Patent ID: 6573715
Filing Date: 2003-06-03
Classification: G01R,G01V,G02B

Abstract:
An EPR/NMR apparatus for detecting petrophysical features of a fluid-filled underground formation having a region of static magnetic field sensitivity, comprising:at least one antenna for providing an RF magnetic field in said region at an EPR frequency, and for receiving an EPR response signal from the fluid; a transmitter operable to provide power at said EPR frequency; a detector for receiving said ESR response signal from said antenna; a processor operable to analyze said EPR response signal by relating the amplitude of said EPR response signal to an estimated amount of crude oil in said underground formation; at least one antenna for providing an RF magnetic field in said region at an NMR frequency and for receiving an NMR response signal, and wherein said processor is further programmed to analyze said NMR response signal by relating the amplitude of said NMR response signal to an estimated amount of hydrogen-bearing fluid in said underground formation; and a transmitter operable to provide power at said NMR frequency to said antenna; wherein said processor is further operable to calculate the oil and water fractions in said fluid, to determine a NMR relaxation rate, and to calculate a pore size distribution of pores of said underground formation, based on said relaxation rate.