ABSTRACT: PLAYMAKER: A Knowledge-Based Approach to Characterizing Hydrocarbon Plays

Gautam Biswas, X. Yu, W. J. Hagins, J. S. Strobel, C. G. St. C. Kendall, R. L. Cannon, J. C. Bezdek

Present-day methods for prospect analysis include structural and facies analysis to identify traps; data come from outcrops, well logs, and seismic lines. PLAYMAKER adopts a more comprehensive geologic model based on basin analysis, which includes understanding of the geologic history of the basin and determining where potential source rocks and traps could be located in the basin.

The system uses a knowledge-based approach to acquire, from the user, interpreted data information, which helps characterize plays and prospects. Some characteristics, such as the sediment type, geometry, and facies models relate to the essential components of a hydrocarbon-bearing prospect: source rock, reservoir, and seal. Other characteristics, such as the tectonic setting, structural style, and history of the basin in which the prospect or play is located, provide background information for further understanding of the play or prospect. Still other characteristics are specific to individual components, such as the qualitative parameters that allow geologists to predict reservoir porosity and permeability, the nature of the seal, and the organic content of the source rock.

Relations between interpreted data sources and the required play characteristics are necessarily judgmental. They are developed into if-then rules with associated belief values to express the strength of the judgmental associations. Version 1 of PLAYMAKER, implemented using a partitioned rule-base approach, was found to have a number of deficiencies. We concentrate on version 2 of PLAYMAKER, where the knowledge base is redesigned, to remove some limitations of version 1, as a two-level hierarchy. An additional feature of version 2 is an interactive editor for modifying the system's knowledge base.

AAPG Search and Discovery Article #91003©1990 AAPG Annual Convention, San Francisco, California, June 3-6, 1990