Abstract: Computer Graphic Displays of Dipmeter Information as Aids to Interpreting Complex Geology

L. H. Bell, L. M. Grace

The dipmeter is one of the most informative logs run in a borehole. Nevertheless, it rarely is applied to its full potential for solving geologic problems because spatial relations are not obvious from the computer listings and arrow plots supplied by logging companies. Auxiliary displays must be selected to make the data easier for the geologist to interpret. A computer is the only practical means of generating these diagrams. There are three main types of diagrams: statistical, geometric projections, and computation-results displays. Statistical plots include azimuth-frequency diagrams, modified Schmidt plots, stereographic projections, and data cross plots. These are used to estimate sand-body geometry and depositional environments, to resolve low-angle structural dips and to detect anomalies. The purpose of geometric projections is to present dipmeter information in pictures which closely resemble the borehole and rock. They include vertical cross sections, variously annotated maps, projections to inclined planes, and stereoscopic pairs for three-dimensional viewing. Data from many wells can be displayed simultaneously. Displays of data calculated from dipmeter information include those for removing structural dip to enhance stratigraphic analysis, extrapolations to various datums to generate contour maps and detect faults, and fundamental structural measurements such as apparent dip, axial planes, and intersections. Because a large part of solving any geologic problem is seeing all available data clearly in proper relation, auxiliary plots of dipmet r data are important geologic tools.

AAPG Search and Discovery Article #90968©1977 AAPG-SEPM Annual Convention and Exhibition, Washington, DC