摘要
川西坳陷中段天然气的组份以烃类气体为主，占气体总体积的98．1％～99．7％；非烃气体以CO2和N2为主，其含量分别占气体的0．12％～1．32％和0．25％～1．54％；烃类气体中以甲烷占绝对优势，平均含量为95．83％；重烃含量较低，平均为3．21％；干燥系数（C1／C1-5）平均为0．97，整体上属典型的干气。川西坳陷中段的所有样品δ^13C2都大于-25．8‰，属于典型的煤型气范畴，天然气的δ^13C1〈δ^13C2〈δ^13C3，呈明显的正序排列，显示出天然气为典型的有机成因。甲烷碳同位素组成，反映了其母质演化程度已处于成熟～高成熟阶段，且以高成熟阶段为主。
Natural gas in the middle section of western Sichuan Depression is mainly composed of hydrocarbon gas with an average content of 981%~997%. The non-hydrocarbon gas is mainly composed of CO2 and N2 with content of 012～132% and 025～154%,respectively. Hydrocarbon gas is mainly composed of methane with average contents of 9583%, while the heavy hydrocarbon has an average content of 321%. The drying coefficient (C1/C1-5)averages 097, indicating typical dry gas as a whole. The δ13C2 values of all samples in this area are more than -258‰, Indicating that it is of petroleum coal-type gas; and the δ13C values are obvious positive sequence, ie. δ13C1<δ13C2<δ13C3, indicating that it is typically of organic origin. The carbon isotope composition of me-thane reveals that the evolution of its source rocks is in the range of mature to high-mature stages, and is mainly in highly high-mature stage.
出处
《物探化探计算技术》
CAS
CSCD
2008年第4期326-330,265,共5页
Computing Techniques For Geophysical and Geochemical Exploration
关键词
组份
碳同位素
煤型气
天然气
川西坳陷
component
carbon isotope
coal-type gas
natural gas
western Sichuan depression
