Presenter
Pania Newell
Engineering Sciences Center
Sandia National Laboratories
Abstract
The behavior of rock and earth structure is strongly affected by the confining stress. Many existing constitutive models lack the capability to describe the behavior of these materials over a wide range of confining stresses. In this talk, I will demonstrate a generalized plasticity model developed at Sandia National Laboaratories known as Kayenta as a capable constitutive model to capture the bahavior of geomaterials over wide range of loading. For instance, the Mount Simon Sanstone (Mt. Simon) is a heterogeneous formation with varying porosity, permeability, and mechanical properties. Lower Mt. Simon lithofacies are weaker and deform plasticially with modulus degradation, while the upper Mt. Simon lithofacies yields at higher shear stresses. An elasto-plastic model is a qualified choice to capture this range of constitutive response. Another unique feature of Kayenta is the capability to model joint sets. I will adopt this feature to investigate the impact of pre-existing fractures within caprock. Coupled multiphysics analysis of caprock integrity during CO2 sequestration will provide an insight into geomechnical behavior of subsurface storage systems.
