Computer Processing of Dipmeter Log Data: Enhancement of a Subsurface Exploration Tool

Abstract

The dipmeter is unique in that it is the only logging tool that provides information describing conditions outside the borehole. Reliable predictions of the structural configuration in surrounding rock units can be made by extrapolation of proper three-dimensional interpretations from computer processed results. The three-dimensional conceptualization required to decipher structural and stratigraphic information from dipmeter logs can be aided superlatively by the use of computer-generated displays, generally not provided by the well-logging service companies.

The significance of further manipulation of tadpole (arrow plot) data is emphasized. The variable components, graphic format, and geologic significance is demonstrated for the following plots: continuous azimuth vector plot, borehole deviation block diagram, fracture identification plot in azimuth space, SCAT (Statistical Curvature Analysis Techniques expounded by C. A. Bengtson of the USA) plots, and cross with which the borehole path dip components, formation boundaries, and structural axes are projected onto a vertical cross section of any orientation either intersecting the borehole or some distance away, perhaps along a seismic line. Production of these simple graphic illustrations is a task computers have been programmed to do quickly and unerringly. Once available these transformations save time, they provide a simple tool for interpretation, and they reveal the implicity of complex geologic terrains.