A METHOD FOR CORRECTING SIGNALS RECEIVED FROM AN EARTH FORMATION USING A A NUCLEAR MAGNETIC RESONANCE TOOL

摘要

Estimates of ringing produced by short recovery pulse sequences (CPMG or modified CPMG) are used to improve the effects of ringing in a conventional CPMG or modified CPMG sequences. This is an effective method for removal of ringing when the ringing is varying over a time interval that would be spanned by a phase alternated pair of conventional sequences. By use of frequency dithering, ringing due to the excitation pulse and the refocusing pulses can be removed.