Patent ID: 6275645
Filing Date: 2001-08-14
Classification: G01N

Abstract:
A subsurface exploration method which comprises the steps of:(a) In a bore hole extending from ground level to a below-ground location, delimiting a chamber in the bore hole between upper and lower packers;(b) providing in said chamber a substance capable of excitation by a certain electromagnetic energy to cause re-emission of electromagnetic energy to cause re-emission of electromagnetic energy by the substance;(c) coupling said certain electromagnetic energy into said chamber between said upper and lower packers, thereby causing said substance to re-emit electromagnetic energy in said chamber;(d) coupling re-emitted electromagnetic energy out of said chamber to a measurement location;(e) guiding electromagnetic energy at least partway between said chamber and said measurement location and at least in a vicinity of said chamber with at least one electromagnetic energy waveguide; and(f) determining the concentration of said substance in said chamber from re-emitted electromagnetic radiation therefrom.