天然气水合物气体组成分析的样品前处理技术  

Sample Pre-treatment Technologies for Gas Composition Analysis of Natural Gas Hydrates

作　　者：贺行良[1,2,3] 刘昌岭[1,2] 王江涛[3] 孟庆国[1,2] 

机构地区：[1]国土资源部海洋油气资源与环境地质重点实验室,山东青岛266071 [2]青岛海洋地质研究所,山东青岛266071 [3]中国海洋大学海洋化学理论与工程技术教育部重点实验室,山东青岛266100

出　　处：《岩矿测试》2013年第2期284-289,共6页Rock and Mineral Analysis

基　　金：国家自然科学基金项目(41072037);国土资源部公益性行业科研专项(201111026);中国地质大调查项目(1212011120271)

摘　　要：天然气水合物仅在相对低的温度和高压条件下稳定存在,一旦脱离其稳定条件就将分解成气体和水而不复存在,因此水合物样品的储存与制备等相关前处理过程对其气体组成的准确测定十分重要。本文实验研究了天然气水合物在常压条件下的最佳储存温度、最佳分解方法、分解气的最佳收集与储存方式,以及非水合物气体的排除等样品前处理技术。结果表明:天然气水合物在常压下低于-100℃储存为妥;样品在进行分解脱气时,"顶空法"和"注射器法"适用性较广,"排水法"不适用于含CO2的水合物样品,且样品分解前最好于-80℃放置片刻以去除表面吸附的非水合物气体。水合物分解气体的储存应尽量避免使用铝塑气袋,建议采用丁基橡胶塞密封的玻璃顶空瓶,并于5天内完成气体组成测定为佳。Natural gas hydrate can only steadily exist at lower temperature and higher pressure, otherwise it will decompose into gas and water. Hereby, the pre-treatments （sample preservation, preparation, etc. ） are very important to the accurate measurement of gas components of gas hydrate. Described in this paper are the pre- treatment technologies of gas hydrate that were studied experimentally, mainly including the optimal preservation temperature under atmospheric pressure, the optimal decomposition methods, the optimal ways of gas collecting and storing, and the removal methods of non-hydrate gases. The results indicate that the best temperature for gas hydrate storage is less than -100℃ under atmospheric pressure. The headspace method and syringe method can be widely used in hydrate-bound gases＇ decomposition and collection, however, the drainage method was not suitable for hydrate samples containing CO2. It was more beneficial to place the sample at - 80℃ to remove the non-hydrate gases absorbed on the surface of the specimen. In addition, the use of a glass bottle with butyl rubber plug for storage of hydrate decomposition gases instead of aluminum-plastic air bag is preferential, and the optimum time to finish the analysis of molecular compositions is within 5 days.

关 键 词：天然气水合物 样品储存 脱气分解 气体收集与储存 

分 类 号：TE122[石油与天然气工程—油气勘探]