Page 238 - Geology and Geochemistry of Oil and Gas

206 MATHEMATICAL MODELING IN PETROLEUM GEOLOGY

distinct boundaries, these systems exchange matter, energy, etc. with the external
medium. The geologic systems also develop in time. They, however, provide the
certain stability and inherit main structural and behavioral features of the system.
Depending on the kind of exchange between the geologic system and external me-
dium (exchange of substance, energy, or information, separately or simultaneously),
one can construct various types of models of oil- and gas-bearing systems. The
classification of the main features of natural geologic and engineering-technologic
systems is shown in Fig. 11.1.
The systems’ approach to geology is both a sophisticated philosophy and a sci-
entific method for investigation of very complicated geologic systems. As applied to
petroleum geology, it includes the methodological base and technology of mathe-
matical simulation used for modeling geologic systems, the systems, which have been
previously investigated and estimated by using experimental or field data. Inasmuch
as geologic systems develop in time, it is very important to simulate them as dynamic
systems. The necessity of taking the geologic time factor into consideration does not
eliminate the possibility of developing, along with the dynamic models, also of the
static and structural models. It is imperative, however, to remember that geology is a
historic discipline, and the relative lack of success in its mathematization is associated
to a significant degree with difficulties in taking into consideration the time factor.
Scientific bases, simulation techniques, and mathematical models of both static
and dynamic geologic systems have been developed, and basic theoretical and
methodological principles of simulation and prediction of geologic systems (their
structure and behavior) have been defined (Buryakovsky, 1992). These principles are
as follows:
1. Principle of consideration of the system’s nature requires a separate simulation of
geologic, technologic, and experimental systems with different objectives required
by the ‘‘real world’’.
2. Principle of system’s development (evolution) requires the simulation of systems
considering the time factor and its subdivision into three time scales: (a) geologic,
(b) technologic, and (c) experimental.
3. Principle of consideration of comparative size and complexity of geologic, tech-
nologic, and experimental systems requires simulation of a sequence of systems
from an oil- and gas-bearing basin through oil and gas field to core sample scale.
4. Principle of consideration of the information growth requires simulation of the
activities of earth scientists. These include the successive phases of prediction of
oil and gas presence and existence of traps, and discovery, exploration, reserve
estimation, development, and production of oil and gas fields.
The definition of these principles provides the systems’ approach both in the
development of the scientific foundations and in the simulation technology of ge-
ologic systems. The relations among simulation principles are given as a flowchart in
Fig. 11.2. An important element of this chart is the feedback, which allows im-
proving the present and developing the new methods for investigation and simu-
lation of geologic systems.
The technological chart (Fig. 11.3) distinguishes three inlet blocks: (1) theoretical
foundations (basic principles), (2) initial information, and (3) technical means