Mechanical and anisotropic properties of the Duvernay Formation

A comprehensive understanding of the mechanical properties of shale formations facilitates safer and more efficient hydrocarbon development. We assess the mechanical properties and anisotropic behavior of the Duvernay Formation in Alberta using the results of laboratory tests conducted on formation core samples. The laboratory test results analyzed in this study include unconfined compressive strength, triaxial compression, Brazilian tests, and ultrasonic wave velocity tests on core samples cut at various orientations to the stratigraphic bedding planes. All laboratory test results analyzed in this study were retrieved from publicly available Alberta Energy Regulator-filed core analysis reports. The Thomsen anisotropy parameter findings indicate vertical transverse isotropy in the Duvernay core samples, largely influenced by clay content. Our analysis indicates that the mechanical properties of these Duvernay core samples also reflect this anisotropic behavior. Additionally, we develop a relationship between dynamic and static Young’s moduli and also investigate the differences in Young’s modulus during loading and unloading phases. The findings of this study, particularly the characterization of anisotropic mechanical properties, have practical implications for optimizing drilling operations and guiding hydraulic fracturing design in the Duvernay Formation.