Water-Assisted Time-Dependent Compaction of Natural Quartz Sands

天然石英砂的水辅助随时间压实

• 批准号: 9218793
• 负责人: Andrew Hajash
• 金额: $ 9.2万
• 依托单位: Texas A&M Research Foundation
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 1993
• 资助国家: 美国
• 起止时间: 1993-01-01 至 1995-12-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=9218793&HistoricalAwards=false
• 关键词: Water; Assisted; Time; Dependent; Compaction

This collaborative research explores the physico- chemical means by which sediments deposited at the earth's surface become lithified during burial. Solution-transfer creep is a possible mechanism, but the kinematics are not well defined. Experiments at Texas A&M University will monitor rates of pore-volume loss and water-rock interaction in sand-water mixtures under hydrostatic and nonhydrostatic conditions as a function of temperature, confining pressure, fluid pressure, grain size, clay content and aggregate volume strain. These will be performed in reactively inert pressure vessels that simulate temperature and pressure conditions typical of diagenesis. Experiments at University of Oklahoma will be conducted in a similar vessel, but with the added capabilities of triaxial loading and constant fluid flow. This effort will study compaction as a function of applied differential stress, study stress-related sand- water reaction kinetics, long-term constant flow conditions, and effects of solution undersaturation on compaction rates. data sets for both institutions will be interpreted in terms of constitutive "creep" laws for time-dependent volume strain, and together with reaction rate laws of mineral- water interaction under nonhydrostatic conditions (also experimentally determined), will be extrapolated to geological scenarios using numerical methods. The aim of this research is ultimately to quantify rates of pore-volume loss in sandstones during burial and to understand the thermodynamics kinetics of water-rock interaction under hydrostatic and nonhydrostatic conditions.

这项合作研究探索了沉积在地球表面的沉积物在埋藏过程中变得石化的物理化学方法。溶液转移蠕变是一种可能的机制，但运动学还没有很好的定义。德克萨斯A&M大学的实验将监测静水和非静水条件下砂水混合物中的孔容损失和水-岩相互作用的速率，作为温度、围压、流体压力、颗粒大小、粘土含量和集料体积应变的函数。这些将在反应性惰性压力容器中进行，这些容器模拟成岩作用典型的温度和压力条件。俄克拉荷马大学的实验将在类似的容器中进行，但增加了三轴加载和恒定流体流动的能力。这项工作将研究压实作为外加差异应力的函数，研究与应力相关的沙水反应动力学，长期恒定流动条件，以及溶液不饱和对压实速率的影响。这两个机构的数据集将根据随时间变化的体积应变的本构“蠕变”定律进行解释，并将与非静水条件下矿物-水相互作用的反应速率定律(也是通过实验确定的)一起，使用数值方法外推到地质情景中。这项研究的最终目的是量化砂岩在埋藏过程中的孔容损失速率，并了解在静水和非静水条件下水-岩相互作用的热力学动力学。