Geophysical log responses and their correlation with bed-to-bed stress contrasts in Paleozoic rocks, Appalachian Plateau, New York

A 1-km profile of in situ stress and geophysical log data was acquired in the Wilkins well to study the relationship between rock properties and in situ stress contrasts. Analysis of stress magnitudes and interval-averaged geophysical data shows that principal horizontal stress magnitudes correlate directly with elastic stiffness and inversely with clay content. A similar relation is found for older Paleozoic strata penetrated by a well at Auburn, New York. Correlations between stress magnitude and geophysical properties observed in the Wilkins and Auburn wells provide strong evidence that bed to bed stress variations arise from a unform ENE-WSW directed strain acting on beds of different Young's modulus rather than from variations in rock shear strength. -from Authors