Nuclear magnetic resonance logging tool having an array of antennas

Various disclosed nuclear magnetic resonance (NMR) logging systems and methods employ an array of antennas to provide increased resolution without sacrificing signal-to-noise ratio. Certain method embodiments include: establishing a static magnetic field (BO) with a tool moving along a borehole thro...

Ausführliche Beschreibung

Gespeichert in:
Bibliographische Detailangaben
Hauptverfasser: SERGEL KNIZHNIK, REBECCA C JACHMANN, ROBERT EPSTEIN, MARIAN L MORYS
Format: Patent
Sprache:eng
Schlagworte:
Online-Zugang:Volltext bestellen
Tags: Tag hinzufügen
Keine Tags, Fügen Sie den ersten Tag hinzu!
Beschreibung
Zusammenfassung:Various disclosed nuclear magnetic resonance (NMR) logging systems and methods employ an array of antennas to provide increased resolution without sacrificing signal-to-noise ratio. Certain method embodiments include: establishing a static magnetic field (BO) with a tool moving along a borehole through a formation; concurrently driving a multiple antenna cells to produce a radio frequency field (Bl) in said formation; measuring an individual response from each antenna cell as nuclear spins undergo precession in the formation; and determining at least one characteristic relaxation time of the formation based at least in part on the individual response. The individual responses can be associated with positions where the individual responses were measured, and the relaxation time can be determined from a combination of those responses associated with a given position. Certain responses may be excluded due to tool motion that degrades the measured response.