| DOI: | 10.2172/978017
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| 报告号: | DOE/ER 15738-1 Final Report
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| 报告题名: | Quantifying the Micromechanical Effects of Variable Cement in Granular Porous Media |
| 作者: | Goodwin, Laurel B.; Boutt David F.
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| 出版年: | 2010
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| 发表日期: | 2010-02-18
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| 国家: | 美国
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| 语种: | 英语
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| 英文关键词: | diagenesis
; sandstone
; porosity
; permeability
; elastic moduli
; compressive strength
; tensile strength
; DEM modeling
; poroelastic modeling
; ultrasonic velocity
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| 中文主题词: | 冰上通道
; 沉积物
; 成岩作用
; 水道
; 速度
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| 主题词: | LEADS
; SEDIMENTS
; DIAGENESIS
; VELOCITY
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| 英文摘要: | The mechanical and hydrologic behavior of clastic rocks and sediments is fundamentally controlled by variables such as grain size and shape, sorting, grain and cement mineralogy, porosity, and %cement - parameters that are not used directly in field-scale models of coupled flow and deformation. To improve our understanding of the relationship between these micromechanical properties and bulk behavior we focused on (1) relating detailed, quantitative characterization of the grain-pore systems to both hydrologic and mechanical properties of a suite of variably quartz-cemented quartz arenite samples and (2) the use of a combination of discrete element method (DEM) and poroelastic models parameterized by data from the natural samples to isolate and compare the influence of changes in the mechanical and hydrologic properties of granular porous media due to changes in degree of cementation. Quartz overgrowths, the most common form of authigenic cements in sandstones, are responsible for significant porosity and permeability reduction. The distribution of quartz overgrowths is controlled by available pore space and the crystallographic orientations of individual quartz grains. Study of the St. Peter Sandstone allowed evaluation of the relative effects of quartz cementation and compaction on final grain and pore morphology, showing that progressive quartz cementation modifies the grain framework in consistent, predictable ways. Detailed microstructural characterization and multiple regression analyses show that with progressive diagenesis, the number and length of grain contacts increases as the number of pores increases, the number of large, well-connected pores decreases, and pores become rounder. These changes cause a decrease in pore size variability that leads to a decrease in bulk permeability and both stiffening and strengthening of the grain framework. The consistent nature of these changes allows us to predict variations in hydrologic and mechanical properties with progressive diagenesis, and explore the impact of these changes on aquifer behavior. Several examples of this predictive capability are offered. In one application, data from natural sandstones are used to calibrate the proportionality constant of the Kozeny-Carman relationship, improving the ability to predict permeability in quartz-cemented quartz arenites. In another, the bond-to-grain ratio (BGR) is used to parameterize a discrete element model with data acquired from sandstone samples. The DEM results provide input to poroelastic models used to explore the hydrologic, mechanical, and coupled hydrologic and mechanical response of the sandstone to pumping stresses. This modeling exercise shows that at the macro-scale, changes in mechanical and hydrologic properties directly influence the magnitude and area of aquifer deformation. The significant difference in sensitivity of the system to the mechanical properties alone versus its sensitivity to coupled mechanical and hydrologic properties demonstrates the importance of including hydrologic properties that are adjusted for changes in cementation in fluid storage and deformation studies. The large magnitude of radial deformation compared to vertical deformation in these models emphasizes the importance of considering three dimensional deformation in fluid flow and deformation studies. |
| URL: | http://www.osti.gov/scitech/servlets/purl/978017
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| Citation statistics: |
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| 资源类型: | 研究报告
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| 标识符: | http://119.78.100.158/handle/2HF3EXSE/40010
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| Appears in Collections: | 过去全球变化的重建
影响、适应和脆弱性
科学计划与规划
气候变化与战略
全球变化的国际研究计划
气候减缓与适应
气候变化事实与影响
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| 978017.pdf（1465KB） | 研究报告 | -- | 开放获取 | | View
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| Recommended Citation: | |
Goodwin, Laurel B.,Boutt David F.. Quantifying the Micromechanical Effects of Variable Cement in Granular Porous Media. 2010-01-01.
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