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Transverse relaxation measurements for moving samples in the presence of strong magnetic field gradients.

Transverse relaxation measurements for moving samples in the presence of strong magnetic field gradients.

Authors :
Gimenez Marassi, Agide
de Araújo-Ferreira, Arthur Gustavo
Lucas-Oliveira, Everton
Luiz Géa Vidoto, Edson
Donizeti Fernandes de Amorim, Aparecido
Andrighetto Trevizan, Willian
José Bonagamba, Tito
Source :
Journal of Magnetic Resonance. Sep2023, Vol. 354, pN.PAG-N.PAG. 1p.
Publication Year :
2023

Abstract

[Display omitted] • Effects of sample movement on T 2 measurement and relaxation times distribution; • Pore size distribution and total porosity of representative rock samples; • NMR Logging-while-drilling (LWD) system simulator; Nuclear Magnetic Resonance (NMR) is one of the primary techniques used in the oil industry for logging operations and in the laboratory environment to study rock formations due to its reliability in offering a reliable estimation of oil well productivity. Two types of well-logging operations exist, Wireline Logging and Logging While Drilling (LWD). Wireline Logging involves NMR measurements taken under static conditions. In contrast, LWD involves measurements taken during the drilling process while the tool is in motion, translating, rotating, and vibrating relative to the formation. To understand the behavior of NMR signals measured under LWD conditions on a laboratory scale, we developed a setup that includes a single-sided magnet, rf probes, and a mechanical system that emulates a relative sinusoidal motion between the sample and the applied magnetic field. Four representative rock samples were selected according to their relaxation times, which were short, intermediate, and long compared to the oscillation period of the LWD simulator: three sandstone, Fontainebleau, Berea Sandstone, and Portland Red, and one carbonate, Indiana Limestone. The results show that even with the modifications observed in the relaxation times distribution, which could lead to misinterpreting the geological formation parameters, the total porosity remains unaffected and independent of the sample motion during the NMR measurements, even under severe conditions and using the standard procedures of the data processing. [ABSTRACT FROM AUTHOR]

Details

Language :
English
ISSN :
10907807
Volume :
354
Database :
Academic Search Index
Journal :
Journal of Magnetic Resonance
Publication Type :
Academic Journal
Accession number :
171921455
Full Text :
https://doi.org/10.1016/j.jmr.2023.107522