SYSTEM AND METHODS FOR NMR SIGNAL PROCESSING WITHOUT PHASE ALTERNATED PAIR STACKING

摘要

A system and methods for improving the vertical resolution of NMR logs based on data acquisition methods and signal processing techniques that need not apply Phase Alternated Pair Stacking "PAPS". The method is based on reducing the level of coherent non-formation signals, by estimating these signals and removing the estimates from the underlying NMR pulse echo trains. Once the estimated non-formation signal components have been removed, standard NMR processing methods are applied to derive petrophysical properties of the formation (109) under investigation. In a preferred embodiment the NOPAPS method of this invention is practiced along with a data acquisition sequence , which can be used to further increase the logging speed of tool (106) or vertical resolutionof the measurements.