祁连山冻土区天然气水合物激光拉曼光谱特征

Laser-Raman spectroscopy characteristics of natural gas hydrates from Qilian Mountain permafrost

采用显微激光拉曼光谱技术在77K和常压下对祁连山木里煤田聚乎更矿区钻获的冻土区天然气水合物进行了测试．得到中国冻土区天然气水合物典型的激光拉曼谱图，从微观角度证实DK3孔的133．30m、139．52-139，92m和141．00m3段不同埋深的岩心中均有天然气水合物存在。对冻土区水合物的拉曼谱图进行详细研究，结合文献资料，初步判定3段不同埋深的水合物结构均为S1I型，并参照不同客体气体分子的特征振动信号对谱线的归属进行分析，得出了水合物中大致所含的气体组分。

Natural gas hydrates recovered from the Juhugeng ore district in the Muli coalfield of the Qilian Mountain were investigat- ed by micro-Raman spectroscopy at 77K and ambient pressure, and the representative Raman spectra of the natural gas hydrates in the permafrost were obtained. The measurements prove the existence of hydrates at the depths of 133.30m, 139.52-139.92m and 141.00m in the hole of DK3. Based on a detailed analysis of the Raman spectra and consulting the literatures available, the authors preliminarily judge that all of the hydrates at three different depths are of s Ⅱ. Furthermore, the spectral lines of different gas molecules trapped in the hydrates were identified by their characteristic vibration signatures, and the approximate components of the guest gases were determined.