论乙烷碳同位素在天然气成因类型研究中的应用

CARBON ISOTOPE OF ETHANE APPLIED IN THE ANALYSES OF GENETIC TYPES OF NATURAL GAS

刚文哲 高岗 郝石生 黄志龙 朱雷

Gang Wenzhe Gao Gang Hao Shisheng Zhu Lei

石油大学, 北京, 102200

University of Petroleum, Beijing

本文利用加水热压模拟实验的方法研究了碳酸盐岩、泥岩、油页岩和煤热解气中乙烷碳同位素随成熟度的演化规律,发现腐泥型热解气和腐殖型热解气的乙烷同位素具有明显的母质继承性,其分布具有明显的区别。即腐泥型热解气的乙烷碳同位素小于-29‰,而腐殖型热解气的乙烷碳同位素大干-29‰;从我国天然气乙烷碳同位素的统计结果看也有这-规律。因此,无论从模拟实验的范果,还是从实际统计的结果均说明以乙烷碳同位素-29‰可以作为区分腐泥型天然气和腐殖型天然气成因类型的标准。笔者应用这一标准研究了塔里木盆地天然气的成因类型,取得了良好的效果。

The correlation of carbon isotope of ethane and maturity is srudied by hydrous pyrolyses of carbonate rock, mudstone, oil shale, and coal. It is found that the carbon isotope of ethane both for sapropelic pyrolytic gas and humic pyrolytic gas obviousy shows an inheritance of mother materials, however, there is a differnece in their distributions for the two types of gas. In other words, the δl3C value of ethane for sapropelic natural gas is smal1er than -29%,(PDB), while the δl3C value for humic natural gas is greater than -29%,(PDB). It is concluded that the results either from hydrous pyrolytic experiments or from actual statistic figures indicate that δl3C value -29%, of ethane can be taken as a criterion to determine the genetic types of sapropelic or humic natural gas. It was used in studying the genetic types of natural gas in Tarim basin, which achieved good results.

https://doi.org/10.11781/sysydz199702164