Mechanical Deformation, Failure Mode and Permeability Evolution in Carbonate Rock

构造变形和流体流动在许多地壳过程中是耦合的。在许多地球物理应用中，更全面地了解碳酸盐地层中的这一过程是很重要的。野外和室内观察表明，碳酸盐岩断层和变形带的发育明显比碎屑岩复杂，涉及的微力学过程根本不同。这可能会影响渗透率随变形和破坏模式的演化，以及它对应力和孔隙压力独立变化的响应。在本研究项目中，将采用基于实验室变形和渗透率测量、系统微观结构观察和微观力学分析的综合方法来解决与碳酸盐岩力学变形、破坏模式和流体流动相关的基本问题。显微结构和损伤发展将使用光学和扫描电子显微镜，以及x射线计算机显微断层扫描进行表征。综合宏观和微观数据，推导出不同破坏模式的细观力学模型和渗透率及相关有效应力行为的孔隙尺度模型。这项研究将提供一个不同寻常的机会来研究能源和构造学中主要关注的岩石物理问题。碳酸盐岩约占世界总量的60%。然而，由于碳酸盐岩储层的非均质性和复杂的微观结构，其表征仍然具有挑战性。在这种情况下，详细描述流体的渗透率如何随机械变形和应力（与构造和储层活动有关）而演变是至关重要的。这项研究将在实验室的受控条件下进行，目的是阐明这些问题的基础物理学。

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.