江汉含油气盆地土壤光谱特征及烃类蚀变信息提取方案

SPECTRAL CHARACTERISTICS OF SOIL IN JIANGHAN BASIN AND THE EXTRACTING METHOD OF HYDROCARBON MICROSEEPAGE ALTERATION INFORMATION

江汉含油气盆地土壤样品显示出较强的与烃类微渗漏蚀变相关的光谱特征和地球化学成分特征；选择相关系数最高的ＴＭ波段，用ＴＭ２／ＴＭ３、ＴＭ３／ＴＭ４和ＴＭ５／ＴＭ７进行比值处理，达到了在油区去相关的目的；ＴＭ２／ＴＭ３、ＴＭ３／ＴＭ４和ＴＭ５／ＴＭ７在油区存在和同一化学成分的反向相关性，说明运用上述３个比值为基础的彩色图象处理能增强对化学成分的分辨率；从光谱数据中直接提取出油气蚀变信息，并以此提出了在该区以比值法进行烃类蚀变信息的图象提取方案。

The soil over the oil caps in the Jianghan Basin shows strong spetractal and geochemical characteristics,which indicate hydrocarbon microseepage alteration. Using the TM2 and TM3,TM3 and TM4,and TM5 and TM7 bands which have the best correlation with each other in spectral data processing,decorrelation in oil area was achieved.The ratio processing raises the correlation between the reflectance of TM bands and the chemical compositions related to the oil-gas hydrocarbon microseepage alteration.