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de Kort DW, Reci A, Ramskill NP, Appel M, de Jong H, Mantle MD, Sederman AJ, Gladden LF. Acquisition of spatially-resolved displacement propagators using compressed sensing APGSTE-RARE MRI. JOURNAL OF MAGNETIC RESONANCE (SAN DIEGO, CALIF. : 1997) 2018; 295:45-56. [PMID: 30096552 DOI: 10.1016/j.jmr.2018.07.012] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/09/2018] [Revised: 07/14/2018] [Accepted: 07/16/2018] [Indexed: 06/08/2023]
Abstract
A method is presented for accelerating the acquisition of spatially-resolved displacement propagators via under-sampling of an Alternating Pulsed Gradient Stimulated Echo - Rapid Acquisition with Relaxation Enhancement (APGSTE-RARE) data acquisition with compressed sensing image reconstruction. The method was demonstrated with respect to the acquisition of 2D spatially-resolved displacement propagators of water flowing through a packed bed of hollow cylinders. The q,k-space was under-sampled according to variable-density pseudo-random sampling patterns. The quality of compressed sensing reconstructions of spatially-resolved propagators at a range of sampling fractions was assessed using the peak signal-to-noise ratio (PSNR) as a quality metric. Propagators of good quality (PSNR 33.2 dB) were reconstructed from only 6.25% of all data points in q,k-space, resulting in a reduction in the data acquisition time from 4 h to 14 min. The spatially-resolved propagators were reconstructed using both the total variation and nuclear norm sparsifying transforms; use of total variation resulted in a slightly higher quality of the reconstructed image in most cases. To illustrate the power of this method to characterise heterogeneous flow in porous media, the method is applied to the characterisation of flow in a vuggy carbonate rock.
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Affiliation(s)
- Daan W de Kort
- Magnetic Resonance Research Centre, Department of Chemical Engineering and Biotechnology, University of Cambridge, Philippa Fawcett Drive, Cambridge CB3 0AS, United Kingdom
| | - Andi Reci
- Magnetic Resonance Research Centre, Department of Chemical Engineering and Biotechnology, University of Cambridge, Philippa Fawcett Drive, Cambridge CB3 0AS, United Kingdom
| | - Nicholas P Ramskill
- Magnetic Resonance Research Centre, Department of Chemical Engineering and Biotechnology, University of Cambridge, Philippa Fawcett Drive, Cambridge CB3 0AS, United Kingdom
| | - Matthias Appel
- Shell Technology Center, 3333 Highway 6 S, Houston, TX 77082, USA
| | - Hilko de Jong
- Shell Technology Center, 3333 Highway 6 S, Houston, TX 77082, USA
| | - Michael D Mantle
- Magnetic Resonance Research Centre, Department of Chemical Engineering and Biotechnology, University of Cambridge, Philippa Fawcett Drive, Cambridge CB3 0AS, United Kingdom
| | - Andrew J Sederman
- Magnetic Resonance Research Centre, Department of Chemical Engineering and Biotechnology, University of Cambridge, Philippa Fawcett Drive, Cambridge CB3 0AS, United Kingdom
| | - Lynn F Gladden
- Magnetic Resonance Research Centre, Department of Chemical Engineering and Biotechnology, University of Cambridge, Philippa Fawcett Drive, Cambridge CB3 0AS, United Kingdom.
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Colbourne AA, Sederman AJ, Mantle MD, Gladden LF. Accelerating flow propagator measurements for the investigation of reactive transport in porous media. JOURNAL OF MAGNETIC RESONANCE (SAN DIEGO, CALIF. : 1997) 2016; 272:68-72. [PMID: 27662402 DOI: 10.1016/j.jmr.2016.08.018] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/20/2016] [Revised: 08/31/2016] [Accepted: 08/31/2016] [Indexed: 06/06/2023]
Abstract
NMR propagator measurements are widely used for identifying the distribution of molecular displacements over a given observation time, characterising a flowing system. However, where high q-space resolution is required, the experiments are time consuming and therefore unsuited to the study of dynamic systems. Here, it is shown that with an appropriately sampled subset of the q-space points in a high-resolution flow propagator measurement, one can quickly and robustly reconstruct the fully sampled propagator through interpolation of the acquired raw data. It was found that exponentially sampling ∼4% of the original data-points allowed a reconstruction with the deviation from the fully sampled propagator below the noise level, in this case reducing the required experimental time from ∼2.8h to <7min. As a demonstration, this approach is applied to observe the temporal evolution of the reactive flow of acid through an Estaillades rock core plug. It is shown that 'wormhole' formation in the rock core plug provides a channel for liquid flow such that the remaining pore space is by-passed, thereby causing the flow velocity of the liquid in the remaining part of the plug to become stagnant. The propagator measurements are supported by both 1D profiles and 2D imaging data. Such insights are of importance in understanding well acidisation and CO2 sequestration processes.
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Affiliation(s)
- A A Colbourne
- University of Cambridge, Department of Chemical Engineering and Biotechnology, Pembroke Street, Cambridge CB2 3RA, UK
| | - A J Sederman
- University of Cambridge, Department of Chemical Engineering and Biotechnology, Pembroke Street, Cambridge CB2 3RA, UK.
| | - M D Mantle
- University of Cambridge, Department of Chemical Engineering and Biotechnology, Pembroke Street, Cambridge CB2 3RA, UK
| | - L F Gladden
- University of Cambridge, Department of Chemical Engineering and Biotechnology, Pembroke Street, Cambridge CB2 3RA, UK
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Singer PM, Mitchell J, Fordham EJ. Characterizing dispersivity and stagnation in porous media using NMR flow propagators. JOURNAL OF MAGNETIC RESONANCE (SAN DIEGO, CALIF. : 1997) 2016; 270:98-107. [PMID: 27434778 DOI: 10.1016/j.jmr.2016.07.004] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/20/2016] [Revised: 07/11/2016] [Accepted: 07/11/2016] [Indexed: 06/06/2023]
Abstract
Low-field nuclear magnetic resonance (NMR) displacement probability distributions (flow propagators) are presented for water flowing through heterogeneous porous materials. Four sedimentary rocks have been chosen as example systems: Dolostone, Bentheimer sandstone, Berea sandstone, and Indiana limestone (in order of decreasing permeability). The fluid displacement is characterized by pre-asymptotic Stokes' flow and so the probability distributions are bimodal, with peaks corresponding to stagnant fluid in dead-end pores and flowing fluid in the connected porosity. Cut-off Gaussian functions are used to fit the flowing and stagnant peaks independently. An effective dispersivity length scale Lv (also known as the mixing length scale) is estimated by fitting the portion of the probability distribution corresponding to the flowing fluid. For the relatively homogeneous Bentheimer sandstone, the ratio of effective dispersivity length scale to effective transport diameter dt is Lv/dt≈16, which is an order of magnitude larger than for randomly packed glass beads where Lv/dt≈1.8. We compare these dispersivity parameters to similar values extracted from a cumulant analysis of the entire propagator. Fitting a cut-off Gaussian avoids the usual complications of analyzing dispersion in the presence of the ubiquitous stagnant fluid, and results in a clear demonstration of the influence of long-range heterogeneities on the dispersivity for flow in real sedimentary rocks.
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Affiliation(s)
- P M Singer
- Schlumberger-Doll Research, 1 Hampshire Street, Cambridge, MA 02139, USA
| | - J Mitchell
- Schlumberger Gould Research, High Cross, Madingley Road, Cambridge CB3 0EL, UK.
| | - E J Fordham
- Schlumberger Gould Research, High Cross, Madingley Road, Cambridge CB3 0EL, UK
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Behr W, Behr VC, Reichenauer G. Self diffusion coefficients of organic solvents and their binary mixtures with CO2 in silica alcogels at pressures up to 6MPa derived by NMR pulsed gradient spin echo. J Supercrit Fluids 2015. [DOI: 10.1016/j.supflu.2015.05.024] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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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: 128] [Impact Index Per Article: 12.8] [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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Sham E, Mantle MD, Mitchell J, Tobler DJ, Phoenix VR, Johns ML. Monitoring bacterially induced calcite precipitation in porous media using magnetic resonance imaging and flow measurements. JOURNAL OF CONTAMINANT HYDROLOGY 2013; 152:35-43. [PMID: 23872026 DOI: 10.1016/j.jconhyd.2013.06.003] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/21/2012] [Revised: 06/05/2013] [Accepted: 06/10/2013] [Indexed: 06/02/2023]
Abstract
A range of nuclear magnetic resonance (NMR) techniques are employed to provide novel, non-invasive measurements of both the structure and transport properties of porous media following a biologically mediated calcite precipitation reaction. Both a model glass bead pack and a sandstone rock core were considered. Structure was probed using magnetic resonance imaging (MRI) via a combination of quantitative one-dimensional profiles and three-dimensional images, applied before and after the formation of calcite in order to characterise the spatial distribution of the precipitate. It was shown through modification and variations of the calcite precipitation treatment that differences in the calcite fill would occur but all methods were successful in partially blocking the different porous media. Precipitation was seen to occur predominantly at the inlet of the bead pack, whereas precipitation occurred almost uniformly along the sandstone core. Transport properties are quantified using pulse field gradient (PFG) NMR measurements which provide probability distributions of molecular displacement over a set observation time (propagators), supplementing conventional permeability measurements. Propagators quantify the local effect of calcite formation on system hydrodynamics and the extent of stagnant region formation. Collectively, the combination of NMR measurements utilised here provides a toolkit for determining the efficacy of a biological-precipitation reaction for partially blocking porous materials.
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Affiliation(s)
- E Sham
- Department of Chemical Engineering and Biotechnology, University of Cambridge, Pembroke Street, Cambridge CB2 3RA, UK
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