ABSTRACT
The isotope characteristics of gas were normal and not reversal in this zone, which indicated that the gas genesis was organic origin (Dai & Xia & Qin et al). The carbon isotope characteristics of natural gas were that the carbon isotope of methane was overly light and the carbon isotope of heavy hydrocarbon heavy (Fig. 4). The carbon isotope of methane (δ13C1) was range from −42.10 to −35.60‰, the carbon isotope of ethane (δ13C2) was range from −29.09‰ to −24.40‰, the carbon isotope of propane (δ13C3) was range from −27.51‰ to −22.5‰, he carbon isotope of n-butane was range from −27.05‰ to −22.80‰.
