کد مقاله کد نشریه سال انتشار مقاله انگلیسی نسخه تمام متن
5404782 1505994 2016 11 صفحه PDF دانلود رایگان
عنوان انگلیسی مقاله ISI
Accurate phase-shift velocimetry in rock
ترجمه فارسی عنوان
سرعت سنج سرعت فازی دقیق در سنگ
موضوعات مرتبط
مهندسی و علوم پایه شیمی شیمی تئوریک و عملی
چکیده انگلیسی


- Propagator asymmetries are the main source of PFG phase-shift velocimetry errors.
- Symmetric propagators can be obtained for displacements dominated by self-diffusion.
- A method for accurate velocimetry in rocks and porous media is proposed.
- The validity of this method is demonstrated for a range of flow rates.

Spatially resolved Pulsed Field Gradient (PFG) velocimetry techniques can provide precious information concerning flow through opaque systems, including rocks. This velocimetry data is used to enhance flow models in a wide range of systems, from oil behaviour in reservoir rocks to contaminant transport in aquifers. Phase-shift velocimetry is the fastest way to produce velocity maps but critical issues have been reported when studying flow through rocks and porous media, leading to inaccurate results. Combining PFG measurements for flow through Bentheimer sandstone with simulations, we demonstrate that asymmetries in the molecular displacement distributions within each voxel are the main source of phase-shift velocimetry errors. We show that when flow-related average molecular displacements are negligible compared to self-diffusion ones, symmetric displacement distributions can be obtained while phase measurement noise is minimised. We elaborate a complete method for the production of accurate phase-shift velocimetry maps in rocks and low porosity media and demonstrate its validity for a range of flow rates. This development of accurate phase-shift velocimetry now enables more rapid and accurate velocity analysis, potentially helping to inform both industrial applications and theoretical models.

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ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Journal of Magnetic Resonance - Volume 267, June 2016, Pages 43-53
نویسندگان
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