ABSTRACT: The Explorationists' GIS

Robert J. Coshey

Two commercially available programs, AutoCAD (a computer-aided drafting package) and dBASE IV (a relational database system), were combined to build a low-cost and flexible "geographic information system." The purpose was to accurately position varied exploration data on high-quality base maps in a time- and cost-effective manner. Related borehole information tables include: header, subsurface formation, drill stem test, completion/production test, core, bottom-hole location, and commercial subsurface. American Petroleum Institute (API) well numbers are used as the primary well identifiers and database relation links. In addition, congressional location and latitude/longitude index tags are available to aid in geographic searches.

Subsets of the database are extractable via spatial and/or other data content queries and exported to AutoCAD in standard ASCII format. Well data can also be directly imported into AutoCAD from several commercial data vendors. Spatial positioning is accomplished using latitude, longitude, and subsea elevation as a key. Latitude and longitude are converted to Universal Transverse Mercator rectangular coordinates for presentation in AutoCAD. Any data entered or edited in drawing attributes is extractable for database updating. Base maps are created by digitizing USGS 7.5 minute topographic maps directly into AutoCAD or by importing commercially available land grids.

This system is actively being used to construct, purify, and maintain a 2000+ well database and associated base maps for the purpose of hydrocarbon exploration in the Morrow Trend of southeast Colorado. Bledsoe Ranch field will be used as the GIS application example.

AAPG Search and Discovery Article #91002©1990 AAPG Rocky Mountain Section Meeting, Denver, Colorado, September 16-19, 1990