Patent ID: 6242912
Filing Date: 2001-06-05
Classification: G01N,G01V,Y02A

Abstract:
A method for determination of petrophysical properties of a geologic formation using NMR logging measurements comprising the steps of:providing a first set of CPMG pulses associated with a first recovery time TR.sub.1 ;providing a second set of CPMG pulses associated with a second recovery time TR.sub.2, the first and second set of CPMG pulses being provided in the same logging pass;receiving NMR echo signals in response to said first and said second set of CPMG pulses;combining data representing NMR echo signals received in response to pulses in said first set and data representing NMR echo signals received in response to pulses in said second set to form a composite signal comprising data pairs, each pair corresponding to substantially the same depth mark in the formation; wherein one element of the data pair is associated with the first recovery time and a second element of the data pair is associated with the second recovery time;generating a difference signal by pair-wise subtraction of the elements of the composite signal; anddetermining petrophysical properties of the geologic formation on the basis of the generated difference signals.