CC-SS - coupled crack-seal simulation

CC-SS - 耦合裂纹密封模拟

• 批准号: 391503625
• 负责人: Professorin Dr. Britta Nestler
• 金额: --
• 依托单位: Lehr- und Forschungsgebiet Geologie - Endogene Dynamik (GED) (aufgelöst)
• 依托单位国家: 德国
• 项目类别: Research Grants
• 财政年份: 2018
• 资助国家: 德国
• 起止时间: 2017-12-31 至 2022-12-31
• 项目状态: 已结题
• 来源: https://gepris.dfg.de/gepris/projekt/391503625?language=en
• 关键词: CC; SS; coupled; crack; seal

Syntaxial crack-seal veins are first order structures in deep, hydrothermal and reactive (THMC) environments where fluids create and moderate permeability and reactions interact with deformation. In recent work, we successfully modelled these veins using two different approaches: we used the Phase Field Method (PFM) to model epitaxial growth of Quartz from an aqueous solution, based on thermodynamic and kinetic principles but with simplified assumptions on crack geometry; in another study we used the Discrete Element Method (DEM) to model the growth of crack-seal veins in 3D, based on mechanical principles but with simplified assumptions on crystal growth. Here we propose to couple these two methods, to study the coupled thermal, hydraulic, mechanical and chemical evolution of syntaxial crack-seal veins in bi-directionally coupled PFM and DEM models. For this we will develop exchange routines to translate the spatial domains of DEM to PFM and vice versa, to model the fracturing process with DEM and the sealing processes with PFM. Observations of syntaxial vein microstructures will provide data on microstructure, vein crystal morphology and facet crystallography for comparison of our results with natural prototypes. The coupled models will lead to a better understanding of the feedback mechanisms between fracturing and sealing processes, quantify the evolution of mechanical and transport processes, help define new diagnostic microstructures in natural veins and form the basis for upscaling our models. A parametric study of syntaxial quartz and calcite veins will test hypotheses on (i) evolution of vein microstructure, (ii) rate of opening versus rate of crystal growth, (iii) relative strength of vein cement and host rock, and of the (iv) connectivity of vein porosity and evolution of permeability in hydrothermal, syntaxial crack-seal veins.

在深，水热和反应性（THMC）环境中，流体产生和中度渗透性和反应与变形相互作用的句法是一阶结构。在最近的工作中，我们使用两种不同的方法成功地对这些静脉进行了建模：我们使用相位场方法（PFM）对基于热力学和动力学原理的水溶液中石英的外延生长进行建模，但对裂纹几何形状进行了简化的假设；在另一项研究中，我们使用离散元素方法（DEM）根据机械原理对裂纹 - 密封静脉的生长进行建模，但简化了对晶体生长的假设。在这里，我们建议仔细研究这两种方法，以研究在双向耦合的PFM和DEM模型中，偶联的热，液压，机械和化学演化。为此，我们将开发交换例程，以将DEM的空间域转化为PFM，反之亦然，以用DEM和PFM建模压裂过程。对语法静脉微观结构的观察将提供有关微观结构，静脉晶体形态和小相结晶的数据，以比较我们的结果与自然原型。耦合模型将更好地理解破裂和密封过程之间的反馈机制，量化机械和运输过程的演变，有助于在天然静脉中定义新的诊断微观结构，并为提高模型的基础。句法石英和方解石静脉的参数研究将测试（i）静脉微观结构的演变，（ii）开口速率与晶体生长速率的速率，（iii）静脉水泥和宿主岩石的相对强度，以及（iv）静脉孔隙度和（iv）静脉孔隙率和渗透性渗透性中的静脉孔隙和进化的（IV）。