Present and Future Geologic Applications of Petrographic and Other Image Analysis

FULL, WILLIAM E., Wichita State University, Wichita, KS

Relatively simple and inexpensive (some less than $2500) imaging hardware has provided the potential for the capture and analysis of great quantities of useful rock information. A common petrographic imaging system can be trained to identify the holes in rocks; from this collection of pores, variables such as permeability, recovery potential, and diagenetic history can be calculated for many rocks. Relationships between rock properties and petrophysical logs can also be ascertained and quantified in many instances. For many companies, petrographic image analysis has become a commonplace procedure.

The techniques involved with geologic image analysis derive directly from cancer research and other pattern-recognition-based studies. As these studies have advanced, so do the potential applications for the petroleum geologist. Intelligent software can be used to determine the volume of clay in a thin section and further subdivide the volume into framework clay, clay lining the pore network, and isolated particles. Techniques that quantify textures can be used to determine mineralogy, classify depositional environment, and sort out diagenetic history. Essentially, anything the eye can see in a rock, image analysis can capture. Furthermore, newer statistical approaches can extract meaningful and useful information from the "captured" data.

On the macro scale, image analysis can be used to describe larger scale core properties. Many of the macro techniques are based on satellite imaging techniques in conjunction with map comparison algorithms. On both the macro and micro scales, fractures can be identified and subsequently quantified similar to lineation analysis, thus offering access to information quite useful to the petroleum geologist. It is anticipated that most petroleum geologists will have access to some sort of image analyzer within the next 5-10 years.

AAPG Search and Discovery Article #91008©1991 AAPG Mid-Continent Section Meeting, Kansas Geological Society, Wichita Kansas, September 22-24, 1991 (2009)