Sensitivity and resolution of two-dimensional NMR diffusion-relaxation measurements

Kausik, Ravinath; Hürlimann, Martin D.

doi:10.1016/j.jmr.2016.06.010

Cited by 15 publications

(4 citation statements)

References 29 publications

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“…The peak in the upper edge of the maps is an artifact of 2D‐ILT due to insufficient sampling of higher gradients. To confirm the location of the main peak in the 2D distribution, a single line of data was extracted in each dimension to produce a 1D spectrum of diffusion and relaxation as the 1D ILT is numerically more stable than the 2D (Kausik & Hurlimann, ). As expected, bulk water is characterized by D water = 2.4 × 10 −9 m 2 /s with a reasonably narrow distribution width and by an average T 2 of 2.6 s. Compared to free water, the presence of biofilm_1 produces a significant shift of a portion of the signal to smaller D and lower T 2 .…”

Section: Resultsmentioning

confidence: 99%

NMR investigation of water diffusion in different biofilm structures

Herrling

Weisbrodt

Kirkland

et al. 2017

Biotech & Bioengineering

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Mass transfer in biofilms is determined by diffusion. Different mostly invasive approaches have been used to measure diffusion coefficients in biofilms, however, data on heterogeneous biomass under realistic conditions is still missing. To non-invasively elucidate fluid-structure interactions in complex multispecies biofilms pulsed field gradient-nuclear magnetic resonance (PFG-NMR) was applied to measure the water diffusion in five different types of biomass aggregates: one type of sludge flocs, two types of biofilm, and two types of granules. Data analysis is an important issue when measuring heterogeneous systems and is shown to significantly influence the interpretation and understanding of water diffusion. With respect to numerical reproducibility and physico-chemical interpretation, different data processing methods were explored: (bi)-exponential data analysis and the Γ distribution model. Furthermore, the diffusion coefficient distribution in relation to relaxation was studied by D-T maps obtained by 2D inverse Laplace transform (2D ILT). The results show that the effective diffusion coefficients for all biofilm samples ranged from 0.36 to 0.96 relative to that of water. NMR diffusion was linked to biofilm structure (e.g., biomass density, organic and inorganic matter) as observed by magnetic resonance imaging and to traditional biofilm parameters: diffusion was most restricted in granules with compact structures, and fast diffusion was found in heterotrophic biofilms with fluffy structures. The effective diffusion coefficients in the biomass were found to be broadly distributed because of internal biomass heterogeneities, such as gas bubbles, precipitates, and locally changing biofilm densities. Thus, estimations based on biofilm bulk properties in multispecies systems can be overestimated and mean diffusion coefficients might not be sufficiently informative to describe mass transport in biofilms and the near bulk.

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Section: Resultsmentioning

confidence: 99%

NMR investigation of water diffusion in different biofilm structures

Herrling

Weisbrodt

Kirkland

et al. 2017

Biotech & Bioengineering

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“…In fact, since the relaxation rates of fluids and solids are significantly different, and solid NMR signal is more clearly captured in high field, it is nearly impossible to acquire the whole range of effective signal by an identical device. In other words, low-field NMR technologies are very likely to set a "blind zone" for rock composition analysis (Mehana and Elmonier 2016;Kausik and Hürlimann 2016). Recently, several reports have discussed the method of high-field T 1 -T 2 maps for separating signals of solid components (Papaioannou and Kausik 2015; Song and Kausik 2019), but they are isolated from cores.…”

Section: Petrophysical Property Characterizationmentioning

confidence: 99%

Advances in low-field nuclear magnetic resonance (NMR) technologies applied for characterization of pore space inside rocks: a critical review

et al. 2020

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NMR serves as an important technique for probing rock pore space, such as pore structure characterization, fluid identification, and petrophysical property testing, due to the reusability of cores, convenience in sample processing, and time efficiency in laboratory tests. In practice, NMR signal collection is normally achieved through polarized nuclei relaxation which releases crucial relaxation messages for result interpretation. The impetus of this work is to help engineers and researchers with petroleum background obtain new insights into NMR principals and extend existing methodologies for characterization of unconventional formations. This article first gives a brief description of the development history of relaxation theories and models for porous media. Then, the widely used NMR techniques for characterizing petrophysical properties and pore structures are presented. Meanwhile, limitations and deficiencies of them are summarized. Finally, future work on improving these insufficiencies and approaches of enhancement applicability for NMR technologies are discussed.

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“…However, NMR logging while drilling (NMR-LWD) tools, which started appearing in the oil/gas industry in the early 2000s [ 89 , 90 , 91 , 92 , 93 , 94 ], could determine and identify different fluid phases and their dynamics in geological formations in real-time, while drilling, thus saving time and reducing the cost in a drilling operation. NMR-LWD is rapidly becoming an important logging tool in the oil/gas industry [ 95 ] and more recent works on NMR [ 96 , 97 , 98 , 99 , 100 , 101 , 102 , 103 ] continue to drive advancements in NMR-LWD tools to provide more accurate and better characterization of geological formations [ 104 , 105 , 106 , 107 , 108 , 109 ].…”

Section: Nuclear Magnetic Resonance (Nmr)mentioning

confidence: 99%

Downhole Applications of Magnetic Sensors

Gooneratne

Moellendick

2017

Sensors

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In this paper we present a review of the application of two types of magnetic sensors—fluxgate magnetometers and nuclear magnetic resonance (NMR) sensors—in the oil/gas industry. These magnetic sensors play a critical role in drilling wells safely, accurately and efficiently into a target reservoir zone by providing directional data of the well and acquiring information about the surrounding geological formations. Research into magnetic sensors for oil/gas drilling has not been explored by researchers to the same extent as other applications, such as biomedical, magnetic storage and automotive/aerospace applications. Therefore, this paper aims to serve as an opportunity for researchers to truly understand how magnetic sensors can be used in a downhole environment and to provide fertile ground for research and development in this area. A look ahead, discussing other magnetic sensor technologies that can potentially be used in the oil/gas industry is presented, and what is still needed in order deploy them in the field is also addressed.

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Sensitivity and resolution of two-dimensional NMR diffusion-relaxation measurements

Cited by 15 publications

References 29 publications

NMR investigation of water diffusion in different biofilm structures

NMR investigation of water diffusion in different biofilm structures

Advances in low-field nuclear magnetic resonance (NMR) technologies applied for characterization of pore space inside rocks: a critical review

Downhole Applications of Magnetic Sensors

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