Mechanical Deformation, Failure Mode and Permeability Evolution in Carbonate Rock

Suny At Stony Brook, Stony Brook NY

Investigators

Abstract

Tectonic deformation and fluid flow are coupled in many crustal processes. A more comprehensive understanding of such processes in carbonate formation is of importance in many geophysical applications. Field and laboratory observations show that the development of faults and deformation bands in carbonate rocks is significantly more complex than in clastic rocks, involving fundamentally different micromechanical processes. This is likely to impact the evolution of permeability with deformation and failure mode, as well as how it responds to independent changes of stress and pore pressure. In this research project, fundamental questions related to mechanical deformation, failure mode and fluid flow in carbonate rock will be addressed using an integrated approach based on laboratory deformation and permeability measurements, systematic microstructural observations and micromechanical analysis. The microstructure and damage development will be characterized using optical and scanning electron microscopy, as well as X-ray computed microtomography. The macroscopic and microscopic data will be synthesized to derive micromechanical models for the different failure modes and pore-scale model for permeability and related effective stress behavior. This research will provide an unusual opportunity to examine a rock physics problem of major concern in energy resources and tectonics. Carbonate rocks contain about 60% of the world?s oil reserves, and yet the characterization of carbonate reservoirs remains challenging because of their heterogeneity and complex microstructure. In this context, it is of critical importance to characterize, in some detail, how the permeability of fluid may evolve with mechanical deformation and stress (associated with tectonics and reservoir activities). The research will be conducted under controlled conditions in the laboratory with the goal to elucidate the fundamental physics for these issues.