雅克拉凝析气田油气地球化学特征

雅克拉凝析气田天然气组分以甲烷为主,含量79.13%￣89.30%;重烃含量较高,平均占9.67%;干燥系数(C1/C1-5)介于0.89～0.92之间,属典型的湿气。δ13C1为-40.8‰～-39.4‰,δ13C2为-32.0‰～-30.2‰,δ13C3为-30.5‰～-28.9‰,表明天然气为典型的油型气。原油及其族组分的碳同位素组成和生物标志化合物呈现出典型的海相原油特征。原油成熟度较高,与天然气的成熟度基本相同,表明油气同源、同阶,为一次油气充注的产物,而与塔河油田存在较大差异。

Geochemical Characteristics of hydrocarbon in Yakela Gas Condensate Field,Tarim Basin

Geochemical analysis of hydrocarbon in Yakela Field shows that natural gas is characterized by dominant methane in content with a range of 79.13%～89.30% and by high content of heavy hydrocarbon with of average 9.67% and low dry coefficient (C1/C1-5) of 0.89～0.92, which suggests it is a typical wet gas. Carbon isotopic values of heavy gaseous hydrocarbon in which δ13C1 is -40.8 ‰ ~-39.4 ‰, δ13C2 is -32.0 ‰ ~-30.2 ‰ and δ13C3 is -30.5 ‰ ~-28.9 ‰ demonstrate that the gas is oil-prone. According to the chemical and carbon isotopic compositions of crude oil and the biomarker characteristics,the crude oil in the field derived from marine sources. The crude oil has been at high stage of maturity that is almost consistent with natural gas,which is inferred that both the oil and the gas are the products during one time of hydrocarbon-filling history so that the hydrocarbon in Yakela Condensate Field is distinct from that in Tahe oil Field.