--> Abstract: Digitizing Rocks? Standardizing the Geological Description Process Using Workstations, by M. R. Saunders, J. A. Shields, and M. R. Taylor; #90990 (1993).

Datapages, Inc.Print this page

SAUNDERS, MICHAEL R., EXLOG (Services), Windsor, Berkshire, England; JOHN A. SHIELDS, EXLOG NORTH SEA, Aberdeen, Scotland; and MICHAEL R. TAYLOR, EXLOG, Inc., Houston, TX

ABSTRACT: Digitizing Rocks? Standardizing the Geological Description Process Using Workstations

The preservation of geological knowledge in a standardized digital form presents a challenge. Data sources range in scale from the macroscopic (e.g., outcrop) through the mesoscopic (e.g., hand-specimen) core and sidewall core, to the microscopic (e.g., drill cuttings, thin sections, and microfossils). Each scale change results in increased heterogeneity and potentially contradictory data. Geological data are inherently "fuzzy." Finally, the providers of such data may vary dramatically in experience level. Hence the challenge!

To address these issues with respect to cores and drill cuttings, a geological description workstation has been developed and is undergoing field trials. Over 1000 carefully defined geological attributes are currently available within a depth-indexed, relational database. Attributes are stored in digital form, allowing multiple users to select familiar usage (e.g., diabase vs. dolerite). Data can be entered in one language and retrieved in other languages. The database structure allows groupings of similar elements (e.g., rhyolites into the acidic igneous or volcanics subgroups, or into the igneous rock group) permitting different users to analyze details appropriate to the scale of the usage.

Data entry uses a graphical user interface, allowing the geologist to make quick, logical selections in a standardized or custom-built format. Extensive menus, on-screen graphics, and help screens allow "point-and-click" selection. Description ranges (e.g., coarse to medium) are permissible. Error checking limits the potential for geological oxymorons. Entries for lithology, petrology, structures (sedimentary, organic and deformational), reservoir characteristics (porosity and hydrocarbon shows), and macrofossils are available. As data are selected, the on-screen geologist's impression is updated to provide immediate feedback, ensuring data correctness. Sampling points for thin sections, core analysis, geochemistry, or micropaleontology studies are also recorded.

Using digital data storage, geological logs using graphical, alphanumeric (both abbreviated and full word), and symbolic depictions are possible. Data can be amalgamated with drilling and mud gas data, MWD and wireline data, and off well-site analyses to produced composite formation evaluation logs and interpretational crossplots, thus enhancing the value of each data source through integrated information management.

AAPG Search and Discovery Article #90990©1993 AAPG International Conference and Exhibition, The Hague, Netherlands, October 17-20, 1993.