Patent ID: 6072567
Filing Date: 2000-06-06
Classification: G01H,G01V

Abstract:
A vertical seismic profiling system for performing a vertical seismic profile of an earth formation (12, 14, 16) in relation to a borehole (10), comprising:seismic disturbance force means (42, 45) being arranged at a selected distance from the borehole (10) for providing a seismic disturbance force (52, 54) to be sensed to perform the vertical seismic profile of the earth formation (12, 14, 16) in relation to the borehole (10);vertical seismic profiling optical signal processing equipment (35, 135), for providing an optical signal, and-being responsive to a fiber Bragg Grating optical seismic sensor signal, for further providing vertical seismic profile information about the earth formation (12, 14, 16) in relation to the borehole (10) depending on the information contained in the fiber Bragg Grating optical seismic sensor signal; andan optical fiber having fiber Bragg Grating optical seismic sensors (20, 22, 23, 24, 25, 28) spaced at a desired interval therein, arranged in the borehole (10), and distributed along a selected length of the borehole (10), responsive to the optical signal, and further responsive to the seismic disturbance force (52, 54) in relation to the borehole (10), for transforming the seismic disturbance force (52, 54) into the fiber Bragg Grating optical seismic sensor signal using a direct mechanical-to-optical energy conversion and without using an electrical energy conversion, and for providing the fiber Bragg Grating optical seismic sensor signal containing information about the seismic disturbance force (52, 54) in relation to the borehole (10) to the optical signal processing equipment (35, 135).