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The AAPG/Datapages Combined Publications Database

CSPG Bulletin

Abstract


Bulletin of Canadian Petroleum Geology
Vol. 38 (1990), No. 1. (March), Pages 180-180

C.S.P.G. 1990 Convention, "Basin Perspectives"

Automated Previous HitDataNext Hit Previous HitProcessingNext Hit for the Geological Atlas of the Western Canada Sedimentary Basin [Abstract]

Shetsen, I.1, Mossop, G.D.1

ABSTRACT

Atlas mapping is fundamentally based on a number of existing digital Previous HitdataNext Hit bases, both public and private. The most important of these are the provincial files for index and stratigraphic Previous HitdataNext Hit, and the Canstrat files for lithology. Integrated computer Previous HitprocessingNext Hit of these Previous HitdataNext Hit bases is designed to perform automatic distillation of raw geological Previous HitdataNext Hit into map input information. In geological investigations, this Previous HitbasicNext Hit task is routinely undertaken manually by a geologist. However, given the size of the Atlas project, the vast volume of Previous HitdataNext Hit (~ 200,000 wells), the disparity of provincial Previous HitdataNext Hit bases, and the degree of redundancy and inconsistency in the Previous HitdataNext Hit, manual evaluation and filtering of the well Previous HitdataNext Hit would require commitment of time and effort far exceeding the available resources. Consequently, a series of programs has been developed for the purpose of automating as many steps of the preliminary Previous HitdataNext Hit assessment as possible. These programs comprise an electronic Previous HitdataNext Hit Previous HitprocessingNext Hit system that transforms the raw Previous HitdataNext Hit into first-cut map input, practically without human interaction. The geologist is requested only to supply a few parameters at the programs' initiation.

The core of the system is made up of about 50 procedures that integrate, filter and organize the Previous HitdataNext Hit for further Previous HitprocessingNext Hit. They perform an integrity check, eliminate redundant and unusable Previous HitdataNext Hit, correct errors, evaluate and merge revised (cloned) wells, identify stratigraphic synonyms, and build Previous HitdataNext Hit structures.

The filtered raw Previous HitdataNext Hit may be directed into one of three streams:

  1. Selection of an optimized set of control wells (Atlas Previous HitdataNext Hit base).
  2. Selection of an optimized set of control picks (Atlas standard set).
  3. Generation of map input from the entire bank of clean Previous HitdataNext Hit.

The Previous HitdataNext Hit derived by options (1) and (2) can be used directly for the generation of map input, or can be dispatched to a set of programs that evaluate Previous HitdataNext Hit conformity and variability through neighbourhood cross-reference and surface modelling. Reports on missing or potentially erroneous Previous HitdataNext Hit also can be produced. Feedback to the system (geologists' corrections) is assessed in the same way. Analysis and hierarchical classification of Previous HitsequenceNext Hit types within a specified stratigraphic slice is yet another option offered by the system, for both the raw and derived Previous HitdataNext Hit.

To perform the above tasks, the system requires some built-in analytical and pattern recognition capacities. When the program attempts to eliminate an inconsistency in the pick Previous HitsequenceNext Hit, or to isolate stratigraphic synonyms, it must make a decision that requires some understanding of stratigraphic relationships. Yet the diversity and complexity of the regional stratigraphy precludes the usage of reference tables as the system's guide. Thus, the programs extract the stratigraphic knowledge directly from the Previous HitdataNext Hit, by examining and storing the adjacency relations between picks, and using the stored information, together with a few optimization algorithms and heuristic rules, to arrive at geologically sensible decisions. It should be emphasized that although most of the post-selection Previous HitprocessingNext Hit concentrates on the 10,000 Atlas control wells, the system undertakes continuous evaluation of each well in the context of its neighbourhood (host township). This allows for properly assessed supplemental Previous HitdataTop to be brought to bear on the mapping, and minimizes the loss of information induced by selection.

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ACKNOWLEDGMENTS AND ASSOCIATED FOOTNOTES

1 Alberta Geological Survey, Edmonton T6H 5X2

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