Patent ID: 7227129
Filing Date: 2007-06-05
Classification: E21B,G01F,G01P

Abstract:
1. A method of determining a flow velocity of a first fluid in a borehole in an earth formation, the method comprising: (a) irradiating the earth formation with a pulsed radiation source; (b) obtaining a first temporal signal resulting from the irradiation, the first temporal signal comprising inelastic gamma rays, the first temporal signal indicative of a time of activation of the source; (c) obtaining at least one second temporal signal resulting from the irradiation, the second temporal signal comprising scattered gamma rays measured by at least one detector; and (d) determining the flow velocity based on analysis of the first temporal signal, the at least one second temporal signal, and a distance between one of (A) a location where the first temporal signal is measured and the at least one detector, and (B) the source and the at least one detector.