Patent ID: 8440961
Filing Date: 2013-05-14
Classification: G01V

Abstract:
1. An instrument for performing measurements downhole, the instrument comprising: an irradiator oriented to irradiate sub-surface materials surrounding the instrument, the irradiator comprising at least one neutron source disposed proximate to a moderator for providing a source of inelastic gamma photons and also disposed proximate to a material for providing a source of capture gamma photons, the irradiator producing an interrogating beam including both the inelastic gamma photons and the capture gamma photons; a first detector and a second detector, each detector for detecting gamma rays and oriented in a relationship to the irradiator for receiving gamma photons from at least one of the irradiator and the formation; and electronics for performing gamma energy spectroscopy; wherein the electronics provide for setting timing gates to discriminate between inelastic gamma photons and capture gamma photons.