摘要
笔者等在青海省祁连山冻土区实施的科学钻探试验井中,直接钻获到白色冰状实物样品,并观察到燃烧现象,经激光拉曼光谱仪检测为天然气水合物,这是首次在中国陆域勘查到的天然气水合物。天然气水合物主要产于泥岩、油页岩、粉砂岩、细砂岩等层段中,与岩性关系不大;常出露在岩层的裂隙和孔隙中,受裂隙的控制比较明显;纵向上分布不连续,主要出现在井下130～400m之间,横向上无明显的对比关系。该区天然气水合物可能首先受到祁连山冻土特征等所确定的天然气水合物稳定带的限制,产出的具体部位受断裂及气源条件的双重控制,产生的烃类气体在不同级次断裂的疏导和上覆冻土层低温的共同耦合作用下,更易于在裂隙中形成天然气水合物。
Four scientific experimental wells were drilled in the Qilian Mountain permafrost area of Qinghai Province in the winter of 2008 and the summer of 2009. Gas hydrate was directly obtained and white ice-like gas hydrate and its burning phenomena were observed from three of the four wells. These results were confirmed by lab-based Raman spectroscopy. In all the 4 wells, gas hydrate related anomalous phenomena were also recorded. It is the first time for researchers to find gas hydrate in China＇ s continent. Gas hydrate and its related anomalous phenomena occur in such rocks as mudstone, oil shale, siltstone and fine-grained sandstone and are not obviously related to lithology; they mainly occur in fissures and pore space and are evidently controlled by fissures; they are vertically discontinuously distributed and horizontally irrelatively arranged; they occur from 130 m to 400 m below the surface. In the study area, gas hydrate and its related anomalous phenomena are probably confined mainly to the gas hydrate stability zone based on permafrost features; individual gas hydrate occurrences are controlled jointly by fissures and gas sources. When hydrocarbon gases are generated by organic matter, they are driven by all grades of fractures to migrate upwards; when they arrive in the stability zone, they are coupled by cryogenic permafrost, leading to their preferable occurrence in fissures.
出处
《矿床地质》
CAS
CSCD
北大核心
2010年第1期182-191,共10页
Mineral Deposits
基金
中国地质调查局地质大调查项目"我国冻土区天然气水合物资源调查与评价"(编号:N0808)
中央公益性科研院所基本科研业务费专项基金项目"青藏高原多年冻土区天然气水合物形成条件模拟技术研究"(编号:K0718)
国家重点基础研究发展计划项目"南海天然气水合物富集规律与开采基础研究"(2009CB219501)的资助
关键词
地质学
天然气水合物
地质特征
冻土
祁连山
青海
geology, gas hydrate, geological characteristics, permafrost, Qilian Mountain, Qinghai
