川中与川西地区侏罗系天然气地球化学特征对比

Geochemical Characteristics and Comparison of Juassic Natural Gas in the West and Middle Sichuan

通过川西与川中地区侏罗系天然气中组分、轻烃及碳同位素特征比较,对两地区天然气地球化学特征进行分析。结果表明,两地区天然气组分均以烃类气体为主,烃类组分中甲烷占绝对优势,天然气中均不含H2S。川西地区甲烷含量明显高于川中地区,而重烃含量则明显低于川中地区;川西地区天然气以干气为主,川中地区以湿气为主。川西侏罗系天然气处于成熟—高成熟阶段,川中侏罗系天然气主要处于成熟阶段。川西与川中地区侏罗系天然气均为有机成因气,川西地区主要为煤型气,川中地区以油型气为主,部分为煤型气。

Analyzing and comparing the geochemical characteristics of Jurassic natural gas in the western and the middle Sichuan based on the characteristics of Gas Composition, Carbon Isotope and Light -hydrocarbon. The re- suits show that the natural gas composed of hydrocarbon gas in the both areas, the Hydrocarbon gas is mainly com- posed of methane, and natural gas hydrogen sulfide - free in these regions. The methane content in west Sichuan is significantly higher than in central Sichuan area, and the heavy hydrocarbon in the area of west Sichuan lower than in central Sichuan area. The natural gas in central Sichuan region is characterized by major wet gases, and the west of Sichuan region main shows a dry gas feature. The Jurassic natural gas in the western Sichuan exists in a matura- tion or over - maturation stage, and the Jurassic natural gas in the middle Sichuan is mainly in mature stage. They are all organic origin gas, the coal formed gas is mainly located in the western of Sichuan, and the main kind of natural gas of the Jurassic in the middle Sichuan is oil - type gas, partly to coal - type gas.