A workflow to model anisotropy in a vertical transverse isotropic medium

This paper reviews elastic property changes in anisotropic mediums and proposes a workflow to model elastic stiffness tensor using conventional well logs in a vertical transverse isotropic medium. The proposed workflow uses the concept of downscaling and then upscaling of normal logs using Backus model and rock physics modeling which couples different effective medium theories together. The choice of the rock physics model depends on the anisotropy source in the given medium. Rock physics modeling is the main step in this workflow, and is very important in defining the final elastic constants of the medium. It is the place where all anisotropy information is integrated with the log information. Finally, this workflow is tested on the Duvernay shale formation in the western Canadian sedimentary basin where log data along with the laboratory core measurements are available. The good match between modeled and measured velocity confirms the validity of this workflow.