Nuclear magnetic resonance (NMR) ringing noise measurements in well systems

Abstract

Systems, methods, and apparatus, including computer programs encoded on computer-readable media, for obtaining nuclear magnetic resonance (NMR) measurements of a subsurface formation in a well system. One or more NMR pulses are generated downhole using an NMR tool of the well system. It is determining whether an amplitude of an NMR echo signal is less than or equal to a threshold level or the NMR echo signal is not present. Ringing noise associated with the one or more NMR pulses is measured when the amplitude of the NMR echo signal is less than or equal to the threshold level or the NMR echo signal is not present. The ringing noise is cancelled from the NMR measurements, and properties of the subsurface formation are determined from the NMR measurements after cancelling the ringing noise.

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