Direct detection of onshore hydrocarbon microseepages by remote sensing techniques

Remote sensing to detect hydrocarbon microseepage onshore, has the advantage of recognizing marginal and submarginal low relief structural prospects and all stratigraphic traps that are overlooked by reflection seismograph, besides its fast speed and low cost. The hydrocarbon-induced surface alterations of soil and sediments and associated anomalous vegetation that can be identified from remote sensing imagery are reduction of ferric iron (red bed bleaching), conversion of mixed-layer clays and feldspars to kaolinite, increase of carbonate content and anomalous spectral reflectance of vegetation. Conventional remote sensing data mostly cover 0.4-2.5 μm wavelength region with broad bandwidth that cannot characterize the absorption features caused by hydrocarbon microseepage. High spectral resolution imaging data are demanded