Magnetic Susceptibility Logs from Sedimentary and Volcanic Environments


by Philip Nelson,
U.S. Geological Survey

SPWLA 34th Annual Logging Symposium, June 13-16, 1993



Magnetic minerals in sediments are of practical interest in petroleum settings because they can cause anomalous readings on some logs, can be indicators of diagenetic processes, and in some cases can directly affect reservoir quality. Recent papers modeling induction log response show that tile (11.1adratUre component is perturbed by thin magnetic beds having susceptibility values on the order of 600 /tSI. The density and photoelectric logs also respond to the presence of magnetic minerals.