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阿克莫木气藏,柯克亚—柯东气藏天然气地化特征差异明显,天然气类型及气源岩一直存在争议.通过对塔西南坳陷山前带天然气稳定碳氢同位素及轻烃组成特征的分析,研究了天然气成因类型,并在此基础上,进行了气源对比,明确了气源岩类型.综合运用轻烃三角图版、稳定碳同位素图版、Mango参数、Whiticar图版及碳氢同位素图版,认为阿克莫木气藏为来自于下侏罗统的煤成气,柯克亚—柯东气藏为来自于石炭系及侏罗系混源成因的天然气.研究结果表明:阿克莫木气藏干燥系数接近1,δ~(13)C_1值为-24.2‰~-23.3‰,是塔西南坳陷山前带最重的,为来源单一的煤成气;而柯克亚—柯东气藏干燥系数均小于0.90,且存在单项性碳同位素倒转,为混源成因的湿气.前者气源岩主要为下侏罗统康苏组,干酪根以Ⅲ型为主;后者气源岩为石炭系,同时混有侏罗系气源岩,干酪根以Ⅱ-Ⅲ型为主.阿克莫木气藏苯的体积分数高达31.10%~37.38%,甲苯的体积分数为9.63%~13.46%,天然气成熟度远大于柯克亚—柯东气藏.
There are significant differences in geochemical features of natural gas in the Kekeya-Cundong gas reservoir, natural gas types and gas source rocks in the Ackromuqi gas pool, and the gas source rock has been controversial.According to the stable hydrocarbon isotope and light hydrocarbon composition of the natural gas in the foreland zone in the southwestern Tarim Basin, Characteristics of gas genesis, and on the basis of which, the source of gas is contrasted and the type of gas source rock is defined.Combining the light hydrocarbon triangular plate, stable carbon isotope plate, Mango parameter, Whiticar plate and hydrocarbon isotope Plate, that the Akemo gas reservoir is from the lower Jurassic coal gas, Kekeya - Ke Dong gas from the Carboniferous and Jurassic mixed source genesis of natural gas.The results show that: Ake The dry coefficient of MoMu gas reservoir is close to 1 and the δ 13 C 1 value is -24.2 ‰ -23.3 ‰, which is the heaviest piedmont zone in the southwestern Tarim Basin and is a single source of coal-derived gas. However, The drying coefficient of the Kendong gas reservoir are all less than 0.90, and there is inversion of individual carbon isotopes, which is the source of mixed-sourced moisture.The former gas source rocks are mainly the Lower Jurassic Kangsu Formation and the kerogen type Ⅲ mainly; The rocks are Carboniferous, mixed with Jurassic gas source rocks, and kerogen is mainly Ⅱ-Ⅲ type. The volume fraction of benzene in the Amico gas reservoir is as high as 31.10% -37.38%, the volume fraction of toluene is 9.63% -13.46%, and the maturity of natural gas is much larger than that of the Kekeya-Kendong gas reservoir.