由于太赫兹波对极性物质有很高的灵敏度，因此可以利用太赫兹时域光谱技术检测沙粒中含有的微量原油。将微量的原油浓度与太赫兹衰减系数之间建立起线性模型。同时引入有效介质理论来证实太赫兹介电常数与原油含量低于200 ppm之间的线性关系。结果表明，太赫兹时域光谱技术可以成为检测沙粒中微量原油泄漏的有效方法。

Terahertz time-domain spectroscopy (THz-TDS) was used to detected the trace crude oil mixed into the sands away from wells due to the high sensitivity to polar substance. A linear model was established between the trace crude oil concentration and the terahertz attenuation coefficient. Effective-medium theory was introduced to confirm the linear relationship between the terahertz dielectric constant and the crude oil content below 200 ppm. The research suggests that terahertz time-domain spectroscopy can be an effective method for detecting the trace crude oil leakage in sands.