DOI: 10.5194/hess-22-1713-2018
Scopus记录号: 2-s2.0-85043359014
论文题名: Hydraulic characterisation of iron-oxide-coated sand and gravel based on nuclear magnetic resonance relaxation mode analyses
作者: Costabel S ; , Weidner C ; , Müller-Petke M ; , Houben G
刊名: Hydrology and Earth System Sciences
ISSN: 10275606
出版年: 2018
卷: 22, 期: 3 起始页码: 1713
结束页码: 1729
语种: 英语
Scopus关键词: Grain size and shape
; Gravel
; Groundwater
; Hydraulic conductivity
; Impurities
; Iron
; Iron oxides
; Mining laws and regulations
; Paramagnetism
; Pore size
; Relaxation time
; Sand
; Size distribution
; Grain size distribution
; Iron oxide-coated sands
; Kozeny-Carman equation
; Magnetic resonance relaxation
; Narrow pore size distributions
; NMR relaxation experiments
; Nuclear magnetic resonance relaxometry
; Relaxation time models
; Nuclear magnetic resonance
; borehole
; grain size
; groundwater
; hydraulic conductivity
; iron oxide
; laboratory method
; nuclear magnetic resonance
; pore space
; sand and gravel
英文摘要: The capability of nuclear magnetic resonance (NMR) relaxometry to characterise hydraulic properties of iron-oxide-coated sand and gravel was evaluated in a laboratory study. Past studies have shown that the presence of paramagnetic iron oxides and large pores in coarse sand and gravel disturbs the otherwise linear relationship between relaxation time and pore size. Consequently, the commonly applied empirical approaches fail when deriving hydraulic quantities from NMR parameters. Recent research demonstrates that higher relaxation modes must be taken into account to relate the size of a large pore to its NMR relaxation behaviour in the presence of significant paramagnetic impurities at its pore wall. We performed NMR relaxation experiments with water-saturated natural and reworked sands and gravels, coated with natural and synthetic ferric oxides (goethite, ferrihydrite), and show that the impact of the higher relaxation modes increases significantly with increasing iron content. Since the investigated materials exhibit narrow pore size distributions, and can thus be described by a virtual bundle of capillaries with identical apparent pore radius, recently presented inversion approaches allow for estimation of a unique solution yielding the apparent capillary radius from the NMR data. We found the NMR-based apparent radii to correspond well to the effective hydraulic radii estimated from the grain size distributions of the samples for the entire range of observed iron contents. Consequently, they can be used to estimate the hydraulic conductivity using the well-known Kozeny-Carman equation without any calibration that is otherwise necessary when predicting hydraulic conductivities from NMR data. Our future research will focus on the development of relaxation time models that consider pore size distributions. Furthermore, we plan to establish a measurement system based on borehole NMR for localising iron clogging and controlling its remediation in the gravel pack of groundwater wells. © Author(s) 2018. Citation statistics:
资源类型: 期刊论文
标识符: http://119.78.100.158/handle/2HF3EXSE/79365
Appears in Collections: 气候变化事实与影响
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作者单位: Federal Institute for Geosciences and Natural Resources, Wilhelmstraße 25-30, Berlin, Germany; Federal Institute for Geosciences and Natural Resources, Stilleweg 2, Hannover, Germany; Leibniz Institute for Applied Geophysics, Stilleweg 2, Hannover, Germany; North Rhine Westphalian State Agency for Nature, Environment and Consumer Protection, Leibnizstr. 10, Recklinghausen, Germany
Recommended Citation:
Costabel S,, Weidner C,, Müller-Petke M,et al. Hydraulic characterisation of iron-oxide-coated sand and gravel based on nuclear magnetic resonance relaxation mode analyses[J]. Hydrology and Earth System Sciences,2018-01-01,22(3)