Patent ID: 7796263
Filing Date: 2010-09-14
Classification: E21B,G01V

Abstract:
1. A method for estimating a property of a fluid downhole, the method comprising; conveying a semiconductor light emitter in a well borehole, the semiconductor light emitter having a gain region that produces light; emitting a light from the semiconductor light emitter toward a fluid sample, the emitted light having a first center wavelength responsive to a selected fluid property; applying an electrical current pulse train to the semiconductor light emitter, the electric current pulse train having a duty cycle; analyzing a first response of the emitted light after interaction with the fluid sample to estimate the fluid property using the first center wavelength; changing the duty cycle of the electrical current pulse train to vary a temperature of the gain region to change the first center wavelength in the emitted light to a second center wavelength; and analyzing a second response of the emitted light after interaction with the fluid to estimate the fluid property using the second center wavelength.