黄土覆盖区油气微渗漏地表蚀变高光谱特征响应机理研究

以甘肃庆阳油气区为例,根据油气微渗漏的物理化学过程,通过地面实测黄土样品的波谱曲线,以及其中碳酸盐、粘土矿物、二、三价铁离子含量的测试分析,检测黄土覆盖区油气微渗漏所引起的特征光谱响应。根据黄土样品的测试分析,已知油气区碳酸盐矿物含量明显高于未知油气区,而且二价铁离子含量增加引起红层褪色现象明显,但粘土化蚀变特征不明显。从实测土壤光谱曲线包络线去除后,提取的土壤光谱吸收特征参数中,碳酸根和二价铁离子对应的吸收深度、吸收面积和对称度等三个特征参数与其含量相关性强,拟合度好。由此,对地面实测的14条土壤光谱曲线聚类分析能够有效区分油气微渗漏明显的已知油气区类和油气微渗漏不明显的未知油气区类。

Study on hyperspectral response to surface alteration by oil and gas microseepage under loess area

The present takes the Qingyang, Gansu as an example, based on the mechanism of oil-gas microseepage, the spectra of the loess samples were measured, and the contents of carbonate minerals, clay minerals, Fe2+ and Fe3+, were analyzed. From their contents, it was shown that the carbonate mineralization and the red fading phenomenon are obvious for the known oil-gas field. Meanwhile, the parameters of absorption spectra of the loess samples were identified after the continuum was removed. The multiple regression analysis between the spectrum parameters (independent variables) and the mineral contents (the dependent variables) was implemented. The results indicate that the absorption depth is more sensitive. Thus, by their spectrum absorption parameters, 14 spectra of loess samples were clustered into two groups: samples in the known oil-gas field and unknown oil-gas field.