摘要
青海木里煤田发现的天然气水合物,主要产自下部煤层和页岩层,为典型煤成气及页岩气。青藏高原永冻层为天然气水合物形成提供盖层圈闭条件,断层、裂隙、砂体及不整合面为天然气水合物形成提供输导系统,砂体为其形成提供储层。天然气水合物在测井曲线上表现为低密度值、高电阻率、高声速、高天然伽马及井径变大或基本不变,化学组成以CH4、N2为主,含少量O2、C2H6及CO2。在对天然气水合物形成条件及特征研究基础上,提出天然气水合物形成模式:断层为疏导系统,不整合面为疏导系统,渗透性好的砂体为疏导系统。
The gas hydrates was discovered in the coal and shale of the Jurassic coal measures in the Muli coalfield, and the gas sources were coal and shale. The Permafrost in Tibetan plateau provides cap-rock for gas hydrate. The Fault, fracture, sand body and unconformity supply conducting system for gas, and the sand body also offers as reservoir. The gas hydrates has a low density value, high resistivity, high velocity, high natural gamma and increasing well diameter of logging curve. Chemical compositions are mainly CH4, N2 , with a small amount of O2, C2H6 and CO2. Based on the study of forming condition and characteristics of gas hydrates, we have proposed a model of gas hydrates accumulation;fault plays a role of migration system, disconformity acts as migration system, well-permeable sandstones act as migra-tion and reservoir system.
出处
《新疆地质》
CAS
CSCD
北大核心
2013年第2期223-227,共5页
Xinjiang Geology
基金
国家科技重大专项<低煤阶煤层气富集规律与有利区块预测>(2011ZX05033-002)
中国地质调查局项目<青藏高原冻土带天然气水合物调查评价>(1212010818055)联合资助
关键词
青海
木里煤田
天然气水合物
特征
成藏模式
Qinghai
Muli coalfield
Gas hydrates
Characteristic
Accumulating model
