地表化探中甲烷稳定碳同位素的应用及存在问题  

THE APPLICATION OF δ^(13)C_1 TO SURFACE GEOCHEMICAL EXPLORATION AND ITS EXISTING PROBLEMS

作　　者：王国建[1] 程同锦[1] 汤玉平[1] 黄欣[1] 朱怀平[1] 

机构地区：[1]中国石化石油勘探开发研究院无锡石油地质研究所

出　　处：《物探与化探》2008年第5期549-552,共4页Geophysical and Geochemical Exploration

基　　金：中国石化科技开发项目(P05069)

摘　　要：甲烷稳定碳同位素组成(1δ3C1)作为气态烃的示踪剂,是近地表油气化探中常用的判别烃类来源的方法。油气化探中分析土壤中不同赋存状态的烃类的甲烷稳定碳同位素,一直沿用有机地球化学中的标准来确定地表土壤中的烃类属何种成因,所获得的结果往往令人难以信服。通过对已知区近地表土壤不同赋存状态烃类的甲烷碳同位素特征分析,认为由于分馏现象、成壤母岩、运移机制等,近地表化探烃类异常的甲烷碳同位素有其自身的特点,在应用时应考虑甲烷碳同位素比值的干扰因素,从而把地表痕量轻烃稳定碳同位素与地下深部油气建立相应的联系,反映真假异常,提高油气化探异常的可信度。δ^13C1 , as a tracer of gas hydrocarbon, serves as a method for judging the source of hydrocarbon in surface geochemical exploration. The δ^13C1 criterion of organic geochemistry is always used to ascertain the origin of hydrocarbon in soil by analyzing different modes of occurrence of hydrocarbon, but the results are generally not convincing. Based on an analysis of δ^13C1 in different modes of occurrence of hydrocarbon in soil over known areas, it is thought that δ^13C1 in anomalous hydrocarbon has its own characteristics because of such affecting factors as fractionation and parent rock migration mechanism. The interfering factors must he considered when δ^13C1 is applied so as to establish the relationship between δ^13C1 of trace hydrocarbon at surface and that in oil/gas accumulation. On such a basis, real anomalies can be distinguished from false ones, and hence reliability of SGE anomaly can be improved.

关 键 词：δ^13C1 示踪剂 地表化探 赋存状态 干扰因素 油气化探异常 

分 类 号：P632[天文地球—地质矿产勘探]