摘要
苏里格气田是鄂尔多斯盆地上古生界内发现的大型岩性气藏。天然气中甲烷占绝对优势,干燥系数低,为湿气。天然气的单体碳同位素具有碳数越高,同位素越重的特点,且正构烷烃碳同位素具有δ13C1<1δ3C3<1δ3C2<1δ3C4的规律。甲烷碳同位素与甲烷含量呈正相关,与乙烷含量为负相关。根据天然气单体碳同位素及其含量变化,认为苏里格天然气属煤成气。天然气中含少量CO2气,多为有机成因。苏里格气田二叠系气藏的形成与演化可划分为石炭—二叠纪至中侏罗世气源岩沉积埋藏阶段、晚侏罗世至白垩纪天然气形成阶段和第三纪至现今的保存改造阶段。
The Sulige Gas Field is a giant litholitic gas reservoir in the Upper Palaeozoic strata in the Ordos Basin. The determinations of gas chromatography indicates a kind of humid gas with lower dryness and dominant methane. The carbon isotopes in n-alkane exhibit a trend of δC1 〈 δC3 〈 δC2 〈δC4. There is a positive correlation between the carbon isotopes and methane contents, and a negative correlation between the carbon isotopes and ethane contents. The variations in the contents of carbon isotopes show that the natural gas from the Sulige Gas Field is a kind of coal-derived gas of organic origin and contains minor amount of CO2. The Permian gas reservoirs went through the deposition and burial of the source rocks during the Carboniferous - Permian to the Middle Jurassic, formation of the gas during the Late Jurassic to the Cretaceous, and preservation and modification of the gas from the Tertiary onwards.
出处
《沉积与特提斯地质》
CAS
CSCD
2009年第2期77-82,共6页
Sedimentary Geology and Tethyan Geology
关键词
苏里格气田
上古生界
地球化学特征
成藏
Sulige Gas Field
Upper Palaeozoic strata
geochemistry
gas accumulation