NMR relaxometry and diffusometry in characterizing structural, interfacial and colloidal properties of heavy oils and oil sands

Jones, Michael B.; Taylor, Spencer E.

doi:10.1016/j.cis.2015.07.007

Cited by 26 publications

(10 citation statements)

References 90 publications

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“…High values of 1/T2 are quite consistent with previous studies [34,35]. According to the literature regarding to surface relaxivity, the relaxivity was used to investigate structural, interfacial, and colloidal properties of heavy oils and oil sands [37]. The low-field relaxometry was also used to estimate the viscosity and API gravity of Brazil crude oil [24].…”

Section: Discussionsupporting

confidence: 79%

Proton $T_1$ and $T_2$ Relaxivities for $CH_2$ and $CH_3$ Peaks in Crude Oil Measured by 400 MHz NMR

Arsel

Kal

Yılmaz

2021

Journal of Engineering Technology and Applied Sciences

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Petroleum fluid has been extensively studied at low magnetic fields by Nuclear Magnetic Resonance (NMR) Spectroscopy, but high field NMR studies are rarely found in this area. The aim of this study is to determine the proton spin-lattice relaxation rate (1/T 1 ), T 1 relaxivity (R 1 ), proton spin-spin relaxation rate (1/T 2 ) and T 2 relaxivity (R 2 ) of paraffinic CH 2 and gamma CH 3 peaks. For this purpose, crude oil samples were taken from 3 separate wells in the Batman region. Using these samples, 3 different sets were prepared from a mixture of deuterated chloroform (CDCl 3 ) and crude oil. The total volume of each prepared mixture was 1 mL. The crude oil content in each set was changed from 0.05 mL to 0.20 mL in 0.05 mL steps.. Special care has been taken to ensure the best shimming of the NMR spectrometer operating at 400 MHz. T 1 measurements were performed using an inversion recovery (IR) pulse sequence. 1/T 2 values were determined from the half-height line widths of CH 2 and CH 3 peaks. 1/T 1 and 1/T 2 rates and all relaxivities were found to vary from well to well. This change is due to the fluid composition of the wells. The 1/T 2 rates and R 2 relaxivities were found to be considerably greater than the 1/T 1 rates and R 1 relaxivities. R 2 relaxivities for CH 3 were also 2-5 times greater than for CH 2 .The higher 1/T 2 and R 2 relaxivities compared with 1/T 1 and R 1 were attributed to the additional CDCl 3mediated relaxation mechanisms. In conclusion, available data show that high 1/T 2 rates and R 2 relaxivities measured in the high field NMR laboratory can be applied to separate crude oil from other fluids in the oil field.

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Section: Discussionsupporting

confidence: 79%

Proton $T_1$ and $T_2$ Relaxivities for $CH_2$ and $CH_3$ Peaks in Crude Oil Measured by 400 MHz NMR

Arsel

Kal

Yılmaz

2021

Journal of Engineering Technology and Applied Sciences

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“…Among its many attributes, 1 H nuclear magnetic resonance (NMR) relaxation is a versatile nondestructive technique for measuring crude oil viscosity and composition, thus providing a unique contribution to the characterization of light crude oils, heavy crude oils, and bitumen. − However, the 1 H NMR relaxation mechanism in crude oils at high viscosity such as heavy oils and bitumen remains elusive and a topic of great debate.…”

Section: Introductionmentioning

confidence: 99%

Elucidating the ¹H NMR Relaxation Mechanism in Polydisperse Polymers and Bitumen Using Measurements, MD Simulations, and Models

et al. 2020

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The mechanism behind the 1 H nuclear magnetic resonance (NMR) frequency dependence of T 1 and the viscosity dependence of T 2 for polydisperse polymers and bitumen remains elusive. We elucidate the matter through NMR relaxation measurements of polydisperse polymers over an extended range of frequencies ( f 0 = 0.01−400 MHz) and viscosities (η = 385−102 000 cP) using T 1 and T 2 in static fields, T 1 field-cycling relaxometry, and T 1ρ in the rotating frame. We account for the anomalous behavior of the log-mean relaxation times T 1LM ∝ f 0 and T 2LM ∝ (η/T) −1/2 with a phenomenological model of 1 H− 1 H dipole−dipole relaxation, which includes a distribution in molecular correlation times and internal motions of the nonrigid polymer branches. We show that the model also accounts for the anomalous T 1LM and T 2LM in previously reported bitumen measurements. We find that molecular dynamics (MD) simulations of the T 1 ∝ f 0 dispersion and T 2 of similar polymers simulated over a range of viscosities (η = 1−1000 cP) are in good agreement with measurements and the model. The T 1 ∝ f 0 dispersion at high viscosities agrees with previously reported MD simulations of heptane confined in a polymer matrix, which suggests a common NMR relaxation mechanism between viscous polydisperse fluids and fluids under nanoconfinement, without the need to invoke paramagnetism.

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“…Although previous DLS studies of model asphaltenes succeeded in identifying critical concentrations, solvent reactivity, and the impact of functional group percentages on the aggregation of asphaltenes, , the results are usually highly dependent on the exact nature of the samples, , from which a generic mechanism is hard to conclude. Diffusion nuclear magnetic resonance (NMR) technique, also known as diffusion-ordered spectroscopy (DOSY), , is another technique previously used to study asphaltene aggregation. − The diffusion coefficients of signals originating from different species are separated in a two-dimensional NMR spectrum, allowing for the identification of different species in the sample on the basis of both chemistry and size.…”

Section: Introductionmentioning

confidence: 99%

“…Diffusion nuclear magnetic resonance (NMR) technique, also known as diffusion-ordered spectroscopy (DOSY), 40,41 is another technique previously used to study asphaltenes aggregation. [42][43][44][45][46][47][48] The diffusion coefficients of signals originating from different species are separated in a 2-dimensional NMR spectrum, allowing for the identification of different species in the sample on the basis of both chemistry and size.…”

mentioning

confidence: 99%

Combined Experimental and Computational Study of Polyaromatic Hydrocarbon Aggregation: Isolating the Effect of Attached Functional Groups

Simionesie

O’Callaghan

Laurent

et al. 2019

Ind. Eng. Chem. Res.

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To establish, and isolate, the influence of different chemical functional groups on the aggregation of polyaromatic hydrocarbons, a series of triphenylene-based compounds were investigated using experimental and computational approaches together. Containing alkoxy-side chains of varying length and amide appendages, both with and without a terminating carboxylic acid, their aggregation structures, sizes, and kinetics in toluene were studied over several length scales, using a combination of Dynamic Light Scattering (DLS) and Diffusion-Ordered NMR spectroscopy (DOSY), complemented with Molecular Dynamics (MD) simulations. There is a strong correlation between molecular architecture and aggregation mechanisms across different length scales: addition of polar functional groups and heteroatoms resulted in compounds that are more prone to aggregation and form large, micrometer-sized clusters, while the increased steric hindrance imposed by alkoxy-side chains led to stable nanometer-sized aggregates. These conclusions underline the strong structurefunction relationship of polyaromatic hydrocarbons, such as asphaltenes, examined here over multiple size-scales in a single solvent. We also demonstrated the importance of using complementary techniques to study the aggregation process of polyaromatic hydrocarbons that could form aggregates of various sizes over different timescales.

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NMR relaxometry and diffusometry in characterizing structural, interfacial and colloidal properties of heavy oils and oil sands

Cited by 26 publications

References 90 publications

Proton $T_1$ and $T_2$ Relaxivities for $CH_2$ and $CH_3$ Peaks in Crude Oil Measured by 400 MHz NMR

Proton $T_1$ and $T_2$ Relaxivities for $CH_2$ and $CH_3$ Peaks in Crude Oil Measured by 400 MHz NMR

Elucidating the ¹H NMR Relaxation Mechanism in Polydisperse Polymers and Bitumen Using Measurements, MD Simulations, and Models

Combined Experimental and Computational Study of Polyaromatic Hydrocarbon Aggregation: Isolating the Effect of Attached Functional Groups

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NMR relaxometry and diffusometry in characterizing structural, interfacial and colloidal properties of heavy oils and oil sands

Cited by 26 publications

References 90 publications

Proton $T_1$ and $T_2$ Relaxivities for $CH_2$ and $CH_3$ Peaks in Crude Oil Measured by 400 MHz NMR

Proton $T_1$ and $T_2$ Relaxivities for $CH_2$ and $CH_3$ Peaks in Crude Oil Measured by 400 MHz NMR

Elucidating the 1H NMR Relaxation Mechanism in Polydisperse Polymers and Bitumen Using Measurements, MD Simulations, and Models

Combined Experimental and Computational Study of Polyaromatic Hydrocarbon Aggregation: Isolating the Effect of Attached Functional Groups

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Elucidating the ¹H NMR Relaxation Mechanism in Polydisperse Polymers and Bitumen Using Measurements, MD Simulations, and Models