In Situ Stresses in Low Permeability, Nonmarine Rocks

摘要

In situ stress measurements have been performed over a 2500-ft (760-m) interval in the nonmarine section of the Cretaceous Mesaverde in the Piceance basin in Colorado. These measurements include 27 hydraulic fracture measurements of the minimum in situ stress and 22 anelastic strain recovery (ASR) measurements. Stress data were obtained in sandstones, shales, mudstones, siltstones and coals and show the effect of lithology on the magnitudes of the stresses. Most tests in nonreservoir, clay-rich rocks had stress magnitudes near the lithostatic value, while reservoir rocks had considerably lower stress magnitudes. Stress orientations in these channel and meander belt sandstones were consistent throughout the section and showed no variation with channel direction. Where available, these results are compared with other techniques that give stress orientation and magnitude and consistent results are found. (ERA citation 12:026015)