METHOD FOR DETECTING HYDROCARBONS BY COMPARING NMR RESPONSE AT DIFFERENT DEPTHS OF INVESTIGATION

摘要

A method for detecting hydrocarbon-bearing zones in a formation penetrated byawellbore includes acquiring at least two nuclear magnetic resonancemeasurements, each ofthe at least two nuclear magnetic resonance measurements acquired from avolume ofinvestigation at a different radial depth from the wellbore; and determiningwhether theformation bears hydrocarbons by comparing the at least two nuclear magneticresonancemeasurements. A method for detecting fines invasion in a formation surroundinga wellboreincludes acquiring at least two nuclear magnetic resonance measurements, eachof the at leasttwo nuclear magnetic resonance measurements acquired from a volume ofinvestigation at adifferent radial depth from the wellbore; and determining whether the finesinvasion hasoccurred by comparing the at least two nuclear magnetic resonancemeasurements.