The FMS tool makes extremely dense conductivity measurements, approximately 7000 per foot. These measurements have been most commonly used to generate images approximating core photographs. The images have been used for geological interpretation and fracture identification.

The main issue addressed in this paper is the comparison of rock property measurements made at different length scales. Small core plugs are often taken to represent larger sections of conventional core and comparisons are made with logs. FMS data can provide a quantitative measure of the variation that can be expected from this process. This measurement can be used to estimate the required sampling density of core plugs necessary to represent the formation in the vicinity of the wellbore to a specified degree of accuracy. It can also be used to determine the expected degree of agreement when comparing core and log data.