Random-walk technique for simulating NMR measurements and 2D NMR maps of porous media with relaxing and permeable boundaries

Toumelin, Emmanuel; Torres‐Verdín, Carlos; Sun, Bin; Dunn, Keh‐Jim

doi:10.1016/j.jmr.2007.05.024

Cited by 75 publications

(32 citation statements)

References 30 publications

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“…The transverse R 2 -relaxation of spins diffusing in a restricted environment is enhanced by several relaxation contributions [4,[8][9][10][11][12][13][14][15][16][17]19,21,[26][27][28]. In foam, when no external gradients are applied and the B 0 -field is uniform, three contributions are important: R 2b (b for bulk), the intrinsic relaxation rate in the gel matrix, the surface relaxation R 2S , caused by collisions of diffusing spins with the boundaries of the air bubbles, and R 2IG , the relaxation caused by internal gradients that originate from differences in magnetic susceptibility (v) between the gel and the gas phase.…”

Section: Methodsmentioning

confidence: 99%

“…A random walk simulation [6,[24][25][26][27][28] is used to study the relation between the mean air bubble radii and the R 2 -dispersion curve (R 2 as a function of echo time spacing DTE). The effect of other composition-related parameters such as magnetic susceptibility differences, water diffusion coefficient and surface relaxivity has also been investigated.…”

Section: H Mrimentioning

confidence: 99%

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Microstructural analysis of foam by use of NMR R2 dispersion

Baete

Deene

Masschaele

et al. 2008

Journal of Magnetic Resonance

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Section: Methodsmentioning

confidence: 99%

Section: H Mrimentioning

confidence: 99%

Microstructural analysis of foam by use of NMR R2 dispersion

Baete

Deene

Masschaele

et al. 2008

Journal of Magnetic Resonance

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“…Based on NMR theory of fl uid-saturated porous media, when a rock is saturated by a single phase fluid, the transverse relaxation rate 1/T 2 is composed of three parts: bulk, surface, and enhanced diffusion relaxation rates (Richard, 1994;Yun, et al 2002;Toumelin, et al 2007):…”

Section: Simulation Methodsmentioning

confidence: 99%

Numerical simulation of rock pore-throat structure effects on NMR T2 distribution

Wang

2008

Appl. Geophys.

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We built a three-dimensional irregular network model which can adequately describe reservoir rock pore-throat structures. We carried out numerical simulations to study the NMR T 2 distribution of water-saturated rocks. The results indicate that there is a good correlation between T 2 distribution and the pore radius frequency histogram. The total T 2 distribution can be partitioned into pore body and pore throat parts. The effect of parameters including throat radius, pore-throat ratio, and coordination number of the micropore structure on the T 2 distribution can be evaluated individually. The result indicates that: 1) with the increase of the pore throat radius, the T 2 distribution moves toward longer relaxation times and its peak intensity increases; 2) with the increase of the pore-throat ratio, the T 2 distribution moves towards longer T 2 with the peak intensity increasing and the overlap between pore body T 2 and pore throat T 2 decreasing; 3) With the increase of connectivity, the short T 2 component increases and peak signal intensity decreases slightly.

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“…(Hidajat et al, 2003;Ramakrishnan et al, 1999;Talabi, 2008;Vivek and Hirasaki, 2007). 그러나 최근 들어 외부 자기장구배뿐만 아니라 더불어 내부 자기장구배까 지 고려한 시뮬레이션 연구가 수행되되고 있다 (Arns et al, 2011;Mohnke et al, 2011;Toumelin, 2002;Toumelin et al, 2004aToumelin et al, , b, 2006Toumelin et al, , 2007 …”

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A Review on Nuclear Magnetic Resonance Logging: Simulation Schemes

Jang¹,

Nam²

2013

Geophysics and Geophysical Exploration

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Nuclear magnetic resonance (NMR) logging has become an important technique for formation evaluation, detecting interaction signals between H protons and applied magnetic fields. Measured decay signals called relaxation, contain important information about density of H protons and different decay rate due to its fluid type in the sensitive area. Thus, petrophysical information such as porosity, permeability and wettability can be estimated through the interpretation of the decay signals. Many researches on random walk simulation have been published, since a simulation method based on random walk for solving exponential decays was adapted in the early of 1950. This study first makes a review on NMR simulation researches, explains two most important methods: simulation with or without considering magnetic field gradient. Lastly, the study makes a comparison between NMR simulation responses with and without magnetic field gradient to show the importance to consider magnetic gradient to analyze the effects of magnetic gradients on NMR responses.

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Random-walk technique for simulating NMR measurements and 2D NMR maps of porous media with relaxing and permeable boundaries

Cited by 75 publications

References 30 publications

Microstructural analysis of foam by use of NMR R2 dispersion

Microstructural analysis of foam by use of NMR R2 dispersion

Numerical simulation of rock pore-throat structure effects on NMR T2 distribution

A Review on Nuclear Magnetic Resonance Logging: Simulation Schemes

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