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Enjilela R, Guo J, MacMillan B, Marica F, Afrough A, Balcom B. T 1-T 2* relaxation correlation measurements. JOURNAL OF MAGNETIC RESONANCE (SAN DIEGO, CALIF. : 1997) 2021; 326:106961. [PMID: 33744831 DOI: 10.1016/j.jmr.2021.106961] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/03/2019] [Revised: 11/17/2020] [Accepted: 02/28/2021] [Indexed: 06/12/2023]
Abstract
The majority of low field Magnetic Resonance (MR) analyses rely on T2 lifetime measurements. Modification of the T2 measurement to include a T1 dimension has made the T1-T2 measurement a very powerful analytical technique. The T1-T2 measurement is uniquely well suited to characterization of different spin populations in porous materials, such as fluid bearing reservoir rocks, and in soft biopolymer materials, for example foods. However, the T1-T2 measurement is challenging or impossible if the T2 relaxation lifetime, or a component lifetime, is short-lived and the signal unobservable in an echo measurement. This occurs in many important classes of materials. A short lifetime T2 will not however, in general, preclude observation of a free induction decay with signal decay governed by T2*. As outlined in this paper a T1-T2* measurement is a useful analog to the T1-T2 experiment. T1-T2* measurement enables one to differentiate species as a function of T2* in one dimension and T1 in the other dimension. Monitoring changes of the T1-T2* coordinate, and associated signal intensity changes, has the potential to reveal structural changes in materials evolving in time. These methods may also be employed to discriminate and identify solid-like species present in static samples. The T1-T2* measurement is very general in application, but in this paper we focus on cement-based mortars to develop and illustrate the essential ideas. T1-T2* results show a multi-modal behaviour of the MR signal lifetimes, T1 and T2*, in mortar samples under study, indicating at least two different water populations. The short T2* lifetime was assigned to interlayer water (water between C-S-H layers) where the associated T1 is also short lived. The longer T2* lifetime was assigned to water in the pore space, where T1 is also longer lived. In addition to mortar samples we also show application of the method to a crystalline organic species, o-phenylenediamine, which features Sinc Gaussian and exponential decays of transverse magnetization.
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Affiliation(s)
- Razieh Enjilela
- UNB MRI Centre, Department of Physics, University of New Brunswick, Fredericton, New Brunswick E3B 5A3, Canada.
| | - Jiangfeng Guo
- UNB MRI Centre, Department of Physics, University of New Brunswick, Fredericton, New Brunswick E3B 5A3, Canada.
| | - Bryce MacMillan
- UNB MRI Centre, Department of Physics, University of New Brunswick, Fredericton, New Brunswick E3B 5A3, Canada.
| | - Florea Marica
- UNB MRI Centre, Department of Physics, University of New Brunswick, Fredericton, New Brunswick E3B 5A3, Canada.
| | - Armin Afrough
- UNB MRI Centre, Department of Physics, University of New Brunswick, Fredericton, New Brunswick E3B 5A3, Canada.
| | - Bruce Balcom
- UNB MRI Centre, Department of Physics, University of New Brunswick, Fredericton, New Brunswick E3B 5A3, Canada.
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2
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El Abd A, Taman M, Zhao Y. A new method for measurement of moisture transport in porous media based on forward and backward scattering of epithermal neutrons. Appl Radiat Isot 2021; 173:109730. [PMID: 33894468 DOI: 10.1016/j.apradiso.2021.109730] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2020] [Revised: 03/17/2021] [Accepted: 04/08/2021] [Indexed: 11/26/2022]
Abstract
We present a new method for determining the spatial distribution and transport of water in porous media. It is based on the detection of both forward and backward scattered neutrons from the wet regions of the samples under investigation. The experimental set-up is based on a Pu-Be neutron source and He-3 neutron detector assemblies. The results obtained showed that back scattered neutrons are more sensitive than the forward scattered neutrons to determine water content. Moreover, both forward and back scattered neutrons are more sensitive than either back or forward neutrons for determining water content. The method was used to measure moisture transport in sand columns and brick samples. Forward and backward scattered neutrons from different wet regions along the water flow path (x) are recorded as the sample absorbs water. Water saturates the regions of the samples tested near the inlet of water faster than the others. The water front positions were found to follow the square root behavior of the absorption time, and capillary penetration coefficients were determined for the samples investigated. The developed method can be used to investigate water absorption at various flow rates in porous samples of various sizes.
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Affiliation(s)
- A El Abd
- Reactor Physics Department, Nuclear Research Center, Egyptian Atomic Energy Authority, P.O. Box:13759, Inchass, Cairo, Egypt.
| | - M Taman
- Department of Structural Engineering, Faculty of Engineering, Tanta University, 31511, Tanta, Egypt
| | - Yixin Zhao
- Beijing Key Laboratory for Precise Mining of Intergrown Energy and Resources, China University of Mining and Technology (Beijing), Beijing, 100083, China; State Key Laboratory of Coal Resources and Safe Mining, China University of Mining and Technology, Beijing, 100083, PR China; School of Energy & Mining Engineering, China University of Mining and Technology, Beijing, 100083, PR China
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3
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Yarman CE, Mitchell J. A greedy variational approach for generating sparse T 1-T 2 NMR relaxation time distributions. JOURNAL OF MAGNETIC RESONANCE (SAN DIEGO, CALIF. : 1997) 2019; 301:94-101. [PMID: 30861458 DOI: 10.1016/j.jmr.2019.02.009] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/02/2019] [Revised: 02/27/2019] [Accepted: 02/28/2019] [Indexed: 06/09/2023]
Abstract
We present a nonlinear inversion method for generating sparse solutions to the Fredholm Integral equation describing two-dimensional distributions of nuclear magnetic resonance (NMR) relaxation times or diffusion coefficients. Our greedy variational method approximates the distribution of exponential rate constants using a sum of Dirac delta functions, which constitute our dictionary elements. The greedy nature of the method promotes sparsity in the representation by iteratively increasing the number of terms. The variational component estimates the parameters of the Dirac delta functions from a continuum at each iteration by reducing the least squares misfit to the data. Unlike sparsity promoting linearized inversion methods, where the dictionary is fixed and can exponentially grow in the case of multiple variables or when searching for higher resolution, the greedy component of our method aims to keep the dictionary small while the variational component keeps the dictionary dynamic. We demonstrate our method with synthetic data and experimental measurements of T1-T2 correlations of liquid-saturated porous rocks. The sparsity of the approximate solutions is ideal for real-time processing and transmission in remote or mobile NMR applications such as well logging.
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Affiliation(s)
- Can Evren Yarman
- Schlumberger Cambridge Research, High Cross, Madingley Road, Cambridge CB3 0EL, UK.
| | - Jonathan Mitchell
- Schlumberger Cambridge Research, High Cross, Madingley Road, Cambridge CB3 0EL, UK
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Terenzi C, Sederman AJ, Mantle MD, Gladden LF. Spatially-resolved 1H NMR relaxation-exchange measurements in heterogeneous media. JOURNAL OF MAGNETIC RESONANCE (SAN DIEGO, CALIF. : 1997) 2019; 299:101-108. [PMID: 30593999 DOI: 10.1016/j.jmr.2018.12.010] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/29/2018] [Revised: 12/07/2018] [Accepted: 12/13/2018] [Indexed: 06/09/2023]
Abstract
In the last decades, the 1H NMR T2-T2 relaxation-exchange (REXSY) technique has become an essential tool for the molecular investigation of simple and complex fluids in heterogeneous porous solids and soft matter, where the mixing-time-evolution of cross-correlated T2-T2 peaks enables a quantitative study of diffusive exchange kinetics in multi-component systems. Here, we present a spatially-resolved implementation of the T2-T2 correlation technique, named z-T2-T2, based on one-dimensional spatial mapping along z using a rapid frequency-encode imaging scheme. Compared to other phase-encoding methods, the adopted MRI technique has two distinct advantages: (i) is has the same experimental duration of a standard (bulk) T2-T2 measurement, and (ii) it provides a high spatial resolution. The proposed z-T2-T2 method is first validated against bulk T2-T2 measurements on homogeneous phantom consisting of cyclohexane uniformly imbibed in finely-sized α-Al2O3 particles at a spatial resolution of 0.47 mm; thereafter, its performance is demonstrated, on a layered bed of multi-sized α-Al2O3 particles, for revealing spatially-dependent molecular exchange kinetics properties of intra- and inter-particle cyclohexane as a function of particle size. It is found that localised z-T2-T2 spectra provide well resolved cross peaks whilst such resolution is lost in standard bulk T2-T2 data. Future prospective applications of the method lie, in particular, in the local characterisation of mass transport phenomena in multi-component porous media, such as rock cores and heterogeneous catalysts.
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Affiliation(s)
- Camilla Terenzi
- Department of Chemical Engineering and Biotechnology, University of Cambridge, Philippa Fawcett Drive, Cambridge CB3 0AS, UK
| | - Andrew J Sederman
- Department of Chemical Engineering and Biotechnology, University of Cambridge, Philippa Fawcett Drive, Cambridge CB3 0AS, UK
| | - Michael D Mantle
- Department of Chemical Engineering and Biotechnology, University of Cambridge, Philippa Fawcett Drive, Cambridge CB3 0AS, UK.
| | - Lynn F Gladden
- Department of Chemical Engineering and Biotechnology, University of Cambridge, Philippa Fawcett Drive, Cambridge CB3 0AS, UK
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5
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Liu R, Du D, Pu W, Peng Q, Tao Z, Pang Y. Viscoelastic displacement and anomalously enhanced oil recovery of a novel star-like amphiphilic polyacrylamide. Chem Eng Res Des 2019. [DOI: 10.1016/j.cherd.2018.12.021] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
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6
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Fast spatially-resolved T 2 measurements with constant-gradient CPMG. Magn Reson Imaging 2018; 56:70-76. [PMID: 30228017 DOI: 10.1016/j.mri.2018.09.003] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2018] [Accepted: 09/06/2018] [Indexed: 10/28/2022]
Abstract
Speed of acquisition is paramount for the application of magnetic resonance to flow experiments through porous rocks. One popular method for imaging core floods is the spatially resolved T2 experiment which can separate fluids either by their viscosity contrast or by doping one fluid with a relaxation agent. Existing techniques for spatial-T2 may suffer from long acquisition times and eddy currents due to the pulsing of magnetic field gradients. Here, we propose a constant gradient method for 1d spatially-resolved T2 which embraces the speed of frequency encoding techniques and avoids eddy currents by the absence of any gradient ramps during the radio frequency (r.f.) pulse train. We provide the operating envelope for this kind of experiment, which is restricted due to the slice selectivity of the r.f. pulses in the presence of the magnetic field gradient. Additionally, we show that the effects of self-diffusion and the mixing of T1 and T2 contributions are manageable. As an illustration, we have applied this technique to an enhanced oil recovery experiment. The two fluid phases were tracked without any doping and with a time resolution of 40 s. In this case, the increased time resolution allowed us to observe dynamic flow phenomena such as fluid fingering and the calculation of the velocity of the fluid displacement fronts.
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7
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Vashaee S, Li M, Newling B, MacMillan B, Marica F, Kwak HT, Gao J, Al-Harbi AM, Balcom BJ. Local T 1-T 2 distribution measurements in porous media. JOURNAL OF MAGNETIC RESONANCE (SAN DIEGO, CALIF. : 1997) 2018; 287:113-122. [PMID: 29335164 DOI: 10.1016/j.jmr.2018.01.001] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/06/2017] [Revised: 12/18/2017] [Accepted: 01/03/2018] [Indexed: 06/07/2023]
Abstract
A novel slice-selective T1-T2 measurement is proposed to measure spatially resolved T1-T2 distributions. An adiabatic inversion pulse is employed for slice-selection. The slice-selective pulse is able to select a quasi-rectangular slice, on the order of 1 mm, at an arbitrary position within the sample.The method does not employ conventional selective excitation in which selective excitation is often accomplished by rotation of the longitudinal magnetization in the slice of interest into the transverse plane, but rather a subtraction based on CPMG data acquired with and without adiabatic inversion slice selection. T1 weighting is introduced during recovery from the inversion associated with slice selection. The local T1-T2 distributions measured are of similar quality to bulk T1-T2 measurements. The new method can be employed to characterize oil-water mixtures and other fluids in porous media. The method is beneficial when a coarse spatial distribution of the components is of interest.
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Affiliation(s)
- S Vashaee
- UNB MRI Centre, Department of Physics, University of New Brunswick, Fredericton, New Brunswick E3B 5A3, Canada.
| | - M Li
- UNB MRI Centre, Department of Physics, University of New Brunswick, Fredericton, New Brunswick E3B 5A3, Canada.
| | - B Newling
- UNB MRI Centre, Department of Physics, University of New Brunswick, Fredericton, New Brunswick E3B 5A3, Canada.
| | - B MacMillan
- UNB MRI Centre, Department of Physics, University of New Brunswick, Fredericton, New Brunswick E3B 5A3, Canada.
| | - F Marica
- UNB MRI Centre, Department of Physics, University of New Brunswick, Fredericton, New Brunswick E3B 5A3, Canada.
| | - H T Kwak
- Saudi Aramco EXPEC Advanced Research Center, Reservoir Engineering Technology Division, Pore Scale Physics Focus Area, Bldg. 2291, #GA-168, Saudi Arabia.
| | - J Gao
- Saudi Aramco EXPEC Advanced Research Center, Reservoir Engineering Technology Division, Pore Scale Physics Focus Area, Bldg. 2291, #GA-168, Saudi Arabia.
| | - A M Al-Harbi
- Saudi Aramco EXPEC Advanced Research Center, Reservoir Engineering Technology Division, Pore Scale Physics Focus Area, Bldg. 2291, #GA-168, Saudi Arabia.
| | - B J Balcom
- UNB MRI Centre, Department of Physics, University of New Brunswick, Fredericton, New Brunswick E3B 5A3, Canada.
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8
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In Situ Chemically-Selective Monitoring of Multiphase Displacement Processes in a Carbonate Rock Using 3D Magnetic Resonance Imaging. Transp Porous Media 2018; 121:15-35. [PMID: 31983793 PMCID: PMC6954023 DOI: 10.1007/s11242-017-0945-6] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2017] [Accepted: 09/23/2017] [Indexed: 11/24/2022]
Abstract
Accurate monitoring of multiphase displacement processes is essential for the development, validation and benchmarking of numerical models used for reservoir simulation and for asset characterization. Here we demonstrate the first application of a chemically-selective 3D magnetic resonance imaging (MRI) technique which provides high-temporal resolution, quantitative, spatially resolved information of oil and water saturations during a dynamic imbibition core flood experiment in an Estaillades carbonate rock. Firstly, the relative saturations of dodecane (\documentclass[12pt]{minimal}
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\begin{document}$$S_{\mathrm{o}})$$\end{document}So) and water (\documentclass[12pt]{minimal}
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\begin{document}$$S_{\mathrm{w}})$$\end{document}Sw), as determined from the MRI measurements, have been benchmarked against those obtained from nuclear magnetic resonance (NMR) spectroscopy and volumetric analysis of the core flood effluent. Excellent agreement between both the NMR and MRI determinations of \documentclass[12pt]{minimal}
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\begin{document}$$S_{\mathrm{w}}$$\end{document}Sw was obtained. These values were in agreement to 4 and 9% of the values determined by volumetric analysis, with absolute errors in the measurement of saturation determined by NMR and MRI being 0.04 or less over the range of relative saturations investigated. The chemically-selective 3D MRI method was subsequently applied to monitor the displacement of dodecane in the core plug sample by water under continuous flow conditions at an interstitial velocity of \documentclass[12pt]{minimal}
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\begin{document}$$1.27\times 10^{-6}\,\hbox {m}\,\hbox {s}^{-1}$$\end{document}1.27×10-6ms-1 (\documentclass[12pt]{minimal}
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\begin{document}$$0.4\,\hbox {ft}\,\hbox {day}^{-1})$$\end{document}0.4ftday-1). During the core flood, independent images of water and oil distributions within the rock core plug at a spatial resolution of \documentclass[12pt]{minimal}
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\begin{document}$$0.31\,\hbox {mm}\times 0.39\,\hbox {mm} \times 0.39\,\hbox {mm}$$\end{document}0.31mm×0.39mm×0.39mm were acquired on a timescale of 16 min per image. Using this technique the spatial and temporal dynamics of the displacement process have been monitored. This MRI technique will provide insights to structure–transport relationships associated with multiphase displacement processes in complex porous materials, such as those encountered in petrophysics research.
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Ramskill NP, Bush I, Sederman AJ, Mantle MD, Benning M, Anger BC, Appel M, Gladden LF. Fast imaging of laboratory core floods using 3D compressed sensing RARE MRI. JOURNAL OF MAGNETIC RESONANCE (SAN DIEGO, CALIF. : 1997) 2016; 270:187-197. [PMID: 27500742 DOI: 10.1016/j.jmr.2016.07.017] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/16/2016] [Revised: 07/26/2016] [Accepted: 07/27/2016] [Indexed: 06/06/2023]
Abstract
Three-dimensional (3D) imaging of the fluid distributions within the rock is essential to enable the unambiguous interpretation of core flooding data. Magnetic resonance imaging (MRI) has been widely used to image fluid saturation in rock cores; however, conventional acquisition strategies are typically too slow to capture the dynamic nature of the displacement processes that are of interest. Using Compressed Sensing (CS), it is possible to reconstruct a near-perfect image from significantly fewer measurements than was previously thought necessary, and this can result in a significant reduction in the image acquisition times. In the present study, a method using the Rapid Acquisition with Relaxation Enhancement (RARE) pulse sequence with CS to provide 3D images of the fluid saturation in rock core samples during laboratory core floods is demonstrated. An objective method using image quality metrics for the determination of the most suitable regularisation functional to be used in the CS reconstructions is reported. It is shown that for the present application, Total Variation outperforms the Haar and Daubechies3 wavelet families in terms of the agreement of their respective CS reconstructions with a fully-sampled reference image. Using the CS-RARE approach, 3D images of the fluid saturation in the rock core have been acquired in 16min. The CS-RARE technique has been applied to image the residual water saturation in the rock during a water-water displacement core flood. With a flow rate corresponding to an interstitial velocity of vi=1.89±0.03ftday(-1), 0.1 pore volumes were injected over the course of each image acquisition, a four-fold reduction when compared to a fully-sampled RARE acquisition. Finally, the 3D CS-RARE technique has been used to image the drainage of dodecane into the water-saturated rock in which the dynamics of the coalescence of discrete clusters of the non-wetting phase are clearly observed. The enhancement in the temporal resolution that has been achieved using the CS-RARE approach enables dynamic transport processes pertinent to laboratory core floods to be investigated in 3D on a time-scale and with a spatial resolution that, until now, has not been possible.
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Affiliation(s)
- N P Ramskill
- Department of Chemical Engineering and Biotechnology, University of Cambridge, Pembroke Street, Cambridge CB2 3RA, UK.
| | - I Bush
- Department of Chemical Engineering and Biotechnology, University of Cambridge, Pembroke Street, Cambridge CB2 3RA, UK
| | - A J Sederman
- Department of Chemical Engineering and Biotechnology, University of Cambridge, Pembroke Street, Cambridge CB2 3RA, UK
| | - M D Mantle
- Department of Chemical Engineering and Biotechnology, University of Cambridge, Pembroke Street, Cambridge CB2 3RA, UK
| | - M Benning
- Department of Applied Mathematics and Theoretical Physics, University of Cambridge, Wilberforce Road, Cambridge CB3 0WA, UK
| | - B C Anger
- Shell Technology Centre, 3333 Highway 6 S, Houston, TX, USA
| | - M Appel
- Shell Technology Centre, 3333 Highway 6 S, Houston, TX, USA
| | - L F Gladden
- Department of Chemical Engineering and Biotechnology, University of Cambridge, Pembroke Street, Cambridge CB2 3RA, UK
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Kausik R, Hürlimann MD. Sensitivity and resolution of two-dimensional NMR diffusion-relaxation measurements. JOURNAL OF MAGNETIC RESONANCE (SAN DIEGO, CALIF. : 1997) 2016; 270:12-23. [PMID: 27389638 DOI: 10.1016/j.jmr.2016.06.010] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/10/2016] [Revised: 06/14/2016] [Accepted: 06/15/2016] [Indexed: 06/06/2023]
Abstract
The performance of 2D NMR diffusion-relaxation measurements for fluid typing applications is analyzed. In particular, we delineate the region in the diffusion - relaxation plane that can be determined with a given gradient strength and homogeneity, and compare the performance of the single and double echo encoding with the stimulated echo diffusion encoding. We show that the diffusion editing based approach is able to determine the diffusion coefficient only if the relaxation time T2 exceeds a cutoff value T2,cutoff, that scales like T2,cutoff∝g(-2/3)D(-1/3). For stimulated echo encoding, the optimal diffusion encoding times (Td and δ), that provide the best diffusion sensitivity, rely only on the T1/T2 ratios and not on the diffusion coefficients of the fluids or the applied gradient strengths. Irrespective of T1, for high enough gradients (i.e. when γ(2)g(2)DT2(3)>10(2)), the Hahn echo based encoding is superior to encoding based on the stimulated echo. For weaker gradients, the stimulated echo is superior only if the T1/T2 ratio is much larger than 1. For single component systems, the diffusion sensitivity is not adversely impacted by the uniformity of the gradients and the diffusion distributions can be well measured. The presence of non-uniform gradients can affect the determination of the diffusion distributions when you have two fluids of comparable T2. In such situations the effective single component diffusion coefficient is always closer to the geometric mean diffusion coefficient of the two fluids.
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11
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Li M, Xiao D, Romero-Zerón L, Balcom BJ. Monitoring oil displacement processes with k-t accelerated spin echo SPI. MAGNETIC RESONANCE IN CHEMISTRY : MRC 2016; 54:197-204. [PMID: 26626141 DOI: 10.1002/mrc.4362] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/17/2015] [Revised: 08/31/2015] [Accepted: 09/03/2015] [Indexed: 06/05/2023]
Abstract
Magnetic resonance imaging (MRI) is a robust tool to monitor oil displacement processes in porous media. Conventional MRI measurement times can be lengthy, which hinders monitoring time-dependent displacements. Knowledge of the oil and water microscopic distribution is important because their pore scale behavior reflects the oil trapping mechanisms. The oil and water pore scale distribution is reflected in the magnetic resonance T2 signal lifetime distribution. In this work, a pure phase-encoding MRI technique, spin echo SPI (SE-SPI), was employed to monitor oil displacement during water flooding and polymer flooding. A k-t acceleration method, with low-rank matrix completion, was employed to improve the temporal resolution of the SE-SPI MRI measurements. Comparison to conventional SE-SPI T2 mapping measurements revealed that the k-t accelerated measurement was more sensitive and provided higher-quality results. It was demonstrated that the k-t acceleration decreased the average measurement time from 66.7 to 20.3 min in this work. A perfluorinated oil, containing no (1) H, and H2 O brine were employed to distinguish oil and water phases in model flooding experiments. High-quality 1D water saturation profiles were acquired from the k-t accelerated SE-SPI measurements. Spatially and temporally resolved T2 distributions were extracted from the profile data. The shift in the (1) H T2 distribution of water in the pore space to longer lifetimes during water flooding and polymer flooding is consistent with increased water content in the pore space. Copyright © 2015 John Wiley & Sons, Ltd.
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Affiliation(s)
- Ming Li
- MRI Center, Department of Physics, University of New Brunswick, PO Box 4400, Fredericton, NB, E3B 5A3, Canada
- Department of Chemical Engineering, University of New Brunswick, PO Box 4400, Fredericton, NB, E3B 5A3, Canada
| | - Dan Xiao
- MRI Center, Department of Physics, University of New Brunswick, PO Box 4400, Fredericton, NB, E3B 5A3, Canada
| | - Laura Romero-Zerón
- Department of Chemical Engineering, University of New Brunswick, PO Box 4400, Fredericton, NB, E3B 5A3, Canada
| | - Bruce J Balcom
- MRI Center, Department of Physics, University of New Brunswick, PO Box 4400, Fredericton, NB, E3B 5A3, Canada
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12
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Mitchell J, Howe AM, Clarke A. Real-time oil-saturation monitoring in rock cores with low-field NMR. JOURNAL OF MAGNETIC RESONANCE (SAN DIEGO, CALIF. : 1997) 2015; 256:34-42. [PMID: 25996514 DOI: 10.1016/j.jmr.2015.04.011] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/24/2015] [Revised: 04/21/2015] [Accepted: 04/22/2015] [Indexed: 06/04/2023]
Abstract
Nuclear magnetic resonance (NMR) provides a powerful suite of tools for studying oil in reservoir core plugs at the laboratory scale. Low-field magnets are preferred for well-log calibration and to minimize magnetic-susceptibility-induced internal gradients in the porous medium. We demonstrate that careful data processing, combined with prior knowledge of the sample properties, enables real-time acquisition and interpretation of saturation state (relative amount of oil and water in the pores of a rock). Robust discrimination of oil and brine is achieved with diffusion weighting. We use this real-time analysis to monitor the forced displacement of oil from porous materials (sintered glass beads and sandstones) and to generate capillary desaturation curves. The real-time output enables in situ modification of the flood protocol and accurate control of the saturation state prior to the acquisition of standard NMR core analysis data, such as diffusion-relaxation correlations. Although applications to oil recovery and core analysis are demonstrated, the implementation highlights the general practicality of low-field NMR as an inline sensor for real-time industrial process control.
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Affiliation(s)
- J Mitchell
- Schlumberger Gould Research, High Cross, Madingley Road, Cambridge CB3 0EL, UK.
| | - A M Howe
- Schlumberger Gould Research, High Cross, Madingley Road, Cambridge CB3 0EL, UK
| | - A Clarke
- Schlumberger Gould Research, High Cross, Madingley Road, Cambridge CB3 0EL, UK
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13
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Yang W, Zhang L, Liu Y, Zhao Y, Jiang L, Yang M, Wang Z, Wang D, Song Y. Dynamic stability characteristics of fluid flow in CO2 miscible displacements in porous media. RSC Adv 2015. [DOI: 10.1039/c5ra01877c] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
The dynamic stability characteristics of fluid flow in miscible displacement processes were investigated by using a magnetic resonance imaging apparatus and simulated by a lattice-Boltzmann method at elevated pressures.
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Affiliation(s)
- Wenzhe Yang
- Key Laboratory of Ocean Energy Utilization and Energy Conservation of Ministry of Education
- Dalian University of Technology
- Dalian
- China
| | - Liang Zhang
- Key Laboratory of Ocean Energy Utilization and Energy Conservation of Ministry of Education
- Dalian University of Technology
- Dalian
- China
| | - Yu Liu
- Key Laboratory of Ocean Energy Utilization and Energy Conservation of Ministry of Education
- Dalian University of Technology
- Dalian
- China
| | - Yuechao Zhao
- Key Laboratory of Ocean Energy Utilization and Energy Conservation of Ministry of Education
- Dalian University of Technology
- Dalian
- China
| | - Lanlan Jiang
- Key Laboratory of Ocean Energy Utilization and Energy Conservation of Ministry of Education
- Dalian University of Technology
- Dalian
- China
| | - Mingjun Yang
- Key Laboratory of Ocean Energy Utilization and Energy Conservation of Ministry of Education
- Dalian University of Technology
- Dalian
- China
| | - Zhiguo Wang
- Civil Engineering College
- Northeast Petroleum University
- Daqing
- China
| | - Dayong Wang
- Key Laboratory of Ocean Energy Utilization and Energy Conservation of Ministry of Education
- Dalian University of Technology
- Dalian
- China
| | - Yongchen Song
- Key Laboratory of Ocean Energy Utilization and Energy Conservation of Ministry of Education
- Dalian University of Technology
- Dalian
- China
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14
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Mitchell J, Fordham EJ. Contributed review: nuclear magnetic resonance core analysis at 0.3 T. THE REVIEW OF SCIENTIFIC INSTRUMENTS 2014; 85:111502. [PMID: 25430091 DOI: 10.1063/1.4902093] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
Nuclear magnetic resonance (NMR) provides a powerful toolbox for petrophysical characterization of reservoir core plugs and fluids in the laboratory. Previously, there has been considerable focus on low field magnet technology for well log calibration. Now there is renewed interest in the study of reservoir samples using stronger magnets to complement these standard NMR measurements. Here, the capabilities of an imaging magnet with a field strength of 0.3 T (corresponding to 12.9 MHz for proton) are reviewed in the context of reservoir core analysis. Quantitative estimates of porosity (saturation) and pore size distributions are obtained under favorable conditions (e.g., in carbonates), with the added advantage of multidimensional imaging, detection of lower gyromagnetic ratio nuclei, and short probe recovery times that make the system suitable for shale studies. Intermediate field instruments provide quantitative porosity maps of rock plugs that cannot be obtained using high field medical scanners due to the field-dependent susceptibility contrast in the porous medium. Example data are presented that highlight the potential applications of an intermediate field imaging instrument as a complement to low field instruments in core analysis and for materials science studies in general.
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Affiliation(s)
- Jonathan Mitchell
- Schlumberger Gould Research, High Cross, Madingley Road, Cambridge CB3 0EL, United Kingdom
| | - Edmund J Fordham
- Schlumberger Gould Research, High Cross, Madingley Road, Cambridge CB3 0EL, United Kingdom
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15
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Mitchell J. Rapid measurements of heterogeneity in sandstones using low-field nuclear magnetic resonance. JOURNAL OF MAGNETIC RESONANCE (SAN DIEGO, CALIF. : 1997) 2014; 240:52-60. [PMID: 24530953 DOI: 10.1016/j.jmr.2014.01.006] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/05/2013] [Revised: 01/14/2014] [Accepted: 01/17/2014] [Indexed: 06/03/2023]
Abstract
Sandstone rocks can contain microscopic variations in composition that complicate interpretation of nuclear magnetic resonance (NMR) relaxation time measurements. In this work, methods for assessing the degree of sample heterogeneity are demonstrated in three sandstones. A two-dimensional T1-Δχapp correlation (where Δχapp is the apparent solid/liquid magnetic susceptibility contrast) reveals the microscopic heterogeneity in composition, whilst a spatially resolved T1 profile reveals the macroscopic structural heterogeneity. To perform these measurements efficiently, a rapid measure of longitudinal T1 relaxation time has been implemented on a low-field NMR spectrometer with a magnetic field strength B0=0.3 T. The "double-shot" T1 pulse sequence is appropriate for analysis of porous materials in general. Example relaxation time distributions are presented for doped water phantoms to validate the method. The acquisition time of the double-shot T1 sequence is equivalent to the single-shot Carr-Purcell Meiboom-Gill (CPMG) sequence used routinely in petrophysics to measure transverse T2 relaxation. Rapid T1 measurements enable practical studies of core plugs at magnetic field strengths previously considered inappropriate, as T1 is independent of molecular diffusion through pore-scale (internal) magnetic field gradients.
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Affiliation(s)
- Jonathan Mitchell
- Schlumberger Gould Research, High Cross, Madingley Road, Cambridge CB3 0EL, UK.
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16
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Mitchell J, Gladden LF, Chandrasekera TC, Fordham EJ. Low-field permanent magnets for industrial process and quality control. PROGRESS IN NUCLEAR MAGNETIC RESONANCE SPECTROSCOPY 2014; 76:1-60. [PMID: 24360243 DOI: 10.1016/j.pnmrs.2013.09.001] [Citation(s) in RCA: 77] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/17/2013] [Revised: 09/19/2013] [Accepted: 09/19/2013] [Indexed: 05/13/2023]
Abstract
In this review we focus on the technology associated with low-field NMR. We present the current state-of-the-art in low-field NMR hardware and experiments, considering general magnet designs, rf performance, data processing and interpretation. We provide guidance on obtaining the optimum results from these instruments, along with an introduction for those new to low-field NMR. The applications of lowfield NMR are now many and diverse. Furthermore, niche applications have spawned unique magnet designs to accommodate the extremes of operating environment or sample geometry. Trying to capture all the applications, methods, and hardware encompassed by low-field NMR would be a daunting task and likely of little interest to researchers or industrialists working in specific subject areas. Instead we discuss only a few applications to highlight uses of the hardware and experiments in an industrial environment. For details on more particular methods and applications, we provide citations to specialized review articles.
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Affiliation(s)
- J Mitchell
- Department of Chemical Engineering and Biotechnology, University of Cambridge, Pembroke Street, Cambridge CB2 3RA, United Kingdom; Schlumberger Gould Research, High Cross, Madingley Road, Cambridge CB3 0EL, United Kingdom
| | - L F Gladden
- Department of Chemical Engineering and Biotechnology, University of Cambridge, Pembroke Street, Cambridge CB2 3RA, United Kingdom.
| | - T C Chandrasekera
- Department of Chemical Engineering and Biotechnology, University of Cambridge, Pembroke Street, Cambridge CB2 3RA, United Kingdom
| | - E J Fordham
- Schlumberger Gould Research, High Cross, Madingley Road, Cambridge CB3 0EL, United Kingdom
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17
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Bernin D, Topgaard D. NMR diffusion and relaxation correlation methods: New insights in heterogeneous materials. Curr Opin Colloid Interface Sci 2013. [DOI: 10.1016/j.cocis.2013.03.007] [Citation(s) in RCA: 40] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
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