classification will be very
difficult. There is a continuous series of objects present; there are endless numbers of
natural kinds and transition forms when habitat changes (including technological
changes, such as production). All these circumstances result in overlapping classes
and violations of the rules of formal logic of subdividing the whole concept.
Genetic parameters in geology and in particular, in petroleum geology, may play a
significant role. But how would one take them into account? A recommendation of
formal logic to define the particular through the general (or, as it is sometimes used
in natural sciences, to define species through the genus) is of little use in this sit-
uation.
If there is a natural hierarchical classification constructed in compliance with the
rules of subdividing the whole concept, then each species identified within a genus
(subset within a set) preserves the significant parameters of the genus. Conversely,
each species included in the genus preserves its significant species features. What
actually occurs is a formal addition or division of objects. This principle intrinsic to
the concept of naı¨ve materialism of ancient Greeks was preserved in formal logic
from the Aristotle’s times.
Everything is much more complicated in the hierarchy of geologic bodies. There,
the situation is tampered by genetic processes evolving under their own laws and
resulting in profound qualitative changes. Elements composing minerals (or other
chemical compounds), considerably change their properties. For instance, is there
any similarity in properties of gaseous oxygen and hydrogen with the same elements
forming a solid mineral or water? From the viewpoint of formal logic it would be
expected that simple summation of the lower rank objects will result in higher rank