Mechanical Deformation, Failure Mode and Permeability Evolution in Carbonate Rock

在许多地壳过程中，构造变形和流体流动是相互耦合的。更全面地了解碳酸盐岩地层中的这些过程在许多地球物理应用中具有重要意义。野外和实验室观测表明，碳酸盐岩中断层和变形带的发育明显比碎屑岩中复杂，涉及根本不同的微观力学过程。这可能会影响渗透率随变形和破坏模式的演变，以及它如何响应应力和孔隙压力的独立变化。在本研究项目中，将使用基于实验室变形和渗透率测量、系统的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中的机械变形、破坏模式和流体流动有关的基本问题。微观结构和损伤的发展将采用光学和扫描电子显微镜，以及X射线计算机断层扫描的特点。综合宏观和微观数据，将导出不同破坏模式的微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难得的机会来研究能源和构造学中主要关注的岩石物理问题。碳酸盐岩约占世界的60%？碳酸盐岩储层的非均质性和复杂的微观结构使其表征仍然具有挑战性。在这种情况下，它是至关重要的，在一定程度上，表征流体的渗透性如何可能与机械变形和应力（与构造和储层活动）演变。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本物理学。

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.