In this part we will try to expose some major faults related to practical dealing with
voluminous geological, geophysical and production data. We will concern, in
particular, problems the customers meet when they employ the software (data banks
and interpretation systems) built on relational DBMS foundation. In addition, we will
point to the semantic object-oriented database use as the possible way of involved
problems' solution.
Nowadays the relational DBMS's are rather commonly used for geological,
geophysical and production data manipulation. ORACLE occupies the leading
position. It is used as a platform to design many software complexes, such as, for
example, Finder (Schlumberger), PDS (IBM), PetroVision (CGG) and so on. These
and other packages also using relational DBMS's are actively introduced now not only
for particular tasks solving but for global data banks creation at the level of an
enterprise, corporation and even territorial-administrative district as well.
The relational DBMS's domination (ORACLE in the first place), their marketing
promotion by the Western companies have resulted in firm conviction that the table
data model is the most efficient and nearly the only acceptable means to operate
information. Meanwhile there are quite a few examples of successful use of above-
mentioned software packages. Their adaptation to meet peculiar customer conditions
takes, as a rule, the years, and hardware capacity requirements grow along with
soaring data volume.
An explanation of this contradictory situation seems to be as follows. Software
packages developed on non-relational databases are much lesser part of the software
market, and their developers do not possess appropriate marketing capacities. In
connection with this the relational approach is not challenged in practice by any
competitor. Therefore customers are deprived of possibility to be convinced that some
serious problems they meet with are not inevitable in principle but result from
inefficient approach to software design. Let us briefly specify most evident faults of
the relational DBMS's and problems they engender.
First thing one should note is that software packages utilizing the relational model
(usually ORACLE) make great demands on the hardware. Now use of workstations
for geological, geophysical and production data processing becomes quite common.
They are believed to be the only means to provide for currently necessary productivity
of data management process. There is not need to remind that the workstations are
rather expensive (as compared with the PC, for example) hardware. They not only cost
quite a lot but also require significant expenses and special equipment for
maintenance. To install the workstations is simply impossible or extremely
unprofitable in those industry departments where appropriate technical conditions are
absent (for example, in branches). High price and "capriciousness" of the
workstations become serious (may be crucial) obstacles to their widespread use. One
part of potential customers can not afford them due to lack of money while another
part can not exploit them on technical reasons as well (working in the field conditions
specialists are meant, for example).
Above-enumerated intrinsic to the workstations restrictions are not usually considered
as the faults. They are believed to be stipulated by the very reality. However having
known alternative methods of information tasks solutions (they will be told about
beneath) we have the right to assert that demand for the workstations use is stipulated
only by inefficient data model exploited software packages are based on.
Another serious fault we connect with the relational approach is a poor adaptability of
appropriate software tools to individual customer conditions. Relational databases
deal with strictly specified parameters sets, logical integrity of stored information
being ensured at the database query level (application level). Therefore, any
parameters specification change results in correction of not only database structure but
involved application software as well. Practice proves that such a database adaptation
may take the years. Meanwhile the industry enterprises' and corporations' activity
scope as well as employed technologies character are permanently changing. New
parameters categories periodically emerge. They need new positions to be allocated at
the data bank structure. The relational DBMS's use experience proves that they cope
with this problem rather badly. Table-located data volume growth as well as new tables
addition rather drastically reduce database queries efficiency. Upon such a difficulty
having occurred the customers are usually proposed to purchase new, more
sophisticated hardware and, later, suitable software too. As a rule, the customers
consider those measures as quite necessary. In such a manner the lion's share of funds
(about 80%) is usually spent on senseless, unproductive tasks solving. One can not
miss that the situation is extremely beneficial for numerous manufacturers of
workstation hardware and software.
To overcome involved problem the relational approach supporters suggest strict
standardization of both the data categories and data representation means. Actively
developed now standard POSC is an example of such an approach. One of the
problems it is intended to cope with is to foresee all data types to be probably dealt
with in the future. Taking into account high-grade data volatility and substantial data
processing methods difference at various enterprises one can easily conclude that the
attempt seems to be deprived of any logic.
Information logical integrity maintenance task (which is solved at the level of
relational database queries) compels the POSC standard developers to stipulate strict
binding of various data types. It is expressed in the rule that one category data must be
inserted into database or deleted only together with some other category data bound
with the former. Therefore, to comply with this rule inevitably compels the customer
to adjust his pertinent tasks to the software at his disposal.
As it was many times noted unfavourable for a customer situation results from the
inefficient database management system used as a foundation for proposed technology
solutions. We may assert that nowadays there is a real competitor with the relational
approach. Semantic object-oriented DBMS forming foundation of new data
management approach is almost completely deprived of above-mentioned defects.
The semantic DBMS important feature is an orientation to the objects which are
information models of objects, events and phenomena of the real world or, to be more
exact, of involved application field. In such a database any parameter value is
allocated as a single instance, this parameter presence in various objects description
being realized by means of special references mechanism. This ensures database
information minimal redundancy and, moreover, significantly reduces amount of
possible errors.
Every parameter being considered as a potential object results in perfectly painless
data sets upgrade.
Another important benefit is that redundancy absence and high-grade data logical
integrity provide noticeable reduction of requirements to the computer resources.
Enumerated benefits of the semantic object-oriented data model are confirmed by
profound but not well-known yet practice. Long-term use of the information analysis
system CTC-EXPERT under conditions of enterprises in Russia and the CIS
countries has proved that semantic DBMS CTC forming foundation of the fore-
mentioned system is an efficient data management tool deprived of all above-
enumerated faults. In the first place it is important to note that DBMS CTC operates
on the IBM PC platform. Computer equipped with Pentium processor and 2-Gbyte
hard disk is quite enough to realize storage and full-quality retrieval of exploration
and production data related to vast (more than ten thousand wells) oilfields. Such a
configuration provides roughly the same data retrieval efficiency which is attained at
the workstations using ORACLE. Benefits of the PC exploitation are evident: firstly,
much lesser cost of both the hardware and its maintenance and, secondly, computer
(computer technology) availability at virtually any industry sector including primary
departments and oilfield plots.
None computer technology is of any practical importance for an enterprise until it is
adapted to individual conditions. When geological and geophysical data bank is
meant, such an adaptation must take into account not only involved parameters
specification peculiarities and processing techniques, but also the ways of the data
import and export. The semantic DBMS allows us to react adequately to both of the
factors. Flexible DBMS makes it possible to accomplish its quick adaptation to the
customer conditions and to organize effective new technologies maintenance and
support. The semantic model is so universal that it permits us to consider data of
other structure (table, for example) as a subset of proprietary data. This fact is of great
significance for adaptation task because it allows us to include data files of various
formats to the semantic DBMS structure in a natural way.
Taking into account all above-stated one should conclude that choice of the semantic
DBMS is most prospective for data management in gas and oil industry. This
conclusion significance is confirmed by not only theoretic advantages the semantic
model possesses, but also current practice of industry enterprises information
maintenance organization. Relational databases (in particular, ORACLE) and founded
on them software prove to be unsatisfactory means of intended tasks resolution. On
the contrary, high data management efficiency reached with the semantic DBMS's
use confirms that in the nearest future they must become the foundation a majority of
software packages to be based on.