松辽盆地红岗地区浅层气地球化学特征研究

Geochemical characteristics of shallow gas in Honggang region,Songliao Basin

根据红岗地区7件明水组浅层气和13件嫩江组浅层气样品的组分和同位素分析,表明明水组浅层气甲烷含量、重烃含量、干燥系数、δ13C1均值分别为92.74%,1.77%,0.981,-56.7‰,而嫩江组浅层气甲烷含量、重烃含量、干燥系数、δ13C1均值分别为90.38%,5.57%,0.942,-52.1‰。明水组浅层气主要为生物气,而嫩江组浅层气属于生物—热催化过渡带气,都属于低熟油型气。

The chemical and stable carbon isotopic compositions of 7 shallow gas samples from the Mingshui Formation and 13 shallow gas samples from the Nenjiang Formation in Honggang region have been tested.Results have indicated that the average values of CH4 content,C2＋ content,dry coefficient and δ13C1 of the Mingshui Formation are 92.74%,1.77%,0.981 and-56.7‰,respectively,while those of the Nenjiang Formation are 90.38%,5.57%,0.942 and-52.1‰,respectively.The shallow gas from the Mingshui Formation is biogas and that from the Nenjiang Formation is bio-thermocatalytic transitional gas.Both of them belong to low-mature oil-type gas.