Pore geometry of sandstone derived from pulsed field gradient NMR

Pape, H.; Tillich, Joachim E.; Holz, Manfred

doi:10.1016/j.jappgeo.2005.07.002

Cited by 66 publications

(37 citation statements)

References 27 publications

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“…The tortuosity is set to 1.5 in this study, which is a reliable estimate for coarse sand and gravel (e.g. Pape et al, 2006;Dlugosch et al, 2013). …”

Section: Estimation Of Effective Pore Radius and Hydraulic Conductivimentioning

confidence: 99%

Hydraulic characterisation of iron oxide-coated sand and gravel based on nuclear magnetic resonance relaxation modes analyses

Costabel¹,

Weidner²,

Müller‐Petke³

et al. 2017

Preprint

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Abstract. The capability of nuclear magnetic resonance (NMR) relaxometry to characterise hydraulic properties of iron oxide-10 coated sand and gravel was evaluated in a laboratory study. Past studies have shown that the presence of paramagnetic iron oxides and large pores as present 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 15NMR 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 estimating a unique solution yielding the apparent capillary radius from the NMR data. We found the NMR-based apparent radii to 20 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 KozenyCarman 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 allow for broader pore size distributions.Furthermore, we plan to establish a measurement system based on borehole NMR for localising iron clogging and controlling 25 its remediation in the gravel pack of groundwater wells.

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“…The tortuosity is set to 1.5 in this study, which is a reliable estimate for coarse sand and gravel (e.g. Pape et al, 2006;Dlugosch et al, 2013). …”

Section: Estimation Of Effective Pore Radius and Hydraulic Conductivimentioning

confidence: 99%

Hydraulic characterisation of iron oxide-coated sand and gravel based on nuclear magnetic resonance relaxation modes analyses

Costabel¹,

Weidner²,

Müller‐Petke³

et al. 2017

Preprint

View full text Add to dashboard Cite

show abstract

“…Electrical resistivity or diffusion measurements are used to estimate Γ by some authors e.g., Berryman and Blair (1987), Cornell and Katz (1953), Dullien (1975), Pape et al (2006), Walsh and Brace, (1984).…”

Section: Accepted Manuscriptmentioning

confidence: 99%

“…However, tortuosity for hydraulic flow would not necessarily be the same as tortuosity for diffusion and electrical conduction (Bear, 1972;Carman, 1937;Pape et al, 2006). Whereas diffusion and electrical conduction in a pore have a piston-like displacement, fluid flow has a velocity profile with a lower velocity on the fluid-mineral interface.…”

Section: Accepted Manuscriptmentioning

confidence: 99%

Permeability in Rotliegend gas sandstones to gas and brine as predicted from NMR, mercury injection and image analysis

Rosenbrand

Fabricius²,

Fisher

et al. 2015

Marine and Petroleum Geology

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“…At present, there are a series of experimental methods such as scanning electron microscopy (SEM) [19][20][21][22][23][24][25][26][27][28][29][30][31], mercury intrusion porosimetry (MIP) [5,[32][33][34][35][36], and low-field nuclear magnetic resonance (NMR) [35][36][37][38][39][40] which have been widely applied for qualitative and quantitative determination of pore structure characteristics of different types of reservoir rocks. Among them, high resolution SEM-based imaging techniques, for example, field emission SEM (FE-SEM) [19,20,[22][23][24][25], broad ion beam SEM (BIB-SEM) [21,27,29], and focused ion beam SEM (FIB-SEM) [26][27][28][29][30][31]41], are commonly used in the field of visualized characterization of nanoscale pore systems of tight reservoir rocks such as gas shales and fine-grained sandstones due to their high resolution imaging advantages.…”

Section: Introductionmentioning

confidence: 99%

Nanoscale Pore Structure Characterization and Permeability of Mudrocks and Fine-Grained Sandstones in Coal Reservoirs by Scanning Electron Microscopy, Mercury Intrusion Porosimetry, and Low-Field Nuclear Magnetic Resonance

et al. 2018

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Porosity and permeability of two typical sedimentary rocks in coal bearing strata of underground coal mines in China, i.e., mudrocks and fine-grained sandstones, were comprehensively investigated by multiple experimental methods. Measured porosity averages of the helium gas porosity ( ), MIP porosity ( MIP ), water porosity ( ), and NMR porosity ( NMR ) of the twelve investigated rock samples range from 1.78 to 16.50% and the measured gas permeabilities ( ) range from 0.0003 to 2.4133 mD. Meanwhile, pore types, pore morphologies, and pore size distributions (PSD) were determined by focused ion beam scanning electron microscopy (FIB-SEM), mercury intrusion porosimetry (MIP), and low-field nuclear magnetic resonance (NMR). FIB-SEM image analyses showed that the mineral matrix pores including interparticle (interP) and intraparticle (intraP) pores with varied morphologies are the dominant pore types of the investigated rock samples while very few organic matter (OM) pores were observed. Results of the MIP and the full water-saturated NMR measurements showed that the PSD curves of the mudrock samples mostly present a unimodal pattern and nanopores with pore diameter less than 0.1 m are their predominant pore type, while the PSD curves of the fine-grained sandstone samples are featured by a bimodal distribution. Furthermore, comparison of the full water-saturated and irreducible-water-saturated NMR measurements indicated that pores in the mudrocks are solely adsorption pores (normally pore size < 0.1 m) whereas apart from a fraction of adsorption pores, a large part of the pores in the sandstone sample with relatively high porosity are seepage pores (normally pore size > 0.1 m). Moreover, the PSD curves of NMR quantitatively converted from the NMR 2 spectra by 2 and weighted arithmetic mean (WAM) methods are in good agreement with the PSD curves of MIP. Finally, the applicability of three classic permeability estimation models based on MIP and NMR data to the investigated rock samples was evaluated.

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Pore geometry of sandstone derived from pulsed field gradient NMR

Cited by 66 publications

References 27 publications

Hydraulic characterisation of iron oxide-coated sand and gravel based on nuclear magnetic resonance relaxation modes analyses

Hydraulic characterisation of iron oxide-coated sand and gravel based on nuclear magnetic resonance relaxation modes analyses

Permeability in Rotliegend gas sandstones to gas and brine as predicted from NMR, mercury injection and image analysis

Nanoscale Pore Structure Characterization and Permeability of Mudrocks and Fine-Grained Sandstones in Coal Reservoirs by Scanning Electron Microscopy, Mercury Intrusion Porosimetry, and Low-Field Nuclear Magnetic Resonance

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