A high sensitivity fiber Bragg grating seismic system and oil exploration test

Abstract

In this paper we report the development and field test of a high sensitivity fiber Bragg grating (FBG) geophone for geophysical imaging and monitoring application. A high sensitivity FBG geophone is designed, and its sensitivity is about 1000pm/g. The wavelength change of the FBG geophone is interrogated by using interferometric demodulation method, and the demodulation system noise is below 10-3 pm/ √Hz . And the minimum detectable seismic signal is below 1μg/ √Hz . We are presenting field test results for the FBG geophone and comparing its performance with regular exploration geophones. In comparison, FBG geophone has the advantages of higher signal-to-noise ratio and better low-frequency response. This work shows that using FBG technology to develop geophone for oil and gas exploration is both advantageous and feasible.