Patent ID: 8637807
Filing Date: 2014-01-28
Classification: G01V

Abstract:
1. A method for measuring characteristics of a formation surrounding a borehole using an apparatus comprising a pulsed neutron source, wherein the method comprises: emitting neutrons from the neutron source into the formation; emitting gamma rays from the gamma ray source into the formation; detecting neutrons and gamma rays returning to the neutron section from the formation resulting from irradiation of the formation with neutrons; detecting gamma rays returning to the gamma ray section from the formation resulting from the irradiation of the formation with gamma rays; synchronizing the gamma ray measurement in the gamma ray section with operation of the pulsed neutron source; measuring the difference in gamma ray measurements between the on and off periods of the pulsed neutron source; and analyzing the detected gamma rays and neutrons to provide an indication of the characteristics of the formation.