Halliburton Energy Services, Inc.

Numar Corporation

Stefan K Menger

Manfred G Prammer

George David Goodman

Sergey Knizhnik

Edward J Harris, Iii

Earle Drack

Edward J Iii Harris

An NMR logging tool for conducting NMR measurements in a plurality of sensitive volumes ranging up to a meter from the tool. The tool comprises a magnetic assembly using one or more permanent magnets and at least one pole piece for extending a magnet pole and shaping the magnetic field to simulate a magnetic monopole in a sensitive volume within the formation. Different embodiments of a segmented antenna enable directional NMR logging. The tool embodiments and methods of their use are suitable for wireline or LWD logging, and can be used for directional drilling.

Systems and methods for deep-looking NMR logging

Proposed is a new method and system to obtain enhanced-resolution NMR data by merging, in the time domain, different NMR pulse echo trains into a single echo train. The input echo trains can be acquired with different inter-echo spacing, wait time, and signal-to-noise ratio parameters that are optimized to correspond to both fast and slow portions of the T spectrum. The merged echo trains are inverted into complete T spectra in a single step thereby overcoming ambiguities and other limitations of prior art methods. In a preferred embodiment the merging process does not require a priori information about T , and the merged echo trains are optimized in with respect to T resolution. The method of this invention is preferably practiced with the latest generation of multi-volume NMR logging tools, that allow simultaneous recordation of NMR data with different inter-echo spacing T , wait time T , and signal-to-noise ratio (SNR) parameters.

Method and apparatus for merging of NMR echo trains in the time domain

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Exton, PA, United States of America

Stefan K Menger